JP6840630B2 - Vehicle seat member - Google Patents

Description

The present invention relates to a vehicle seat member.

Conventionally, as a seat used in an automobile or the like, a vehicle seat member in which a plurality of materials made of different materials are laminated has been used. As an example, there is a laminate in which a cushion layer made of a material having cushioning properties and a base material layer made of a lightweight material having higher strength and rigidity than the cushion layer are laminated.

As the material constituting the cushion layer, for example, soft polyurethane foam or the like is used, and it is configured so that the seating comfort and the hold feeling of the lumbar region when the passenger is seated are good.
On the other hand, as a material constituting the base material layer, for example, a rigid polyurethane foam or the like has been used. However, recently, thermoplastic resin foams such as styrene resin, ethylene resin, and propylene resin have been used as the material of the base material layer to supplement the strength and rigidity of the vehicle seat member and to supplement the strength and rigidity of the vehicle seat member. It is possible to reduce the weight of the product itself. By laminating the cushion layer made of the flexible polyurethane foam and the base material layer made of the thermoplastic resin foam in this way, it has become possible to obtain a vehicle seat member having complex characteristics.

As a method of forming such a vehicle seat member, there is a method using a molding die. Specifically, a member (thermoplastic resin foam) constituting the base material layer formed in advance is arranged in the molding space formed in the molding die, and the member is arranged in the molding space. There is a method of directly laminating the cushion layer on the surface of the base material layer by filling the material of the cushion layer (such as a liquid raw material for polyurethane foam) and foaming it to form the cushion layer.

However, since the cushion layer made of polyurethane foam and the foam of a thermoplastic resin such as propylene resin constituting the base material layer have poor adhesiveness, peeling between the polyurethane foam and the base material layer is suppressed. Is being considered. For example, in Patent Document 1, the foamable resin particles forming the contact region are softened by heating the contact region with the different material layer on the surface of the molded product at a temperature of 80% or more of the softening temperature of the molded product. A method for producing a laminated body has been proposed in which irregularities are formed in a contact region by expanding with the same, and a different material layer is formed so as to enter the concave portions of the irregularities.

Japanese Unexamined Patent Publication No. 2012-171104

However, in the laminate produced by the production method of Patent Document 1, the improvement in the adhesive strength between the polyurethane foam and the thermoplastic resin foam is not always sufficient, and it is difficult to reliably suppress the peeling between the layers. For example, when a laminate is used for a seat of an automobile or the like, peeling is likely to occur between the polyurethane foam and the base material layer, which reduces the seating comfort and hold feeling of the occupant, and the rubbing between the layers due to the peeling. There is a problem such as noise.

According to the present invention, in a vehicle seat member in which polyurethane foam is laminated and adhered to a core material made of a thermoplastic resin foam, the strength of the core material is strong even if the core material is made of a molded body having a complicated shape such as a thin wall portion. An object of the present invention is to provide a vehicle seat member having excellent rigidity and bondability between a core material and polyurethane foam.

According to the present invention, the following vehicle seat members are provided.
[1] In a method for manufacturing a vehicle seat member made of a core material made of a thermoplastic resin foam and a polyurethane foam laminated and adhered to the upper surface of the core material.
At least a part of the upper surface of the thermoplastic resin foam is formed of an upper surface of a foamed particle molded product composed of a group of foamed particles containing foamed particles having an adhesive-modified resin on the surface.
Foamed particles having the adhesive-modified resin on the surface are exposed on the upper surface of the foamed particle molded product.
The foamed particles are composed of a polyolefin resin (A2).
The adhesive modified resin is composed of a mixed resin of a polyolefin resin (A1) and a polystyrene resin and / or a polyester resin (B) .
The weight ratio of the polyolefin resin (A2) to the mixed resin is 97: 3 to 90:10.
The number of voids existing in the upper surface of the thermoplastic resin foam, is 200 30/10 cm ² or more pieces / 10 cm ² or less,
Polyurethane foam raw material liquid supplied to the upper surface of the thermoplastic resin foam, foamed, by solidifying, Ru obtain a vehicle seat member on the upper surface of the thermoplastic resin foam is a polyurethane foam formed by laminating adhesive A method for manufacturing a vehicle seat member.
[2] The weight ratio (A1: B) of the polyolefin resin (A1) to the polystyrene resin and / or the polyester resin (B) is 15:85 to 90:10. The method for manufacturing a vehicle seat member according to claim 1.
[3] The vehicle seat member according to claim 1 or 2, wherein the melting point (Ts) of the polyolefin resin (A1) is lower than the melting point (Tc) of the polyolefin resin (A2). Manufacturing method .
[4] The method for manufacturing a vehicle seat member according to any one of claims 1 to 3, wherein the polyolefin-based resin (A2) is a polypropylene-based resin.
[5] The production of a vehicle seat member according to any one of claims 1 to 4, wherein the adhesive strength between the foamed particle molded product and the polyurethane foam is 0.05 N / mm ^{2 or more.} Method .
[6] In a method for manufacturing a vehicle seat member made of a core material made of a thermoplastic resin foam and a polyurethane foam laminated and adhered to the upper surface of the core material.
The thermoplastic resin foam is composed of a foamed particle molded product in which foamed particles having an adhesive modified resin on the surface are fused to each other.
The foamed particles are composed of a polyolefin resin (A2).
The adhesive modified resin is composed of a mixed resin of a polyolefin resin (A1) and a polystyrene resin and / or a polyester resin (B) .
The weight ratio of the polyolefin resin (A2) to the mixed resin is 97: 3 to 90:10.
The number of voids existing in the upper surface of the thermoplastic resin foam, is 200 30/10 cm ² or more pieces / 10 cm ² or less,
Polyurethane foam raw material liquid supplied to the upper surface of the thermoplastic resin foam, foamed, by solidifying, Ru obtain a vehicle seat member on the upper surface of the thermoplastic resin foam is a polyurethane foam formed by laminating adhesive A method for manufacturing a vehicle seat member.

The vehicle seat member of the present invention comprises a core material made of a thermoplastic resin foam and a polyurethane foam laminated and adhered to the upper surface of the core material, and at least a part of the upper surface of the thermoplastic resin foam. Consists of an upper surface of a foamed particle molded body composed of a group of foamed particles containing foamed particles having an adhesive-modified resin on the surface, and foamed particles having an adhesive-modified resin on the upper surface of the foamed particle molded body. Is exposed, and the adhesive modified resin is composed of a specific mixed resin, so that the core material is made of a molded body having a complicated shape such as a thin wall portion. It is excellent in strength and rigidity, and also has excellent adhesion between the core material and the polyurethane foam, and peeling of the core material and the polyurethane foam is suppressed.

Hereinafter, the vehicle seat member of the present invention will be described in detail.
The vehicle seat member of the present invention is composed of a core material made of a thermoplastic resin foam (hereinafter, also simply referred to as a foam) and a polyurethane foam laminated and adhered to the upper surface of the core material. The vehicle seat member (hereinafter, also simply referred to as a seat member) has a cushioning property because the upper surface is covered with polyurethane foam, and the core material is made of a specific thermoplastic resin foam described later. As a result, it is lightweight and has excellent strength and rigidity. Further, since the foam has excellent adhesiveness, the core material and the polyurethane foam are firmly adhered to each other and are not easily peeled off.

