JP2025037087A - Laminate - Google Patents

Abstract

To provide a laminate excellent in flame retardancy.SOLUTION: A laminate 100 includes: a first fiber region 1 including a first fiber 34; a first flame retardant region 11 including a cured product of a first resin composition including first flame retardant constituents 37, 42; and a second fiber region 2 including a second fiber 44, in sequence toward one direction side in a thickness direction. The first fiber 34 and the second fiber 44 are single fibers and/or fiber bundles constituted by bundling 1 or more and 150 or less of a single fiber having a fiber diameter of 6 μm or more and 20 μm or less. The mass of the first fiber 34 per unit area is 150 g/m2 or more and 1000 g/m2 or less in the first fiber region 1. The mass of the second fiber 44 per unit area is 150 g/m2 or more and 1000 g/m2 or less in the second fiber region 2. The first flame retardant constituents 37, 42 include a powdery flame retardant.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminate.

Conventionally, molded articles made from molding materials containing unsaturated polyester resin compositions (particularly sheet molding compounds (SMC), bulk molding compounds (BMC), and thick molding compounds (TMC)) have been used in a wide range of fields due to their excellent mechanical properties, water resistance, and corrosion resistance.

On the other hand, such molded products are required to be flame retardant depending on their application and purpose.

As such a molded product, for example, a laminate has been proposed that includes a molded layer made of reinforcing fibers and a cured product of an unsaturated polyester resin composition, and a heat insulating layer made of an inorganic nonwoven fabric and a cured product of an unsaturated polyester resin composition (see, for example, Patent Document 1 below).

International Publication No. 2022/264661 Brochure

On the other hand, molded products require even greater flame retardancy.

The present invention provides a laminate with excellent flame retardancy.

The present invention [1] is a laminate comprising a first fiber region including a first fiber, a first flame-retardant region including a cured product of a first resin composition including a first flame-retardant component, and a second fiber region including a second fiber, which are arranged in this order toward one side in a thickness direction, wherein the first fiber and the second fiber are single fibers and/or fiber bundles including 1 to 150 single fibers having a fiber diameter of 6 μm to 20 μm, the mass per unit area of the first fiber in the first fiber region being 150 g/ ^m2 to 1000 g/ ^m2 , the mass per unit area of the second fiber in the second fiber region being 150 g/ ^m2 to 1000 g/ ^m2 , and the first flame-retardant component including a powdery flame retardant.

With this configuration, the first fiber region and the second fiber region limit the movement of the first flame retardant component in the thickness direction. Therefore, a first flame retardant region containing a localized first flame retardant component can be formed between the first fiber region and the second fiber region. As a result, the flame retardancy can be improved.

The present invention [2] includes the laminate described in [1] above, which includes a second flame-retardant region on the other thickness-wise side of the first fiber region, the second flame-retardant region including a cured product of a second resin composition including a second flame-retardant component, the second flame-retardant component including expandable graphite and/or a powdered flame retardant, and a third flame-retardant region on one thickness-wise side of the second fiber region, the third flame-retardant region including a cured product of a third resin composition including a third flame-retardant component, the third flame-retardant component including expandable graphite and/or a powdered flame retardant.

With this configuration, the first fiber region restricts the movement of the second flame retardant component in the thickness direction. This allows the formation of a second flame retardant region containing a localized second flame retardant component. The second fiber region restricts the movement of the third flame retardant component in the thickness direction. This allows the formation of a third flame retardant region containing a localized third flame retardant component. As a result, the flame retardancy can be improved.

The present invention [3] includes the laminate described in [2] above, in which, in one flame-retardant region and another flame-retardant region adjacent to the fiber region in the thickness direction, the one flame-retardant region does not contain expandable graphite but contains a powdered flame retardant, the other flame-retardant region contains expandable graphite and a powdered flame retardant, the fiber region is one selected from the group consisting of the first fiber region and the second fiber region, and the flame-retardant region is one selected from the group consisting of the first flame-retardant region, the second flame-retardant region, and the third flame-retardant region.

With this configuration, a flame-retardant region containing localized expanded graphite and powdered flame retardant is formed next to a flame-retardant region containing no expandable graphite but localized powdered flame retardant. This results in an expansion layer that is caused by the action of the expandable graphite during combustion, and a non-expansion layer that does not expand during combustion and maintains strength after combustion. The expansion layer suppresses temperature rise during fire resistance tests, while the non-expansion layer improves residual strength after combustion. As a result, flame retardancy can be improved.

The present invention [4] includes the laminate described in [2] above, in which the first flame retardant component does not contain expandable graphite, the second flame retardant component contains expandable graphite and a powdered flame retardant, and the third flame retardant component contains expandable graphite and a powdered flame retardant.

With this configuration, a flame-retardant region containing localized expanded graphite and powdered flame retardant is formed next to a flame-retardant region containing no expandable graphite but localized powdered flame retardant. This results in an expansion layer that is caused by the action of the expandable graphite during combustion, and a non-expansion layer that does not expand during combustion and maintains strength after combustion. The expansion layer suppresses temperature rise during fire resistance tests, while the non-expansion layer improves residual strength after combustion. As a result, flame retardancy can be improved.

The present invention [5] includes the laminate described in [2] above, in which the second flame-retardant region is a fiber bundle consisting of 151 or more single fibers, and includes chopped-strand or cross-shaped reinforcing fibers.

This configuration improves mechanical strength.

The present invention [6] includes the laminate described in [5] above, in which the first flame retardant component does not contain expandable graphite, the second flame retardant component does not contain expandable graphite and contains a powdered flame retardant, and the third flame retardant component contains expandable graphite and a powdered flame retardant.

This configuration improves flame retardancy.

The present invention [7] includes the laminate according to the above [1], further comprising a third flame-retardant region and a third fiber region including third fibers, which are arranged in that order toward one side in the thickness direction on one side of the second fiber region in the thickness direction, the third flame-retardant region including a cured product of a third resin composition including a third flame-retardant component, the third flame-retardant component including expandable graphite and/or a powdery flame retardant, the third fibers being single fibers and/or fiber bundles including 1 to 150 single fibers having a fiber diameter of 6 μm to 20 μm, and the mass per unit area of the third fibers in the third fiber region is 150 g/ ^m2 to 1000 g/ ^m2 .

With this configuration, the first fiber region and the second fiber region limit the movement of the first flame retardant component in the thickness direction. Therefore, a first flame retardant region containing a localized first flame retardant component can be formed between the first fiber region and the second fiber region.

The second and third fiber regions also restrict the movement of the third flame retardant component in the thickness direction. Therefore, a third flame retardant region containing a localized third flame retardant component can be formed between the second and third fiber regions. As a result, the flame retardancy can be improved.

The present invention [8] includes the laminate described in [7] above, which includes a second flame-retardant region on the other thickness-wise side of the first fiber region, the second flame-retardant region including a cured product of a second resin composition including a second flame-retardant component, the second flame-retardant component including expandable graphite and/or a powdered flame retardant, and a fourth flame-retardant region on one thickness-wise side of the third fiber region, the fourth flame-retardant region including a cured product of a fourth resin composition including a fourth flame-retardant component, the fourth flame-retardant component including expandable graphite and/or a powdered flame retardant.

With this configuration, the first fiber region restricts the movement of the second flame retardant component in the thickness direction. This allows the formation of a second flame retardant region that contains a localized second flame retardant component. The third fiber region restricts the movement of the fourth flame retardant component in the thickness direction. This allows the formation of a fourth flame retardant region that contains a localized fourth flame retardant component. As a result, the flame retardancy can be improved.

The present invention [9] includes the laminate described in [8] above, in which, in one flame-retardant region and another flame-retardant region adjacent to the fiber region in the thickness direction, the one flame-retardant region does not contain expandable graphite but contains a powdered flame retardant, the other flame-retardant region contains expandable graphite and a powdered flame retardant, the fiber region is one selected from the group consisting of the first fiber region, the second fiber region, and the third fiber region, and the flame-retardant region is one selected from the group consisting of the first flame-retardant region, the second flame-retardant region, the third flame-retardant region, and a fourth flame-retardant region.

With this configuration, a flame-retardant region containing localized expanded graphite and powdered flame retardant is formed next to a flame-retardant region containing no expandable graphite but localized powdered flame retardant. This results in an expansion layer that is caused by the action of the expandable graphite during combustion, and a non-expansion layer that does not expand during combustion and maintains strength after combustion. The expansion layer suppresses temperature rise during fire resistance tests, while the non-expansion layer improves residual strength after combustion. As a result, flame retardancy can be improved.

The present invention [10] includes the laminate described in [8] above, in which the first flame retardant component does not contain expanded graphite, the second flame retardant component contains expanded graphite and a powdered flame retardant, the third flame retardant component contains expanded graphite and a powdered flame retardant, and the fourth flame retardant component does not contain expanded graphite but contains a powdered flame retardant.

With this configuration, a flame-retardant region containing localized expanded graphite and powdered flame retardant is formed next to a flame-retardant region containing no expandable graphite but localized powdered flame retardant. This results in an expansion layer that is caused by the action of the expandable graphite during combustion, and a non-expansion layer that does not expand during combustion and maintains strength after combustion. The expansion layer suppresses temperature rise during fire resistance tests, while the non-expansion layer improves residual strength after combustion. As a result, flame retardancy can be improved.

The present invention [11] includes the laminate according to any one of the above [1] to [6], in which the first fibers are glass fibers, the mass per unit area of the first fibers in the first fiber region is 200 g/ ^m2 or more and 800 g/ ^m2 or less, and the second fibers are glass fibers, and the mass per unit area of the second fibers in the second fiber region is 200 g/ ^m2 or more and 800 g/ ^m2 or less.

This configuration further restricts the movement of the flame retardant components in the first fiber region and the second fiber region. This allows the flame retardant components to be further localized. As a result, the flame retardancy can be further improved.

The present invention [12] includes the laminate according to any one of the above [7] to [ ¹⁰ ], in which the first fibers are glass fibers, and in the first fiber region, the mass per unit area of the first fibers is 200 g/ ^m2 or more and 800 g/ ^m2 or less, the second fibers are glass fibers, and in the second fiber region, the mass per unit area of the second fibers is 200 g/m2 or more and 800 g/ ^m2 or less, and the third fibers are glass fibers, and in the third fiber region, the mass per unit area of the third fibers is 200 g/ ^m2 or more and 800 g/ ^m2 or less.

This configuration further restricts the movement of the flame retardant components in the first fiber region, the second fiber region, and the third fiber region. This allows the flame retardant components to be further localized. As a result, the flame retardancy can be further improved.

The present invention [13] includes the laminate described in [11] above, in which the powdered flame retardant has an average particle size of 10 μm or more and 200 μm or less.

This configuration ensures that the flame retardant components, including the powdered flame retardant, are localized (described below).

The present invention [14] includes the laminate described in [12] above, in which the powdered flame retardant has an average particle size of 10 μm or more and 200 μm or less.

This configuration ensures that the flame retardant components, including the powdered flame retardant, are localized (described below).

The laminate of the present invention has a first flame retardant region that is sandwiched in the thickness direction between a first fiber region that contains a predetermined first fiber and a second fiber region that contains a predetermined second fiber, and includes a powdered flame retardant. This improves flame retardancy.

