JP2533147B2 - Thermoplastic elastomer molding - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a thermoplastic elastomer molded article used as an automobile interior sheet and the like, and more particularly to a thermoplastic elastomer molded article having excellent surface characteristics.

Technical Background of the Invention and Problems Thereof A soft polyvinyl chloride or a soft polyvinyl chloride is used as an automobile interior sheet conventionally used as a skin of an instrument panel pad or a door trim.
Blends with ABS resin have been mainly used. However, since such soft polyvinyl chloride contains a large amount of plasticizer, the window glass becomes cloudy due to volatilization of the plasticizer, and is deteriorated and discolored by ultraviolet rays of the sunlight incident on the window, or deteriorated and discolored by thermal decomposition. There was a problem that Moreover, there is a big problem that the soft polyvinyl chloride may be brittle and broken, especially in cold regions.

Therefore, in recent years, an interior sheet made of a polyolefin resin such as polypropylene has been used. However, moldings such as interior sheets made of polyolefin-based resin are liable to be scratched, and the surface gloss is too rich to be inferior in appearance, and the surface is rough and inferior in feel. There was a problem that it was easily invaded.

In order to pass such a problem, for example, JP-A-60
-197741, a sheet is molded from a thermoplastic elastomer composed of a polyolefin resin and a partially crosslinked ethylene / α-olefin copolymer rubber, and a saturated polyester resin, an acrylic ester resin, an isocyanate is formed on the surface of the sheet. A method for producing a sheet used for an automobile interior or the like, which is characterized by applying a reactive coating material containing a resin, has been proposed.

The sheet produced according to JP-A-60-197741 has surface characteristics such as surface abrasion resistance improved as compared with a sheet obtained without applying a reactive paint, but is still sufficient. There is a problem that it cannot be said to have excellent surface characteristics, and it has been desired to further improve the surface characteristics.

The present inventors have earnestly studied to obtain a thermoplastic elastomer molded product such as a leather-like automobile interior sheet having excellent surface properties, and after applying a primer having a specific composition to the surface of the thermoplastic elastomer molded product, It has been found that an elastomer having excellent surface properties can be obtained by applying a reactive paint such as

OBJECT OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, the surface is not easily scratched, and the appearance and feel are excellent, and the surface is attacked by a hydrocarbon solvent. It is an object of the present invention to provide a thermoplastic elastomer molding which is difficult to use as an automobile interior sheet or the like.

SUMMARY OF THE INVENTION A thermoplastic elastomer molded article according to the present invention is a molded article made of the following thermoplastic elastomer, which contains a partially cross-linked ethylene / α-olefin copolymer rubber and a polyolefin resin as required. A primer layer containing at least one compound selected from a saturated polyester and a chlorinated polyolefin is provided on the surface, and a saturated polyester, an acrylate resin, polyvinyl chloride and an isocyanate resin are selected on the primer layer. It is characterized in that a topcoat layer containing at least one kind of compound (provided that the topcoat layer contains at least an acrylic ester resin when the primer layer is composed only of saturated polyester) is provided.

Thermoplastic Elastomer: (a) Ethylene / α-olefin copolymer rubber 90 to
20 parts by weight, (b) 10 to 80 parts by weight of polyolefin resin (here, (a) + (b) is selected to be 100 parts by weight), and, if necessary, (c) peroxide non-crosslinking hydrocarbon type Rubber-like substance, (d) Partially crosslinked copolymer rubber composition obtained by dynamically heat treating a mixture consisting of 0 to 200 parts by weight of at least one component selected from mineral oil softeners in the presence of a crosslinking agent. (I) 100 to 30 parts by weight, and polyolefin resin (II) 0 to 70 parts by weight (where (I) + (II) is selected to be 100 parts by weight). Thermoplastic elastomer.

The thermoplastic elastomer molded article according to the present invention has a characteristic composition on the surface of a molded article made of a thermoplastic elastomer containing a partially cross-linked ethylene / α-olefin copolymer rubber and, if necessary, a polyolefin resin. Since it has a primer layer and a top coat layer of a specific composition, it has excellent surface characteristics such that the surface is not easily scratched, the appearance and feel are excellent, and the surface is not easily attacked by a hydrocarbon solvent. .

DETAILED DESCRIPTION OF THE INVENTION The thermoplastic elastomer molded article used as an automobile interior sheet or the like according to the present invention will be specifically described below.

The thermoplastic elastomer used in the present invention is
It contains a partially cross-linked product of ethylene / α-olefin copolymer rubber as an essential component and, if necessary, a polyolefin resin. Such a thermoplastic elastomer is typically (a) an ethylene / α-olefin copolymer rubber 90 to
20 parts by weight, (b) 10 to 80 parts by weight of polyolefin resin (where (a) + (b) is selected to be 100 parts by weight) and, if necessary, (c) non-crosslinking peroxide type hydrocarbon rubber A substance, (d) a mixture of at least one component selected from mineral oil-based softening agents, 0 to 200 parts by weight (preferably 0 to 100 parts by weight), which is dynamically heat treated in the presence of a crosslinking agent. 100 to 30 parts by weight of the partially crosslinked copolymer rubber composition (I) and 0 to 70 parts by weight of the polyolefin resin (II) (where (I) + (II) is selected to be 100 parts by weight). It is preferably formed from a composition consisting of In the present invention, these thermoplastic elastomers used are
More specifically, the following compositions can be exemplified.