The vehicle seat core material of the present invention is attached to the vehicle by arranging the thermoplastic resin foam and the polyurethane foam in this order from the bottom. Therefore, the upper surface of the thermoplastic resin foam means the surface of the thermoplastic resin foam on the side where the polyurethane foam is laminated and adhered.

In the present invention, foamed particle molding composed of a group of foamed particles containing foamed particles having an adhesive modified resin on the surface of at least a part of the upper surface (surface in contact with the polyurethane foam) of the thermoplastic resin foam. It is composed of the upper surface of the body. That is, the upper surface of the foamed particle molded body is the upper surface of the core material.
It should be noted that the entire upper surface of the foam does not have to be the upper surface of the foam particle molded product. For example, a part of the upper surface of the foam is formed of the upper surface of the foam particle molded product, and the upper surface of the foam is formed. The rest can also be made up of other foams.

In the present invention, foamed particles having an adhesive-modified resin on the surface are exposed on the upper surface of the foamed particle molded product. Specifically, the foamed particle molded product is a foamed particle molded product obtained by in-mold molding of foamed particles having an adhesive-modified resin on the surface, and the upper surface of the foamed particle molded product is the foamed material. Since it is on the upper surface of the surface, the foamed particles having the adhesive modifying resin on the surface can be exposed. As will be described later, since the foamed particles having the adhesively modified resin on the surface have excellent adhesiveness to the polyurethane foam, they are foamed by laminating both in a state where the foamed particles and the polyurethane foam are in contact with each other. The particle compact and the polyurethane foam can be strongly adhered (the core material and the polyurethane foam can be firmly adhered), and the peeling of the polyurethane foam can be suppressed.

As long as the initial object of the present invention can be achieved, it is not necessary that all of the foamed particle molded products are composed of foamed particles having an adhesive-modified resin on the surface, and the foamed product. A part (which may be formed in a plurality of places) of the upper surface of the above surface is composed of a foamed particle molded product in which foamed particles having an adhesive-modified resin on the surface are exposed, and the other part is composed of another foamed material. It is also possible to adopt another form. Further, the upper surface of the foam is formed of an upper surface of a foamed particle molded product formed by fusing foam particles having an adhesive-modified resin on the surface and foam particles having no adhesive-modified resin on the surface. You can also do it.

Further, as long as the foamed particles having the adhesively modified resin on the surface are exposed on the upper surface of the thermoplastic resin foam, a form in which a plurality of foams are laminated and bonded to form a core material is adopted. You can also do it.
Since the foam has an excellent balance between productivity and mechanical properties and the adhesiveness between the core material and the polyurethane foam, the foamed particles are fused with each other by the foamed particles having the adhesively modified resin on the surface. It is preferable to adopt a form composed of the foamed particle molded product.

The area of the polyolefin-based resin foam particles having the adhesive-modified resin on the surface with respect to the area of the core material in the top view of the core material from the viewpoint of the adhesiveness between the core material and the polyurethane foam and the suppression of the generation of rubbing noise. The ratio of the above is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, and particularly preferably 80% or more. The top view of the core material is a plan view when the upper surface of the core material is viewed in the height direction of the vehicle when the core material is attached to the vehicle.

The base resin of the thermoplastic resin foam constituting the core material is not particularly limited, but it is preferable to use a polyolefin resin from the viewpoint of the light weight and mechanical properties of the obtained core material. Polyethylene-based resins include polypropylene-based resins such as ethylene-propylene copolymer, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-propylene-butenter polymer, and homopolypropylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, and direct coating. Polyethylene-based resins such as chain low-density polyethylene, ultra-low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methylmethacrylate copolymer, and ionomer-based resin in which the molecules of ethylene-methacrylic acid copolymer are crosslinked with metal ions, polybutene, polypentene, etc. One or more of these can be exemplified.

The adhesive-modified resin in the present invention does not need to cover the entire foamed particles as long as the object and effect of the present invention are achieved, and the method for forming the adhesive-modified resin is particularly limited. is not it.
As a method of applying the adhesively modified resin to the surface of the foamed particles, for example, resin particles having a coating layer for forming the adhesively modified resin are formed by a coextrusion molding method described later, and the resin particles are formed. Is foamed to form foamed particles having an adhesive-modified resin on the surface (foamed particles coated with the adhesive-modified resin; hereinafter, also referred to as multilayer foamed particles), resin particles (before foaming), and foaming. After the particles are put into a mixer or the like and their surfaces are heated, the powder of the mixed resin for imparting the adhesive modification resin is put into the mixer or the like and the two are mixed to form resin particles or the like. Examples thereof include a method in which a mixed resin to be an adhesive modifying resin is attached to the surface of the foamed particles and / or melt-coated.

Among the above-mentioned forming methods, multi-layer foamed particles were produced by a coextrusion molding method from the viewpoint of being excellent in productivity and stably obtaining foamed particles having a homogeneous adhesive modification resin. A method in which the multilayer foamed particles are foamed particles having an adhesive modifying resin on the surface is preferable.
Hereinafter, the present invention will be described by taking as an example a foamed particle molded product in which multilayer foamed particles are fused to each other as an foamed particle molded product having exposed foamed particles having an adhesive modified resin on the surface. ..

Hereinafter, the multilayer foamed particles will be described.
The multilayer foamed particles have a multilayer structure composed of a core layer and a coating layer in a foamed state.

The coating layer is preferably a substantially non-foamed resin layer. If the coating layer of the foamed particles is foamed, the mechanical strength of the foamed particle molded product obtained by molding the foamed particles in the mold may be lowered. Here, the term "non-foaming" means not only those having no bubbles at all (including those in which the bubbles once formed at the time of preparing the foamed particles are destroyed and the bubbles disappear), but also a few extremely minute bubbles are present. Including what to do.
The coating layer of the multilayer foamed particles means an adhesive-modified resin in foamed particles having an adhesive-modified resin on the surface.

(Resin for coating layer)
Next, the mixed resin constituting the coating layer (adhesive modified resin) of the multilayer foamed particles will be described. The coating layer of the multilayer foamed particles is composed of a mixed resin of a polyolefin resin (A1) and a polystyrene resin and / or a polyester resin (B). That is, the mixed resin constituting the coating layer is (i) a mixed resin of a polyolefin resin and a polystyrene resin, (ii) a mixed resin of a polyolefin resin and a polyester resin, and (iii) a polyolefin resin and a polystyrene resin. It is either a resin or a mixed resin with a polyester resin.

The weight ratio (A1: B) of the polyolefin resin (A1) to the polystyrene resin and / or the polyester resin (B) is preferably 15:85 to 90:10. By setting the weight ratio of the mixed resin in the above range in the coating layer, the adhesive strength with the core layer becomes good, and the peeling between the core layer and the coating layer when the foamed particles are molded in the mold. Is less likely to occur, so that a good foamed particle molded product can be stably obtained. In addition, the adhesiveness with the polyurethane foam can be stably improved.
From this point of view, the weight ratio (A1: B) in the mixed resin constituting the coating layer is preferably 20:80 to 85:15, and more preferably 30:70 to 80:20.

