阅读说明：本技术 表皮、表皮的制造方法及层叠体 (Skin, method for producing skin, and laminate ) 是由 西村翔太 于 2019-03-18 设计创作，主要内容包括：本发明的目的在于提供能够良好地抑制在加衬了发泡聚氨酯成型体而使用的情况下的热收缩的表皮。本发明的表皮的特征在于,其为具有包含氯乙烯树脂和增塑剂的氯乙烯树脂成型片(X)和发泡氯乙烯树脂成型片(Y)的表皮,上述氯乙烯树脂成型片(X)中的上述增塑剂的含量相对于100质量份的上述氯乙烯树脂为50质量份以上,上述发泡氯乙烯树脂成型片(Y)配置在上述氯乙烯树脂成型片(X)的厚度方向的一侧。(The purpose of the present invention is to provide a skin that can satisfactorily suppress heat shrinkage when used with a foamed polyurethane molded article lined. The skin of the present invention is characterized by comprising a molded sheet (X) of vinyl chloride resin containing a vinyl chloride resin and a plasticizer, and a molded sheet (Y) of foamed vinyl chloride resin, wherein the content of the plasticizer in the molded sheet (X) of vinyl chloride resin is 50 parts by mass or more per 100 parts by mass of the vinyl chloride resin, and the molded sheet (Y) of foamed vinyl chloride resin is disposed on one side in the thickness direction of the molded sheet (X) of vinyl chloride resin.)

1. A skin having a molded sheet X of vinyl chloride resin and a molded sheet Y of foamed vinyl chloride resin,

the vinyl chloride resin molding sheet X comprises a vinyl chloride resin and a plasticizer,

the content of the plasticizer in the vinyl chloride resin molding sheet X is 50 parts by mass or more per 100 parts by mass of the vinyl chloride resin,

the foamed vinyl chloride resin molding sheet Y is disposed on one side in the thickness direction of the vinyl chloride resin molding sheet X.

2. The skin according to claim 1, wherein the thickness of the molded sheet Y of foamed vinyl chloride resin is 1.5mm or more.

3. The skin according to claim 1 or 2, wherein the foamed vinyl chloride resin molded sheet Y contains an acrylic polymer.

4. The skin of claim 3, wherein the acrylic polymer comprises a copolymer of alkyl methacrylate and alkyl acrylate.

5. The skin according to any one of claims 1 to 4, which is used for a skin of an automobile interior part.

6. A method for manufacturing a skin having a molded sheet X of vinyl chloride resin and a molded sheet Y of foamed vinyl chloride resin, comprising the steps of:

a first step of forming a vinyl chloride resin molded sheet X using a vinyl chloride resin composition A containing a vinyl chloride resin and a plasticizer; and

a 2 nd step of forming a foamed vinyl chloride resin molded sheet Y on one side in the thickness direction of the vinyl chloride resin molded sheet X using a foamable vinyl chloride resin composition B,

the content of the plasticizer in the vinyl chloride resin composition a is 50 parts by mass or more with respect to 100 parts by mass of the vinyl chloride resin.

7. The method for producing a skin according to claim 6, wherein the foamable vinyl chloride resin composition B contains a thermal decomposition type foaming agent.

8. The method for manufacturing a skin according to claim 7, wherein the thermal decomposition type foaming agent contains an azo compound.

9. The method for producing a skin according to claim 7 or 8, wherein the volume average particle diameter of the thermal decomposition type foaming agent is 10 μm or less.

10. A laminate comprising a foamed polyurethane molded body and the skin according to any one of claims 1 to 5,

the foamed vinyl chloride resin molded sheet Y is disposed between the foamed polyurethane molded body and the vinyl chloride resin molded sheet X.

Technical Field

The present invention relates to a skin, a method for producing a skin, and a laminate.

Background

Vinyl chloride resins are generally used in various applications because of their excellent properties such as cold resistance, heat resistance, and oil resistance.

Specifically, for example, in the formation of automobile interior parts such as automobile instrument panels, automobile interior materials such as laminates in which a foam such as foamed polyurethane is lined on a skin formed from a molded vinyl chloride resin product obtained by molding a vinyl chloride resin composition into a sheet (hereinafter, sometimes referred to as a "molded vinyl chloride resin sheet") or a skin formed from a molded vinyl chloride resin sheet have been conventionally used.

As a material for a vinyl chloride resin molded sheet, a vinyl chloride resin composition containing a vinyl chloride resin and a plasticizer is used (for example, see patent documents 1 and 2).

Disclosure of Invention

Problems to be solved by the invention

Here, as in the conventional technique described above, a plasticizer is generally used in order to improve the flexibility and the like of the molded sheet of vinyl chloride resin. However, when a skin formed of a molded sheet of vinyl chloride resin containing a plasticizer is used to line a foam such as a foamed polyurethane molded article, the skin shrinks under high temperature conditions, which results in a problem that the design of the automobile interior material is impaired. Therefore, it is required to suppress the heat shrinkage of the skin when used as a lining for a foamed polyurethane molded article.

Accordingly, an object of the present invention is to provide a skin that can satisfactorily suppress heat shrinkage when used as a lining for a foamed polyurethane molded article.

Further, the present invention aims to provide a laminate having the skin and capable of satisfactorily suppressing thermal shrinkage.

