WO2019044299A1 - Expanded beads and molded foam for producing fiber-reinforced composite, fiber-reinforced composite, and automotive component - Google Patents

Abstract

Expanded beads for producing a fiber-reinforced composite which comprise a base resin comprising an aromatic vinyl compound/(meth)acrylic acid ester/unsaturated dicarboxylic acid copolymer A and an aromatic vinyl compound/unsaturated dicarboxylic acid/unsaturated dicarboximide copolymer B, the copolymer B being contained in an amount of 1-50 wt% with respect to the sum of the copolymers A and B.

Description

Expanded particles and foams for producing fiber reinforced composites, fiber reinforced composites and automotive parts

The present invention relates to a foam particle and a foam molded article for producing a fiber-reinforced composite, a fiber-reinforced composite and an automobile part. More particularly, the present invention relates to a foam particle and a foam molded body capable of providing a fiber-reinforced composite with an improved surface aesthetics, a fiber-reinforced composite with an improved surface aesthetics and an automobile part.

In recent years, vehicles such as aircraft, automobiles, and ships are required to improve fuel efficiency to reduce the load on the global environment, and the metal materials that make up these vehicles are converted to resin materials to achieve large weight reduction. The flow is getting stronger. Fiber-reinforced plastics are mentioned as these resin materials. In addition, a fiber reinforced composite in which a fiber reinforced plastic and a core material are laminated has also been proposed for the purpose of further reducing the weight and increasing the rigidity. For example, as a core material, polystyrene foam molded articles having high compressive strength have been studied (Japanese Patent Application Laid-Open No. 2012-214751: Patent Document 1).

JP 2012-214751 A

However, since the foam molded article of Patent Document 1 is made of a styrenic resin having a low glass transition temperature, mechanical properties including heat resistance are not sufficient. In order to improve mechanical properties, it is conceivable to select a resin other than styrene resin.
By the way, from the viewpoint of improving the aesthetics of the fiber reinforced surface of the fiber reinforced plastic constituting the fiber reinforced composite, it is desired to improve the smoothness.

The inventor of the present invention examined various resins as a core material in order to improve the mechanical properties of the fiber-reinforced composite, and it was found that the copolymer of aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid was used. By using a base resin containing the united substance A and the aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B, the smoothness of the fiber reinforced surface can be improved along with the improvement of the mechanical properties. The present invention has been achieved by unexpectedly finding things.

Thus, according to the present invention, a group comprising an aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B Foamed particles for producing a fiber-reinforced composite are provided, which are composed of a material resin and the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B.

Further, according to the present invention, it comprises an aromatic vinyl- (meth) acrylic acid ester-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B. There is provided a foam-molded article for producing a fiber-reinforced composite, comprising a base resin, wherein the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B.

Further, according to the present invention, it comprises an aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B. A foam molded article comprising a base resin, wherein the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B, and is integrally laminated on the surface of the foam molded article There is provided a fiber reinforced composite having a fiber reinforced plastic layer.
Further, according to the present invention, there is provided an automobile part comprising the above fiber reinforced composite.

According to the present invention, it is possible to provide a foam particle and a foam molded body capable of providing a fiber-reinforced composite having an improved surface appearance, a fiber-reinforced composite having an improved surface appearance, and an automotive part.

It is a photograph (a) and the diagram (b) of the fiber reinforced surface of the fiber reinforced composite of Example 1. FIG. It is a photograph (a) and the diagram (b) of the fiber reinforced surface of the fiber reinforced composite of Example 2. FIG. It is a photograph (a) and the diagram (b) of the fiber reinforced surface of the fiber reinforced composite of Example 3. FIG. It is a photograph (a) and the diagram (b) of the fiber reinforced surface of the fiber reinforced composite of the comparative example 1. FIG.

(Foamed particles)
Foamed particles are used for the production of a foam-molded article in a fiber-reinforced composite having a foam-molded article and a fiber-reinforced plastic layer laminated and integrated on the surface thereof.
(1) Base Material Resin Foamed particles are composed of an aromatic vinyl- (meth) acrylic acid ester-unsaturated dicarboxylic acid copolymer A (hereinafter, also simply referred to as a copolymer A) and an aromatic vinyl-unsaturated dicarboxylic acid A base resin containing an unsaturated dicarboximide copolymer B (hereinafter, also simply referred to as a copolymer B). The proportion of the total amount of the copolymers A and B in the base resin is preferably 70% by weight or more, more preferably 85% by weight or more, and 100% by weight. The base resin preferably has a glass transition temperature Tg of 115 to 160.degree. When Tg is lower than 115 ° C., the lamination integration of the fiber reinforced plastic layer on the surface of the foam molded article produced using the foamed particles is insufficient, and the mechanical properties of the fiber reinforced composite are lowered. There is. If the temperature is higher than 160 ° C., the foamability of the foam particles may be reduced, and the heat fusion and integration of the foam particles may be insufficient to reduce the mechanical properties of the fiber-reinforced composite. Tg is, for example, 115 ° C., 120 ° C., 125 ° C., 130 ° C., 135 ° C., 140 ° C., 145 ° C., 150 ° C., 155 ° C., 160 ° C. The more preferable Tg is 120 to 150 ° C.

(I) Copolymer A
(A) Aromatic Vinyl Aromatic vinyl is an aromatic compound having a substituent consisting of a vinyl group. The number of vinyl groups and the carbon number of the aromatic compound are not particularly limited. Specific aromatic vinyls include styrene-based monofunctional monomers such as styrene, α-methylstyrene, vinyltoluene, ethylstyrene, i-propylstyrene, t-butylstyrene, dimethylstyrene, bromostyrene and chlorostyrene. Divinylbenzene, trivinylbenzene, divinyltoluene, divinylxylene, bis (vinylphenyl) methane, bis (vinylphenyl) ethane, bis (vinylphenyl) propane, bis (vinylphenyl) butane, divinylnaphthalene, divinylanthracene, divinylbiphenyl, Ethylene oxide adduct of bisphenol A di (meth) acrylate, propylene oxide adduct of bisphenol A di (meth) acrylate, etc. may be mentioned. The aromatic vinyl may be used alone or in combination of two or more. Among these, styrene is preferred from the viewpoint of easy availability.

