JP2002293952A - Interior material for vehicle having excellent matte appearance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interior material for a vehicle such as automobile composed of a soft vinyl chloride resin having excellent matte appearance, weather resistance and formability. SOLUTION: The interior material for vehicle is composed of a skin layer and an inner layer constituting the core material. The soft vinyl chloride resin composition constituting the skin material is produced by compounding 100 pts.wt. of a partly crosslinked polyvinyl chloride resin with 20-200 pts.wt. of a plasticizer, 1-30 pts.wt. of a methyl methacrylate copolymer having a weight- average molecular weight of >=3,000,000 and 0.05-3 pts.wt. of a hindered amine light stabilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interior part for a vehicle, such as an automobile, which is injection-molded from a soft vinyl chloride resin composition and has excellent mattability, weather resistance and moldability. It is.

[0002]

2. Description of the Related Art A skin material such as an armrest, a shift lever knob, or an assist grip, which is an interior part for a vehicle such as an automobile, is often made of a polyvinyl chloride resin composition which is excellent in function while being low in cost. ing. These interior parts for vehicles usually use an inner layer as a core material for maintaining the shape of the product and a soft vinyl chloride resin composition that enhances the design, scratch resistance, weather resistance, flexibility, etc. of the product. In many cases, it is composed of a covered skin layer. In addition, these products are required to have excellent matting properties in order to bring out the luxury of the interior of the vehicle. For this reason, a method of enhancing mattability by a soft vinyl chloride resin composition using a partially crosslinked polyvinyl chloride resin is generally used.

[0003]

However, the soft vinyl chloride resin composition using the partially cross-linked polyvinyl chloride resin is a soft vinyl chloride resin composition using a non-cross-linked polyvinyl chloride resin. There is a problem that fluidity, thermal stability and weather resistance are inferior to resin compositions.

[0004] Regarding fluidity, a difference in melt viscosity between a crosslinked portion and an uncrosslinked portion in a partially crosslinked polyvinyl chloride resin occurs, so that the flow when flowing through a mold becomes unstable, There has been a problem of causing a flow mark phenomenon (a mottling of a tiger pattern occurs on the product surface). As a measure against the flow mark, a method of increasing the resin temperature or the mold temperature has been adopted.However, even a soft vinyl chloride resin composition using a partially crosslinked polyvinyl chloride resin has a high temperature. However, there is a problem that a desired matte sensation cannot be obtained because gloss is produced if molded in the following manner.

[0005] The thermal stability can be compensated for by increasing the amount of the stabilizer, but the weather resistance has a problem in that the plasticizer bleeds out. That is, since the crosslinked portion in the partially crosslinked polyvinyl chloride resin has a small ability to absorb the plasticizer and a small ability to retain the absorbed plasticizer, the partially crosslinked polyvinyl chloride resin has a small capacity. Compared to vinyl resins, plasticizers (especially plasticizers of low molecular weight due to weather resistance degradation) cause bleed-out.

Accordingly, the present inventors have:
As a result of intensive research to solve the above problems, by adding a specific amount of a methyl methacrylate copolymer having a specific molecular weight, the flow mark phenomenon is improved, and a hindered amine light stabilizer is added in a specific amount. As a result, it was found that the weather resistance could be improved, and the present invention was completed.

[0006] That is, the present invention relates to an injection molded interior part for a vehicle, in which a soft vinyl chloride resin composition as a skin material is used as a plasticizer with respect to 100 parts by weight of a partially crosslinked polyvinyl chloride resin. 20-200 parts by weight, weight average molecular weight 3
An interior material for vehicles excellent in mattness, characterized by comprising 1 to 30 parts by weight of a methyl methacrylate-based copolymer of 1,000,000 or more and 0.05 to 3 parts by weight of a hindered amine light stabilizer.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the partially cross-linked polyvinyl chloride resin used in the soft vinyl chloride resin composition serving as the skin material of the present invention comprises a vinyl chloride monomer or a vinyl chloride monomer and another monomer. Is obtained by adding a polyfunctional monomer in an amount corresponding to a desired degree of cross-linking to the polymerization system when the mixture is subjected to suspension polymerization.