The weight ratio (A1: B) means the weight ratio of the polyolefin resin (A1) and the polystyrene resin (B) in the case of (i), and in the case of (ii). , Means the weight ratio of the polyolefin resin (A1) and the polyester resin (B), and in the case of the above (iii), the polyolefin resin (A1) and the mixed resin of the polystyrene resin and the polyester resin ( It means the weight ratio with B).

(Polyolefin-based resin (A1) for the coating layer)
Examples of the polyolefin resin (A1) constituting the coating layer include a polyethylene resin, a polypropylene resin, and a mixture of two or more of them.
The polyethylene-based resin may be a polymer of ethylene monomer such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, or ethylene-vinyl acetate copolymer, or a copolymer of ethylene and comonomer. Examples thereof include those having an ethylene component of more than 50 mol%, and a mixture of two or more of them.
Examples of the polypropylene-based resin include a propylene monomer polymer, a propylene-ethylene copolymer, a propylene-butene copolymer, a propylene-ethylene-butene copolymer, and a mixture of two or more thereof. ..

From the viewpoint of the adhesiveness between the core layer and the coating layer, the polyolefin-based resin (A1) constituting the mixed resin of the coating layer is the same type of resin as the polyolefin-based resin (A2) constituting the core layer. Is preferable.

(Mixed resin of coating layer)
The mixed resin constituting the coating layer contains a polystyrene-based resin and / or a polyester-based resin. From the viewpoint of handleability at the time of manufacture, it is preferable to use either a polystyrene-based resin or a polyester-based resin.

Examples of the polystyrene-based resin constituting the coating layer include a polymer of a styrene-based monomer, a copolymer of a styrene-based monomer and another monomer, and a mixture of two or more of these. The structural unit derived from the styrene-based monomer contained in the copolymer is at least 50% by weight or more, preferably 60% by weight or more, and more preferably 80% by weight or more.

(Polystyrene resin for coating layer)
Specific examples of the polystyrene-based resin constituting the coating layer include polystyrene, rubber-modified polystyrene (impact-resistant polystyrene), styrene-acrylonitrile copolymer, styrene-acrylic acid copolymer, and styrene-methacrylic acid copolymer. , Styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer and the like can be exemplified. Among the polystyrene-based resins, polystyrene is preferable because it is excellent in moldability of foamed particles and adhesion to urethane foam.

(Polyester resin for coating layer)
Examples of the polyester-based resin constituting the coating layer include aliphatic polyesters and aromatic polyesters. The aliphatic polyester is a polyester containing an aliphatic polyvalent carboxylic acid component and an aliphatic polyhydric alcohol component, or a polyester containing an aliphatic hydroxycarboxylic acid component, and is, for example, polybutylene succinate, polybutylene adipate, or poly. Examples include lactic acid. The aromatic polyester is a polyester containing an aromatic polyvalent carboxylic acid component and a polyhydric alcohol component, and is, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polybutylene na. Examples include phthalate.

As the polyester-based resin used for the mixed resin constituting the coating layer of the present invention, it is preferable to use an amorphous polyester-based resin. The amorphous resin is preferable because it is excellent in the fusion property between the foamed particles at the time of in-mold molding. Further, when the amorphous polyester resin is used for manufacturing the vehicle seat member of the present invention, it becomes easy to obtain a seat member having a higher adhesive strength between the foamed particle molded product and the urethane foam.

In the present invention, the amorphous polyester resin is "when measuring the melting temperature after performing a certain heat treatment" based on JIS K7121 (1987) (the heating rate and the cooling rate in adjusting the state of the test piece are , All of which are set to 10 ° C./min.), Using a heat flow velocity differential scanning calorific value measuring device (hereinafter referred to as a DSC device), take a DSC curve at a heating rate of 10 ° C./min, and polyester of the DSC curve. It means a resin that does not show a heat absorption peak due to melting of the based resin. That is, a polyester-based resin having an endothermic peak calorific value of less than 5 J / g (including 0) is used as an amorphous polyester-based resin. The endothermic peak calorific value is preferably less than 2 J / g (including 0).

As the polyester-based resin used for the coating layer, an aliphatic polyester is preferable because it is excellent in moldability of foamed particles and adhesiveness to urethane foam, and a polylactic acid resin is preferable because it is excellent in mechanical properties such as flexural modulus. ..

As the polylactic acid resin, a resin containing 50 mol% or more of units derived from lactic acid can be used. The polylactic acid resin includes, for example, (a) a polymer of lactic acid, (b) a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid, (c) lactic acid, an aliphatic polyhydric alcohol, and an aliphatic polyvalent carboxylic acid. Copolymer of, (d) Copolymer of lactic acid and aliphatic polyvalent carboxylic acid, (e) Copolymer of lactic acid and aliphatic polyvalent alcohol (f) Mixture by any combination of these (a) to (e), etc. Is included. Specific examples of lactic acid include L-lactic acid, D-lactic acid, DL-lactic acid, or cyclic dimer thereof, L-lactide, D-lactide, DL-lactide, or a mixture thereof.

In the above (b), examples of other aliphatic hydroxycarboxylic acids include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxyheptanic acid and the like.
Further, in the above (c) and (e), examples of the aliphatic polyhydric alcohol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and deca. Examples thereof include methylene glycol, glycerin, trimethylolpropane, pentaerythritol and the like.
Further, in the above (c) and (d), examples of the aliphatic polyvalent carboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, succinic acid anhydride, adipic acid anhydride, trimesic acid, and propantricarboxylic acid. Examples thereof include acid, pyromellitic acid, and pyromellitic anhydride.

Further, it is preferable that the end of the molecular chain of the polylactic acid resin is blocked with one or more terminal blocking agents selected from carbodiimide compounds, epoxy compounds, isocyanate compounds and the like. By blocking the end of the molecular chain, it is possible to suppress a decrease in the molecular weight of the polylactic acid resin due to hydrolysis.

As the terminal blocking agent, for example, a carbodiimide compound, an oxazoline compound, an isocyanate compound, an epoxy compound and the like can be used. Of these, carbodiimide compounds are preferred. Specifically, aromatic monocarbodiimides such as bis (dipropylphenyl) carbodiimide (for example, Stabaxol 1-LF manufactured by Rheinchemy), aromatic polycarbodiimides (for example, Stabaxol P manufactured by Rheinchemy, Stabaxol P400 manufactured by Rheinchemy), etc. Examples thereof include aliphatic polycarbodiimides such as poly (4-4'-dicyclohexylmethanecarbodiimide) (for example, carbodilite LA-1 manufactured by Nisshinbo Chemical Co., Ltd.). These terminal blockers may be used alone or in combination of two or more. The content of the terminal blocking agent is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, per 100 parts by weight of the polylactic acid resin.

(Compatible agent)
The mixed resin constituting the coating layer may contain a compatibilizer for the polyolefin-based resin (A1) constituting the coating layer and the polystyrene-based resin and / or the polyester-based resin. By blending the compatibilizer, the adhesiveness between the foamed particle molded product and the polyurethane foam can be further improved. The blending amount of the compatibilizer is preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the mixed resin of the polyolefin resin and the polystyrene resin and / or the polyester resin of the coating layer. It is preferable, more preferably 7 to 13 parts by weight.