(B) (Meth) acrylic acid ester (Meth) acrylic acid ester is not particularly limited, and examples thereof include (meth) acrylic acid alkyl ester. The carbon number of the alkyl group in the (meth) acrylic acid alkyl ester can be 1 to 5. Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate and the like. The (meth) acrylic acid esters may be used alone or in combination of two or more. From the viewpoint of improving the mechanical properties of the fiber-reinforced composite, methyl (meth) acrylate is preferable, and methyl methacrylate is more preferable.

(C) Unsaturated Dicarboxylic Acid The unsaturated dicarboxylic acid is not particularly limited, and examples thereof include aliphatic unsaturated dicarboxylic acids having 2 to 6 carbon atoms. Specific unsaturated dicarboxylic acids include maleic acid, itaconic acid, citraconic acid, aconitic acid, anhydrides thereof and the like. The unsaturated dicarboxylic acids may be used alone or in combination of two or more.

(D) Ratio of units derived from aromatic vinyl, (meth) acrylic ester, unsaturated dicarboxylic acid A total of units derived from three of aromatic vinyl, (meth) acrylic ester and unsaturated dicarboxylic acid is 100 In terms of parts by weight, 30 to 80 parts by weight of units derived from aromatic vinyl, 8 to 35 parts by weight of units derived from (meth) acrylic acid ester, and 10 to 50 parts by weight of units derived from unsaturated dicarboxylic acid It is preferable to include.
If the proportion of units derived from aromatic vinyl is less than 30 parts by weight, the foamability of the foam particles is reduced during foam molding, and the heat fusion and integration of the foam particles become insufficient, resulting in a fiber reinforced composite The mechanical properties of may decrease. If this proportion is greater than 80 parts by weight, the heat resistance of the fiber-reinforced composite may be reduced. This ratio is, for example, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight is there. The proportion is more preferably 40 to 75 parts by weight, still more preferably 45 to 70 parts by weight.

If the proportion of the unit derived from the (meth) acrylic acid ester is less than 8 parts by weight, the mechanical properties of the fiber-reinforced composite may be lowered. When this ratio is larger than 35 parts by weight, the foamability of the foam particles is reduced during foam molding, and the heat fusion and integration of the foam particles is insufficient to lower the mechanical properties of the fiber reinforced composite. There is. This ratio is, for example, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, 17 parts by weight, 20 parts by weight, 22 parts by weight, 25 parts by weight, 27 parts by weight, 30 parts by weight, 33 parts by weight, 35 parts by weight. The proportion is more preferably 10 to 33 parts by weight, still more preferably 15 to 30 parts by weight.
If the proportion of units derived from unsaturated dicarboxylic acids is less than 10 parts by weight, the heat resistance of the fiber-reinforced composite may decrease. When this ratio is greater than 50 parts by weight, the foamability of the foam particles is reduced during foam molding, and the heat fusion and integration of the foam particles is insufficient to lower the mechanical properties of the fiber-reinforced composite. There is. This ratio is, for example, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, and 50 parts by weight. The proportion is more preferably 15 to 40 parts by weight, still more preferably 20 to 35 parts by weight.
The amount of the monomer used and the content of the unit derived from the monomer substantially coincide with each other.

Each component ratio, that is, the ratio of units derived from aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and further units derived from other monomers and other resins described below, ¹ It can be defined by the peak height of H-NMR or the area ratio of FT-IR. Specific measurement methods will be described in the examples.

(Ii) copolymer B
(A) Aromatic Vinyl The aromatic vinyl is not particularly limited, and examples thereof include the compounds exemplified in the above-mentioned copolymer A (a). The aromatic vinyl may be used alone or in combination of two or more. Among these, styrene is preferred from the viewpoint of easy availability.
(B) Unsaturated Dicarboxylic Acid The unsaturated dicarboxylic acid is not particularly limited, but the compounds exemplified in (c) of the above-mentioned copolymer A can be mentioned. The unsaturated dicarboxylic acids may be used alone or in combination of two or more. From the viewpoint of improving the mechanical properties of the foam molded article, maleic anhydride is preferred.

(C) Unsaturated Dicarboximide The unsaturated dicarboximide is not particularly limited, but maleimide such as maleimide, N-methyl maleimide, N-ethyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N-naphthyl maleimide and the like Examples include system monomers. The unsaturated dicarboximide derivatives may be used alone or in combination of two or more. From the viewpoint of improving the heat resistance of the fiber-reinforced composite, N-phenylmaleimide is preferable.

(D) Proportion of units derived from aromatic vinyl, unsaturated dicarboxylic acid, unsaturated dicarboximide 100 parts by weight of the total of units derived from aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboximide Assuming that 20-80 parts by weight of a unit derived from aromatic vinyl, 2-30 parts by weight of a unit derived from unsaturated dicarboxylic acid, and 20-80 parts by weight of a unit derived from unsaturated dicarboxylic acid imide preferable.
If the proportion of units derived from aromatic vinyl is less than 20 parts by weight, the foamability of the foam particles is reduced during foam molding, and heat fusion and integration of the foam particles become insufficient, resulting in a fiber reinforced composite The mechanical properties of may decrease. If this proportion is greater than 80 parts by weight, the heat resistance of the foam molded article may be reduced. This ratio is, for example, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, It is 75 parts by weight and 80 parts by weight. The proportion is more preferably 30 to 75 parts by weight, still more preferably 50 to 70 parts by weight.

(Iii) Other Monomers The copolymers A and / or B each have a further coweight with components derived from other monomers within the range not to inhibit the characteristics of the present invention other than the above three monomers. It may be combined. Examples of other monomers include (meth) acrylonitrile, dimethyl maleate, diethyl maleate, dimethyl fumarate, diethyl fumarate, ethyl fumarate, (meth) acrylic acid and the like.
The proportion of units derived from other monomers in both copolymers is preferably 30% by weight or less, and may be 0% by weight.

(Iv) Content Ratio of Copolymers A and B The copolymer B may be contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B. When the content of the copolymer B is less than 1% by weight, the effect of improving the beauty of the surface of the fiber-reinforced composite may be low. If it is more than 50% by weight, the brittleness may be high and the foam may be buckled at the time of preparation of the fiber-reinforced composite. The content of copolymer B is, for example, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% , 50% by weight. The content of the copolymer B is preferably 5 to 40% by weight.

(V) Other Resins Other resins may be mixed with the base resin. Other resins include rubber-modified rubbers to which a diene rubber-like polymer such as polyolefin resin such as polyethylene and polypropylene, polybutadiene, styrene-butadiene copolymer, and ethylene-propylene-nonconjugated diene three-dimensional copolymer are added Impact-resistant polystyrene resin, polycarbonate resin, polyester resin, polyamide resin, polyphenylene ether, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polymethyl methacrylate etc., styrene- (meth) acrylic acid copolymer And styrene- (meth) acrylic acid ester copolymers, aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymers, and the like.

