WO2019188052A1

WO2019188052A1 - Foam particles, foam molded article, fiber-reinforced composite article and automobile parts

Info

Publication number: WO2019188052A1
Application number: PCT/JP2019/008696
Authority: WO
Inventors: 佑輔 ▲桑▼▲原▼
Original assignee: 積水化成品工業株式会社
Priority date: 2018-03-30
Filing date: 2019-03-05
Publication date: 2019-10-03

Abstract

Provided are foam particles constituted of a base resin including a copolymer of an aromatic vinyl, a (meth)acrylic acid ester, and an unsaturated dicarboxylic acid. In a 30-times magnification cross-sectional image of a 11.9 mm² area of one of the foam particles, the foam particle has small bubbles having a diameter of 50 μm or greater but less than 300 μm and large bubbles having a diameter of 300 μm-2 mm.

Description

Foamed particles, foamed molded products, fiber reinforced composites, and automotive parts

The present invention relates to expanded particles, expanded molded articles, fiber reinforced composites, and automotive parts. More specifically, the present invention relates to a foamed particle that can provide a foamed molded article having improved mechanical properties (for example, heat insulation, maximum point stress by bending test), and a foamed molded article obtained from the foamed particle, fiber reinforced. The present invention relates to composites and automotive parts.

In recent years, vehicles such as aircraft, automobiles, and ships have been required to improve fuel efficiency in order to reduce the burden on the global environment, and the metal materials that make up these vehicles have been changed to resin materials to achieve significant weight savings. The flow is getting stronger. Examples of these resin materials include fiber reinforced plastics, and it has been studied to further reduce weight and increase rigidity by using a lightweight core material in part. Polystyrene foam having high compressive strength has been studied as a material used as a lightweight core material.
However, since the polystyrene-based resin has a low glass transition temperature, mechanical properties such as heat resistance are not sufficient. Therefore, it has been desired to provide a foamed molded article having improved mechanical properties and foamed particles capable of producing the foamed molded article.
Therefore, the applicant of the present application repeated the test under the idea that mechanical properties would be improved if another type of resin was used instead of the polystyrene resin. As a result, when using a copolymer of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid as a base resin for the foamed particles, the mechanical properties of the foamed molded product can be improved to some extent, It has been found that mechanical properties can be greatly improved by controlling the bubble diameter of the expanded particles while using this base resin (Japanese Patent Laid-Open No. 2017-186503: Patent Document 1).

JP 2017-186503 A

However, the foamed molded article of Patent Document 1 has room for improvement in terms of mechanical properties (for example, heat insulation, maximum point stress by bending test), and mechanical properties that are further superior to the foamed molded article of Patent Document 1. It is desired to provide a foamed molded article having a foam and foamed particles capable of producing the foamed molded article.
Then, this invention makes it a subject to provide the foaming particle | grains which can manufacture the foaming molding which shows the outstanding mechanical property (for example, heat insulation, the maximum point stress by a bending test), and the foaming molding.

The inventor of the present invention further examined the technique of Patent Document 1, and by increasing the bubble diameter difference between small bubbles and large bubbles, mechanical properties (for example, heat insulation, maximum point stress by bending test). The present invention has been completed by surprisingly finding that it is possible to significantly improve the above.

Thus, according to the present invention, there are expanded particles composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and the expanded particles are 30 times larger. in the cross section photograph of an area of 11.9 mm ^2, the foamed particles are provided and a large bubble of the small bubble and less bubble diameter 300 [mu] m or more and 2mm of bubble size of less than 50μm and not more than 300 [mu] m.
Further, according to the present invention, there is provided a foam molded article composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, wherein the foam molded article is In a cross-sectional photograph composed of a plurality of the foamed particles, the foamed particles having an area of 11.9 mm ² taken 30 times, a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a bubble of 300 μm or more and 2 mm or less There is provided a foamed molded article having large diameter bubbles.
Furthermore, according to the present invention, there is provided a fiber reinforced composite comprising the above foam molded article and a fiber reinforced plastic layer laminated and integrated on the surface of the foam molded article.
Moreover, according to this invention, the components for motor vehicles comprised from said foaming molding or a fiber reinforced composite are provided.

ADVANTAGE OF THE INVENTION According to this invention, the foaming molding which can manufacture the foaming molding which shows the outstanding mechanical property (for example, heat insulation, the maximum point stress by a bending test), and the foaming molding can be provided.
Further, in any of the following cases, a foamed molded article exhibiting more excellent mechanical properties (for example, heat insulation, maximum point stress by a bending test) and foamed particles capable of producing the foamed molded article can be provided.
(1) The expanded particles have only one large bubble in one of them.
(2) Aromatic vinyl is a styrene monomer, (meth) acrylic acid ester is (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), and unsaturated dicarboxylic acid is 2 to 6 carbon atoms An aliphatic unsaturated dicarboxylic acid, and the copolymer is aromatic when the total of units derived from three of vinyl aromatic, (meth) acrylic acid ester and unsaturated dicarboxylic acid is 100 parts by weight. 30 to 80 parts by weight of units derived from 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.
(3) The difference between the average bubble diameter of the small bubbles and the average bubble diameter of the large bubbles is 1450 μm or more, and the foamed molded product is 0.0350 W / m · K or less in the foamed molded body composed of the fused body. Gives the thermal conductivity of.
(4) Expanded particles composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid, and the expanded particles are 11.9 mm ² at 30 times. A cross-sectional photograph of the area of the above, comprising a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a large bubble having a bubble diameter of 300 μm or more and 2 mm or less, the average bubble diameter of the small bubbles and the average bubble diameter of the large bubbles The foamed particles give a maximum point stress by a bending test of 1.0 MPa or more to the foamed molded body composed of the fused product.
(5) The aromatic vinyl is styrene, α-methylstyrene, vinyltoluene, ethylstyrene, i-propylstyrene, t-butylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, divinylbenzene, trivinylbenzene, divinyltoluene, Divinyl xylene, bis (vinylphenyl) methane, bis (vinylphenyl) ethane, bis (vinylphenyl) propane, bis (vinylphenyl) butane, divinylnaphthalene, divinylanthracene, divinylbiphenyl, bisphenol A ethylene oxide adduct di (meth) Selected from acrylate and propylene oxide adduct di (meth) acrylate of bisphenol A;
(Meth) acrylic acid 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 anhydrides thereof.
(6) Copolymer A of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, copolymer B of aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboxylic imide The difference between the glass transition temperature A of the copolymer A and the glass transition temperature B of the copolymer B is 10 to 50 ° C., and the expanded particles are 30 In a cross-sectional photograph obtained by photographing an area of 11.9 mm ^{2 at} a magnification, a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a large bubble having a bubble diameter of 300 μm or more and 2 mm or less are provided.
(7) In copolymer A, aromatic vinyl is a styrene monomer, (meth) acrylic ester is (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), and unsaturated dicarboxylic acid is Each of which is selected from aliphatic unsaturated dicarboxylic acids having 2 to 6 carbon atoms, and copolymer A has a total of 100 units derived from three of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid. 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 Including
In the copolymer B, the aromatic vinyl is selected from a styrene monomer, the unsaturated dicarboxylic acid is an aliphatic unsaturated dicarboxylic acid having 2 to 6 carbon atoms, and the unsaturated dicarboxylic imide is a maleimide monomer. When the total of the units derived from the copolymer B in three units of the aromatic vinyl, the unsaturated dicarboxylic acid, and the unsaturated dicarboxylic imide is 100 parts by weight, the unit derived from the aromatic vinyl is 20 to 80 parts by weight. 2-30 parts by weight of units derived from unsaturated dicarboxylic acid and 20-80 parts by weight of units derived from unsaturated dicarboxylic imide.
(8) Aromatic vinyl is styrene, α-methylstyrene, vinyltoluene, ethylstyrene, i-propylstyrene, t-butylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, divinylbenzene, trivinylbenzene, divinyltoluene, Divinyl xylene, bis (vinylphenyl) methane, bis (vinylphenyl) ethane, bis (vinylphenyl) propane, bis (vinylphenyl) butane, divinylnaphthalene, divinylanthracene, divinylbiphenyl, bisphenol A ethylene oxide adduct di (meth) Selected from acrylate and propylene oxide adduct di (meth) acrylate of bisphenol A;
(Meth) acrylic acid 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 anhydrides thereof;
The unsaturated dicarboxylic imide is selected from maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N-naphthylmaleimide;
Copolymers A and B are contained in the base resin in a weight ratio of 70:30 to 95: 5.

2 is a cross-sectional photograph of expanded particles and expanded molded articles of Examples 1a to 3a. It is a cross-sectional photograph of the expanded particle of Comparative Example 1a and 2a, and a foaming molding. It is a cross-sectional photograph of the expanded particle of Example 4a and 5a and a foaming molding. 2 is a cross-sectional photograph of expanded particles and expanded molded articles of Examples 6a to 8a. It is a cross-sectional photograph of the expanded particle of Example 1b and 2b, and a foaming molding. It is a cross-sectional photograph of the expanded particle of Example 3b and a foaming molding. It is a cross-sectional photograph of the expanded particle of Example 4b and a foaming molding. 2 is a cross-sectional photograph of expanded particles and expanded molded articles of Reference Examples 1b to 3b. It is a cross-sectional photograph of the expanded particle of Example 1c and 2c and a foaming molding. It is a cross-sectional photograph of the expanded particle of Example 3c and a foaming molding. It is a cross-sectional photograph of the expanded particle of Example 4c and 5c, and a foaming molding. 3 is a cross-sectional photograph of expanded particles and expanded molded articles of Reference Examples 1c to 3c. 2 is a cross-sectional photograph of expanded particles and expanded molded articles of Examples 1d to 3d. It is a cross-sectional photograph of the expanded particles and expanded molded article of Reference Example 3d.

(1) Foamed Particles (1-1) Base Resin Foamed particles are composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid. The proportion of the copolymer in the base resin is preferably 70% by weight or more, more preferably 85% by weight or more, and may be 100% by weight. The copolymer preferably has a glass transition temperature Tg of 115 to 160 ° C. When Tg is lower than 115 ° C., lamination and integration of the skin material on the surface of the foamed molded product produced using the foamed particles may be insufficient, and mechanical properties may be lowered. When the temperature is higher than 160 ° C., the foamability of the foamed particles is lowered, and the heat fusion integration between the foamed particles is insufficient, and the mechanical properties of the foamed molded product may be lowered. Tg can take 115 ° C, 120 ° C, 130 ° C, 140 ° C, 150 ° C and 160 ° C. A more preferable Tg is 120 to 150 ° C.

(A) Aromatic vinyl Aromatic vinyl is an aromatic compound having a substituent composed of a vinyl group. The number of vinyl groups and the number of carbon atoms of the aromatic compound are not particularly limited. Specific aromatic vinyls include styrene monofunctional monomers such as 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, Examples thereof include bisphenol A ethylene oxide adduct di (meth) acrylate and bisphenol A propylene oxide adduct di (meth) acrylate. Aromatic vinyl may be used independently or 2 or more types may be used together. Of these, styrene is preferred from the viewpoint of availability.

(B) (Meth) acrylic acid ester The (meth) acrylic acid ester is not particularly limited, and examples thereof include (meth) acrylic acid alkyl esters. The alkyl group in the (meth) acrylic acid alkyl ester may have 1 to 5 carbon atoms. Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. (Meth) acrylic acid ester may be used independently, or 2 or more types may be used together. From the viewpoint of improving the mechanical properties of the foam molded article, methyl (meth) acrylate is preferred, and methyl methacrylate is more preferred.
(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 examples of the unsaturated dicarboxylic acid include maleic acid, itaconic acid, citraconic acid, aconitic acid, and anhydrides thereof. Unsaturated dicarboxylic acid may be used independently or 2 or more types may be used together.

