WO2025052909A1 - Fiber material, curable material, cured product, and laminate - Google Patents

Abstract

[Problem] To provide a fiber material or the like which is excellent in handleability and contributes to improvement of strength of a structure to be obtained. [Solution] According to one embodiment of the present invention, a matte-shaped fiber material containing a nonwoven fabric is provided. On a first surface of the fiber material in the fiber material, there is a notch extending from the first surface to the inside of the fiber material. The fiber material has a needle punch mark that penetrates the fiber material.

Description

Fiber materials, curable materials, cured products and laminates

The present invention relates to a fiber material, a curable material, a cured product, and a laminate.

Conventionally, a method of using a core material to obtain a structure containing fiber reinforced plastics (FRP; Fiber Reinforced Plastics) is known (see, for example, Patent Document 1). The use of such a core material can contribute to weight reduction when obtaining a structure.

JP 2008-230235 A

Incidentally, it is important for the core material described above to be both easy to handle and have the ability to contribute to improving the strength of the resulting structure.

In consideration of the above circumstances, the present invention aims to provide a fiber material etc. that is easy to handle and contributes to improving the strength of the resulting structure.

According to one aspect of the present invention, a mat-shaped fiber material including a nonwoven fabric is provided. A first surface of the fiber material has a notch extending from the first surface to the inside of the fiber material. The fiber material has needle punch marks penetrating the fiber material.

The above aspect provides a fiber material that is easy to handle and contributes to improving the strength of the resulting structure.

1 is a cross-sectional view showing a schematic diagram of a fiber material 10A according to an embodiment of the present invention. 1 is a plan view showing a schematic diagram of a fiber material 10A according to an embodiment of the present invention; 1 is a cross-sectional view showing a laminate 100 to which a fiber material 10A is applied. FIG. 13 is a plan view showing a modified example of the fiber material. 1 is a photograph showing a fiber material of an example. 1 is a photograph showing a comparison of fiber materials of an example and a comparative example.

Below, an embodiment of the present invention will be described. Note that the various characteristic features shown in the following embodiment can be combined with each other. In this specification, "(meth)acrylate" refers to a concept that includes both "acrylate" and "methacrylate". In this specification, "(meth)acrylic acid" refers to a concept that includes both "acrylic acid" and "methacrylic acid". In this specification, "~" refers to the above to the following unless otherwise specified.

[Textile materials]
First, the fiber material of the present embodiment will be described.

The fiber material of this embodiment is as follows.
A mat-like fiber material including a nonwoven fabric,
a first surface of the fibrous material has a notch extending from the first surface to an interior of the fibrous material;
The textile material has needle punch marks penetrating the textile material.

The fiber material of this embodiment is, for example, a mat-like fiber material that is impregnated with a curable composition described below. Figure 1 is a cross-sectional view that shows a schematic of the fiber material 10A of this embodiment.

Furthermore, the fiber material 10A of this embodiment is characterized in that the first surface of the fiber material 10A (the surface shown at the top in FIG. 1) has a notch 3 that extends from the first surface to the inside of the fiber material 10A. Furthermore, the fiber material 10A of this embodiment has needle punch marks 2 that penetrate the fiber material 10A.

The thickness of the fiber material 10A may be appropriately set, but from the viewpoint of further improving handleability, the average thickness _T0 of the fiber material 10A may be in the range of 0.5 to 10 mm, may be in the range of 0.7 to 8 mm, or may be in the range of 1 to 7 mm.

Furthermore, the fiber material 10A has the above-mentioned notches 3, and the ratio _T1 / _T0 of the average depth _T1 of the notches ₃ to the average thickness T0 of the fiber material 10A may be in the range of 0.1 to 0.99, 0.3 to 0.97, or 0.5 to 0.95. By setting the ratio in such a range, it becomes easier to obtain a balance between the handleability and mechanical strength of the fiber material 10A.

FIG. 2 is a plan view showing a schematic diagram of the fiber material 10A of this embodiment. This diagram shows the fiber material 10A observed from the first surface. As described above, the fiber material 10A includes needle punch marks 2 and notches 3. In the fiber material 10A shown in FIG. 2, multiple notches 3 are present on the first surface and are arranged so as to be approximately parallel. However, as will be described later, the arrangement of the notches 3 is not limited to that shown in FIG. 2.

