JP3284106B2 - Composite skin, molded article, and thermoplastic elastomer composition for slash molding used therein - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a composite skin, a molded product,
And relates to the thermoplastic elastomer composition for slush molding used for it, in particular, regardless of the number of molding, the thermoplastic elastomer composition for slush molding to maintain powder fluidity, and also leave the composite skin and molded body Also, the present invention relates to a composite skin and a form that prevents adhesion of the oligomer component contained in the inner layer, the process oil, the stabilizer, the catalyst, and the like to the urethane foam that forms a foamed layer by preventing surface migration.

[0002]

2. Description of the Related Art As a powder molding method using a soft powder material, a powder slash molding method using a soft vinyl chloride resin powder is used for an instrument panel, a console box,
Widely used for the skin of car interior parts such as door trim. This is a soft touch, and can be provided with leather grain and stitches, and has good design properties such as a large degree of freedom in design.

[0003] Unlike other molding methods such as injection molding and compression molding, this molding method does not apply a shaping pressure. Therefore, in order to uniformly adhere a powder material to a mold having a complicated shape at the time of molding, powder molding is performed. In some cases, the powder has excellent fluidity, so that the powder attached to the mold melts and flows even under no pressure to form a film. In addition, it was necessary that the skin formed by cooling the mold could be released more easily than the mold.

As one method for improving this, Japanese Patent Application Laid-Open No. Hei 7-82433 discloses that a polypropylene resin and a specific styrene-based thermoplastic elastomer have a weight ratio of 70/3.
It has been proposed to pulverize and use a mixture of 0 to 30/70. Here, the styrene-based thermoplastic elastomer contains styrene having a styrene content of 20% by weight or less.
An ethylene butylene / styrene block copolymer, a styrene / ethylene propylene / styrene block copolymer having a styrene content of not more than 20% by weight, and a styrene content of 20
It is selected from a hydrogenated styrene-butadiene random copolymer rubber of not more than weight%, and has a good compatibility with a polypropylene resin and is a composition suitable for powder molding.

[0005]

In this composition, when the polypropylene resin and the hydrogenated styrene-butadiene random copolymer rubber are mixed, the hydrogenated styrene-butadiene random copolymer rubber is finely dispersed in the polypropylene resin. Suitable for skin material with little decrease. However, when used for the inner layer of a composite skin consisting of an outer layer and an inner layer, the hydrogenated styrene-butadiene random copolymer rubber has poor oil-absorbing ability. And had the disadvantage of having stickiness.

In particular, a transparent coating film is formed to reinforce the surface of the outer layer of the composite epidermis, and after heat treatment, with time, the above oligomer components contained in the inner layer,
There is a drawback that process oil, stabilizers, catalysts, and the like are easily transferred to the surface, and that adhesion to urethane foam is hindered. In addition, since the thermoplastic elastomer composition powder forming the inner layer is in an atmosphere at room temperature or higher during slush molding, the oligomer component, process oil, stabilizer, and catalyst in the composition migrate to the powder surface. In addition, the powder had tackiness, was easily blocked with the passage of days, and had poor powder flowability. When the outer skin is released from the mold, the releasability may be deteriorated, and the outer skin after the release may be deformed.

[0007] As described above, the skin obtained from the conventional thermoplastic elastomer composition has not been obtained in which both the mold releasability and the adhesion are improved, and either one of the required items is not satisfied. Met. Conventionally, a thermoplastic elastomer composition that satisfies the mold releasability has been improved, and a primer or an adhesive has been applied to the molded skin to increase the adhesiveness. However, many of the skins after the adhesive treatment have adhesiveness on the treated surface, cannot be stacked, and occupy a considerable space when storing the skin.

The present invention has been made to solve the above problems, and it is possible to leave a thermoplastic elastomer composition for slush molding, which maintains powder fluidity, a composite skin or a molded product, regardless of the number of moldings. The purpose of the present invention is to provide a composite skin and a molded product that maintain the adhesiveness to urethane foam that forms a foamed layer by preventing surface migration of process oils, stabilizers, catalysts, etc., including oligomer components contained in the inner layer. .

[0009]

According to the first aspect of the present invention, in a composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, at least a polypropylene resin and hydrogenated styrene-butadiene random are used as the outer layer. A layer obtained by slush molding a powder of a thermoplastic elastomer composition comprising a copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and an internal release agent, and an inner layer having at least an elastomer having excellent oil absorbing ability and active hydrogen. And a composite skin to which an adhesive layer comprising a powder of an adhesive thermoplastic elastomer composition containing an olefin-based polymer having the following formula (I) and a catalyst for promoting the reaction of isocyanate is adhered. The composite skin is produced by continuous slash molding of at least two layers consisting of an outer layer and an inner layer. The outer layer imparts excellent mold release properties, while the inner layer has excellent adhesiveness.

According to the invention of claim 2 of the present application, in the composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, the outer layer comprises at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, A layer obtained by slush-molding a thermoplastic elastomer composition powder comprising an elastomer having an excellent oil absorbing ability and an internal mold release agent, and further, at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an oil absorbing layer in the inner layer. For bonding comprising a thermoplastic elastomer composition powder (1) containing an elastomer having excellent performance, an elastomer having at least excellent oil absorbing ability, an olefin polymer having active hydrogen, and a catalyst for accelerating the reaction of isocyanate. Plastic elastomer There a mixed powder of powder of over composition (2) to the composite skin having a slush molding to the adhesive layer,
As in the first aspect of the invention, the outer layer imparts excellent mold release characteristics, while the inner layer has excellent adhesion.

In the invention according to claim 3 of the present application, the mixing weight ratio of the thermoplastic elastomer composition powder (1) and the bonding thermoplastic elastomer composition powder (2) in the inner layer is 1: 5 to 5: It is on the composite epidermis that becomes 1.