(D) Ratio of units derived from aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid The total number of units derived from aromatic vinyl, (meth) acrylic acid 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 contain.
When the proportion of units derived from aromatic vinyl is less than 30 parts by weight, the foamability of the foamed particles is reduced during foam molding, and the heat fusion integration between the foamed particles becomes insufficient, and Mechanical properties may deteriorate. When this ratio is larger than 80 parts by weight, the heat resistance of the foamed molded product may be lowered. This ratio can take 30 parts, 40 parts, 45 parts, 50 parts, 60 parts, 70 parts, 75 parts and 80 parts by weight. This ratio is more preferably 40 to 75 parts by weight, and still more preferably 45 to 70 parts by weight.
When the proportion of units derived from (meth) acrylic acid ester is less than 8 parts by weight, the mechanical properties of the foamed molded product may be lowered. When this ratio is larger than 35 parts by weight, the foamability of the foamed particles may be reduced during foam molding, and the heat fusion integration between the foamed particles may be insufficient and the mechanical properties of the foamed molded product may be degraded. is there. This ratio can take 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 33 parts and 35 parts by weight. This ratio is more preferably 10 to 33 parts by weight, and further preferably 15 to 30 parts by weight.
When the ratio which the unit derived from unsaturated dicarboxylic acid accounts is less than 10 weight part, the heat resistance of a foaming molding may fall. When this ratio is larger than 50 parts by weight, the foamability of the foamed particles may be reduced during foam molding, and the heat-fusion integration between the foamed particles may be insufficient, and the mechanical properties of the foamed molded product may be degraded. is there. This ratio can take 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. This ratio is more preferably 15 to 40 parts by weight, still more preferably 20 to 35 parts by weight.
In addition, the usage-amount of a monomer and content of the unit derived from the monomer are substantially in agreement.
The ratio of each component, that is, the ratio of units derived from aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and further derived from other monomers and other resins described below is ¹ It can be defined by the peak height of H-NMR or the area ratio of FT-IR. A specific measurement method will be described in Examples.

(E) Other monomer The base resin may be a further copolymer with components derived from other monomers as long as the properties of the present invention are not impaired in addition to the above three monomers. 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 the base resin is preferably 30% by weight or less, and may be 0% by weight.
(F) Other resin Other resin may be mixed with the base resin. As other resins, rubber-modified resistance such as polyolefin resins such as polyethylene and polypropylene, polybutadiene, styrene-butadiene copolymers, and diene rubber polymers such as ethylene-propylene-nonconjugated diene three-dimensional copolymers are added. Impact polystyrene resin, polycarbonate resin, polyester resin, polyamide resin, polyphenylene ether, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polymethyl methacrylate, styrene- (meth) acrylic acid copolymer, Examples thereof include styrene- (meth) acrylic acid ester copolymers and aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboxylic imide copolymers.
Of the other resins, the expanded particles preferably contain polymethyl methacrylate. By containing poly (methyl methacrylate), the heat-fusibility of the foamed particles is improved, and the foamed particles are more strongly heat-fused and integrated with each other. Obtainable. The content of polymethyl 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 foamed particles preferably contain an acrylic resin as a processing aid. By containing a processing aid, the foam tension of the foamed particles is suppressed by making the melt tension (viscoelasticity) at the time of foaming of the resin constituting the foamed particles suitable for foaming. Thus, it is possible to produce a foamed molded article having improved mechanical properties by further strengthening heat fusion between the foamed particles. The content of the processing aid in the expanded particles is preferably 0.5 to 5 parts by weight, 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 composed of two or more of these, and an acrylic monomer. Examples thereof include a copolymer of an acrylic monomer and a vinyl monomer copolymerizable therewith. Examples of the acrylic monomer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like. Examples of vinyl monomers copolymerizable with acrylic monomers include α-methylstyrene and acrylonitrile. 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) during foam molding of the resin constituting the foamed particles to that suitable for foaming. The foamability of the particles may not be improved.

(G) Aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboxylic imide copolymer The above (f) other resin includes an aromatic vinyl-unsaturated dicarboxylic acid-unsaturated dicarboxylic imide copolymer (copolymer). Polymer B) is preferred from the viewpoint of improving the heat resistance and / or elastic modulus of the foamed molded product.
Specifically, the expanded particles include a copolymer of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid (also referred to as copolymer A), aromatic vinyl, and unsaturated dicarboxylic acid. And a base resin containing copolymer B with unsaturated dicarboxylic imide. When the base resin contains the copolymer B, the heat resistance and / or elastic modulus of the obtained foamed molded product can be improved as compared with the case where the base resin is made of only the copolymer A. The ratio of the total of copolymers A and B in the base resin is preferably 70% by weight or more, more preferably 85% by weight or more, and may be 100% by weight. Copolymers A and B are preferably contained in the base resin in a weight ratio of 70:30 to 95: 5. The weight ratio of copolymers A and B can be 70:30, 75:25, 80:20, 85:15, 90:10 and 95: 5. A more preferred weight ratio is 80:20 to 90:10.
The copolymer A preferably has a glass transition temperature Tg of 115 to 160 ° C. When Tg is lower than 115 ° C., lamination and integration of the skin material on the surface of the foamed molded product produced using the foamed particles may be insufficient, and mechanical properties may be lowered. When the temperature is higher than 160 ° C., the foamability of the foamed particles is lowered, and the heat fusion integration between the foamed particles is insufficient, and the mechanical properties of the foamed molded product may be lowered. Tg can take 115 ° C, 120 ° C, 130 ° C, 140 ° C, 150 ° C and 160 ° C. A more preferable Tg is 120 to 150 ° C.
The copolymer B preferably has a glass transition temperature Tg of 160 to 200 ° C. When Tg is lower than 160 ° C., the laminate integration of the skin material on the surface of the foam molded body produced using the foamed particles may be insufficient, and the mechanical properties may be lowered. When the temperature is higher than 200 ° C., the foamability of the foamed particles is lowered, and the heat fusion integration between the foamed particles is insufficient, and the mechanical properties of the foamed molded product may be lowered. Tg can take 160 ° C, 170 ° C, 180 ° C, 190 ° C and 200 ° C. A more preferable Tg is 170 to 190 ° C.
The difference between the glass transition temperature A of the copolymer A and the glass transition temperature B of the copolymer B is 10 to 50 ° C. When the difference is less than 10 ° C., sufficient heat resistance improvement effect cannot be obtained, and the lamination and integration of the skin material on the surface of the foam molded body produced using the foamed particles becomes insufficient, resulting in mechanical Physical properties may deteriorate. When the temperature is higher than 50 ° C., the difference in melt viscosity becomes large and kneading may be insufficient. The difference can be 10 ° C, 20 ° C, 30 ° C, 35 ° C, 45 ° C, 47 ° C and 50 ° C. The difference is preferably 20 to 47 ° C, more preferably 30 to 45 ° C.

Although it does not specifically limit as aromatic vinyl, The compound illustrated to said (a) is mentioned. Aromatic vinyl may be used independently or 2 or more types may be used together. Of these, styrene is preferred from the viewpoint of availability.
Although it does not specifically limit as unsaturated dicarboxylic acid, The compound illustrated in said (c) is mentioned. Unsaturated dicarboxylic acid may be used independently or 2 or more types may be used together. From the viewpoint of improving the mechanical properties of the foam molded article, maleic anhydride is preferable.
The unsaturated dicarboxylic acid imide is not particularly limited, and examples thereof include maleimide monomers such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N-naphthylmaleimide. . An unsaturated dicarboxylic imide derivative may be used independently or 2 or more types may be used together. From the viewpoint of improving the heat resistance of the foam molded article, N-phenylmaleimide is preferred.
The proportion of units derived from aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboxylic imide is 20 to 80 parts by weight of units derived from aromatic vinyl, assuming that the total of the units derived from 3 is 100 parts by weight. It is preferable that 2 to 30 parts by weight of units derived from unsaturated dicarboxylic acid and 20 to 80 parts by weight of units derived from unsaturated dicarboxylic imide are included.
When the proportion of units derived from aromatic vinyl is less than 20 parts by weight, the foamability of the foamed particles is reduced during foam molding, and the thermal fusion integration between the foamed particles becomes insufficient, and Mechanical properties may deteriorate. When this ratio is larger than 80 parts by weight, the heat resistance of the foamed molded product may be lowered. This ratio can take 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 75 parts by weight and 80 parts by weight. This ratio is more preferably 30 to 75 parts by weight, and still more preferably 50 to 70 parts by weight.
The proportion of units derived from unsaturated dicarboxylic acids can be 2 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight and 30 parts by weight. The proportion of units derived from unsaturated dicarboxylic imides can be 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 75 parts and 80 parts by weight.

When the base resin includes the copolymer A and the copolymer B, it is preferable that polymethyl methacrylate is contained as the other resin. By containing poly (methyl methacrylate), the heat-fusibility of the foamed particles is improved, and the foamed particles are more strongly heat-fused and integrated with each other. Obtainable. The content of polymethyl methacrylate in the expanded particles is preferably 10 to 500 parts by weight, more preferably 20 to 450 parts by weight, and more preferably 30 to 400 parts by weight with respect to 100 parts by weight of the total of the copolymers A and B. Particularly preferred.
When the base resin contains the copolymer A and the copolymer B, it is preferable that the foamed particles contain an acrylic resin as the processing aid. By containing a processing aid, the foam tension of the foamed particles is suppressed by making the melt tension (viscoelasticity) at the time of foaming of the resin constituting the foamed particles suitable for foaming. Thus, it is possible to produce a foamed molded article having improved mechanical properties by further strengthening heat fusion between the foamed particles. The content of the processing aid in the expanded particles is preferably 0.5 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total of the copolymers A and B.
(H) Additive The base resin may contain an additive in addition to the resin, if necessary. Additives include plasticizers, flame retardants, flame retardant aids, antistatic agents, spreading agents, foam control agents, fillers, colorants, weathering agents, anti-aging agents, lubricants, antifogging agents, fragrances, etc. Can be mentioned.

(1-2) Configuration Foamed particles have a bubble size of 50 μm or more and less than 300 μm and a bubble size of 300 μm or more and 2 mm or less in a cross-sectional photograph of the entire expanded particle taken at an area of 11.9 mm ² at 30 times magnification. With large bubbles.
Further, the number of large bubbles per one expanded particle is not particularly limited and may be plural. However, if the number is too large, the bubble rate is increased, and the mechanical properties of the foamed molded product are lowered. For this reason, it is preferable that the expanded particle has only one large bubble in one of them, although it depends on the bubble diameter of the large bubble.
Moreover, it is preferable that there is a difference of 300 μm or more between the average bubble diameter of small bubbles and the average bubble diameter of large bubbles. Due to this difference, it is possible to provide foamed particles that give a foamed molded article having improved mechanical properties. The difference may be 300-600 μm. The difference can be 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm and 600 μm. Here, the average bubble diameter of small bubbles may be in the range of 100 to 250 μm, and the average bubble diameter of large bubbles may be in the range of 350 to 900 μm. The average bubble diameter of small bubbles can be 100 μm, 150 μm, 200 μm and 250 μm, and the average bubble diameter of large bubbles can be 350 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm and 900 μm.
Further, there may be a difference of 1000 μm or more and less than 1500 μm between the average bubble diameter of small bubbles and the average bubble diameter of large bubbles. Due to this difference, it is possible to provide foamed particles that give a foamed molded article having improved mechanical properties. The difference can be 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm and 1499 μm. Here, the average bubble diameter of the small bubbles may be in the range of 30 to 100 μm, and the average bubble diameter of the large bubbles may be in the range of 1200 to 1600 μm. The average bubble diameter of small bubbles can be 30 μm, 50 μm, 70 μm and 100 μm, and the average bubble diameter of large bubbles can be 1200 μm, 1300 μm, 1400 μm, 1500 μm and 1600 μm.
Since the foamed particles give a maximum point stress by a bending test of 1.0 MPa or more to the foamed molded body composed of the fused body, a foamed molded body resistant to bending can be provided. The range of the maximum point stress can be realized by using foamed particles that use a specific resin as a base resin and have bubbles in a specific bubble diameter range. The maximum point stress is preferably 1.0 MPa or more, and more preferably 1.5 MPa or more.