In the fiber material 10A shown in FIG. 2, the multiple needle punch marks 2 are arranged at equal intervals, but this is not limited thereto, and the needle punch marks 2 may be arranged at random intervals. Note that the needle punch marks 2 result from the needle punching process performed on the nonwoven fabric 1, and the nonwoven fabric used may be one of the following:

In other words, the nonwoven fabric 1 used in this embodiment has needle punch marks 2 and is also known as a "needle punched nonwoven fabric." The fibers that make up this nonwoven fabric 1 may be polyolefin resins such as polypropylene (PP) fibers; polyester fibers such as polyethylene terephthalate (PET); or synthetic resins such as nylon fibers. The fibers that make up the nonwoven fabric 1 may also be any type of fiber, such as natural fibers such as cotton or hemp, or carbon fibers.

The number (density) of needle punch marks 2 in the nonwoven fabric 1 can be set as appropriate. As an example, for a 10 cm x 10 cm nonwoven fabric 1, it is preferable to use a nonwoven fabric 1 having 10 to 500 needle punch marks 2, more preferably a nonwoven fabric 1 having 20 to 300 needle punch marks 2, and even more preferably a nonwoven fabric 1 having 50 to 200 needle punch marks 2. By setting the number within such a range, the fiber material is more likely to exhibit better mechanical properties.

The shape of the needle punch marks 2 can be set as appropriate, but is typically circular. When the needle punch marks 2 are circular, their diameter is preferably in the range of 0.1 mm to 5 mm, more preferably in the range of 0.2 mm to 3 mm, and even more preferably in the range of 0.3 mm to 2 mm. Setting the diameter in such a range makes it easier for the fiber material to exhibit better mechanical properties. Note that the diameter here is the average value for all the needle punch marks 2 present throughout the nonwoven fabric 1.

Furthermore, although a specific embodiment is not shown in Figures 1 and 2, the fiber material 10A may contain microballoons therein. By containing microballoons therein in this way, the fiber material 10A can contribute to reducing the weight of the fiber material 10A.

These microballoons may be organic or inorganic. An example of an organic microballoon is a plastic microballoon. Examples of plastic microballoons include homopolymers of phenol, urea, styrene, saran, vinyl chloride, acrylonitrile, etc., or copolymers of two or more of these. Examples of inorganic microballoons include glass balloons, silica balloons, shirasu balloons, carbon balloons, alumina balloons, and zirconia balloons.

Such microballoons may be surface-treated with an organic or inorganic surface treatment agent. Examples of organic surface treatment agents include fatty acids, resin acids, and fatty acid esters. Examples of inorganic surface treatment agents include calcium carbonate, barium sulfate, talc, titanium oxide, titanium, clay, and silica.

The average particle size of the microballoons is not particularly limited, and for example, the lower limit of the average particle size may be 5 μm or more, 10 μm or more, 20 μm or more, 25 μm or more, or 30 μm or more. The upper limit of the average particle size of the microballoons may be, for example, 300 μm or less, 100 μm or less, 80 μm or less, 50 μm or less, or 40 μm or less.

When the fiber material 10A contains microballoons, the content of the microballoons in the entire fiber material 10A can be set appropriately. The volumetric percentage of the microballoons in the entire fiber material 10A is, for example, 15 volume % or more and 70 volume % or less, preferably 25 volume % or more and 65 volume % or less, and more preferably 30 volume % or more and 60 volume % or less. By setting it in such a range, it becomes easier to balance the handleability and lightness of the fiber material.

In addition, since the fiber material 10A may contain microballoons in this way, the porosity of the fiber material 10A may be set to an appropriate range. That is, the range of the porosity of the fiber material 10A is, for example, 15 vol.% to 70 vol.%, preferably 25 vol.% to 65 vol.%, and more preferably 30 vol.% to 60 vol.%.

[Method of manufacturing fiber material]
Although not necessarily limited to the following, the above-mentioned fiber material 10A can be produced by performing a half-cut process on the above-mentioned needle-punched nonwoven fabric. The half-cut process may be performed according to a known method. That is, a blade or the like may be applied to the nonwoven fabric under conditions in which a cut of a predetermined thickness is made in the mat-like nonwoven fabric.

In the case where the fiber material 10A contains microballoons as described above, the microballoons can be encapsulated in the fiber material 10A at any stage during the manufacturing process of the fiber material 10A. For example, a material that serves as a precursor of the microballoons can be encapsulated in the fiber material 10A, and then the precursor can be expanded by heating to encapsulate the microballoons in the fiber material 10A.