(1) (a) A mixture of 90 to 20 parts by weight of an ethylene / α-olefin copolymer rubber and 10 to 80 parts by weight of a polyolefin resin (I), or 100 parts by weight of this mixture, and (c) a non-crosslinked peroxide. Type hydrocarbon type rubbery substance and / or (d) mineral oil softener 0 to 200 parts by weight, preferably 3 to 100 parts by weight, more preferably 5 to 100 parts by weight of the mixture (II) mixed with the presence of a crosslinking agent. Thermoplastic elastomer composition (ie, partially crosslinked copolymer rubber composition (I)) which is dynamically heat-treated under the following conditions (that is, partially crosslinked copolymer rubber composition (I)) (2) Thermoplastic comprising the above partially crosslinked copolymer rubber (I) An additional 700 per 100 parts by weight of the elastomer composition
A thermoplastic elastomer composition obtained by mixing a polyolefin resin (II) in a ratio of up to 3 parts by weight (about 233 parts by weight).

In the present invention, when an uncrosslinked elastomer composition is used instead of the partially crosslinked thermoplastic elastomer, it is not preferable because the resulting polymer composition has reduced tensile properties, heat resistance and oil resistance.

The ethylene / α-olefin copolymer (a), which is a raw material of the thermoplastic elastomer, includes, for example, ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene ternary or multicomponent copolymer rubber, ethylene-butadiene. Copolymer rubbers, ethylene-1-butene copolymer rubbers, ethylene-1-butene-non-conjugated diene multipolymers, etc., containing ethylene and an α-olefin having 3 to 14 carbon atoms as main components It is a crystalline copolymer rubber or a mixture thereof. Among them, ethylene-propylene copolymer rubber and ethylene-propylene-nonconjugated diene terpolymer rubber are preferred.

Here, the non-conjugated diene means dicyclopentanediene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, 5-ethylidene-2-norbornene and the like, among which dicyclopentadiene and 1,5-
A copolymer containing ethylidene-2-norbornene as a third component is preferable.

Mooney viscosity of these binary or multipolymers [WL _{1 + 4}
(100 ° C.)] is usually 10 to 180, preferably 40 to 140, and its iodine value (degree of unsaturation) is preferably 16 or less.

The amount of each composition unit contained in these copolymer rubbers is such that ethylene unit / α-in the 1-olefin part.
Olefin units 50/50 to 92/8, preferably 70/30 to 85/1
The ratio is 5 (molar ratio), and the ratio of 1-olefin (ethylene + α-olefin) unit / non-conjugated diene unit (in the case of a ternary or multi-component copolymer) is usually 100/0 to 90/10, preferably 98/2. ˜90 / 10, more preferably 97/3 to 94/6 (molar ratio).

The polyolefin resin (b) to be mixed with the ethylene / α-olefin copolymer rubber at the time of dynamic heat treatment includes ethylene, propylene, butene-1, hexene-
Homopolymers of 1-olefins such as 1,4-methyl-1-pentene, copolymers of two or more thereof, or copolymers of α-olefins and 15% by mole or less of other polymerizable monomers For example, ethylene-vinyl acetate copolymer, ethylene-
Acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer and the like, which are resinous polymeric substances The following are listed. Of these, the melt index (ASTM-D-1238
-65T) is 0.1 to 50g / 10mm, especially 5 to 20g / 10mm, and X
A polyolefin resin having a crystallinity of 40% or more determined by a linear diffraction measurement method is preferably used.

Among these, preferred polyolefin resin (b) is a peroxide-decomposable polyolefin resin having a melt index of 0.1 to 50 g / 10 mm and a crystallinity of 40% or more (thermolysis by mixing with peroxide and kneading under heating). To reduce the molecular weight and increase the fluidity of the resin), specifically isotactic polypropylene, or a copolymer of propylene and 15 mol% or less of another α-olefin, such as propylene- Ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-
4-metal-1-pentene copolymer can be exemplified.

