JP7560574B2 - Laminate, fiber-reinforced resin composite made of same, and method for producing fiber-reinforced resin composite - Google Patents

Description

The present invention relates to a laminate, a fiber-reinforced resin composite made of the laminate, and a method for producing the fiber-reinforced resin composite. More specifically, the present invention relates to a laminate that is excellent in rigidity, strength, low specific gravity, and appearance and is suitable for electric and electronic parts, household appliances, automobile-related parts, infrastructure-related parts, housing-related parts, etc., a fiber-reinforced resin composite made of the laminate, and a method for producing the fiber-reinforced resin composite.

Fiber-reinforced resin composites are used in a wide range of fields, including automobile and aircraft components, general industrial materials, and more, due to their light weight and high physical properties. These composites require not only mechanical properties but also surface appearance quality, so it is necessary to thoroughly impregnate the reinforcing fibers with resin and reduce voids.

To fully impregnate the reinforcing fibers with resin, thermosetting resins have been used as matrix resins. On the other hand, thermoplastic resins are inexpensive and have better impact resistance, heat resistance, and recyclability than thermosetting resins, but they have problems such as the difficulty of impregnating reinforcing fibers and the need for high-temperature, high-pressure molding compared to thermosetting resins, so they are not yet widely used.

Polypropylene resin is widely used industrially for electrical and electronic parts, home appliances, housings, packaging materials, and automobile parts, etc., because of its excellent moldability, chemical resistance, and low specific gravity. Furthermore, in recent years, due to the demand for lightweight automobiles, it has also been widely used in automobile applications such as bumpers and interior and exterior parts. For this reason, fiber-reinforced resin composites using polypropylene resin as the matrix resin have been studied in various ways as a material that combines light weight, rigidity, and strength. However, polypropylene resin does not have good adhesion to carbon fiber, so sufficient mechanical properties cannot be obtained by simply laminating the two. A composition has been proposed that contains carbon fiber chopped strands with a fiber length of about 0.1 to 6 mm and modified polypropylene grafted with acid anhydrides such as maleic anhydride in order to improve the adhesion of polypropylene resin. (Patent Documents 1 and 2). A sizing agent for carbon fiber bundles, mainly composed of urethane-modified epoxy resin and epoxy resin, has also been proposed (Patent Document 3). In addition, in order to improve the adhesion between carbon fibers having a fiber length of about 1 to 6 mm and polypropylene resin, it has been proposed to use a polypropylene resin containing a carboxylate bonded to the polymer chain (Patent Document 4).

It is known that these modified polyolefins react with functional groups such as carboxylic acids present on the surface of chopped-strand carbon fibers during melt-blending, chemically bonding the polyolefin to the surface of the carbon fibers, thereby improving adhesion to chopped-strand carbon fibers. However, when forming a composite with sheet-like carbon fibers that does not go through melt-blending, there is a problem that adhesion to the sheet-like carbon fibers is insufficient, resulting in insufficient mechanical properties.

On the other hand, in order to impart dimensional stability to polypropylene resin, which does not have sufficient dimensional stability, it has been proposed to blend and melt-knead polycarbonate resin, which has excellent dimensional stability. In this case, it has been proposed to include carbon milled fiber with a specific surface property in order to improve the compatibility between polypropylene resin and polycarbonate resin (Patent Document 5). According to this proposal, the adhesion between the carbon milled fiber and the resin component is improved. However, in the formation of a composite with sheet-shaped carbon fiber that does not go through melt-kneading, there is a problem that the adhesion with the sheet-shaped carbon fiber is insufficient, resulting in insufficient mechanical properties. It is also known that the adhesion is improved by adding polycarbonate resin to polypropylene resin (Patent Document 6). However, in order to replace products that use metal and thermosetting CFRP and to expand applications, further strength, rigidity, and high appearance are required.

Japanese Unexamined Patent Publication No. 55-50041 Japanese Unexamined Patent Publication No. 58-113239 Japanese Unexamined Patent Publication No. 61-252371 JP 2010-150359 A JP 2016-222774 A Patent No. 6744414

The object of the present invention is to solve the above problems and obtain a laminate having excellent adhesion between the thermoplastic resin and the reinforcing fibers and excellent rigidity, strength and appearance, and a fiber-reinforced resin composite comprising the same.

As a result of extensive research to solve these problems, the inventors discovered that a thermoplastic resin sheet made of a polypropylene resin composition consisting of polypropylene resin, polycarbonate resin and modified polyolefin resin can be laminated with a reinforcing fiber sheet to obtain a fiber-reinforced resin composite having excellent rigidity, strength and appearance without causing delamination or significant deterioration in physical properties due to incompatibility, thereby arriving at the present invention.

That is, according to the present invention, there is provided (1) a laminate of a reinforcing fiber sheet and a thermoplastic resin sheet, wherein the thermoplastic resin sheet is a resin composition containing 0.1 to 900 parts by weight of (C) modified polyolefin resin (component C) per 100 parts by weight of a resin component consisting of (A) 1 to 99 parts by weight of polypropylene resin (component A) and (B) 99 to 1 part by weight of polycarbonate resin (component B), and the content of the reinforcing fibers constituting the reinforcing fiber sheet is 151 to 900 parts by weight per 100 parts by weight of the resin components consisting of components A and B.
One of the more preferred embodiments of the present invention is (2) a laminate according to the above configuration (1), in which the component B is a polycarbonate resin containing 1 to 100 mol % of a carbonate structural unit represented by the following formula [1] in all carbonate structural units:

[In the above general formula [1], R ¹ and R ² each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group, and when there are a plurality of each, they may be the same or different, a and b each represent an integer of 1 to 4, and W represents a single bond or at least one group selected from the group consisting of groups represented by the following general formula [2].

(In the above general formula [2], R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ²⁰ each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group and a carboxyl group; R ^{R 21} , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and when there are a plurality of them, they may be the same or different, c is an integer of 1 to 10, d is an integer of 4 to 7, e is a natural number, f is 0 or a natural number, e+f is a natural number of 150 or less, and X is a divalent aliphatic group having 2 to 8 carbon atoms.
One of the more preferred embodiments of the present invention is the laminate according to the above constitution (1) or (2), characterized in that (3) component C is maleic anhydride-modified polypropylene.

One of the more preferred aspects of the present invention is a laminate according to any one of the above structures (1) to (3), characterized in that (4) the resin composition constituting the thermoplastic resin sheet further contains (D) 1 to 20 parts by weight of a styrene-based thermoplastic elastomer (component D) per 100 parts by weight of the resin component consisting of components A and B.

One of the more preferred aspects of the present invention is a laminate described in any one of the above configurations (1) to (4), in which (5) the reinforcing fiber sheet is a woven or knitted fabric, a nonwoven fabric, or a unidirectional sheet.

One of the more preferred aspects of the present invention is a laminate according to any one of the above configurations (1) to (5), in which the fiber constituting the reinforcing fiber sheet is at least one type of fiber selected from the group consisting of carbon fiber and glass fiber.

One of the more preferred aspects of the present invention is (7) a laminate described in the above configuration (6), in which the fibers constituting the reinforcing fiber sheet are carbon fibers having a surface oxygen concentration (O/C), which is the ratio of the number of oxygen (O) and carbon (C) atoms on the fiber surface as measured by X-ray photoelectron spectroscopy, of 0.15 or more.

One of the more preferred aspects of the present invention is a laminate described in any one of the above configurations (1) to (7), in which (8) the thermoplastic resin sheet is made of mesh-like hollow fibers.

One of the more preferred aspects of the present invention is (9) a fiber-reinforced resin composite comprising a laminate described in any one of the above configurations (1) to (8).

One of the more preferred aspects of the present invention is (10) a method for producing a fiber-reinforced resin composite, characterized in that a laminate described in any one of the above configurations (1) to (8) is pressure-treated at a temperature equal to or higher than the melting temperature of the thermoplastic resin constituting the thermoplastic resin sheet and lower than the heat resistance temperature of the reinforcing fiber constituting the reinforcing fiber sheet.

The laminate of the present invention is a material that is highly flexible and has excellent conformability to molds, etc. Furthermore, a fiber-reinforced resin composite obtained by heating and pressurizing this laminate has excellent strength, rigidity, and appearance, and is useful for electrical and electronic parts, home appliances, automobile-related parts, infrastructure-related parts, housing-related parts, etc., and the industrial effects it provides are exceptional.

FIG. 2 is a schematic diagram of a cross section of a hollow fiber used in the present invention. 1 is a cross-sectional view of a hollow fiber used in the present invention, taken by an electron microscope. FIG. 2 is a schematic diagram showing a method for measuring the degree of irregularity of a hollow fiber used in the present invention. FIG. 2 is a schematic cross-sectional view of a laminate of the present invention. FIG. 1 is a schematic diagram of a cross-sectional view of a fiber-reinforced resin composite of the present invention.

The present invention will be specifically described below.
<Laminate>
(Component A: Polypropylene resin)
The polypropylene resin used as component A of the polypropylene resin composition constituting the thermoplastic resin sheet in the present invention is a polymer of propylene, but in the present invention, it also includes copolymers with other monomers. An example of the polypropylene resin in the present invention is a homopolypropylene resin. In addition, it includes a block copolymer of propylene and ethylene, a block copolymer of propylene and an α-olefin having 4 to 10 carbon atoms (also called "block polypropylene"), a random copolymer of propylene and ethylene, and a random copolymer of propylene and an α-olefin having 4 to 10 carbon atoms (also called "random polypropylene"). In addition, "block polypropylene" and "random polypropylene" are collectively called "polypropylene copolymer".

In the present invention, one or more of the above-mentioned homopolypropylene resin, block polypropylene, and random polypropylene may be used as the polypropylene resin, and among these, homopolypropylene and block polypropylene are preferred. Note that the polypropylene resin does not include modified polypropylene resin, which is component C.

Examples of α-olefins having 4 to 10 carbon atoms used in polypropylene copolymers include 1-butene, 1-pentene, isobutylene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, and 3-methyl-1-hexene.

The content of ethylene in the polypropylene copolymer is preferably 5% by weight or less of the total monomers. The content of α-olefins having 4 to 10 carbon atoms in the polypropylene copolymer is preferably 20% by weight or less of the total monomers.

The polypropylene copolymer is preferably a copolymer of propylene and ethylene or a copolymer of propylene and 1-butene, and particularly preferably a copolymer of propylene and ethylene.

The melt flow rate (230°C, 2.16 kg) of the polypropylene resin in the present invention is preferably 0.1 to 5 g/10 min, more preferably 0.2 to 4 g/10 min, and particularly preferably 0.3 to 3 g/10 min. If the melt flow rate of the polypropylene resin is less than 0.1 g/10 min, the moldability is poor due to high viscosity, and if it exceeds 5 g/10 min, sufficient toughness may not be exhibited. The melt flow rate is also called "MFR". The MFR was measured in accordance with ISO1133.
(Component B: polycarbonate resin)
The polycarbonate resin used as component B of the resin composition constituting the thermoplastic resin sheet is usually one obtained by reacting a dihydroxy compound with a carbonate precursor by an interfacial polycondensation method or a melt transesterification method. Other examples include one obtained by polymerizing a carbonate prepolymer by a solid-phase transesterification method or one obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method.