Among the above-mentioned other resins, the foamed particles may contain polymethyl methacrylate. By containing polymethyl methacrylate, the heat-sealing property of the foam particles is improved, and the foam particles are more firmly heat-fused and integrated to form a foam molded article having further excellent mechanical properties. You can get it. The content of poly (methyl methacrylate) in the expanded particles is preferably 10 to 500 parts by weight, more preferably 20 to 450 parts by weight, and particularly preferably 30 to 400 parts by weight with respect to 100 parts by weight of the copolymer.

The expanded particles may contain an acrylic resin as a processing aid. By containing the processing aid, the melt tension (viscoelasticity) at the time of foaming of the resin constituting the foamed particles is made suitable for foaming, and the open celling of the foamed particles is suppressed, and the foamed particles are foamed. It is possible to improve the property, to strengthen the heat fusion of the foam particles to each other, and to produce a foam molded product having further excellent mechanical properties. The content of the processing aid in the foamed particles is preferably 0.5 to 5 parts by weight, and more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the copolymer.

The acrylic resin as a processing aid is not particularly limited, and contains 50% by weight or more of a homopolymer of an acrylic monomer or a copolymer of two or more of these, and an acrylic monomer Examples thereof include copolymers of acrylic monomers and vinyl monomers copolymerizable therewith. Examples of acrylic monomers include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like. Examples of the vinyl monomer copolymerizable with the acrylic monomer include α-methylstyrene, acrylonitrile and the like. The weight average molecular weight of the acrylic resin is preferably 1.5 million to 6 million, more preferably 2 million to 4.5 million, and particularly preferably 2.5 million to 4 million. Even if the weight average molecular weight of the acrylic resin is too low or too high, it is difficult to sufficiently adjust the melt tension (viscoelasticity) at the time of foam molding of the resin constituting the foamed particles to one suitable for foaming, and foaming It may not be possible to improve the foamability of the particles.

(Vi) Additives In the base resin, additives may be contained in addition to the resin, as necessary. Additives include plasticizers, flame retardants, flame retardant aids, antistatic agents, spreading agents, cell regulators, fillers, colorants, weathering agents, anti-aging agents, lubricants, anti-fogging agents, perfumes, etc. It can be mentioned.

(2) Configuration The average particle size of the foamed particles is preferably 500 to 5000 μm, and more preferably 1000 to 3000 μm. The average particle size is, for example, 500 μm, 1000 μm, 2000 μm, 3000 μm, 4000 μm, 5000 μm.
The outer shape of the foamed particles is not particularly limited as long as the foamed molded article can be produced, and examples thereof include spherical, substantially spherical, cylindrical and the like. The expanded particles preferably have an outer shape represented by an average aspect ratio of 0.8 or more (the upper limit is a true sphere of 1). The aspect ratio is, for example, 0.8, 0.85, 0.9, 0.95, 1.

The expanded particles preferably have a bulk multiple of 20 to 1.4 times. If the bulk ratio is more than 20 times, the open cell rate of the foamed particles may be increased, and the foamability of the foamed particles may be reduced at the time of foaming of the foam molding. If it is smaller than 1.4 times, the cells of the foamed particles may become nonuniform, and the foamability of the foamed particles may be insufficient at the time of foam molding. The bulk factor is, for example, 20 times, 18 times, 14 times, 12.5 times, 10 times, 5 times, 2 times, 1.6 times, 1.4 times. The bulk ratio is more preferably 14 to 1.6 times, particularly preferably 12.5 to 2 times.
The foamed particles preferably exhibit an open cell ratio of 40% or less. If the open cell ratio is higher than 40%, the foaming pressure of the foamed particles may be insufficient at the time of foam molding, and the heat fusion and integration of the foamed particles may be insufficient to reduce the mechanical properties of the fiber reinforced composite. is there. The open cell rate is, for example, 40%, 35%, 30%, 20%, 10%, 5%, 0%. The open cell rate is more preferably 35% or less.

(3) Manufacturing Method As a method of manufacturing the foamed particles, there is a method of impregnating resin particles with a foaming agent in the gas phase to obtain expandable particles, and expanding the expandable particles.
First, as a method of producing resin particles,
(I) A method of manufacturing by melting and kneading a raw material resin (a mixture of constituent resins of a base resin) in an extruder, cutting the kneaded material out while extruding it from a nozzle mold attached to the extruder, and cooling it.
(Ii) The raw material resin is melt-kneaded in an extruder, and the kneaded material is extruded from a nozzle mold attached to the extruder and then cooled to obtain a strand, and the strand is cut at predetermined intervals. ,
(Iii) The raw material resin is melt-kneaded in an extruder, and the kneaded product is extruded from an annular die or a T-die attached to the extruder to produce a sheet, and the sheet is cut to produce a method. In addition, a bubble control agent may be supplied to the extruder. Examples of the cell regulator include polytetrafluoroethylene powder, polytetrafluoroethylene powder modified with an acrylic resin, and talc. The amount of the cell regulator is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the resin composition. When the amount of the cell regulator is less than 0.01 weight, the cells of the foamed particles become coarse, and the appearance of the resulting foam molded article may be deteriorated. When the amount is more than 5 parts by weight, the closed cell rate of the foamed particles may be reduced due to the cell rupture. The amount of the cell regulator is more preferably 0.05 to 3 parts by weight, and particularly preferably 0.1 to 2 parts by weight.

Next, as a method for producing the expandable particles, there is mentioned a method of impregnating resin particles with a foaming agent in a gas phase in a container which can be sealed. As the foaming agent, saturated aliphatic hydrocarbons such as propane, normal butane, isobutane, normal pentane, isopentane and hexane, ethers such as dimethyl ether, methyl chloride, 1,1,1,2-tetrafluoroethane, 1,1 Inorganic gases such as fluorocarbons such as 1-difluoroethane and monochlorodifluoromethane, carbon dioxide and nitrogen. Among them, dimethyl ether, propane, normal butane, isobutane and carbon dioxide are preferable, propane, normal butane and isobutane are more preferable, and normal butane and isobutane are particularly preferable. The blowing agents may be used alone or in combination of two or more.