Examples of the compatibilizer include compounds that reduce the interfacial tension between the polyolefin-based resin constituting the coating layer and the polystyrene-based resin and / or the polyester-based resin, and enhance the adhesive strength between the two. Such products include, for example, ethylene-propylene rubber; ethylene-propylene-diene rubber; styrene-diene block copolymers, and hydrogen obtained by saturating at least a part of these double bonds by hydrogenation. Examples thereof include styrene-based thermoplastic elastomers such as additive block copolymers; polyolefin-based resins and maleic acid-modified products of these elastomers or rubbers; and graft polymers of polyolefin-based resins and these elastomers or rubbers using acrylic acid-based monomers. .. Further, in the present invention, the compatibilizer can be used alone or in combination of two or more.

Among the styrene-based thermoplastic elastomers, the styrene-diene block copolymer (a) or the hydrogenated block copolymer obtained by saturating at least a part of the double bonds in the styrene-diene block copolymer by hydrogenation. It is preferable to use (b).
Examples of the styrene-diene block copolymer (a) include styrene-1,3-butadiene block copolymer (SBS), styrene-1,3-pentadiene block copolymer, and styrene-isoprene block copolymer (Styrene-isoprene block copolymer). SIS), styrene- (2,3-dimethyl-1,3-butadiene) block copolymer, styrene- (3-methyl-1,3-octadien) block copolymer, styrene- (4-ethyl-1,3-octadien) A 3-hexadiene) block copolymer or the like can be exemplified. On the other hand, the hydrogenated block copolymer (b) includes styrene-butadiene-butylene-styrene (SBBS) in which the SBS double bond is partially reduced, and styrene-ethylene-in which the SBS double bond is completely reduced. Examples thereof include butylene-styrene copolymer (SEBS) and styrene-ethylene-propylene-styrene (SEPS) obtained by reducing the double bond of SIS.

Further, if necessary, additives such as a lubricant, a catalyst neutralizer, and an antioxidant can be added to the coating layer within a range that does not impair the object of the present invention. The amount of the additive added depends on the type, but is preferably 15 parts by weight or less, more preferably 10 parts by weight or less, still more preferably 5 parts by weight or less, and particularly preferably 5 parts by weight or less, based on 100 parts by weight of the mixed resin. It is preferably 1 part by weight or less.

(Polyolefin-based resin A2 in the core layer)
The polyolefin-based resin (A2) constituting the core layer of the multilayer foamed particles (foamed particles in the foamed particles having an adhesive-modified resin on the surface) is the same as the polyolefin-based resin (A1) constituting the coating layer. Can be used. Among them, polypropylene-based resins are preferable because they are excellent in balance between light weight and mechanical properties, and among them, propylene monomer polymers and ethylene-propylene copolymers are more preferable. The copolymer may be either a block copolymer or a random copolymer.

Further, another thermoplastic resin may be blended in the core layer of the multilayer foamed particles as long as the intended purpose is not impaired. Examples of the other thermoplastic resin include polystyrene-based resins such as polystyrene, impact-resistant polystyrene, and styrene-acrylonitrile copolymers, acrylic resins such as polymethylmethacrylate, and polyester-based resins such as polylactic acid and polyethylene terephthalate. Etc. can be exemplified.
Although it depends on the type of the other thermoplastic resin, 100 weight of the polyolefin resin constituting the core layer is considered from the viewpoint of achieving both the adhesiveness between the core material and the polyurethane foam and the mechanical properties of the foamed particle molded product. With respect to parts, 30 parts by weight or less is preferable, 20 parts by weight or less is more preferable, and 10 parts by weight or less is further preferable.

The melting point (Tc) of the polyolefin resin (A2) constituting the core layer is preferably 100 ° C. to 200 ° C., preferably 110 ° C. to 200 ° C., from the viewpoint of achieving both moldability and heat resistance during in-mold molding. It is more preferably 190 ° C., and even more preferably 130 ° C. to 170 ° C.

In the present invention, additives such as a catalyst neutralizing agent, a lubricant, a bubble nucleating agent, and a crystal nucleating agent can be added to the core layer. However, it is desirable that the amount is as small as possible without impairing the object of the present invention. The amount of the additive added depends on the type of additive and the purpose of use, but is preferably 15 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the polyolefin resin constituting the core layer. Yes, more preferably 5 parts by weight or less, and particularly preferably 1 part by weight or less.

In the present invention, when the polyolefin-based resin (A1) constituting the mixed resin of the coating layer is a crystalline resin, the coating layer (adhesion) is obtained from the viewpoint of obtaining foamed particles having good fusion property between the foamed particles. It is preferable that the melting point (Ts) of the polyolefin-based resin (A1) of the sex-modified resin) is lower than the melting point (Tc) of the polyolefin-based resin (A2) of the core layer (foamed particles). When the melting point of the coating layer is relatively low, the foamed particles can be more easily fused to each other during in-mold molding.

From the above viewpoint, the melting point difference (Tc—Ts) between the melting point of the polyolefin resin (A1) constituting the mixed resin of the coating layer and the melting point of the polyolefin resin (A2) constituting the core layer is 5 to 30 ° C. It is more preferable that the temperature is 10 to 25 ° C.

For the melting point of the polyolefin resin forming the core layer and the coating layer, the value obtained by the heat flux differential scanning calorimetry method (DSC method) based on JIS K 7122 (1987) is adopted. That is, 2 to 4 mg of the polyolefin resin used as a raw material is sampled, and the heat flux differential scanning calorimeter is used to measure the temperature from room temperature (10 to 40 ° C.) to 220 ° C. at a rate of 10 ° C./min again from 40 ° C. to 220 ° C. at 10 ° C. The second temperature rise is performed at a rate of / minute. The apex temperature of the DSC endothermic curve peak at the time of the second temperature rise obtained by such measurement is defined as the melting point. When there are two or more endothermic curve peaks, the peak temperature of the endothermic curve peak having the highest peak intensity is adopted as the melting point.

When the polyolefin-based resin (A1) constituting the mixed resin of the coating layer is made of a resin that does not exhibit a melting point, the bicut softening point of the polyolefin-based resin (A1) constituting the coating layer constitutes the core layer. It is preferably lower than the melting point of the polyolefin resin (A2).

In that case, the difference in softening temperature between the bicut softening point of the polyolefin-based resin (A1) constituting the mixed resin of the coating layer and the melting point of the polyolefin-based resin (A2) constituting the core layer is 5 to 30 ° C. More preferably, the temperature is 10 to 25 ° C.

In the present specification, the Vicat softening point is measured by the A50 method based on JIS K7206 (1999).

In the multilayer foamed particles, the resin forming the core layer (foamed particles) and the resin forming the coating layer (adhesive modified resin) are in a weight ratio of 99.5: 0.5 to 70: It is preferably 30, more preferably 99: 1 to 80:20, further preferably 98: 2 to 88:12, and particularly preferably 97: 3 to 90:10. When the weight ratio is within the above range, the foamed particles having an adhesively modified resin appropriately on the surface of the foamed particle molded product while maintaining the fusion strength between the foamed particles of the obtained foamed particle molded product. Since it can be exposed, it is possible to improve the adhesiveness between the core material and the polyurethane foam while maintaining the rigidity and strength of the core material.