The dihydroxy component used here may be any dihydroxy component that is normally used in aromatic polycarbonates, and may be a bisphenol or an aliphatic diol. As the bisphenol, a bisphenol represented by the following formula [3] is preferably used.

[In the above general formula [3], R ¹ and R ² each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group, and when there are a plurality of each, they may be the same or different, a and b each represent an integer of 1 to 4, and W represents a single bond or at least one group selected from the group consisting of groups represented by the following general formula [2].

(In the above general formula [2], R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ^{R 21} , R 22 , R 23 , R 24 , R 25 and R 26 each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a ^nitro group, an ^{aldehyde group} , a ^cyano group and a ^carboxyl group; Each of ²⁶ is independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and when there are a plurality of them, they may be the same or different, c is an integer of 1 to 10, d is an integer of 4 to 7, e is a natural number, f is 0 or a natural number, e+f is a natural number of 150 or less, and X is a divalent aliphatic group having 2 to 8 carbon atoms.
Specific examples of bisphenols include 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)propane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxanthane), and the like. 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)diphenylmethane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)diphenylmethane, 4,4'-Dihydroxydiphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-dihydr Examples of such hydroxy-3,3'-diphenyldiphenyl sulfoxide include 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis(4-hydroxyphenyl)cyclohexane, 1,3-bis(4-hydroxyphenyl)cyclohexane, 4,8-bis(4-hydroxyphenyl)tricyclo[5.2.1.02,6]decane, 4,4'-(1,3-adamantanediyl)diphenol, and 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane.

Examples of aliphatic diols include 2,2-bis-(4-hydroxycyclohexyl)-propane, 1,14-tetradecanediol, octaethylene glycol, 1,16-hexadecanediol, 4,4'-bis(2-hydroxyethoxy)biphenyl, bis{(2-hydroxyethoxy)phenyl}methane, 1,1-bis{(2-hydroxyethoxy)phenyl}ethane, 1,1-bis{(2-hydroxyethoxy)phenyl}-1-phenylethane, 2,2-bis{(2-hydroxyethoxy)phenyl}propane, 2,2-bis{(2-hydroxyethoxy)-3-methylphenyl}propane, 1,1-bis{(2-hydroxyethoxy)phenyl}-3,3,5-trimethylcyclohexane, 2,2-bis{4-(2-hydroxyethoxy)phenyl}methane, 1,1-bis{(2-hydroxyethoxy)phenyl}ethane, 1,1-bis{(2-hydroxyethoxy)phenyl}-1-phenylethane, 2,2-bis{(2-hydroxyethoxy)phenyl}propane, 2,2-bis{(2-hydroxyethoxy)-3-methylphenyl}propane, 1,1-bis{(2-hydroxyethoxy)phenyl}-3,3,5-trimethylcyclohexane, 1,1-bis{(2-hydroxyethoxy)phenyl}decane, 2,2-bis{3-bromo-4-(2-hydroxyethoxy)phenyl}propane, 2,2-bis{3,5-dimethyl-4-(2-hydroxyethoxy)phenyl}propane, 2,2-bis{3-cyclohexyl-4-(2-hydroxyethoxy)phenyl}propane, 2,2-bis{3-t-butyl-4-(2-hydroxyethoxy)phenyl}butane, 2,2-bis{(2-hydroxyethoxy)phenyl}-4-methylpentane, 2,2-bis{(2-hydroxyethoxy)phenyl}octane, 1,1-bis{(2-hydroxyethoxy)phenyl}decane, 2,2-bis{3-bromo-4-(2-hydroxyethoxy)phenyl}propane, 2,2-bis{3,5-dimethyl-4-(2-hydroxyethoxy)phenyl}propane, 2,2-bis{3-cyclohexyl-4-(2-hydroxyethoxy)phenyl} Propane, 1,1-bis{3-cyclohexyl-4-(2-hydroxyethoxy)phenyl}cyclohexane, bis{(2-hydroxyethoxy)phenyl}diphenylmethane, 9,9-bis{(2-hydroxyethoxy)phenyl}fluorene, 9,9-bis{4-(2-hydroxyethoxy)-3-methylphenyl}fluorene, 1,1-bis{(2-hydroxyethoxy)phenyl}cyclohexane, 1,1-bis{(2-hydroxyethoxy)phenyl}cyclopentane, 4,4'-bis(2-hydroxyethoxy)diphenyl ether, 4,4'-bis(2-hydroxyethoxy)-3,3'-dimethyldiphenyl ether, 1,3-bis[2-{(2-hydroxyethoxy)phenyl}propyl]benzene, 1,4-bis[2-{(2-hydroxyethoxy)phenyl}propyl]benzene, 1,4-bis{(2-hydroxyethoxy)phenyl}propyl]benzene, 1,4-bis{(2-hydroxyethoxy)phenyl}cyclohexane, 1,3-bis{(2-hydroxyethoxy)phenyl}cyclohexane, 4,8-bis{(2-hydroxyethoxy)phenyl}tricyclo[5.2.1.02,6]decane, 1,3-bis{(2-hydroxyethoxy)phenyl}-5,7-dimethyladamantane, 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 1,4:3,6-dianhydro-D-sorbitol (isosorbide), 1,4:3,6-dianhydro-D-mannitol (isomannide), 1,4:3,6-dianhydro-L-iditol (isoidide), and the like.

Among these, aromatic bisphenols are preferred, and in particular 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene. In particular, 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are preferred. Among these, 2,2-bis(4-hydroxyphenyl)propane is the most suitable because of its excellent strength and good durability. These may be used alone or in combination of two or more kinds.

The polycarbonate resin used as component B of the present invention may be made into a branched polycarbonate resin by using a branching agent in combination with the above-mentioned dihydroxy compound.

Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate resins include trisphenols such as phloroglucine, phloroglucide, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2, 2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, and 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol. Other examples include tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, etc. Other examples include trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof, etc. Among these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.

These polycarbonate resins are produced by known reaction methods for producing ordinary aromatic polycarbonate resins, for example, by reacting an aromatic dihydroxy component with a carbonate precursor such as phosgene or a carbonic acid diester. The basic steps for the production method are briefly described below.

In a reaction using, for example, phosgene as a carbonate precursor, the reaction is usually carried out in the presence of an acid binder and a solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used. In addition, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used to promote the reaction. In this case, the reaction temperature is usually 0 to 40°C, and the reaction time is several minutes to 5 hours. In an ester exchange reaction using a carbonic acid diester as a carbonate precursor, a predetermined ratio of aromatic dihydroxy components is stirred with the carbonic acid diester while heating in an inert gas atmosphere, and the resulting alcohol or phenol is distilled off. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is usually in the range of 120 to 300°C. The reaction is completed by reducing the pressure from the beginning and distilling off the resulting alcohol or phenol. In addition, a catalyst usually used in an ester exchange reaction can be used to promote the reaction. Examples of the carbonic acid diester used in the transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, etc. Among these, diphenyl carbonate is particularly preferred.

In polymerization reactions, end terminators may be used. End terminators are used to adjust the molecular weight, and the resulting polycarbonate resin has superior thermal stability compared to unblocked polycarbonate resins, since the ends are blocked. Examples of such end terminators include monofunctional phenols represented by the following general formulas [4] to [6].

[In the formula, A is a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an alkylphenyl group (the alkyl portion has 1 to 9 carbon atoms), a phenyl group, or a phenylalkyl group (the alkyl portion has 1 to 9 carbon atoms), and r is an integer of 1 to 5, preferably 1 to 3.]

[In the formula, Y is -R-O-, -R-CO-O-, or -R-O-CO-, where R represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and n represents an integer of 10 to 50.]
Specific examples of the monofunctional phenols represented by the above general formula [4] include phenol, isopropylphenol, p-tert-butylphenol, p-cresol, p-cumylphenol, 2-phenylphenol, 4-phenylphenol, and isooctylphenol.

In addition, the monofunctional phenols represented by the above general formulas [5] to [6] are phenols having a long-chain alkyl group or an aliphatic ester group as a substituent. When these are used to block the ends of polycarbonate resin, they not only function as end terminators or molecular weight regulators, but also improve the melt fluidity of the resin, facilitating molding and processing, and have the effect of lowering the water absorption rate of the resin, and are therefore preferably used.

As the substituted phenols of the above general formula [5], those in which n is 10 to 30, particularly 10 to 26, are preferred. Specific examples include decylphenol, dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, eicosylphenol, docosylphenol, and triacontylphenol.

As the substituted phenol of the above general formula [6], a compound in which Y is -R-CO-O- and R is a single bond is preferred, and n is preferably 10 to 30, particularly 10 to 26. Specific examples include decyl hydroxybenzoate, dodecyl hydroxybenzoate, tetradecyl hydroxybenzoate, hexadecyl hydroxybenzoate, eicosyl hydroxybenzoate, docosyl hydroxybenzoate, and tricontyl hydroxybenzoate.

Among these monofunctional phenols, the monofunctional phenols represented by the above general formula [4] are preferred, more preferably alkyl- or phenylalkyl-substituted phenols, and particularly preferably p-tert-butylphenol, p-cumylphenol, or 2-phenylphenol. It is desirable that the terminal terminator of these monofunctional phenols is introduced into at least 5 mol %, preferably at least 10 mol %, of the total terminals of the obtained polycarbonate resin, and the terminal terminator may be used alone or in combination of two or more kinds.

The polycarbonate resin used as component B of the present invention may be a polyester carbonate copolymerized with an aromatic dicarboxylic acid, such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid or a derivative thereof, within the scope of the present invention.

The viscosity average molecular weight of the polycarbonate resin used as component B of the present invention is preferably in the range of 13,000 to 25,000, more preferably 13,000 to 21,000, even more preferably 16,000 to 21,000, and most preferably 16,000 to 20,000. If the molecular weight exceeds 25,000, the melt viscosity may become too high and moldability may be poor, and if the molecular weight is less than 13,000, problems may occur in mechanical strength. The viscosity average molecular weight referred to in the present invention is first calculated by using an Ostwald viscometer to determine the specific viscosity calculated by the following formula from a solution in which 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride at 20°C, and the calculated specific viscosity is inserted into the following formula to determine the viscosity average molecular weight M.

Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds that methylene chloride falls, and t is the number of seconds that the sample solution falls]
η _SP /c = [η] + 0.45 × [η] ² c (where [η] is the intrinsic viscosity)
[η]=1.23× ^10-4 M ^0.83
c=0.7
The polycarbonate resin used as component B of the present invention has a total Cl (chlorine) content in the resin of preferably 0 to 200 ppm, more preferably 0 to 150 ppm. If the total Cl content in the polycarbonate resin exceeds 200 ppm, This is not preferred since it may result in poor color and thermal stability.

The content of component B is 99 to 1 part by weight, preferably 50 to 5 parts by weight, more preferably 25 to 5 parts by weight, and most preferably 15 to 5 parts by weight, per 100 parts by weight of the total of components A and B. If the content of component B is more than 99 parts by weight, the improvement in appearance when the fiber-reinforced resin composite is formed is insufficient. If the content of component B is less than 1 part by weight, the adhesion between the resin and the reinforcing fiber is reduced, and the strength when the fiber-reinforced composite is formed is not sufficiently exhibited, and the improvement in appearance is also insufficient.
(Component C: Modified polyolefin resin)
The resin composition constituting the thermoplastic resin sheet contains a modified polyolefin resin as a compatibilizer. The modified polyolefin resin improves the interfacial adhesion between the polypropylene resin and the reinforcing fibers, thereby improving the strength of the fiber-reinforced resin composite.

The modified polyolefin resin is preferably an acid-modified polyolefin resin modified with an unsaturated carboxylic acid or its derivative. Examples of modified polyolefin resins include polyethylene resins and polypropylene resins, with polypropylene resins being preferred. Modified polypropylene resins include propylene homopolymers, propylene random copolymers, propylene block copolymers, and the like. Methods such as graft modification and copolymerization can be used to modify polyolefin resins.

Examples of unsaturated carboxylic acids used to modify polyolefin resins include acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, and angelic acid. Derivatives of the unsaturated carboxylic acids include acid anhydrides, esters, amides, imides, and metal salts. Examples include maleic anhydride, itaconic anhydride, citraconic anhydride, nadic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, maleic acid monoamide, maleimide, N-butylmaleimide, sodium acrylate, and sodium methacrylate. Among these, unsaturated dicarboxylic acids and their derivatives are preferred, and maleic anhydride or phthalic anhydride is particularly preferred.

The crystallization temperature (Tc) of the modified polypropylene resin is preferably 90 to 125°C, more preferably 110 to 120°C. The intrinsic viscosity is preferably 0.1 to 2.4 dl/g, more preferably 0.2 to 1.6 dl/g. The crystallization temperature (Tc) of the modified polyolefin resin can be measured by a differential scanning calorimeter (DSC). The intrinsic viscosity of the modified polyolefin resin can be measured in tetralin at 135°C. The amount of carboxylic acid added to the modified polyolefin resin is preferably in the range of 0.1 to 14% by weight, more preferably in the range of 0.8 to 8% by weight. The amount of acid added can be determined by measuring the IR spectrum of the acid-modified polyolefin resin and determining the area of the peak at 1670 cm ^-1 to 1810 cm ^-1 .

The content of the modified polyolefin resin is 0.1 to 900 parts by weight, preferably 1 to 500 parts by weight, more preferably 5 to 300 parts by weight, and even more preferably 50 to 150 parts by weight, relative to 100 parts by weight of the total of components A and B. If the content of the modified polyolefin resin is less than 0.1 part by weight, the strength of the fiber-reinforced resin composite is not improved, and if it exceeds 900 parts by weight, the sheet processability is deteriorated, so that the strength of the fiber-reinforced composite is not fully expressed and the improvement in appearance is also insufficient.
(Component D: styrene-based thermoplastic elastomer)
The resin composition constituting the thermoplastic resin sheet may further contain a styrene-based thermoplastic elastomer, which improves the compatibility between the polypropylene resin and the polycarbonate resin and improves the strength (flexural modulus and flexural strength) of the fiber-reinforced resin composite.

Examples of styrene-based thermoplastic elastomers include styrene-ethylene/butylene-styrene block copolymers, styrene-hydrogenated butadiene-styrene triblock copolymers, styrene-isoprene-styrene triblock copolymers, styrene-hydrogenated isoprene-styrene triblock copolymers, styrene-hydrogenated butadiene diblock copolymers, styrene-hydrogenated isoprene diblock copolymers, and styrene-isoprene diblock copolymers, of which styrene-ethylene/butylene-styrene block copolymers are the most suitable.

Also preferably used are block copolymers represented by the following formula (I) or (II):
X-(Y-X) _n ...(I)
(X-Y) _n ...(II)
In general formulas (I) and (II), X is a styrene polymer block, and in formula (I), the degrees of polymerization at both ends of the molecular chain may be the same or different. Y is at least one selected from an isoprene polymer block, a hydrogenated butadiene polymer block, and a hydrogenated isoprene polymer block. Also, n is an integer of 1 or more.

The content of the X component in the block copolymer is preferably in the range of 20 to 80% by weight, more preferably 25 to 70% by weight. If this amount is less than 20% by weight, the rigidity of the resin composition tends to decrease. If it exceeds 80% by weight, the moldability and impact strength tend to decrease. Specific examples of such block copolymers include styrene-hydrogenated butadiene-styrene triblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-hydrogenated isoprene-styrene triblock copolymer, styrene-hydrogenated butadiene diblock copolymer, styrene-hydrogenated isoprene diblock copolymer, and styrene-isoprene diblock copolymer.

The weight average molecular weight of the styrene-based thermoplastic elastomer is preferably 250,000 or less, more preferably 220,000 or less, and even more preferably 200,000 or less. If the weight average molecular weight exceeds 250,000, the moldability may decrease and the dispersibility in polypropylene resin may also deteriorate. In addition, the lower limit of the weight average molecular weight is not particularly limited, but 40,000 or more is preferable, and 50,000 or more is more preferable. The weight average molecular weight was measured by the following method. That is, the molecular weight is measured in polystyrene equivalent by gel permeation chromatography, and the weight average molecular weight is calculated.

The content of the styrene-based thermoplastic elastomer is preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, further preferably 5 to 13 parts by weight, and most preferably 5 to 10 parts by weight, relative to 100 parts by weight of the resin component. If the content of the styrene-based thermoplastic elastomer is less than 1 part by weight, the strength of the fiber-reinforced resin composite is not improved, whereas if the content exceeds 20 parts by weight, gas is generated during molding of the fiber-reinforced resin composite, which may result in reduced moldability.
(Other ingredients)
Various additives can be blended into the resin composition constituting the thermoplastic resin sheet within the range that does not impair the effects of the present invention. Examples of such additives include phosphorus-based heat stabilizers, phenol-based heat stabilizers, sulfur-containing antioxidants, release agents, ultraviolet absorbers, hindered amine-based light stabilizers, compatibilizers, flame retardants, dyes and pigments, etc. These additives will be specifically described below.
(Phosphorus-based heat stabilizer)
As the phosphorus-based heat stabilizer, any of a phosphite compound, a phosphonite compound, and a phosphate compound can be used.

Various phosphite compounds can be used. Specific examples include the phosphite compounds represented by the following general formula [7], the phosphite compounds represented by the following general formula [8], and the phosphite compounds represented by the following general formula [9].

[In the formula, R ³¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkaryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, or a halo, alkylthio (alkyl group has 1 to 30 carbon atoms) or hydroxyl substituent thereof, and the three R ³¹ may be selected to be the same or different from one another, and a cyclic structure may also be selected by being derived from a dihydric phenol.]

[In the formula, R ³² and R ³³ each represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms, or a 2-(4-oxyphenyl)propyl-substituted aryl group having 15 to 25 carbon atoms. The cycloalkyl group and aryl group may be either unsubstituted or substituted with an alkyl group.]

[In the formula, R ³⁴ and R ³⁵ are alkyl groups having 12 to 15 carbon atoms. R ³⁴ and R ³⁵ may be the same or different.]
Examples of the phosphonite compound include a phosphonite compound represented by the following general formula [10] and a phosphonite compound represented by the following general formula [11].

[In the formula, Ar ¹ and Ar ² represent an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 6 to 20 carbon atoms, or a 2-(4-oxyphenyl)propyl-substituted aryl group having 15 to 25 carbon atoms, and the four Ar ^1s may be selected to be the same or different from one another. Or, the two Ar ^2s may be selected to be the same or different from one another.]
Preferable specific examples of the phosphite compound represented by the above general formula [7] include diphenyl isooctyl phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, diphenyl mono(tridecyl) phosphite, phenyl diisodecyl phosphite, and phenyl di(tridecyl) phosphite.

Specific examples of preferred phosphite compounds represented by the above general formula [8] include distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, dicyclohexyl pentaerythritol diphosphite, etc. Preferred examples include distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite. Such phosphite compounds can be used alone or in combination of two or more.

A preferred example of the phosphite compound represented by the above general formula [9] is 4,4'-isopropylidenediphenol tetratridecyl phosphite.

Specific preferred examples of the phosphonite compound represented by the above general formula [10] include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3' -biphenylene diphosphonite, tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite, etc. Among these, tetrakis(di-tert-butylphenyl)-biphenylene diphosphonite is preferred, and tetrakis(2,4-di-tert-butylphenyl)-biphenylene diphosphonite is more preferred. The tetrakis(2,4-di-tert-butylphenyl)-biphenylene diphosphonite is preferably a mixture of two or more kinds. Specifically, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite can be used alone or in combination of two or more thereof, and a mixture of these three types is preferred.

Specific preferred examples of the phosphonite compound represented by the above general formula [11] include bis(2,4-di-iso-propylphenyl)-4-phenyl-phenyl phosphonite, bis(2,4-di-n-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenyl phosphonite, bis(2,4-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-iso-propylphenyl)-4-phenyl-phenyl phosphonite, bis(2,6-di-n-butylphenyl)-3-phenyl-phenyl phosphonite, bis(2,6-di-tert-butylphenyl)-4-phenyl-phenyl phosphonite, bis(2,6-di-tert-butylphenyl)-3-phenyl-phenyl phosphonite, and the like. Bis(di-tert-butylphenyl)-phenyl-phenyl phosphonite is preferred, and bis(2,4-di-tert-butylphenyl)-phenyl-phenyl phosphonite is more preferred.

This bis(2,4-di-tert-butylphenyl)-phenyl-phenylphosphonite is preferably a mixture of two or more kinds. Specifically, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonite and bis(2,4-di-tert-butylphenyl)-3-phenyl-phenylphosphonite can be used in combination, either alone or in combination. A mixture of these two kinds is preferred. In the case of a mixture of two kinds, the mixing ratio by weight is preferably in the range of 5:1-4, and more preferably in the range of 5:2-3.

On the other hand, examples of phosphate compounds include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, and diisopropyl phosphate. Trimethyl phosphate is preferred.

Among the above phosphorus-based heat stabilizers, more preferred compounds include those represented by the following general formulas [12] and [13].