Means for solving the problems

The present inventors have conducted intensive studies with a view to solving the above problems. The present inventors have also found that if a skin is formed by disposing a molded sheet of a foamed vinyl chloride resin on one side in the thickness direction of a molded sheet of a vinyl chloride resin containing a plasticizer, heat shrinkage of the skin can be favorably suppressed when the skin is used while lining a foamed polyurethane molded body, and have completed the present invention.

That is, the present invention has an object to advantageously solve the above-mentioned problems, and a skin of the present invention is characterized by having a molded sheet (X) of vinyl chloride resin containing a vinyl chloride resin and a plasticizer and a molded sheet (Y) of foamed vinyl chloride resin, wherein the content of the plasticizer in the molded sheet (X) of vinyl chloride resin is 50 parts by mass or more with respect to 100 parts by mass of the vinyl chloride resin, and the molded sheet (Y) of foamed vinyl chloride resin is disposed on one side in the thickness direction of the molded sheet (X) of vinyl chloride resin. In this manner, if the skin is formed by disposing the foamed vinyl chloride resin molded sheet on one side in the thickness direction of the vinyl chloride resin molded sheet containing the plasticizer, the thermal shrinkage when the foamed polyurethane molded body is used as a lining can be favorably suppressed.

In the skin of the present invention, the thickness of the molded sheet (Y) of the foamed vinyl chloride resin is preferably 1.5mm or more. When the thickness of the molded sheet (Y) of a foamed vinyl chloride resin is not less than the above-mentioned predetermined value, the thermal shrinkage in the case of using the foamed polyurethane molded article as a lining can be further favorably suppressed.

In the present invention, the thickness of the molded sheet (Y) of the foamed vinyl chloride resin can be measured using an optical microscope.

In the skin of the present invention, it is preferable that the foamed vinyl chloride resin molded sheet (Y) contains an acrylic polymer. When the foamed vinyl chloride resin molded sheet (Y) contains an acrylic polymer, the hardness of the skin can be reduced.

In the skin of the present invention, the acrylic polymer preferably contains a copolymer of an alkyl methacrylate and an alkyl acrylate. If the acrylic polymer contains a copolymer of an alkyl methacrylate and an alkyl acrylate, the hardness of the skin can be further reduced.

Furthermore, the skin of the present invention is preferably used for automotive interior parts. When the skin of the present invention is used as a skin of an automobile interior part, thermal shrinkage can be favorably suppressed when the skin is used while lining a foamed polyurethane molded article, and deterioration of the skin can be prevented.

The method for producing a skin of the present invention is a method for producing a skin having a molded sheet (X) of vinyl chloride resin and a molded sheet (Y) of foamed vinyl chloride resin, comprising the steps of: a step 1 of forming a vinyl chloride resin molded sheet (X) using a vinyl chloride resin composition (A) containing a vinyl chloride resin and a plasticizer; and a 2 nd step of forming a foamed vinyl chloride resin molded sheet (Y) on one side in the thickness direction of the vinyl chloride resin molded sheet (X) by using a foamable vinyl chloride resin composition (B), wherein the content of the plasticizer in the vinyl chloride resin composition (A) is 50 parts by mass or more per 100 parts by mass of the vinyl chloride resin. As described above, if the step of forming the molded vinyl chloride resin sheet using the vinyl chloride resin composition containing the vinyl chloride resin and the plasticizer and the step of forming the molded foamed vinyl chloride resin sheet on one side in the thickness direction of the molded vinyl chloride resin sheet using the foamable vinyl chloride resin composition are performed, the skin capable of satisfactorily suppressing heat shrinkage when used as a lining of a foamed polyurethane molded article can be produced.

In the method for producing the skin of the present invention, it is preferable that the foamable vinyl chloride resin composition (B) contains a thermal decomposition type foaming agent. When the foamable vinyl chloride resin composition (B) contains a thermal decomposition type foaming agent, the thermal shrinkage of the obtained skin when used as a foamed polyurethane molded article can be further favorably suppressed.

In the method for producing a skin of the present invention, the thermal decomposition type foaming agent preferably contains an azo compound. When the thermally decomposable foaming agent contains an azo compound, the thermal shrinkage of the resulting skin when used as a lining for a foamed polyurethane molded article can be further favorably suppressed.

Further, in the method for producing a skin of the present invention, it is preferable that the volume average particle diameter of the thermal decomposition type foaming agent is 10 μm or less. When the volume average particle diameter of the thermal decomposition type foaming agent is 10 μm or less, the hardness of the obtained skin can be reduced and the cushioning property can be improved.

The present invention is also directed to advantageously solve the above-mentioned problems, and a laminate of the present invention is characterized in that the foamed polyurethane molded article and any of the above-mentioned skins are provided, and the foamed vinyl chloride resin molded sheet (Y) is disposed between the foamed polyurethane molded article and the vinyl chloride resin molded sheet (X). In this manner, if the laminate is provided with the foamed polyurethane molded article and any of the skins described above, and the foamed vinyl chloride resin molded sheet (Y) is disposed between the foamed polyurethane molded article and the vinyl chloride resin molded sheet (X), thermal shrinkage can be favorably suppressed.

Effects of the invention

According to the present invention, it is possible to provide a skin that can satisfactorily suppress heat shrinkage when used with a foamed polyurethane molded article lined therein.