[0012] In the invention according to claim 4 of the present application, the elastomer having an excellent oil-absorbing ability is a composite skin comprising an ethylene-octene copolymer.

According to a fifth aspect of the present invention, there is provided a molded article with a composite skin comprising a laminate in which a foam layer is interposed between a composite skin composed of an outer layer and an inner layer and a core material composed of a synthetic resin. The outer layer is at least a polypropylene resin as an outer layer, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having an excellent oil-absorbing ability, and a layer obtained by slush molding a powder of a thermoplastic elastomer composition comprising an internal release agent, Further, an adhesive layer formed by slush molding a powder of an adhesive thermoplastic elastomer composition containing at least an elastomer having excellent oil absorption ability, an olefin polymer having active hydrogen, and a catalyst for promoting the reaction of isocyanate was attached to the inner layer. In a molded article with a composite skin using a skin.

According to a sixth aspect of the present invention, there is provided a molded article with a composite skin comprising a laminate in which a foam layer is interposed between a composite skin composed of an outer layer and an inner layer and a core material composed of a synthetic resin. The outer layer is at least a polypropylene resin as an outer layer, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and a layer obtained by slush molding a thermoplastic elastomer composition powder comprising an internal mold release agent, and A thermoplastic elastomer composition powder (1) containing at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an elastomer having excellent oil absorbing ability in its inner layer, and an elastomer having at least excellent oil absorbing ability, An olefin polymer having hydrogen,
Further, there is provided a molded article with a composite skin using a skin to which an adhesive layer is adhered by slush molding a mixed powder with a compound (2) containing a catalyst for promoting the reaction of isocyanate.

The invention according to claim 7 of the present application resides in a molded article with a composite skin, wherein the foamed layer is a polyurethane foam.

The invention according to claim 8 of the present application resides in a molded article with a composite skin, wherein the core material is an olefin resin.

According to the invention of claim 9 of the present application, there is provided a molded article with a composite skin, wherein the elastomer having excellent oil absorbing ability is an ethylene-octene copolymer.

In a tenth aspect of the present invention, in the composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, the outer layer comprises at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, Slush molding of a thermoplastic elastomer composition powder composed of an elastomer having excellent oil absorbing ability and an internal mold release agent, and further forming at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an oil absorbing ability as an inner layer. A composite skin obtained by slush molding a powder containing an excellent elastomer, an olefin polymer having active hydrogen, and a catalyst for accelerating the reaction of isocyanate.
The composite skin is produced by continuous slash molding of at least two layers consisting of an outer layer and an inner layer. The outer layer imparts excellent mold release properties, while the inner layer has excellent adhesiveness.

According to the eleventh aspect of the present invention, in the composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, Slush molding of a thermoplastic elastomer composition powder comprising an elastomer having excellent oil absorbing ability and an internal release agent, and further forming at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber as an inner layer, a process oil, and an oil absorbing ability A thermoplastic elastomer composition powder (1) containing an elastomer having an excellent elastomer, at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having an excellent oil-absorbing ability,
The composite skin obtained by slush molding a powder mixture of an olefin polymer having active hydrogen and a powder of an adhesive thermoplastic elastomer composition (2) containing a catalyst for accelerating the reaction of isocyanate. As in the present invention, the outer layer imparts excellent mold release properties, while the inner layer has excellent adhesion.

According to the invention of claim 12 of the present application, there is provided a composite skin to which an internal mold release agent is further added as an inner layer, wherein the composite skin is produced by slush molding in which at least two layers consisting of an outer layer and an inner layer are continuously formed. The outer layer imparts excellent mold release properties to the mold, while the inner layer maintains good adhesion to the urethane foam, which becomes a foamed layer, even after annealing, for example, for surface coating, and the urethane remains after a number of days. The peel strength and peeling state with the foam are maintained, and the adhesiveness is excellent.

In the invention according to claim 13 of the present application, the mixing weight ratio of the thermoplastic elastomer composition powder (1) and the bonding thermoplastic elastomer composition powder (2) in the inner layer is 1: 5 to 5: It is on the composite epidermis that becomes 1.

According to the invention of claim 14 of the present application, there is provided a composite skin having a coating film formed on the surface of the outer layer.

According to the invention of claim 15 of the present application, the elastomer having excellent oil absorbing ability used for the outer layer and the inner layer is a composite skin comprising an ethylene-octene copolymer.

According to the invention of claim 16 of the present application, a composite comprising a laminate in which a foam layer is interposed between a composite skin composed of at least an outer layer and an inner layer obtained by powder slush molding and a core material composed of a synthetic resin. In the molded body with a skin, the composite skin is at least a polypropylene resin as an outer layer, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability,
Then, the powder of the thermoplastic elastomer composition comprising the internal release agent is subjected to slush molding, and further, as the inner layer, at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and active hydrogen. A molded article with a composite skin, which is a composite skin obtained by slush molding a powder of an adhesive thermoplastic elastomer composition containing an olefin-based polymer and a catalyst for accelerating the reaction of isocyanate. The composite skin is formed by continuously slash forming at least two layers consisting of an outer layer and an inner layer. The outer layer has excellent mold release properties, and the outer skin is less deformed even when it is released from the mold. The inner layer has excellent adhesiveness and is well bonded to the foam layer and the core material.

According to the invention of claim 17 of the present application, there is provided a molded article with a composite skin to which an internal release agent is further added as an inner layer, wherein the composite skin is formed by slash molding at least two layers consisting of an outer layer and an inner layer. , The outer layer has excellent mold release characteristics, the skin is less deformed even when it is released from the mold, while the inner layer is, for example, after annealing for surface coating treatment,
The adhesiveness with the urethane foam to be the foamed layer is maintained well, and the peel strength and the peeling state with the urethane foam are maintained even after a lapse of days, and the adhesiveness is excellent.