The outer shape of the expanded particles is not particularly limited as long as the expanded molded body can be produced, and examples thereof include a spherical shape, a substantially spherical shape, and a cylindrical shape. The expanded particles preferably have an outer shape represented by an average aspect ratio of 0.7 or more (the upper limit is 1 true sphere).
The expanded particles preferably have a bulk multiple of 30 to 2 times. When the bulk factor is larger than 30 times, the open cell ratio of the foamed particles increases, and the foamability of the foamed particles may decrease during foam molding. If it is less than 2 times, the foamed particles may have uneven bubbles, and the foamability of the foamed particles during foam molding may be insufficient. The bulk multiple is more preferably 25 to 3 times, and particularly preferably 20 to 5 times.

(1-3) Manufacturing Method As a manufacturing method of the expanded particles, there is a method in which the expandable particles are obtained by impregnating the resin particles with a foaming agent in a gas phase, and the expandable particles are expanded.
The resin particles can be obtained using a known production method and production equipment. Here, the adjustment of the number of voids described below can be performed, for example, by adjusting the amount of chemical foaming agent added to the resin.
For example, resin particles can be produced by melt-kneading the raw material resin using an extruder and then granulating by extrusion, underwater cut (underwater cut), strand cut, or the like. The temperature, time, pressure, etc. at the time of melt-kneading can be appropriately set according to the raw materials used and the production equipment.
The melt kneading temperature in the extruder during melt kneading is preferably 220 to 280 ° C., more preferably 240 to 270 ° C., which is a temperature at which the raw material resin is sufficiently softened. The melt-kneading temperature means the temperature of the melt-kneaded material inside the extruder as measured at the center temperature of the melt-kneaded material flow path near the extruder head with a thermocouple thermometer.
The large bubbles, which are one of the characteristics of the expanded particles of the present invention, are considered to be derived from voids formed in the central region of the resin particles by rapid cooling from the surroundings during the production of the resin particles. Therefore, in the production of foamed particles, an underwater cut that is easily controlled for rapid cooling is particularly preferable.
In addition, it is preferable that a bubble regulator is supplied to an extruder. Examples of the air conditioner 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 air bubble adjusting agent is less than 0.01 parts by weight, the foamed bubbles may be coarse and the appearance of the obtained foamed molded product may be deteriorated. When the amount is more than 5 parts by weight, the closed cell ratio of the foamed particles may decrease due to bubble breakage. 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 expandable particles, a method in which a foaming agent is impregnated in a gas phase with a foaming agent in a hermetically sealed container can be mentioned. Examples of the blowing agent include propane, normal butane, isobutane, normal pentane, isopentane, hexane and other saturated aliphatic hydrocarbons, ethers such as dimethyl ether, methyl chloride, 1,1,1,2-tetrafluoroethane, 1, Examples thereof include chlorofluorocarbons such as 1-difluoroethane and monochlorodifluoromethane, and inorganic gases such as carbon dioxide and nitrogen. Among them, dimethyl ether, propane, normal butane, isobutane, and carbon dioxide are preferable, propane, normal butane, isobutane, and carbon dioxide are more preferable, and normal butane, isobutane, and carbon dioxide are particularly preferable. In addition, a foaming agent may be used independently or 2 or more types may be used together.
If the amount of the foaming agent charged into the container is too small, the foamed particles may not be foamed to a desired expansion ratio. If the amount of the foaming agent is too large, the foaming agent acts as a plasticizer, so that the viscoelasticity of the base resin is excessively lowered, the foamability is lowered, and good foamed particles may not be obtained. Accordingly, the amount of the blowing 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 manufacturing method of expanded particle, the method of heating with a heating medium like water vapor | steam in the container which can be sealed is mentioned. Examples of heating conditions include a gauge pressure of 0.3 to 0.5 MPa, a temperature of 120 to 159 ° C., and 10 to 180 seconds.
The particle diameter of the expanded particles can be changed by changing the diameter of a multi-nozzle mold attached to the front end of the extruder.

(2) Foam molded body (2-1) Base resin The base resin constituting the foam molded body is the same as the base resin of the foamed particles.
(2-2) Physical properties The foamed molded article is a cross-sectional photograph obtained by photographing an area of 11.9 mm ^{2 at} a magnification of 30 times. And.
Further, the foam molded body is composed of a plurality of foam particles. Each expanded particle is provided with a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a large bubble having a bubble diameter of 300 μm or more and 2 mm or less in a cross-sectional photograph obtained by photographing an area of 11.9 mm ² at 30 times. .
Further, the number of large bubbles per one expanded particle is not particularly limited and may be plural. However, if the number is too large, the bubble rate is increased, and the mechanical properties of the foamed molded product are lowered. For this reason, it is preferable that the expanded particle has only one large bubble in one of them, although it depends on the bubble diameter of the large bubble.
Moreover, it is preferable that there is a difference of 300 μm or more between the average bubble diameter of small bubbles and the average bubble diameter of large bubbles. Due to this difference, it is possible to provide foamed particles that give a foamed molded article having improved mechanical properties. The difference may be 300-600 μm. The difference can be 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm and 600 μm. Here, the average bubble diameter of small bubbles may be in the range of 100 to 250 μm, and the average bubble diameter of large bubbles may be in the range of 350 to 900 μm. The average bubble diameter of small bubbles can be 100 μm, 150 μm, 200 μm and 250 μm, and the average bubble diameter of large bubbles can be 350 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm and 900 μm.

The outer shape of the fused expanded particles is not particularly limited as long as the expanded molded body can be maintained.
The foamed molded article preferably has a multiple of 30 to 2 times. When the multiple is larger than 30 times, the mechanical properties may be insufficient. If it is less than 2 times, the advantage of foaming may be reduced due to increased weight. The multiple is more preferably 27 to 3 times, further preferably 25 to 3 times, particularly preferably 25 to 5 times, and particularly preferably 20 to 5 times.
Therefore, the foamed molded product may have a density of 0.046 to 0.23 g / cm ³ (46 to 230 kg / m ³ ) or 0.058 to 0.23 g / cm ³ (58 to 230 kg / m ³ ). preferable.

The bending maximum point stress per unit density in the foam molded article is preferably 0.012 MPa / (kg / m ³ ) or more. If the bending maximum point stress is too small, the foamed molded product may be easily broken. As for the bending maximum point stress per unit density in a foaming molding, 0.015 Mpa / (kg / m < ³ >) or more is more preferable.
The flexural modulus per unit density in the foamed molded product is preferably 0.4 MPa / (kg / m ³ ) or more. If the flexural modulus is too small, the foamed molded product may be deformed by pressure applied when a skin material such as fiber reinforced plastic is laminated and integrated on the surface of the foamed molded product.
5% compressive stress per unit density in the foam molded article is preferably from 0.007MPa / (kg / ^{m 3)} or ^{more, 0.008MPa / (kg / m 3} ) or more preferably, 0.009 MPa / (kg / m ³ ) or more is more preferable. If the 5% compressive stress is too small, the foam molded body may be deformed by the pressure applied when a skin material such as fiber reinforced plastic is laminated and integrated on the surface of the foam molded body.
The compression elastic modulus per unit density in the foam molded article is preferably 0.3 MPa / (kg / m ³ ) or more. If the compression elastic modulus is too small, the foam molded body may be deformed by the pressure applied when a skin material such as fiber reinforced plastic is laminated and integrated on the surface of the foam molded body.
Further, there may be a difference of 1450 μm or more between the average bubble diameter of small bubbles and the average bubble diameter of large bubbles. Due to this difference, a foamed molded product with improved heat insulation can be provided. The difference may be 1450-1800 μm. The difference can take 1450 μm, 1500 μm, 1600 μm, 1700 μm and 1800 μm. Here, the average bubble diameter of small bubbles may be in the range of 130 to 180 μm, and the average bubble diameter of large bubbles may be in the range of 1580 to 1980 μm. The average bubble diameter of small bubbles can be 130 μm, 140 μm, 150 μm, 160 μm, 170 μm and 180 μm, and the average bubble diameter of large bubbles can be 1580 μm, 1600 μm, 1700 μm, 1800 μm, 1900 μm and 1980 μm.
Since the expanded particles give a thermal conductivity of 0.0350 W / m · K or less to the expanded molded body composed of the fusion-bonded body, it is possible to provide a expanded molded body for applications requiring high heat insulation. This heat insulating range can be realized by using foamed particles that use a specific resin as a base resin and have bubbles in a specific cell diameter range. The thermal conductivity is preferably 0.0345 W / m · K or less.
Further, there may be a difference of 1000 μm or more and less than 1500 μm between the average bubble diameter of small bubbles and the average bubble diameter of large bubbles. Due to this difference, it is possible to provide foamed particles that give a foamed molded product that is resistant to bending. The difference can be 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm and 1499 μm. Here, the average bubble diameter of small bubbles may be in the range of 30 to 100 μm, and the average bubble diameter of large bubbles may be in the range of 1200 to 1800 μm. The average bubble diameter of small bubbles can be 30 μm, 50 μm, 70 μm and 100 μm, and the average bubble diameter of large bubbles can be 1200 μm, 1300 μm, 1400 μm, 1500 μm and 1600 μm.
Since the foamed particles give a maximum point stress by a bending test of 1.0 MPa or more to the foamed molded body composed of the fused body, a foamed molded body resistant to bending can be provided. The range of the maximum point stress can be realized by using foamed particles that use a specific resin as a base resin and have bubbles in a specific bubble diameter range. The maximum point stress is preferably 1.0 MPa or more, and more preferably 1.5 MPa or more.

(2-3) Manufacturing Method As a manufacturing method of a foamed molded article, the above-mentioned foamed particles are filled into a cavity of a mold, a heating medium is supplied into the cavity, the foamed particles are heated and re-foamed, There is a method of obtaining a foamed molded article by thermally fusing the foamed foamed particles together with these foaming pressures. Examples of the heating medium include water vapor, hot air, hot water, and the like, and water vapor is preferable.

(2-4) Applications The foamed molded article is excellent in light weight, heat resistance, heat insulation, and mechanical properties, and particularly excellent in load resistance in a high temperature environment. Therefore, for example, it can be suitably used for parts of transportation equipment such as automobiles, airplanes, railway vehicles, and ships. Examples of automobile parts include parts used in the vicinity of the engine and exterior materials.
According to the present invention, there is provided an automotive part composed of the foamed molded article of the present invention. Examples of the automotive part include a floor panel, a roof, a bonnet, a fender, an under cover, a wheel, a steering wheel, and a container. (Housing), hood panel, suspension arm, bumper, sun visor, trunk lid, luggage box, seat, door, cowl and other parts.