If the amount of the blowing agent introduced into the container is too small, the foam particles may not be able to foam to a desired expansion ratio. When the amount of the foaming agent is too large, since the foaming agent acts as a plasticizer, the visco-elasticity of the base resin is excessively lowered, the foaming property may be lowered, and good foamed particles may not be obtained. Accordingly, the amount of the foaming agent is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 4 parts by weight, and particularly preferably 0.3 to 3 parts by weight with respect to 100 parts by weight of the raw material resin.
Furthermore, as a method of producing the foamed particles, a method of heating with a heating medium such as water vapor in a sealable container can be mentioned. The heating conditions include, for example, a gauge pressure of 0.3 to 0.5 MPa, a temperature of 120 to 159 ° C., and a time of 10 to 180 seconds.
The particle size of the foamed particles can be varied by changing the diameter of the multi-nozzle mold attached to the front end of the extruder.

(Foam molded body)
(1) Base resin The foamed molded article is composed of a base resin containing the copolymers A and B, and the copolymer B is 1 to 50% by weight with respect to the total of the copolymers A and B. included. The content of copolymer B is, for example, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% , 50% by weight. The base resin that constitutes the foam molded body is the same as the base resin of the above-described foam particles.
(2) Physical Properties The average particle diameter of the fused foamed particles constituting the foamed molded article is preferably 600 to 6000 μm, and more preferably 1200 to 3600 μm. The average particle size is, for example, 600 μm, 1200 μm, 2000 μm, 3000 μm, 3600 μm, 6000 μm.
The outer shape of the fused foam particles is not particularly limited as long as the foam can be maintained.

The foam molding preferably has a multiple of 20 to 1.4. If the ratio is more than 20 times, mechanical properties may be insufficient. If it is less than 1.4 times, the advantage of foaming may be reduced due to the increase in weight. The bulk factor is, for example, 20 times, 18 times, 14 times, 12.5 times, 10 times, 5 times, 2 times, 1.6 times, 1.4 times. The multiple is more preferably 14 to 1.6, and particularly preferably 12.5 to 2.
The foam molded body preferably exhibits an open cell rate of 40% or less. If the open cell rate is higher than 40%, the mechanical properties of the fiber reinforced composite may be degraded. The open cell rate is, for example, 40%, 35%, 30%, 20%, 10%, 5%, 0%. The open cell rate is more preferably 35% or less.
The heating dimensional change rate at 120 ° C. of the foamed molded article is preferably −1 to 1%. The foamed molded article can be suitably used for applications under a high temperature environment because its heating dimensional change rate is -1 to 1%. The heating dimensional change rate is, for example, -1%, -0.07%, -0.05%, 0%, 0.05%, 0.07%, 1%.
The flexural modulus per unit density in the foam molded article is preferably 600 MPa / (g / cm ³ ) or more. If the flexural modulus is too low, the pressure applied when laminating and integrating a skin material such as fiber reinforced plastic on the surface of the foam molded body may cause deformation of the foam molded body. The bending elastic modulus is, for example, 600, 800, 1000, 1200, 1400 (unit abbreviation).

(3) Manufacturing Method As a method of manufacturing a foam molded article, foam particles were filled in a cavity of a mold, a heating medium was supplied into the cavity, and the foam particles were heated to refoam and refoam. There is a method of obtaining a foam molded article by thermally fusing and integrating foam particles with each other by the foaming pressure. As a heating medium, water vapor | steam, a hot air, warm water etc. are mentioned, for example, Water vapor | steam is preferable.

(Fiber-reinforced composite)
The fiber reinforced composite has a foam molded body and a fiber reinforced plastic layer laminated and integrated on the surface thereof. The foamed molded product is composed of a base resin containing the copolymers A and B, and the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B. The base resin that constitutes the foam molded body is the same as the base resin of the above-described foam particles.
When the foam molded body is a foam sheet, it is not necessary to laminate and integrate on both sides of the foam molded body, as long as fiber reinforced plastic is laminated and integrate on at least one surface of both sides of the foam molded body. . The lamination of fiber reinforced plastic may be determined depending on the application of the reinforced composite. Among them, in consideration of the surface hardness and mechanical strength of the reinforced composite, it is preferable that fiber reinforced plastics be integrally laminated on both surfaces in the thickness direction of the foam molded article.

Reinforcing fibers constituting the fiber reinforced plastic include inorganic fibers such as glass fiber, carbon fiber, silicon carbide fiber, alumina fiber, tyranno fiber, basalt fiber, and ceramic fiber; metal fibers such as stainless steel fiber and steel fiber; aramid Organic fibers such as fibers, polyethylene fibers, poly-p-phenylene benzoxador (PBO) fibers, etc .; and boron fibers. The reinforcing fibers may be used alone or in combination of two or more. Among them, carbon fiber, glass fiber and aramid fiber are preferable, and carbon fiber is more preferable. These reinforcing fibers have excellent mechanical properties despite being lightweight.

The reinforcing fibers are preferably used as a reinforcing fiber base processed into a desired shape. Examples of the reinforcing fiber base include woven fabrics, knitted fabrics, non-woven fabrics made of reinforcing fibers, and facing materials made by binding (suture) fiber bundles (strands) in which reinforcing fibers are aligned in one direction with yarn. . The weave of the woven fabric includes plain weave, twill weave, satin weave and the like. The yarns include synthetic resin yarns such as polyamide resin yarns and polyester resin yarns, and stitch yarns such as glass fiber yarns.
The reinforcing fiber base may be used without laminating only one reinforcing fiber base, or may be used as a laminated reinforcing fiber base by laminating a plurality of reinforcing fiber bases. As a laminated reinforcing fiber base in which a plurality of reinforcing fiber bases are laminated, (1) a laminated reinforcing fiber base in which only one type of reinforcing fiber base is prepared and these reinforcing fiber bases are laminated, 2) A multi-layered reinforcing fiber base prepared by laminating a plurality of types of reinforcing fiber base, and (3) a fiber bundle (strand) obtained by aligning the reinforcing fibers in one direction is bound with a yarn (y) A plurality of reinforcing fiber substrates formed by stitching are prepared, and these reinforcing fiber substrates are superimposed so that the fiber directions of the fiber bundles are directed in different directions, and the superimposed reinforcing fiber substrates are yarns The laminated reinforcing fiber base material etc. which are united (sutured) are used.