[0008] Here, polyfunctional monomers include monomers containing two or more ethylenic double bonds in the molecule, for example, diallyl esters of phthalic acid such as diallyl phthalate, diallyl maleate, diallyl fumarate, diallyl Diallyl esters of ethylenically unsaturated dibasic acids such as itaconate, diallyl ethers, triallyl cyanurate, divinyl ethers such as ethylene glycol divinyl ether, n-butanediol divinyl ether, ethylene glycol diacrylate, ethylene glycol dimethacrylate And di (meth) acrylates of polyhydric alcohols such as polyethylene glycol dimethacrylate.

It is desirable that the polyfunctional monomer is added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of a vinyl chloride monomer or a mixture of a vinyl chloride monomer and another monomer.

Other monomers include vinyl acetates such as vinyl acetate and vinyl propionate, and (meth) acrylates such as methyl methacrylate, ethyl methacrylate, methyl acrylate, and ethyl acrylate; Olefinic acids such as ethylene and propylene, maleic anhydride,
Acrylonitrile, styrene, etc., which are
Used alone or in combination of two or more.

[0011] The partially crosslinked polyvinyl chloride resin has a gel content insoluble in tetrahydrofuran (THF) of 5 to 90% by weight,
It is preferably 15 to 50% by weight. If the gel content is less than 5% by weight, the matting effect is insufficient, and if it exceeds 90% by weight, the mechanical strength is reduced and the moldability is remarkably deteriorated.

These partially crosslinked polyvinyl chloride resins having an average degree of polymerization in the range of 300 to 2000 are used in view of the balance between mechanical strength and fluidity. If the degree is less than 300, the mechanical strength is weak, and the plasticizer has poor holding power.Therefore, the plasticizer may migrate toward the skin layer. And the flow mark phenomenon also occurs, which is not preferable.

The plasticizer used in the present invention may be any one which is compatible with the above-mentioned vinyl chloride resin, such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and di-n-phthalate. Phthalates such as octyl, diisodecyl phthalate, butylbenzyl phthalate or phthalates of higher alcohols having about 11 to 13 carbon atoms; aliphatics such as dibutyl adipate, di-n-hexyl adipate and dibutyl sebacate Dibasic acid esters; Tributyl phosphate, tri-2-n-ethylhexyl phosphate, tricresyl phosphate, triphenyl phosphate, etc .; phosphate esters; trimellitic acid-tri-2-ethylhexyl, tributyl trimellitate, etc. Trimellitic acid esters; glycol es such as pentaerythritol ester and diethylene glycol benzoate Terps; epoxidized esters such as epoxidized soybean oil and epoxidized linseed oil; citrates such as acetyl tributyl citrate, acetyl trioctyl citrate and tri-n-butyl citrate; tetra-n-octyl pyro Melitate, polypropylene adipate, other polyester-based plasticizers and the like are used, and these are used alone or in combination of two or more. These plasticizers are added to 100 parts by weight of the above partially crosslinked polyvinyl chloride resin.
It is added in the range of 0 to 200 parts by weight. If the amount is less than 20 parts by weight, sufficient flexibility cannot be obtained and the fluidity deteriorates, so that it is not preferable. If the amount exceeds 200 parts by weight, not only the strength may be reduced but also broken, but also bleed out and stickiness may be caused. Therefore, it is not suitable as a product held by human hands.

The methyl methacrylate copolymer having a weight average molecular weight of 3,000,000 or more according to the present invention is a copolymer of methyl methacrylate and an acrylate ester. For example,
Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, and the like. Used alone or in combination of two or more. When the weight average molecular weight of these methyl methacrylate-based copolymers is less than 3,000,000, it is necessary to add a large amount to completely eliminate the flow mark phenomenon, which is not only economically disadvantageous, It is not preferable because it changes the function of the material. In addition, these methyl methacrylate copolymers are 1 to 30 parts by weight based on 100 parts by weight of the partially crosslinked polyvinyl chloride resin,
It is preferably used in the range of 2 to 10 parts by weight. If this is less than 1 part by weight, the flow mark phenomenon will occur,
If the amount is more than 30 parts by weight, the melt elasticity becomes too high and the fluidity is impaired, which is not preferable.