As the polyolefin resin (b), the above-mentioned peroxide-decomposable polyolefin resin and peroxide-crosslinkable polyolefin resin (a polyolefin resin in which the fluidity of the resin has been lowered by crosslinking by mixing with peroxide and kneading under heating). For example, density 0.910 to 0.940
Low-, medium-, and high-density polyethylene with a weight ratio of 100 / 0-3
It is preferable to use a mixture of 0/70, especially 40/20 to 20/40, since it is excellent in thin-film moldability when a sheet-shaped molded product is produced. (A) 30 to 50 parts by weight of ethylene / α-olefin copolymer, (b) 20 to 40 parts by weight of polypropylene resin, 20 to 40 parts by weight of polyethylene resin and, if necessary, (c) peroxide. Physical properties of a sheet-like product obtained by partially cross-linking an ethylene / α-olefin-based copolymer rubber obtained by dynamically cross-linking a mixture containing a non-crosslinking hydrocarbon rubber-like substance and / or (d) mineral oil Is particularly preferable because it is excellent.

Next, in the preparation of the thermoplastic elastomer, (c) the peroxide non-crosslinked hydrocarbon-based rubber-like substance blended as necessary includes, for example, polyisobutylene, butyl rubber, propylene-ethylene copolymer having a propylene content of 70 mol% or more. It refers to a hydrocarbon-based rubbery substance which does not crosslink even when mixed with a peroxide such as coalesced rubber, propylene-1-butene copolymer rubber, atactic polypropylene and the like and kneaded under heating, and does not decrease in fluidity. Among them, polyisobutylene rubber, butyl rubber and propylene-1
-Butene copolymer rubber is most preferred.

(D) Mineral oil-based softeners usually reduce the intermolecular force of rubber when rolling rubber to facilitate the processing, and at the same time assist the dispersion of carbon black, white carbon, etc. A high-boiling petroleum fraction used to reduce the hardness of vulcanized rubber and increase its flexibility or elasticity, including paraffinic, naphthenic,
Alternatively, an aromatic type or the like is used.

In the preparation of the thermoplastic elastomer, it is not always necessary to incorporate these peroxide non-crosslinking hydrocarbon rubber-like substances (c) and / or mineral oil-based softeners (d), but the flow characteristics of the polymer composition, that is, molding In order to further improve the processability, the above-mentioned (c) and / or (d) is added to 100 parts by weight of the total amount of the ethylene-α-olefin copolymer rubber (a) and the polyolefin resin (b). It is desirable to add up to 200 parts by weight, preferably 3 to 100 parts by weight.

Further, in the present invention, the polyolefin resin (II) optionally mixed after the dynamic heat treatment is the same resin as the polyolefin resin (b) added during the dynamic heat treatment, that is, ethylene, propylene, butene-1. ,
A homopolymer of 1-olefin such as hexene-1,4-methyl-1-pentene, a copolymer of two or more kinds thereof, or a copolymer of α-olefin with 15 mol% or less of another polymerizable monomer. Polymers such as ethylene-vinyl acetate copolymers,
Ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer and the like, which are resinous A polymer material is used. The melt index of these polyolefin resins (II) (ASTM-D-1238-65T, 1
90 ° C, but 230 ° C for propylene-based polymers)
Is preferably 5 to 100, particularly preferably 10 to 50. When the polyolefin resin is added both during the dynamic heat treatment and after the heat treatment, the polyolefin resin (b) and the polyolefin resin (II) may be the same or different.

In order to prepare a partially crosslinked ethylene / α-olefin copolymer rubber which is one component of the thermoplastic elastomer in the present invention, 90 to 20 parts by weight of the ethylene / α-olefin copolymer rubber (a), Polyolefin resin (b) 10
To 80 parts by weight, and if necessary, about 0.0 to 100 parts by weight of a blend obtained by mixing 0 to 200 parts by weight of a peroxide non-crosslinked rubber (c) and / or a mineral oil-based softening agent (d).
1 to 3% by weight, preferably 0.05 to 2% by weight, more preferably 0.1 to 0.5% by weight of a cross-linking agent, and dynamically heat treated,
Partial crosslinking may be performed.

Dynamically heat-treating here means kneading in a molten state.

The kneading is preferably performed in a non-release type apparatus, and preferably in an inert gas atmosphere such as nitrogen or carbon dioxide gas. The temperature is usually 150 to 280 ° C, preferably 17
The temperature is 0 to 240 ° C., and the kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes.

Crosslinking agents used for partial crosslinking include organic peroxides, sulfur, phenolic vulcanizing agents, oximes,
Among them, polyamines and the like are used, and of these, organic peroxides and phenol-based vulcanizing agents are preferable from the viewpoint of physical properties of the thermoplastic elastomer obtained.

As the phenolic vulcanizing agent, an alkylphenol formaldehyde resin, a triazine-formaldehyde resin, and a melamine-formaldehyde resin can be used.

Further, as organic peroxides, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, 2,5
-Dimethyl-2,5-bis (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5- Trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, dibenzoyl peroxide, tert-butylperoxybenzoate and the like can be used. Among them, the bisperoxide compounds are preferable because of their low odor and high scorch stability, and 1,3-bis (tert-butylperoxyisopropyl) benzene is most preferable.