The obtained fiber material 10A may be wound into a roll, and such rolled fiber material 10A may be the subject of commercial trade.

On the other hand, the fiber material 10A can be obtained by performing a needle punch process on a nonwoven fabric in which the notches 3 have been formed.

[Uses of fiber materials]
In addition, the fiber material 10A of this embodiment is used by impregnating it with a curable composition, as an example. That is, in this embodiment, it can be said that a curable material (mat-shaped curable material) obtained by impregnating the above-mentioned fiber material 10A with a curable composition can be provided. Here, since the fiber material 10A has needle punch marks 2, the curable composition is appropriately impregnated, which can contribute to improving the strength of the curable material after curing. Below, an example of a curable composition that can be used will be described.

[Curable composition]
The curable composition that can be impregnated into the fiber material 10A may be a known curable composition, typically including a resin material. The curable composition of the present embodiment may be a thermosetting composition or a photocurable composition, but is preferably a thermosetting composition because of its high ease of handling. The curable composition of the present embodiment is preferably a combination of a component that generates radicals and a component that is polymerized by the generated radicals. Below, the components that can be included in the curable composition that is preferably used will be described.

(Radically Polymerizable Compound (A))
The curable composition of the present embodiment may contain a radically polymerizable compound (A).
This radically polymerizable compound (A) is typically a compound that contains a radically polymerizable group (typically a carbon-carbon unsaturated bond) in its chemical structure, and may be appropriately selected from known materials.

More specifically, the radical polymerizable compound (A) may contain a resin component such as a vinyl ester resin, an unsaturated polyester resin, a urethane (meth)acrylate resin, a polyester (meth)acrylate resin, or a polyether (meth)acrylate resin. In addition, when the curable composition contains a resin component in this manner, the composition of the present embodiment can also be called a "(curable) resin composition."
The radically polymerizable compound (A) may contain a radically polymerizable monomer or a polymer of this radically polymerizable monomer.

Among these, the curable composition of the present embodiment preferably contains, as the radical polymerizable compound (A), one or more resins selected from the group consisting of vinyl ester resins, unsaturated polyester resins, and urethane (meth)acrylate resins.
In addition, the curable composition of the present embodiment preferably contains a radical polymerizable monomer as the radical polymerizable compound (A). In addition, it is also a preferred embodiment to configure the radical polymerizable compound (A) by combining the various resin components described above with the radical polymerizable monomer.
The component corresponding to this radically polymerizable compound (A) will be further explained below.

Vinyl ester resin The vinyl ester resin in this embodiment can be produced by a known method. For example, a desired resin can be obtained by reacting (condensing) an epoxy resin with (meth)acrylic acid in an inert gas stream or in an air atmosphere in the presence or absence of a known inhibitor or a known esterification catalyst. If necessary, other radical polymerizable monomers or organic solvents can be added to the reaction system in order to reduce the melt viscosity of the reaction system. Since this vinyl ester resin is obtained by the above-mentioned production method, it is also called an "epoxy (meth)acrylate resin".

The vinyl ester resin in the present embodiment can be, for example, a resin having an acrylate or methacrylate double bond at a molecular terminal obtained by addition reaction of acrylic acid or methacrylic acid with an epoxy resin having two or more glycidyl ether groups in one molecule.
The epoxy resin having two or more glycidyl ether groups in one molecule may be, for example, a bisphenol-type epoxy resin made from bisphenol A, bisphenol F, bisphenol S, etc., or a derivative thereof; a bixylenol-type epoxy resin made from bixylenol and its derivatives; a biphenol-type epoxy resin made from biphenol and its derivatives; a naphthalene-type epoxy resin made from naphthalene and its derivatives; or a novolac-type epoxy resin.
These can be used alone or in combination of two or more. The epoxy equivalent, which is a measure of the molecular weight of the epoxy resin, is preferably 174 to 2000 eq/g.

Unsaturated Polyester Resin In the present embodiment, the unsaturated polyester resin can be obtained, for example, by a known dehydration condensation reaction of an unsaturated polybasic acid, a saturated polybasic acid, and glycols, and can usually have an acid value of 2 to 40 mgKOH/g. In producing the unsaturated polyester resin, a desired unsaturated polyester resin can be obtained by appropriately selecting and combining the acid components of the unsaturated polybasic acid and the saturated polybasic acid, and selecting and combining the glycols, and by appropriately selecting the blending ratio thereof, etc.

Examples of unsaturated polybasic acids include maleic acid, maleic anhydride, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and glutaconic acid.