(Manufacturing method of multilayer foamed particles)
The multilayer foamed particles composed of the core layer and the coating layer can be obtained by foaming the multilayer resin particles. The multilayer resin particles are described in methods known per se, for example, Japanese Patent Publication No. 41-16125, Japanese Patent Application Laid-Open No. 43-23858, Japanese Patent Application Laid-Open No. 44-29522, Japanese Patent Application Laid-Open No. 60-185816 and the like. It can be manufactured by the coextrusion method. Generally, a core layer forming extruder and a coating layer forming extruder are used, and these are connected to a coextrusion die. The core layer forming extruder heats and kneads the required resin component and the additive if necessary, and the coating layer forming extruder also heats the required resin component and the additive if necessary. , Knead. Each melt-kneaded product is merged in the die to form a multi-layer structure consisting of a columnar core layer and a coating layer covering the side surface of the core layer. Multilayer resin particles are produced by cutting so that the weight of the resin particles becomes a predetermined weight.

Examples of the shape of the multilayer resin particles include a columnar shape, a rugby ball shape, and a spherical shape.

The average weight of each of the multilayer resin particles is preferably 0.01 to 10.0 mg, particularly preferably 0.1 to 5.0 mg. The average weight of the foamed particles can be adjusted by adjusting the average weight of the resin particles for obtaining the foamed particles to the average weight of the foamed particles for the purpose. If the average weight of each foamed particle is too small, the foaming efficiency deteriorates. Therefore, the average weight of each foamed particle is preferably 0.01 to 10.0 mg, particularly 0.1 to 5.0 mg. It is preferable to have.

The multilayer foamed particles can be produced by foaming the multilayer resin particles. Specifically, first, the multilayer resin particles composed of the core layer and the coating layer are placed in a pressure-sensitive airtight container (for example, an autoclave) in an aqueous medium (usually, an aqueous medium to which a dispersant is added as needed). Disperse in water). Next, a required amount of foaming agent is press-fitted into the container under a predetermined temperature and pressure, and the resin particles are impregnated with the foaming agent. After that, the contents are discharged from the pressurized container together with the aqueous medium to a pressure range (under atmospheric pressure) lower than the internal pressure of the container to foam the core layer. In this way, the multilayer foamed particles can be produced (this method is hereinafter referred to as a dispersion medium release foaming method). At the time of this release, it is preferable to apply back pressure to the inside of the container to release the contents.

In the present invention, a physical foaming agent is used as the foaming agent, and the foaming agent is not particularly limited. For example, aliphatic hydrocarbons such as n-butane, i-butane, n-pentane, i-pentane, and n-hexane, and trichlorofluoromethane. , Organic physical foaming agents such as halogenated hydrocarbons such as dichlorofluoromethane, tetrachlorodifluoroethane, and dichloromethane, and inorganic physical foaming agents such as carbon dioxide, nitrogen, air, and water, alone or in admixture of two or more. Can be used. Among these foaming agents, it is preferable to use a foaming agent containing an inorganic physical foaming agent such as carbon dioxide, nitrogen, air, and water as a main component, and more preferably carbon dioxide is used.

The amount of the above-mentioned physical foaming agent added is appropriately selected according to the type of polyolefin resin, the type of foaming agent, the apparent density of the target foamed particles (foaming ratio), and the like. For example, when carbon dioxide is used as the physical foaming agent, it is preferably added in an amount of approximately 0.1 to 15 parts by weight, more preferably 0.5 to 12 parts by weight, based on 100 parts by weight of the polyolefin resin forming the core layer. , More preferably 1 to 10 parts by weight is used.

Dispersants include water-insoluble inorganic substances such as aluminum oxide, calcium tertiary phosphate, magnesium pyrophosphate, zinc oxide, kaolin, and mica, and water-soluble polymer-based protective colloids such as polyvinylpyrrolidone, polyvinyl alcohol, and methyl cellulose. And so on. Further, an anionic surfactant such as sodium dodecylbenzene sulfonate and sodium alkane sulfonate can be used.

Further, in order to obtain foamed particles having a particularly high foaming ratio, the foamed particles obtained by the above method are filled in a pressurable airtight container and pressure-treated with an inert gas such as air to inside the foamed particles. After performing an operation of increasing the gas pressure (internal pressure of the foamed particles), the foamed particles are taken out from the container and heated with steam or hot air to obtain foamed particles having a high foaming ratio (two steps). Foaming).

In the multilayer foamed particles, when 2 to 10 mg of the multilayer foamed particles are heated from 23 ° C. to 220 ° C. at a heating rate of 10 ° C./min by a heat flux differential scanning calorimetry method based on JIS K7122 (1987). The DSC curve (DSC curve of the first heating) obtained in the above is the endothermic peak A peculiar to the polyolefin resin (hereinafter, also simply referred to as “proprietary peak”) and one or more endothermic peaks on the high temperature side of the peculiar peak. It is preferable to have a peak B (hereinafter, also simply referred to as a “high temperature peak”). From the viewpoint of moldability and mechanical properties of the obtained foamed particle molded product, the amount of heat of fusion of the high temperature peak (hereinafter, also simply referred to as the amount of heat of the high temperature peak) is preferably 5 to 50 J / g, and is 7 to 50 J / g. More preferably, it is 30 J / g.

As a method for adjusting the high temperature peak in the dispersion medium release foaming method, for example, first, the multilayer resin particles dispersed in an aqueous medium are set to a temperature 20 ° C. lower than the melting point (Tc) of the resin, or the melting end temperature (Tce) of the resin. ), And hold at that temperature (Ta) for a sufficient time, preferably about 10 to 60 minutes. Then, the mixture is heated from a temperature 15 ° C. lower than the melting point (Tc) to a melting end temperature (Tce) + 10 ° C. (Tb), stopped at that temperature, and at that temperature for a further sufficient time, preferably about 10 to 60 minutes. After holding, it is preferable to release the resin particles from the closed container under low temperature to foam them.

The apparent density of the foamed particles (multilayer foamed particles) having the adhesive-modified resin on the surface ^{is preferably 10 to 300 kg / m 3} , more preferably 15 to 150 kg / m ³ , and further preferably 20 to 100 kg. It is / m ³ , and particularly preferably 30 to 80 kg / m ³ . By setting the apparent density in the above range, the balance between the light weight of the obtained foamed particle molded product and the mechanical properties can be improved. Further, when the raw material for forming polyurethane foam is supplied to the upper surface of the foam in the molding die and foamed, the deformation of the upper surface of the foam due to the pressure during foaming of the raw material can be stably prevented. At the same time, the pressure allows the polyurethane foam and the foamed particle molded product to be more firmly adhered to each other.

The apparent density of the foamed particles is measured as follows. First, a group of foamed particles having a weight of W (g) is submerged in a measuring cylinder filled with water using a wire mesh or the like, and the volume V (L) of the group of foamed particles is obtained from the amount of increase in water level. Then, by unit conversion a value determined by dividing the weight of the expanded particles by the volume of the foamed particles (W / V) in kg / m ^3, the apparent density of the expanded beads is determined.