According to the invention of claim 18 of the present application, there is provided a molded article with a composite skin, wherein the foamed layer is a polyurethane foam.

According to the invention of claim 19 of the present application, there is provided a molded article with a composite skin, wherein the core material is an olefin resin.

According to the invention of claim 20 of the present application, there is provided a molded article with a composite skin having a coating film formed on the surface of the outer layer.

According to the invention of claim 21 of the present application, there is provided a molded article with a composite skin, wherein the elastomer having excellent oil-absorbing ability used for the outer layer and the inner layer is an ethylene-octene copolymer.

The invention according to claim 22 of the present application is a thermoplastic elastomer composition for slush molding used for an inner layer in a composite skin comprising at least an outer layer and an inner layer, wherein at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber A process oil, an elastomer having excellent oil absorption, an olefin polymer having active hydrogen, a catalyst for accelerating the reaction of isocyanate,
The slush molding thermoplastic elastomer composition, which is an internal mold release agent, prevents the migration of oligomer components, process oil, stabilizers, catalysts, and other components contained in the slush molding even after a lapse of time. It maintains excellent peel strength with urethane foam and has excellent adhesiveness.

According to the invention of claim 23 of the present application, there is provided a thermoplastic elastomer composition for slush molding, wherein the elastomer having excellent oil absorbing ability is an ethylene-octene copolymer.

[0032]

FIG. 1 is a perspective view of the entire outer appearance of an instrument panel for a vehicle, which is one of the molded bodies with a skin, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. A
It is a part enlarged view. According to this, the instrument panel 1 is divided into a software section 2 and a hardware section 3,
In the first embodiment, a composite skin 4 composed of an outer layer 4a and an inner layer 4b having a textured pattern is covered on the front surface, and a core material 5 made of synthetic resin is located on the rear surface. A foam layer 6 such as a polyurethane foam is provided between them. On the other hand, in the hard portion 3, the composite skin 4 composed of the two layers of the outer layer 4a and the inner layer 4b is in close contact with the core material 5.

The composite skin 4 is a composite skin composed of an outer layer 4a and an inner layer 4b. The outer layer 4a is composed of at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and an inner release. It is obtained by slush molding powder of a thermoplastic elastomer composition comprising a mold agent.

On the other hand, when the inner layer 4b is made of a powder of a thermoplastic elastomer composition containing at least three components of an elastomer having excellent oil absorbing ability, an olefin polymer having active hydrogen, and a catalyst for accelerating the reaction of isocyanate, Thermoplastic elastomer containing at least six components of polypropylene resin, hydrogenated styrene-butadiene random copolymer rubber, process oil, elastomer having excellent oil absorbing ability, olefin polymer having active hydrogen, and catalyst promoting reaction of isocyanate It is a slush molded powder of the composition. Of course, an internal release agent may be added to the thermoplastic elastomer composition containing the above six components.

The outer layer 4a contains an internal mold release agent, so that the releasability from the mold is improved. The inner layer 4b contains an adhesion improver and a thermoplastic polyurethane elastomer, so that the foam layer 6 and the core material 5 are formed. Adhesive strength with is improved.

Further, a coating film (not shown) made of urethane or acrylic urethane is formed on the surface of the outer layer 4a to reinforce the surface of the outer layer 4a and prevent external damage. It is desirable to use a surface treatment agent for firmly adhering the coating film to the outer layer 4a.

The polypropylene resin used for only the outer layer 4a or the outer layer 4a and the inner layer 4b of the composite epidermis 4 of the present invention may be any of a polypropylene homopolymer, a block of α-olefin or a random copolymer. -A block or random copolymer using ethylene as the olefin is preferred from the viewpoint of the flexibility of the molded article. Further, in order to use the powder slush molding without applying pressure, the melt flowability index of the polypropylene resin is 230 ° according to JIS K7210.
C, MFR (melt flow rate) measured under a load of 2.16 kgf must be 20 g / 10 min or more. The polypropylene resin is a polymer whose main chain is cut by heat or oxidation, and has a property different from that of polyethylene or the like which crosslinks and hardens. The main chain is cut by an organic peroxide, and the molecular weight is reduced.

The hydrogenated styrene-butadiene random copolymer rubber (H-SBR) used for only the outer layer 4a or the outer layer 4a and the inner layer 4b of the composite skin 4 of the present invention.
Is excellent in compatibility with the polypropylene resin, and becomes flexible when kneaded with the polypropylene resin, whereby a thermoplastic elastomer composition that is hardly bent or whitened can be obtained. The styrene content of the hydrogenated styrene-butadiene random copolymer rubber is preferably 30% by weight or less, and in order to obtain a highly flexible skin, 5 to 15% by weight is appropriate.

H-SBR is different from SEBS which is a block copolymer in that styrene-butadiene rubber in which styrene and butadiene are randomly copolymerized is hydrogenated. A typical example is the Dynalon series, a product made by Nippon Synthetic Rubber Co., Ltd.

The mixing amount of the polypropylene resin and H-SBR is 80/20 to 20/80 by weight.
When the amount of the polypropylene resin increases, the formed skin becomes hard, while when the amount decreases, the tensile strength decreases.

Further, by adding a process oil to only the outer layer 4a or the outer layer 4a and the inner layer 4b of the composite skin 4 of the present invention, it is absorbed by the elastomer component in the composition to lower the melt viscosity and reduce the hardness of the skin. It has the effect of lowering and giving flexibility. The above process oils are used for rubber and are classified into paraffinic, naphthenic, and aroma-based oils. Paraffin-based oils are preferred because of their compatibility with elastomer components. The addition amount is preferably 5 to 200 parts by weight based on 100 parts by weight of the elastomer having excellent oil absorbing ability. If it exceeds 200 parts by weight, the tensile properties are reduced, and if it is less than 5 parts by weight, the melt viscosity does not decrease and the skin becomes hard.