Saturated polybasic acids include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, HET acid, tetrabromophthalic anhydride, etc.

Glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, hydrogenated bisphenol A, bisphenol A propylene oxide compound, cyclohexanedimethanol, dibromo neopentyl glycol, etc.

In this embodiment, among the unsaturated polyester resins, unsaturated polybasic acids such as fumaric acid and maleic anhydride, saturated polybasic acids such as isophthalic acid, terephthalic acid, and adipic acid are used, and unsaturated polyester resins using ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, cyclohexanedimethanol, or neopentyl glycol as the main glycol component are preferred.

Urethane (meth)acrylate Resin The urethane (meth)acrylate resin in this embodiment is a resin that can be obtained, for example, by reacting a polyalcohol and/or a polyester polyol and/or a polyether polyol having two or more hydroxyl groups in one molecule with a diisocyanate to obtain an isocyanate at a molecular terminal, and/or one or more isocyanates in one molecule, with a compound having an alcoholic hydroxyl group and one or more acrylate groups or methacrylate groups.
Alternatively, the resin can be obtained by first reacting a compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups with a diisocyanate so that an isocyanate group remains, and then reacting the remaining isocyanate group with a polyalcohol and/or a polyester polyol and/or a polyether polyol having two or more hydroxyl groups in one molecule.
In producing a urethane (meth)acrylate resin, the physical properties of the resin can be adjusted by appropriately selecting a combination of an isocyanate with a polyalcohol and/or a polyester polyol and/or a polyether polyol, and a compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups.

　Examples of compounds having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups include hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, phenoxyhydroxypropyl (meth)acrylate, trimethylolpropane di(meth)acrylate, and dipropylene glycol mono(meth)acrylate.

Examples of the polyalcohol having two or more hydroxyl groups in one molecule include neopentyl glycol, ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct.
In addition, the polyester polyol having two or more hydroxyl groups in one molecule can be a saturated polyester polyol having a molecular weight of 1,000 to 2,000 obtained by a dehydration condensation reaction between a polyalcohol such as neopentyl glycol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, hydrogenated bisphenol A, an ethylene oxide adduct of bisphenol A, or a propylene oxide adduct of bisphenol A, and a polybasic acid such as adipic acid, phthalic acid (anhydride), isophthalic acid, terephthalic acid, or trimellitic acid.
In addition, the polyether polyol having two or more hydroxyl groups in one molecule can be, for example, polyethylene glycol or polypropylene glycol having a molecular weight of 300 to 2000 obtained by a ring-opening reaction of ethylene oxide or propylene oxide, or polycaprolactone obtained by a ring-opening reaction of caprolactone.
These may be used alone or in combination of two or more kinds.

As the compound having two or more isocyanate groups in one molecule, an aromatic and/or aliphatic polyisocyanate compound is used, and examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, trifunctional isocyanates having an isocyanurate ring obtained by trimerizing a bifunctional isocyanate compound, and commercially available isocyanate prepolymers modified with polyols.
These may be used alone or in combination of two or more.

Polyester (meth)acrylate Resin The polyester (meth)acrylate resin in this embodiment is, for example, a resin obtained by esterification of a polyester polyol with acrylic acid or methacrylic acid.
Alternatively, it may be a resin obtained by reacting an acid-terminated polyester with an acrylate or methacrylate having a glycidyl group.
In producing the polyester (meth)acrylate resin, the properties of the polyester (meth)acrylate resin can be adjusted by appropriately selecting the polyester polyol and acrylic acid or methacrylic acid, or the acid-terminated polyester and the acrylate or methacrylate having a glycidyl group.

Polyether (meth)acrylate Resin The polyether (meth)acrylate resin in this embodiment is a resin obtained by esterifying, for example, a polyether polyol with acrylic acid or methacrylic acid.
Alternatively, it may be a resin obtained by reacting an acid-terminated polyether with an acrylate or methacrylate having a glycidyl group.
In producing a polyether (meth)acrylate resin, the properties of the polyester (meth)acrylate resin can be adjusted by appropriately selecting a polyether polyol and an acrylic acid or methacrylic acid, or an acid-terminated polyester and an acrylate or methacrylate having a glycidyl group.

Radically Polymerizable Monomer, etc. Examples of the radically polymerizable monomer in this embodiment include styrene, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, norbornene dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, and propylene oxide-added bisphenol A di(meth)acrylate.
The radical polymerizable monomer may be either a monomer that is solid at room temperature (25° C.) or a monomer that is liquid at room temperature (25° C.).

