JP2001226542A - Thermoplastic elastomer composition for slash molding and composite skin using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition for slash molding which composition has a strong adhesivity to a urethane foam becoming a foam layer, low in deterioration with the lapse of time even in various molding conditions, has an excellent adhesiveness at a high temperature, and exhibits only a small reduction in mechanical property even if a large amount of an ethylene/octene copolymer as an elastomer component is added thereto, and to provide a composite skin using this composition. SOLUTION: This thermoplastic elastomer composition of slash molding is obtained by lending at least a polypropylene resin, a hydrogenated styrene/ butadiene rubber, an ethylene/octane copolymer, an olefin polymer having an active hydrogen, a catalyst promoting a reaction with an isocyanate, a plasticizer and an olefin-crystal/ethylenebutylene/olefin-crystal block copolymer as a compatibilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition for slush molding and a composite skin using the same. More specifically, the adhesiveness to urethane foam which is a foamed layer is strong even if the molding conditions are different. The present invention relates to a thermoplastic elastomer composition for slush molding, which exhibits little change with time and excellent adhesive strength at high temperatures, and a composite skin using the same.

[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. In particular, in the instrument panel, since a composite material of a core material made of a synthetic resin such as polypropylene, ABS, and polystyrene, a foam layer made of urethane foam, and a skin layer made of a soft vinyl chloride resin is used, the foam layer is soft. It has the characteristics of giving a feel, and being capable of providing a skin texture or stitch by powder molding, and having good design properties such as a large degree of freedom in design.

However, in recent years, vinyl chloride resins have tended to be shunned due to the problem of global environmental issues and the reduction of environmentally hazardous substances. There was an urgent need to develop a resin that would

Further, unlike the other molding methods such as injection molding and compression molding, the powder molding method used for molding the skin material does not apply a shaping pressure. In order to uniformly adhere to the mold, the powder fluidity may be excellent, and the powder adhered to the mold melts and flows even under no pressure to form a film. Has become. 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. 9-52990 discloses a method of pulverizing a thermoplastic elastomer composition comprising a polypropylene resin, a specific styrene thermoplastic elastomer and an ethylene / octene block copolymer. It has been proposed to use it. here,
A specific styrene-based thermoplastic elastomer is finely dispersed in polypropylene resin, and a plasticizer such as process oil added to improve the melt fluidity required for powder molding is an ethylene-octene block copolymer. By keeping the gloss after heat aging, the composition is an olefin-based thermoplastic elastomer composition suitable for powder molding.

[0006]

However, when such an olefin-based thermoplastic elastomer composition is used as a substitute for a conventional soft vinyl chloride resin for the skin of automobile interior parts, a difference in polarity between the foamed layer and the foamed layer results. There is a problem that the adhesiveness to the urethane foam is reduced. In order to solve this problem, the creation of a composite skin consisting of an outer layer having excellent mold release properties with a mold and an inner layer to which a catalyst for promoting the reaction with an olefin polymer or isocyanate having active hydrogen was added was devised. The adhesiveness of the inner layer depends on the production method at the factory scale, where the molding temperature and molding cycle pitch vary widely, and the time elapsed from the skin molding to the foaming process, etc., depending on the oligomer components and plastics contained in the thermoplastic elastomer composition. In some cases, the transfer of the agent or catalyst to the adhesive interface was promoted, and the adhesion to the urethane foam as the foamed layer was inhibited, and a sufficient effect could not be obtained.

Further, in the case of an instrument panel using a slash skin, the slash skin and the urethane foam are bonded not only at room temperature but also in summer, so that they do not delaminate even at a high temperature of about 120 ° C. Sex is also required.

The present invention has been made to solve the above problems. The adhesiveness to the urethane foam to be a foamed layer is strong even with a difference in molding conditions, the change with time is small, and the adhesive strength at high temperatures is excellent. It is an object of the present invention to provide a thermoplastic elastomer composition for slush molding and a composite skin which does not cause a decrease in mechanical properties even when a large amount of an ethylene-octene copolymer as an elastomer component is added.