Outer layer 4a and inner layer 4b of composite epidermis 4 of the present invention
Elastomers with excellent oil-absorbing ability are compatible with polypropylene resin, and have the property of absorbing process oil and oligomer components in the composition.
Styrene block copolymer thermoplastic elastomer such as styrene / ethylene butylene / styrene block copolymer (SEBS) and styrene / ethylene propylene / styrene block copolymer (SEPS), olefin crystal / ethylene butylene / olefin crystal block copolymer (CEBC), ethylene propylene Rubber (EPR),
And there is an ethylene-octene copolymer (POE).

In particular, the POE is a polymer mainly composed of a metallocene compound, having one reactive site (single) per molecule and a polymer obtained by using a single-site catalyst having a homogeneous active species. It has a long-chain branched structure, a narrow molecular weight distribution, a uniform composition distribution, and a low content of low molecular weight oligomers and waxes. Therefore, when blended with a polypropylene resin, EPDM (ethylene / propylene / non-conjugated diene copolymer) has better fluid dispersibility and is more easily dispersed in the polypropylene resin than EPDM.
It becomes a material suitable for slush molding. In addition, the POE
Is different in molecular structure from a linear one polymerized by an ordinary Ziegler-Natta catalyst, for example, a general-purpose ethylene propylene rubber obtained by copolymerizing ethylene and propylene.

The above SEBS is obtained by hydrogenating styrene / butadiene / styrene block copolymer (SBS), and includes Clayton G series, a product of Ciel Chemical Co., Ltd., and Tuftec H series, a product of Asahi Kasei Corporation. No. In this SEBS, the strength increases as the styrene content increases, but the flexibility decreases. Also,
In the case of the SEBS, the styrene hard segments may be aggregated due to melting at the time of slush molding, and it may be difficult to obtain a smooth sheet-like molded body. Therefore, the styrene content is preferably 40% by weight or less.

SEPS is obtained by hydrogenating styrene / isoprene / styrene block copolymer (SIS).
Septon, a product made by Kuraray Co., is representative. SE
As in the case of BS, the styrene content is preferably 40% by weight or less because the flexibility decreases as the styrene content increases.

The above-mentioned elastomer having excellent oil absorbing ability is
Compared with H-SBR, the compatibility with the polypropylene resin is inferior, and when kneaded and added to the polypropylene resin, it is dispersed in a size of μm unit, so that the tensile properties tend to decrease. On the other hand, H-SB
When R and process oil are added, the oligomer component in the composition has surface transfer (bleed) due to the poor oil-absorbing ability of H-SBR and has tackiness, and is used for pulverization for powder slush molding. Since the elastomer powder thus obtained also has tackiness, it tends to be blocked, so that the powder fluidity and the surface of the mold lack mold release properties. However, when an elastomer having excellent oil absorbing ability is added to the polypropylene resin, H-SBR, and process oil, the oligomer component and the oil in the composition can be absorbed to prevent surface migration.

The amount of the elastomer having excellent oil absorbing ability is 20 to 250 parts by weight based on 100 parts by weight of H-SBR. If the amount is less than 20 parts by weight, the oligomer component and oil in the composition cannot be sufficiently absorbed, and
If the amount exceeds 0 parts by weight, the dispersion with the polypropylene resin becomes poor, and the tensile properties tend to decrease.

The internal release agent used for the outer layer 4a or both the outer layer 4a and the inner layer 4b of the composite epidermis 4 of the present invention is a silicone oil such as dimethylsiloxane, methylhydroxypolysiloxane or methylphenylpolysiloxane, a higher fatty acid, or a higher fatty acid. Examples include fatty acid amides and higher fatty acid salts. In the outer layer 4a, the amount of addition is 0.1 to
When the content is less than 0.1% by weight, a sufficient releasing effect cannot be obtained. On the other hand, when the content is more than 5.0% by weight, the adhesion to the inner layer is inhibited. In the inner layer 4b, the addition amount is preferably from 0.1 to 5.0% by weight, and if it is less than 0.1% by weight, the effect of suppressing the surface migration of the oligomer component of the composition, the process oil, the stabilizer, the catalyst, and the like is reduced. On the other hand, if it exceeds 5.0% by weight, the adhesion to urethane foam is impaired.

On the other hand, as the olefin polymer having active hydrogen used for the inner layer 4b of the composite skin 4 of the present invention,
Acid-modified polypropylene resin, hydroxyl-containing polypropylene resin, hydrolyzate of ethylene-vinyl acetate copolymer,
Terminal carboxyl group polybutadiene, terminal hydroxyl group polybutadiene, hydrogenated terminal carboxyl group polybutadiene, hydrogenated terminal hydroxyl group polybutadiene, acid-modified styrene / ethylene butylene / styrene block copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid Copolymers can be mentioned. In the examples, an OH-modified polyolefin is used. The addition amount is preferably 2 to 20% by weight, and if it is less than 2% by weight, the effect of improving the adhesiveness is small, while if it exceeds 20% by weight, the decrease in tensile strength becomes large.

Examples of the catalyst for promoting the reaction of isocyanate used in the inner layer 4b of the composite skin 4 include organotin compounds such as dibutyltin dilaurate and dibutyltin distearate, tetraalkylethylenediamine, N, N'-dialkylbenzylamine. Tertiary amine compounds, such as fatty acid salts such as cobalt naphthenate and zinc stearate, and alkali metal carboxylate. The amount of the catalyst to be added is 0.1 to 100 parts by weight of a thermoplastic elastomer composition comprising a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, an elastomer having excellent oil absorbing ability, and an olefin polymer having active hydrogen. When the amount is less than 0.01 part by weight, the adhesion to the foamed layer is small and the effect is poor.
Exceeding parts by weight has an adverse effect due to surface migration.