The curable composition of this embodiment may also contain a polymer of the above-mentioned radically polymerizable monomer as the radically polymerizable compound (A). Examples of such a polymer include diallyl phthalate prepolymer, titanate prepolymer, epoxy prepolymer, urethane prepolymer, and acrylate prepolymer.

The content of the radically polymerizable compound (A) in the entire curable composition is, for example, 25.5 mass% or more and 38 mass% or less, preferably 25.8 mass% or more and 36 mass% or less, and more preferably 26 mass% or more and 34 mass% or less.
By setting the resin in such a range, it becomes easier to balance the handleability during the molding process and the mechanical properties after curing.

When the radical polymerizable compound (A) contains a resin component, the content thereof is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, based on 100 parts by mass of the entire radical polymerizable compound (A). By setting the content of the resin component within such a range, moldability in the molding process is improved.
The entire radical polymerizable compound (A) may be used as the resin component, but the content of the resin component may be 95 parts by mass or less or 90 parts by mass or less when the entire radical polymerizable compound (A) is taken as 100 parts by mass.

In addition, when the radical polymerizable compound (A) contains a radical polymerizable monomer, the content thereof is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, when the total amount of the radical polymerizable compound (A) is 100 parts by mass. Setting the content of the radical polymerizable monomer within such a range improves the workability of construction.
The entire radical polymerizable compound (A) may be a radical polymerizable monomer, but the content of the radical polymerizable monomer may be 95 parts by mass or less or 90 parts by mass or less when the entire radical polymerizable compound (A) is 100 parts by mass.

(Radical Generator (B))
The curable composition of the present embodiment may also contain a radical generator (B).
As described above, the curable composition of the present embodiment may contain the radical polymerizable compound (A). That is, by including the radical generator (B) in the composition in this manner, the polymerization reaction of the radical polymerizable compound (A) can be appropriately advanced, and the curability of the composition can be ensured.

Examples of the radical generator (B) include peroxides (organic peroxides) such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-n-propyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butyl peroxypivalate, and t-butylperoxy-2-ethylhexanate; hydrogen peroxide; and azo compounds such as 2,2'-azobis-isobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile.
In addition to these components, in the present embodiment, a sub-material for improving the radical generating ability may be present, and these may be combined and used in the radical generator (B). In this specification, these combinations may be collectively referred to as "radical generator (B)".

The radical generator (B) of the present embodiment is preferably a combination of a peroxide (B1) and an organic acid cobalt compound (B2), which is capable of easily generating radicals at low temperatures.
Specific examples include a combination of Permec N (trade name, methyl ethyl ketone peroxide, manufactured by NOF Corporation) and a cobalt compound such as cobalt naphthenate, cobalt octylate, or cobalt octenate; and a combination of Perbutyl Z (trade name, tertiary butyl perbenzoate, manufactured by NOF Corporation) and a cobalt compound such as cobalt naphthenate, cobalt octylate, or cobalt octenate.

The content of the radical generator (B) in the curable composition of the present embodiment is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 8 parts by mass, and even more preferably 0.3 to 5 parts by mass, relative to 100 parts by mass of the radical polymerizable compound (A).
By setting the content within such a range, it becomes easier to achieve a balance between the curability of the composition and the mechanical properties after curing.

(Other ingredients)
In addition, the curable composition of the present embodiment may contain additives other than the above components, such as resins other than the above, thixotropic agents, thixotropic assistants, fillers, silane coupling agents, polymerization accelerators such as dimethylaniline, polymerization inhibitors such as hydroquinone, viscosity reducing agents, anti-settling agents, colorants containing one or more selected from the group consisting of dyes such as green, red, blue, yellow, and black, pigments such as black pigments, and dyes, stress reducing agents, antifoaming agents, leveling agents, foaming agents, antioxidants, ion trapping agents, and rubber components, within the scope of the present invention. These may be used alone or in combination of two or more.

The above-mentioned thixotropic agents may be either organic or inorganic. Organic thixotropic agents may include fatty acid amides (amide wax type) synthesized from vegetable oil fatty acids and amines; hydrogenated castor oil type; oxidized polyethylene type; polymerized oil type; surfactant type; and urea modified compounds. Inorganic thixotropic agents may include clay minerals such as bentonites, talc, and mica. The amount of these thixotropic agents to be used may be appropriately determined according to the purpose.