The fiber reinforced plastic is obtained by impregnating a reinforced fiber with a synthetic resin. Reinforcing fibers are bound and integrated by the impregnated synthetic resin.
The method for impregnating the reinforcing fiber with the synthetic resin is not particularly limited, and examples thereof include (1) a method of immersing the reinforcing fiber in the synthetic resin, and (2) a method of applying the synthetic resin to the reinforcing fiber.
As a synthetic resin to be impregnated into the reinforcing fiber, any of a thermoplastic resin or a thermosetting resin can be used, and a thermosetting resin is preferably used. The thermosetting resin to be impregnated into the reinforcing fiber is not particularly limited, and epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicone resin, maleimide resin, vinyl ester resin, cyanate ester resin, maleimide The resin etc. which carried out the prepolymerization of resin and cyanate ester resin etc. are mentioned, Since it is excellent in heat resistance, impact absorption property, or chemical resistance, an epoxy resin and vinyl ester resin are preferable. The thermosetting resin may contain additives such as a curing agent and a curing accelerator. In addition, a thermosetting resin may be used independently and 2 or more types may be used together.

Further, the thermoplastic resin to be impregnated into the reinforcing fiber is not particularly limited, and an olefin resin, a polyester resin, a thermoplastic epoxy resin, an amide resin, a thermoplastic polyurethane resin, a sulfide resin, an acrylic resin and the like are mentioned. And polyester resins and thermoplastic epoxy resins are preferable because they are excellent in adhesion to a foam molded article or adhesion between reinforcing fibers constituting a fiber reinforced plastic. In addition, a thermoplastic resin may be used independently and 2 or more types may be used together.
The thermoplastic epoxy resin is a polymer or copolymer of epoxy compounds and has a linear structure, or a copolymer of an epoxy compound and a monomer that can be polymerized with the epoxy compound. Copolymers having a straight chain structure. Specifically, as the thermoplastic epoxy resin, for example, bisphenol A type epoxy resin, bisphenol fluorene type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, cyclic aliphatic type epoxy resin, long chain aliphatic type resin An epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin etc. are mentioned, A bisphenol A type epoxy resin and a bisphenol fluorene type epoxy resin are preferable. The thermoplastic epoxy resin may be used alone or in combination of two or more.

As a thermoplastic polyurethane resin, the polymer which has a linear structure obtained by polymerizing diol and diisocyanate is mentioned. Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol and the like. The diols may be used alone or in combination of two or more. Examples of the diisocyanate include aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates. The diisocyanate may be used alone or in combination of two or more. The thermoplastic polyurethane resin may be used alone or in combination of two or more.
The content of the synthetic resin in the fiber reinforced plastic is preferably 20 to 70% by weight. If the content is less than 20% by weight, the binding properties between the reinforcing fibers and the adhesion between the fiber reinforced plastic and the foamed molded article become insufficient, and the mechanical properties of the fiber reinforced plastic and the mechanical strength of the fiber reinforced composite May not improve enough. If it is more than 70% by weight, the mechanical properties of the fiber-reinforced plastic may be reduced, and the mechanical strength of the fiber-reinforced composite may not be sufficiently improved. The content is more preferably 30 to 60% by weight.

The thickness of the fiber reinforced plastic is preferably 0.02 to 2 mm, more preferably 0.05 to 1 mm. Fiber reinforced plastics having a thickness in this range are excellent in mechanical properties despite being lightweight.
Basis weight of the fiber-reinforced plastics, preferably 50 ~ 4000g / m ^2, more preferably 100 ~ 1000g / m ^2. Fiber reinforced plastics having a weight per unit area within this range are excellent in mechanical properties despite being lightweight.

Next, a method of producing a reinforced composite will be described. The method for producing a reinforced composite by laminating and integrating fiber reinforced plastic on the surface of a foam molded article is not particularly limited. For example, (1) fiber reinforced plastic is bonded to the surface of the foam molded body via an adhesive. Method of laminating and integrating (2) A fiber-reinforced plastic forming material obtained by impregnating a reinforcing fiber with a thermoplastic resin is laminated on the surface of a foam molded body, and foaming is performed using the thermoplastic resin impregnated in the reinforcing fiber as a binder A method of integrally laminating a fiber reinforced plastic forming material as a fiber reinforced plastic on the surface of a molded body, (3) A fiber reinforced plastic forming material in which a reinforcing fiber is impregnated with an uncured thermosetting resin on the surface of a foam molded body Of a fiber-reinforced plastic formed by curing a thermosetting resin using a thermosetting resin impregnated in reinforcing fibers as a binder (4) A fiber reinforced plastic is required by placing the fiber reinforced plastic in a heated and softened state on the surface of the foam molded body and pressing the fiber reinforced plastic against the surface of the foam molded body According to the method, a method of laminating and integrating on the surface of the foam molded body while being deformed along the surface of the foam molded body, (5) a method generally applied in the molding of fiber reinforced plastic, and the like can be mentioned.

Examples of methods used for molding fiber reinforced plastics include autoclave method, hand lay up method, spray up method, PCM (Prepreg Compression Molding) method, RTM (Resin Transfer Molding) method, VaRTM (Vacuum assisted Resin Transfer Molding) Law etc. are mentioned.

The fiber-reinforced composite thus obtained is excellent in heat resistance, mechanical strength and lightness, and has a fiber-reinforcing surface with improved aesthetics. Therefore, it can be used in a wide range of applications such as the fields of transportation equipment such as automobiles, aircrafts, railway cars and ships, home appliances, information terminals, and furniture. Here, the fiber reinforced surface with improved aesthetics can be evaluated by its surface smoothness. The surface smoothness is preferably 10% or less. The surface smoothness is, for example, 0%, 1%, 3%, 5%, 7%, 10%.
For example, fiber reinforced composites are parts of transportation equipment and parts for transportation equipment construction (especially parts for automobiles) including structural parts that constitute the main body of transportation equipment, wind turbine blades, robot arms, cushioning materials for helmets, It can be suitably used as a transport container such as an agricultural product box, a heat insulation cold storage container, a rotor blade of an industrial helicopter, and a parts packing material.

According to the present invention, there is provided an automotive component comprising the fiber-reinforced composite of the present invention, such as a floor panel, roof, bonnet, fender, undercover, wheel, steering wheel, etc. Examples include parts such as containers (housings), hood panels, suspension arms, bumpers, sun visors, trunk lids, luggage boxes, seats, doors, and cowls.