[0009]

That is, in the invention of claim 1 of the present application, at least a reaction with a polypropylene resin, a hydrogenated styrene-butadiene rubber, an ethylene / octene copolymer, an olefin polymer having active hydrogen, and an isocyanate. The present invention is a thermoplastic elastomer composition for slush molding, comprising a catalyst, a plasticizer, and an olefin crystal / ethylene butylene / olefin crystal block copolymer as a compatibilizer. The above composition gives the melt fluidity necessary for slush molding, has a strong adhesiveness to urethane foam as a foamed layer even with a difference in molding conditions, has little change with time, and has excellent adhesive strength at high temperatures.

In the invention of claim 2 of the present application, the olefin crystal / ethylene butylene / olefin crystal block copolymer contained in the thermoplastic elastomer composition is a mixture of a polypropylene resin and an ethylene / octene copolymer. The slush molding thermoplastic elastomer composition is 5 to 20 parts by weight based on 100 parts by weight.

The invention according to claim 3 of the present application is a composite skin in which at least an outer layer and an inner layer are laminated, wherein the inner layer is at least a polypropylene resin, a hydrogenated styrene-butadiene rubber, an ethylene / octene copolymer, and an olefin having active hydrogen. Composite obtained by slush molding powder of thermoplastic elastomer composition containing olefin crystal, ethylene butylene, olefin crystal block copolymer as a compatibilizer, a catalyst for accelerating the reaction with an isocyanate polymer, isocyanate It is the epidermis.

In the invention according to claim 4 of the present application, the olefin crystal / ethylene butylene / olefin crystal block copolymer contained in the thermoplastic elastomer composition comprises:
The composite skin is 5 to 20 parts by weight based on 100 parts by weight of a mixture of a polypropylene resin and an ethylene / octene copolymer.

The invention according to claim 5 of the present application is a composite skin in which at least an outer layer and an inner layer are laminated, wherein the outer layer includes at least a polypropylene resin, a hydrogenated styrene-butadiene rubber, a plasticizer, an ethylene / α-olefin copolymer, It is a composite skin obtained by slush molding a powder of a thermoplastic elastomer composition containing an internal release agent and an organic peroxide.

The invention according to claim 6 of the present application is a composite skin wherein the ethylene / α-olefin copolymer contained in the thermoplastic elastomer composition is an ethylene / octene copolymer.

[0015]

FIG. 1 is a perspective view showing the entire appearance of an instrument panel for a vehicle, which is one of molded articles using the above-mentioned composite skin, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG.
FIG. 3 is an enlarged view of a portion A in FIG. 2. According to this, the instrument panel 1 is divided into a software part 2 and a hardware part 3,
In the soft part 2, a slush-molded skin 4 composed of two layers, an outer layer 4a and an inner layer 4b, having a textured pattern on the surface.
Is covered, and a core material 5 made of a synthetic resin is located on the back surface,
A foam layer 6 such as urethane foam is provided between the slush molded skin 4 and the core material 5. On the other hand, in the hard part 3, the slash-molded skin 4 composed of two layers, the outer layer 4a and the inner layer 4b, and the core material 5 are in close contact with each other.

The slush-molded skin 4 is a composite skin comprising an outer layer 4a and an inner layer 4b. The outer layer 4a is not particularly limited, but is formed by using an olefin-based thermoplastic elastomer (TPO) composition. Are similar, which is advantageous in terms of recycling. More preferably, JP-A-9-52 contains substantially the same components as the inner layer.
No. 990, a thermoplastic elastomer composition comprising a polypropylene resin, a hydrogenated styrene-butadiene rubber, and an ethylene / octene block copolymer to which a plasticizer, an organic peroxide and an internal mold release agent are added. The use of slag has the melt fluidity required for slush molding and also has excellent mold releasability.

A coating film (not shown) made of urethane or acrylic urethane is formed on the surface of the outer layer 4a, and the surface of the outer layer 4a can be reinforced to prevent external damage. Note that it is desirable to use a surface treatment agent to firmly adhere the coating film to the outer layer 4a.