The thixotropic auxiliary may be, for example, a polyhydroxycarboxylic acid ester derivative, a polycarboxylic acid amide derivative, or a polyether phosphate derivative.
As the polyhydroxycarboxylic acid ester derivative, for example, BYK-R 606 (manufactured by BYK Japan KK, product name) can be used. As the polycarboxylic acid amide derivative, for example, BYK-405 and BYK-R 605 (manufactured by BYK Japan KK, product names) can be used. As the polyether phosphate derivative, for example, Disparlon 3500 (manufactured by Kusumoto Chemicals Co., Ltd., product name) can be used.

Other specific examples of the thixotropic auxiliary include anionic surfactants, cationic surfactants, nonionic surfactants, betaine type surfactants, and polyethylene glycol.
As the anionic surfactant, higher fatty acid alkali salts, alkyl sulfates, alkyl sulfonates, alkylaryl sulfonates, sulfosuccinate salts, etc. can be used. As the cationic surfactant, higher amine halogen acid salts, alkyl pyridinium halides, quaternary ammonium salts, etc. can be used. As the nonionic surfactant, polyethylene glycol alkyl ethers, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, fatty acid monoglycerides, etc. can be used. As the betaine type surfactant, amino acids, etc. can be used.
When polyethylene glycol is used as a thixotropic agent, the average molecular weight is arbitrary, but can be set to 200 or more and 1,500 or less, for example, 250 or more and 1,000 or less.

Furthermore, the above-mentioned fillers may include silica, alumina, calcium carbonate, magnesium carbonate, barium carbonate, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, etc. These fillers may be used alone or in combination with multiple types, and their particle size and blending amount may be set as desired.

(Method for producing curable composition)
The curable composition of the present embodiment can be produced by mixing the above-mentioned materials.
For example, the materials are mixed using a mixer such as a homodisper, homomixer, universal mixer, planetary mixer, kneader, or three-roll mill to obtain a desired curable composition.
The temperature conditions and stirring conditions during mixing may be appropriately set depending on the materials used.

[Applications of curable materials (laminates)]
The above-mentioned curable material contains a curable composition, and therefore, a cured product can be obtained by subjecting it to a predetermined curing condition (that is, such a cured product can be said to be obtained by curing the curable material). Here, the curable material can be used, for example, for producing various laminates. This laminate typically comprises a cured product of the above-mentioned curable material and another material laminated on a first surface of the cured product and/or a surface opposite to the first surface.

A more specific example of such a laminate will be described with reference to the drawings. Figure 3 is a cross-sectional view showing a laminate 100 to which a fiber material 10A is applied.

The laminate 100 shown in FIG. 3 has fiber reinforced plastics 11, 12 laminated on the top and bottom surfaces (the first surface and the surface opposite the first surface) of the cured material 20A. Here, this cured material 20A is a cured curable material using the fiber material 10A. Here, the fiber reinforced plastics 11, 12 are a composite of a fiber base material and a curable composition. In other words, the fiber reinforced plastics 11, 12 shown in FIG. 3 may be a composite of a fiber base material and a cured product of a curable composition (which may be referred to as FRP).

The fiber base material that can be used to make up the fiber reinforced plastics 11 and 12 can be glass fiber, carbon fiber, aramid fiber, Zylon fiber, vinylon fiber, polyethylene fiber, boron fiber, basalt fiber, cellulose, etc. Among these fiber base materials, it is preferable that the fiber base material that can be used to make up the fiber reinforced plastics 11 and 12 is glass fiber. By adopting such an embodiment, the strength, specific gravity, etc. of the FRP after hardening can be made favorable.

On the other hand, the curable composition may be the same as the curable composition constituting the curable material described above, or may be a different composition.

The fiber base material content in the fiber reinforced plastics 11 and 12 can be, for example, 10% to 90% by mass, and from the standpoint of mechanical properties and moldability, can be preferably 20% to 80% by mass.

On the other hand, the content of the cured product of the curable composition in the fiber reinforced plastics 11 and 12 can be, for example, 10% by mass to 90% by mass, and from the standpoint of mechanical properties and moldability, can be preferably 20% by mass to 80% by mass.

Such a laminate 100 can be manufactured, for example, by combining the following steps (S1) and (S2).
(S1) A step of laminating fiber-reinforced plastics 11, 12 (other materials) and the above-mentioned hardenable material. (S2) A step of hardening at least the hardenable material.