Further, according to the present invention, a laminate capable of satisfactorily suppressing thermal shrinkage of the skin can be provided.

Detailed Description

The embodiments of the present invention will be described in detail below.

Here, the skin of the present invention can be used, for example, for producing the laminate of the present invention. The skin of the present invention can be preferably used as an automobile interior material such as a skin of an automobile interior part such as an automobile instrument panel. The skin of the present invention can be produced by the skin production method of the present invention.

(epidermis)

The skin of the present invention is characterized by comprising a vinyl chloride resin molded sheet (X) containing a vinyl chloride resin and a predetermined amount of a plasticizer, and a foamed vinyl chloride resin molded sheet (Y), wherein the foamed vinyl chloride resin molded sheet (Y) is disposed on one side in the thickness direction of the vinyl chloride resin molded sheet (X). In addition, since the foamed vinyl chloride resin molding sheet (Y) is disposed on one side in the thickness direction of the vinyl chloride resin molding sheet (X), the skin of the present invention can satisfactorily suppress thermal shrinkage when used while lined with a foamed polyurethane molded article, that is, when used while further laminating a foamed polyurethane molded article on the side where the foamed vinyl chloride resin molding sheet (Y) is disposed. Therefore, the skin of the present invention can be preferably used as an automobile interior part, in particular, as a skin of an automobile interior part such as an automobile instrument panel and a door trim, and can be particularly preferably used as a skin of an automobile instrument panel.

< molded vinyl chloride resin sheet (X) >

The vinyl chloride resin molded sheet (X) can be obtained by molding a vinyl chloride resin composition (a) containing a vinyl chloride resin and a predetermined amount of a plasticizer into a sheet shape. The vinyl chloride resin molded sheet (X) is not a foam, unlike the foamed vinyl chloride resin molded sheet (Y) described later.

The thickness of the molded vinyl chloride resin sheet (X) is not particularly limited, but is preferably 0.1mm or more, more preferably 0.5mm or more, further preferably 0.7mm or more, further preferably 1.0mm or more, further preferably 1.2mm or more, preferably 5.0mm or less, more preferably 2.0mm or less, further preferably 1.8mm or less, and further preferably 1.5mm or less. This is because if the thickness of the molded vinyl chloride resin sheet (X) is not less than the lower limit, the obtained molded vinyl chloride resin sheet (X) can be provided with a good tensile elongation at low temperature. This is because, if the thickness of the molded vinyl chloride resin sheet (X) is not more than the upper limit, the obtained molded vinyl chloride resin sheet (X) is excellent in handling properties, and the foamed molded vinyl chloride resin sheet (Y) can be more easily arranged on the molded vinyl chloride resin sheet (X).

< vinyl chloride resin composition (A) >

The vinyl chloride resin composition (a) contains a vinyl chloride resin and a predetermined amount of a plasticizer, and may further optionally contain various additives.

In addition, the content of each component in the vinyl chloride resin composition (a) with respect to the vinyl chloride resin is equal to the content of each component in the vinyl chloride resin molded sheet (X) with respect to the vinyl chloride resin, except for the component that can be decomposed in the molding step.

[ vinyl chloride resin ]

The vinyl chloride resin contained in the vinyl chloride resin composition (a) may contain, for example, 1 or 2 or more types of vinyl chloride resin particles, and may further optionally contain 1 or 2 or more types of vinyl chloride resin fine particles. Among them, the vinyl chloride resin preferably contains at least vinyl chloride resin particles, and more preferably contains vinyl chloride resin particles and vinyl chloride resin fine particles.

In the present specification, "resin particles" mean particles having a particle diameter of 30 μm or more, and "fine resin particles" mean particles having a particle diameter of less than 30 μm. The vinyl chloride resin particles generally function as a matrix resin (base material), and the vinyl chloride resin fine particles generally function as a release agent (powder flowability improver). The vinyl chloride resin particles are preferably produced by a suspension polymerization method, and the vinyl chloride resin fine particles are preferably produced by an emulsion polymerization method.

The vinyl chloride resin can also be produced by any conventionally known production method such as suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization.

Composition-

Examples of the vinyl chloride resin include a homopolymer composed of vinyl chloride monomer units, and a vinyl chloride copolymer containing vinyl chloride monomer units in an amount of preferably 50% by mass or more, more preferably 70% by mass or more. Specific examples of the monomer (comonomer) copolymerizable with vinyl chloride monomer, which can constitute the vinyl chloride copolymer, include: olefins such as ethylene and propylene; halogenated olefins such as allyl chloride, vinylidene chloride, vinyl fluoride and chlorotrifluoroethylene; vinyl carboxylates such as vinyl acetate and vinyl propionate; vinyl ethers such as isobutyl vinyl ether and hexadecyl vinyl ether; allyl ethers such as allyl-3-chloro-2-oxypropyl ether and allyl glycidyl ether; unsaturated carboxylic acids, esters thereof, or anhydrides thereof such as acrylic acid, maleic acid, itaconic acid, 2-hydroxyethyl acrylate, methyl methacrylate, monomethyl maleate, diethyl maleate, and maleic anhydride; unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylamides such as acrylamide, N-methylolacrylamide, acrylamido-2-methylpropanesulfonic acid, and (meth) acrylamidopropyltrimethylammonium chloride; allylamine benzoate, allylamine such as diallyldimethylammonium chloride, and derivatives thereof. The monomers exemplified above are only a part of the comonomers, and as the comonomers, various monomers exemplified by "polyvinyl chloride" published by the ethylene department of the chemical Collection, Japan, Industrial News, Inc. (1988) pages 75 to 104 can be used. These comonomers may be used in a single amount of 1 kind, or in an amount of 2 or more kinds. The vinyl chloride resin also includes a resin obtained by graft polymerizing (1) vinyl chloride or (2) vinyl chloride and the above comonomer in a resin such as an ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl acrylate copolymer, or chlorinated polyethylene.