FIG. 1 shows a cross-sectional view of a first embodiment of a laminate of the present invention. 2A to 2F are schematic diagrams showing an embodiment of the second step in the manufacturing method of the laminate of the first embodiment. FIG. 2A shows a step of applying a second resin composition to a surface on one side in the thickness direction of one separate film to form a second resin layer. FIG. 2B shows a step of introducing a first fiber 34 to a surface on one side in the thickness direction of the second resin layer. FIG. 2C shows a step of applying a first A resin composition to a surface on one side in the thickness direction of another separate film to form a first A resin layer. FIG. 2D shows a step of overlapping a surface on one side in the thickness direction of the second resin layer into which the first fiber has been introduced with the surface of the first A resin layer, and then applying pressure from the outside to manufacture a first SMC. FIG. 2E shows a cross-sectional view of the first SMC. FIG. 2F shows a cross-sectional view of the second SMC. 3A and 3B are schematic diagrams showing an embodiment of the third step in the manufacturing method of the laminate of the first embodiment. Fig. 3A shows a step of stacking the first SMC and the second SMC so that the surface on one side in the thickness direction of the first SMC and the surface on the other side in the thickness direction of the second SMC are in contact with each other, and then performing heat compression molding. Fig. 3B shows a cross-sectional view of the laminate. FIG. 4 shows a cross-sectional view of a second embodiment of a laminate of the present invention. 5A and 5B are schematic diagrams showing an embodiment of a method for producing a laminate of the second embodiment. Fig. 5A shows a second step of producing a plurality of molding materials (SMC). Fig. 5B shows a third step of stacking a plurality of molding materials (SMC) and heat-compressing the stacked SMCs. 6A and 6B are schematic diagrams showing the prior art: Fig. 6A shows a cross-sectional view of a conventional SMC, and Fig. 6B shows a cross-sectional view of a conventional laminate. 7A to 7C are schematic diagrams showing an embodiment of a method for producing a laminate of the first modified example. Fig. 7A shows a process for producing a first SMC and a second SMC in the second process. Fig. 7B shows a process for producing another SMC in the second process. Fig. 7C shows a third process in which a plurality of molding materials (SMCs) are stacked and heated and compressed to form the laminate. 8A to 8D are schematic diagrams showing an embodiment of a method for manufacturing a laminate of the second modified example. Fig. 8A shows a process of stacking the second resin layer, the first fiber, the 1A resin layer, the second fiber, and the third resin layer in order toward one side in the thickness direction and performing heat compression molding. Fig. 8B shows a cross-sectional view of the laminate. Fig. 8C shows a process of stacking another SMC, the first fiber, the 1A resin layer, the second fiber, and the third resin layer in order toward one side in the thickness direction and performing heat compression molding. Fig. 8D shows a cross-sectional view of the laminate. 9A to 9C are schematic diagrams showing an embodiment of a method for producing a laminate of the fourth modified example. Fig. 9A shows a process for producing a first SMC and a second SMC in the second process. Fig. 9B shows a third process in which a plurality of molding materials (SMCs) are stacked and heated and compressed. Fig. 9C shows a cross-sectional view of the laminate.

The laminate of the present invention has a first fiber region, a first flame-retardant region, and a second fiber region, arranged in that order toward one side in the thickness direction.

The following describes in detail a first embodiment in which the second flame-retardant region, the first fiber region, the first flame-retardant region, the second fiber region, and the third flame-retardant region are arranged in sequence toward one side in the thickness direction, and a second embodiment in which the second flame-retardant region, the first fiber region, the first flame-retardant region, the second fiber region, the third flame-retardant region, the third fiber region, and the fourth flame-retardant region are arranged in sequence toward one side in the thickness direction.

1. First embodiment As shown in FIG. 1 , the laminate 100 includes a second flame-retardant region 12, a first fiber region 1, a first flame-retardant region 11, a second fiber region 2, and a third flame-retardant region 13, which are arranged in this order toward one side in the thickness direction.

In other words, the laminate 100 has a second flame-retardant region 12 on the other thickness-wise side of the first fiber region 1. The laminate 100 also has a third flame-retardant region 13 on one thickness-wise side of the second fiber region 2.

Such a laminate 100 is obtained by obtaining multiple molding materials (SMC) using a known sheet molding compound (SMC) impregnation machine, stacking the multiple molding materials (SMC), and subjecting them to heat compression molding.

In detail, the method for manufacturing the laminate 100 includes a first step of preparing a resin composition, a second step of producing a plurality of molding materials (SMC), and a third step of stacking these molding materials (SMC) and subjecting them to heat compression molding.

<<First Step>>
In the first step, a resin composition is prepared.

The resin composition includes a resin component and a flame retardant component.

<Resin Component>
The resin component contains a thermosetting resin, a polymerizable monomer, and, if necessary, a low-shrinkage agent, and preferably contains an unsaturated polyester, a polymerizable monomer, and a low-shrinkage agent.

Examples of thermosetting resins include unsaturated polyester resins, vinyl ester resins, and acrylic syrups. A preferred example of a thermosetting resin is unsaturated polyester resin.

The unsaturated polyester resin contains an unsaturated polyester and a polymerizable monomer. In other words, the unsaturated polyester resin is an unsaturated polyester resin composition containing an unsaturated polyester and a polymerizable monomer.

(Unsaturated polyester)
The unsaturated polyester is obtained by reacting a polybasic acid with a polyhydric alcohol.

[Polybasic acid]
The polybasic acid includes a polybasic acid having an ethylenically unsaturated double bond as an essential component (hereinafter referred to as an ethylenically unsaturated bond-containing polybasic acid) and a polybasic acid not having an ethylenically unsaturated double bond as an optional component (hereinafter referred to as an ethylenically unsaturated bond-free polybasic acid).

{Polybasic acid containing an ethylenically unsaturated bond}
Examples of the ethylenically unsaturated bond-containing polybasic acid include ethylenically unsaturated aliphatic dibasic acids and their anhydrides, halides of ethylenically unsaturated aliphatic dibasic acids, and alkyl esters of ethylenically unsaturated aliphatic dibasic acids.

Examples of ethylenically unsaturated aliphatic dibasic acids include maleic acid, fumaric acid, itaconic acid, and dihydromuconic acid. Examples of ethylenically unsaturated bond-containing polybasic acids include acid anhydrides derived from the above ethylenically unsaturated aliphatic dibasic acids. Examples of acid anhydrides derived from ethylenically unsaturated aliphatic dibasic acids include maleic anhydride. Examples of ethylenically unsaturated bond-containing polybasic acids include maleic anhydride.

{Polybasic acid not containing an ethylenically unsaturated bond}
Examples of polybasic acids not containing ethylenically unsaturated bonds include saturated aliphatic polybasic acids, saturated alicyclic polybasic acids, aromatic polybasic acids, anhydrides of these acids, halides of these acids, and alkyl esters of these acids.

Examples of saturated aliphatic polybasic acids include saturated aliphatic dibasic acids.

Examples of saturated aliphatic dibasic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylsuccinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Saturated aliphatic polybasic acids include acid anhydrides derived from the above-mentioned saturated aliphatic dibasic acids. Examples of acid anhydrides derived from saturated aliphatic dibasic acids include oxalic anhydride and succinic anhydride.

Examples of saturated alicyclic polybasic acids include saturated alicyclic dibasic acids.

Examples of saturated alicyclic dibasic acids include HET acid, 1,2-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid (cis- or trans-1,4-cyclohexanedicarboxylic acid or a mixture thereof). Examples of saturated alicyclic polybasic acids include acid anhydrides derived from the above-mentioned saturated alicyclic dibasic acids. Examples of acid anhydrides derived from saturated alicyclic dibasic acids include HET acid anhydride.

Examples of aromatic polybasic acids include aromatic dibasic acids.

Examples of aromatic dibasic acids include phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid), trimellitic acid, and pyromellitic acid. Examples of aromatic polybasic acids include acid anhydrides derived from the above aromatic dibasic acids. Examples of acid anhydrides derived from aromatic dibasic acids include phthalic anhydride.

Polybasic acids can be used alone or in combination of two or more types.

When the polybasic acid includes an ethylenically unsaturated bond-containing polybasic acid and an ethylenically unsaturated bond-free polybasic acid, the content of the ethylenically unsaturated bond-containing polybasic acid relative to 100 moles of the total polybasic acid is, for example, 20 mol% or more, preferably 50 mol% or more.

[Polyhydric alcohol]
Polyhydric alcohols include, for example, dihydric and trihydric alcohols.

Examples of dihydric alcohols include aliphatic diols, alicyclic diols, and aromatic diols. Examples of aliphatic diols include alkane diols and ether diols. Examples of alkane diols include alkane diols having 2 to 10 carbon atoms. Examples of alkane diols having 2 to 10 carbon atoms include ethylene glycol, propylene glycol (1,2- or 1,3-propane diol or a mixture thereof), butylene glycol (1,2- or 1,3- or 1,4-butylene glycol or a mixture thereof), 1,5-pentane diol, 1,6-hexane diol, neopentyl glycol, 2-methyl-1,3-propane diol, 2-butyl-2-ethyl-1,3-propane diol, 3-methyl-1,5-pentane diol, 2,2,2-trimethylpentane diol, and 3,3-dimethylol heptane. Examples of ether diols include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of alicyclic diols include cyclohexanediol (1,2- or 1,3- or 1,4-cyclohexanediol or a mixture thereof), cyclohexanedimethanol (1,2- or 1,3- or 1,4-cyclohexanedimethanol or a mixture thereof), cyclohexanediethanol (1,2- or 1,3- or 1,4-cyclohexanediethanol or a mixture thereof), and hydrogenated bisphenol A. Examples of aromatic diols include an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A.

Examples of trihydric alcohols include glycerin, trimethylolpropane, and triisopropanolamine.

As the polyhydric alcohol, preferably, a dihydric alcohol is used. As the polyhydric alcohol, more preferably, an aliphatic diol is used. As the polyhydric alcohol, even more preferably, an alkanediol having 2 to 10 carbon atoms is used. As the polyhydric alcohol, particularly preferably, an alkanediol is used. As the polyhydric alcohol, most preferably, propylene glycol is used.

Polyhydric alcohols can be used alone or in combination of two or more types.

[Reaction of polybasic acid with polyhydric alcohol]
Unsaturated polyesters are prepared by reacting a polybasic acid with a polyhydric alcohol.

The equivalent ratio of polyhydric alcohol to polybasic acid (hydroxyl groups of polyhydric alcohol/carboxyl groups of polybasic acid) is, for example, 0.9 or more, preferably 0.95 or more, and, for example, 1.2 or less, preferably 1.1 or less.

The reaction temperature is, for example, 150°C or higher, preferably 190°C or higher, and, for example, 250°C or lower, preferably 230°C or lower.

In addition, in the above reaction, known solvents, known reaction catalysts, and known additives can also be added as necessary.

This allows the preparation of unsaturated polyesters. Unsaturated polyesters can also be modified with dicyclopentadiene (DCPD).

The acid value of the unsaturated polyester (measurement method: in accordance with JIS K6901 (2008)) is, for example, 10 mgKOH/g or more, preferably 15 mgKOH/g or more, more preferably 20 mgKOH/g or more, and, for example, less than 40 mgKOH/g, preferably 30 mgKOH/g or less, more preferably 25 mgKOH/g or less.

The weight average molecular weight of the unsaturated polyester is, for example, 2,000 or more, preferably 4,000 or more, and, for example, 25,000 or less, preferably 20,000 or less.

The weight average molecular weight is the weight average molecular weight calculated using polystyrene standards by GPC (gel permeation chromatography).

Unsaturated polyesters can be used alone or in combination of two or more types.

The content of the unsaturated polyester is, for example, 20 parts by mass or more, preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and, for example, 60 parts by mass or less, preferably 50 parts by mass or less, per 100 parts by mass of the resin component.

(Polymerizable monomer)
Examples of the polymerizable monomer include styrene-based monomers and (meth)acrylic acid ester-based monomers.

Examples of styrene monomers include styrene, vinyltoluene, t-butylstyrene, and chlorostyrene.

Examples of (meth)acrylic acid ester monomers include (meth)acrylic acid alkyl esters, (meth)acrylic acid allyl esters, ring-containing (meth)acrylic acid esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid aminoalkyl esters, (meth)acrylic acid fluoroalkyl esters, and polyfunctional (meth)acrylic acid esters. Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate), 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate. Examples of (meth)acrylic acid allyl esters include allyl (meth)acrylate. Examples of ring-structure-containing (meth)acrylic acid esters include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. Examples of hydroxyalkyl (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. Examples of alkoxyalkyl (meth)acrylic acid esters include 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate. Examples of aminoalkyl (meth)acrylic acid esters include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and chloride salts thereof. Examples of (meth)acrylic acid fluoroalkyl esters include trifluoroethyl (meth)acrylate and heptadecafluorodecyl (meth)acrylate. Examples of polyfunctional (meth)acrylic acid esters include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

As the polymerizable monomer, preferably, a styrene-based monomer and an alkyl (meth)acrylate ester are used. As the polymerizable monomer, more preferably, styrene and methyl methacrylate are used. As the polymerizable monomer, even more preferably, styrene is used.