Further, in the partial crosslinking heat treatment, p-quinonedioxime,
By blending a crosslinking aid such as p, p'-dibenzoylquinonedioxime or a polyfunctional vinyl monomer such as divinylbenzene (DVB), diethylene glycol methacrylate, polyethylene diglycol methacrylate, a more uniform and gentle crosslinking reaction can be achieved. Since it can be realized, it is preferable to blend these crosslinking aids or polyfunctional vinyl monomers. Especially divinylbenzene (DV
B) is most preferable because a thermoplastic elastomer having a uniform cross-linking effect by heat treatment and having a good balance of fluidity and physical properties can be obtained.

Carbon black, clay, talc, calcium carbonate, heavy calcium carbonate,
Filler such as kaolin, diatomaceous earth, silica, alumina, asbestos, graphite, glass fiber or phenyl-α-naphthylamine, 2,6-ditert-butylphenol, tetrakis [methylene (3,5-di-tert)
-Butyl-4-hydroxyphenyl) propionate]
Such as an antioxidant, a weathering agent, a heat stabilizer, a flame retardant, an antistatic agent, and other additional components can be added.

These fillers or additives may be added at the stage of preparing the thermoplastic elastomer, or may be added at the time of preparing the thermoplastic elastomer after the preparation.

Partially crosslinked here means that the composition after crosslinking is crosslinked to such an extent that it does not lose its properties as a thermoplastic elastomer, and the gel content usually measured by the following method is 40. It means that it is more than%. Of these, those containing 45% or more of gel, particularly 70 to 99.5% are preferable.

Here, the measurement of the gel content is performed as follows.
Weigh about 100 mg of thermoplastic elastomer sample pellets,
Add this to 30cc cyclohexane in a closed container at 23 ° C.
After soaking for 48 hours, remove the sample and dry it for 72 hours or more until no weight change is observed. The weight of the dried residue minus any insoluble fillers, pigments, etc. other than the polymer component is defined as the corrected final weight (Y) after drying. On the other hand, from the weight of the sample pellet
Cyclohexane-soluble component other than α-olefin copolymer, for example mineral oil or plasticizer and cyclohexane-soluble rubber component and insoluble filler other than polyolefin resin,
The corrected initial weight (X) is obtained by subtracting the weight of the components such as the pigment.

From these values, the gel content is determined by the following equation.

The thermoplastic elastomer having the composition as described above,
According to a conventional method, the composition is supplied to a plastic processing machine such as an extrusion molding machine with a T-die and a calender molding machine, and molded into a desired shape such as a sheet. A pattern (diaphragm) may be provided on the surface of the sheet during molding of the thermoplastic elastomer. The molded product made of the thermoplastic elastomer molded in this manner has excellent physical properties such as weather resistance, heat resistance, cold resistance or light resistance.

In the thermoplastic elastomer composition according to the present invention,
The ratio of the above component (a) ethylene / α-olefin copolymer rubber to the component (b) polyolefin resin is
It can be determined by the DSC method or the infrared absorption analysis method. The ratio of the component (c) peroxide non-crosslinking hydrocarbon-based rubber-like substance to the component (d) mineral oil-based softening agent in the composition is determined by solvent extraction (Soxhlet extraction using acetone as a solvent) or infrared absorption. It can be determined by analytical methods.

In the present invention, a primer layer containing at least one compound selected from saturated polyester and chlorinated polyolefin is first formed on the surface of a molded article made of the above thermoplastic elastomer. To form a primer layer on the surface of a molded product, at least one compound selected from saturated polyester and chlorinated polyolefin is dissolved in an organic solvent, and the obtained coating liquid for forming a primer layer is molded by an ordinary method. It may be applied on the surface of the object.

As the saturated polyester resin used for forming the primer layer, polyethylene terephthalate, polybutylene terephthalate and derivatives thereof are used. As the chlorinated polyolefin resin, chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene / α-olefin copolymer and the like are used.

The coating liquid for forming a primer layer for forming a primer layer includes, in addition to the above-mentioned saturated polyester resin and chlorinated ethylene / α-olefin copolymer, if necessary,
It is also possible to include silicic acid anhydride (silica), pigments, matting agents and the like. Particularly, it is preferable to add silicic acid anhydride,
In this case, it is preferably added in an amount of up to 100% by weight based on the above polyester resin or chlorinated polyolefin.

As the organic solvent used for dissolving the saturated polyester resin and the chlorinated polyolefin resin, toluene, methyl ethyl ketone, ethyl acetate, methylene chloride, cyclohexanone and the like are used. Of these, a mixed solvent of toluene and methyl ethyl ketone is particularly preferably used. The solid content of the coating liquid for forming the primer layer is 2 to 50% by weight, preferably 10 to 15% by weight.

The film thickness of the primer layer provided on the surface of the molded article made of the thermoplastic elastomer is preferably about 10 to 20 μm.

When the primer layer as described above is formed on the thermoplastic elastomer molded article, the primer layer may be formed by applying the primer layer forming coating liquid in a plurality of times. Within the range specified by the invention, different coating compositions for forming a primer layer can be used.