Here, in the present specification, "(meth) acrylic acid" means acrylic acid and/or methacrylic acid.

[ plasticizer ]

The vinyl chloride resin composition (a) further contains a plasticizer in a prescribed amount. If the vinyl chloride resin composition does not contain a plasticizer, a molded sheet of vinyl chloride resin cannot be obtained satisfactorily using the vinyl chloride resin composition.

Content-

Here, the content of the plasticizer is required to be 50 parts by mass or more, preferably 55 parts by mass or more, more preferably 60 parts by mass or more, further preferably 65 parts by mass or more, further preferably 70 parts by mass or more, further preferably 85 parts by mass or more, preferably 200 parts by mass or less, more preferably 170 parts by mass or less, further preferably 140 parts by mass or less, and further preferably 100 parts by mass or less, with respect to 100 parts by mass of the vinyl chloride resin. This is because if the content of the plasticizer is not less than the lower limit, excellent flexibility can be imparted to the vinyl chloride resin composition (a), and for example, the molded sheet (X) of vinyl chloride resin can be easily processed, and the obtained molded sheet (X) of vinyl chloride resin can be imparted with good tensile elongation at low temperature. Further, if the content of the plasticizer is not more than the upper limit, the adhesion of the surface of the obtained molded sheet (X) of vinyl chloride resin can be further suppressed, and the surface smoothness can be further improved.

Species-

Examples of the plasticizer include a primary plasticizer and a secondary plasticizer described in international publication No. 2016/098344. These components can be used alone in 1 kind, also can be used in any ratio of combination of 2 or more.

Among the above plasticizers, from the viewpoint of easily obtaining the vinyl chloride resin composition (a) and the vinyl chloride resin molded sheet (X), it is preferable to use at least a primary plasticizer, and it is more preferable to use a primary plasticizer and a secondary plasticizer in combination as the plasticizer. Specifically, as the plasticizer, trimellitate and/or pyromellitate are preferably used, and at least trimellitate is more preferably used, and trimellitate and epoxidized soybean oil are further preferably used in combination.

[ additives ]

The vinyl chloride resin composition (a) may further contain various additives in addition to the above components. The additive is not particularly limited, and examples thereof include: stabilizers such as perchloric acid-treated hydrotalcite, zeolite, β -diketone and fatty acid metal salt; a release agent; a release agent other than the vinyl chloride resin fine particles; an impact resistance improver; perchloric acid compounds (sodium perchlorate, potassium perchlorate, etc.) other than the perchloric acid-treated hydrotalcite; an antioxidant; a mold inhibitor; a flame retardant; an antistatic agent; a filler; a light stabilizer; molding processability modifier (silicone oil, etc.); a colorant.

Such an additive is not particularly limited, and for example, an additive described in international publication No. 2016/098344 (except for a foaming agent) can be used.

[ method for producing vinyl chloride resin composition (A) ]

The vinyl chloride resin composition (a) is not particularly limited, and can be prepared by mixing the above components.

Here, the method of mixing the vinyl chloride resin, the predetermined amount of the plasticizer, and, if necessary, various additives is not particularly limited, and examples thereof include the following methods: the components other than the release agent containing the vinyl chloride resin fine particles are mixed by dry blending, and thereafter, the release agent is added and mixed. Here, the dry blending preferably uses a Henschel (Henschel) mixer. The temperature at the time of dry blending is not particularly limited, but is preferably 50 ℃ or higher, more preferably 70 ℃ or higher, and preferably 200 ℃ or lower.

< molded foam vinyl chloride resin sheet (Y) >

The skin of the present invention has a molded sheet (Y) of foamed vinyl chloride resin disposed on one side in the thickness direction of the molded sheet (X) of vinyl chloride resin. Further, the molded sheet (Y) of foamed vinyl chloride resin is preferably located on one surface in the thickness direction of the skin of the present invention. In the present invention, the surface of the skin on one side in the thickness direction may be partially formed of the foamed vinyl chloride resin molded sheet (Y) or may be entirely formed of the foamed vinyl chloride resin molded sheet (Y).

Here, it is generally considered that when the skin formed of the molded sheet of vinyl chloride resin containing a plasticizer is left under high temperature conditions in a state of being in direct contact with the foamed polyurethane molded body, for example, the plasticizer in the skin is transferred to the foamed polyurethane molded body, whereby the amount of the plasticizer in the skin is reduced and the skin is thermally shrunk. However, it is presumed that if the skin of the present invention in which the foamed vinyl chloride resin molding sheet (Y) is disposed on one side in the thickness direction of the vinyl chloride resin molding sheet (X) containing the plasticizer, the foamed vinyl chloride resin molding sheet (Y) is interposed between the vinyl chloride resin molding sheet (X) and the foamed polyurethane molded body, and the plasticizer is less likely to migrate from the vinyl chloride resin molding sheet (X) and the foamed vinyl chloride resin molding sheet (Y) and reach the foamed polyurethane molded body, and as a result, thermal shrinkage can be favorably suppressed.