A skin material may be laminated and integrated on the surface of the foamed molded product to be used as a reinforced composite. When the foamed molded body is a foamed sheet, it is not necessary to be laminated and integrated on both surfaces of the foamed molded body, and the skin material only needs to be laminated and integrated on at least one surface of both surfaces of the foamed molded body. The lamination of the skin material may be determined according to the use of the reinforced composite. Among these, in consideration of the surface hardness and mechanical strength of the reinforced composite, it is preferable that the skin material is laminated and integrated on each of both surfaces in the thickness direction of the foamed molded product.
The skin material is not particularly limited, and examples thereof include fiber reinforced plastics, metal sheets, and synthetic resin films. Of these, fiber reinforced plastic is preferred. A reinforced composite using a fiber reinforced plastic as a skin material is referred to as a fiber reinforced composite.
The reinforcing fibers constituting the fiber reinforced plastic include glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, Tyranno fibers, basalt fibers, ceramic fibers and other inorganic fibers; stainless steel fibers, steel fibers and other metal fibers; aramid Organic fibers such as fibers, polyethylene fibers, polyparaphenylene benzoxazole (PBO) fibers; and boron fibers. Reinforcing fibers may be used alone or in combination of two or more. Among these, 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 fiber is preferably used as a reinforcing fiber substrate processed into a desired shape. Examples of the reinforcing fiber base material include woven fabrics, knitted fabrics, non-woven fabrics, and face materials obtained by binding (stitching) fiber bundles (strands) obtained by aligning reinforcing fibers in one direction with yarns. . Examples of the weaving method include plain weave, twill weave and satin weave. Examples of the yarn include a synthetic resin yarn such as a polyamide resin yarn and a polyester resin yarn, and a stitch yarn such as a glass fiber yarn.
The reinforcing fiber substrate may be used without laminating only one reinforcing fiber substrate, or a plurality of reinforcing fiber substrates may be laminated and used as a laminated reinforcing fiber substrate. As a laminated reinforcing fiber base material in which a plurality of reinforcing fiber base materials are laminated, (1) a plurality of reinforcing fiber base materials of only one kind are prepared, and a laminated reinforcing fiber base material in which these reinforcing fiber base materials are laminated, 2) A plurality of types of reinforcing fiber base materials are prepared, a laminated reinforcing fiber base material obtained by laminating these reinforcing fiber base materials, and (3) a fiber bundle (strand) in which the reinforcing fibers are aligned in one direction is bound with a thread ( A plurality of reinforcing fiber base materials prepared by stitching) are prepared, and these reinforcing fiber base materials are superposed so that the fiber directions of the fiber bundles are different from each other. For example, a laminated reinforcing fiber base material integrated (stitched) with is used.

The fiber reinforced plastic is obtained by impregnating a reinforced fiber with a synthetic resin. The reinforcing fibers are bonded and integrated by the impregnated synthetic resin.
The method of 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 the synthetic resin impregnated into the reinforcing fiber, either a thermoplastic resin or a thermosetting resin can be used, and a thermosetting resin is preferably used. The thermosetting resin impregnated into the reinforcing fiber is not particularly limited, and is an epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicone resin, maleimide resin, vinyl ester resin, cyanate ester resin, maleimide. Examples thereof include a resin obtained by prepolymerizing a resin and a cyanate ester resin, and an epoxy resin and a vinyl ester resin are preferable because they are excellent in heat resistance, shock absorption or chemical resistance. 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.

The thermoplastic resin impregnated into the reinforcing fiber is not particularly limited, and examples thereof include olefin resins, polyester resins, thermoplastic epoxy resins, amide resins, thermoplastic polyurethane resins, sulfide resins, acrylic resins, and the like. Polyester resins and thermoplastic epoxy resins are preferred because they are excellent in adhesiveness with the foamed molded article or adhesiveness between the reinforcing fibers constituting the 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 may be a polymer or copolymer of epoxy compounds having a linear structure, or a copolymer of an epoxy compound and a monomer that can be polymerized with the epoxy compound. And a copolymer having a linear 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 An epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin and the like can be mentioned, and a bisphenol A type epoxy resin and a bisphenol fluorene type epoxy resin are preferable. In addition, a thermoplastic epoxy resin may be used independently and 2 or more types may be used together.

Examples of the thermoplastic polyurethane resin include a polymer having a linear structure obtained by polymerizing diol and diisocyanate. Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, and the like. Diols may be used alone or in combination of two or more. Examples of the diisocyanate include aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Diisocyanate may be used independently or 2 or more types may be used together. In addition, a thermoplastic polyurethane resin may be used independently and 2 or more types may be used together.
The content of the synthetic resin in the fiber reinforced plastic is preferably 20 to 70% by weight. When the content is less than 20% by weight, the binding property between the reinforcing fibers and the adhesion between the fiber reinforced plastic and the foamed molded article are insufficient, and the mechanical properties of the fiber reinforced plastic and the mechanical strength of the fiber reinforced composite are obtained. May not be sufficiently improved. When the amount is more than 70% by weight, the mechanical properties of the fiber reinforced plastic may be lowered, 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. A fiber reinforced plastic having a thickness within this range is 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.} A fiber reinforced plastic having a basis weight within this range is excellent in mechanical properties despite being lightweight.

Next, a method for producing a reinforced composite will be described. The method for producing a reinforced composite by laminating and integrating the skin material on the surface of the foam molded body is not particularly limited. For example, (1) the skin material is laminated and integrated on the surface of the foam molded body via an adhesive. (2) A foam-molded article obtained by laminating a fiber-reinforced plastic forming material in which a reinforcing fiber is impregnated with a thermoplastic resin on the surface of the foam-molded article, and using the thermoplastic resin impregnated in the reinforcing fiber as a binder (3) Laminating a fiber reinforced plastic forming material in which a reinforcing fiber is impregnated with an uncured thermosetting resin on the surface of the foam molded body And a method of laminating and integrating the fiber reinforced plastic formed by curing the thermosetting resin with the thermosetting resin impregnated in the reinforcing fiber on the surface of the foam molded body (4) A skin material that is heated and softened is disposed on the surface of the foam molded body, and the skin material is deformed along the surface of the foam molded body as necessary by pressing the skin material against the surface of the foam molded body. However, a method of laminating and integrating on the surface of the foamed molded product, (5) a method generally applied in molding of fiber reinforced plastics, and the like can be mentioned. From the viewpoint that the foamed molded article is excellent in mechanical properties such as load resistance under a high temperature environment, the method (4) can also be suitably used.
Examples of the method used for molding the fiber reinforced plastic include an autoclave method, a hand lay-up method, a spray-up method, a PCM (Prepre Compression Molding) method, an RTM (Resin Transfer Molding) method, a VaRTM (Vacuum Assisted Resin Transfer Transfer). Law.

The fiber reinforced composite thus obtained is excellent in heat resistance, mechanical strength and lightness. Therefore, it can be used in a wide range of applications such as the field of transportation equipment such as automobiles, airplanes, railway vehicles, ships, etc., the household appliances field, the information terminal field, and the furniture field.
For example, the fiber reinforced composite is composed of parts for transportation equipment, parts for transportation equipment including structural parts constituting the main body of transportation equipment (particularly parts for automobiles), windmill blades, robot arms, cushioning materials for helmets, It can be suitably used as an agricultural product box, a transport container such as a thermal insulation container, a rotor blade of an industrial helicopter, or a component packing material.
According to the present invention, there is provided an automotive part composed of the fiber-reinforced composite of the present invention. Examples of the automotive part include a floor panel, a roof, a bonnet, a fender, an under cover, a wheel, a steering wheel, Examples include containers (housings), hood panels, suspension arms, bumpers, sun visors, trunk lids, luggage boxes, seats, doors, cowls and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples. First, measurement methods and evaluation methods in Examples, Reference Examples and Comparative Examples will be described.
(Glass-transition temperature)
The glass transition temperature was measured by the method described in JIS K7121: 1987 “Method for measuring plastic transition temperature”. However, the sampling method and temperature conditions were as follows.
Using a differential scanning calorimeter device DSC 6220 type (manufactured by SII Nano Technology), about 6 mg of the sample was filled so that there was no gap at the bottom of the aluminum measurement container. The sample was heated from 30 ° C. to 220 ° C. at a temperature increase rate of 20 ° C./min under a nitrogen gas flow rate of 20 mL / min. From the DSC curve obtained when the sample was quickly removed after being held for 10 minutes, allowed to cool in an environment of 25 ± 10 ° C., and then heated from 30 ° C. to 220 ° C. at a temperature increase 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 the glass transition temperature”).

(Bulk density and bulk multiple)
The bulk density was measured according to JIS K6911: 1995 “General Test Method for Thermosetting Plastics”. 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 expanded particles (kg / m ³ ) = [weight of measuring cylinder containing sample (kg) −weight of measuring cylinder (kg)] / [capacity of measuring cylinder (m ³ )]
The bulk multiple was a value obtained by integrating (multiplying) the resin density to the reciprocal of the bulk density.

(Bending test: density and maximum point load, stress, displacement and energy)
The load, stress, displacement and energy at the maximum point were measured by a method in accordance with JIS K7221-1: 2006 “Rigid foamed plastics—Bending test—Part 1: Determination of flexural properties”. That is, a rectangular parallelepiped test piece having a length of 20 mm, a width of 25 mm, and a height of 130 mm was cut out from the foamed molded body. For the measurement, a Tensilon universal testing machine ("UCT-10T" manufactured by Orientec Co., Ltd.) was used. The bending maximum point stress of the bending strength was calculated using a universal testing machine data processing system (“UTPS-237S Ver, 1.00” manufactured by Softbrain).
The strip-shaped test piece was placed on a support table, and the maximum bending point stress was measured under the conditions of a load cell 1000N, a test speed of 10 mm / min, a tip jig 5R of the support table, and an opening width of 100 mm. The number of test pieces shall be 5 or more, and the same as JIS K 7100: 1999 symbol “23/50” (temperature 23 ° C., relative humidity 50%) after adjusting the condition over a standard atmosphere of 2nd grade for 16 hours. Measurement was performed under a standard atmosphere. The arithmetic mean value of the bending maximum point stress of each test piece was taken as the bending maximum point stress of the foamed molded product.
Moreover, the bending maximum point stress per unit density was calculated by dividing the bending maximum point stress by the density of the foamed molded product.
In addition, the density (kg / m ³ ) of the foam molded article was obtained by the formula (a) / (b) by measuring the weight (a) and volume (b) of the test piece cut out from the foam molded article.

(Bending test: elastic modulus)
The flexural modulus was measured by a method in accordance with JIS K7221-1: 2006 “Hard foamed plastics—Bending test—Part 1: Determination of flexural properties”. That is, a rectangular parallelepiped test piece having a length of 20 mm, a width of 25 mm, and a height of 130 mm was cut out from the foamed molded body. For the measurement, a Tensilon universal testing machine ("UCT-10T" manufactured by Orientec Co., Ltd.) was used. The flexural modulus was calculated using a universal testing machine data processing system (“UTPS-237S Ver, 1.00” manufactured by Soft Brain). The number of test pieces shall be 5 or more, and the same as JIS K 7100: 1999 symbol “23/50” (temperature 23 ° C., relative humidity 50%) after adjusting the condition over a standard atmosphere of 2nd grade for 16 hours. Measurement was performed under a standard atmosphere. The arithmetic average value of the compression elastic modulus of each test piece was used as the bending elastic modulus of the foamed molded product.
The flexural modulus was calculated by the following equation using the first linear part of the load-deformation curve.
E = Δσ / Δε
E: Flexural modulus (MPa)
Δσ: Stress difference between two points on the straight line (MPa)
Δε: Difference in deformation between the same two points (%)
The flexural modulus per unit density was calculated by dividing the flexural modulus by the density of the foamed molded product.