On the other hand, the inner layer 4b is made of at least a polypropylene resin, a hydrogenated styrene butadiene rubber,
A thermoplastic elastomer composition containing an octene copolymer, an olefin polymer having active hydrogen, a catalyst for accelerating the reaction with isocyanate, a plasticizer, and an olefin crystal / ethylene butylene / olefin crystal block copolymer as a compatibilizer. It is slush molded.

Incidentally, this is an embodiment of the present invention, and the composite skin is not limited to the lamination of only the outer layer and the inner layer, but it is of course possible to laminate two or more layers.

Outer layer 4a of slush molded skin 4 of the present invention
And the polypropylene resin used for the inner layer 4b may be any of a polypropylene homopolymer, a block or a random copolymer with an α-olefin, and particularly, a block or a random copolymer using ethylene as the α-olefin is a molded product. It is preferable in terms of flexibility. Further, in order to use the powder slush molding without applying pressure, the melt flowability index of the polypropylene resin is 230 ° C. according to JIS K7210 and the load is 21.degree.
MFR (melt flow rate) measured at 18N is 20
g / 10 minutes 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 rubber (H-SBR) used for the outer layer 4a and the inner layer 4b of the slush molded skin 4 of the present invention has excellent compatibility with the polypropylene resin, and is soft when kneaded with the polypropylene resin. And a thermoplastic elastomer composition that is less likely to bend or whiten is obtained. The styrene content of the hydrogenated styrene-butadiene rubber is preferably 30% by weight or less, and 5 to 15% by weight is appropriate for obtaining a flexible skin.

H-SBR differs 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.

The ethylene / α-olefin copolymer used for the outer layer 4a of the slush molded skin 4 of the present invention is:
As the α-olefin, those having 3 to 8 carbon atoms such as propylene, butylene and octene are used. In particular, an ethylene-octene copolymer having 8 carbon atoms is preferable because it has a certain degree of compatibility with the polypropylene resin and has a property of absorbing the process oil and the oligomer component in the composition. The ethylene-octene copolymer is a catalyst mainly composed of a metallocene compound, and is obtained by using a single-site catalyst in which the number of reaction points (sites) is one (single) per molecule and the active species is also homogeneous in the site. It has a long-chain branched structure, narrow molecular weight distribution, uniform composition distribution, and low content of low molecular weight oligomers and waxes.
It is considered that the above elastomer has high oil absorbing ability and is easily compatible with an olefin polymer having active hydrogen acting as an adhesion improver. This addition amount is 10
30 to 250 parts by weight, preferably 30 parts by weight,
If the amount is less than 10 parts by weight, the probability of existence of the adhesion modifier at the adhesion interface decreases, and the oligomer component and the plasticizer in the composition cannot be sufficiently absorbed. If the adhesion exceeds 250 parts by weight, the matrix layer of the composition becomes an ethylene-octene copolymer, which softens at high temperatures, and tends to reduce the adhesion and the tensile properties.

The active hydrogen-containing olefin polymer used for the inner layer 4b of the slush molded skin 4 of the present invention includes acid-modified polypropylene resin, hydroxyl-containing polypropylene resin, hydrolyzate of ethylene / vinyl acetate copolymer, and terminal carboxyl group. Polybutadiene, terminal hydroxyl group polybutadiene, terminal carboxyl group polybutadiene hydrogenated product, terminal hydroxyl group polybutadiene hydrogenated product, acid-modified styrene / ethylene butylene / styrene block copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid copolymer And the like. Further, an olefin polymer having two or more active hydrogens can be added as needed. In the examples, a hydroxyl-modified polyolefin and an olefin-based polyol are 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.