The polymerizable monomers can be used alone or in combination of two or more types.

The content of the polymerizable monomer is, for example, 30 parts by mass or more, preferably 40 parts by mass or more, and, for example, 70 parts by mass or less, preferably 60 parts by mass or less, per 100 parts by mass of the resin component.

(Low profile agent)
The low shrinkage agent is added to suppress cure shrinkage and thermal shrinkage and to improve the appearance.

Examples of low shrinkage agents include polyethylene, polystyrene, crosslinked polystyrene, polyvinyl acetate-polystyrene block copolymers, polyvinyl acetate, polymethyl methacrylate, styrene-based thermoplastic elastomers, and saturated polyester resins.

It is also possible to prepare a polymerizable monomer solution of the low shrinkage agent by dissolving the low shrinkage agent in the above-mentioned polymerizable monomer.

In the polymerizable monomer solution of the shrinkage reducing agent, the solids concentration of the shrinkage reducing agent is, for example, 20% by mass or more, and, for example, 70% by mass or less, preferably 50% by mass or less.

Shrinkage reducing agents can be used alone or in combination of two or more types.

The content of the shrinkage reducing agent is, for example, 2 parts by mass or more, preferably 5 parts by mass or more, and, for example, 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the resin component.

As will be described in more detail later, in the method for producing the laminate 100, in the second step, a molding material (SMC) is produced from multiple resin layers. To produce multiple resin layers, multiple resin compositions are produced, and preferably the resin components in the multiple resin compositions are the same.

The content of the resin component is, for example, 30% by mass or more, preferably 40% by mass or more, and, for example, 60% by mass or less, preferably 50% by mass or less, relative to the resin composition.

<Flame retardant components>
Examples of the flame retardant component include powdered flame retardants (excluding expandable graphite) and expandable graphite.

[Powder flame retardant]
The powdered flame retardant is a solid (25°C) and is a flame retardant grain or powder, specifically, a solid having an average particle size of 10 μm or more and 200 μm or less, preferably 100 μm or less, and more preferably 60 μm or less.

If the average particle size of the powdered flame retardant is equal to or greater than the lower limit, the flame retardant components including the powdered flame retardant can be reliably localized (described below).

In addition, if the average particle size of the powdered flame retardant is equal to or less than the above upper limit, the mechanical properties are excellent.

The average particle size of the powdered flame retardant can be determined by creating a particle size distribution curve using a laser diffraction/scattering particle size distribution measuring device and calculating the 50% by mass equivalent particle size. The powdered flame retardant does not contain aluminum hydroxide, which will be described later.

Powdered flame retardants include, for example, halogen-based flame retardants and non-halogen-based flame retardants.

Examples of halogen-based flame retardants include bromine-based flame retardants. Bromine-based flame retardants include hexabromobenzene, tetrabromobisphenol, bromodiphenyls (e.g., tetrabromodiphenyl), and bromodiphenyl ethers (e.g., tetrabromodiphenyl ether).

Non-halogen flame retardants include, for example, phosphorus-based flame retardants, inorganic flame retardants, and nitrogen-based flame retardants.

Examples of phosphorus-based flame retardants include red phosphorus, phosphate esters (e.g., trimethyl phosphate, triethyl phosphate, tributyl phosphate, tricresyl phosphate), polyphosphates (e.g., aluminum trisdiethylphosphinate), IFR (Intumescent) type intumescent flame retardants containing ammonium polyphosphate, an auxiliary such as pentaerythritol, and a carbon donor such as melamine, and metal phosphinates. Examples of phosphorus-based flame retardants include metal phosphinates and polyphosphates, preferably.

Inorganic flame retardants include, for example, antimony oxide (e.g., diantimony trioxide), zinc stannate, zinc borate, and preparations thereof.

Examples of nitrogen-based flame retardants include azoalkane compounds, hindered amine compounds, and melamine cyanurate. A preferred nitrogen-based flame retardant is melamine cyanurate.

As the powdered flame retardant, preferably, a non-halogen-based flame retardant is used. As the powdered flame retardant, more preferably, a phosphorus-based flame retardant or a nitrogen-based flame retardant is used. That is, more preferably, the powdered flame retardant includes a phosphorus-based flame retardant and/or a nitrogen-based flame retardant.

If the powdered flame retardant contains a phosphorus-based flame retardant and/or a nitrogen-based flame retardant, the flame retardancy can be further improved.

More preferably, the powdered flame retardant includes a phosphorus-based flame retardant and a nitrogen-based flame retardant. When the powdered flame retardant includes a phosphorus-based flame retardant and a nitrogen-based flame retardant, the content ratio of the phosphorus-based flame retardant is, for example, 30 parts by mass or more, preferably 40 parts by mass or more, more preferably 45 parts by mass or more, and for example, 70 parts by mass or less, preferably 60 parts by mass or less, and more preferably 55 parts by mass or less, relative to 100 parts by mass of the total amount of the phosphorus-based flame retardant and the nitrogen-based flame retardant. The content ratio of the nitrogen-based flame retardant is, for example, 30 parts by mass or more, preferably 40 parts by mass or more, more preferably 45 parts by mass or more, and for example, 70 parts by mass or less, preferably 60 parts by mass or less, and more preferably 55 parts by mass or less, relative to 100 parts by mass of the total amount of the phosphorus-based flame retardant and the nitrogen-based flame retardant.

Powdered flame retardants can be used alone or in combination of two or more types.

The content of the powdered flame retardant is, for example, 5 parts by mass or more, preferably 15 parts by mass or more, and 35 parts by mass or less, preferably 25 parts by mass or less, per 100 parts by mass of the resin component.

[Expanded graphite]
Expandable graphite is a graphite intercalation compound in which sulfuric acid or the like is inserted between the layers of flake-like natural graphite. This type of expandable graphite expands between the layers at temperatures of about 150 to 300°C.

Expanded graphite can be used alone or in combination of two or more types.

The content of expanded graphite is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and 10 parts by mass or less, preferably 5 parts by mass or less, per 100 parts by mass of the resin component.

The average particle size of the expanded graphite is, for example, 10 μm or more, and, for example, 200 μm or less, preferably 100 μm or less, and more preferably 60 μm or less.

If the average particle size of the expanded graphite is equal to or greater than the lower limit, the flame-retardant components, including the expanded graphite, can be reliably localized (described below).

In addition, if the average particle size of the expanded graphite is equal to or less than the above upper limit, the mechanical properties are excellent.

The average particle size of the expanded graphite can be determined by observing with an optical microscope, measuring the maximum diameter (long diameter) and the particle diameter (short diameter) perpendicular to the maximum diameter for 50 randomly selected powdered flame retardants, and calculating the average value of the long diameter and short diameter.

The content of the flame retardant component is, for example, 1 part by mass or more, preferably 5 parts by mass or more, more preferably 12 parts by mass or more, and, for example, 30 parts by mass or less, preferably 23 parts by mass or less, per 100 parts by mass of the resin component.

The content of the flame retardant component is, for example, 3% by mass or more, preferably 5% by mass or more, and, for example, 30% by mass or less, preferably 20% by mass or less, relative to the resin composition.

As will be described in detail later, in the method for producing the laminate 100, in the second step, a molding material (SMC) is produced from multiple resin layers. To produce multiple resin layers, multiple resin compositions are produced, and as will be described in detail later, the flame retardant components in the multiple resin compositions are the same or different from each other.

<Additives>
If necessary, additives may be blended into the resin composition within the range that does not impair the effects of the present invention.

Additives include, for example, fillers, polymerization inhibitors, curing agents, release agents, thickeners, colorants, wetting and dispersing agents, pattern materials, antibacterial agents, hydrophilic agents, photocatalysts, UV absorbers, UV stabilizers, separation inhibitors, silane coupling agents, antistatic agents, thixotropic agents, thixotropic stabilizers, and polymerization accelerators. Additives can be used alone or in combination of two or more types.

[Filling material]
Examples of the filler include inorganic fillers. Examples of the inorganic filler include oxides (e.g., alumina, titanium oxide), hydroxides (e.g., magnesium hydroxide, aluminum hydroxide), carbonates (e.g., calcium carbonate), sulfates (e.g., barium sulfate), silica (e.g., crystalline silica, fused silica, fumed silica, dry silica (aerosil)), hollow fillers, silicates (e.g., silica sand, diatomaceous earth, glass powder, glass balloons, mica, clay, kaolin, talc), fluorides (e.g., fluorite), phosphates (e.g., calcium phosphate), metal powders, ceramics, milled fibers, and clay minerals (e.g., smectite). Examples of the filler include, preferably, hydroxides. Examples of the filler include, more preferably, aluminum hydroxide.

Fillers can be used alone or in combination of two or more types.

The filler content is, for example, 50 parts by mass or more, preferably 70 parts by mass or more, and, for example, 200 parts by mass or less, preferably 150 parts by mass or less, per 100 parts by mass of the resin component.

The filler content is, for example, 20% by mass or more, preferably 40% by mass or more, and, for example, 70% by mass or less, preferably 60% by mass or less, relative to the resin composition.

[Polymerization inhibitor]
The polymerization inhibitor is added to adjust the pot life and the curing reaction.

Examples of polymerization inhibitors include hydroquinone compounds, benzoquinone compounds, catechol compounds, phenol compounds, and N-oxyl compounds.

Preferred examples of the polymerization inhibitor include benzoquinone compounds, hydroquinone compounds, and N-oxyl compounds.

An example of a benzoquinone compound is parabenzoquinone.

Examples of hydroquinone compounds include hydroquinone, methylhydroquinone, and t-butylhydroquinone.

The polymerization inhibitor is preferably a benzoquinone compound (parabenzoquinone).

The content of the polymerization inhibitor is, for example, 0.01 parts by mass or more, preferably 0.03 parts by mass or more, and, for example, 0.5 parts by mass or less, preferably 0.2 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the resin component.

[Curing agent]
Examples of the curing agent include peroxides. Examples of the peroxides include benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amylperoxyisopropyl carbonate, t-hexylperoxyisopropyl monocarbonate, 1,1-bis(t-butylperoxy)cyclohexane, t-butylperoxy-2-ethylhexanoate, amylperoxy-2-ethylhexanoate, 2-ethylhexylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, t-hexylperoxybenzoate, and t-hexylperoxyacetate. Examples of the curing agent include t-butylperoxyisopropyl carbonate.

Hardeners can be used alone or in combination of two or more types.

The content of the curing agent is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and, for example, 5 parts by mass or less, preferably 2 parts by mass or less, per 100 parts by mass of the resin component.

[Release agent]
Examples of the release agent include fatty acids, fatty acid metal salts, liquid wax, fluoropolymers, and silicon-based polymers. Examples of the fatty acids include stearic acid and lauric acid. Examples of the fatty acid metal salts include zinc stearate and calcium stearate. Examples of the release agent include fatty acid metal salts. Examples of the release agent include zinc stearate.

Release agents can be used alone or in combination of two or more types.

The content of the release agent is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and, for example, 10 parts by mass or less, per 100 parts by mass of the resin component.

[Thickener]
The thickener is blended in order to thicken the resin composition to a viscosity suitable for heat compression molding. The thickener is preferably blended before (preferably immediately before) impregnating the resin composition into the fibers.

Examples of thickeners include alkaline earth metal oxides and alkaline earth metal hydroxides. Examples of alkaline earth metal oxides include magnesium oxide. Examples of alkaline earth metal hydroxides include magnesium hydroxide and calcium hydroxide.