[0015] The hindered amine light stabilizer used in the present invention is not particularly limited as long as it is generally used for plastics, and may be a commercially available one. As a commercial product, for example, Asahi Denka Kogyo Adeka
Stubs LA-57, LA-62, LA-63, LA-67, LA-68, LA-77, LA
-87 and Sankyo LS-765, LS-744, LS-1114 from Sankyo are known. The hindered amine light stabilizer is added in an amount of 0.05 to 3 parts by weight, preferably 0.5 to 2 parts by weight, based on the partially crosslinked polyvinyl chloride resin. If the amount is less than 0.05 part by weight, bleed out of the plasticizer cannot be suppressed, and if it exceeds 5 parts by weight, the hindered amine-based light stabilizer itself undesirably causes bloom out.

The mechanism by which the hindered amine light stabilizer improves the weather resistance of the flexible vinyl chloride resin composition of the present invention not only suppresses the weather resistance deterioration of the vinyl chloride resin as a polymer, but also suppresses the plasticity in the composition. It is thought that the weathering deterioration of the agent was also suppressed. That is, the cause of the bleed out of the soft vinyl chloride resin composition deteriorated in weather resistance is that the vinyl chloride resin is deteriorated in weather resistance and the holding power of the plasticizer is reduced, and the plasticizer is degraded due to the deterioration in weather resistance. It is thought that both are considered to be the causes. When the partially crosslinked polyvinyl chloride resin as in the present invention is used, the effect is particularly exhibited because the plasticizer holding power of the original vinyl chloride resin is weak.

[0017] The soft vinyl chloride-based resin composition serving as the skin material of the present invention may contain, if necessary, stabilizers, lubricants, modifiers, fillers, coloring agents, and the like generally used in vinyl chloride-based resins. Can be added and blended in a range that does not impair the object of the present invention. As a stabilizer, for example, tribasic lead sulfate,
Lead-based stabilizers such as dibasic lead phosphite, basic lead sulfite, dibasic lead phthalate, lead white, lead laurate or stearate; butyltin malate, octyltin malate,
Di-n-alkyltin mercaptide, di-n-alkyltin dilaurate, dibutyltin dimaleate, dibutyltin lauryl mercaptide, di-octyltin S, S'-bis- (isooctyl
-Mercaptoacetate), dibutyltin bis-isooctylthioglycolate, di- (n-octyl) tin maleate polymer, tin-based stabilizer such as dibutyltin mercaptopropionate; calcium, cadmium, barium or zinc laurate or Organic metal salt stabilizers such as stearates and metal soap stabilizers; antimony stabilizers such as antimony mercaptocarboxylate or ester salts; phosphate stabilizers; epoxidized soybean oil, epoxidized linseed oil, etc. Examples include epoxidized oil stabilizers, ultraviolet absorbers such as hindered phenols such as bisphenol dimerized with BHT, sulfur, and methylene groups, salicylic acid esters, benzophenone, and benzotriazole. It is used in combination with the above.

Examples of the lubricant include aliphatic hydrocarbon lubricants such as low molecular wax, polyethylene wax, paraffin wax and liquid paraffin; higher aliphatic alcohol lubricants such as stearyl alcohol; stearamide, palmitamide, methylene Aliphatic amide-based lubricants such as bis-stearamide; fatty acid ester-based lubricants such as glyceryl monostearate, ethyl diaminostearate, and butyl stearate; or metal soaps, and these may be used alone or in combination of two or more. Used in combination.

[0019] Examples of the modifier include ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, chlorinated polyethylene, methyl methacrylate-butadiene-styrene copolymer, acrylonitrile-butadiene.
Impact modifiers such as styrene copolymers and acrylic rubbers;
Gelling accelerators such as polymethyl methacrylate; heat resistance modifiers such as acrylonitrile / butadiene / α-methylstyrene copolymer, methyl methacrylate / acrylate copolymer, and other copolymers using maleimide; Flame retardants such as aluminum hydroxide, sodium antimonate, phosphate esters and phosphate compounds, chlorinated paraffins, chlorinated olefins, hexabromobenzene; elasticity imparting agents such as partially cross-linked NBR, acrylic rubber, polyurethane; Is arbitrarily selected from a foaming agent, an antistatic agent, a surfactant, a conductivity-imparting agent and the like, and used alone or in combination of two or more.