The catalyst for promoting the reaction of isocyanate used in the inner layer 4b of the slush molded skin 4 of the present invention includes organic tin compounds such as dibutyltin dilaurate and dibutyltin distearate, tetraalkylethylenediamine, N, Examples include tertiary amine compounds such as N'-dialkylbenzylamine, fatty acid salts such as cobalt naphthenate and zinc stearate, and alkali metal carboxylate. The amount of the catalyst added is 0.01 to 2
If the content is less than 0.01% by weight, the adhesion to the foamed layer is small and the effect is poor, and if it exceeds 2% by weight, adverse effects are caused by migration to the bonding interface.

The addition of the plasticizer used in the outer layer 4a and the inner layer 4b of the slush-molded skin 4 of the present invention has the effect of lowering the melt viscosity of the composition, lowering the hardness of the skin, and imparting flexibility. . In particular, there are process oils, petroleum resins and natural resins used for rubber, and the process oils are classified into paraffinic, naphthenic and aroma-based, and paraffin-based is preferred due to compatibility with the elastomer component. A typical example is PW-380 manufactured by Idemitsu Kosan Co., Ltd. Petroleum resins are commonly used as tackifiers for rubber, diolefins and alicyclic petroleum resins by-produced in the cracking of petroleum, and natural resins include terpene resins from natural plant essential oils. Terpene-phenolic resins. Further, it is preferable to use a hydrogenated derivative in terms of heat resistance and compatibility. A typical example is the Clearon series manufactured by Yasuhara Chemical. The addition amount is preferably 3 to 25 parts by weight based on 100 parts by weight of the thermoplastic elastomer composition comprising the polypropylene resin, the hydrogenated styrene-butadiene rubber, the ethylene / octene copolymer, and the olefin polymer having active hydrogen. If the amount is less than 3 parts by weight, the melt viscosity does not decrease, the skin becomes hard and the moldability decreases, and if it exceeds 25 parts by weight, the transfer of the plasticizer component to the adhesive interface increases, impairing the adhesiveness with the foam layer, The tensile properties also decrease.

Further, an olefin crystal / ethylene butylene / olefin crystal (CEBC) is used for the inner layer 4b of the slush molded skin 4 of the present invention as a compatibilizer between polypropylene and an ethylene / octene copolymer. Olefin crystals, ethylene butylene and olefin crystals consist of EB blocks compatible with polypropylene and C blocks (crystalline blocks similar to polyethylene) compatible with ethylene polymers. Is mentioned. The amount added is preferably
It is 5 to 20 parts by weight based on 100 parts by weight of the mixture of polypropylene and ethylene / octene copolymer. If the amount is less than 5 parts by weight, the dispersibility of the ethylene / octene copolymer in propylene is low, so that the adhesiveness is not significantly improved. If the amount is more than 20 parts by weight, the tensile properties are reduced.

The internal release agent used for the outer layer 4a of the slush molded skin 4 of the present invention is dimethylsiloxane,
Examples include silicone oils such as methylhydroxypolysiloxane and methylphenylpolysiloxane, higher fatty acids, higher fatty acid amides and higher fatty acid salts. The addition amount is preferably 0.1 to 5.0% by weight, and if it is less than 0.1% by weight, a sufficient releasing effect cannot be obtained, while if it exceeds 5.0% by weight, the adhesion to the inner layer is inhibited. You.

The organic peroxide used for the outer layer 4a of the slush molded skin 4 of the present invention is usually 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;
Those having a half-life of 150 to 250 ° C. per minute are preferred.

The above organic peroxide is used at a temperature of 120 to 250 ° C.
In the process of kneading under heating, there is an effect that the main chain of the polypropylene resin is cut to reduce the molecular weight, and the thermoplastic elastomer composition has high melt fluidity. The addition amount is 0.02 to 5.0% by weight in the thermoplastic elastomer composition, and when the addition amount is less than 0.02% by weight, the decomposition ability of cutting the main chain of the polypropylene resin is small, and the thermoplastic elastomer composition Cannot be given high melt fluidity. 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.
Further, it is desirable not to add the inner layer 4b to the inner layer 4b because it affects the formation of an oligomer that inhibits adhesion to urethane foam.