[In formula [12], R ³⁶ and R ³⁷ each independently represent an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group having 1 to 12 carbon atoms.]

[In formula [13], R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁷ , R ⁴⁸ and R ⁴⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, R ⁴⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴⁶ represents a hydrogen atom or a methyl group.]
In formula [12], R ³⁶ and R ³⁷ are preferably alkyl groups having 1 to 12 carbon atoms, and more preferably alkyl groups having 1 to 8 carbon atoms.

Specific examples of the compound represented by formula [12] include tris(dimethylphenyl)phosphite, tris(diethylphenyl)phosphite, tris(di-iso-propylphenyl)phosphite, tris(di-n-butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,6-di-tert-butylphenyl)phosphite, and tris(2,6-di-tert-butylphenyl)phosphite. Tris(2,6-di-tert-butylphenyl)phosphite is particularly preferred.

Specific examples of the compound represented by formula [13] include a phosphite derived from 2,2'-methylenebis(4,6-di-tert-butylphenol) and 2,6-di-tert-butylphenol, and a phosphite derived from 2,2'-methylenebis(4,6-di-tert-butylphenol) and phenol. In particular, a phosphite derived from 2,2'-methylenebis(4,6-di-tert-butylphenol) and phenol is preferred.

The content of the phosphorus-based heat stabilizer is preferably 0.001 to 3.0 parts by weight, more preferably 0.01 to 2.0 parts by weight, and even more preferably 0.05 to 1.0 parts by weight, relative to 100 parts by weight of the total of components A and B. If the content of the phosphorus-based heat stabilizer is less than 0.001 part by weight, the mechanical properties may not be fully exhibited, and even if it exceeds 3.0 parts by weight, the mechanical properties may not be fully exhibited.
(Phenol-based heat stabilizer)
The phenol-based heat stabilizer used in the present invention generally includes hindered phenol, semi-hindered phenol, and less hindered phenol compounds. In view of providing a heat stabilizing formulation to polypropylene-based resins, the hindered phenol compounds are particularly preferably used.

Specific examples of such hindered phenol compounds include vitamin E, n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenylacrylate, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-dimethyl ethylene-bis(6-α-methyl-benzyl-p-cresol), 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-butylidene-bis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate pionate, 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, bis[2-tert-butyl-4-methyl 6-(3-tert-butyl-5-methyl-2-hydroxybenzyl)phenyl]terephthalate, 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1,-dimethylethyl 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, 4,4'-di-thiobis(2,6-di-tert-butyl) butylphenol), 4,4'-trithiobis(2,6-di-tert-butylphenol), 2,4-bis(n-octylthio)-6-(4-hydroxy-3',5'-di-tert-butylanilino)-1,3,5-triazine, N,N'-hexamethylenebis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxy 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, socyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 1,3,5-tris-2[3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl isocyanurate, tetrakis[methylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate]methane, etc. These can be preferably used.

More preferred are n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1,-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, and tetrakis[methylene-3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate]methane. Furthermore, n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate is preferred.
(Sulfur-containing antioxidants)
The resin composition constituting the thermoplastic resin sheet may contain a sulfur-containing antioxidant as an antioxidant, which is particularly suitable when the resin composition is used for rotational molding or compression molding.

Specific examples of such sulfur-containing antioxidants include dilauryl-3,3'-thiodipropionic acid ester, ditridecyl-3,3'-thiodipropionic acid ester, dimyristyl-3,3'-thiodipropionic acid ester, distearyl-3,3'-thiodipropionic acid ester, laurylstearyl-3,3'-thiodipropionic acid ester, pentaerythritol tetra(β-laurylthiopropionate) ester, bis[2-methyl-4-(3-laurylthiopropionyloxy)-5-tert-butylphenyl]sulfide, octadecyl disulfide, mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, 1,1'-thiobis(2-naphthol), etc. More preferably, pentaerythritol tetra(β-laurylthiopropionate) ester can be mentioned.

The phosphorus-based heat stabilizer, phenol-based heat stabilizer, and sulfur-containing antioxidant listed above can be used alone or in combination of two or more kinds. The content of the phenol-based heat stabilizer and the sulfur-containing antioxidant is preferably 0.0001 to 1 part by weight per 100 parts by weight of the total of the A component and the B component. It is more preferably 0.0005 to 0.5 parts by weight, and even more preferably 0.001 to 0.2 parts by weight.
(Release Agent)
The resin composition constituting the thermoplastic resin sheet may further contain a release agent for the purpose of improving the productivity during molding and reducing distortion of the molded product. As such a release agent, a known one may be used.

Examples include saturated fatty acid esters, unsaturated fatty acid esters, polyolefin waxes (polyethylene wax, 1-alkene polymers, etc. Those modified with functional group-containing compounds such as acid-modified waxes can also be used), silicone compounds, fluorine compounds (fluorine oils such as polyfluoroalkyl ethers), paraffin wax, beeswax, etc.

Among these, fatty acid esters are preferred as release agents. Such fatty acid esters are esters of aliphatic alcohols and aliphatic carboxylic acids. Such aliphatic alcohols may be monohydric alcohols or polyhydric alcohols having dihydric or higher valences. The number of carbon atoms in the alcohol is preferably in the range of 3 to 32, and more preferably in the range of 5 to 30.

Examples of such monohydric alcohols include dodecanol, tetradecanol, hexadecanol, octadecanol, eicosanol, tetracosanol, ceryl alcohol, and triacontanol.

Such polyhydric alcohols include pentaerythritol, dipentaerythritol, tripentaerythritol, polyglycerol (triglycerol to hexaglycerol), ditrimethylolpropane, xylitol, sorbitol, and mannitol. Polyhydric alcohols are more preferred in the fatty acid esters of the present invention.

On the other hand, it is preferable that the aliphatic carboxylic acid has 3 to 32 carbon atoms, and particularly preferable that the aliphatic carboxylic acid has 10 to 22 carbon atoms.

Examples of the aliphatic carboxylic acid include saturated aliphatic carboxylic acids such as decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, behenic acid, icosanoic acid, and docosanoic acid, as well as unsaturated aliphatic carboxylic acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, eicosapentaenoic acid, and cetoleic acid. Of the above, the aliphatic carboxylic acid is preferably one having 14 to 20 carbon atoms. Among them, saturated aliphatic carboxylic acids are preferred. Stearic acid and palmitic acid are particularly preferred.

The above-mentioned aliphatic carboxylic acids such as stearic acid and palmitic acid are usually produced from natural fats and oils such as animal fats and oils such as beef tallow and lard, and vegetable fats and oils such as palm oil and sunflower oil, and therefore these aliphatic carboxylic acids are usually mixtures containing other carboxylic acid components with different numbers of carbon atoms. Therefore, in the production of the fatty acid ester of the present invention, aliphatic carboxylic acids produced from such natural fats and oils and in the form of a mixture containing other carboxylic acid components, particularly stearic acid and palmitic acid, are preferably used.

The fatty acid ester used in the present invention may be either a partial ester or a full ester (full ester). However, partial esters usually have a high hydroxyl value and are prone to inducing decomposition of the resin at high temperatures, so full esters are more preferable. The acid value of the fatty acid ester of the present invention is preferably 20 or less, more preferably in the range of 4 to 20, and even more preferably in the range of 4 to 12, from the viewpoint of thermal stability. The acid value can be substantially 0. The hydroxyl value of the fatty acid ester is more preferably in the range of 0.1 to 30. The iodine value is preferably 10 or less. The iodine value can be substantially 0. These properties can be determined by the method specified in JIS K 0070.

The content of the release agent is preferably 0.005 to 2 parts by weight, more preferably 0.01 to 1 part by weight, and even more preferably 0.05 to 0.5 part by weight, based on 100 parts by weight of the total of the A component and the B component.
(Ultraviolet absorber)
The resin composition constituting the thermoplastic resin sheet of the present invention may contain an ultraviolet absorbing agent.

Examples of benzophenones include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxytrihydridolate benzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sodium sulfoxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.

In the benzotriazole series, for example, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylf phenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), 2,2'-p-phenylenebis(1,3-benzoxazin-4-one), and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole. Other examples include polymers having a 2-hydroxyphenyl-2H-benzotriazole skeleton, such as copolymers of 2-(2'-hydroxy-5-methacryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with said monomer, and copolymers of 2-(2'-hydroxy-5-acryloxyethylphenyl)-2H-benzotriazole and vinyl monomers copolymerizable with said monomer.

Examples of hydroxyphenyltriazines include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-methyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-ethyloxyphenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-propyloxyphenol, and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-butyloxyphenol. Further examples include compounds in which the phenyl group of the above-mentioned compounds is a 2,4-dimethylphenyl group, such as 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hexyloxyphenol.

Examples of cyclic imino esters include 2,2'-p-phenylenebis(3,1-benzoxazine-4-one), 2,2'-(4,4'-diphenylene)bis(3,1-benzoxazine-4-one), and 2,2'-(2,6-naphthalene)bis(3,1-benzoxazine-4-one).

Examples of cyanoacrylates include 1,3-bis-[(2'-cyano-3',3'-diphenylacryloyl)oxy]-2,2-bis[(2-cyano-3,3-diphenylacryloyl)oxy]methyl)propane and 1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene.

Furthermore, the ultraviolet absorber may be a polymer type ultraviolet absorber obtained by copolymerizing such an ultraviolet absorbing monomer and/or a light stable monomer having a hindered amine structure with a monomer such as an alkyl (meth)acrylate by adopting a structure of a monomer compound capable of radical polymerization. Suitable examples of the ultraviolet absorbing monomer include compounds containing a benzotriazole skeleton, a benzophenone skeleton, a triazine skeleton, a cyclic imino ester skeleton, and a cyanoacrylate skeleton in the ester substituent of the (meth)acrylic acid ester.

Among the above, benzotriazole and hydroxyphenyltriazine are preferred in terms of UV absorption, and cyclic iminoester and cyanoacrylate are preferred in terms of heat resistance and hue (transparency). The above UV absorbents may be used alone or in a mixture of two or more.

The content of the ultraviolet absorber is preferably 0.01 to 2 parts by weight, more preferably 0.02 to 2 parts by weight, even more preferably 0.03 to 1 part by weight, and still more preferably 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the total of the A component and the B component.
(Hindered amine light stabilizer)
The resin composition constituting the thermoplastic resin sheet may contain a hindered amine light stabilizer. The hindered amine light stabilizer is generally called HALS (hindered amine light stabilizer), and is a compound having a 2,2,6,6-tetramethylpiperidine skeleton in its structure.