Outer layer 4a and inner layer 4b of composite epidermis 4 of the present invention
As the heat stabilizer that can be used for the above, those used for ordinary polyolefins can be used. Generally, phenol and a phosphorus-based antioxidant are used in combination, but are not particularly limited. As the light stabilizer, a hindered amine or benzotriazole type radical scavenger may be used. Organic and inorganic pigments suitable for ordinary olefins are used. Further, a lubricant such as a fatty acid metal salt and a filler such as calcium carbonate and talc are added as required.

In the present invention, the above-mentioned polypropylene resin,
Add organic peroxide to the blend of process oil, elastomer with excellent oil absorption and internal release agent, or blend of polypropylene resin, olefin polymer with active hydrogen, elastomer with excellent oil absorbency, process oil, etc. In addition, these are kneaded under heating, and the organic peroxide cuts the main chain of the polypropylene resin, lowering the molecular weight of the polypropylene resin and increasing the melt flowability, and the obtained thermoplastic elastomer There is an effect that the composition has high melt fluidity. Here, the organic peroxide is not used as a crosslinking agent. Further, in the thermoplastic elastomer composition obtained by kneading under heating, the organic peroxide is thermally decomposed and substantially not contained.

The organic peroxide is usually a rubber,
Diacyl peroxide used for crosslinking of resin,
Peroxyester, diallyl peroxide, di-t
-Butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2.5-dimethyl-2
.5-di (t-butylperoxy) -hexane-3,1
• 3-bis (t-butylperoxy-isopropyl) benzene, 1,1-di-butylperoxy-3,3,5-
Trimethylcyclohexane and the like, and those having a one-minute half-life by thermal decomposition of 150 to 250 ° C. are preferable.

In the process of kneading under heating at 120 to 250 ° C., the organic peroxide cuts the main chain of the polypropylene resin to reduce the molecular weight, thereby giving the thermoplastic elastomer composition a high melt fluidity. The amount of the organic peroxide to be added is 0.02 to 5.0% by weight in the thermoplastic elastomer composition. When the amount is less than 0.02% by weight, the decomposition ability to cut the main chain of the polypropylene resin is small, High melt fluidity cannot be imparted to the thermoplastic elastomer composition. On the other hand, if the content exceeds 5.0% by weight, the decomposition becomes excessive and the mechanical properties such as the tensile strength of the powder molded product are reduced.

The mixture of these compounds is obtained by mixing a predetermined mixture with V
Dry blended using a type blender, tumbler, Henschel mixer, etc., is supplied from a raw material supply hopper, and process oil is injected from a vent port,
The mixture is melt-kneaded and pelletized by a twin-screw extruder whose temperature is controlled in the range of 250 ° C. Needless to say, kneading can be performed twice in time.

H-SBR, which is an elastomer component, is kneaded with a kneader, a Banbury mixer or the like, which is an internal mixer.
After adding process oil to an elastomer having excellent oil absorption capacity and kneading the mixture, pelletizing the mixture, mixing the pellets and the polypropylene resin with an organic peroxide and other compounding agents, and adjusting the temperature to a range of 120 to 250 ° C. Pellets can also be formed by melt-kneading with a single-screw or twin-screw extruder whose temperature has been adjusted.

The melt flow rate (MFR), which is the melt viscosity of the obtained pellets, is 2 according to JIS K7210.
50 g / 10 min or more at 50 ° C. and a load of 0.325 kgf is preferable. If it is less than this, the melt fluidity of the composition tends to be low, and pinholes tend to occur in the skin.

The pellets obtained from the above blend are finely pulverized using an impact type fine pulverizer such as a turbo mill, a pin mill, a hammer mill or the like. At this time, it is usually frozen and pulverized using liquid nitrogen. Further, depending on the composition, the molten resin can be powderized by spraying or cooling with a spray or disk atomizer. The pulverized product is passed through a sieve having a particle size of at least 1,000 μm by means of a sieve or the like, and those having an average particle size of 100 to 800 μm are collected, and an organic or inorganic powdery improver is added thereto and mixed. And used for powder slush molding.

The composition used to form the inner layer 4b of the composite skin 4 includes at least a polypropylene resin,
SBR, a thermoplastic elastomer composition powder (1) containing a process oil and an elastomer having excellent oil absorption ability,
It may be a mixed powder of at least an elastomer having excellent oil absorbing ability, an olefin polymer having active hydrogen, and a powder (2) of a bonding thermoplastic elastomer composition containing a catalyst for promoting the reaction of isocyanate. . The pulverization of the thermoplastic elastomer composition is as described above, and the mixing weight ratio of the thermoplastic elastomer composition powder (1) and the bonding thermoplastic elastomer composition powder (2) is also 1:
5 to 5: 1. When the amount of the thermoplastic elastomer composition powder for adhesion (2) is small, sufficient adhesion cannot be obtained,
Conversely, when the amount of the powder (2) is large, the tensile strength as the skin decreases.

The mixture of these compounds used for the inner layer 4b of the composite skin 4 is made of a thermoplastic elastomer containing at least a polypropylene resin, H-SBR, a process oil, an elastomer having excellent oil absorption, and an internal mold release agent. Bonding heat containing the composition powder (1) and at least a polypropylene resin, H-SBR, process oil, an elastomer having excellent oil absorption, an olefin polymer having active hydrogen, and a catalyst for accelerating the reaction of isocyanate. It is a mixed powder of the thermoplastic elastomer composition powder (2), and the pulverization of the thermoplastic elastomer composition is as described above. The powder of the thermoplastic elastomer composition (1) and the thermoplastic elastomer composition for bonding are The mixing weight ratio with the powder (2) is also 1: 5 to 5: 1. When the amount of the thermoplastic elastomer composition powder for bonding (2) is small, a sufficient adhesive effect cannot be obtained. On the contrary, when the amount of the thermoplastic elastomer composition powder for bonding (2) is large, the tensile strength as a skin is high. Decrease. Of course, an internal release agent can be added to the powder (2) of the thermoplastic elastomer composition for bonding.