(Compression test: density and 5%, 10% and 25% stress)
The 5% compressive stress, 10% compressive stress, and 25% compressive stress of the foam molded article were measured by the method described in JIS K7220: 2006 “Rigid Foamed Plastics—How to Obtain Compression Properties”. That is, using a Tensilon universal testing machine ("UCT-10T" manufactured by Orientec Co., Ltd.) and a universal testing machine data processing system ("UTPS-237S Ver, 1.00" manufactured by Softbrain), the specimen size cross section is 50 mm. The compression strength (5% deformation compression stress, 25% deformation compression stress, compression elastic modulus) was measured with a compression rate of 2.5 mm / min with a thickness of 50 mm and a thickness of 25 mm. The number of specimens shall be 5 or more, and the same as JIS K 7100: 1999 symbol “23/50” (temperature 23 ° C., relative humidity 50%) after adjusting the condition for 16 hours under a second grade standard atmosphere. Measurements were performed under a standard atmosphere. The arithmetic mean values of the compressive strength (5% deformation compression stress, 10% deformation compression stress, 25% deformation compression stress) of each test piece are respectively 5% compression stress, 10% compression stress, and 25% of the foam molded article. Compressive stress was assumed.
(5% (10%, 25%) deformation compressive stress)
5% (10%, 25%) deformation compressive stress was calculated by the following equation. The values in parentheses are the conditions for calculating 10% deformation compression stress and 25% deformation compression stress.
σ5 (10, 25) = F5 (10, 25) / A ₀
σ5 (10, 25): 5% (10%, 25%) Deformation compressive stress (MPa)
F5 (10, 25): 5% (10%, 25%) Deformation force (N)
A ₀ : Initial cross-sectional area of the test piece (mm ² )
The 5% deformation compressive stress per unit density was calculated by dividing the 5% deformation compressive stress by the density of the foamed molded product.

(Compression test: elastic modulus)
The compression modulus of the foamed molded product was measured by the method described in JIS K7220: 2006 “Hard foamed plastics—How to obtain compression characteristics”. That is, using a Tensilon universal testing machine ("UCT-10T" manufactured by Orientec Co., Ltd.) and a universal testing machine data processing system ("UTPS-237S Ver, 1.00" manufactured by Softbrain), the specimen size cross section is 50 mm. The compression elastic modulus was measured at a compression speed of 2.5 mm / min with × 50 mm and a thickness of 25 mm. The number of specimens shall be 5 or more, and the same as JIS K 7100: 1999 symbol “23/50” (temperature 23 ° C., relative humidity 50%) after adjusting the condition for 16 hours under a second grade standard atmosphere. Measurements were performed under a standard atmosphere. The arithmetic average value of the compression elastic modulus of each test piece was used as the compression elastic modulus of the foamed molded article.
(Compressive modulus)
The compression elastic modulus was calculated by the following equation using the first linear portion of the load-deformation curve.
E = Δσ / Δε
E: Compression modulus (MPa)
Δσ: Stress difference between two points on the straight line (MPa)
Δε: Difference in deformation between the same two points (%)
Further, the compression elastic modulus per unit density was calculated by dividing the compression elastic modulus by the density of the foamed molded product.

(Ratio of resin component of base resin)
( ¹ H-NMR)
Measurement was performed under the following conditions using an ECX400P nuclear magnetic resonance apparatus manufactured by JEOL.
<Measurement conditions>
・ Measurement mode Single pulse ・ Pulse width 45 ° (6.05μsec)
・ Number of points 32k
・ Repetition time: 7.0 seconds ・ Number of integrations: 128 times ・ Measurement solvent: Deuterated chloroform ・ Sample concentration: Approx. 20 mg / 0.6 mL
・ Measurement temperature 50 ℃
・ Chemical shift standard Chloroform: 7.24ppm
・ Measurement range: 20ppm (-5ppm to 15ppm)
-Window function exponential (BF: 0.12 Hz)
The composition ratio of the base resin was calculated from the integrated intensity ratio of each signal in the spectrum obtained from ¹ H-NMR measurement. In addition, when signals presumed to be derived from impurities were observed in each signal region, these contributions were ignored in the calculation.

(FT-IR)
The absorbance ratio (D1780 / D698, D1720 / D698) of the base resin was measured as follows.
Each of 10 randomly selected resin particles was subjected to surface analysis by an infrared spectroscopic analysis ATR measurement method to obtain an infrared absorption spectrum. In this analysis, an infrared absorption spectrum having a depth ranging from the sample surface to several μm (about 2 μm) was obtained. The absorbance ratio (D1780 / D698, D1720 / D698) was calculated from each infrared absorption spectrum, and the arithmetic average of the calculated absorbance ratio was used as the absorbance ratio.
Absorbances D1780, D1720, and D698 are connected to a measuring device sold by Thermo SCIENTIFIC under the trade name “Fourier Transform Infrared Spectrophotometer Nicolet iS10” by connecting “Smart-iTR” manufactured by Thermo SCIENTIFIC as an ATR accessory. It was measured. Infrared spectroscopic analysis ATR measurement was performed under the following conditions.

<Measurement conditions>
Measurement apparatus: Fourier transform infrared spectrophotometer Nicolet iS10 (manufactured by Thermo SCIENTIFIC) and single reflection type horizontal ATR Smart-iTR (manufactured by Thermo SCIENTIFIC)
ATR crystal: Diamond with ZnSe lens, angle = 42 °
Measurement method: Single ATR method Measurement wave number range: 4000 cm ⁻¹ to 650 cm ⁻¹
-Wave depth dependence of measurement depth: No correction-Detector: Triglycine deuterated sulfate (DTGS) detector and KBr beam splitter-Resolution: 4 cm ^-1
・ Number of integration: 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. The measurement was performed.
The infrared absorption spectrum obtained under the above conditions was subjected to peak processing as follows to obtain D1780, D1720, and D698, respectively.
The absorbance D1780 at 1780 cm ⁻¹ obtained from the infrared absorption spectrum meant the absorbance corresponding to the absorption spectrum derived from the antisymmetric stretching vibration due to C═O of the two carbonyl groups in maleic anhydride.
In this measurement of absorbance, peak separation was not 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 the baseline, were mean maximum absorbance between 1810 cm ^-1 and 1745 cm ^-1.

Further, the absorbance D1720 at 1720 cm ⁻¹ meant the absorbance corresponding to the absorption spectrum derived from the antisymmetric stretching vibration caused by the carbonyl group C═O contained in methyl methacrylate.
In this absorbance measurement, 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 the baseline, were mean maximum absorbance between 1745 cm ^-1 and 1690 cm ^-1.
Absorbance D698 at 698 cm ⁻¹ meant the absorbance corresponding to the absorption spectrum derived from the out-of-plane bending vibration of C—H in the monosubstituted benzene ring in styrene.
In this absorbance measurement, peak separation was not 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 had mean maximum absorbance between 720 cm ^-1 and 660 cm ^-1.

The ratio of styrene, methyl methacrylate and maleic anhydride (% by weight) was calculated from the absorbance ratio (D1780 / D698, D1720 / D698) based on the calibration curve described later. In addition, the peak processing method used the method similar to the above-mentioned resin particle.
As a method for determining the composition ratio of styrene and methyl methacrylate from the absorbance ratio, a plurality of types of standard samples prepared by uniformly mixing styrene resin and methyl methacrylate resin at a predetermined composition ratio were prepared.
Specifically, monomers measured by weight ratios of methyl methacrylate and styrene at a weight ratio of 0/100, 20/80, 40/60, 50/50, and 60/40, respectively, are placed in a 10 ml screw vial. 10 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to 100 parts by weight of the monomer to dissolve the monomer. The obtained mixed solution was transferred to a 2 ml sample tube (φ7 mm × 122 mm × 190 mm), purged with nitrogen, and sealed. Next, this was put into a water bath set at 65 ° C. and heated for 10 hours to complete the polymerization, and the polymer taken out from the ampule was used as a standard sample.
After obtaining an infrared absorption spectrum for each standard sample by the infrared spectroscopic analysis ATR method, an absorbance ratio (D1780 / D698) was calculated. A calibration curve was drawn by taking the composition ratio (styrene resin ratio in the standard sample = wt%) 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 could be determined.

As standard samples of styrene resin and maleic anhydride resin, a 1/1 copolymer of styrene and maleic anhydride (trade name “SMA1000 (P)”, manufactured by CRAY VALLEY) and 3 of styrene and maleic anhydride are used. / 1 copolymer (trade name “SMA3000 (P)”, manufactured by CRAY VALLEY) was used.
After obtaining an infrared absorption spectrum for each standard sample by the infrared spectroscopic analysis ATR method, an absorbance ratio (D1720 / D698) was calculated. A calibration curve was drawn by taking the composition ratio (styrene resin ratio in the standard sample = wt%) 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 could be determined.
The composition ratios of styrene and methyl methacrylate and styrene and maleic anhydride were determined from the calibration curves. From each composition ratio, the composition ratio of the three components of styrene, methyl methacrylate, and maleic anhydride in the resin was 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 ratio C in [2] was matched with the styrene ratio B in [1].
From [2] Styrene: Maleic anhydride = C: D
= C x (B / C): D x (B / C)
= B: D × (B / C) [3]
From [3], since the ratio of styrene becomes equal to [1], the abundance ratio of methyl methacrylate, styrene, and maleic anhydride is as follows from [1] and [3].
Methyl methacrylate: styrene: maleic anhydride = A: B: D × (B / C) [4]
From the abundance ratio of [4], the ratio of each component was as follows.
Methyl methacrylate = {A / ((A + B + D × (B / C))} × 100
Styrene = {B / ((A + B + D × (B / C))} × 100
Maleic anhydride = {D × (B / C) / ((A + B + D × (B / C))} × 100

(Bubble count)
The number of bubbles in the expanded particles and the expanded molded body was measured in the following manner. First, an area of 11.9 mm ² was photographed at a magnification of 30 with a scanning electron microscope (“SU1510” manufactured by Hitachi High-Technologies Corporation). For the foamed particles, the central part of the cross-section substantially divided into two at the central part of the foamed particles was photographed. The photographed image was printed on A4 paper, and the average bubble diameter was calculated for all bubbles. In addition, the bubble diameter measured the long diameter and short diameter of the bubble cross section, and made it the value obtained by the arithmetic mean value of a short diameter and a long diameter. Specifically, two arbitrary points having the maximum mutual distance on the outer contour line of the bubble cross section were selected, and the distance between the two points was defined as the “bubble major diameter”. Also, any two points where the mutual distance is maximum are selected from any two points where the straight line perpendicular to the major axis of the bubble and the outer contour line of the bubble cross section intersect, and the distance between the two points is expressed as “ The short diameter of the bubbles ”. The number of individual bubbles was counted on the paper for small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less.
Each of the nine foam particles and the molded foam is cut in the same manner as described above to obtain enlarged photographs. Based on these enlarged photographs, the number of small bubbles and the individual bubbles of large bubbles are obtained in the same manner as described above. Numbers were calculated. The arithmetic average value of 10 individual bubbles was defined as the number of bubbles.