Step (S1) may be performed by first obtaining a curable material and then laminating it on fiber-reinforced plastic 11 or the like (other material), or by laminating fiber material 10A on fiber-reinforced plastic 11 or the like, and then impregnating the fiber material 10A with a curable composition to convert the fiber material 10A into a curable material. Note that while FIG. 3 shows a laminate 100 using one layer of curable material, the curable material to be laminated may be a combination of multiple fiber materials 10A (for example, two or more curable materials may be interposed between fiber-reinforced plastics 11, 12).

In step (S2), the curable composition contained in the curable material is cured, and the curing conditions can be set appropriately depending on the contents of the curable composition. For example, when a combination of peroxide (B1) and organic acid cobalt compound (B2) is used as the radical generator (B), curing can be performed near room temperature (for example, a temperature range of -5°C to 50°C). On the other hand, when heating is required for the radical generator (B) to generate radicals, heating conditions can be adopted depending on the type of radical generator (B). As an example, the heating conditions may be above 50°C, above 70°C, or above 100°C. The upper limit of the heating conditions is not limited, but an example is 300°C or less. For heating, a known oven or the like can be used.

In addition, step (S2) may be performed by heating the laminate of fiber-reinforced plastics 11, 12 and the curable material using a press molding machine or the like.

Note that while FIG. 3 shows an example in which fiber-reinforced plastics 11, 12 are used as the material that constitutes the laminate 100, the materials that can be laminated to the cured product 20A are not limited to these. For example, various metal members or ceramic members may be laminated to the cured product 20A. Furthermore, the material on which the cured product 20A is laminated does not necessarily have to have a flat surface. In other words, even if the material to be laminated has a curved surface, the fiber material 10A that serves as the base material for the cured product 20A has a notch 3, and therefore can be said to be easily conformable to the curved surface.

Furthermore, the laminate 100 may form various components. In other words, the application of the laminate 100 can be set appropriately. Examples include, but are not limited to, parts for electrical and electronic equipment, office automation equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and miscellaneous goods, lighting equipment, etc.

[Modification]
In addition, the fiber material of this embodiment may be as follows. Fig. 4 is a plan view showing a modified example of the fiber material. Note that the following fiber materials 10B, 10C, etc. may have the various characteristics described for the fiber material 10A.

That is, as shown in FIG. 4, the fiber material (fiber materials 10B, 10C) may be provided such that the notches 3 define a closed region with the notches 3 as boundaries when the fiber material is observed from the normal direction of the first surface. Here, this closed region may be configured to have various shapes such as a circle, an ellipse, a polygon (triangle, square, pentagon, hexagon), etc., but preferably the closed region has a polygonal shape as shown in FIG. 4 (FIG. 4 shows fiber material 10B having lattice-shaped notches 3 and fiber material 10C having honeycomb-shaped notches 3). By adopting such an embodiment, the handleability of the fiber material is further improved.

Note that while FIG. 1 shows a fiber material 10A with a notch 3 on the first surface, the fiber material may also have a notch 3 on the surface opposite the first surface, in addition to the first surface.

Furthermore, it may be provided in the following forms:

(1) A mat-shaped fiber material including a nonwoven fabric, the first surface of the fiber material having a notch extending from the first surface to the inside of the fiber material, and the fiber material having needle punch marks penetrating the fiber material.

(2) The fiber material described in (1) above, wherein when the fiber material is observed from the normal direction of the first surface, the notch defines a closed region with the notch as a boundary.

(3) In the fiber material described in (2) above, the closed region has a polygonal shape.

(4) The fiber material according to any one of (1) to (3) above, wherein the average thickness _T0 of the fiber material is in the range of 0.5 to 10 mm.

(5) The fiber material according to any one of (1) to (4) above, wherein a ratio T ₁ /T ₀ of the average depth T ₁ of the notches to the average thickness T ₀ of the fiber material is in the range of 0.1 to 0.99.

(6) A fiber material according to any one of (1) to (5) above, which contains microballoons therein.

(7) A mat-shaped curable material, which is obtained by impregnating a fiber material described in any one of (1) to (6) above with a curable composition.

(8) A cured product obtained by curing the curable material described in (7) above.

(9) A laminate comprising a cured product of the curable material described in (7) above, and another material laminated on the first surface of the cured product and/or on a surface opposite to the first surface.
Of course, this is not the case.

The present invention will be explained in more detail using the following examples. Note that the present invention is not limited to the following examples.