As the filler, for example, magnesium carbonate,
Carbonates such as dawsonite; oxides such as silica, diatomaceous earth, and titanium oxide; hydroxides such as aluminum hydroxide and magnesium hydroxide; (sulfites) such as calcium sulfate and barium sulfate; talc Silicates such as clay, mica and calcium silicate; carbons such as carbon black and graphite; inorganic fibers such as hollow or solid glass beads, glass short fibers, metal fibers, carbon short fibers and carbon fibers; Metal powders such as iron powder and copper powder; heat-resistant resins such as polyimide and silicone; and the like.
Used alone or in combination of two or more.

As the coloring agent, any one can be selected from those conventionally used for coloring plastics. Examples of such a coloring agent include aluminum powder, metal powders such as bronze powder, carbon salts such as carbon black, titanium oxide, zinc oxide, oxides such as porcelain, sulfates such as precipitated barium sulfate, Carbonates such as calcium carbonate and basic magnesium carbonate; silicates such as clay and ultramarine; chromates such as graphite;
Inorganic pigments such as aluminates such as cobalt blue, and ferrocyan compounds such as dark blue; azo pigments such as toluidine red, permanent carmine FB, disazo yellow AAA, lake red C, phthalocyanine blue, indanthrone blue, quinacridone red, etc. Dyeing lakes such as polycyclic pigments, Victoria Pure Blue BO Lake, and Alkaline Blue Toner; organic pigments such as azine pigments and fluorescent pigments; and dyes such as basic dyes, acid dyes, oil-soluble dyes, and disperse dyes These are used singly or in combination of two or more.

[0022] The soft vinyl chloride resin composition comprising the above components is mixed by a mixer such as a super mixer, a Henschel mixer, a ribbon blender and the like, and then mixed with a Banbury mixer, a mixing roll, a single screw or a twin screw extruder. The mixture is kneaded by a machine and granulated. By arranging this in a mold with an inner layer serving as a core material injection-molded by a method and conditions generally used, and by injection-molding a soft vinyl chloride resin composition serving as a skin material, it is suitable as a vehicle interior Vehicle interior parts can be manufactured.

As the inner layer serving as the core material, crystalline thermoplastic resins such as nylon, polyacetal, polybutylene terephthalate, polyethylene terephthalate, and polypropylene, and those made of glass fiber, carbon fiber, Kepler fiber, talc, calcium carbonate, mica, Molded thermoplastic resin reinforced with hollow / solid glass beads, etc.
Further, those which have no problem even when they come into contact with a polyvinyl chloride resin composition, such as a thermosetting resin molded product and a metal processed product, are suitable.

[0024]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these descriptions. Each component of the formulation shown in Table 1 and Table 2
(Parts by weight) was charged into a 20-liter Henschel mixer and mixed, and the mixture was granulated with a 50 mm twin-screw extruder using a full flight screw having an L / D of 22 and a compression ratio of 3.0, and then sampled. (Pellet) was obtained. These samples were evaluated as follows, and the results are shown in Tables 1 and 2.

Manufacture of Armrest The inner core of the armrest injection-molded with polypropylene resin is inserted into the outer mold of the armrest. The sample (pellet) is molded by injecting a skin material at a resin temperature of 190 ° C. using a 180-ton general-purpose injection molding machine, and after cooling for a predetermined time, the molded body is removed from a mold.