The foamed vinyl chloride resin molding sheet (Y) may be directly bonded to the vinyl chloride resin molding sheet (X), and the foamed vinyl chloride resin molding sheet (Y) may be bonded to the vinyl chloride resin molding sheet (X) via another resin layer or the like as long as the desired effect is obtained.

The thickness of the molded sheet (Y) of the foamed vinyl chloride resin is not particularly limited, but is preferably 1.5mm or more, more preferably 1.8mm or more, further preferably 2.0mm or more, further preferably 2.3mm or more, further preferably 2.5mm or more, preferably 10.0mm or less, more preferably 5.0mm or less, further preferably 4.0mm or less, further preferably 3.0mm or less, and further preferably 2.7mm or less. When the thickness of the molded sheet (Y) of a foamed vinyl chloride resin is not less than the lower limit, the resulting skin can be used while lining the foamed polyurethane molded article, and the heat shrinkage of the skin can be further favorably suppressed, and the hardness of the skin can be reduced to improve the cushioning property. On the other hand, if the thickness of the molded sheet (Y) of foamed vinyl chloride resin is not more than the upper limit, the obtained skin is excellent in workability in lining the foamed polyurethane molded article.

The foamed vinyl chloride resin molded sheet (Y) is not particularly limited, and is usually obtained by foaming and molding the foamable vinyl chloride resin composition (B) into a sheet.

< foamable vinyl chloride resin composition (B) >

The foamable vinyl chloride resin composition (B) contains a vinyl chloride resin and a foaming agent, and may further optionally contain an acrylic polymer, a plasticizer, other various additives, and the like.

As the vinyl chloride resin contained in the foamable vinyl chloride resin composition (B), the vinyl chloride resin contained in the vinyl chloride resin composition (a) described above in the section of "molded sheet (X) of vinyl chloride resin" can be used.

The kind of plasticizer that can be contained in the foamable vinyl chloride resin composition (B) can be appropriately selected from the range of the kind of plasticizer in the vinyl chloride resin composition (a) in the section of "vinyl chloride resin molded sheet (X)". The content of the plasticizer in the foamable vinyl chloride resin composition (B) is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, still more preferably 80 parts by mass or more, yet more preferably 85 parts by mass or more, preferably 200 parts by mass or less, more preferably 170 parts by mass or less, and still more preferably 140 parts by mass or less, per 100 parts by mass of the vinyl chloride resin. If the content of the plasticizer in the foamable vinyl chloride resin composition (B) is not less than the lower limit, the hardness of the skin can be reduced and the cushioning properties can be improved. On the other hand, if the content of the plasticizer in the foamable vinyl chloride resin composition (B) is not more than the upper limit, the foamed vinyl chloride resin molded sheet (Y) does not become too soft, and the obtained skin is excellent in workability in lining the foamed polyurethane molded article.

Further, as various additives that can be contained in the foamable vinyl chloride resin composition (B) in addition to the foaming agent and the plasticizer, the additives that can be contained in the vinyl chloride resin composition (a) described above in the section of "molded sheet (X) of vinyl chloride resin" can also be used.

In addition to the components such as a thermal decomposition type foaming agent described later which can be decomposed in the molding step, the content of each component in the foamable vinyl chloride resin composition (B) with respect to the vinyl chloride resin is equal to the content of each component in the foamed vinyl chloride resin molded article (Y) with respect to the vinyl chloride resin.

[ foaming agent ]

The foamable vinyl chloride resin composition (B) contains a foaming agent. When the foamable vinyl chloride resin composition (B) contains a foaming agent, the foamable vinyl chloride resin composition (B) can be foamed and molded, and a foamed vinyl chloride resin molded sheet (Y) can be favorably obtained.

As the foaming agent contained in the foamable vinyl chloride resin composition (B), a chemical foaming agent, a physical foaming agent, and the like can be used.

Examples of the chemical foaming agent include a thermal decomposition type foaming agent and a reaction type foaming agent.

Further, as the thermal decomposition type foaming agent, organic thermal decomposition type foaming agents such as azo compounds, nitroso compounds, hydrazine derivatives, semicarbazide compounds, tetrazole compounds, organic acids, and the like; inorganic thermal decomposition type foaming agents such as bicarbonates, carbonates, organic acid salts and nitrites.

Further, examples of the azo compound include azodicarbonamide (ADCA), Azobisisobutyronitrile (AIBN), barium azodicarboxylate, diazoaminobenzene, and the like. Examples of the nitroso compound include Dinitrosopentamethylenetetramine (DPT).

Examples of the hydrazine derivative include p, p' -oxybis (benzenesulfonylhydrazide) (OBSH), p-Toluenesulfonylhydrazide (TSH), and Hydrazonodicarboxamide (HDCA).

Examples of the semicarbazide compound include p-toluenesulfonyl semicarbazide. Examples of the tetrazole compound include 5-phenyltetrazole, 1, 4-bitetrazole, and the like.