Further, in the present invention, a printing ink layer (second layer) is provided between the primer layer (undercoat layer) and the topcoat layer.
It is also possible to provide a primer layer). In this case, the print ink layer contains polyvinyl chloride and pigment, polyester and pigment, or acrylic resin and pigment, toluene,
It can be formed by using a printing ink layer forming solution dissolved in a solvent such as methyl ethyl ketone.

A top layer containing at least one compound selected from saturated polyester, acrylic ester resin, polyvinyl chloride and isocyanate resin on the primer layer provided on the surface of the molded article made of the thermoplastic elastomer as described above. A coat layer is formed. However, when the primer layer contains only a saturated polyester among at least one compound selected from a saturated polyester and a chlorinated polyolefin, the top coat layer must contain at least an acrylate resin. .

To form the topcoat layer on the primer layer, at least one compound selected from saturated polyester, acrylic ester resin, polyvinyl chloride and isocyanate resin is dissolved in an organic solvent to form the obtained topcoat layer. The coating solution for use may be applied onto the primer layer according to a conventional method.

As the saturated polyester resin used to form the top coat layer, polyethylene terephthalate,
Polybutylene terephthalate and derivatives thereof are used. As the acrylic ester resin, polymethylmethacrylate, polyisobutylmethacrylate, poly-2-ethylhexylmethacrylate or the like is used. Further, as the isocyanate resin, polyhexamethylene diisocyanate, polyisophorone diisocyanate and the like are used.

When an acrylic ester resin is contained in the top coat layer, the surface of a molded article such as a sheet is less likely to be damaged.
Further, when an isocyanate resin is contained in the top coat layer, a top coat layer having excellent surface properties is obtained, and the isocyanate resin reacts with the primer layer or the thermoplastic elastomer to form a top coat layer and a primer layer. It can be strongly adhered to a molded article made of a thermoplastic elastomer. Furthermore, when a saturated polyester is contained in the top coat layer, a top coat layer having excellent surface properties can be obtained, and the binding property with an acrylate resin or an isocyanate resin can be maintained.

In the present invention, the top coat layer is preferably 80 to 10 parts by weight of an acrylic acid ester resin and 10 parts by weight of polyvinyl chloride.
-80 parts by weight with silicic acid anhydride (silica) 10-60 parts by weight, saturated polyester resin 95-5 parts by weight and isocyanate resin 5-95 parts by weight, acrylic ester resin 95-5 parts by weight A combination of 5 to 95 parts by weight of an isocyanate resin or a combination of 80 to 15 parts by weight of a saturated polyester resin, 15 to 85 parts by weight of an acrylic ester resin and 20 to 5 parts by weight of an isocyanate resin is used. Of these, a combination including all saturated polyester resins, acrylic ester resins and isocyanate resins is particularly preferable.

In the present invention, it is necessary to first form the primer layer and then the topcoat layer on the surface of the thermoplastic elastomer molded article. If the topcoat layer is formed directly on the molded product without forming the primer layer, a thermoplastic elastomer molded product having excellent surface abrasion resistance, scuffing resistance and tack resistance cannot be obtained.

The coating liquid for forming the topcoat layer for forming the topcoat layer contains, in addition to at least one compound selected from the above saturated polyester, acrylate resin, polyvinyl chloride and isocyanate resin, if necessary. In addition, silicic acid anhydride (silica), pigments, matting agents, etc. can be included. It is particularly preferred to add silicic acid anhydride, in which case silicic acid anhydride is added up to 100% by weight, preferably from 10 to 60% by weight, based on the resin.

As an organic solvent used for dissolving the resin for forming the top coat layer, methyl ethyl ketone, toluene, xylene, cyclohexanone, methylene chloride and the like are used. Of these, a mixed solvent of toluene and methyl ethyl ketone is particularly used for this microphone. The solid content concentration in the coating liquid for forming the top code layer is 5 to 50% by weight, preferably about 10 to 15% by weight.

The thickness of the topcoat layer thus provided on the surface of the primer layer is preferably 3 to 30 μm, more preferably 10 to 20 μm.

The coating liquid for forming the primer layer and the coating liquid for forming the top code layer may be applied on the surface of the thermoplastic elastomer molded product and the surface of the primer layer, respectively, by a conventional method as described above. However, for example, gravure roll coater, roll coater, knife coater,
A screen coater, a spray method and the like are employed.

Further, in the present invention, before forming the primer layer on the surface of the thermoplastic elastomer molded article, the surface may be subjected to corona discharge treatment.

In the present invention, the surface characteristics of the molded product can be remarkably improved by forming the primer layer and the top coat layer having the above-mentioned characteristic composition on the surface of the molded product of the thermoplastic elastomer. That is, the thermoplastic elastomer molding has excellent physical properties,
On the other hand, since it is a polyolefin type, it has problems such as weak scratching strength on the surface and being easily attacked by a hydrocarbon solvent. However, the primer layer (undercoat layer) and topcoat layer as described above are used. By forming, the abrasion resistance and scratch resistance of the molded product are improved, and the surface gloss and surface feel can be adjusted to the optimum state. Furthermore, the primer layer and the top coat layer as described above,
In addition to having excellent adhesion to the molded product, it also has excellent followability to the thermal deformation treatment of the molded product.