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention in any way. First, evaluation methods of the example and the comparative example will be described.
(Glass-transition temperature)
The glass transition temperature was measured by the method described in JIS K 7121: 1987 "Transition temperature measurement method of plastic". However, the sampling method and temperature conditions were as follows.
About 6 mg of a sample was packed using a differential scanning calorimeter DSC2220 (manufactured by SII Nano Technology Inc.) so that the bottom of the aluminum measurement container was not separated. The sample was heated from 30 ° C. to 220 ° C. at a heating rate of 20 ° C./min under a nitrogen gas flow rate of 20 mL / min. After holding for 10 minutes, the sample is taken out immediately and allowed to cool in an environment of 25 ± 10 ° C, and then the DSC curve obtained when the temperature is raised from 30 ° C to 220 ° C at a temperature rising rate of 20 ° C / min. The glass transition temperature (starting point) was calculated. At this time, alumina was used as a reference material. The glass transition start temperature was determined from the standard (9.3 “How to Determine Glass Transition Temperature”).

(Bulk density and bulk multiple)
The bulk density was measured in accordance with JIS K 6911: 1995 “Thermosetting plastic general test method”. That is, it measured using the apparent density measuring device based on JISK6911, and measured the bulk density based on the following formula.
Bulk density of foamed particles (g / cm ³ ) = [weight of measuring cylinder containing sample (g) -weight of measuring cylinder (g)] / [volume of measuring cylinder (cm ³ )]
The bulk multiple was a value obtained by integrating the resin density to the reciprocal of the bulk density.

(Density and multiples)
The weight (a) and the volume (b) of the test piece (example 75 × 300 × 30 mm) cut out from the foam molded article are measured so as to have three or more significant figures, respectively, and the foam is produced by the formula (a) / (b) The density (g / cm ³ ) of the compact was determined.
The multiple is a value obtained by integrating the resin density to the reciprocal of the density.

(FT-IR)
The absorbance ratio (D1780 / D698, D1720 / D698) of the base resin was measured in the following manner.
An infrared absorption spectrum was obtained by performing surface analysis on each of ten randomly selected resin particles by infrared spectroscopy ATR measurement method. In this analysis, an infrared absorption spectrum in the range of several μm (about 2 μm) in depth from the sample surface was obtained. The absorbance ratio (D1780 / D698, D1720 / D698) was calculated from each infrared absorption spectrum, and the arithmetic mean of the calculated absorbance ratio was defined as the absorbance ratio.
Absorbance D1780, D1720 and D698 are obtained by connecting “Smart-iTR” manufactured by Thermo SCIENTIFIC as an ATR accessory to a measuring apparatus sold by Thermo SCIENTIFIC under the trade name “Fourier Transform Infrared Spectrophotometer Nicolet iS10”. It was measured. Infrared spectroscopy ATR measurement was performed under the following conditions.

<Measurement conditions>
Measurement device: Fourier transform infrared spectrophotometer Nicolet iS10 (manufactured by Thermo SCIENTIFIC) and one-reflection-type horizontal ATR Smart-iTR (manufactured by Thermo SCIENTIFIC)
ATR crystal: Diamond with ZnSe lens, angle = 42 °
・ Measurement method: One-time ATR method ・ Measurement wave number domain: 4000 cm ^-1 to 650 cm ^-1
・ Wavenumber dependence of measurement depth: not corrected ・ Detector: Deuterated triglycine sulfate (DTGS) detector and KBr beam splitter ・ Resolution: 4 cm ^-1
・ Number of integrations: 16 times (same for background measurement)
In the ATR method, the intensity of the infrared absorption spectrum obtained by measurement changes depending on the degree of adhesion between the sample and the high refractive index crystal, so the degree of adhesion is almost uniform by applying the maximum load applied by "Smart-iTR" of the ATR accessory The measurement was performed.

The infrared absorption spectrum obtained under the above conditions was subjected to peak processing as follows to obtain each of D1780, D1720 and D698.
The absorbance D1780 at 1780 cm ^-1 obtained from the infrared absorption spectrum was the absorbance corresponding to the absorption spectrum derived from the antisymmetric stretching vibration by C = O of the two carbonyl groups in maleic anhydride.
In this measurement of absorbance, no peak separation was performed even when other absorption spectra overlapped at 1780 cm ^-1 . Absorbance D1780 is a straight line connecting the 1920Cm ^-1 and 1620 cm ^-1 as a baseline, and mean maximum absorbance between 1810 cm ^-1 and 1745 cm ^-1.

Further, the absorbance D1720 at 1720 cm ^-1 was an absorbance corresponding to the absorption spectrum derived from the anti-symmetrical stretching vibration by the carbonyl group C = O contained in methyl methacrylate.
In this measurement of absorbance, no peak separation was performed even when other absorption spectra overlapped at 1720 cm ^-1 . Absorbance D1720 is a straight line connecting the 1920Cm ^-1 and 1620 cm ^-1 as a baseline, and mean maximum absorbance between 1745 cm ^-1 and 1690 cm ^-1.

The absorbance D698 at 698 cm ^-1 was taken as the absorbance corresponding to the absorption spectrum derived from the out-of-plane bending vibration of CH in the monosubstituted benzene ring in styrene.
In this measurement of absorbance, no peak separation was performed even when other absorption spectra overlapped at 698 cm ^-1 . Absorbance D698 is a straight line connecting the 1510 cm ^-1 and 810 cm ^-1 as a baseline, and mean maximum absorbance between 720 cm ^-1 and 660 cm ^-1.

The styrene, methyl methacrylate and maleic anhydride ratio (% by mass) was calculated from the absorbance ratio (D1780 / D698, D1720 / D698) based on a calibration curve described later. In addition, the peak processing method used the method similar to the above-mentioned resin particle.
As a method of determining the composition ratio of styrene and methyl methacrylate from the absorbance ratio, a plurality of types of standard samples were prepared by uniformly mixing a styrene resin and methyl methacrylate resin at a predetermined composition ratio.
Specifically, the monomers obtained by measuring methyl methacrylate and styrene at weight ratios of 0/100, 20/80, 40/60, 50/50 and 60/40, respectively, are placed in a 10 ml screw vial, The monomer was dissolved by adding 10 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) to 100 parts by weight of the monomer. The obtained mixed solution was transferred to a 2 ml sample tube (φ 7 mm × 122 mm × 190 mm), purged with nitrogen and sealed. Next, this was placed in a water bath set at 65 ° C., and heating was carried out for 10 hours to complete the polymerization, and the polymer taken out from the ampoule was used as a standard sample.
For each standard sample, an infrared absorption spectrum was obtained by infrared spectroscopy ATR method, and then an absorbance ratio (D1780 / D698) was calculated. Then, a calibration curve is drawn by taking the composition ratio (styrene resin ratio in standard sample = mass%) on the vertical axis and the absorbance ratio (D1780 / D698) on the horizontal axis. Based on this calibration curve, the composition ratio of the styrene resin and the methyl methacrylate resin was determined.