The average cell diameter of the foamed particles of the present invention is preferably 50 to 500 μm from the viewpoint of secondary foamability of the foamed particles, mold transferability, and the like. Further, the average cell diameter is more preferably 60 μm or more, further preferably 70 μm or more, and particularly preferably 80 μm or more. On the other hand, the upper limit thereof is more preferably 300 μm or less, further preferably 250 μm or less, and particularly preferably 200 μm or less from the viewpoint of strength against compressive stress of the obtained foam and appearance smoothness.

To measure the average cell diameter of the foamed particles, the cross section of the foamed particles bisected is enlarged under a microscope so that the entire cross section is included, and the cross section is photographed. A straight line is drawn on the photograph taken so that the cross section is roughly bisected, and the value obtained by dividing the length of the straight line by the number of all bubbles in contact with the straight line is taken as the average cell diameter of one foamed particle. The same measurement is performed on 20 foamed particles, and the arithmetic mean value thereof is taken as the average cell diameter of the foamed particles.

The closed cell ratio of the foamed particles used in the present invention is preferably 80% or more. When the closed cell ratio is in the above range, it is possible to obtain a foamed particle molded product having excellent secondary foamability of the foamed particles and excellent mechanical properties such as bending elastic modulus. From this point of view, the closed cell ratio of the foamed particles is more preferably 85% or more, still more preferably 90% or more.

The closed cell ratio of the foamed particles is measured as follows.
The foamed particles are cured by leaving them in a thermostatic chamber at atmospheric pressure, relative humidity of 50%, and 23 ° C. for 10 days. Next, in the same homeothermic chamber, the foamed particles after curing having a bulk volume of about 20 cm3 are used as a measurement sample, and the apparent volume Va is accurately measured by the submersion method as described below. After the measurement sample having the apparent volume Va is sufficiently dried, the measurement is performed by the air comparison hydrometer 930 manufactured by Toshiba Beckman Co., Ltd. according to the procedure C described in ASTM-D2856-70. Measure the true volume Vx of the sample for use. Then, based on these volumes Va and Vx, the closed cell ratio is calculated by the following equation (1), and the average value of N = 5 is used as the closed cell ratio of the foamed particles.
Closed cell ratio (%) = (Vx-W / ρ) x 100 / (Va-W / ρ) ... (1)
However,
Vx: The true volume of the foamed particles measured by the above method, that is, the sum of the volume of the resin constituting the foamed particles and the total volume of the closed cells in the foamed particles (cm ³ ).
^{Va: The apparent volume of the foamed particles (cm 3} ) measured from the rise in water level when the foamed particles are submerged in a graduated cylinder containing water.
W: Weight (g) of sample for measuring foamed particles,
ρ: Density of resin constituting foamed particles (g / cm ³ ),
Is.

(Manufacturing method of foamed particle molded product)
The foamed particle molded product can be produced by an in-mold molding method known per se.
For example, using a pair of molds for in-mold molding of conventional foamed particles, the foamed particles are filled in the mold cavity under atmospheric pressure or reduced pressure, and the mold is closed to reduce the volume of the mold cavity by 5 to 70%. A method by a vacuum molding method (for example, Japanese Patent Application Laid-Open No. 46-38359) in which the foamed particles are heated and fused by supplying a heat medium such as steam into the mold to heat and fuse the foamed particles. Is pre-pressurized with a pressurized gas such as air to increase the pressure inside the foamed particles to increase the secondary foamability of the foamed particles and maintain the secondary foaming property while foaming under atmospheric pressure or reduced pressure. By a pressure molding method (for example, Japanese Patent Application Laid-Open No. 51-22951) in which particles are filled in a mold cavity, the mold is closed, and then a heating medium such as steam is supplied into the mold to heat-fuse the foamed particles. Can be molded. Further, after filling the cavity pressurized to the atmospheric pressure or more by the compressed gas with the foamed particles pressurized to the pressure or more, a heating medium such as steam is supplied to the cavity to heat and fuse the foamed particles. It can also be molded by a filling molding method (for example, Japanese Patent Publication No. 4-46217). In addition, foamed particles having high secondary foamability are filled in a pair of molded cavities under atmospheric pressure or reduced pressure, and then a heating medium such as steam is supplied to heat the foamed particles. It can also be molded by an atmospheric pressure filling molding method (for example, Japanese Patent Publication No. 6-49795) or a method in which the above methods are combined (for example, Japanese Patent Publication No. 6-22919).

The apparent density of the thermoplastic resin foam (foamed particle molded product) of the present invention can be arbitrarily set depending on the intended purpose, but from the viewpoint of light weight and mechanical properties, it is preferably in the range of ^{15 to 200 kg / m 3.} , More preferably 20 to 100 kg / m ³ , and particularly preferably 30 to 80 kg / m ³ .
The apparent density of the foamed particle molded product is calculated by dividing the weight (kg) of the test piece cut out from the molded product by the volume (m ^{3) obtained from the external dimensions of the test piece.}

Further, the thermoplastic resin foam (foamed particle molded product) of the present invention preferably has a void on the upper surface. Due to the presence of voids on the upper surface of the foam, when the raw material for forming polyurethane foam is supplied to the upper surface of the foam and foamed in the molding die, a part of the polyurethane foam is formed due to the pressure during foaming of the raw material. Enters the void and solidifies. Thereby, the adhesiveness between the foam and the polyurethane foam can be further enhanced.
From the above viewpoint, the number of voids existing on the upper surface of the foam ^{is preferably about 30 pieces / 10 cm 2} or more, and more preferably 50 pieces / 10 cm ² or more. Further, the upper limit of the number of voids existing on the upper surface ^{is preferably about 200 pieces / 10 cm 2} and more preferably 150 pieces / 10 cm ^{2 although} it depends on the shape of the foam and the like.

(Manufacturing method of vehicle seat members)
The vehicle seat member of the present invention is composed of a foamed particle molded body in which at least a part of the upper surface thereof is composed of a foamed particle group containing foamed particles having an adhesive-modified resin on the surface, and the foamed particle molded body. Polyurethane foam is laminated and adhered to the upper surface of a thermoplastic resin foam in which foam particles having an adhesive-modified resin on the surface are exposed on the upper surface. The polyurethane foam is laminated on one surface of the foam, whether it is laminated in a form that completely covers the surface of the foam or in a form in which a part of the surface of the foam is exposed. You may.

(Polyurethane foam)
The vehicle seat member of the present invention can be obtained by laminating and adhering polyurethane foam to the upper surface of the core material. That is, by foaming and solidifying the liquid polyurethane foam raw material on the upper surface of the foam, the polyurethane foam is laminated and adhered to the upper surface of the foam to obtain a vehicle seat member.
For example, in a molding mold for laminating polyurethane foam, a liquid raw material for polyurethane foam is supplied to the upper surface of the core material, and the raw material is foamed and solidified in the molding mold to form polyurethane foam and at the same time. It is possible to obtain a vehicle seat member in which a core material and a polyurethane foam are laminated and adhered.

As the liquid raw material for polyurethane foam used for producing polyurethane foam, known materials can be appropriately used, and polyurethane and various foaming agents can be included. Further, the amount of the raw material for the liquid polyurethane foam can be appropriately set according to the desired density of the polyurethane foam.