As the thickener, preferably, an alkaline earth metal oxide is used. As the thickener, more preferably, magnesium oxide is used.

Thickeners can be used alone or in combination of two or more types.

The content of the thickener is, for example, 0.5 parts by mass or more and, for example, 10 parts by mass or less, preferably 3 parts by mass or less, per 100 parts by mass of the resin component.

<Preparation of Resin Composition>
The resin composition is prepared by blending a resin component, a flame retardant component, and additives that are blended as required.

In the above preparation, the unsaturated polyester resin (a mixture of unsaturated polyester and polymerizable monomer) can be prepared by dissolving the unsaturated polyester in a polymerizable monomer (preferably styrene) in advance and, if necessary, adding the above-mentioned additives.

In preparing the unsaturated polyester resin, the content of the polymerizable monomer is, for example, 50 parts by mass or more, preferably 60 parts by mass or more, and, for example, 80 parts by mass or less, preferably 70 parts by mass or less, per 100 parts by mass of the unsaturated polyester.

After preparing the unsaturated polyester resin, a polymerizable monomer can be further added when blending the unsaturated polyester resin with the optional shrinkage reducing agent, flame retardant component, and optional additives.

This prepares the resin composition.

<<Second step>>
In the second step, a plurality of molding materials (SMC) are produced. Specifically, two molding materials (SMC) are produced. The molding materials (SMC) are produced using a known SMC impregnation machine.

In the following description, the resin composition (resin composition containing a flame retardant component and a resin component) constituting the Nth resin layer is referred to as the Nth resin composition (Nth resin composition containing the Nth flame retardant component and the Nth resin component). For example, the resin composition (resin composition containing a flame retardant component and a resin component) constituting the 1A resin layer 36 is referred to as the 1A resin composition (1A resin composition containing the 1A flame retardant component 37 and the 1A resin component 38).

First, as shown in FIG. 2A, a second resin composition is applied to one surface in the thickness direction of one separate film 30 to form a second resin layer 31. At this time, in the second resin layer 31, the second flame retardant component 32 is dispersed in the second resin component 33.

Next, as shown in FIG. 2B, the first fibers 34 are introduced onto one side of the second resin layer 31 in the thickness direction.

The first fiber 34 is a fiber (hereinafter, sometimes referred to as a filter fiber) that can form an area having a function (hereinafter, referred to as a filter function) of suppressing the mutual movement of the flame retardant components (the second flame retardant component 32 and the first A flame retardant component 37) in the thickness direction (the second flame retardant component 32 moving to the first A resin layer 36, and the first A flame retardant component 37 moving to the second resin layer 31) in the third process described below.

The first fiber 34 is a single fiber and/or a fiber bundle consisting of 1 to 150 single fibers each having a fiber diameter of 6 μm to 20 μm.

Examples of the first fibers 34 include inorganic fibers, organic fibers, and natural fibers. Examples of the inorganic fibers include glass fibers, carbon fibers, metal fibers, and ceramic fibers. Examples of the organic fibers include polyvinyl alcohol-based fibers, polyester-based fibers, polyamide-based fibers, fluororesin-based fibers, and phenol-based fibers. Examples of the natural fibers include hemp and kenaf.

The first fibers 34 are preferably inorganic fibers. The reinforcing fibers are more preferably glass fibers.

The basis weight of the first fibers 34 is, for example, 200 g/m ² or more and, for example, 700 g/m ² or less.

The shape of the first fibers 34 can be, for example, a felt shape, a cloth shape (for example, a roving cloth), or a chopped shape. The shape of the first fibers 34 is preferably a felt shape.

The length of the first fiber 34 is, for example, 1.5 mm or more, and from the viewpoint of improving strength, is preferably 5 mm or more, more preferably 20 mm or more, and is, for example, 80 mm or less, preferably 40 mm or less.

The content of the first fiber 34 relative to the first SMC 39 (described later) is, for example, 15% by mass or more, and, for example, 60% by mass or less, preferably 40% by mass or less.

Separately, as shown in FIG. 2C, the 1A resin composition is applied to one surface in the thickness direction of another separate film 35 to form a 1A resin layer 36. At this time, in the 1A resin layer 36, the 1A flame retardant component 37 is dispersed in the 1A resin component 38.

Then, as shown in FIG. 2D, the surface on one side in the thickness direction of the second resin layer 31 into which the first fibers 34 have been introduced is overlapped with the surface of the first A resin layer 36, and then pressure is applied from the outside. In this way, the first SMC 39 is produced.

As shown in FIG. 2E, in the first SMC 39, the filter function restricts the movement of the second flame retardant component 32 and the first A flame retardant component 37 in the thickness direction, and the second flame retardant component 32 and the first A flame retardant component 37 are separated by the first fiber 34. More specifically, in the first SMC 39, the second flame retardant component 32 is localized on the other side in the thickness direction, and the first A flame retardant component 37 is localized on one side in the thickness direction.

In other words, the first SMC 39 has, in order toward one side in the thickness direction, a second flame-retardant region 12' containing localized second flame-retardant component 32 and second resin component 33, a first fiber region 1' containing first fibers 34, second resin component 33 and first A resin component 38, and a first A flame-retardant region 40' containing localized first A flame-retardant component 37 and first A resin component 38.

In addition, in each region, the flame-retardant region with a "" next to the symbol indicates the region before curing, and the region without a "" next to the symbol indicates the region after curing (the same applies below).

Similarly, as shown in FIG. 2F, second fibers 44 (fibers similar to the first fibers 34) are introduced onto one thickness-wise surface of a first B resin layer (not shown) (a first B resin layer (not shown) containing a first B flame retardant component 42 and a first B resin component 43) formed from a first B resin composition, and a third resin layer (not shown) (a third resin layer (not shown) containing a third flame retardant component 46 and a third resin component 47) formed from a third resin composition is further disposed to produce a second SMC 48.

In the second SMC 48, the above-mentioned filter function restricts the movement of the first B flame retardant component 42 and the third flame retardant component 46 in the thickness direction, so that the first B flame retardant component 42 is localized on the other side in the thickness direction, and the third flame retardant component 46 is localized on the other side in the thickness direction.

In other words, the second SMC 48 has, in order toward one side in the thickness direction, a first B flame-retardant region 49' containing localized first B flame-retardant component 42 and first B resin component 43, a second fiber region 2' containing second fibers 44, first B resin component 43 and third resin component 47, and a third flame-retardant region 13' containing localized third flame-retardant component 46 and third resin component 47.

<<Third step>>
In the third step, a plurality of molding materials (SMC) are stacked and subjected to heat compression molding.

Specifically, as shown in FIG. 3A, the first SMC 39 and the second SMC 48 are stacked so that the surface on one side in the thickness direction of the first SMC 39 and the surface on the other side in the thickness direction of the second SMC 48 are in contact with each other, and then they are subjected to heat compression molding.

The conditions for heat compression molding are set appropriately depending on the purpose and application. In heat compression molding, the molding temperature is, for example, 100°C or higher, and, for example, 200°C or lower. The molding pressure is, for example, 0.1 MPa or higher, preferably 1 MPa or higher, more preferably 5 MPa or higher, and, for example, 20 MPa or lower, and preferably 15 MPa or lower.

As a result, the first A flame-retardant region 40' and the first B flame-retardant region 49' are thermally fused, and the first A resin composition containing the first A resin component 38 and the first B resin composition containing the first B resin component 43 are cured to form the first flame-retardant region 11. The second resin composition containing the second resin component 33 is cured to form the second flame-retardant region 12. The third resin composition containing the third resin component 47 is cured to form the third flame-retardant region 13. The second resin composition containing the second resin component 33 and the first A resin composition containing the first A resin component 38 are cured to form the first fiber region 1. The first B resin composition containing the first B resin component 43 and the third resin composition containing the third resin component 47 are cured to form the second fiber region 2.

As a result of the above, a laminate 100 is produced, which has, in order toward one side in the thickness direction, a second flame-retardant region 12, a first fiber region 1, a first flame-retardant region 11, a second fiber region 2, and a third flame-retardant region 13, as shown in FIG. 3B.

[Second flame-retardant region]
The second flame-retardant region 12 contains a cured product of a second resin composition that contains a second flame-retardant component 32 and a second resin component 33. That is, in the second flame-retardant region 12, the cured product of the second resin component 33 serves as a matrix, and the second flame-retardant component 32 is dispersed in the matrix.

The second flame retardant component 32 includes expanded graphite and/or a powdered flame retardant. The second flame retardant component 32 preferably includes expanded graphite and a powdered flame retardant from the viewpoint of flame retardancy. In other words, the second flame retardant region 12 includes expanded graphite and/or a powdered flame retardant, and preferably includes expanded graphite and a powdered flame retardant.

The thickness of the second flame-retardant region 12 is, for example, 0.1 mm or more, preferably 0.3 mm or more, and, for example, 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less.

[First fiber region]
The first fiber region 1 includes the first fibers 34, a cured product of the second resin component 33, and a cured product of the firstA resin component 38. That is, in the first fiber region 1, the cured product of the second resin component 33 and the cured product of the firstA resin component 38 form a matrix, and the first fibers 34 are oriented in the matrix so as to line up in a plane direction perpendicular to the thickness direction.

In the first fiber region 1, the mass per unit area of the first fibers 34 is 150 g/m ² or more and 1000 g/m ² or less.

If the mass per unit area of the first fiber 34 is equal to or greater than the lower limit, the filter function can be achieved.

On the other hand, if the mass per unit area of the first fiber 34 is less than the lower limit, the filter function cannot be achieved.

In addition, if the mass per unit area of the first fiber 34 is equal to or less than the above upper limit, the resin impregnation is excellent.

On the other hand, if the mass per unit area of the first fiber 34 exceeds the above upper limit, the resin impregnation property decreases.

In particular, from the viewpoint of ensuring the above-mentioned filter function, the first fibers 34 are glass fibers, and the mass per unit area is, for example, 200 g/m ² or more and 800 g/m ² or less.

The thickness of the first fiber region 1 is 0.1 mm or more, and, for example, 1.5 mm or less, preferably 1.0 mm or less.

If the thickness of the first fiber region 1 is equal to or greater than the lower limit, the filter function can be reliably achieved.

[First flame-retardant region]
The first flame-retardant region 11 includes a cured product of a 1A resin composition containing a 1A flame-retardant component 37 and a 1A resin component 38, and a cured product of a 1B resin composition containing a 1B flame-retardant component 42 and a 1B resin component 43. That is, in the first flame-retardant region 11, the cured product of the 1A resin component 38 and the cured product of the 1B resin component 43 form a matrix, and the 1A flame-retardant component 37 and the 1B flame-retardant component 42 are dispersed in the matrix.

The 1A resin composition and the 1B resin composition are the same. In the following description, the 1A resin composition and the 1B resin composition may be collectively referred to as the first resin composition. Also, the 1A flame retardant component 37 and the 1B flame retardant component 42 may be collectively referred to as the first flame retardant component. Also, the 1A resin component 38 and the 1B resin component 43 may be collectively referred to as the first resin component.

In other words, the first flame-retardant region 11 contains a cured product of a first resin composition that contains a first flame-retardant component and a first resin component.

The first flame retardant component contains a powdered flame retardant. In other words, the first flame retardant region 11 contains a powdered flame retardant.

If the first flame retardant component contains a powdered flame retardant, the flame retardancy can be improved.

In addition, from the viewpoint of further improving flame retardancy, the first flame retardant component preferably does not contain expandable graphite. In other words, the first flame retardant component preferably does not contain expandable graphite and is made of a powdered flame retardant. In other words, the first flame retardant region 11 preferably does not contain expandable graphite and contains a powdered flame retardant.

The thickness of the first flame-retardant region 11 is the sum of the thickness of the firstA flame-retardant region 40' and the thickness of the firstB flame-retardant region 49', and is, for example, 0.2 mm or more, preferably 0.6 mm or more, and, for example, 4.0 mm or less, preferably 3.0 mm or less, and more preferably 2.0 mm or less.