EFFECTS OF THE INVENTION The thermoplastic elastomer molded article according to the present invention has a surface of a molded article made of a thermoplastic elastomer containing a partially cross-linked ethylene / α-olefin copolymer rubber and a polyolefin resin as required. Since a primer layer of a specific composition and a top coat layer of a characteristic composition are provided, the surface is not easily scratched, and the appearance and feel are excellent, and the surface properties are not easily attacked by a hydrocarbon solvent. are doing.

The molded article according to the present invention, as leather, a sheet for interior materials of automobiles (doors, ceiling materials, handles, seat sheets, etc.), a cover for furniture such as chairs and sofas (skin),
Used for cases, bags, book covers, handbags, wallets, etc.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

In the following examples, the evaluation of the surface characteristics of the coating film comprising the primer layer and the top coat layer provided on the surface of the thermoplastic elastomer molded article was carried out as follows.

1.1. Coating adhesion Two days after application, the surface of the coating is sharpened with a sharp razor at 2 mm intervals.
Make one parallel wound and then make 11 parallel cuts at right angles to it. This cuts into 2mm squares, but 100 pieces are formed. Paste the scotch tape of the day van so as to cover all the 100 squares, and immediately vigorously peel off the scotch tape. (Hereinafter abbreviated as Goban eye peel test) Displayed in.

Example: No peeling 100/100 All peeling 0/100 1.2. Abrasion resistance test JIS L-083 Attached table using the Gakushin type friction tester specified in 4. (1) of JIS L-0849 After the sheet surface was abraded 500 gr × 200 times with Kanakin No. 3 specified in 1., the change in surface appearance is evaluated according to the scores A to E.

A. No change in appearance.

B. Slightly after cotton cloth.

C. Scratches.

D. Whiten.

E. Damage to the substrate.

1.3. Fatigue resistance test According to JIS L-1005 5.17 Friction strength, C. method (Scott method), 3 cm x 12 cm sheet pieces were sampled in a vertical or horizontal direction, and were opened at 2 cm intervals. It is fixed between chucks, and a pressure load of 1 kg (or 500 gr) is applied, and a distance of 4 cm is rubbed 1000 times back and forth.

Rating A. No change in appearance.

 B. Slightly whitened.

 C. Whitening or peeling.

1.4. Adhesion resistance test Performed in accordance with JIS K-6772 9.7 Non-adhesion test.

Face the surfaces of two 90mm x 60mm test pieces and
One side of the width of the test piece is sandwiched between two smooth glass plates of mm × 60 mm. Put a 2kg weight on this, 70 ℃ ± 2
After leaving it in an air incubator at ℃ for 24hrs, take it out, remove the weight, and let it cool to room temperature for 1 hour. When the two test pieces are gently peeled off, there is no abnormality such as damage on the sample surface. To find out.

Rating A. No damage, adhesion, etc.

 B. Slightly sticky.

 C. Damage.

1.5. Solvent resistance test When the surface is strongly wiped with a flannel cloth containing industrial gasoline, check whether there is any abnormality on the surface.

Rating A. No abnormality.

 B. Traces such as cloudiness are observed.

 C. Causes damage due to peeling and dissolution.

1.6. Scratch strength test A hole with a diameter of 6 mm is made in the center of a test piece with a diameter of 120 mm, and it is adhesively fixed to the turntable of a taper type scratch tester.

At the beginning of the test, place the blade of the cutter gently on the surface of the sample with a load of 100 g, turn on the switch and rotate the sample at 0.5 or 1.0 rpm, scratch to a length of at least 1.5 mm, and scratch the epidermis. Check for scratches.

Next, increase the load to 200 g, rotate the sample idly, see if the sample scratches again at another place, and if no scratch occurs, further increase the load to 300 g and 400 g and test. Then, visually determine the load when the epidermis of the sample is scratched or torn, and use it as the scratch strength.

1.7. Light resistance A test piece with a width of 70 mm and a length of 200 mm was attached to a Fed-O-meter, and the degree of discoloration of the skin material was visually observed after irradiation for 400 hours at a black panel temperature of 83 ± 3 ° C. The light resistance is evaluated by such a grade.

1.8. Moisture resistance A test piece of 100 mm x 100 mm is tested at 50 ° C ± 2 ° C and relative humidity of 95 ± 5
%, The surface condition of the test piece after 400 hours has passed is visually observed, and the humidity resistance is evaluated by the following grades.

1.9. Heat resistance A 100 mm x 100 mm test piece is placed in a thermostatic chamber adjusted to 100 ± 2 ° C, the surface condition of the test piece after 400 hours is visually inspected, and heat resistance is evaluated by the following grades.