Next, slush molding is performed using the above-mentioned elastomer composition powder. In this molding, the composition is dropped mainly by gravity and poured into a mold heated to a melting point of the composition used for the outer layer 4a or higher, and after a certain time has elapsed, the mold is inverted and excess composition is collected in a collection box. The composition adheres as a layer to the mold surface, and melts over time to form an outer layer having a thickness of 0.3 to 1.0 mm. Subsequently, the composition to be used for the inner layer 4b is dropped onto the outer layer and put therein, and after a certain period of time, the mold is inverted, and the excess composition is collected in a collection box. The layer adhering to the outer layer 4a melts with the passage of time to form an inner layer having a thickness of 0.1 to 0.5 mm. Then, the mold is cooled to release the composite epidermis 4, and this is repeated.

The method of heating the mold is generally a method of circulating oil or putting it in a hot blast stove. Oil circulation is easy to adjust the mold temperature by pipe arrangement, but is heated only from the mold surface. On the other hand, when a hot blast stove is used, heating can be performed from both sides of the mold surface and the back surface of the molded product. It is necessary to consider the prescription and conditions so as not to cause oxidative deterioration.

The hot air system is effective when performing powder slush molding in multiple layers (2 or 3). That is, the first powder to be the outermost layer is slush-molded in a heated mold,
The powder is deposited a second time in a semi-molten state and, if necessary, slushed a third time, then heat melted. In this case, if the heating is performed only from the mold surface side, the heat transfer is insufficient, so that a hot blast stove method capable of heating from the back surface of the molded product is often used.

The composite skin 4 obtained by the above powder slush molding is mounted on one mold so that the outer layer 4a touches the mold surface. And the other mold is polypropylene, AB
A core material 5 made of a synthetic resin such as S and polystyrene is provided, and a foaming liquid such as polyurethane is cast between them to form a foamed layer 6 to form a molded body with a slash adult skin.

[0065]

Next, the present invention will be described in more detail with reference to specific examples.

Examples 1 to 5 and Comparative Examples 1 and 2 Table 1 (Examples 1 and 2 and Comparative Example 1) and Table 2
As shown in (Examples 3 to 5 and Comparative Example 2), a polypropylene resin (PP resin) and an elastomer (P
OE), an internal release agent, Ca stearate, and an organic peroxide, which are dry-blended by a tumbler, are supplied from a raw material supply hopper of a twin-screw extruder (PCM45, manufactured by Ikegai Iron & Steel Co., Ltd.), and the process oil is vented. Cylinder temperature 210 ° C, screw rotation speed 300 rpm while pouring
m, then dry-blended H-SBR, process oil, phenolic antioxidant, and phosphite antioxidant are supplied from a raw material supply hopper of the same twin screw extruder, and the process oil is vented. The mixture was kneaded under the same conditions while being injected from the mouth, and extruded into pellets. still,
The materials in parentheses for parts by weight in the table are those added for the second time. Then, pellets immersed in liquid nitrogen were put into a Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.) and pulverized to collect only a 1,000 μm sieve.

As the inner layer, kneading was performed twice with a twin screw extruder under the same conditions as the outer layer, extruded into pellets, and the pellets immersed in liquid nitrogen were subjected to turbo mill T250-4J.
(Turbo Kogyo Co., Ltd.) and pulverized to 1,000 μm
The powder obtained by collecting only the amount passed through the sieve was used. The materials in parentheses in the parts by weight in the table are those added for the second time.

Next, slush molding was performed using the powder for the outer layer. As a method of slush molding, a 150 mm × 150 mm × 3 mm plate with a leather grain pattern was heated to 250 ° C. in an oven, and about 800 g of the above powder was placed on the plate for about 10 seconds to adhere. Thereafter, except for the powder that did not adhere by melting, the resultant was heated in an oven adjusted to 300 ° C. for 60 seconds to form an outer layer having a thickness of 0.6 mm. About 800 g of the powder for the inner layer is placed on the outer layer for about 10 seconds to form a layer having a thickness of 0.2 mm.
Melt for about 60 seconds in an oven adjusted to 00 ° C,
Then take out of the oven and cool with water, about 0.8m thick
m was removed from the epidermis.

The surface of the outer layer was spray-coated with a surface treating agent Resoid LU-775SP manufactured by Dainichi Seika Kogyo Co., Ltd., and sprayed with a urethane-based transparent paint Resroid LU-2408.
And then dried and heated in an oven at 80 ° C. for 30 minutes. In the evaluation of adhesiveness using the skin, 300 × 20
After using a 340 × 200 × 12 mm iron plate having a recess of 0 × 8 mm as a mold and heating in a 40 ° C. oven,
The skin was placed on the bottom of the depression, about 100 g of a premixed semi-rigid urethane foam raw material solution was injected, immediately sealed with an aluminum plate, and heated in an oven at 40 ° C. for 4 minutes to obtain a skin and urethane foam laminate. This is 25mm width and 1 length
It was cut out to 50 mm and used as a sample for evaluation.

18 between the skin and the urethane foam layer
The 0 ° peel strength and the peeled state were evaluated at a tensile speed of 200 mm / sec. Peel strength is ◎ when exceeding 5 N / 25 mm, ○ in the range of 1 to 5 N / 25 mm, 1 N / 25 mm
In the case of less than, it was evaluated as ×. The peeling state was expressed by 100% in the case of cohesive failure of the entire urethane foam, and expressed by that% in the case of partial cohesive failure. In addition, the evaluation of the adhesiveness using the skin was also performed for each elapsed days after the surface coating treatment.