[Second fiber region]
The second fiber region 2 includes the second fibers 44, a cured product of the 1B resin component 43, and a cured product of the third resin component 47. That is, in the second fiber region 2, the cured product of the 1B resin component 43 and the cured product of the third resin component 47 form a matrix, and the second fibers 44 are oriented in the matrix so as to line up in a plane direction perpendicular to the thickness direction.

In the second fiber region 2, the mass per unit area of the second fibers 44 is 150 g/m ² or more and 1000 g/m ² or less.

If the mass per unit area of the second fiber 44 is equal to or greater than the lower limit, the filter function can be achieved.

On the other hand, if the mass per unit area of the second fiber 44 is less than the lower limit, the filter function cannot be achieved.

In addition, if the mass per unit area of the second fibers 44 is equal to or less than the above upper limit, the resin impregnation is excellent.

On the other hand, if the mass per unit area of the second fiber 44 exceeds the above upper limit, the resin impregnation property decreases.

In particular, from the viewpoint of ensuring the above-mentioned filter function, the second fibers 44 are glass fibers, and the mass per unit area is, for example, 200 g/m ² or more and 800 g/m ² or less.

The thickness of the second fiber region 2 is 0.1 mm or more, and, for example, 1.5 mm or less, preferably 1.0 mm or less.

If the thickness of the second fiber region 2 is equal to or greater than the above lower limit, the above filter function can be reliably achieved.

[Third flame retardant region]
The third flame-retardant region 13 contains a cured product of a third resin composition that contains a third flame-retardant component 46 and a third resin component 47. That is, in the third flame-retardant region 13, the cured product of the third resin component 47 serves as a matrix, and the third flame-retardant component 46 is dispersed in the matrix.

The third flame retardant component 46 includes expanded graphite and/or a powdered flame retardant. The third flame retardant component 46 preferably includes expanded graphite and a powdered flame retardant from the viewpoint of flame retardancy. In other words, the third flame retardant region 13 includes expanded graphite and/or a powdered flame retardant, and preferably includes expanded graphite and a powdered flame retardant.

That is, in the laminate 100, preferably, the first flame-retardant component (first flame-retardant region 11) is
Preferably, the second flame-retardant component 32 (second flame-retardant region 12) does not contain expanded graphite but contains a powdered flame retardant, and the third flame-retardant component 46 (third flame-retardant region 13) contains expanded graphite and a powdered flame retardant. This improves flame retardancy.

The thickness of the third flame-retardant region 13 is, for example, 0.1 mm or more, preferably 0.3 mm or more, and, for example, 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less.

According to the first embodiment, the first fiber region 1 and the second fiber region 2 restrict the movement of the first flame retardant component in the thickness direction. Therefore, a first flame retardant region 11 containing a localized first flame retardant component can be formed between the first fiber region 1 and the second fiber region 2. As a result, the flame retardancy can be improved.

The first fiber region 1 also restricts the movement of the second flame retardant component 32 in the thickness direction. This allows the formation of a second flame retardant region 12 that contains a localized second flame retardant component 32. The second fiber region 2 also restricts the movement of the third flame retardant component 46 in the thickness direction. This allows the formation of a third flame retardant region 13 that contains a localized third flame retardant component 46. As a result, the flame retardancy can be improved.

Selection of Flame Retardant Components in Laminates
In the laminate 100, preferably, in one flame retardant region adjacent to the fiber region in the thickness direction and the other flame retardant region, the one flame retardant region does not contain expanded graphite but contains a powdered flame retardant, and the other flame retardant region contains expanded graphite and a powdered flame retardant. According to such a configuration, a flame retardant region containing localized expanded graphite and a powdered flame retardant and a flame retardant region containing no expanded graphite but a localized powdered flame retardant are formed adjacent to each other. As a result, an expansion layer due to the action of the expandable graphite during combustion and a non-expansion layer that does not expand during combustion and maintains strength after combustion are arranged. Then, the expansion layer suppresses the temperature rise in a fire resistance test, and the non-expansion layer improves the remaining strength after combustion. As a result, the flame retardancy can be improved.

The fiber region is one selected from the group consisting of a first fiber region 1 and a second fiber region 2.

The flame-retardant region is one selected from the group consisting of a first flame-retardant region 11, a second flame-retardant region 12, and a third flame-retardant region 13.

Specifically, in the first flame-retardant region 11 and the second flame-retardant region 12 adjacent to the first fiber region 1 in the thickness direction, the first flame-retardant region 11 does not contain expandable graphite but contains a powdered flame retardant, and the second flame-retardant region 12 contains expandable graphite and a powdered flame retardant.

In addition, in the first flame-retardant region 11 and the third flame-retardant region 13 adjacent to the second fiber region 2 in the thickness direction, the first flame-retardant region 11 does not contain expandable graphite but contains a powdered flame retardant, and the third flame-retardant region 13 contains expandable graphite and a powdered flame retardant.

2. Second embodiment As shown in Fig. 4, the laminate 100 includes a second flame-retardant region 12, a first fiber region 1, a first flame-retardant region 11, a second fiber region 2, a third flame-retardant region 13, a third fiber region 3, and a fourth flame-retardant region 14, which are arranged in this order toward one side in the thickness direction.

In other words, the laminate 100 has a second flame-retardant region 12 on the other thickness-wise side of the first fiber region 1. The laminate 100 also has a third flame-retardant region 13, a third fiber region 3, and a fourth flame-retardant region 14, arranged in order toward one thickness-wise side, on one thickness-wise side of the second fiber region 2.

The method for manufacturing the laminate 100 includes a first step of preparing a resin composition, a second step of manufacturing a plurality of molding materials (SMC), and a third step of stacking the plurality of molding materials (SMC) and subjecting them to heat compression molding.

<<First Step>>
In the first step, a resin composition is prepared in the same manner as in the first embodiment.

<<Second step>>
In the second step, a plurality of molding materials (SMCs) are produced. Specifically, three molding materials (SMCs) are produced.

Specifically, as shown in FIG. 5A, the first SMC 39, the second SMC 48, and the third SMC 50 are manufactured in the same manner as in the first embodiment described above.

The first SMC 39 has, in order toward one side in the thickness direction, a second flame-retardant region 12' containing localized second flame-retardant component 32 and second resin component 33, a first fiber region 1' containing first fiber 34, second resin component 33 and first A resin component 38, and a first A flame-retardant region 40' containing localized first A flame-retardant component 37 and first A resin component 38.

The second SMC 48 has, in order toward one side in the thickness direction, a first B flame retardant region 49' containing localized first B flame retardant component 42 and first B resin component 43, a second fiber region 2' containing second fibers 44, first B resin component 43 and third A resin component 52, and a third A flame retardant region 53' containing localized third A flame retardant component 51 and third A resin component 52.

The third SMC 50 has, in order toward one side in the thickness direction, a third B flame retardant region 56' containing localized third B flame retardant component 54 and third B resin component 55, a third fiber region 3' containing third fibers 57 (fibers similar to the first fibers 34), third B resin component 55 and fourth resin component 58, and a fourth flame retardant region 14' containing localized fourth flame retardant component 59 and fourth resin component 58.

<<Third step>>
In the third step, a plurality of molding materials (SMC) are stacked and subjected to heat compression molding.

Specifically, as shown in FIG. 5B, the first SMC 39 and the second SMC 48 are stacked so that their surfaces on one side in the thickness direction are in contact with each other in the thickness direction, and the second SMC 48 and the third SMC 50 are stacked so that their surfaces on one side in the thickness direction are in contact with each other in the thickness direction, and then the stacked SMCs are subjected to heat compression molding.

As a result, the first A flame-retardant region 40' and the first B flame-retardant region 49' are thermally fused together, and the first A resin composition containing the first A resin component 38 and the first B resin composition containing the first B resin component 43 are cured to form the first flame-retardant region 11.

The third A flame-retardant region 53' and the third B flame-retardant region 56' are thermally fused together, and the third A resin composition containing the third A resin component 52 and the third B resin composition containing the third B resin component 55 are cured to form the third flame-retardant region 13.

The second resin composition containing the second resin component 33 cures to form the second flame-retardant region 12. The fourth resin composition containing the fourth resin component 58 cures to form the fourth flame-retardant region 14.

The second resin composition containing the second resin component 33 and the first A resin composition containing the first A resin component 38 are cured to form the first fiber region 1. The first B resin composition containing the first B resin component 43 and the third resin composition containing the third A resin component 52 are cured to form the second fiber region 2. The third B resin composition containing the third B resin component 55 and the fourth resin composition containing the fourth resin component 58 are cured to form the third fiber region 3.

By the above, a laminate 100 is manufactured which has, in order toward one side in the thickness direction, the second flame-retardant region 12, the first fiber region 1, the first flame-retardant region 11, the second fiber region 2, the third flame-retardant region 13, the third fiber region 3, and the fourth flame-retardant region 14.

[Second flame-retardant region]
The second flame-retardant region 12 is similar to that of the first embodiment. That is, the second flame-retardant component 32 in the second flame-retardant region 12 includes expanded graphite and/or a powdered flame retardant. The second flame-retardant component 32 preferably includes expanded graphite and a powdered flame retardant from the viewpoint of flame retardancy. That is, the second flame-retardant region 12 includes expanded graphite and/or a powdered flame retardant, and preferably includes expanded graphite and a powdered flame retardant.

[First fiber region]
The first fiber region 1 is similar to that in the first embodiment.

[First flame-retardant region]
The first flame-retardant region 11 is the same as that in the first embodiment. That is, the first flame-retardant region 11 includes a cured product of a first resin composition including a first flame-retardant component and a first resin component.

The first flame retardant component contains a powdered flame retardant, i.e., the first flame retardant region 11 contains a powdered flame retardant.

If the first flame retardant component contains a powdered flame retardant, the flame retardancy can be improved.

In addition, from the viewpoint of further improving flame retardancy, the first flame retardant component preferably does not contain expandable graphite. In other words, the first flame retardant component preferably does not contain expandable graphite and is made of a powdered flame retardant. In other words, the first flame retardant region 11 preferably does not contain expandable graphite and contains a powdered flame retardant.

[Second fiber region]
The second fiber region 2 is similar to that in the first embodiment.

[Third flame retardant region]
The third flame-retardant region 13 includes a cured product of a third-A resin composition including a third-A flame-retardant component 51 and a third-A resin component 52, and a cured product of a third-B resin composition including a third-B flame-retardant component 54 and a third-B resin component 55. That is, in the third flame-retardant region 13, the cured product of the third-A resin component 52 and the cured product of the third-B resin component 55 form a matrix, and the third-A flame-retardant component 51 and the third-B flame-retardant component 54 are dispersed in the matrix.

The third A resin composition and the third B resin composition are the same. In the second embodiment, the third A resin composition and the third B resin composition may be collectively referred to as the third resin composition. The third A flame retardant component 51 and the third B flame retardant component 54 may be collectively referred to as the third flame retardant component. The third A resin component 52 and the third B resin component 55 may be collectively referred to as the third resin component.

In other words, the third flame-retardant region 13 contains a cured product of a third resin composition that contains a third flame-retardant component and a third resin component.

The third flame retardant component includes a powdered flame retardant and/or expanded graphite. The third flame retardant component preferably includes expanded graphite and a powdered flame retardant from the viewpoint of flame retardancy. In other words, the third flame retardant region 13 includes expanded graphite and/or a powdered flame retardant, and preferably includes expanded graphite and a powdered flame retardant.

The thickness of the third flame-retardant region 13 is the sum of the thickness of the third A flame-retardant region 53' and the thickness of the third B flame-retardant region 56', and is, for example, 0.2 mm or more, preferably 0.6 mm or more, and, for example, 4.0 mm or less, preferably 3.0 mm or less, and more preferably 2.0 mm or less.