Also, as a standard sample of styrene resin and maleic anhydride resin, a 1/1 copolymer of styrene and maleic anhydride (trade name SMA 1000 (P) made by CRAY VALLEY Co., Ltd.) and 3/1 co-polymer of styrene and maleic anhydride A polymer (SMA 3000 (P) CRAY VALLEY) was used.
For each standard sample, an infrared absorption spectrum was obtained by infrared spectroscopy ATR method, and then an absorbance ratio (D1720 / D698) was calculated. Then, a calibration curve is drawn by taking the composition ratio (styrene resin ratio in standard sample = mass%) on the vertical axis and the absorbance ratio (D1720 / D698) on the horizontal axis. Based on this calibration curve, the composition ratio of styrene resin and maleic anhydride resin was determined.

From the calibration curve, the composition ratio of styrene and methyl methacrylate and styrene and maleic anhydride was determined. From the respective compositional proportions, the compositional proportions of the three components of styrene, methyl methacrylate and maleic anhydride in the resin were determined by the following procedure.
Here, the ratio of each standard sample was set as follows.
Methyl methacrylate: Styrene = A: B [1]
Styrene: maleic anhydride = C: D [2]
Since styrene is a common term, the styrene proportion C of [2] was adjusted to the styrene proportion B of [1].
From [2] Styrene: maleic anhydride = C: D
= C x (B / C): D x (B / C)
= B: D x (B / C) [3]
From [3], since the ratio of styrene is equal to [1], the presence ratio of methyl methacrylate, styrene and maleic anhydride is as follows from [1] and [3].
Methyl methacrylate: styrene: maleic anhydride = A: B: D x (B / C) [4]
From the abundance ratio of [4], the ratio of each component was as follows.
Methyl methacrylate = {A / ((A + B + D x (B / C))) x 100
Styrene = {B / ((A + B + D x (B / C))) x 100
Maleic anhydride = {D x (B / C) / ((A + B + D x (B / C))) x 100

(Surface smoothness of fiber reinforced composite)
A 20 × magnified image of the fiber reinforced surface of the fiber reinforced composite was taken using a digital microscope (“VHX-1000” manufactured by KEYENCE, lens: VH-Z 20R). The obtained enlarged photograph was printed on A4 size paper. In the paper surface obtained, an arbitrary area of 25 cm × 20 cm was selected. In the arbitrary area | region, the diagram which drew the line visually by the boundary of the area | region which is in contact with the area | region which is not in contact with the flat plate metal mold was obtained. Using a diagram, the ratio of non-contacting area to the whole area was calculated. This ratio was taken as the surface smoothness. When the surface smoothness ratio is small, the plastic component in the fiber-reinforced plastic forming material is less dropped, and as a result, it is judged that the area in contact with the flat plate mold is large and the beautifulness of the fiber-reinforced surface is high.

Example 1
(Resin particle production process)
Styrene-Methyl methacrylate-maleic anhydride copolymer A (trade name "DENKA REGISFY R-310" manufactured by Denki Kagaku Kogyo Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight Styrene-maleic anhydride-N-phenylmaleimide copolymer B (manufactured by Denki Kagaku Kogyo K.K., trade name "DENKA IP MS-NIP", styrene: 57 parts by weight, density: 1.15 g / cm ³ ) A resin composition containing 5 parts by weight of maleic anhydride, 38 parts by weight of N-phenylmaleimide, a density of 1.18 g / cm ³ and a glass transition temperature of 180 ° C.) is used in a twin screw extruder of 30 mm diameter. It supplied and melt-kneaded at 260 degreeC. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle die (12 nozzles with a diameter of 1.0 mm were arranged in a circle) attached to the front end of a twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. Then, after sufficiently draining the cooled strand resin, it was cut into small particles using a pelletizer to produce resin particles. The obtained resin particles had a particle length L of 1.3 to 1.8 mm and a particle diameter D of 1.0 to 1.2 mm.

(Impregnation process)
100 parts by weight of the above resin particles were sealed in a pressure vessel, and the inside of the pressure vessel was replaced with carbon dioxide gas, and then carbon dioxide gas was pressed in to an impregnation pressure of 0.5 MPa. It was left to stand in a 20 ° C. environment, and after 24 hours of impregnation time, the pressure vessel was slowly depressurized for 5 minutes. In this manner, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the depressurization in the impregnation step, the expandable particles were taken out from the pressure vessel, and then 0.08 parts by weight of calcium carbonate was added and mixed. Thereafter, the above impregnated material was foamed with steam in a high-pressure foaming tank while stirring for 150 seconds at a foaming temperature of 146 ° C. using steam. After foaming, the particles were removed from the high-pressure foaming tank, calcium carbonate was removed with an aqueous solution of hydrogen chloride, and drying was carried out with a flash dryer to obtain foamed particles. The bulk ratio of the expanded particles was 10 times.

(Molding process)
The resulting expanded particles were allowed to stand at room temperature (23 ° C.) for 1 day and then sealed in a pressure vessel. After the inside of the pressure vessel was replaced with carbon dioxide gas, carbon dioxide gas was introduced to an impregnation pressure (gauge pressure) of 0.4 MPa. It was left to stand under an environment of 20 ° C. and pressurized curing was carried out for 8 hours. After taking it out, it is filled in a molding die of 30 mm × 300 mm × 400 mm, heated for 60 seconds with steam of 0.45 MPa, and then cooled until the maximum surface pressure of the foam molded body drops to 0.01 MPa. Thus, a foamed molded product of thickness 30 mm × length 300 mm × width 400 mm was obtained. The multiple of the foamed molded product was 10 times.