Examples of the organic acid include polycarboxylic acids such as citric acid, oxalic acid, fumaric acid, phthalic acid, malic acid, and tartaric acid.

Examples of the reactive blowing agent include a combination of an isocyanate compound and water, a combination of sodium hydrogencarbonate and an acid, a combination of hydrogen peroxide and yeast, and a combination of zinc powder and an acid.

On the other hand, examples of the physical blowing agent include: gases such as freon gas and carbon dioxide gas; volatile liquids such as water and volatile hydrocarbon compounds; thermally expandable microcapsules containing such a gas or volatile liquid.

Among the above-mentioned foaming agents, a thermal decomposition type foaming agent is preferably used, an azo compound is more preferably used, and azodicarbonamide (ADCA) is particularly preferably used. When a thermal decomposition type foaming agent is used as the foaming agent, the thermal shrinkage when the obtained skin-lined foamed polyurethane molded article is used can be further favorably suppressed, and when an azo compound is used as the thermal decomposition type foaming agent, the thermal shrinkage when the obtained skin-lined foamed polyurethane molded article is used can be further favorably suppressed.

The volume average particle diameter of the thermal decomposition type foaming agent is preferably 30 μm or less, more preferably 20 μm or less, further preferably 10 μm or less, further preferably 7 μm or less, further preferably 5 μm or less, further more preferably 4 μm or less, most preferably 3 μm or less, and preferably 1 μm or more. When the volume average particle diameter of the thermal decomposition type foaming agent is not more than the upper limit, the expansion ratio of the foamable vinyl chloride resin composition (B) can be increased, the hardness of the obtained skin can be decreased, and the cushioning property can be improved. On the other hand, if the volume average particle diameter of the thermal decomposition type foaming agent is not less than the lower limit, the workability of the thermal decomposition type foaming agent is excellent.

In the present specification, the "volume average particle diameter" refers to a particle diameter (median diameter) at which the cumulative volume calculated from the small diameter side becomes 50% in the particle diameter distribution (volume basis) measured by using a laser diffraction/scattering particle diameter distribution measuring apparatus.

The content of the thermal decomposition type foaming agent in the foamable vinyl chloride resin composition (B) is preferably 0.7 parts by mass or more, more preferably 1.4 parts by mass or more, further preferably 2.1 parts by mass or more, and preferably 4 parts by mass or less, based on 100 parts by mass of the vinyl chloride resin. When the content of the thermal decomposition type foaming agent is not less than the lower limit, the expansion ratio of the foamable vinyl chloride resin composition (B) can be increased, the hardness of the obtained skin can be decreased, and the cushioning property can be improved. On the other hand, if the content of the thermal decomposition type foaming agent is not more than the upper limit, the uniformity of the cells is improved, and therefore the hardness of the skin obtained can be substantially uniformly reduced at all positions, and the cushioning property can be improved.

[ acrylic Polymer ]

The foamable vinyl chloride resin composition (B) preferably contains an acrylic polymer. Since the foamable vinyl chloride resin composition (B) contains the acrylic polymer, the uniformity of the cells (bubbles) in the foamed vinyl chloride resin molded sheet (Y) is improved, and therefore, the hardness of the obtained skin can be reduced substantially uniformly at all positions, and the cushioning property can be improved.

Here, in the present invention, the "acrylic polymer" refers to a polymer containing a structural unit derived from a (meth) acrylate such as an alkyl acrylate, an alkyl methacrylate, an alkoxyalkyl acrylate, and an alkoxyalkyl methacrylate. Herein, "(meth) acrylate" means "acrylate and/or methacrylate". The acrylic polymer is not particularly limited, and a copolymer of an alkyl methacrylate and an alkyl acrylate (alkyl methacrylate-alkyl acrylate copolymer) is preferably used. When a copolymer of an alkyl methacrylate and an alkyl acrylate is used as the acrylic copolymer, the uniformity of the cells (cells) in the molded sheet (Y) of the foamed vinyl chloride resin is further improved, and therefore the hardness of the obtained skin can be further reduced, and the cushioning properties can be further improved.

The acrylic polymer can be prepared by polymerization using a monomer composition C containing a (meth) acrylate and optionally other compounds as monomers.

Examples of the (meth) acrylic ester monomer that can be used for the production of the acrylic polymer include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, and 2-ethylhexyl acrylate; and alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, and 2-ethylhexyl methacrylate. These can be used alone in 1 kind, also can be combined with more than 2 kinds. Among these, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate are preferably used.

The proportion of the (meth) acrylate monomer in the total monomers in the monomer composition C is preferably 50 mass% or more and 95 mass% or less. If the ratio of the (meth) acrylate monomer to the total monomers in the monomer composition is not less than the lower limit, the uniformity of the cells (bubbles) in the molded sheet (Y) of the foamed vinyl chloride resin is further improved, and therefore, the hardness of the obtained skin can be further reduced, and the cushioning properties can be further improved. On the other hand, if the ratio of the (meth) acrylate monomer to the total monomers in the monomer composition is not more than the upper limit, the acrylic polymer can be prevented from being fused by heat or the like.

The monomer other than the (meth) acrylate that can be contained in the monomer composition C is not particularly limited, and examples thereof include an ethylenically unsaturated carboxylic acid monomer and an α, β -unsaturated nitrile monomer.