[Example]
First, a nonwoven fabric (thickness 3 mm) of a polyester sheet (PET) with a porosity of 60% was prepared. One side of this nonwoven fabric was subjected to a honeycomb structure cutout (half cut) treatment, and needle punch marks were made at arbitrary intervals. In this example, the length of one side of the honeycomb structure was set to 5 mm, the depth of the cutout was set to an average of 2.9 mm, the diameter of the needle punch marks was set to 1.0 mm, and the number (density) of the needle punch marks was set to 200/100 ^cm2 . The nonwoven fabric subjected to such treatment is hereinafter referred to as "Example fiber material (Example)".

[Comparative Example]
A fiber material was obtained in the same manner as in the example, except that the nonwoven fabric was not subjected to the half-cutting treatment. The fiber material thus obtained is hereinafter referred to as the "comparative fiber material (comparative example)".

<Appearance comparison>
FIG. 5 is a photograph showing the fiber material of the embodiment. FIG. 6 is a photograph showing a comparison between the fiber materials of the embodiment and the comparative example. As supported by FIG. 5, the fiber material of the embodiment is easily deformed by the notch. From this, the fiber material of the embodiment is expected to improve the shapeability when obtaining a composite material. In addition, FIG. 6A shows the fiber material of the embodiment laminated on a substrate having a curved surface, and FIG. 6B shows the fiber material of the comparative example laminated on a similar substrate. From the comparison of these figures, it is supported that the half-cut processing improves the ability to follow the curved surface of the substrate.

<Comparison of mechanical strength>
The following test pieces were prepared using the fiber materials of the examples and the comparative examples. First, two sheets of glass mat #450 were prepared, and the fiber materials of the examples and the comparative examples were placed between the glass mats to obtain a laminated structure. The laminated structure was impregnated with a curable composition by the VaRTM molding method, and cured to obtain a composite material. The curable composition used here was a mixture of unsaturated polyester resin "4072PT" manufactured by Nippon U-Pica Co., Ltd. and a curing agent (Permec N) manufactured by NOF Corporation. The blending amount of the curing agent was set to 1% by weight relative to the weight of the unsaturated polyester resin. The curing conditions were curing at room temperature for 24 hours, followed by post-curing at 80°C for 3 hours. The composite material thus obtained was cut into a predetermined shape to obtain a test piece. The thickness of the test piece here was 2.97 mm.

The bending strength and bending modulus of both test pieces obtained were measured in accordance with JIS K 7017. The results are shown in Table 1 below. In this test, a test speed of 1 mm/min was used, and for the test pieces using the fiber material of the example, the half-cut surface was placed downwards, and a load was applied from the surface opposite the half-cut surface to perform the measurements.

From the comparison in Table 1, when the fiber material of the embodiment is used, the mechanical strength of the resulting composite material is improved. Although not necessarily limited to the mechanism below, this improvement in mechanical strength is thought to be due to the curable composition (cured resin) flowing appropriately into the notches in the fiber material.

The above describes the embodiments of the present invention, but these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included.

1: nonwoven fabric, 2: needle punch mark, 3: notch, 10A, 10B, 10C: fiber material, 11, 12: fiber reinforced plastic, 20A: cured product, 100: laminate, T ₀ : average thickness, T ₁ : average depth

Claims (9)

A mat-like fiber material including a nonwoven fabric,
a first surface of the fibrous material has a notch extending from the first surface to an interior of the fibrous material;
The textile material has needle punch marks penetrating the textile material. The fiber material according to claim 1,
A fiber material, wherein when the fiber material is observed from the normal direction of the first surface, the notch defines a closed area with the notch as a boundary. The fiber material according to claim 2,
The closed region has a polygonal shape. The fiber material according to any one of claims 1 to 3,
The average thickness _T0 of the fiber material is in the range of 0.5 to 10 mm. The fiber material according to any one of claims 1 to 4,
A fiber material, wherein a ratio T ₁ /T ₀ of an average depth T ₁ of the notches to an average thickness T ₀ of the fiber material is in the range of 0.1 to 0.99. The fiber material according to any one of claims 1 to 5,
A textile material having microballoons therein. A mat-like curable material,
A curable material obtained by impregnating the fiber material according to any one of claims 1 to 6 with a curable composition. A cured product,
A cured product obtained by curing the curable material according to claim 7. A laminate comprising:
A cured product of the curable material according to claim 7;
Another material is laminated on the first surface of the cured product and/or on a surface opposite to the first surface;
A laminate comprising:

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