(Fiber strengthening process)
A fiber-reinforced plastic former (thickness 0.23 mm, fabric weight: 200 g / g) in which 40% by weight of uncured epoxy resin (glass transition temperature 128 ° C.) is impregnated in a reinforcing fiber base made of twill woven of carbon fibers. There were prepared m ² pieces of “Pyrofill Prepreg TR 3523-395 GMP” manufactured by Mitsubishi Rayon Co., Ltd.).
The two fiber-reinforced plastic formers were superposed such that the crossing angle between the longitudinal directions of the warps of the reinforcing fiber base was 90 °. Next, a portion where two fiber reinforced plastic forming materials overlap one another is cut out into a planar rectangular shape of 300 mm long × 400 mm wide to prepare a laminated fiber reinforced plastic forming material. Another laminated fiber reinforced plastic former was produced in the same manner.
A laminated fiber reinforced plastic forming material was laminated on each of both sides orthogonal to the thickness direction of the foam molded article to prepare a laminate having a thickness of about 31 mm.
Subsequently, the laminate is disposed between flat plate molds, and press molding is performed by clamping a flat plate mold on which a spacer of 30 mm thickness is disposed, thereby thermally bonding the fiber reinforced plastic to the foam molded article. A fiber reinforced composite was made.
In addition, at the time of press molding, the laminate was brought to 135 ° C. and held for 8 minutes to cure the resin contained in the fiber reinforced plastic. By this curing, the fibers of the fiber reinforced plastic were bound and fixed with the cured epoxy resin, and the fiber reinforced plastic was laminated and integrated on both sides of the foam molded body to produce a fiber reinforced composite.
After cooling the fiber reinforced composite to 30 ° C. or less, the flat plate mold was opened to take out a fiber reinforced composite having a thickness of 30 mm.

(Example 2)
In the resin particle production process, 85 parts by weight of styrene-methyl methacrylate-maleic anhydride copolymer A and 15 parts by weight of styrene-maleic anhydride-N-phenylmaleimide copolymer B, and a molding process In the same manner as in Example 1 except that heating was carried out with steam of 0.43 MPa for 60 seconds, foam particles, a foam molded article, and a fiber reinforced composite were obtained.

(Example 3)
In the resin particle production process, 90 parts by weight of styrene-methyl methacrylate-maleic anhydride copolymer A and 10 parts by weight of styrene-maleic anhydride-N-phenylmaleimide copolymer B, and a foaming step In the case of using a steam at a foaming temperature of 143 ° C. for 150 seconds while stirring, using a steam at a high pressure in a foaming tank, and in the forming process, performing heating for 60 seconds with steam of 0.40 MPa. In the same manner as in Example 1, foamed particles, a foamed molded article, and a fiber reinforced composite were obtained.

(Comparative example 1)
In the resin particle production process, not using styrene-maleic anhydride-N-phenyl maleimide copolymer, and in the foaming process, using a steam at a foaming temperature of high pressure while stirring at a foaming temperature of 142 ° C. for 150 seconds Foamed particles, a foam molded article, and a fiber-reinforced composite were obtained in the same manner as in Example 1 except that foaming was performed and heating was performed with steam of 0.38 MPa for 60 seconds in the forming step.

The contents of the base resin of Examples 1 to 3 and Comparative Example 1, the bulk multiple of the foamed particles, the multiple of the foamed molded product, and the surface smoothness of the fiber reinforced composite are shown in Table 1. Further, photographs and corresponding diagrams of the fiber-reinforced surface of the fiber-reinforced composites of Examples 1 to 3 and Comparative Example 1 are shown in FIGS. 1 to 4. In these figures, (a) is a photograph and (b) is a diagram.

A: copolymer A
B: copolymer B
ST: styrene MAM: methyl methacrylate MAH: maleic anhydride NPM: N-phenylmaleimide

It can be seen from Table 1 that the foamed particles of Examples 1 to 3 can give a fiber-reinforced composite with improved surface aesthetics. Further, it can be confirmed from FIGS. 1 to 4 that the fiber-reinforced composites of Examples 1 to 3 have a beautiful surface.

Claims (9)

1. A base resin comprising an aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B, Expanded particles for producing a fiber-reinforced composite, wherein the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B.
2. The expanded particles for producing a fiber-reinforced composite according to claim 1, wherein the base resin has a glass transition temperature Tg of 115 to 160 属 C.
3. The aromatic vinyl is styrene, α-methylstyrene, vinyltoluene, ethylstyrene, i-propylstyrene, t-butylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, divinylbenzene, trivinylbenzene, divinyltoluene, divinylxylene , Bis (vinylphenyl) methane, bis (vinylphenyl) ethane, bis (vinylphenyl) propane, bis (vinylphenyl) butane, divinylnaphthalene, divinylanthracene, divinylbiphenyl, ethylene oxide adduct of bisphenol A, di (meth) acrylate and It is selected from propylene oxide adduct di (meth) acrylate of bisphenol A,
   The (meth) acrylic ester is selected from methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and butyl (meth) acrylate,
   The unsaturated dicarboxylic acid is selected from maleic acid, itaconic acid, citraconic acid, aconitic acid and their anhydrides,
   The fiber-reinforced composite according to claim 1, wherein the unsaturated dicarboximide is selected from maleimide, N-methyl maleimide, N-ethyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide and N-naphthyl maleimide. Foam particles.
4. When the copolymer A has a total of 100 parts by weight of units derived from three of an aromatic vinyl, a (meth) acrylate and an unsaturated dicarboxylic acid, 30 to 80 parts of a unit derived from an aromatic vinyl Part, containing 8 to 35 parts by weight of a unit derived from (meth) acrylic acid ester and 10 to 50 parts by weight of a unit derived from unsaturated dicarboxylic acid,
   When the copolymer B has a total of 100 parts by weight of units derived from aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboximide, 20 to 80 parts by weight of units derived from aromatic vinyl An expanded particle for producing a fiber-reinforced composite according to claim 1, comprising 2 to 30 parts by weight of a unit derived from unsaturated dicarboxylic acid and 20 to 80 parts by weight of a unit derived from unsaturated dicarboxylic acid imide.
5. A base resin comprising an aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B, A foam-molded article for producing a fiber-reinforced composite, wherein the copolymer B is contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B.
6. A base resin comprising an aromatic vinyl- (meth) acrylate-unsaturated dicarboxylic acid copolymer A and an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboximide copolymer B, The copolymer B has a foam-molded article contained in an amount of 1 to 50% by weight based on the total of the copolymers A and B, and a fiber reinforced plastic layer laminated and integrated on the surface of the foam molded article. Fiber reinforced composite.
7. The fiber reinforced composite according to claim 6, wherein the fiber reinforced composite is used for a wind turbine blade, a robot arm or an automotive part.
8. The fiber reinforced composite according to claim 6, wherein the fiber reinforced composite has a surface smoothness of 10% or less.
9. An automobile part comprising the fiber reinforced composite according to claim 6.

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