(Average bubble diameter of large and small bubbles)
The average bubble diameter of large bubbles and the average bubble diameter of small bubbles were measured by the following methods, respectively.
The average cell diameter of the large bubbles is the scanning electron microscope ("SU1510" manufactured by Hitachi High-Technologies Corporation) on the center part of the cross-section substantially divided into two at the center part of the foamed particle for the foamed particles and any cut surface for the molded product. Was used to photograph an area of 11.9 mm ² at 30 ×. The photographed image was printed on A4 paper, and the bubble diameter was calculated for all large bubbles. In addition, the bubble diameter measured the long diameter and short diameter of the bubble cross section, and made it the value obtained by the arithmetic mean value of a short diameter and a long diameter. Specifically, two arbitrary points having the maximum mutual distance on the outer contour line of the bubble cross section were selected, and the distance between the two points was defined as the “bubble major diameter”. Also, any two points where the mutual distance is maximum are selected from any two points where the straight line perpendicular to the major axis of the bubble and the outer contour line of the bubble cross section intersect, and the distance between the two points is expressed as “ The short diameter of the bubbles ”.
Nine foamed particles and foamed molded body were cut in the same manner as described above to obtain enlarged photographs, and the average bubble diameter of large bubbles was calculated in the same manner as described above based on these enlarged photographs. The arithmetic average value of the bubble diameters of the large bubbles in the 10 photographs was taken as the average bubble diameter.
The average bubble diameter of the small bubbles is determined by using a scanning electron microscope ("SU1510" manufactured by Hitachi High-Technologies Corporation) at the center of the cross-section substantially divided into two at the center for the foamed particles and an arbitrary cut surface for the molded product. I took a picture.
At this time, the micrograph was taken so as to have a predetermined magnification when printed in a state in which two images (total of four images in total) were aligned on one A4 paper in landscape orientation. Specifically, when an arbitrary straight line of 60 mm is drawn on the image printed as described above, parallel to each of the vertical direction (the vertical direction of the image) and the horizontal direction (the horizontal direction of the image), The magnification in the electron microscope was adjusted so that the number of bubbles present on an arbitrary straight line was about 10-50. Two cross-sectional micrographs were taken for each section of the two expanded particles, and printed on A4 paper as described above.
Three arbitrary straight lines (length 60 mm) parallel to the vertical and horizontal directions were drawn on each of the two images of the expanded particle cross section, and six arbitrary straight lines were drawn in each direction.

In addition, an arbitrary straight line does not contact a large bubble, and the bubble is prevented from touching only at the contact point as much as possible. In the case where it comes into contact, this bubble is also added to the number. The number of bubbles counted for six arbitrary straight lines in each of the vertical and horizontal directions was arithmetically averaged to obtain the number of bubbles in each direction.
From the magnification of the image obtained by counting the number of bubbles and the number of bubbles, the average chord length (t) of the bubbles was calculated by the following equation.
Average chord length t (mm) = 60 / (number of bubbles × photo magnification)
The magnification of the image was determined by measuring the scale bar on the photograph to 1/100 mm with “Digimatic Caliper” manufactured by Mitutoyo Co., Ltd.
Image magnification = Scale bar measured value (mm) / Scale bar display value (mm)
And the bubble diameter in each direction was computed by following Formula.
Bubble diameter D (mm) = t / 0.616
Further, the square root of the product was taken as the average bubble diameter of small bubbles.
Average bubble diameter of small bubbles (mm) = (D vertical x D horizontal) ^1/2

(Thermal conductivity)
The thermal conductivity is measured by using a thermal conductivity measuring device HC-074 / 200 (Auto Λ) manufactured by Eiko Seiki Co., Ltd., JIS A1412-2 “Measurement method of thermal resistance and thermal conductivity of thermal insulation material—Part 2: The measurement was carried out by the method described in “Heat flow meter method (HFM method)”. A test piece having a length of 200 mm, a width of 200 mm, and a thickness of 30 mm cut out from the foam molded article was allowed to stand under standard conditions of a temperature of 23 ° C. ± 2 ° C. and a humidity of 50% ± 5% for 24 hours. The thermal conductivity was measured by the above thermal conductivity measuring device under the conditions of a temperature of 23 ° C. (a high temperature side plate temperature of 38 ° C., a low temperature side plate temperature of 8 ° C.) and a temperature difference of 30 ° C. NIST (National Institute of Standards and Technology) SRM1450B registered in the thermal conductivity measuring apparatus was adopted as a reference value for calibration.

Example 1a
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from the die hole (5 nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 285 ° C., inlet side resin pressure: 13 MPa) attached to the tip of the single screw extruder. The resin particles were produced by extruding into the housed chamber, rotating the rotary shaft of the rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying. . The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.1 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred with water vapor at a foaming temperature of 143 ° C. for 50 seconds. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained expanded particles was measured by the method described above, it was 102 kg / m ³ (expanding ratio 10 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled in a 30 mm x 300 mm x 400 mm mold, heated with 0.38 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.

Example 2a
(Foaming step) In the same manner as in Example 1a except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 143 ° C. for 60 seconds, the foaming density was 61 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.

(Example 3a)
(Foaming step) In the same manner as in Example 1a except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the foaming temperature was 143 ° C. while stirring for 55 seconds, the foaming density was 74 kg / kg. Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.

(Comparative Example 1a)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight was supplied to a twin screw extruder having a diameter of 30 mm at a rate of 6 kg / hr per hour, and melt kneaded at 250 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. The cooled strand-shaped resin was sufficiently drained and then 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.
Except that the obtained resin particles are used, the foamed particles are subjected to (impregnation step), (foaming step) and (molding step) in the same manner as in Example 1a and have a foaming density of 108 kg / m ³ (foaming ratio: 10 times). A foamed molded product was obtained.

(Comparative Example 2a)
(Foaming step) In the same manner as in Comparative Example 1a except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 143 ° C. for 60 seconds, a foaming density of 60 kg / Expanded particles of m ³ (20 times expansion ratio) were obtained.
Except using the obtained resin particle, it attached | subjected to the (molding process) like Example 1a, and obtained the foaming molding.
Table 1 summarizes the physical properties of the expanded particles and expanded molded articles of Examples 1a to 3a and Comparative Examples 1a to 2a.
1 and 2 show cross-sectional photographs of the expanded particles and the expanded molded articles of Examples 1a to 3a and Comparative Examples 1a to 2a, respectively.

From Table 1, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

Example 4a
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-200”, manufactured by Denka Co., Ltd., styrene: 55 parts by weight, methyl methacrylate: 26 parts by weight, maleic anhydride: 19 parts by weight, density 1.16 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 260 ° C. Subsequently, cooling water at about 70 ° C. was poured from the die hole (five nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 280 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles were produced by extruding into the housed chamber, rotating the rotary shaft of the rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying. . The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and then 0.1 part by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred at a foaming temperature of 131 ° C. for 50 seconds using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained foamed particles was measured by the above-described method, it was 105 kg / m ³ (foaming ratio 10 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.30 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.

(Example 5a)
(Foaming step) In the same manner as in Example 4a, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 131 ° C. for 70 seconds, the foaming density was 52 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.
Table 2 summarizes the physical properties of the foamed particles and foamed molded products of Examples 4a and 5a.
Moreover, the cross-sectional photograph of the expanded particle of Example 4a and 5a and a foaming molding is shown in FIG.

From Table 2, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

Example 6a
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, manufactured by Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight is 85 parts by weight, and the remaining 15 parts by weight is a styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, manufactured by Denka Co., Ltd.) 100 parts by weight of styrene: 58 parts by weight, maleic anhydride: 4 parts by weight, N-phenylmaleimide: 38 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) was 10 kg / hr per hour. The mixture was supplied to a single screw extruder having a diameter of 40 mm and melt-kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from a die hole (5 nozzles with a diameter of 0.8 mm arranged) of a die (temperature: 285 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles were produced by extruding into the housed chamber, rotating the rotary shaft of the rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying. . The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.1 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while stirring for 80 seconds at a foaming temperature of 145 ° C. using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained expanded particles was measured by the method described above, it was 104 kg / m ³ (expanding ratio 10 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After removal, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.45 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product drops to 0.05 MPa. Thus, a foamed molded product was obtained.

(Example 7a)
(Foaming step) In the same manner as in Example 6a, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 145 ° C. for 90 seconds, a foaming density of 72 kg / Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.

Example 8a
(Foaming step) In the same manner as in Example 6a except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 145 ° C. for 100 seconds, a foaming density of 47 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.
Table 3 summarizes the physical properties of the foamed particles and foamed molded products of Examples 6a to 8a.
Further, cross-sectional photographs of the expanded particles and the expanded molded articles of Examples 6a to 8a are shown in FIG.

From Table 3, it can be seen that the foam-molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

(Example 1b)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from the die hole (5 nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 285 ° C., inlet side resin pressure: 13 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.15 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred for 55 seconds at a foaming temperature of 143 ° C. using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained foamed particles was measured by the method described above, it was 74 kg / m ³ (foaming ratio 15 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled in a 30 mm x 300 mm x 400 mm mold, heated with 0.38 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.

(Example 2b)
(Foaming step) In the same manner as in Example 1b except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 143 ° C. for 60 seconds. An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.
Table 4 shows the physical properties of the foamed particles and foamed molded products of Examples 1b and 2b.
Moreover, the cross-sectional photograph of the expanded particle of Example 1b and 2b and a foaming molding is shown in FIG.

From Table 4, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent heat insulating properties.

(Example 3b)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-200”, manufactured by Denka Co., Ltd., styrene: 55 parts by weight, methyl methacrylate: 26 parts by weight, maleic anhydride: 19 parts by weight, density 1.16 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 260 ° C. Subsequently, cooling water at about 70 ° C. was poured from the die hole (five nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 280 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and then 0.1 part by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred for 70 seconds at a foaming temperature of 131 ° C. using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained foamed particles was measured by the method described above, it was 52 kg / m ³ (foaming ratio 20 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.30 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.
Table 5 shows the physical properties of the expanded particles and the molded foam of Example 3b.
Moreover, the cross-sectional photograph of the expanded particle of Example 3b and a foaming molding is shown in FIG.

From Table 5, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent heat insulation.

(Example 4b)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, manufactured by Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight is 85 parts by weight, and the remaining 15 parts by weight is a styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, manufactured by Denka Co., Ltd.) 100 parts by weight of styrene: 58 parts by weight, maleic anhydride: 4 parts by weight, N-phenylmaleimide: 38 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) was 10 kg / hr per hour. The mixture was supplied to a single screw extruder having a diameter of 40 mm and melt-kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from a die hole (5 nozzles with a diameter of 0.8 mm arranged) of a die (temperature: 285 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.15 part by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred for 100 seconds at a foaming temperature of 145 ° C. using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained expanded particles was measured by the method described above, it was 47 kg / m ³ (expanding ratio 20 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After removal, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.45 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product drops to 0.05 MPa. Thus, a foamed molded product was obtained.
Table 6 shows the physical properties of the expanded particles and the expanded molded article of Example 4b.
Moreover, the cross-sectional photograph of the expanded particle of Example 4b and a foaming molding is shown in FIG.

From Table 6, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent heat insulating properties.