For example, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, Siloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl) Carbonate, bis(2,2,6,6-tetramethyl-4-piperidyl)oxalate, bis(2,2,6,6-tetramethyl-4-piperidyl)malonate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)adipate, bis(2,2,6,6-tetramethyl-4-piperidyl)terephthalate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)carbonate, bis(1,2,2,6,6-pentamethyl-4 -piperidyl) oxalate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) malonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) adipate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) terephthalate, N,N'-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3-benzenedicarboxamide, 1,2-bis(2,2,6,6-tetramethyl-4-piperidyl) N,N',N'',N'''-tetrakis-(4,6-bis-(butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazin-2-yl)-4,7-diazadecane-1,10-diamine, polycondensate of dibutylamine/1,3,5-triazine/N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{ (2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,4-tricarboxylate, 1- [2-{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, and a condensation product of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethanol.

Hindered amine light stabilizers are broadly divided into three types according to the bond partner of the nitrogen atom in the piperidine skeleton: N-H type (hydrogen bonded to the nitrogen atom), N-R type (an alkyl group (R) bonded to the nitrogen atom), and N-OR type (an alkoxy group (OR) bonded to the nitrogen atom). When applied to polycarbonate resins, it is more preferable to use the N-R type or N-OR type, which have low basicity, from the viewpoint of the basicity of the hindered amine light stabilizer. The above hindered amine light stabilizers can be used alone or in combination of two or more types.

The content of the hindered amine light stabilizer is preferably 0 to 1 part by weight, more preferably 0.05 to 1 part by weight, even more preferably 0.08 to 0.7 parts by weight, and particularly preferably 0.1 to 0.5 parts by weight, relative to 100 parts by weight of the total of the A component and the B component. If the content of the hindered amine light stabilizer is more than 1 part by weight, this is not preferred because it may cause poor appearance due to gas generation or a decrease in physical properties due to decomposition of the polycarbonate resin. If the content is less than 0.05 parts by weight, sufficient light resistance may not be achieved.
(Flame retardant)
A flame retardant can be blended into the resin composition constituting the thermoplastic resin sheet to impart flame retardancy. As such a flame retardant, various compounds known as flame retardants for thermoplastic resins can be used, but more preferably, (i) halogen-based flame retardants (e.g., brominated polycarbonate compounds, etc.), (ii) phosphorus-based flame retardants (e.g., monophosphate compounds, phosphate oligomer compounds, phosphonate oligomer compounds, phosphonitrile oligomer compounds, phosphonic acid amide compounds, and phosphazene compounds, etc.), (iii) metal salt-based flame retardants (e.g., organic sulfonic acid alkali (earth) metal salts, boric acid metal salt-based flame retardants, and stannic acid metal salt-based flame retardants, etc.), and (iv) silicone-based flame retardants made of silicone compounds. The blending of compounds used as flame retardants not only improves flame retardancy, but also improves, for example, antistatic properties, fluidity, rigidity, and thermal stability based on the properties of each compound.

The content of the flame retardant is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 28 parts by weight, and even more preferably 0.08 to 25 parts by weight, relative to 100 parts by weight of the total of Components A and B. If the content of the flame retardant is less than 0.01 part by weight, sufficient flame retardancy may not be obtained, whereas if it exceeds 30 parts by weight, there may be a large decrease in impact strength and chemical resistance.
(dyes and pigments)
The resin composition constituting the thermoplastic resin sheet can further contain various dyes and pigments to provide molded products with a variety of designs. By blending fluorescent whitening agents or other fluorescent dyes that emit light, it is possible to provide even better design effects that make use of the emitted color. It is also possible to provide fiber-reinforced resin compositions that are colored with extremely small amounts of dyes and pigments and have vivid color development.

Examples of fluorescent dyes (including fluorescent whitening agents) include coumarin-based fluorescent dyes, benzopyran-based fluorescent dyes, perylene-based fluorescent dyes, anthraquinone-based fluorescent dyes, thioindigo-based fluorescent dyes, xanthene-based fluorescent dyes, xanthone-based fluorescent dyes, thioxanthene-based fluorescent dyes, thioxanthone-based fluorescent dyes, thiazine-based fluorescent dyes, and diaminostilbene-based fluorescent dyes. Among these, coumarin-based fluorescent dyes, benzopyran-based fluorescent dyes, and perylene-based fluorescent dyes are preferred because they have good heat resistance and are less susceptible to deterioration during molding of polycarbonate resin.

Dyes other than the above bluing agents and fluorescent dyes include perylene dyes, coumarin dyes, thioindigo dyes, anthraquinone dyes, thioxanthone dyes, ferrocyanides such as Prussian blue, perinone dyes, quinoline dyes, quinacridone dyes, dioxazine dyes, isoindolinone dyes, and phthalocyanine dyes. Furthermore, the resin composition of the present invention can be blended with a metallic pigment to obtain better metallic colors. As metallic pigments, those having a metal coating or a metal oxide coating on various plate-like fillers are suitable.

The content of the dye or pigment is preferably 0.00001 to 1 part by weight, and more preferably 0.00005 to 0.5 parts by weight, per 100 parts by weight of the total of the components A and B.
(Other resins)
The polypropylene resin composition constituting the thermoplastic resin sheet may contain other resins in small proportions within the range in which the effects of the present invention are exhibited.

Examples of such other resins include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, silicone resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyolefin resins other than polypropylene resins, polymethacrylate resins, phenolic resins, and epoxy resins.
(Other fillers)
The resin composition constituting the thermoplastic resin sheet may contain other fillers in small proportions within the range in which the effects of the present invention are exhibited.

Examples of such other fillers include fibrous fillers such as potassium titanate whiskers, zinc oxide whiskers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers, and silicates such as wollastonite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicate, as well as swellable layered silicates such as montmorillonite and synthetic mica, metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide, calcium phosphate, and silica, and non-fibrous fillers.
(Other additives)
The resin composition constituting the thermoplastic resin sheet of the present invention may contain small amounts of additives known per se in order to impart various functions to the molded product or improve its characteristics. These additives may be added in normal amounts as long as they do not impair the object of the present invention. Examples of such additives include sliding agents (e.g., PTFE particles), fluorescent dyes, inorganic phosphors (e.g., phosphors with aluminate as the host crystal), antistatic agents, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents (e.g., fine titanium oxide particles, fine zinc oxide particles), radical generators, infrared absorbing agents (heat ray absorbing agents), and photochromic agents.
(Method for producing resin composition)
There is no particular limitation on the method for producing the resin composition constituting the thermoplastic resin sheet, and a well-known method can be used. For example, the components are mixed in a solution state, and the solvent is evaporated or precipitated in the solvent. From an industrial point of view, a method of kneading the components in a molten state is preferable. For melt kneading, a kneading device such as a single-screw or twin-screw extruder or various kneaders that are commonly used can be used. In particular, a twin-screw high-speed kneader is preferable. In melt kneading, the cylinder setting temperature of the kneading device is preferably in the range of 200 to 360°C, more preferably in the range of 200°C to 300°C, and even more preferably in the range of 230 to 280°C. In kneading, each component may be uniformly mixed in advance in a device such as a tumbler or a Henschel mixer, or if necessary, a method of omitting mixing and separately supplying each component to the kneading device in a fixed amount can be used.
(Thermoplastic resin sheet)
The thermoplastic resin sheet used in the present invention is prepared by overlapping a reinforcing fiber sheet and applying pressure treatment at a temperature equal to or higher than the melting temperature of the thermoplastic resin constituting the thermoplastic resin sheet and lower than the heat resistance temperature of the reinforcing fibers constituting the reinforcing fiber sheet, so that the thermoplastic resin sheet melts and is arranged around the reinforcing fibers without any gaps, forming a fiber-reinforced resin composite.

The form of the thermoplastic resin sheet used in the present invention is not particularly limited, but in order to achieve the above object, at least one dimension of the three dimensions of length, width, and thickness is preferably in the range of 1 to 300 μm, more preferably 1 to 100 μm, even more preferably 1 to 50 μm, and most preferably 1 to 30 μm. Examples of the thermoplastic resin sheet that can have such a form include a film, a nonwoven fabric, and a mesh-like fiber sheet as described below, and among them, a mesh-like fiber sheet is preferred from the viewpoint of impregnation of the periphery of the reinforcing fiber of the thermoplastic resin sheet.
(Mesh fiber sheet)
In the present invention, by forming the thermoplastic resin sheet into a mesh-like fiber sheet, it is possible to obtain higher adhesion to the reinforcing fiber compared to a normal nonwoven fabric made of fibers without a mesh structure. Furthermore, in order to obtain high adhesion to the reinforcing fiber, it is preferable that the cross-sectional shape of the hollow fiber is an irregular noncircular cross-section. Here, "hollow" does not necessarily mean that there are obvious voids like known hollow fibers, but may also mean that there are air bubbles inside the fiber.

The hollow fibers described in this invention have air bubbles inside the fibers, but it is preferable that they have discontinuous air bubbles inside and are fibrous objects with irregular, non-circular cross sections, as shown diagrammatically in Figure 1, for example.

More specifically, as shown in the electron microscope photograph in Figure 2, it is preferable that the material be a flat fibrous material having multiple bubbles of different shapes inside.

Here, the bubbles inside the irregular fiber refer to closed spaces (voids) present inside the fiber. Usually, the voids inside synthetic fibers are voids that are continuous in the fiber axis direction and have the same cross-sectional shape, as seen in hollow fibers. In contrast, the preferred voids of the present invention are in the form of discontinuous bubbles. In the present invention, it is preferable to have such discontinuous bubbles with different cross-sectional shapes in the length direction of the fiber inside the hollow fiber. When discontinuous voids in the form of bubbles, which are the preferred shape of the present invention, exist, it is possible to uniformly improve the fluidity of the thermoplastic resin, unlike in the case of normal continuous voids. As a result, it is possible to exhibit particularly excellent impregnation properties in the composite with reinforcing fibers, compared to continuous voids.

The thermoplastic resin fiber used in the present invention has air bubbles inside the fiber as described above, and the hollow ratio in the cross section of a single fiber is preferably in the range of 0.5 to 40%. Here, the hollow ratio refers to the ratio of the total area of the air bubbles in the cross section of the fiber when multiple air bubbles are contained in the cross section of the fiber. Furthermore, the hollow ratio of the fiber is preferably in the range of 1 to 30%, particularly 5 to 20%. If the hollow ratio of the fiber is less than 0.5%, the impregnation when compounded with the reinforcing fiber may be insufficient, and if it exceeds 40%, not only will the strength of the nonwoven fabric structure decrease, but in the fiber manufacturing process such as spinning, especially in the case of irregular fibers, there will be a tendency for fiber breakage to occur frequently, resulting in a decrease in manufacturing efficiency.

This hollow ratio was determined by calculating the area of the hollow portion relative to the total cross-sectional area including the hollow portion of the fiber from a cross-sectional photograph of the fiber taken at 100x magnification using a scanning electron microscope (SEM). In the present invention, the presence of such hollow portions makes the walls of the fiber cross-section thinner and easier to melt, improving moldability, especially for fine portions. However, if the hollow ratio of the fiber is too high, the thermal conductivity of the entire hollow fiber decreases, and molding efficiency tends to decrease.