For the melt viscosity, pellets were measured according to JIS K7210.
The melt flow rate was measured at 230 ° C. under a load of 2.16 kgf. These results are shown in Table 1 (Examples 1 to 3).
2, Comparative Example 1) and Table 2 (Examples 3 to 5, Comparative Example 2). In the powder property test, a powder tester (manufactured by Hosokawa Micron Corporation) was used to measure the angle of repose of the powder composition to which the powder property improver was added and the powder composition after molding 20 or more sheets.

[0072]

[Table 1]

[0073]

[Table 2]

As a result, it can be seen that in Examples, the releasability of the skin from the mold was good, and the peel strength between the inner layer of the skin and the urethane foam was high. The inner layer to which the silicone oil-based internal release agent is added has good adhesion to the urethane foam even after annealing of the surface coating treatment, and the peel strength and the peeling state from the urethane foam are maintained even after a lapse of days.
Regarding the powder properties, it can be seen that the powder on the inner layer side to which the silicone oil-based internal release agent is added maintains the powder fluidity.

Examples 6 to 8 and Comparative Examples 3 and 4 As the outer layer, the composition shown in Table 3 was kneaded under the same conditions as in Examples 1 to 5, and extruded into pellets. And
Pellets immersed in liquid nitrogen are put into a Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.) and pulverized to 1,000 μm.
Only the fraction passed through the sieve was collected.

As shown in Table 3, the inner layer was kneaded once with a twin screw extruder under the same conditions as the outer layer, extruded and pelletized, and the pellets immersed in liquid nitrogen were subjected to turbo mill T250-4J (turbo mill). (Manufactured by Kogyo Co., Ltd.) and pulverized, and used was a powder obtained by collecting only a 1,000 μm sieve.

Next, slush molding was performed using the powder for the outer layer. As a slush molding method, an outer layer having a thickness of 0.6 mm was molded under the same conditions as in Examples 1 to 5. On this outer layer, about 800 g of powder for the inner layer was
To form a layer having a thickness of 0.2 mm,
The mixture was melted for about 60 seconds in an oven adjusted to ° C, then taken out of the oven and cooled with water, and the skin having a thickness of about 0.8 mm was removed.

The quality of the difficulty in removing the epidermis was judged by feeling. ○ is good and × is bad. In the evaluation of the adhesion, 340 × 2 having a dent of 300 × 200 × 8 mm
Using an iron plate of 00 × 12 mm as a mold, after heating in an oven at 40 ° C., place a skin on the bottom of the hollow, inject about 100 g of a pre-mixed semi-rigid urethane foam raw material liquid, immediately seal with an aluminum plate, and seal at 40 ° C. The resultant was heated in an oven C for 4 minutes to obtain a skin and a urethane foam laminate. This is width 2
The sample was cut into 5 mm and 150 mm in length to obtain a sample for evaluation.

18 between the skin and the urethane foam layer
The 0 ° peel strength and the peeled state were evaluated at a tensile speed of 200 mm / sec. Peel strength is ◎ when exceeding 5 N / 25 mm, ○ in the range of 1 to 5 N / 25 mm, 1 N / 25 mm
In the case of less than, it was evaluated as ×. In the peeling state, the case of cohesive failure of the entire urethane foam was evaluated as ○, the case of partial cohesive failure was evaluated as Δ, and the case of entire surface interface fracture was evaluated as ×. Melt viscosity was measured at 230 ° C and 2.16k according to JIS K7210.
The melt flow rate was measured under a load of gf. Table 3 also shows these results.

[0080]

[Table 3]

As a result, in the examples, it is found that the removability of the skin from the mold is good, and the peel strength between the inner layer of the skin and the urethane foam is high.

[0082]

As described above, in the invention described in each claim of the present application, the composite skin and the outer layer of the molded body have excellent mold release properties,
The composite skin has good releasability from the mold and little deformation.On the other hand, the inner layer has excellent adhesion and is well bonded to the foam layer, and by adding an internal mold release agent to the inner layer, the outer layer and the metal are removed. The mold releasability with the mold is much better, the peel strength between the inner layer and the urethane foam is good even after a certain number of days, and the thermoplastic elastomer composition for slush molding also maintains powder fluidity in the molding process. There is an effect that there is.

[Brief description of the drawings]

FIG. 1 is an overall external perspective view of an automotive instrument panel according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Instrument panel 2 Soft part 3 Hard part 4 Composite skin 4a Outer layer 4b Inner layer 5 Core material 6 Foam layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B29K 9:06 B29K 9:06 21:00 21:00 23:00 23:00 B29L 31:58 B29L 31:58 Examiner Shogo Oshima (56) References JP-A-11-192678 (JP, A) JP-A-7-173366 (JP, A) JP-A-10-81793 (JP, A) JP-A-7-96532 (JP, A) JP-A-5-221271 (JP, A) JP-A-8-224820 (JP, A) JP-A-61-162328 (JP, A) JP-A-10-182900 (JP, A) 30036 (JP, A) JP-A-11-92602 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/10 B29C 41/18 B29C 41/22 B32B 25/04 B32B 27/32

Claims (23)