(Specifications of components) ・ Vinyl chloride resin (referred to as PVC in the table): GR-800T (manufactured by Shin-Etsu Chemical Co., Ltd., trade name, average degree of polymerization 800, gel part 18)
%) ・ Vinyl chloride resin (referred to as PVC in the table): XEL-E (manufactured by Kaneka Chemical Co., Ltd., trade name, average polymerization degree 700, gel part 40%) ・ Vinyl chloride resin (PVC in the table) : TK-800 (Shin-Etsu Chemical Co., Ltd., trade name, average degree of polymerization 800, gel part 0%) ・ Vinyl chloride resin (in the table, PVC): TK-2500HS
(Shin-Etsu Chemical Co., Ltd., trade name, average polymerization degree 2450, gel part 0%) ・ Phthalate plasticizer: DINP (Shin Nippon Rika Co., trade name) ・ Polyester plasticizer: PN-1030 (Asahi Denka Industrial company,
・ Epoxylated soybean oil: O-130P (Asahi Denka Kogyo Co., Ltd., trade name) ・ Calcium carbonate: Whiteton SB (Bihoku Powder Chemical Co., Ltd., trade name) ・ Ba-Zn stabilizer: AC- 255 (manufactured by Asahi Denka Kogyo Co., Ltd.) Hindered amine light stabilizer (HALS-1 in the table)
: LA-62 (manufactured by Asahi Denka Kogyo Co., Ltd., liquid) ・ Hindered amine light stabilizer (HALS-2 in the table)
: LA-63 (Asahi Denka Kogyo Co., Ltd., trade name, powder) BLACK pigment: DAP-4710 (Dainichi Seika Co., Ltd., trade name) Methyl methacrylate copolymer (PMMA-1 in the table) )
: METABLEN P-530A (Mitsubishi Rayon Co., Ltd., trade name, weight average molecular weight 3.1 million) ・ Methyl methacrylate copolymer (PMMA-2 in the table)
: METABLEN P-531 (manufactured by Mitsubishi Rayon Co., Ltd., trade name, weight average molecular weight 4.7 million) ・ Methyl methacrylate copolymer (PMMA-3 in the table)
: METABLEN P-501A (Mitsubishi Rayon Co., Ltd., trade name, weight average molecular weight 800,000)

(Specification of Test Method) Moldability (Fluidity) In the manufacture of the above armrest, the moldability (fluidity) when the skin material was injection-molded was evaluated according to the following evaluation criteria, and the results were tabulated. 1 and Table 2. :: Can be molded without any problem. Δ: Molding can be performed with almost no problem. ×: It is difficult to produce a product having no problem. -Matting: The surface of the armrest created above was measured with a gloss meter, and the results are shown in Tables 1 and 2. In addition, as a standard of high-quality matte, a gloss of 5.0 or less was set as a target value.・ Product appearance Visually observe the surface of the armrest created above,
The flow mark phenomenon (the gloss unevenness of the tiger pattern occurs on the product surface) was represented by the following evaluation criteria. :: No flow mark was generated. Δ: Almost inconspicuous, but slightly occurred. ×: Flow mark has occurred. -Weather resistance test A sample (30 x 30 mm) was collected from the armrest created above and subjected to 40C at 83 ° C using an ultraviolet carbon fade meter.
The stickiness of the surface when irradiated for 0 hours was observed and evaluated according to the following criteria. (Evaluation criteria) ○: No bleed-out at all. Δ: Bleed out slightly. ×: Bleed out.

[0028]

【table 1】

[0029]

[Table 2]

[0030]

According to the present invention, it is possible to obtain interior parts for vehicles such as automobiles having excellent matte sensation, weather resistance and moldability.

Claims (2)

[Claims] Claims: 1. In an injection molded vehicle interior part,
A soft vinyl chloride-based resin composition serving as a skin material is based on 100 parts by weight of a partially cross-linked polyvinyl chloride-based resin, with a plasticizer of 20 to 200 parts by weight and a methyl methacrylate-based resin having a weight average molecular weight of 3,000,000 or more. An interior material for vehicles having excellent matting properties, comprising 1 to 30 parts by weight of a polymer and 0.05 to 3 parts by weight of a hindered amine light stabilizer. 2. The vehicle interior material having excellent mattability according to claim 1, wherein the partially crosslinked polyvinyl chloride resin has a degree of partial crosslinkage of 15 to 50% by weight.