The size of each individual bubble is preferably in the range of 0.1 to 100 μm. In particular, it is preferably in the range of 0.5 to 50 μm. If the bubble size is smaller than 0.1 μm, impregnation may be insufficient when compounding with reinforcing fibers, and if it is larger than 100 μm, not only will compounding with reinforcing fibers not occur uniformly, but defects (bubbles) may remain inside the fiber-reinforced plastic.

In the present invention, irregular fibers are preferably used, and the irregular non-circular cross section of the peripheral cross section of the irregular fiber is preferably a shape with a disordered cross section rather than a regular cross section such as an ellipse or a regular polygon. In ordinary synthetic fibers, the cross section depends on the shape of the spinneret, so it is generally a regular cross section. This is because an irregular spinneret shape increases the occurrence rate of thread breakage during melt spinning. However, if the irregular cross section is regular, when forming a nonwoven fabric, other fibers may fit into the irregular part of the fiber and be closely packed, which may actually reduce the voids. The mesh-like fiber of the present invention is preferably a fiber with a cross section that is different from the above and does not depend on the spinneret shape. The fiber that constitutes the thermoplastic resin sheet of the present invention is preferably a irregular fiber obtained by slit spinning using a foaming agent, for example, as described later.

And because it has such an irregular outer cross section and mesh-like shape, not only will gaps inevitably occur where each irregularly shaped fiber overlaps, but the gaps between the fibers will also take on a variety of shapes. The gaps between the fibers will not be uniform, and there will be less overlap between the fibers. In addition, the irregular shape will result in random bending stiffness and material density. And because of this randomness, when combined with reinforcing fibers, it will ultimately be possible to have uniform mechanical properties.

The end face angle of the hollow fiber used in the present invention is preferably less than 60 degrees, more preferably 1 to 55 degrees, and even more preferably 3 to 45 degrees. This end face angle is determined from a fiber cross-section photograph taken at 100 times magnification using a scanning electron microscope (SEM), as in the measurement of the hollow ratio described above. A straight line (short axis) is defined at the thickest part in a direction perpendicular to a straight line (long axis) connecting both ends of the fiber cross section, and the angle of the long axis end of the triangle connecting both ends of the short axis and the three points of the long axis end closer to the short axis is determined, and this is the end face angle. When this end face angle is less than 60 degrees, the hollow fiber made of thermoplastic resin can easily penetrate between the reinforcing fibers, and higher impregnation can be ensured.

The irregular fiber preferably used in the present invention has a degree of irregularity in the cross section of the single fiber that is greater than 1 and not greater than 20. Furthermore, the degree of irregularity is preferably 2 to 10. Here, the degree of irregularity of the cross section of the fiber is a value defined by the ratio D1/D2 of the circumscribing circle diameter D1 and the inscribing circle diameter D2 of the single fiber cross section shown in FIG. 3. When this degree of irregularity is within the above-mentioned preferred range, excellent impregnation can be achieved when composited with reinforcing fibers. More specifically, this degree of irregularity is determined from a fiber cross section photograph obtained at a magnification of 100 times using a scanning electron microscope (SEM), as in the measurement of the hollow ratio, etc., and the diameter D1 of the circumscribing circle in the fiber cross section and the diameter D2 of the inscribing circle are measured, and the ratio (D1/D2) is calculated as the degree of irregularity. Contrary to the end face angle, a large value of this degree of irregularity makes it easier for hollow fibers made of thermoplastic resin to penetrate between the reinforcing fibers, making it possible to ensure higher impregnation.

In the method for producing a mesh-like fiber sheet of the present invention, first, in order to obtain irregular fibers, a thermoplastic resin to which a foaming agent has been added is extruded through a slit die and molded. At this time, the thermoplastic resin extruded from the slit die becomes a thin sheet, but since the thermoplastic resin used in the present invention contains a foaming agent, it foams in the resin when extruded from the slit die, and air bubbles pass through the outside of the thin sheet to form a mesh-like sheet. At the same time, each fiber constituting the mesh-like sheet becomes an irregular fiber. Conversely, air bubbles that do not escape to the outside but remain inside the resin form voids inside the irregular fiber. Figure 1 is a schematic diagram of this. The electron microscope photograph in Figure 2 is a cross-sectional photograph of an assembly of irregular fibers produced by such a process of the present invention. Thus, in the present invention, the thermoplastic resin contains a foaming agent, but the foaming agent is a foamable substance that can become a gas when the molten resin is extruded from the slit die. This foaming agent is not necessarily a substance that foams itself, and the resin itself may also serve as a foaming agent that has the property of generating such a gas, or it may be a substance that helps generate gas. Specific methods for obtaining a mesh fiber sheet include, for example, a method of kneading a substance such as an inert gas that is a gas at room temperature, such as nitrogen gas or carbon dioxide gas, into a molten thermoplastic resin; a method of kneading a substance that is liquid at room temperature but becomes a gas at the melting temperature of the thermoplastic resin, such as water, with a molten thermoplastic resin; a method of kneading a substance that generates a gas upon decomposition, such as a diazo compound or sodium carbonate, with a molten thermoplastic resin; and a method of kneading a polymer that generates a gas upon reaction with a part of a molten thermoplastic resin such as polycarbonate (e.g., polyester, polyamide) with such a molten thermoplastic resin.

In either method, it is sufficient that when the thermoplastic resin is extruded in a molten state through the slit die, gas is generated from the die along with the resin, and it is preferable that the various foaming substances and the thermoplastic resin are thoroughly mixed before being extruded through the slit die. If the mixing is not sufficient, it may be difficult to obtain a mesh-like fiber sheet or irregularly shaped fibers that are uniform and have the desired physical properties.

At the same time, in the manufacturing method of the present invention, it is preferable to generate bubbles inside the fiber. An inert gas is particularly suitable as a foaming agent for this purpose. When an inert gas is used, a small amount of the inert gas dissolves in the thermoplastic resin under the high temperature and pressure conditions during melt spinning. Then, when extruded from the slit die, particularly when an inert gas is used, a large number of tiny bubbles are generated. In the present invention, the generation of bubbles during the spinning process, and further the elution of the dissolved inert gas, allow discontinuous bubbles to be stably generated inside the irregular fiber.

It is preferable to quickly cool the resin extruded from the die. This cooling is a factor that determines the size of the mesh at the mesh fiber sheet stage, and the fiber diameter and shape of the final irregularly shaped fibers, so it is desirable to control it carefully. For example, if you want to produce a mesh fiber sheet with a large fiber diameter and large mesh, you can reduce the cooling. The opposite is true if you want a small fiber diameter and finer mesh. Air cooling is generally the preferred method for this cooling, and the mesh and fiber diameter can be adjusted by changing the air volume, but it is also possible to use a liquid such as water or to bring it into contact with a cooled solid.

In addition, in the method of manufacturing this mesh fiber sheet, it is preferable to extrude the thermoplastic resin together with the foaming agent in a molten state from a slit die, and then withdraw the discharged resin at a sufficient speed. If the withdrawal speed is insufficient, the strength of the resulting mesh fiber sheet or irregular fiber may be weakened, and in extreme cases, the sheet may have large holes, and uniform irregular fibers may not be obtained. The guideline for this withdrawal speed is expressed as a draft ratio, which is usually 10 times or more, and preferably 20 to 400 times. It is further preferable to withdraw at a draft ratio of 300 times or less, and particularly 20 to 200 times. If the draft ratio is too low here, the fibers tend to become too thick. Conversely, if it is too high, thread breakage tends to occur, making it difficult to manufacture a stable mesh fiber sheet. Here, draft means stretching the fibers to orient the resin molecules and improve strength. The draft ratio used here is expressed as the ratio of the withdrawal speed to the linear speed of the resin passing through the die. If extension, as described below, is performed during collection, the draft rate is calculated by converting it to the speed when extension is not performed.

Furthermore, one method for adjusting the mesh size of the mesh-like fiber sheet used in the present invention and the fiber diameter of the irregular fibers is to change the melt viscosity of the resin. Methods for changing this melt viscosity include, for example, changing the temperature conditions, changing the degree of polymerization of the resin, using a plasticizer, or a combination of these, but changing the temperature conditions is the simplest and most preferable. In addition, the degree of irregularity, hollowness, and shape of the hollow voids of the aforementioned irregular fibers can be adjusted by the amount of foaming substance added during spinning, the temperature conditions, the draft rate, etc.

It is preferable that the irregular fiber of the present invention passes through the state of a mesh fiber sheet as described above during the manufacturing process. By passing through the form of a mesh fiber sheet, it becomes possible to easily draft and extend at a large magnification, and stable productivity can be ensured. As a result, irregular fibers with sufficient strength can be easily obtained. In the present invention, it is preferable that the irregular fiber in the nonwoven fabric structure contains air bubbles inside and has an irregular noncircular cross-sectional shape. However, such irregular fibers usually have low strength and are very difficult to produce industrially in a stable manner. However, by passing through the form of a mesh fiber sheet as described above, it is possible to stably produce high-strength irregular fibers with little thread breakage.

In addition, such a mesh fiber sheet can be made into a more uniform and high-strength mesh fiber sheet by the spreading process described below, and since it has excellent impregnation into the reinforcing fiber sheet, the composite after molding can have high physical properties. Here, the spreading process refers to a process of spreading the mesh by stretching the mesh fiber sheet in the horizontal direction. Specific methods include, for example, a method of spreading the mesh fiber sheet in the horizontal direction while holding both ends, and a method of spreading the mesh fiber sheet extruded from a circular slit in the diameter direction of the slit. In particular, a method of stacking a large number of sheets and spreading them in the horizontal direction while holding both ends is preferable. Not only is the industrial productivity higher than other methods, but the stacking improves the uniformity in the thickness direction and width direction. The method of spreading in the horizontal direction may be any method, such as a method of spreading by holding only both ends, a method of dividing the sheet into several zones in the width direction and spreading each zone, or other methods, as described above. When the above spreading is performed, it may be performed on one mesh fiber sheet as it is, or two or more sheets may be stacked. When two or more sheets are laminated, the number of sheets is preferably in the range of 2 to 2000, and more preferably 10 to 1000. The mesh fiber sheets to be laminated may be of the same type, or multiple mesh fiber sheets made of different polymers may be laminated together. Furthermore, it is also possible to combine a nonwoven fabric web made of short fibers and a long fiber nonwoven fabric such as a spunbond nonwoven fabric.
(Reinforcing fiber sheet)
The reinforcing fibers constituting the reinforcing fiber sheet used in the laminate of the present invention are preferably reinforcing fibers having a heat resistance of 350° C. or higher.