[Third fiber region]
The third fiber region 3 includes the third fibers 57, a cured product of the third B resin component 55, and a cured product of the fourth resin component 58. That is, in the third fiber region 3, the cured product of the third B resin component 55 and the cured product of the fourth resin component 58 form a matrix, and the third fibers 57 are oriented in the matrix so as to line up in a plane direction perpendicular to the thickness direction.

In the third fiber region 3, the mass per unit area of the third fibers 57 is 150 g/m ² or more and 1000 g/m ² or less.

If the mass per unit area of the third fiber 57 is equal to or greater than the lower limit, the filter function can be achieved.

In addition, if the mass per unit area of the third fibers 57 is equal to or less than the above upper limit, the resin impregnation is excellent.

In particular, from the viewpoint of ensuring the above-mentioned filter function, the third fibers 57 are glass fibers, and the mass per unit area is, for example, 200 g/m ² or more and 800 g/m ² or less.

The thickness of the third fiber region 3 is 0.1 mm or more, and, for example, 1.5 mm or less, preferably 1.0 mm or less.

If the thickness of the third fiber region 3 is equal to or greater than the above lower limit, the above filter function can be reliably achieved.

[Fourth flame-retardant region]
The fourth flame-retardant region 14 includes a cured product of a fourth resin composition including a fourth flame-retardant component 59 and a fourth resin component 58. That is, in the fourth flame-retardant region 14, the cured product of the fourth resin component 58 serves as a matrix, and the fourth flame-retardant component 59 is dispersed in the matrix.

The fourth flame retardant component 59 contains expanded graphite and/or a powdered flame retardant. From the viewpoint of flame retardancy, the fourth flame retardant component 59 preferably does not contain expanded graphite and is made of a powdered flame retardant. In other words, the fourth flame retardant region 14 contains expanded graphite and/or a powdered flame retardant, and preferably does not contain expanded graphite and contains a powdered flame retardant.

That is, in the laminate 100, preferably, the first flame-retardant component (first flame-retardant region 11) is
Preferably, the flame retardant does not contain expanded graphite but contains a powdered flame retardant, and the second flame retardant component 32 (second flame retardant region 12) contains expanded graphite and a powdered flame retardant, the third flame retardant component (third flame retardant region 13) contains expanded graphite and a powdered flame retardant, and the fourth flame retardant component 59 (fourth flame retardant region 14) does not contain expanded graphite but contains a powdered flame retardant. As a result, a flame retardant region containing localized expanded graphite and a powdered flame retardant and a flame retardant region containing no expanded graphite but a localized powdered flame retardant are formed adjacent to each other. As a result, an expansion layer due to the action of the expandable graphite during combustion and a non-expansion layer that does not expand during combustion and maintains strength after combustion are arranged. The expansion layer suppresses the temperature rise in the fire resistance test, and the non-expansion layer improves the remaining strength after combustion. As a result, the flame retardancy can be improved.

The thickness of the fourth flame-retardant region 14 is, for example, 0.1 mm or more, preferably 0.3 mm or more, and, for example, 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less.

According to the second embodiment, the first fiber region 1 and the second fiber region 2 limit the movement of the first flame retardant component in the thickness direction. Therefore, a first flame retardant region 11 containing a localized first flame retardant component can be formed between the first fiber region 1 and the second fiber region 2.

In addition, the second fiber region 2 and the third fiber region 3 restrict the movement of the third flame retardant component in the thickness direction. Therefore, a third flame retardant region 13 containing a localized third flame retardant component can be formed between the second fiber region 2 and the third fiber region 3. As a result, the flame retardancy can be improved.

The first fiber region 1 also restricts the movement of the second flame retardant component 32 in the thickness direction. This allows the formation of a second flame retardant region 12 that contains a localized second flame retardant component 32. The third fiber region 3 also restricts the movement of the fourth flame retardant component 59 in the thickness direction. This allows the formation of a fourth flame retardant region 14 that contains a localized fourth flame retardant component 59. As a result, the flame retardancy can be improved.

Selection of Flame Retardant Components in Laminates
In the laminate 100, preferably, in one flame retardant region adjacent to the fiber region in the thickness direction and the other flame retardant region, the one flame retardant region does not contain expanded graphite but contains a powdered flame retardant, and the other flame retardant region contains expanded graphite and a powdered flame retardant. According to such a configuration, a flame retardant region containing localized expanded graphite and a powdered flame retardant and a flame retardant region containing no expanded graphite but a localized powdered flame retardant are formed adjacent to each other. As a result, an expansion layer due to the action of the expandable graphite during combustion and a non-expansion layer that does not expand during combustion and maintains strength after combustion are arranged. Then, the expansion layer suppresses the temperature rise in a fire resistance test, and the non-expansion layer improves the remaining strength after combustion. As a result, the flame retardancy can be improved.

The fiber region is one selected from the group consisting of a first fiber region 1, a second fiber region 2, and a third fiber region 4.

The flame-retardant region is one selected from the group consisting of a first flame-retardant region 11, a second flame-retardant region 12, a third flame-retardant region 13, and a fourth flame-retardant region 14.

Specifically, in the first flame-retardant region 11 and the second flame-retardant region 12 adjacent to the first fiber region 1 in the thickness direction, the first flame-retardant region 11 does not contain expandable graphite but contains a powdered flame retardant, and the second flame-retardant region 12 contains expandable graphite and a powdered flame retardant.

In addition, in the first flame-retardant region 11 and the third flame-retardant region 13 adjacent to the second fiber region 2 in the thickness direction, the first flame-retardant region 11 does not contain expandable graphite but contains a powdered flame retardant, and the third flame-retardant region 13 contains expandable graphite and a powdered flame retardant.

In addition, in the fourth flame retardant region 14 and the third flame retardant region 13 adjacent to the third fiber region 3 in the thickness direction, the fourth flame retardant region 14 does not contain expanded graphite but contains a powdered flame retardant, and the third flame retardant region 13 contains expanded graphite and a powdered flame retardant.

3. Effects and Effects The laminate 100 includes a first flame-retardant region 11 containing a powdery flame retardant, sandwiched in the thickness direction between a first fiber region 1 containing a predetermined first fiber 34 and a second fiber region 2 containing a predetermined second fiber 44. This improves flame retardancy.

In more detail, as shown in FIG. 1, the laminate 100 has a first flame-retardant region 11 that contains localized flame-retardant components (first A flame-retardant component 37 and first B flame-retardant component 42), and therefore has excellent flame retardancy.

On the other hand, conventional SMC is manufactured using conventional reinforcing fibers 64 that do not include the above filter fibers.

Specifically, as shown in FIG. 6A, conventional SMCs are manufactured from a molding material that includes a resin composition containing a flame-retardant component 62 and a resin component 63, and conventional reinforcing fibers 64.

Conventional SMC does not contain filter fibers, so the flame retardant component 62 cannot be localized in the SMC, and the flame retardant component 62 is dispersed.

When two such SMCs are prepared, stacked, and heated and compressed, a conventional laminate 101 is obtained. However, as shown in FIG. 6B, in the conventional laminate 101, the flame-retardant component 62 is dispersed, and it is not possible to form an area containing localized flame-retardant component 62.

On the other hand, in the laminate 100, the first fiber region 1 and the second fiber region 2 contain a predetermined first fiber 34 and a predetermined second fiber 44, respectively, and the mass per unit area of the first fiber region 1 and the second fiber region 2 is adjusted to be within a predetermined range.

Therefore, the first fiber region 1 and the second fiber region 2 can suppress the movement of the flame-retardant components in the thickness direction.

More specifically, in the SMC, the flame retardant component can be localized on the other side in the thickness direction and on one side in the thickness direction. Specifically, as shown in FIG. 2E, in the first SMC 39, the second flame retardant component 32 can be localized on the other side in the thickness direction, and the first A flame retardant component 37 can be localized on one side in the thickness direction.

As shown in FIG. 3A, the first A flame-retardant region 40' containing the localized first A flame-retardant component 37 and the first B flame-retardant region 49' containing the localized first B flame-retardant component 42 are heat-sealed to form the first flame-retardant region 11, so that the localized flame-retardant components (the first A flame-retardant component 37 and the first B flame-retardant component 42) can be collected in the first flame-retardant region 11.

The first flame-retardant region 11 has excellent flame retardancy because it includes the first flame-retardant region 11 containing localized flame-retardant components (first A flame-retardant component 37 and first B flame-retardant component 42).

3. Modification 3-1. First Modification In the above description, the first SMC 39, the second SMC 48, and the third SMC 50 all contain filter fibers (specifically, the first fibers 34, the second fibers 44, and the third fibers 57) and the flame retardant component is localized, but in addition to such SMCs, it is also possible to add another SMC in which the flame retardant component is not localized.

The following description details an aspect of the first embodiment in which another SMC (the conventional SMC described above) is used.

<<First Step>>
In the first step, a resin composition is prepared in the same manner as in the first embodiment.

<<Second step>>
In the second step, a plurality of molding materials (SMCs) are produced. Specifically, three molding materials (SMCs) are produced.

Specifically, as shown in FIG. 7A, the first SMC 39 and the second SMC 48 are manufactured in the same manner as in the first embodiment described above.

The first SMC 39 has, in order toward one side in the thickness direction, a second flame-retardant region 12' containing localized second flame-retardant component 32 and second resin component 33, a first fiber region 1' containing first fiber 34, second resin component 33 and first A resin component 38, and a first A flame-retardant region 40' containing localized first A flame-retardant component 37 and first A resin component 38.

The second SMC 48 has, in order toward one side in the thickness direction, a first B flame-retardant region 49' containing localized first B flame-retardant component 42 and first B resin component 43, a second fiber region 2' containing second fibers 44, first B resin component 43 and third resin component 47, and a third flame-retardant region 13' containing localized third flame-retardant component 46 and third resin component 47.

Also, another SMC 61 is manufactured as shown in Figure 7B.

Other SMCs 61 do not contain filter fibers and are manufactured using conventional reinforcing fibers 64.

More specifically, the other SMC 61 is manufactured from a molding material that includes a resin composition containing a flame retardant component 62 and a resin component 63, and conventional reinforcing fibers 64.

Flame retardant component 62 is the same as 1A flame retardant component 37 and 1B flame retardant component 42.

Resin component 63 is the same as 1A resin component 38 and 1B resin component 43.

The conventional reinforcing fiber 64 is a fiber that does not provide the above-mentioned filter function, is a fiber bundle consisting of 151 or more single fibers, and is a chopped strand or cross-shaped reinforcing fiber. Specifically, the conventional reinforcing fiber 64 is, for example, a chopped strand or cross-shaped reinforcing fiber (preferably glass fiber), and is a fiber bundle consisting of 151 to 300 single fibers having a fiber diameter of 6 μm to 20 μm.

Other SMC61s are manufactured using known SMC impregnation machines.

The other SMC 61 does not contain filter fibers, so as shown in Figure 7B, flame-retardant components 62 and conventional reinforcing fibers 64 are dispersed in the resin component 63.

<<Third step>>
In the third step, a plurality of molding materials (SMC) are stacked and subjected to heat compression molding.

Specifically, as shown in FIG. 7C, the other SMC 61 is stacked and heated and compressed so that the surface on one side of the thickness direction of the first SMC 39 is in contact with the surface on the other side of the thickness direction of the first SMC 39, and the surface on one side of the thickness direction of the first SMC 39 is in contact with the surface on the other side of the thickness direction of the second SMC 48.

As a result, the second flame-retardant region 12' and the surface on one side of the thickness direction of the other SMC 61 are thermally fused, and the first A flame-retardant region 40' and the first B flame-retardant region 49' are thermally fused.

By the above steps, a laminate 100 is produced that has the second flame-retardant region 12, the first fiber region 1, the first flame-retardant region 11, the second fiber region 2, and the third flame-retardant region 13 in that order toward one side in the thickness direction.

The second flame-retardant region 12 includes a cured product of a resin composition containing a flame-retardant component 62 and a resin component 63, a cured product of a second resin composition containing a second flame-retardant component 32 and a second resin component 33, and conventional reinforcing fibers 64 (preferably chopped strand or cross reinforcing fibers).