(Reference Example 1b)
(Foaming step) In the same manner as in Example 1b except that 0.1 parts by weight of ethylenebisstearic acid amide was added and the mixture was stirred for 50 seconds at a foaming temperature of 143 ° C., the foaming density was 102 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 10 times) were obtained.

(Reference Example 2b)
(Foaming step) In the same manner as in Example 3b except that 0.1 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 145 ° C. for 80 seconds. An expanded particle and an expanded molded body of m ³ (expanding ratio 10 times) were obtained.

(Reference Example 3b)
(Foaming step) In the same manner as in Example 3b except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the mixture was foamed with stirring at a foaming temperature of 145 ° C. for 90 seconds. Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.

(Reference Example 4b)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY KX-406”, manufactured by Denka Co., Ltd., styrene: 70 parts by weight, methyl methacrylate: 9 parts by weight, maleic anhydride: 21 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight and 1 part by weight of a resin composition containing talc were supplied to a twin screw extruder having a diameter of 30 mm and melt-kneaded at 254 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. The cooled strand-shaped resin was sufficiently drained and then 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)
After sealing 100 parts by weight of the resin particles in a pressure vessel and replacing the inside of the pressure vessel with carbon dioxide, the carbon dioxide was press-fitted to an impregnation pressure of 1.0 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.08 part by weight of calcium carbonate was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while stirring for 150 seconds at a foaming temperature of 136 ° C. using water vapor. After foaming, the particles were taken out from the high-pressure foaming tank, and after removing calcium carbonate with an aqueous hydrogen chloride solution, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained expanded particles was measured by the method described above, it was 104 kg / m ³ . When a cross-sectional photograph of the expanded particles was confirmed, no large bubbles were present.

(Molding process)
The obtained 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, the carbon dioxide was added to an impregnation pressure (gauge pressure) of 0.4 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.42 MPa water vapor for 60 seconds, and then cooled until the maximum surface pressure of the foamed molded product decreases to 0.01 MPa. Thus, a foamed molded product was obtained.
Table 7 shows the physical properties of the expanded particles and the expanded molded articles of Reference Examples 1b to 4b.
Further, FIG. 8 shows cross-sectional photographs of the expanded particles and expanded molded articles of Reference Examples 1b to 3b.

(Example 1c)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from the die hole (5 nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 285 ° C., inlet side resin pressure: 13 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Example 2c)
(Foaming step) In the same manner as in Example 1c except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the foaming temperature was 143 ° C. while stirring for 55 seconds, the foaming density was 74 kg / kg. Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.
Table 8 shows the physical properties of the expanded particles and the expanded molded articles of Examples 1c and 2c.
Moreover, the cross-sectional photograph of the expanded particle of Example 1c and 2c and a foaming molding is shown in FIG.

From Table 8, it can be seen that the foam molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

(Example 3c)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-200”, manufactured by Denka Co., Ltd., styrene: 55 parts by weight, methyl methacrylate: 26 parts by weight, maleic anhydride: 19 parts by weight, density 1.16 g / cm ³ ) 100 parts by weight was supplied to a single screw extruder having a diameter of 40 mm at a rate of 10 kg / hr per hour, and melt kneaded at 260 ° C. Subsequently, cooling water at about 70 ° C. was poured from the die hole (five nozzles with a diameter of 0.8 mm arranged) of the die (temperature: 280 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Impregnation process)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and then 0.1 part by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred at a foaming temperature of 131 ° C. for 50 seconds using water vapor. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained foamed particles was measured by the above-described method, it was 105 kg / m ³ (foaming ratio 10 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.30 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.
Table 9 shows the physical properties of the expanded particles and the molded foam of Example 3c.
Moreover, the cross-sectional photograph of the expanded particle of Example 3c and a foaming molding is shown in FIG.

From Table 9, it can be seen that the foam-molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

(Example 4c)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, manufactured by Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight is 85 parts by weight, and the remaining 15 parts by weight is a styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, manufactured by Denka Co., Ltd.) 100 parts by weight of styrene: 58 parts by weight, maleic anhydride: 4 parts by weight, N-phenylmaleimide: 38 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) was 10 kg / hr per hour. The mixture was supplied to a single screw extruder having a diameter of 40 mm and melt-kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from a die hole (5 nozzles with a diameter of 0.8 mm arranged) of a die (temperature: 285 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles are extruded by being extruded into the housed chamber, rotating the rotary shaft of a rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying the resin particles. Produced. The obtained resin particles had an average particle diameter of 1.2 mm.

(Example 5c)
(Foaming step) In the same manner as in Example 4c, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 145 ° C. for 90 seconds, a foaming density of 72 kg / Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.
Table 10 shows the physical properties of the foamed particles and foamed molded products of Examples 4c to 5c.
Further, FIG. 11 shows cross-sectional photographs of the expanded particles and the expanded molded articles of Examples 4c to 5c.

From Table 10, it can be seen that the foamed molded product obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

(Reference Example 1c)
(Foaming step) In the same manner as in Example 1c except that 0.15 parts by weight of ethylenebisstearic acid amide was added and the foaming temperature was 143 ° C. with stirring for 60 seconds, the foaming density 61 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.

(Reference Example 2c)
(Foaming step) In the same manner as in Example 3c, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 131 ° C. for 70 seconds, the foaming density was 52 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.

(Reference Example 3c)
(Foaming step) In the same manner as in Example 4c, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 145 ° C. for 100 seconds, a foaming density of 47 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.

(Reference Example 4c)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY KX-406”, manufactured by Denka Co., Ltd., styrene: 70 parts by weight, methyl methacrylate: 9 parts by weight, maleic anhydride: 21 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight and 1 part by weight of a resin composition containing talc were supplied to a twin screw extruder having a diameter of 30 mm and melt-kneaded at 254 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. The cooled strand-shaped resin was sufficiently drained and then 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.

(Molding process)
The obtained 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, the carbon dioxide was added to an impregnation pressure (gauge pressure) of 0.4 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.42 MPa water vapor for 60 seconds, and then cooled until the maximum surface pressure of the foamed molded product decreases to 0.01 MPa. Thus, a foamed molded product was obtained.
Table 11 shows the physical properties of the expanded particles and the expanded molded articles of Reference Examples 1c to 4c.
FIG. 12 shows cross-sectional photographs of the expanded particles and the expanded molded articles of Reference Examples 1c to 3c.

Example 1d
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ , glass transition temperature Tg 143 ° C.) 85 parts by weight, styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, Denka, styrene: 67 parts by weight 100 parts by weight of maleic anhydride: 5 parts by weight, N-phenylmaleimide: 27 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) 15 parts by weight at a rate of 10 kg / hr per hour The mixture was supplied to a single screw extruder having a diameter of 40 mm and melt kneaded at 270 ° C. Subsequently, about 70 ° C. cooling water is supplied from a die hole (5 nozzles with a diameter of 0.8 mm arranged) of a die (temperature: 285 ° C., inlet side resin pressure: 14 MPa) attached to the tip of the single screw extruder. The resin particles were produced by extruding into the housed chamber, rotating the rotary shaft of the rotary blade having six cutting blades at a rotational speed of 5000 rpm, cutting into granules, cooling with the cooling water, and dehydrating and drying. . The obtained resin particles had an average particle diameter of 1.2 mm.

(Example 2d)
(Foaming step) In the same manner as in Example 1d, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 145 ° C. for 90 seconds, a foaming density of 72 kg / Expanded particles of m ³ (foaming ratio 15 times) and foamed molded articles were obtained.

(Example 3d)
(Foaming step) In the same manner as in Example 1d, except that 0.15 parts by weight of ethylenebisstearic acid amide was added and stirring was performed at a foaming temperature of 145 ° C. for 100 seconds, a foaming density of 47 kg / An expanded particle and an expanded molded body of m ³ (expanding ratio 20 times) were obtained.
Table 12 summarizes the physical properties of the expanded particles and expanded molded articles of Examples 1d to 3d.
FIG. 13 shows cross-sectional photographs of the foamed particles and foamed molded products of Examples 1d to 3d.

From Table 12, it can be seen that the foamed molded article obtained from the foamed particles having a specific range of bubbles has excellent mechanical properties.

(Reference Example 1d)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-200”, manufactured by Denka Co., Ltd., styrene: 55 parts by weight, methyl methacrylate: 26 parts by weight, maleic anhydride: 19 parts by weight, density 1.16 g / cm ³ , glass transition temperature Tg 130 ° C.) 85 parts by weight, styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, Denka, styrene: 67 parts by weight 100 parts by weight of maleic anhydride: 5 parts by weight, N-phenylmaleimide: 27 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) 15 parts by weight at a rate of 6 kg / hr per hour The mixture was supplied to a twin screw extruder having a diameter of 30 mm and melt kneaded at 250 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin composition was immediately cooled in a cooling water bath. The cooled strand-shaped resin composition was sufficiently drained and then 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)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.1 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred at a foaming temperature of 130 ° C. for 80 seconds using water vapor, but foamed particles could not be obtained. Further, even if the foaming temperature was changed to either 135 ° C. or 145 ° C., foamed particles could not be obtained.

(Reference Example 2d)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-100”, manufactured by Denka Co., Ltd., styrene: 64 parts by weight, methyl methacrylate: 23 parts by weight, maleic anhydride: 12 parts by weight, density 1.14 g / cm ³ , 85 parts by weight of glass transition temperature Tg 120 ° C., styrene-maleic anhydride-N-phenylmaleimide copolymer (trade name “DENKA IP MS-NIP”, Denka Co., styrene: 67 parts by weight 100 parts by weight of maleic anhydride: 5 parts by weight, N-phenylmaleimide: 27 parts by weight, density 1.18 g / cm ³ , glass transition temperature Tg 186 ° C.) 15 parts by weight at a rate of 6 kg / hr per hour The mixture was supplied to a twin screw extruder having a diameter of 30 mm and melt kneaded at 250 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin composition was immediately cooled in a cooling water bath. The cooled strand-shaped resin composition was sufficiently drained and then 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)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.1 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred at a foaming temperature of 120 ° C. for 80 seconds using water vapor, but foamed particles could not be obtained. Further, even if the foaming temperature was changed to any of 125 ° C, 130 ° C, 135 ° C and 145 ° C, foamed particles could not be obtained.
Table 13 summarizes the glass transition temperature differences of Reference Examples 1d to 2d.

From Table 13, it can be seen that when the glass transition temperature difference is outside the range of 10 to 50 ° C., it is difficult to obtain expanded particles capable of producing the expanded molded article.

(Reference Example 3d)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY R-310”, Denka Co., Ltd., styrene: 62 parts by weight, methyl methacrylate: 12 parts by weight, maleic anhydride: 26 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight was supplied to a twin screw extruder having a diameter of 30 mm at a rate of 6 kg / hr per hour, and melt kneaded at 250 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. The cooled strand-shaped resin was sufficiently drained and then 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)
After 100 parts by weight of the resin particles were sealed in a pressure vessel and the inside of the pressure vessel was replaced with carbon dioxide, carbon dioxide was injected to an impregnation pressure (gauge pressure) of 0.7 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.1 parts by weight of ethylenebisstearic acid amide was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while being stirred with water vapor at a foaming temperature of 143 ° C. for 50 seconds. After foaming, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained expanded particles was measured by the method described above, it was 102 kg / m ³ (expanding ratio 10 times).
(Molding process)
The obtained 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, the carbon dioxide was reduced to an impregnation pressure (gauge pressure) of 0.5 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled in a 30 mm x 300 mm x 400 mm mold, heated with 0.38 MPa water vapor for 20 seconds, and then cooled until the maximum surface pressure of the foamed molded product is reduced to 0.05 MPa. Thus, a foamed molded product was obtained.
Moreover, the cross-sectional photograph of the expanded particle of Example 3d and a foaming molding is shown in FIG. 14, respectively.