As the ethylenically unsaturated carboxylic acid monomer, at least one of an ethylenically unsaturated carboxylic acid and a salt thereof can be used. Examples of the ethylenically unsaturated carboxylic acid include ethylenically unsaturated monocarboxylic acids and derivatives thereof, ethylenically unsaturated dicarboxylic acids and anhydrides thereof, and derivatives thereof. Examples of the ethylenically unsaturated carboxylic acid salt include sodium salts, potassium salts, and lithium salts of ethylenically unsaturated carboxylic acids.

The ethylenically unsaturated carboxylic acid and its salt may be used alone in 1 kind, or may be used in combination in an arbitrary ratio in 2 or more kinds.

Examples of the ethylenically unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, and crotonic acid. Further, examples of the derivative of the ethylenically unsaturated monocarboxylic acid include 2-ethacrylic acid, isocrotonic acid, α -acetoxyacrylic acid, β -trans-aryloxyacrylic acid, α -chloro- β -E-methoxyacrylic acid, β -diaminoacrylic acid, and the like.

Further, examples of the ethylenically unsaturated dicarboxylic acid include maleic acid, fumaric acid, itaconic acid, and the like. Further, examples of the acid anhydride of the ethylenically unsaturated dicarboxylic acid include maleic anhydride, acrylic anhydride, methyl maleic anhydride, and dimethyl maleic anhydride. Further, examples of the derivative of the ethylenically unsaturated dicarboxylic acid include methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, chloro maleic acid, dichloro maleic acid, fluoro maleic acid, and the like.

Further, the α, β -unsaturated nitrile monomer includes acrylonitrile and methacrylonitrile. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

Further, as the acrylic polymer, commercially available products can be used. In particular, "MetablenL-1000" (manufactured by Mitsubishi Chemical Co., Ltd.) can be preferably used as the copolymer of the alkyl methacrylate and the alkyl acrylate.

The content of the acrylic polymer in the foamable vinyl chloride resin composition (B) is preferably 0.01 part by mass or more, more preferably 0.09 part by mass or more, further preferably 0.2 part by mass or more, preferably 1 part by mass or less, more preferably 0.5 part by mass or less, per 100 parts by mass of the vinyl chloride resin. If the content of the acrylic polymer is within the above-mentioned predetermined range, the uniformity of the cells in the molded sheet (Y) of the foamed vinyl chloride resin is further improved, and therefore, the hardness of the obtained skin can be further reduced, and the cushioning property can be further improved.

[ Process for producing Expandable vinyl chloride resin composition (B) ]

The foamable vinyl chloride resin composition (B) is not particularly limited, and can be prepared by mixing the above components.

Here, the method of mixing the vinyl chloride resin, the foaming agent, and, if necessary, an acrylic polymer, a plasticizer, and other various additives is not particularly limited, and examples thereof include the following methods: the components other than the release agent containing vinyl chloride resin fine particles and the foaming agent are mixed by dry blending, and thereafter, the release agent and the foaming agent are added and mixed. Here, the dry blending preferably uses a henschel mixer. The temperature at the time of dry blending is not particularly limited, but is preferably 50 ℃ or higher, more preferably 70 ℃ or higher, and preferably 200 ℃ or lower. The temperature at the time of adding the foaming agent can be arbitrarily set in a range in which the desired effects of the present invention can be obtained, depending on the type of the foaming agent used.

(method for producing skin)

The method for producing a skin of the present invention is a method for producing a skin having a molded sheet (X) of vinyl chloride resin and a molded sheet (Y) of foamed vinyl chloride resin, comprising the steps of: a step 1 of forming a vinyl chloride resin molded sheet (X) using a vinyl chloride resin composition (A) containing a vinyl chloride resin and a plasticizer; and a 2 nd step of forming a foamed vinyl chloride resin molded sheet (Y) on one side in the thickness direction of the vinyl chloride resin molded sheet (X) by using a foamable vinyl chloride resin composition (B), wherein the content of the plasticizer in the vinyl chloride resin composition (A) is 50 parts by mass or more per 100 parts by mass of the vinyl chloride resin. According to the method for producing a skin of the present invention, a skin in which heat shrinkage can be favorably suppressed when used as a lining of a foamed polyurethane molded body can be produced.

< step 1 >

In the step 1, a vinyl chloride resin molded sheet (X) is formed using a vinyl chloride resin composition (a) containing a vinyl chloride resin and a predetermined amount of a plasticizer. Further, the vinyl chloride resin composition (a) is usually molded into a sheet shape by a known molding method, thereby forming a molded sheet (X) of a vinyl chloride resin.

Here, as the vinyl chloride resin composition (a), the vinyl chloride resin composition (a) used in the formation of the vinyl chloride resin molded sheet (X) described in the section of "skin" can be used.

Further, as the molding method, powder molding is preferably used, and more preferably powder slush molding is used.

Here, the mold temperature at the time of powder slush molding is not particularly limited, but is preferably 200 ℃ or more, more preferably 220 ℃ or more, preferably 300 ℃ or less, and more preferably 280 ℃ or less.