The outer layer 4a and the inner layer 4b of the slush molded skin 4 of the present invention are added with, for example, a light stabilizer, a heat stabilizer, a lubricant such as a fatty acid metal salt, and a filler such as calcium carbonate and talc. Can also. As the light stabilizer, those used for ordinary polyolefins can be used. Generally, a phenol and a phosphorus-based antioxidant are used in combination, but are not particularly limited. As the light stabilizer, a hindered amine or benzotriazole-based one as a radical scavenger is used. Further, is added as needed. Organic and inorganic pigments suitable for ordinary olefins are used.

The mixture of these compounds is obtained by mixing a predetermined mixture with V
Dry blended using a mold blender, tumbler, Henschel mixer, etc., is supplied from a raw material supply hopper, and a catalyst for accelerating the reaction with a plasticizer (process oil) and isocyanate is injected from a vent port.
The mixture is melt-kneaded with a twin-screw extruder adjusted to a temperature of 50 ° C. to form pellets.

H-SBR which is an elastomer component is kneaded with a kneader or a Banbury mixer which is an internal mixer.
After adding a plasticizer to the ethylene-octene copolymer and kneading the resulting mixture to form a pellet, the pellet and the polypropylene resin are mixed with an organic peroxide and other compounding agents.
Pellets can also be formed by melt-kneading with a single-screw or twin-screw extruder whose temperature is controlled in the range of 0 to 250 ° C.

The melt flow rate (MFR), which is the melt viscosity of the obtained pellets, is 2 according to JIS K7210.
The load is preferably 20 g / 10 min or more at 30 ° C. and a load of 21.18 N. If it is less than this, the melt fluidity of the composition may be so small that it cannot be formed into a 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.

Next, slush molding is performed using the powder of the elastomer composition. 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 slash-molded skin 4, and this is repeated.

As a heating method of the mold, a method of circulating the oil or putting it into a hot blast stove is generally used. 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 (two or three). 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 slush molded skin 4 obtained by the above powder slush molding is mounted on one mold so that the outer layer 4a touches the mold surface. A core material 5 made of a synthetic resin such as polypropylene, ABS, or polystyrene is placed in the other mold, and a foaming solution such as polyurethane is cast between these to form a foamed layer 6 to form a slush adult skin. To form a molded body.

[0041]

Next, the present invention will be described in more detail with reference to specific examples. Examples 1 to 5, Comparative Examples 1 and 2 As an outer layer, as shown in Table 1, a polypropylene resin (P
P resin), ethylene-octene copolymer (POE), an internal mold release agent, and an organic peroxide that are dry-blended with a tumbler, are twin-screw extruders (PCM45, manufactured by Ikegai Iron and Steel Co., Ltd.)
The mixture was kneaded at a cylinder temperature of 210 ° C. and a screw rotation speed of 300 rpm while extruding process oil from a vent port, and extruded into pellets. Subsequently, dry blending of the above-mentioned kneaded pellets, H-SBR, phenolic antioxidant, phosphite-based oxidant, hindered amine-based light stabilizer, and benzotriazole-based light stabilizer was supplied to the same twin-screw extruder as raw materials. The mixture was supplied from a hopper, kneaded under the same conditions while injecting process oil from a vent port, and extruded into pellets. Then, the pellets immersed in liquid nitrogen are put into a turbo mill T250-4J (manufactured by Turbo Industries, Ltd.) and pulverized.
Only the 1,000 μm sieve pass was collected.

The inner layers were prepared according to the formulation shown in Table 1, respectively.
Resin, H-SBR, POE, two types of olefin polymers having hydroxyl groups, and olefin crystal / ethylene / butylene / olefin crystal copolymer (CEB) as a compatibilizer
C) A dry blend of a hydrogenated terpene resin as a plasticizer, an organotin catalyst, a phenolic antioxidant, and a phosphite-based oxidant as a catalyst for accelerating the reaction with isocyanate, and biaxial under the same conditions as the outer layer. Kneading was performed with an extruder. After kneading, the mixture was extruded into pellets, and the pellets immersed in liquid nitrogen were put into a Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.) and pulverized.