From the viewpoint of adhesiveness, the adhesive strength between the foamed particle molded product and the polyurethane foam ^{is preferably 0.05 N / mm 2} or more. The adhesive strength can be measured by a peeling test according to the method of JIS K 6850 (1999) described later. The adhesive strength is measured on the upper surface portion of the core material in which the foamed particles having the adhesive modifying resin on the surface are exposed, and the adhesive strength is calculated at five or more locations randomly selected from the upper surface portion. The average value shall be adopted as the adhesive strength between the core material and the polyurethane foam.

Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.

The physical properties and evaluation of the foamed particles were measured by the following methods. The apparent density, closed cell ratio, and average cell diameter of the foamed particles were measured by the methods described in the specification.

"Heat absorption of high temperature peak of foamed particles"
The heat absorption amount of the high temperature peak of the foamed particles was determined by measuring by the method described in JIS K7121 (1987) "When measuring the melting temperature after performing a certain heat treatment". .. DSCQ1000 manufactured by TA Instruments Co., Ltd. was used as a measuring device.

(Measurement and evaluation method of physical properties of thermoplastic resin foam)
The physical properties and evaluation of the foamed particle molded product (thermoplastic resin foam) obtained by molding the obtained foamed particles in the mold were measured by the following methods.
"Apparent density of foamed particle molded product"
The apparent density (g / L) of the foamed particle molded body was determined from the external dimensions of the foamed particle molded body left to stand for 24 hours or more in an environment of a temperature of 23 ° C. and a relative humidity of 50%. Next, the weight (g) of the foamed particle molded product was precisely weighed. It was determined by dividing the weight of the foamed particle molded product by the apparent volume and converting it into units.

"Fusion rate of foamed particle molded product"
The fusion rate of the foamed particle molded product was determined based on the ratio (fusion rate) of the number of foamed particles whose material was broken among the foamed particles exposed on the fracture surface when the foamed particle molded product was broken. Specifically, the foamed particle molded product was cut with a cutter knife by about 10 mm in the thickness direction of the foamed particle molded product, and then the foamed particle molded product was broken from the cut portion. Next, the number of foamed particles (n) present in the fracture surface and the number of foamed particles (b) whose material was destroyed were measured, and the ratio (b / n) of (b) and (n) was expressed as a percentage. The fusion rate (%) was used.

"Bending elastic modulus of foamed particle molded product"
The flexural modulus was measured according to the measuring method described in JIS K 7221-1 (2006). First, a test piece having a thickness of 20 mm, a width of 25 mm, and a length of 120 mm was cut out from the foamed particle molded body by cutting the skins on both sides thereof. The prepared test piece was left in a constant temperature room at room temperature of 23 ° C. and humidity of 50% for 24 hours or more, and then the test piece was placed so that the skin-cut surface touched the support, and the distance between fulcrums was 100 mm and the indenter was used. The flexural modulus was measured with an Autograph AGS-10kNX (manufactured by Shimadzu Corporation) tester under the conditions of a radius of R15.0 mm, a radius of support R25.0 mm, a test speed of 10 mm / min, a room temperature of 23 ° C., and a humidity of 50%. .. The average value of the calculated values (5 points or more) was adopted as the flexural modulus of the foamed particle molded product.

"Number of voids present on the upper surface of the foamed particle molded product"
The number of voids present on the upper surface of the molded product was measured as follows.
First, on the surface of the obtained molded product (the surface on the 250 mm × 200 mm side), at randomly selected locations (however, continuous surfaces without steam holes, filling devices, mold release pins, and other mold structures). A 100 mm x 10 mm border was drawn. Next, in that range, the number of voids having a width exceeding 0.5 mm in the plane direction (gap between foamed particles) and voids having a depth exceeding 0.5 mm in the thickness direction were counted. At this time, when one void satisfies the above two conditions at the same time, it is counted as one void. From the measured ^{voids, the number of voids per 10 cm 2} was calculated, and this was taken as the number of voids existing on the upper surface of the foamed particle molded product.

Examples 1-6
<Manufacturing of multilayer foam particles>
(Manufacturing of multilayer resin particles)
An extruder with an inner diameter of 65 mm for forming a core layer and an extruder for forming a coating layer (adhesive modified resin) with an inner diameter of 30 mm, and an extruder equipped with a die capable of coextruding a large number of multilayer strands on the outlet side. Was used. A circular coextrusion die having a hole with a diameter of 2 mm was used.

Ethylene-propylene random copolymer shown as "PP1" in Table 1 as a polyolefin resin (A2) in a core layer forming extruder [Ethylene content: 2.8%, melting point: 143 ° C, MFR (230 ° C / 2.). 16 kgf): 5.1 g / 10 min] was supplied, and the mixed resins shown in Table 1 were supplied to the extruder for forming a coating layer, and each was melt-kneaded.
“PP2” in Table 1 is an ethylene-propylene random copolymer [ethylene content 3.5% by weight, melting point: 125 ° C., MFR (230 ° C./2.16 kgf): 7 (g / 10 min)]. “PLA” in Table 1 is an amorphous polylactic acid resin manufactured by Nature Works Co., Ltd. [Product name: 4060D, heat absorption 0J / g, Vicat softening point: 58 ° C., D-form content 11.8% by weight, MFR ( 190 ° C./2.16 kgf): 4.4 (g / 10 min)], 1.5 phr of bis (dipropylphenyl) carbodiimide [trade name: Stavacol 1-LF] manufactured by Rheinchemy Co., Ltd. was added as a terminal sealant. The resin shown as "PS" in Table 1 is a polystyrene resin manufactured by PS Japan Co., Ltd. [GPPS, grade name: HF77, glass transition temperature: 97 ° C., MFR (200 ° C./5 kgf): 7. 5 (g / 10min)], and the mixed resin is a mixture of "PP2", "PLA", and "PS" in the weight ratio shown in Table 1. The mixed resin contains a styrene elastomer [SBS, trade name: TR2250, styrene / rubber = 52/48, MFR (190 ° C./2.16 kgf): 0.7 (SBS, trade name: TR2250, styrene / rubber = 52/48), as a compatibilizer, manufactured by JSR Corporation. g / 10 min)] was added in an amount of 11 parts by weight based on 100 parts by weight of the total amount of the resins constituting the mixed resin (however, the weight of the compatibilizer was not included).

The polyolefin resin (A2) melt-kneaded in the extruder and the mixed resin are supplied to a co-extrusion die so that the weight ratio of the core layer / coating layer is 95/5, laminated in the die, and extruded. A laminated body having a circular cross section in which the outer peripheral surface of the core layer is covered with a coating layer is extruded from the pores of the mouthpiece attached to the tip of the machine, the extruded laminated body is water-cooled, and then the weight per one is perpetizer. It was cut to about 1.5 mg and dried to obtain multilayer resin particles.
In addition, zinc borate was supplied to the polyolefin resin of the core layer as a bubble adjusting agent so that the content thereof was 1000 ppm by weight.