Grade A. No change is observed.

B. There are slight changes, but they are hardly noticeable.

C. Obvious change, but less noticeable D. Somewhat noticeable change.

E. The changes are quite significant.

Example 1 Step (1) Production of Thermoplastic Elastomer A thermoplastic elastomer was produced in the following manner using the following components.

(Component A) Ethylene / propylene / ethylidene norbornene terpolymer rubber; ethylene unit / propylene unit (molar ratio): 78/22, iodine value 15, Mooney viscosity (ML
_{1 + 4} , 121 ° C) 61 (Component B) Isotactic polypropylene resin; melt index 13g / 10min (230 ° C) (Component C) Naphthenic process oil (Component D) 1,3-bis (tert-butylperoxy) Isopropyl) benzene 20% by weight, divinylbenzene 30% by weight and paraffinic mineral oil 50% by weight As described above, (A component) 55 parts by weight, (B component) 45 parts by weight and (C component) 30 parts by weight are added. After kneading at 180 ° C. for 5 minutes in a Banbury mixer under a nitrogen atmosphere, the obtained kneaded product was formed into a square pellet by a sheet cutter.

1 part by weight of (D component) was kneaded with 100 parts by weight of the square pellets using a Henschel mixer, and extruded at 220 ° C. in a nitrogen atmosphere with an extruder to produce a thermoplastic elastomer.

Step (2) Production of Sheet-Shaped Molded Product The thermoplastic elastomer produced as described above is
Using Toshiba 90mmφ T-die extruder, screw is full flight, L / D is 22, extrusion temperature is 220
° C, the T-die was a coat hanger die, and was extruded into a sheet having a thickness of 0.5 mm under the condition of a take-up speed of 5 m / min, and cooled with a cooling roll (roll temperature: 35 ° C) to form a sheet.

Step (3) Surface Treatment Step The above-mentioned sheet was coated once with a 120-mesh gravure roll with a coating solution for forming a first primer layer consisting of 10 parts by weight of chlorinated polypropylene, 2 parts by weight of silicic acid anhydride and 88 parts by weight of toluene. It was dried at 70 ° C for 20 seconds.

On top of this, a second primer layer forming coating liquid consisting of 8 parts by weight of polyvinyl chloride, 2 parts by weight of pigment and 90 parts by weight of methyl ethyl ketone was subjected to cloud pattern printing with a gravure roll,
It was dried again at 70 ° C. for 20 seconds.

Then, 5 parts by weight of polyvinyl chloride, 5 parts by weight of polyacrylate, 3 parts by weight of silicic anhydride, methyl ethyl ketone
A coating solution for forming a top coat layer consisting of 87 parts by weight was applied once with a 100 mesh gravure roll. This sheet was heated using a far-infrared heater until the surface temperature reached 180 ° C., and embossed.

 The physical properties of the obtained sheet-shaped molded product are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated except that the primer layer-forming coating solution was not applied in the step (3) of Example 1.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Example 2 Step (1) Production of thermoplastic elastomer The same procedure as in Step (1) of Example 1 was carried out.

Step (2) Production of sheet Low-density polyethylene [density 0.917 g / cm ³ melt index 6.5 g / 10 relative to 80 parts by weight of the above-mentioned thermoplastic elastomer
Min (190 ° C.)] 20 parts by weight were dry-blended, and the resulting blend was fed into a T-die extruder, in the same manner as in Example 1.

Process (3) Surface treatment process It carried out like the process (3) of Example 1.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Comparative Example 2 The procedure of Example 2 was repeated, except that the coating solution for forming the primer layer was not applied in the step (3) of Example 2.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Example 3 Step (1) Production of Thermoplastic Elastomer (C component) The same procedure as in Step (1) of Example 1 was performed except that naphthene-based process oil was not used.

Step (2) Production of sheet The same procedure as in Example 1 was performed.

Process (3) Surface treatment process The sheet surface was subjected to oxidation treatment by a solit state corona discharge treatment machine until the surface tension reached 45 dyne / cm.

A coating solution for forming a first primer layer consisting of 9 parts by weight of saturated polyester, 2 parts by weight of silicic acid anhydride, 1 part by weight of polyisocyanate, 50 parts by weight of toluene and 38 parts by weight of methyl ethyl ketone was applied to the sheet thus corona-treated. Apply once with 120 mesh gravure roll, 80 ℃
And dried for 15 seconds. Then 10 parts by weight of saturated polyester,
A cloud printing was performed with a gravure roll using a printing ink for writing, which was composed of 2 parts by weight of pigment, 50 parts by weight of toluene and 38 parts by weight of methyl ethyl ketone.