(Reference Example 4d)
(Resin particle manufacturing process)
Styrene-methyl methacrylate-maleic anhydride copolymer (trade name “DENKA RESISFY KX-406”, manufactured by Denka Co., Ltd., styrene: 70 parts by weight, methyl methacrylate: 9 parts by weight, maleic anhydride: 21 parts by weight, density 1.15 g / cm ³ ) 100 parts by weight and 1 part by weight of a resin composition containing talc were supplied to a twin screw extruder having a diameter of 30 mm and melt-kneaded at 254 ° C. Subsequently, the resin composition was extruded from each nozzle of a multi-nozzle mold (20 nozzles having a diameter of 1.0 mm arranged in a circle) attached to the front end of the twin-screw extruder. The extruded resin was immediately cooled in a cooling water bath. The cooled strand-shaped resin was sufficiently drained and then 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)
After sealing 100 parts by weight of the resin particles in a pressure vessel and replacing the inside of the pressure vessel with carbon dioxide, the carbon dioxide was press-fitted to an impregnation pressure of 1.0 MPa. After leaving still at 20 degreeC environment and 24 hours of impregnation time passed, the pressure vessel was pressure-removed slowly over 5 minutes. In this way, resin particles were impregnated with carbon dioxide gas to obtain expandable particles.
(Foaming process)
Immediately after the pressure removal in the impregnation step, the foamable particles were taken out from the pressure vessel, and 0.08 part by weight of calcium carbonate was added and mixed. Thereafter, the impregnated product was foamed with water vapor in a high-pressure foaming tank while stirring for 150 seconds at a foaming temperature of 136 ° C. using water vapor. After foaming, the particles were taken out from the high-pressure foaming tank, and after removing calcium carbonate with an aqueous hydrogen chloride solution, drying was performed with an air dryer to obtain foamed particles. When the bulk density of the obtained foamed particles was measured by the method described above, it was 0.12 g / cm ³ .

(Molding process)
The obtained 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, the carbon dioxide was added to an impregnation pressure (gauge pressure) of 0.4 MPa. Press-fitted. It left still in a 20 degreeC environment, and pressure curing was implemented for 8 hours. After taking out, it is filled into a 30 mm x 300 mm x 400 mm mold, heated with 0.42 MPa water vapor for 60 seconds, and then cooled until the maximum surface pressure of the foamed molded product decreases to 0.01 MPa. Thus, a foamed molded product was obtained.
Table 14 summarizes the physical properties of the expanded particles and expanded molded articles of Reference Examples 3d to 4d.

From Tables 12 and 14, it can be seen that when the copolymer B is included, the mechanical properties are improved as compared with the case where the copolymer B is not included.

Claims

Expanded particles composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and the expanded particles have an area of 11.9 mm 2 by 30 times 2 is a foamed particle comprising small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less.
The foamed particle according to claim 1, wherein the foamed particle has only one large bubble in one of them.
The aromatic vinyl is a styrene monomer, the (meth) acrylic acid ester is a (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), and the unsaturated dicarboxylic acid is 2 to 6 carbon atoms. Each selected from an aliphatic unsaturated dicarboxylic acid, and the copolymer is 100 parts by weight of the total of units derived from the aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, 30 to 80 parts by weight of units derived from the aromatic vinyl, 8 to 35 parts by weight of units derived from the (meth) acrylic acid ester, and 10 to 50 parts by weight of units derived from the unsaturated dicarboxylic acid The expanded particle according to claim 1.
The difference between the average bubble diameter of the small bubbles and the average bubble diameter of the large bubbles is 1450 μm or more, and the foamed particles have a heat of 0.0350 W / m · K or less in the foamed molded body constituted by the fused body The expanded particle according to claim 1, which provides conductivity.
Expanded particles composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and the expanded particles have an area of 11.9 mm 2 by 30 times The difference between the average bubble size of the small bubbles and the average bubble size of the large bubbles is provided with small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less. The foamed particle according to claim 1, wherein the foamed particle gives a maximum point stress by a bending test of 1.0 MPa or more to the foamed molded body composed of the fused body.
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 di (meth) acrylate of bisphenol A and Selected from the propylene oxide adduct di (meth) acrylate of bisphenol A,
The (meth) acrylic acid ester is selected from methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and butyl (meth) acrylate;
The expanded particle according to claim 1, wherein the unsaturated dicarboxylic acid is selected from maleic acid, itaconic acid, citraconic acid, aconitic acid, and anhydrides thereof.
Copolymer A of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid, and copolymer B of aromatic vinyl, unsaturated dicarboxylic acid, and unsaturated dicarboxylic imide Expanded particles composed of a base resin, the difference between the glass transition temperature A of the copolymer A and the glass transition temperature B of the copolymer B is 10 to 50 ° C., and the expanded particles are 30 2. The expanded particle according to claim 1, comprising small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less in a cross-sectional photograph obtained by photographing an area of 11.9 mm 2 at a magnification.
In the copolymer A, the aromatic vinyl is a styrene monomer, the (meth) acrylic acid ester is a (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), the unsaturated dicarboxylic acid Are each selected from aliphatic unsaturated dicarboxylic acids having 2 to 6 carbon atoms, and the copolymer A is composed of units derived from three of the aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid. When the total is 100 parts by weight, 30 to 80 parts by weight of units derived from the aromatic vinyl, 8 to 35 parts by weight of units derived from the (meth) acrylic acid ester, and units derived from the unsaturated dicarboxylic acid 10 to 50 parts by weight,
In the copolymer B, the aromatic vinyl is a styrene monomer, the unsaturated dicarboxylic acid is an aliphatic unsaturated dicarboxylic acid having 2 to 6 carbon atoms, and the unsaturated dicarboxylic imide is a maleimide monomer, And the copolymer B is derived from the aromatic vinyl when the total of the units derived from the aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboxylic imide is 100 parts by weight. The expanded particle according to claim 7, comprising 20 to 80 parts by weight of a unit, 2 to 30 parts by weight of a unit derived from the unsaturated dicarboxylic acid, and 20 to 80 parts by weight of a unit derived from the unsaturated dicarboxylic imide.
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 di (meth) acrylate of bisphenol A and Selected from the propylene oxide adduct di (meth) acrylate of bisphenol A,
The (meth) acrylic acid 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 anhydrides thereof;
The unsaturated dicarboxylic imide is selected from maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N-naphthylmaleimide;
The expanded particles according to claim 7, wherein the copolymers A and B are contained in the base resin in a weight ratio of 70:30 to 95: 5.
It is a foam molded article composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid, and the foam molded article is composed of a plurality of the foamed particles. In the cross-sectional photograph in which the expanded particle is photographed in an area of 11.9 mm 2 at 30 times, the expanded particle is provided with small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less Molded body.
The foamed molded article according to claim 10, wherein the foamed particles have only one large bubble in one of them.
The aromatic vinyl is a styrene monomer, the (meth) acrylic acid ester is a (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), and the unsaturated dicarboxylic acid is 2 to 6 carbon atoms. Each selected from an aliphatic unsaturated dicarboxylic acid, and the copolymer is 100 parts by weight of the total of units derived from the aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, 30 to 80 parts by weight of units derived from the aromatic vinyl, 8 to 35 parts by weight of units derived from the (meth) acrylic acid ester, and 10 to 50 parts by weight of units derived from the unsaturated dicarboxylic acid The foamed molded product according to claim 10.
It is a foam molded article composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and the foam molded article is composed of a plurality of foam particles. In the cross-sectional photograph in which the expanded particle is photographed in an area of 11.9 mm 2 at 30 times, a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a large bubble having a bubble diameter of 300 μm or more and 2 mm or less are provided. The difference between the average bubble diameter of the bubbles and the average bubble diameter of the large bubbles is 1450 μm or more, and the thermal conductivity of the foamed molded body in which the foamed particles are composed of the fused product is 0.0350 W / m · K or less. The foamed molded product according to claim 10.
It is a foam molded article composed of a base resin containing a copolymer of aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid, and the foam molded article is composed of a plurality of foam particles. In the cross-sectional photograph in which the expanded particles are taken at an area of 11.9 mm 2 at 30 times, the expanded particles are provided with small bubbles having a bubble diameter of 50 μm or more and less than 300 μm and large bubbles having a bubble diameter of 300 μm or more and 2 mm or less. The difference between the average bubble diameter of the bubbles and the average bubble diameter of the large bubbles is 1000 μm or more and less than 1500 μm, and the foamed particle is a maximum of a foamed molded body composed of the fused body by a bending test of 1.0 MPa or more. The foaming molding of Claim 10 which gives a point stress.
Copolymer A of aromatic vinyl, (meth) acrylic acid ester, and unsaturated dicarboxylic acid, and copolymer B of aromatic vinyl, unsaturated dicarboxylic acid, and unsaturated dicarboxylic imide A foam molded body composed of a base resin, wherein the foam molded body is composed of a plurality of foam particles, and the glass transition temperature A of the copolymer A and the glass transition temperature B of the copolymer B In a cross-sectional photograph in which the difference is 10 to 50 ° C. and the foamed particles are taken in an area of 11.9 mm 2 at 30 times, a small bubble having a bubble diameter of 50 μm or more and less than 300 μm and a bubble diameter of 300 μm or more and 2 mm or less The foamed molded product according to claim 10, comprising the large bubbles.
In the copolymer A, the aromatic vinyl is a styrene monomer, the (meth) acrylic acid ester is a (meth) acrylic acid alkyl ester (the alkyl group has 1 to 5 carbon atoms), the unsaturated dicarboxylic acid Are each selected from aliphatic unsaturated dicarboxylic acids having 2 to 6 carbon atoms, and the copolymer A is composed of units derived from three of the aromatic vinyl, (meth) acrylic acid ester and unsaturated dicarboxylic acid. When the total is 100 parts by weight, 30 to 80 parts by weight of units derived from the aromatic vinyl, 8 to 35 parts by weight of units derived from the (meth) acrylic acid ester, and units derived from the unsaturated dicarboxylic acid 10 to 50 parts by weight,
In the copolymer B, the aromatic vinyl is a styrene monomer, the unsaturated dicarboxylic acid is an aliphatic unsaturated dicarboxylic acid having 2 to 6 carbon atoms, and the unsaturated dicarboxylic imide is a maleimide monomer, And the copolymer B is derived from the aromatic vinyl when the total of the units derived from the aromatic vinyl, unsaturated dicarboxylic acid and unsaturated dicarboxylic imide is 100 parts by weight. The foam molded article according to claim 15, comprising 20 to 80 parts by weight of units, 2 to 30 parts by weight of units derived from the unsaturated dicarboxylic acid, and 20 to 80 parts by weight of units derived from the unsaturated dicarboxylic imide. .
Expanded particles for producing the expanded molded article according to claim 13.
A fiber reinforced composite comprising the foam molded article according to claim 10 and a fiber reinforced plastic layer laminated and integrated on the surface of the foam molded article.
The fiber-reinforced composite according to claim 18, which is used for wind turbine blades, robot arms, and automobile parts.
An automotive part comprising the foamed molded product according to claim 10 or the fiber-reinforced composite according to claim 18.