<Manufacturing of multilayer foam particles>
Next, the multilayer resin particles were used to prepare multilayer foamed particles.
First, 1 kg of the multilayer resin particles obtained as described above is put into a 5 L closed container equipped with a stirrer together with 3 L of water as a dispersion medium, and further, with respect to 100 parts by weight of the multilayer resin particles in the dispersion medium. As a dispersant, 0.3 parts by weight of kaolin, 0.004 parts by weight of a surfactant (trade name: Neogen S-20F, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., sodium alkylbenzene sulfonate) as an active ingredient, a foaming agent As shown in Table 1, the amount of carbon dioxide shown in Table 1 was added in the state of dry ice.
Next, the temperature inside the container was raised to a temperature 5 ° C. lower than the foaming temperature shown in Table 1 while stirring, and the temperature was maintained at that temperature for 15 minutes. Then, the temperature was raised to the foaming temperature of each example, and the temperature was maintained for 15 minutes.
Then, the contents were released under atmospheric pressure while applying back pressure to the inside of the container with carbon dioxide to obtain multilayer foamed particles having an apparent density shown in Table 1.

<Manufacturing of foamed particle molded product>
A foamed particle molded product was produced using the obtained multilayer foamed particles. First, compressed air is press-fitted into a pressure vessel containing the multi-layer foamed particles to obtain multi-layer foamed particles to which an internal particle pressure of 0.10 MPa (G) (where (G) means a gauge pressure) is applied. It was. Next, the multilayer foamed particles are filled in a pair of molds for flat plate molding having a length of 200 mm, a width of 250 mm, and a thickness of 50 mm, and in-mold molding is performed by pressure molding by steam heating to perform plate-shaped foamed particles. A molded product was obtained. At this time, steam is supplied for 5 seconds with the drain valves of the molds on both sides open to perform preheating (exhaust process), and then the pressure is 0.04 MPa (G) lower than the main heating pressure. After heating, one-sided heating was performed from the opposite direction at a pressure 0.02 MPa (G) lower than the main heating pressure, and then main heating was performed at a molding steam pressure of 0.22 MPa (G).
After the heating is completed, the pressure inside the mold is released, the molded product is water-cooled until the pressure on the surface inside the mold due to the foaming force of the molded product drops to 0.04 MPa (G), and then the mold is opened and the molded product is opened. Was taken out of the mold. The obtained molded product was cured in an oven at 80 ° C. for 12 hours, and then the molded product was slowly cooled to obtain a foamed particle molded product. The physical characteristics of the obtained molded product are shown in Table 1.

<Making a laminate of foamed particle molded product and polyurethane foam>
A laminate of a foamed particle molded body and a polyurethane foam was produced according to JIS K 6850 (1999) "Adhesive-Tensile Shear Adhesive Strength Test Method for Rigid Adhesive Material".
Two test pieces having a thickness of 5 mm were cut out from the foamed particle molded product while leaving the skin of the molded product. Apply the polyurethane foam forming raw material solution (manufactured by Henkel Japan, "Loctite Green Foam") to the skin surface of one of the test pieces, and make the obtained polyurethane foam 5 mm thick and ^{65 kg / m 3 in density.} One of the test pieces was placed and fixed so that the skin surface was in contact with the raw material for forming polyurethane foam. Next, the raw material liquid for forming polyurethane foam was foamed and solidified in an open system for 48 hours at room temperature, and then excess polyurethane foam was removed to obtain a laminate having an adhesive surface size of 25 mm × 12.5 mm. .. In the produced laminate, the foamed particle molded product having a thickness of 5 mm corresponds to the adhesive, and the polyurethane foam having a thickness of 5 mm corresponds to the adhesive.

"Adhesion between polyurethane foam and foamed particle molded product"
A peeling test was conducted according to the method of JIS K 6850 (1999), and the adhesiveness was evaluated according to the following criteria. In addition, the adhesive strength between the polyurethane foam and the foamed particle molded product was measured.
A: The foamed particle molded product or polyurethane foam is destroyed and the polyurethane foam and the foamed particle molded product are separated. X: The foamed particle molded product and the urethane foam are separated from each other.

Comparative Examples 1 and 2
Resin particles, foamed particles, and foamed particle molded products were obtained in the same manner as in Example 1 except that resin particles having only a core layer were produced without forming a coating layer. Further, using the obtained foamed particle molded product, a laminated body of the foamed particle molded product and the polyurethane foam was obtained in the same manner as in Example 1. Table 1 shows these physical characteristics.

Claims (6)

In a method for manufacturing a vehicle seat member composed of a core material made of a thermoplastic resin foam and a polyurethane foam laminated and adhered to the upper surface of the core material.
At least a part of the upper surface of the thermoplastic resin foam is formed of an upper surface of a foamed particle molded product composed of a group of foamed particles containing foamed particles having an adhesive-modified resin on the surface.
Foamed particles having the adhesive-modified resin on the surface are exposed on the upper surface of the foamed particle molded product.
The foamed particles are composed of a polyolefin resin (A2).
The adhesive modified resin is composed of a mixed resin of a polyolefin resin (A1) and a polystyrene resin and / or a polyester resin (B) .
The weight ratio of the polyolefin resin (A2) to the mixed resin is 97: 3 to 90:10.
The number of voids existing in the upper surface of the thermoplastic resin foam, is 200 30/10 cm ² or more pieces / 10 cm ² or less,
Polyurethane foam raw material liquid supplied to the upper surface of the thermoplastic resin foam, foamed, by solidifying, Ru obtain a vehicle seat member on the upper surface of the thermoplastic resin foam is a polyurethane foam formed by laminating adhesive A method for manufacturing a vehicle seat member.
Claim 1 is characterized in that the weight ratio (A1: B) of the polyolefin resin (A1) to the polystyrene resin and / or the polyester resin (B) is 15:85 to 90:10. A method for manufacturing a vehicle seat member according to the above.
The method for manufacturing a vehicle seat member according to claim 1 or 2, wherein the melting point (Ts) of the polyolefin resin (A1) is lower than the melting point (Tc) of the polyolefin resin (A2). ..
The method for manufacturing a vehicle seat member according to any one of claims 1 to 3, wherein the polyolefin-based resin (A2) is a polypropylene-based resin.
The method for manufacturing a vehicle seat member according to any one of claims 1 to 4, wherein the adhesive strength between the foamed particle molded product and the polyurethane foam is 0.05 N / mm ² or more.
In a method for manufacturing a vehicle seat member composed of a core material made of a thermoplastic resin foam and a polyurethane foam laminated and adhered to the upper surface of the core material.
The thermoplastic resin foam is composed of a foamed particle molded product in which foamed particles having an adhesive modified resin on the surface are fused to each other.
The foamed particles are composed of a polyolefin resin (A2).
The adhesive modified resin is composed of a mixed resin of a polyolefin resin (A1) and a polystyrene resin and / or a polyester resin (B) .
The weight ratio of the polyolefin resin (A2) to the mixed resin is 97: 3 to 90:10.
The number of voids existing in the upper surface of the thermoplastic resin foam, is 200 30/10 cm ² or more pieces / 10 cm ² or less,

Polyurethane foam raw material liquid supplied to the upper surface of the thermoplastic resin foam, foamed, by solidifying, Ru obtain a vehicle seat member on the upper surface of the thermoplastic resin foam is a polyurethane foam formed by laminating adhesive A method for manufacturing a vehicle seat member.