(57) [Claims] 1. A composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, wherein the outer layer comprises at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and A layer obtained by slush molding a powder of a thermoplastic elastomer composition comprising an internal mold release agent, and a catalyst for accelerating the reaction of an elastomer having at least excellent oil absorbing ability, an olefin polymer having active hydrogen, and an isocyanate in the inner layer. A composite skin comprising an adhesive layer formed by slash-molding a powder of a thermoplastic elastomer composition for adhesion containing: 2. A composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, wherein the outer layer comprises at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and A layer obtained by slush-molding a thermoplastic elastomer composition powder comprising an internal mold release agent, and further containing at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an elastomer having excellent oil-absorbing ability in the inner layer. Powder of thermoplastic elastomer composition powder (1) and powder of thermoplastic elastomer composition for adhesion containing at least an elastomer excellent in oil absorption ability, an olefin polymer having active hydrogen, and a catalyst for promoting the reaction of isocyanate ( 2) Composite skin characterized in that a bonding layer mixed powder of the by slush molding. 3. The method according to claim 2, wherein the mixing weight ratio of the thermoplastic elastomer composition powder (1) and the bonding thermoplastic elastomer composition powder (2) in the inner layer is 1: 5 to 5: 1. Composite epidermis. 4. The composite skin according to claim 1, wherein the elastomer having excellent oil-absorbing ability is an ethylene-octene copolymer. 5. A molded article with a composite skin comprising a laminate in which a foam layer is interposed between a composite skin composed of an outer layer and an inner layer and a core material composed of a synthetic resin, wherein the composite skin comprises at least a polypropylene resin as an outer layer. A layer obtained by slush molding a powder of a thermoplastic elastomer composition comprising a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and an internal mold release agent, and an inner layer having at least excellent oil absorbing ability. Using an outer layer to which an adhesive layer formed by slush molding a powder of an adhesive thermoplastic elastomer composition containing an elastomer, an olefin polymer having active hydrogen, and a catalyst for promoting the reaction of isocyanate is used. Molded body with composite skin. 6. A molded article with a composite skin comprising a laminate in which a foam layer is interposed between a composite skin composed of an outer layer and an inner layer and a core material composed of a synthetic resin, wherein the composite skin comprises at least a polypropylene resin as an outer layer; A layer obtained by slush-molding a thermoplastic elastomer composition powder comprising a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil-absorbing ability, and an internal mold release agent; and further, at least a polypropylene resin, hydrogen Powder (1) of a thermoplastic elastomer composition containing an added styrene-butadiene random copolymer rubber, a process oil, and an elastomer having excellent oil absorption, an elastomer having at least excellent oil absorption, an olefin polymer having active hydrogen, and Including a catalyst that promotes the reaction of isocyanate Powder (2) a composite skin-integrated molded article which is characterized in that mixed powder was slush molding using a skin adhering adhesive layer of the adhesive thermoplastic elastomer composition. 7. The molded article with a composite skin according to claim 5, wherein the foamed layer is a polyurethane foam. 8. The core material is an olefin resin.
Or a molded article with a composite skin according to 6. 9. The molded article with a composite skin according to claim 5, wherein the elastomer having excellent oil absorbing ability is an ethylene / octene copolymer. 10. A composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, wherein the outer layer comprises at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer excellent in oil absorption, and Slush molding of a thermoplastic elastomer composition powder comprising an internal release agent, and further having at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and active hydrogen as its inner layer. A composite skin obtained by slush molding a powder of an adhesive thermoplastic elastomer composition containing an olefin-based polymer and a catalyst for promoting the reaction of isocyanate. 11. A composite skin comprising at least an outer layer and an inner layer obtained by powder slush molding, wherein at least the outer layer is a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbing ability, and Slush molding of a thermoplastic elastomer composition powder comprising an internal mold release agent, and a thermoplastic resin containing at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an elastomer having excellent oil absorbing ability as an inner layer thereof Elastomer composition powder (1), at least polypropylene resin, hydrogenated styrene-butadiene random copolymer rubber, process oil, elastomer excellent in oil absorption ability, olefin polymer having active hydrogen, and Soshiane - adhesive thermoplastic elastomer composition comprising a catalyst which promotes the reaction of bets powder (2) a composite skin, wherein the mixed powder was slush molding the. 12. The composite epidermis according to claim 10, further comprising an internal release agent added to the inner layer. 13. The mixing weight ratio of the thermoplastic elastomer composition powder (1) and the bonding thermoplastic elastomer composition powder (2) in the inner layer is 1: 5 to 5: 1. The composite epidermis as described. 14. The composite skin according to claim 10, wherein a coating film is formed on a surface of the outer layer. 15. The composite skin according to claim 10, wherein the elastomer having excellent oil absorbing ability used for the outer layer and the inner layer is an ethylene-octene copolymer. 16. A molded article with a composite skin comprising a laminate obtained by interposing a foamed layer between a composite skin composed of at least an outer layer and an inner layer obtained by powder slush molding and a core material composed of a synthetic resin. The outer layer is slush-molded as a powder of a thermoplastic elastomer composition composed of at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, an elastomer having excellent oil absorbency, and an internal mold release agent as an outer layer. Thermoplastic elastomer for adhesion containing at least polypropylene resin, hydrogenated styrene-butadiene random copolymer rubber, process oil, elastomer having excellent oil absorption ability, olefin polymer having active hydrogen, and catalyst for promoting the reaction of isocyanate Slurry the powder of the composition Composite skin-integrated molded article which is a composite skin obtained by shoe molding. 17. The molded article with a composite skin according to claim 16, further comprising an internal release agent added to the inner layer. 18. The molded article with a composite skin according to claim 16, wherein the foamed layer is a polyurethane foam. 19. The molded article with a composite skin according to claim 16, wherein the core material is an olefin-based resin. 20. The molded article with a composite skin according to claim 16, 17, 18 or 19, wherein a coating film is formed on the surface of the outer layer. 21. The molded article with a composite skin according to claim 16, 17, 18, 19, or 20, wherein the elastomer having excellent oil absorbing ability used for the outer layer and the inner layer is an ethylene-octene copolymer. 22. A thermoplastic elastomer composition for slush molding used for an inner layer in a composite skin comprising at least an outer layer and an inner layer, which is excellent in at least a polypropylene resin, a hydrogenated styrene-butadiene random copolymer rubber, a process oil, and an oil absorbing ability. A thermoplastic elastomer composition for slush molding, comprising an elastomer, an olefin polymer having active hydrogen, a catalyst for accelerating the reaction of isocyanate, and an internal mold release agent. 23. The thermoplastic elastomer composition for slush molding according to claim 22, wherein the elastomer having excellent oil absorbing ability is an ethylene / octene copolymer having a long-chain branched structure.