In the second flame-retardant region 12, the cured resin component 63 and the cured second resin component 33 form a matrix, and the flame-retardant components (the second flame-retardant component 32 and the flame-retardant component 62) and conventional reinforcing fibers 64 are dispersed in the matrix.

The second flame retardant component 32 and the flame retardant component 62 preferably do not contain expandable graphite and are made of a powdered flame retardant from the standpoint of flame retardancy. In other words, the second flame retardant region 12 preferably does not contain expandable graphite and contains a powdered flame retardant.

The first fiber region 1 is the same as in the first embodiment above.

The first flame-retardant region 11 is similar to the first embodiment described above. That is, the first flame-retardant component in the first flame-retardant region 11 preferably does not include expandable graphite, but includes a powdered flame retardant. That is, the first flame-retardant region 11 preferably does not include expandable graphite, but includes a powdered flame retardant.

The second fiber region 2 is the same as in the first embodiment.

The third flame-retardant region 13 is the same as in the first embodiment. That is, the third flame-retardant component 46 in the third flame-retardant region 13 includes expanded graphite and/or a powdered flame retardant. The third flame-retardant component 46 preferably includes expanded graphite and a powdered flame retardant from the viewpoint of flame retardancy. That is, the third flame-retardant region 13 includes expanded graphite and/or a powdered flame retardant, and preferably includes expanded graphite and a powdered flame retardant.

In other words, in the laminate 100, preferably, the first flame-retardant region 11 does not contain expanded graphite but contains a powdered flame retardant, the second flame-retardant region 12 contains expanded graphite and a powdered flame retardant, and the third flame-retardant region 13 contains expanded graphite and a powdered flame retardant. This improves flame retardancy.

In addition, in the laminate 100, the second flame-retardant region 12 preferably contains reinforcing fibers in the form of chopped strands or crosses. This improves the mechanical properties.

As described above, the other SMC 61 does not contain filter fibers and is manufactured using conventional reinforcing fibers 64, so that the flame retardant component 62 and conventional reinforcing fibers 64 are dispersed in the resin component 63.

On the other hand, other SMCs 61, even if they contain filter fibers, can disperse flame retardant components 62 by adjusting the mass per unit area.

In the above description, after a plurality of molding materials (SMC) are produced in the second step, these molding materials (SMC) are layered and heated and compressed in the third step, but as shown in FIG. 8A , the second step may not be performed, and the second resin layer 31, the first fibers 34, the firstA resin layer 36, the second fibers 44, and the third resin layer 45 may be layered in order toward one side in the thickness direction, and heated and compressed.

This produces a laminate 100 having, in order toward one side in the thickness direction, the second flame-retardant region 12, the first fiber region 1, the first flame-retardant region 11, the second fiber region 2, and the third flame-retardant region 13, as shown in FIG. 8B.

Preferably, as shown in FIG. 8C, another SMC 61, the first fiber 34, the first A resin layer 36, the second fiber 44, and the third resin layer 45 are stacked in order toward one side in the thickness direction and then subjected to heat compression molding.

3-3. Third Modification In the first embodiment, two SMCs are produced in the second step, and then heated and compressed to produce a laminate 100 having three flame-retardant regions and two fiber regions in the third step.

In the second embodiment, three SMCs are produced in the second step, and then heated and compressed in the third step to produce a laminate 100 having four flame-retardant regions and three fiber regions.

On the other hand, the number of flame-retardant regions and fiber regions in the laminate 100 is not limited to this. For example, four SMCs can be produced in the second step, and these can be heated and compressed to produce a laminate 100 having five flame-retardant regions and four fiber regions in the third step.

In other words, in the second step, N SMCs are produced, and in the third step, these are heated and compressed to produce a laminate 100 having N+1 flame-retardant regions and N fiber regions.

3-4. Fourth Modification The SMC (specifically, the first SMC 39, the second SMC 48, and the third SMC 50) has two flame-retardant regions, but may have only one flame-retardant region. Below, a laminate 100 obtained using the first SMC 39 and the second SMC 48 each having one flame-retardant region will be described in detail as an example.

As shown in FIG. 9A, the first SMC 39 has a first fiber region 1' including a first fiber 34 and a first A resin component 38, and a first A flame retardant region 40' including localized first A flame retardant components 37 and a first A resin component 38, arranged in sequence toward one side in the thickness direction.

The second SMC 48 also includes a second fiber region 2' including a second fiber 44 and a third resin component 47, and a third flame-retardant region 13' including a localized third flame-retardant component 46 and a third resin component 47, arranged in sequence toward one side in the thickness direction.

Then, preferably, as shown in FIG. 9B, another SMC 61, a first SMC 39, and a second SMC 48 are stacked in order toward one side in the thickness direction and heat-compression molded. This produces a laminate 100 having a second flame-retardant region 12, a first fiber region 1, a first flame-retardant region 11, a second fiber region 2, and a third flame-retardant region 13 in order toward one side in the thickness direction, as shown in FIG. 9C.

The present invention will be described in more detail below with reference to examples. However, the following description is one embodiment of the present invention, and the present invention is not limited to these descriptions.

Specific numerical values of the compounding ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit (numerical value defined as "equal to or less than") or lower limit (numerical value defined as "equal to or more than" or "exceeding") of the corresponding compounding ratio (content ratio), physical property value, parameter, etc. described in the above "Description of the Invention." In addition, unless otherwise specified in the following description, "parts" and "%" are based on mass.

<Ingredient details>
Polystyrene solution: polystyrene (number average molecular weight approximately 110,000) solution with styrene content of 60% by mass Phosphorus-based flame retardant: aluminum trisdiethylphosphinate, average particle size 30 μm
Melamine-based flame retardant: melamine cyanurate, average particle size 15 μm
Expanded graphite: average particle size 75 μm
Aluminum hydroxide: average particle size 8 μm
Fiber 1: Glass fiber felt (heat-resistant glass felt), single fiber having a fiber diameter of 12 μm, product name "Glass needle mat MNA-300-1000-30m", basis weight 300 g/m ² , manufactured by Nippon Glass Fiber Industrial Co., Ltd. Fiber 2: Glass fiber felt (heat-resistant glass felt), single fiber having a fiber diameter of 12 μm, product name "Glass needle mat MNA-500-1000-30m", basis weight 500 g/m ² , manufactured by Nippon Glass Fiber Industrial Co., Ltd. Fiber 3: Glass fiber felt (heat-resistant glass felt), single fiber having a fiber diameter of 12 μm, product name "Glass needle mat MNA-600-1000-30m", basis weight 600 g/m ² Fiber 4: Glass cloth, a glass cloth woven from a fiber bundle of 650 single fibers having a fiber diameter of 10 μm and subjected to a coupling treatment, product name "M205K 104H", basis weight 200 g/m ² , manufactured by Unitika Ltd. Fiber 5: 1-inch chopped glass (chopped strand glass fiber), a fiber bundle of 100 single fibers having a fiber diameter of 10 μm, length 25 mm
Fiber 6: 1 inch chopped glass (chopped strand glass fiber), fiber bundle consisting of 250 single fibers having a fiber diameter of 12 μm, length 25 mm

<Preparation of Unsaturated Polyester Resin>
Preparation Example 1
A flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser and a stirrer was charged with 3.3 moles of isophthalic acid and 10.5 moles of propylene glycol. Then, under a nitrogen gas atmosphere, the mixture was subjected to a polycondensation reaction at 200°C to 210°C while stirring. Then, the mixture was cooled to 150°C when the acid value of the reaction product reached 20 mgKOH/g. Next, 6.7 moles of maleic anhydride were charged and reacted again at 210°C to 220°C. An unsaturated polyester with an acid value of 27.5 mgKOH/g was obtained. To 100 parts by mass of this unsaturated polyester, 0.01 parts by mass of hydroquinone and 66.7 parts by mass of styrene were added as a polymerization inhibitor, and these were mixed uniformly. As a result, an unsaturated polyester resin (styrene content 40% by mass) was obtained.

<Production of Laminate>
Examples 4, 5, and 11 to 13 (Laminate of the First Embodiment (FIG. 1))
[First step]
According to the formulations shown in Table 1, the components were mixed to prepare resin compositions of Production Examples 1 to 3.

[Second step]
The formulation of each component was as shown in Table 2. Furthermore, 1.0 part by mass of magnesium oxide was added to each resin composition as a thickener.

A second resin composition was applied to one surface of one of the separate films in the thickness direction to form a second resin layer, and the first fibers were introduced to the surface of the second resin layer in the thickness direction.

Next, the 1A resin composition was applied to one surface in the thickness direction of the other separate film to form the 1A resin layer.

Next, the surface of one side in the thickness direction of the second resin layer into which the first fibers were introduced was overlapped with the surface of the first A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the first SMC.

Separately, a first B resin composition was applied to one surface in the thickness direction of one separate film to form a first B resin layer, and second fibers were introduced to one surface in the thickness direction of the first B resin layer.

Next, a third resin composition was applied to one surface in the thickness direction of the other separate film to form a third resin layer.

Next, the surface of one side in the thickness direction of the first B resin layer into which the second fibers were introduced was overlapped with the surface of the third resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the second SMC.

[Third step]
The first SMC and the second SMC were stacked so that the surface on one side in the thickness direction of the first SMC and the surface on the other side in the thickness direction of the second SMC were in contact with each other, and the weights of the layers were adjusted so that each layer had a predetermined thickness, followed by heat compression molding to obtain a laminate.

Examples 6 to 9 and Example 12 (Laminate of the Second Embodiment (FIG. 3))
[First step]
According to the formulations shown in Table 1, the components were mixed to prepare resin compositions of Production Examples 1 and 2.

[Second step]
The formulation of each component was as shown in Table 3. Furthermore, 1.0 part by mass of magnesium oxide was added as a thickener to each resin composition.

A second resin composition was applied to one surface of one of the separate films in the thickness direction to form a second resin layer, and the first fibers were introduced to the surface of the second resin layer in the thickness direction.

Next, the 1A resin composition was applied to one surface in the thickness direction of the other separate film to form the 1A resin layer.

Next, the surface of one side in the thickness direction of the second resin layer into which the first fibers were introduced was overlapped with the surface of the first A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the first SMC.

Separately, a first B resin composition was applied to one surface in the thickness direction of one separate film to form a first B resin layer, and second fibers were introduced to one surface in the thickness direction of the first B resin layer.

Next, the 3A resin composition was applied to one surface in the thickness direction of the other separate film to form a 3A resin layer.

Next, the surface of one side in the thickness direction of the first B resin layer into which the second fibers were introduced was overlapped with the surface of the third A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the second SMC.

Separately, a third B resin composition was applied to one surface in the thickness direction of one separate film to form a third B resin layer, and third fibers were introduced to one surface in the thickness direction of the third B resin layer.

Next, a fourth resin composition was applied to one surface in the thickness direction of the other separate film to form a fourth resin layer.

Next, one side of the thickness direction of the third B resin layer into which the third fibers were introduced was overlapped with the surface of the fourth resin layer, and then pressure was applied from the outside. Next, it was aged at 40°C for 48 hours, thereby producing the third SMC.

[Third step]
The first SMC and the second SMC were stacked so that the surface on one side of the thickness direction of the first SMC contacted the surface on the other side of the thickness direction of the second SMC, and the surface on one side of the thickness direction of the second SMC contacted the surface on the other side of the thickness direction of the third SMC, and the weights of the layers were adjusted to a predetermined thickness, and the layers were heated and compressed. Thus, a laminate was obtained. Note that Example 6 and Example 7 are the same except that they are upside down.

Examples 1 to 3 (Fourth Modification (FIG. 9B))
[First step]
According to the formulations shown in Table 1, the components were mixed to prepare resin compositions of Production Examples 1 and 2.

[Second step]
The formulation of each component was as shown in Table 4. Furthermore, 1.0 part by mass of magnesium oxide was added as a thickener to each resin composition.