The method for producing the vinyl chloride resin molded sheet (X) is not particularly limited, and the following method can be used, for example. That is, after the vinyl chloride resin composition (a) is sprayed into a mold in the above temperature range and left to stand for 5 seconds to 30 seconds, the remaining vinyl chloride resin composition (a) is shaken off, and left to stand at an arbitrary temperature for 30 seconds to 3 minutes. Thereafter, the molded vinyl chloride resin sheet (X) obtained may or may not be released from the mold by cooling the mold to 10 ℃ or higher and 60 ℃ or lower, according to the embodiment of step 2 described later. Further, the vinyl chloride resin molded sheet which was released from the mold can be obtained as a sheet-like molded body which, for example, follows the shape of the mold.

< 2 nd step >

In the 2 nd step, a foamed vinyl chloride resin molded sheet (Y) is formed on one side of the vinyl chloride resin molded sheet (X) in the thickness direction using the foamable vinyl chloride resin composition (B).

Here, as the foamable vinyl chloride resin composition (B), the foamable vinyl chloride resin composition (B) used for forming the foamed vinyl chloride resin molded sheet (Y) described in the section of "skin" can be used.

The method for forming the foamed vinyl chloride resin molded sheet (Y) on one side in the thickness direction of the vinyl chloride resin molded sheet (X) using the foamable vinyl chloride resin composition (B) is not particularly limited, and the following methods can be employed: after a foamed vinyl chloride resin molded sheet (Y) alone is produced by foaming and molding the foamable vinyl chloride resin composition (B) into a sheet by the known molding method described in the section of "step 1", the foamed vinyl chloride resin molded sheet (Y) is bonded to one side in the thickness direction of the vinyl chloride resin molded sheet (X) by a known bonding method, and the following method can be used: the powder slush molding as the 1 st step and the powder slush molding as the 2 nd step (sometimes referred to as "double slush molding") are continuously performed using the same mold.

That is, in the above-mentioned powder slush molding as the first step 1, the remaining vinyl chloride resin composition (a) is shaken out from the mold, and further, after leaving at an arbitrary temperature for 30 seconds or more and 3 minutes or less, the obtained molded vinyl chloride resin sheet (X) is not released from the mold, and as the second step 2, the powder of the foamable vinyl chloride resin composition (B) is sprayed and foamed in the mold with the molded vinyl chloride resin sheet (X). Here, the mold temperature when spraying the powder of the foamable vinyl chloride resin composition (B) is not particularly limited, but is preferably 200 ℃ or higher, more preferably 220 ℃ or higher, preferably 300 ℃ or lower, and more preferably 280 ℃ or lower. After leaving for 5 to 30 seconds, the remaining foamable vinyl chloride resin composition (B) is shaken off, and further left at an arbitrary temperature for 30 to 3 minutes. Thereafter, the mold is cooled to 10 ℃ or higher and 60 ℃ or lower, and the obtained skin is released from the mold. The mold-released skin is a molded article having a 2-layer structure in which a foamed vinyl chloride resin molded sheet (Y) is disposed on one side in the thickness direction of a vinyl chloride resin molded sheet (X), and the whole skin obtained in one example of the above-described manufacturing method is a sheet-like molded article having a shape conforming to the shape of a mold. As described above, if the powder slush molding is continuously performed 2 times using the same mold as the 1 st step and the 2 nd step in the method for producing a skin of the present invention, a skin in which thermal shrinkage can be favorably suppressed when used with a foamed polyurethane molded product lined can be efficiently produced.

In the above description, the case of producing the skin in which the foamed vinyl chloride resin molded sheet (Y) is directly bonded to one surface of the vinyl chloride resin molded sheet (X) in the thickness direction by the skin producing method of the present invention has been described, but the skin producing method of the present invention is not limited thereto. For example, the method for producing a skin of the present invention can produce a skin in which a molded sheet (X) of vinyl chloride resin and a molded sheet (Y) of foamed vinyl chloride resin are bonded to each other via another resin layer or the like by including any step other than the above-described 1 st step and 2 nd step.

(laminated body)

The laminate of the present invention has a foamed polyurethane molded article and the skin described above. The laminate of the present invention has a structure in which the foamed vinyl chloride resin molded sheet (Y) is disposed between the foamed polyurethane molded article and the vinyl chloride resin molded sheet (X). In addition, usually, the foamed polyurethane molded body lines the foamed vinyl chloride resin molded sheet (Y) side in the skin, and the foamed polyurethane molded body and the skin are adjacent in the lamination direction (that is, the foamed polyurethane molded body and the vinyl chloride resin molded sheet (X) are laminated in the lamination direction via the foamed vinyl chloride resin molded sheet (Y)). In the laminate of the present invention, the foamed vinyl chloride resin molded sheet (Y) is interposed between the foamed polyurethane molded article and the vinyl chloride resin molded sheet (X), and therefore, thermal shrinkage can be favorably suppressed. Therefore, the laminate of the present invention can be preferably used as an automobile interior material for automobile interior parts such as an automobile instrument panel and a door trim, and particularly, can be preferably used as an automobile instrument panel.

Here, the lamination method is not particularly limited, and the following method can be used, for example. That is, an isocyanate as a raw material of the foamed polyurethane molded article is reacted with a polyol or the like on the surface of the skin on the side where the foamed vinyl chloride resin molded sheet (Y) is disposed, and polymerization is carried out, and foaming of polyurethane is carried out by a known method, whereby the foamed polyurethane molded article is directly formed on the skin.