[0043]

[Table 1]

Next, slush molding was performed using the above powder. As a method of slush molding, a plate of 150 mm x 150 mm x 3 mm with a grain pattern is heated to 270 ° C in an oven, and about 800 g of the powder for the outer layer is put on the plate for 5 seconds to adhere. After that, the powder which did not adhere to the melt was removed, and heated in an oven adjusted to 300 ° C. for 60 seconds to form an outer layer having a thickness of 0.6 mm. Then, about 800 g of powder for the inner layer was placed on the outer layer.
After placing on the plate for 8 seconds, a layer having a thickness of 0.2 mm was formed except for the powder that did not adhere by melting.

Thereafter, the melting time and cooling conditions were changed as follows, and molding conditions 1 to 3 were set. First, in order to reproduce variations in molding temperature, the melting time of the inner layer was changed to 30, 60 seconds in an oven adjusted to 300 ° C. The melted skin was taken out of the oven and cooled, and the cooling method was water-cooled and room-temperature air-cooled in order to reproduce variations in the molding cycle pitch, and the time required for the molded plate to cool to room temperature was changed. After cooling, the skin having a thickness of about 0.8 mm was removed.

In order to improve the scratch resistance of the outer layer, a surface treatment agent REZALOY LU-775SP manufactured by Dainichi Seika Kogyo Co., Ltd. is applied to the surface of the outer layer by spraying, and a urethane-based transparent paint LAZLOID LU-2408 is applied thereon. Spray
And then dried and heated in an oven at 80 ° C. for 30 minutes. In the evaluation of adhesiveness using the skin, 200 mm ×
160 mm x 16 with an adhesive surface preliminarily flame treated on an aluminum upper and lower mold with a space of 200 mm x 7 mm
Set a polypropylene plate of 0 mm x 3.0 mm,
Set the composite epidermis on the lower mold, and mix 2
After injecting about 120 g of the liquid semi-rigid urethane foam raw material liquid, the upper and lower molds were fixed together with a hook and cured for 5 minutes, and then the upper and lower molds were opened to take out the skin and the urethane foam laminate. This was cut out to a width of 25 mm and a length of 150 mm to obtain a sample for evaluation.

The adhesiveness between the skin and the urethane foam layer was evaluated by evaluating the adhesiveness at normal temperature in the peeled state and the 180 ° peel strength. In the peeling state, the cohesive failure rate 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. Peel strength is 200 pulling speed
The measurement was performed at a rate of mm / min. If the pressure was 0.03 MPa or more, the result was evaluated as 、.

The adhesiveness after heat aging was evaluated by leaving the sample for evaluation for 24 hours in an oven at 120 ° C. for 24 hours, and then for 24 hours at room temperature. .

The adhesiveness at a high temperature was measured by applying a load of 150 g to the skin side of the evaluation sample in a 120 ° C. atmosphere.
It was left standing for minutes, and it was evaluated whether the skin and the urethane foam were held without peeling, and the holding was evaluated as ○, and the peeled was evaluated as ×. In addition, the cohesive failure of urethane foam, but the physical properties of the epidermis are low,
And

All the evaluations of the adhesiveness were also made after the lapse of days after the surface coating treatment (7 days).

For the tensile properties, the skin obtained by slush molding was punched out with a JIS No. 3 dumbbell, and the tensile speed was 200 m.
The tensile strength and tensile elongation were measured at m / min. The melt viscosity was measured at 230 ° C according to JIS K7210 at 21 ° C.
The melt flow rate (MFR) was measured at a load of 18N. Table 2 shows the test results.