A first resin composition was applied to one surface of the separate film in the thickness direction to form a first resin layer, and a first fiber was introduced to the other surface of the first resin layer in the thickness direction, after which pressure was applied from the outside. The mixture was then aged at 40°C for 48 hours, thereby producing a first SMC.

A third resin composition was applied to one surface of the separation film in the thickness direction to form a third resin layer, and second fibers were introduced to the other surface of the third resin layer in the thickness direction, after which pressure was applied from the outside. The mixture was then aged at 40°C for 48 hours, thereby producing a second SMC.

Other SMCs were produced from other resin compositions using the SMC impregnation machine.

[Third step]
These were stacked so that the other SMC and the surface on the other side in the thickness direction of the first SMC were in contact with each other, and the surface on one side in the thickness direction of the first SMC and the surface on the other side in the thickness direction of the second SMC were in contact with each other, and the weights of each layer were adjusted to a predetermined thickness, followed by heat compression molding. Thus, a laminate was obtained.

Example 10 (Third variant (laminate with five flame-retardant regions and four fibrous regions))
[First step]
According to the formulations shown in Table 1, the components were mixed to prepare resin compositions of Production Examples 1 and 2.

[Second step]
The formulation of each component was as shown in Table 5. Furthermore, 1.0 part by mass of magnesium oxide was added as a thickener to each resin composition.

A second resin composition was applied to one surface of one of the separate films in the thickness direction to form a second resin layer, and the first fibers were introduced to the surface of the second resin layer in the thickness direction.

Next, the 1A resin composition was applied to one surface in the thickness direction of the other separate film to form the 1A resin layer.

Next, the surface of one side in the thickness direction of the second resin layer into which the first fibers were introduced was overlapped with the surface of the first A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the first SMC.

Separately, a first B resin composition was applied to one surface in the thickness direction of one separate film to form a first B resin layer, and second fibers were introduced to one surface in the thickness direction of the first B resin layer.

Next, the 3A resin composition was applied to one surface in the thickness direction of the other separate film to form a 3A resin layer.

Next, the surface of one side in the thickness direction of the first B resin layer into which the second fibers were introduced was overlapped with the surface of the third A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the second SMC.

Separately, a third B resin composition was applied to one surface in the thickness direction of one separate film to form a third B resin layer, and third fibers were introduced to one surface in the thickness direction of the third B resin layer.

Next, the 4A resin composition was applied to one surface in the thickness direction of the other separate film to form the 4A resin layer.

Next, one side of the thickness direction of the third B resin layer into which the third fiber had been introduced was overlapped with the surface of the fourth A resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the third SMC.

Separately, a 4B resin composition was applied to one surface in the thickness direction of one separate film to form a 4B resin layer, and 4 fibers were introduced to one surface in the thickness direction of the 4B resin layer.

Next, the fifth resin composition was applied to one surface in the thickness direction of the other separate film to form a fifth resin layer.

Next, the surface of one side in the thickness direction of the fourth B resin layer into which the fourth fiber had been introduced was overlapped with the surface of the fifth resin layer, and then pressure was applied from the outside. Next, the mixture was aged at 40°C for 48 hours, thereby producing the fourth SMC.

[Third step]
These were stacked so that the surface of the first SMC on one side in the thickness direction was in contact with the surface of the second SMC on the other side in the thickness direction, the surface of the second SMC on one side in the thickness direction was in contact with the surface of the third SMC on the other side in the thickness direction, and the surface of the third SMC on one side in the thickness direction was in contact with the surface of the fourth SMC on the other side in the thickness direction, and the weights of each layer were adjusted to a predetermined thickness, followed by heat compression molding. This produced a laminate.

Comparative Example 1 (other SMC/other SMC/first fiber region/first flame retardant region)
[First step]
According to the formulations shown in Table 1, the components were mixed to prepare resin compositions of Production Examples 1 and 2.

[Second step]
The formulation of each component was as shown in Table 6. Furthermore, 1.0 part by mass of magnesium oxide was added as a thickener to each resin composition.

Using an SMC impregnation machine, a first other SMC was produced from the first other resin composition, and a second other SMC was produced from the second other resin composition.

[Third step]
The first other SMC, the second other SMC, the first fiber, and the first resin layer were stacked in order toward one side in the thickness direction, and the weights of the layers were adjusted so that each layer had a predetermined thickness, and the layers were subjected to heat compression molding to obtain a laminate.

Comparative Examples 2, 3 and 5 (Other SMC/Other SMC)
A laminate was produced in the same manner as in Example 4. However, the compounding formulation of each component was in accordance with Table 7. In addition, in Example 4, the Nth resin layer, the Nth resin composition, the Nth SMC, and the Nth fiber were read as the Nth other resin layer, the Nth other resin composition, the Nth other SMC, and the Nth other fiber.

Comparative Example 4 and Comparative Example 6 (Other SMC/Other SMC/Other SMC/Other SMC)
A laminate was produced in the same manner as in Example 6. However, the compounding recipe of each component was in accordance with Table 8. In addition, in Example 6, the Nth resin layer, the Nth resin composition, the Nth SMC, and the Nth fiber were replaced with the Nth other resin layer, the Nth other resin composition, the Nth other SMC, and the Nth other fiber.

<Evaluation>
<Flame Retardancy Test>
(Fire resistance test)
A test piece (150 mm x 150 mm) was cut from the laminate of each Example and Comparative Example. Next, a gas burner was used to adjust the length of the inner flame of the burner to about 50 mm and the temperature of the tip of the inner flame to about 1000 ° C. Furthermore, the center of the 150 mm x 150 mm test piece was fixed so that it was in a vertical position 40 mm from the tip of the burner. Furthermore, it was fixed so that the center of the other side of the thickness direction of the test piece (corresponding to the other side of the thickness direction of the laminate) could be measured with an infrared thermometer. The burner was ignited, and while measuring the temperature of the test piece, a flame was emitted on one side of the thickness direction of the test piece (corresponding to the one side of the thickness direction of the laminate), and the flame was stopped after 5 minutes. The time when the temperature of the back side of the test piece exceeded 400 ° C. when the flame was emitted and the maximum back side temperature of the test piece were measured. The results are shown in Tables 1 to 8.

(Residual strength after burning)
After the fire resistance test, the specimens were cooled to room temperature, and a 10 mm diameter round bar was lowered at 1 mm/min to the center of the specimen until it broke, and the maximum load was measured. The results are shown in Tables 1 to 8.

Reference Signs List 1 First fiber region 2 Second fiber region 3 Third fiber region 11 First flame-retardant region 12 Second flame-retardant region 13 Third flame-retardant region 14 Fourth flame-retardant region 32 Second flame-retardant component 34 First fibers 37, 42 First flame-retardant component 44 Second fibers 46 Third flame-retardant component 57 Third fibers 59 Fourth flame-retardant component

Claims (14)

a first fiber region including first fibers;
a first flame-retardant region including a cured product of a first resin composition including a first flame-retardant component;
a second fiber region including a second fiber and a second fiber region including a second fiber,
The first fibers and the second fibers are single fibers and/or fiber bundles each including 1 to 150 single fibers having a fiber diameter of 6 μm or more and 20 μm or less,
In the first fiber region, a mass per unit area of the first fibers is 150 g/m ² or more and 1000 g/m ² or less,
In the second fiber region, a mass per unit area of the second fibers is 150 g/m ² or more and 1000 g/m ² or less,
The first flame retardant component comprises a powdered flame retardant. A second flame-retardant region is provided on the other thickness direction side of the first fiber region,
The second flame-retardant region includes a cured product of a second resin composition including a second flame-retardant component,
The second flame retardant component includes expandable graphite and/or a powdered flame retardant;
A third flame-retardant region is provided on one side of the second fiber region in a thickness direction,
the third flame-retardant region includes a cured product of a third resin composition including a third flame-retardant component;
The laminate of claim 1 , wherein the third flame retardant component comprises expandable graphite and/or a powdered flame retardant. In one flame-retardant region and another flame-retardant region adjacent to the fiber region in the thickness direction,
The one flame-retardant region does not contain expandable graphite and contains a powdered flame retardant,
the other flame retardant region includes expandable graphite and a powdered flame retardant;
the fiber region is one selected from the group consisting of the first fiber region and the second fiber region,
The laminate of claim 2 , wherein the flame retardant region is one selected from the group consisting of the first flame retardant region, the second flame retardant region, and the third flame retardant region.
The first flame retardant component does not contain expandable graphite,
The second flame retardant component includes expandable graphite and a powdered flame retardant,
3. The laminate of claim 2, wherein the third flame retardant component comprises expandable graphite and a powdered flame retardant. The laminate according to claim 2, wherein the second flame-retardant region is a fiber bundle consisting of 151 or more single fibers, and includes chopped strand or cross reinforcing fibers. The first flame retardant component does not contain expandable graphite,
The second flame retardant component does not include expandable graphite and includes a powdered flame retardant;
6. The laminate of claim 5, wherein the third flame retardant component comprises expandable graphite and a powdered flame retardant. a third flame-retardant region and a third fiber region including third fibers are provided in this order toward one side in the thickness direction of the second fiber region,
the third flame-retardant region includes a cured product of a third resin composition including a third flame-retardant component;
The third flame retardant component includes expandable graphite and/or a powdered flame retardant,
The third fibers are single fibers and/or fiber bundles each including 1 to 150 single fibers having a fiber diameter of 6 μm or more and 20 μm or less,
The laminate according to claim 1 , wherein in the third fiber region, a mass per unit area of the third fibers is 150 g/m ² or more and 1000 g/m ² or less. A second flame-retardant region is provided on the other thickness direction side of the first fiber region,
The second flame-retardant region includes a cured product of a second resin composition including a second flame-retardant component,
The second flame retardant component includes expandable graphite and/or a powdered flame retardant;
A fourth flame-retardant region is provided on one side of the third fiber region in a thickness direction,
the fourth flame-retardant region includes a cured product of a fourth resin composition including a fourth flame-retardant component;
8. The laminate of claim 7, wherein the fourth flame retardant component comprises expandable graphite and/or a powdered flame retardant. In one flame-retardant region and another flame-retardant region adjacent to the fiber region in the thickness direction,
The one flame-retardant region does not contain expandable graphite and contains a powdered flame retardant,
the other flame retardant region includes expandable graphite and a powdered flame retardant;
the fiber region is one selected from the group consisting of the first fiber region, the second fiber region, and the third fiber region;
9. The laminate of claim 8, wherein the flame retardant region is one selected from the group consisting of the first flame retardant region, the second flame retardant region, the third flame retardant region, and a fourth flame retardant region. The first flame retardant component does not contain expandable graphite,
The second flame retardant component includes expandable graphite and a powdered flame retardant,
The third flame retardant component includes expandable graphite and a powdered flame retardant,
9. The laminate of claim 8, wherein the fourth flame retardant component is free of expandable graphite and includes a powdered flame retardant. the first fiber is a glass fiber;
In the first fiber region, a mass per unit area of the first fibers is 200 g/m ² or more and 800 g/m ² or less,
the second fibers are glass fibers;
The laminate according to any one of claims 1 to 6, wherein in the second fiber region, the mass per unit area of the second fibers is 200 g/ ^m2 or more and 800 g/ ^m2 or less. the first fiber is a glass fiber;
In the first fiber region, a mass per unit area of the first fibers is 200 g/m ² or more and 800 g/m ² or less,
the second fibers are glass fibers;
In the second fiber region, a mass per unit area of the second fibers is 200 g/m ² or more and 800 g/m ² or less,
the third fiber is a glass fiber;
The laminate according to any one of claims 7 to 10, wherein in the third fiber region, the mass per unit area of the third fibers is 200 g/ ^m2 or more and 800 g/ ^m2 or less. The laminate according to claim 11, wherein the average particle size of the powdered flame retardant is 10 μm or more and 200 μm or less. The laminate according to claim 12, wherein the average particle size of the powdered flame retardant is 10 μm or more and 200 μm or less.