Specifically, inorganic fibers such as high-strength carbon fibers, glass fibers, and metal fibers, and organic synthetic fibers such as aromatic polyamide fibers can be used. Furthermore, these may be used alone or in combination of two or more. As metal fibers, for example, stainless steel fibers can be mentioned, which are preferable in terms of electrical conductivity and mechanical properties. In addition, the surface of the reinforcement fiber may be coated or vapor-deposited with a metal. For example, nickel-coated carbon fibers are preferable in terms of electrical conductivity. In particular, carbon fibers and glass fibers with high strength and high elasticity are preferable, and further, in order to obtain a laminate with high rigidity, carbon fibers, more specifically, polyacrylonitrile (PAN)-based, petroleum/coal pitch-based, rayon-based, lignin-based, and other carbon fibers can be mentioned. In particular, PAN-based carbon fibers made from PAN are preferable because of their excellent productivity and mechanical properties on an industrial scale.

The reinforcing fibers used in the present invention may be any fiber shape that is long in one direction, and the concept includes not only general fibers and filaments, but also so-called whiskers, etc.

More specifically, examples of reinforcing fibers suitable for use in the present invention include glass fibers, flat cross-section glass fibers, carbon fibers, metal fibers, asbestos, rock wool, ceramic fibers, slag fibers, potassium titanate whiskers, boron whiskers, aluminum borate whiskers, calcium carbonate whiskers, titanium oxide whiskers, wollastonite, xonotlite, palygorskite (attapulgite), fibrous materials made of inorganic fillers such as sepiolite, heat-resistant organic fibers such as aramid fibers, polyimide fibers, PBO (polyparaphenylenebenzoxazole) fibers, and polybenzothiazole fibers, as well as fibers having a surface coating of a different material such as a metal or metal oxide.

The fibers coated with a different material may be in the form of a fiber, such as metal-coated glass fiber, metal-coated glass flakes, titanium oxide-coated glass flakes, and metal-coated carbon fiber. The method of coating the surface of the different material is not particularly limited, and examples include various known plating methods (e.g., electrolytic plating, electroless plating, hot-dip plating, etc.), vacuum deposition, ion plating, CVD (e.g., thermal CVD, MOCVD, plasma CVD, etc.), PVD, and sputtering.

Among these reinforcing fibers, it is preferable to use one type selected from glass fiber, carbon fiber, and aramid fiber, and more preferable to use at least one type selected from carbon fiber and glass fiber. Furthermore, these reinforcing fibers may be used alone or in combination.

The thickness, or fineness, of the reinforcing fibers is preferably 3 to 20 μm in average diameter, and more preferably 5 to 15 μm. In this range, not only are the physical properties of the fibers high, but they also have excellent dispersibility in the thermoplastic resin that ultimately becomes the matrix. From the standpoint of productivity, it is also preferable that the reinforcing fibers are bundles of 1,000 to 50,000 single fibers.

In addition, the reinforcing fibers used in the laminate of the present invention preferably have high strength in order to ultimately reinforce the resin, and the tensile strength of the fibers is preferably 3500 MPa to 7000 MPa and the modulus is preferably 220 GPa to 900 GPa. From the viewpoint of ultimately obtaining a high-strength molded product, carbon fibers are particularly preferred as reinforcing fibers, and PAN-based carbon fibers are even more preferred.

It is preferable that the surface of the carbon fiber is oxidized to increase compatibility with the matrix resin and improve the dispersibility of the polypropylene resin and polycarbonate resin. Although the mechanism is not yet clear, oxidizing the surface of the carbon fiber increases the polarity of the surface, and the adhesion between the non-polar propylene resin and the carbon fiber decreases further. As a result, it is thought that the adhesion with the relatively highly polar polycarbonate resin improves.

The degree of oxidation treatment can be quantified by the surface oxygen concentration (O/C) on the carbon fiber. The surface oxygen concentration (O/C) on the carbon fiber is the ratio of the number of oxygen (O) and carbon (C) atoms on the fiber surface measured by X-ray photoelectron spectroscopy. It is preferable that the surface oxygen concentration (O/C) is 0.15 or more, more preferably 0.18 or more, and even more preferably 0.2 or more. If the surface oxygen concentration is less than 0.15, the adhesion between the carbon fiber and the polycarbonate resin may be insufficient, which is not preferable. The upper limit of the surface oxygen concentration is not particularly limited, but it is generally preferable that it is 0.5 or less in terms of the balance between the handleability and productivity of the carbon fiber.

The oxidation treatment method is not particularly limited, but suitable examples include (1) a method of treating carbon fibers with an acid or alkali or a salt thereof, or an oxidizing gas, (2) a method of baking fibers or fibrous carbon filler that can be converted into carbon fiber at a temperature of 700°C or higher in the presence of an inert gas containing an oxygen-containing compound, and (3) a method of subjecting carbon fibers to an oxidation treatment and then heat treating them in the presence of an inert gas.

These reinforcing fibers can be used in the laminate in either the form of long fibers or short fibers. However, from the viewpoint of reinforcing the resin, long fiber form is preferable, and conversely, from the viewpoint of making the physical properties of the resulting composite isotropic, a configuration mainly consisting of short fibers is preferable. Here, short fibers refer to discontinuous fibers that are not long fibers. When using short fibers, it is preferable that the reinforcing fiber sheet is a fiber aggregate or nonwoven fabric in which the fiber orientation has been randomized in advance.

When the reinforcing fibers are used as short fibers (discontinuous fibers), their length is preferably 300 μm or more, more preferably 3 mm or more, even more preferably 6 mm or more, and most preferably 20 mm or more. When used as short fibers, their length is preferably 100 mm or less, even more preferably 80 mm or less, and especially preferably 60 mm or less. When such fibers are used in the form of a nonwoven fabric, the strength and dimensional anisotropy are improved.

On the other hand, when reinforcing fibers are used as long fibers, they can be used in various forms such as unidirectional sheets, woven fabrics, knitted fabrics, braided cords, etc. However, from the perspective of reinforcing the strength of the final composite, it is preferable to use them as unidirectional sheets (so-called UD sheets). Alternatively, it is preferable that some or all of the reinforcing fibers are unidirectional fiber sheets or unidirectional tapes, which are used partially. When used as long fibers, a particularly preferred form is a biaxial or triaxial woven fabric. Furthermore, it is possible to partially use one or more of these fiber forms in combination.

The content of the reinforcing fibers constituting the reinforcing fiber sheet used in the present invention is 151 to 900 parts by weight, preferably 300 to 800 parts by weight, more preferably 400 to 700 parts by weight, and even more preferably 550 to 650 parts by weight, per 100 parts by weight of the total of components A and B. If the content of the reinforcing fibers is less than 151 parts by weight, the strength of the fiber-reinforced resin composite is not fully exerted, and if it exceeds 900 parts by weight, many slippages of the reinforcing fibers occur, resulting in uneven strength.
(Lamination method)
Furthermore, the laminate of the present invention can be made into a fiber-reinforced resin composite by overlapping a thermoplastic resin sheet and a reinforcing fiber sheet as described above and applying pressure at a temperature equal to or higher than the melting temperature of the thermoplastic resin constituting the thermoplastic resin sheet and lower than the heat resistance temperature of the reinforcing fiber constituting the reinforcing fiber sheet.

The weight ratio of the thermoplastic resin sheet to the reinforcing fiber sheet is preferably in the range of 45:55 to 20:80, more preferably in the range of 35:65 to 25:75. The thermoplastic resin sheet preferably has a thickness of 0.05 to 0.5 mm, more preferably 0.1 to 0.3 mm, when measured under a load of 1.25 N/ ^cm2 using a Peacock probe with a diameter of 8 mm, and preferably has a basis weight in the range of 2 to 100 g/ ^m2 . The reinforcing fiber sheet preferably has a thickness of 0.05 to 1.0 mm and a basis weight in the range of 100 to 2000 g/ ^m2 .

The laminate of the present invention is a laminate of such thin thermoplastic resin sheets and reinforcing fiber sheets, and the lamination is preferably arranged alternately, and furthermore, a thermoplastic resin sheet is arranged on the outermost surface of the front and back. The number of reinforcing fiber sheets is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 to 2. Figure 4 shows a schematic cross-sectional view of the laminate of the present invention. In Figure 4, reference numeral 5 denotes a thermoplastic resin sheet layer, and reference numeral 6 denotes a reinforcing fiber sheet layer.
<Fiber reinforced resin composite>
The fiber-reinforced resin composite of the present invention is composed of the laminate of the present invention described above. The fiber-reinforced resin composite of the present invention is obtained by pressurizing the laminate, and has a structure in which a reinforcing fiber sheet is laminated via a thermoplastic resin sheet. A part of the thermoplastic resin sheet of the laminate is impregnated into the reinforcing fiber sheet, but basically has a cross-sectional shape similar to that of the laminate. Figure 5 shows a schematic diagram of a cross-sectional view of the fiber-reinforced resin composite of the present invention. In Figure 5, reference numeral 5 denotes a thermoplastic resin sheet layer, and reference numeral 6 denotes a reinforcing fiber sheet layer.
<Method of manufacturing fiber reinforced resin composite>
The fiber-reinforced resin composite of the present invention can be obtained by pressure-treating the laminate of the present invention. Specifically, the laminate can be produced by pressure-treating the laminate at a temperature equal to or higher than the melting temperature of the thermoplastic resin constituting the thermoplastic resin sheet and lower than the heat resistance temperature of the reinforcing fiber constituting the reinforcing fiber sheet.

With this method, the reinforcing fibers are surrounded by the thermoplastic resin, and it is preferable that no voids exist in order to improve the physical properties of the composite. The temperature for the pressure treatment depends on the thermoplastic resin used, but is preferably in the range of 200 to 340°C, and more preferably 240 to 330°C. The treatment time is preferably about 1 to 30 minutes, more preferably about 1 to 10 minutes, and particularly preferably in the range of 3 to 10 minutes. The pressing pressure during processing is preferably in the range of 2 to 30 MPa, and more preferably 5 to 20 MPa.

The present inventors currently consider the best form of the present invention to be one that incorporates the preferred ranges of each of the above-mentioned requirements, and representative examples are described in the following examples. Of course, the present invention is not limited to these forms.