On top of this, a coating solution for forming a topcoat layer comprising 2 parts by weight of saturated polyester, 7 parts by weight of polyacrylic acid ester, 2 parts by weight of silicic acid anhydride, 1 part by weight of polyisocyanate, 50 parts by weight of toluene and 38 parts by weight of methyl ethyl ketone. It was applied with a 120 mesh gravure roll and placed in a thermostatic chamber at 30 ° C. for 24 hours for curing.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Comparative Example 3 The procedure of Example 3 was repeated, except that the primer layer-forming coating solution was not applied in step (3) of Example 3.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Example 4 Step (1) Production of Thermoplastic Elastomer A thermoplastic elastomer was produced in the following manner by using the following (E component).

(E component) Low density polyethylene with a melt index of 2g / 10 minutes (190 ° C) and a density of 0.920g / cm ³ .

(A component) 50 parts by weight, (B component) 25 parts by weight and (E
Ingredients) 25 parts by weight in a Banbury mixer under nitrogen atmosphere 18
After kneading at 0 ° C. for 5 minutes, square pellets were obtained with a sheet cutter. For 100 parts by weight of this square pellet, (D component)
1 part by weight was mixed with a Henschel mixer and extruded at 200 ° C. in a nitrogen atmosphere with an extruder to produce a thermoplastic elastomer.

Step (2) Manufacture of sheet The step (2) of Example 1 was performed.

Step (3) Surface Treatment Step The above-mentioned sheet was coated with a coating solution for primer layer consisting of 10 parts by weight of chlorinated polypropylene, 2 parts by weight of silicic acid and 88 parts by weight of toluene once with a 120 mesh gravure roll, and then at 60 ° C. And dried for 30 seconds.

Then, a coating solution for forming a topcoat layer consisting of 2 parts by weight of saturated polyester, 8 parts by weight of polyacrylic acid ester, 2 parts by weight of silicic acid anhydride, 50 parts by weight of toluene and 38 parts by weight of methyl ethyl ketone was formed on a 120-mesh gravure roll from above. It was applied twice.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Comparative Example 4 The procedure of Example 4 was repeated, except that the coating solution for forming the primer layer was not applied in the step (3) of Example 4.

 Table 1 shows the surface properties of the obtained sheet-shaped molded product.

Example 5 Example 5 was carried out in the same manner as in Example 1 except that the step (2) was carried out as follows.

Step (2) Manufacture of a sheet-shaped molded product The thermoplastic elastomer manufactured is subjected to a take-over calendering machine (18B) at 185 ° C and a take-up speed of 30 m / min.
A 0.5 mm thick sheet was formed.

Comparative Example 5 In the step (3) of Example 5, the same procedure as in Example 5 was carried out except that the coating liquid for forming the primer layer was not applied.

Table 1 shows the surface properties of the obtained sheet-shaped molded products.

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Claims (9)

(57) [Claims] 1. A saturated polyester and a chlorinated product are formed on the surface of a molded article made of the following thermoplastic elastomer, which contains a partially cross-linked ethylene / α-olephin-based copolymer rubber and, if necessary, a polyolefin-based resin. A primer layer containing at least one compound selected from polyolefins is provided, and a topcoat containing at least one compound selected from saturated polyester, acrylic ester resin, polyvinyl chloride and isocyanate resin is provided on this primer layer. Layer (provided that the topcoat layer contains at least an acrylate resin when the primer layer is composed of saturated polyester only); thermoplastic elastomer molded article; thermoplastic elastomer: (a) ethylene・ Α-olefin copolymer rubber 90〜
20 parts by weight, (b) 10 to 80 parts by weight of polyolefin resin (here, (a) + (b) is selected to be 100 parts by weight), and, if necessary, (c) peroxide non-crosslinking hydrocarbon type Rubber-like substance, (d) partially crosslinked copolymer rubber composition obtained by dynamically heat treating a mixture of 0 to 200 parts by weight of at least one component selected from mineral oil softeners in the presence of a crosslinking agent (I) 100 to 30 parts by weight, and polyolefin resin (II) 0 to 70 parts by weight (here (I)
+ (II) is selected to be 100 parts by weight), and a thermoplastic elastomer formed from the composition. 2. The primer layer contains chlorinated polyolefin and silicic acid anhydride.
The molded article according to item. 3. The molded product according to claim 1, wherein the saturated polyester is polyethylene terephthalate, polybutylene terephthalate or a derivative thereof. 4. The chlorinated polyolefin is chlorinated polyethylene, chlorinated polypropylene or chlorinated ethylene / α.
-The molded product according to claim 1, which is an olefin copolymer. 5. The molded product according to claim 1, wherein the film thickness of the primer layer is 10 to 20 μm. 6. The molded product according to claim 1, wherein the thickness of the top coat layer is 3 to 30 μm. 7. The molded product according to claim 1, wherein the top coat layer contains an acrylic acid ester, polyvinyl chloride and silicic acid anhydride. 8. The molded product according to claim 1, wherein a printing ink layer is provided between the primer layer (undercoat layer) and the topcoat layer. 9. The molded product according to claim 1, wherein the molded product is in the form of a sheet.