Examples and Comparative Examples of the present invention will now be described in detail, but the present invention is not limited thereto. The measurement items in the examples were measured by the following methods.
(I) Evaluation of Thermoplastic Resin Sheet (I-1) Basis Weight (in the case of fibrous sheet)
Measurement was carried out in accordance with JIS L 1913.
(I-2) Degree of irregularity (in the case of fibrous sheet)
The ratio (D1/D2) of the circumscribing circle diameter D1 to the inscribing circle diameter D2 of the single fiber cross section shown in Fig. 3 was calculated and used as the irregularity. The irregularity was expressed as the average irregularity of 20 fibers.
(I-3) Hollow ratio (in the case of fibrous sheet)
The cross-sectional area (including the hollow portion) and the area of the hollow portion were measured using an image analysis system, Pierce-2 (manufactured by Pierce Co., Ltd.) of the digitized fiber cross-section photograph, and the hollow ratio (%) was calculated from the area ratio. The hollow ratio was expressed as the average hollow ratio of 20 fibers.
(I-4) Average thickness (in the case of film-like sheet)
The thickness was measured using a Peacock probe with a diameter of 8 mm under a load of 1.25 N/ ^cm2 . Measurements were taken at three points, namely, both ends and the center of the film, and the average of these measurements was taken as the average thickness.
(II) Evaluation of Laminates and Fiber-Reinforced Resin Composites (II-1) Moldability The laminates obtained in the Examples and Comparative Examples were inserted into a preheated hot press, and the moldability was evaluated according to the following criteria when molding a fiber-reinforced resin composite at a press pressure of 15 MPa under conditions of a temperature of 250°C and a press time of 10 minutes.

○: No gas generation during molding, resulting in a molded product with good surface appearance △: Some gas generation during molding, but no effect on surface appearance ×: A lot of gas generation during molding, resulting in a molded product with poor surface appearance (II-2) Number of voids The laminates obtained in the examples and comparative examples were inserted into a preheated hot press to obtain fiber-reinforced resin composites under the conditions (temperature, press time, press pressure) shown in Tables 3 to 5. The cross section of the obtained fiber-reinforced resin composite was observed at a magnification of 100 times with a scanning electron microscope (SEM, JEOL, JSM-6100), and the number of voids was evaluated by the number of bubbles in the cross section. The size of the bubbles was counted as bubbles larger than the diameter of the reinforcing fibers, and if the number was 3 or less, the impregnation of the resin into the reinforcing fibers was good.
(II-3) Flexural modulus The laminates obtained in the examples and comparative examples were inserted into a preheated hot press, and fiber-reinforced resin composites were obtained under the conditions (temperature, press time, press pressure) shown in Tables 3 to 5. Sample pieces with a length of 80 mm and a width of 10 mm were cut out from the obtained fiber-reinforced resin composites, and the flexural modulus was measured in accordance with ISO178 (measurement conditions: test speed 2 mm/min, test temperature 23° C.). The sample pieces were cut out in two directions perpendicular to each other, and the flexural modulus was evaluated as the average value of the flexural modulus in the two directions.
(II-4) Bending strength Sample pieces were prepared from the laminates obtained in the examples and comparative examples in the same manner as in (II-2), and bending strength was measured in accordance with ISO 178 (measurement conditions: test speed 2 mm/min, test temperature 23° C.). The sample pieces were cut out in two directions perpendicular to each other, and the bending strength was evaluated as the average value of the bending strength in the two directions.
(II-5) Appearance Sample pieces similar to the laminates (II-2) obtained in the Examples and Comparative Examples were prepared, and the samples were visually inspected and evaluated according to the following criteria.

〇: The fibers are evenly layered and the surface appearance is good.

△: Some fibers are unevenly layered, but this does not affect the surface appearance.

x: The fibers are unevenly laminated, and the surface appearance is poor.
[Composition used]
In the examples, the following ingredients were used:
(Component A) (Polypropylene resin)
A-1: Homopolypropylene resin ["VS200A" manufactured by Sunallomer Co., Ltd., MFR (230°C, 2.16 kg load) = 0.5 g/10 min]
A-2: Homopolypropylene resin [Prime Polypro J105G manufactured by Prime Polymer Co., Ltd., MFR (230 ° C, 2.16 kg load) = 9 g / 10 min]
(Component B) (Polycarbonate resin)
B-1: Polycarbonate resin consisting of 2,2-bis(4-hydroxyphenyl)propane as a monomer component [MVR (300° C., 1.2 kg load)=8.5 cm ³ /10 min]
B-2: A copolymeric polycarbonate resin consisting of 2,2-bis(4-hydroxyphenyl)propane as a monomer component and a polydiorganosiloxane compound represented by the following formula [14] (average repeat number p in the formula: about 37) [MVR (300° C., 1.2 kg load)=5.5 cm ³ /10 min, polydiorganosiloxane component content: 8.2%]

(Component C: Modified polyolefin resin)
C-1: Maleic anhydride modified polypropylene resin [manufactured by Mitsubishi Chemical Corporation, "SCONA TPPP 9212GA" (product name)]
C-2: Acid-modified olefin wax, which is a copolymer of maleic anhydride and α-olefin [product name "Diacarna DC30M" manufactured by Mitsubishi Chemical Corporation]
(Component D: styrene-based thermoplastic elastomer)
D-1: Styrene-ethylene propylene-styrene block copolymer [styrene content: 65 wt%, MFR: 0.4 g/10 min, Septon 2104 (product name) manufactured by Kuraray Co., Ltd.]
(Reinforcing Fiber)
FI-1: Carbon fiber unidirectional tape ["F-22" manufactured by Toho Tenax Co., Ltd., fiber diameter = 7 μm]
FI-2: Carbon fiber woven fabric ["W3101" manufactured by Toho Tenax Co., Ltd., basis weight = 200 g/m ² , thickness = 0.25 mm, fiber diameter = 7 μm]
FI-3: Nickel-coated carbon fiber tape ["HTS40 MC" manufactured by Toho Tenax Co., Ltd., fiber diameter = 7.5 μm, width = 10 mm]
FI-4: Glass fiber woven fabric ["WF150" manufactured by Nittobo Co., Ltd., basis weight = 144 g/m ² , thickness = 0.22 mm, fiber diameter = 13 μm]
FI-5: Aramid fiber nonwoven fabric ["Technora EF200" manufactured by Teijin Limited, basis weight = 200 g/m ² , fiber diameter = 12 μm]
FI-6: Carbon fiber sheet [Toho Tenax Co., Ltd.: HT C422 6 mm, long diameter 7 μm, cut length 6 mm carbon fiber compressed into a sheet of 300 mm wide and 300 mm long]
[Production Examples 1 to 9, 11 to 14] (Production of sheets made of thermoplastic resin fibers)
The polypropylene resin composition shown in Table 1 was dried in a hot air circulation dryer at 80° C. for 5 hours, and then melt-mixed with nitrogen gas as a foaming agent (nitrogen charging pressure = 3 MPa), extruded from a twin-screw extruder at the extrusion temperature shown in the table, and taken up at the spinning speed shown in the table while quenching at the die outlet, and wound up as a hollow mesh fiber sheet. The evaluation of this hollow mesh fiber sheet is shown in Table 1.
[Production Example 10] (Production of thermoplastic resin sheet (film-like))
The polypropylene resin composition shown in Table 1 was dried in a hot air circulation dryer at 80° C. for 5 hours, extruded from a twin-screw extruder at the extrusion temperature shown in the table, and quenched at the die outlet to produce a film-like thermoplastic resin sheet having the thickness shown in the table. The evaluation of this film-like sheet is shown in Table 1.
[Production Example 15]
The polypropylene resin composition shown in Table 1 was dried at 80°C for 5 hours in a hot air circulation dryer, and then melt-mixed with nitrogen gas as a foaming agent (nitrogen charging pressure = 3 MPa), extruded from a twin-screw extruder at the extrusion temperature shown in the table, and taken up at the spinning speed shown in the table while quenching at the die outlet, and wound up as a hollow mesh fiber sheet. Seven of the obtained hollow mesh fiber sheets were stacked and sent out by a belt, and while holding both ends, they were stretched in the transverse direction at a stretch ratio of 7 times, then subjected to a heat treatment at 150°C and wound up. The evaluation of this hollow mesh fiber sheet is shown in Table 1.
[Examples 1 to 18, Comparative Examples 1 to 6]
The thermoplastic resin sheets and reinforcing fiber sheets obtained in Production Examples 1 to 15 were laminated in the ratios shown in Tables 2 and 3 to form laminates.

The laminate was inserted into a preheated hot press to obtain a fiber-reinforced resin composite (FRP molded body) under the pressing conditions (temperature, pressing time, pressing pressure) shown in Tables 2 and 3. Care was taken to prevent the reinforcing fibers from becoming biased during lamination, and the amount of thermoplastic fiber sheet and reinforcing fibers was adjusted in advance so that the thickness of the fiber-reinforced resin composite would be the desired thickness after heating and pressing. The evaluation of the final fiber-reinforced resin composite is shown in Tables 2 and 3.

1. Profile fiber cross section 2. Air bubble 3. Circumscribing circle 4. Inscribing circle 5. Thermoplastic resin sheet layer 6. Reinforcing fiber sheet layer

Claims (9)

A laminate of a reinforcing fiber sheet and a thermoplastic resin sheet, wherein the thermoplastic resin sheet is a resin composition containing 0.1 to 900 parts by weight of (C) a modified polyolefin resin (component C) per 100 parts by weight of a resin component consisting of (A) 1 to 99 parts by weight of a polypropylene resin (component A) and (B) 99 to 1 part by weight of a polycarbonate resin consisting of 2,2-bis(4-hydroxyphenyl)propane as a monomer component , or a polycarbonate resin consisting of 2,2-bis(4-hydroxyphenyl)propane and a polydiorganosiloxane compound as monomer components (component B), and the content of the reinforcing fibers constituting the reinforcing fiber sheet is 151 to 900 parts by weight per 100 parts by weight of the resin component consisting of components A and B. 2. The laminate according to claim 1 , wherein the component C is a maleic anhydride-modified polypropylene. The laminate according to claim 1 or 2, characterized in that the resin composition constituting the thermoplastic resin sheet further contains (D) 1 to 20 parts by weight of a styrene-based thermoplastic elastomer (D component) per 100 parts by weight of the resin component consisting of the A component and the B component. 4. The laminate according to claim 1, wherein the reinforcing fiber sheet is any one of a woven or knitted fabric, a nonwoven fabric, and a unidirectional sheet. 5. The laminate according to claim 1, wherein the fiber constituting the reinforcing fiber sheet is at least one type of fiber selected from the group consisting of carbon fiber and glass fiber. 6. The laminate according to claim 5, wherein the fibers constituting the reinforcing fiber sheet are carbon fibers having a surface oxygen concentration (O/C), which is the ratio of the number of oxygen (O) atoms to the number of carbon (C) atoms on the fiber surface, of 0.15 or more as measured by X-ray photoelectron spectroscopy. 7. The laminate according to claim 1, wherein the thermoplastic resin sheet is made of a mesh-like hollow fiber. A fiber-reinforced resin composite comprising the laminate according to any one of claims 1 to 7 . A method for producing a fiber-reinforced resin composite, comprising pressurizing the laminate according to any one of claims 1 to 7 at a temperature equal to or higher than the melting temperature of the thermoplastic resin constituting the thermoplastic resin sheet and lower than the heat resistance temperature of the reinforcing fiber constituting the reinforcing fiber sheet.

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