[0052]

[Table 2]

As a result, in the examples, the releasability of the skin from the mold was good, and the adhesion between the inner layer of the skin and the urethane foam was more dependent on the molding conditions than in the comparative example in which the compatibilizer was not added. It can be seen that the adhesive strength was particularly high at a high temperature and was maintained even after several days. Comparative Example 2 in which a large amount of an ethylene / octene copolymer was added
Although the adhesion at room temperature is slightly improved, the tensile properties are reduced because no compatibilizer is added. However, in Example 2 in which the same amount of the ethylene-octene copolymer was added, the adhesiveness was improved, and the decrease in physical properties was alleviated. In addition, the adhesiveness at high temperature was also measured in Example 2.
However, in Comparative Example 2, the skin was softened and could not maintain high adhesiveness, and the skin was broken due to a decrease in physical properties. This is considered to be because the matrix layer of the composition became an ethylene / octene copolymer having a low melting point.

[0054]

As described above, in the invention relating to the thermoplastic elastomer composition for slush molding according to the claims of the present invention, at least the polypropylene resin, the hydrogenated styrene-butadiene rubber, the ethylene / octene copolymer, the active hydrogen A thermoplastic elastomer for slush molding, comprising an olefin polymer having a terpolymer, a catalyst for accelerating the reaction of isocyanate, a plasticizer, and an olefin crystal / ethylene butylene / olefin crystal block copolymer as a compatibilizer. In the composition, at least two layers consisting of an outer layer and an inner layer are continuously slush-molded, and the outer layer imparts excellent properties to the mold release, while the inner layer has excellent adhesion to the foam layer. I have.

[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;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument panel 2 Soft part 3 Hard part 4 Slash molding 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 symbol FI Theme coat ゛ (Reference) C08L 23/00 C08L 23/00 23/08 23/08 53/00 53/00 // B29K 9:06 B29K 9:06 23:00 23:00 (72) Inventor Osamu Okazawa 4-1-1, Hamazoedori, Nagata-ku, Kobe-shi, Hyogo F-term in Mitsuboshi Belting Co., Ltd. 3D054 AA03 AA14 BB09 BB10 BB16 BB30 FF01 FF02 FF17 FF18 4F070 AA08 AA12 AA13 AA15 AA40 AB01 AB02 AB08 AB09 AB11 AB16 AC40 AC46 AC47 AC52 AC53 AC56 AC67 AC92 AC94 AC95 AE02 AE08 AE16 AE17 AE17 EA04 FA03 FA17 FC06 GA05 GA06 GA08 GB09 GC02 GC08 4F205 AA03A A04 AA03A A04 AB04 GA12 GB01 GB22 GC04 4J002 AC08X AE05U AJ00U BA01U BB05Y BB07Z BB08Z BB12W BB14W BB15W BB20Z BE03Z BL01Z BP02W BP03U EG026 EG046 EN026 EN036 EZ046 FD02U FD140 FD20U GN00

Claims (6)

[Claims] 1. An olefin polymer having at least a polypropylene resin, a hydrogenated styrene butadiene rubber, an ethylene / octene copolymer, an active hydrogen, a catalyst for accelerating a reaction with isocyanate, a plasticizer, and an olefin crystal as a compatibilizer. A thermoplastic elastomer composition for slush molding, comprising an ethylene butylene / olefin crystal block copolymer. 2. The olefin crystal / ethylene butylene / olefin crystal block copolymer is 5 to 20 parts by weight based on 100 parts by weight of the mixture of the polypropylene resin and the ethylene / octene copolymer. 1
The thermoplastic elastomer composition for slush molding according to the above. 3. A composite skin in which at least an outer layer and an inner layer are laminated, wherein the inner layer reacts with at least a polypropylene resin, a hydrogenated styrene butadiene rubber, an ethylene / octene copolymer, an olefin polymer having active hydrogen, and an isocyanate. Promoting catalysts, plasticizers,
A composite skin obtained by subjecting a thermoplastic elastomer composition powder containing an olefin crystal / ethylene butylene / olefin crystal block copolymer as a compatibilizer to slush molding. 4. The olefin crystal / ethylene butylene / olefin crystal block copolymer is 5 to 20 parts by weight based on 100 parts by weight of the mixture of the polypropylene resin and the ethylene / octene copolymer. 3
The composite epidermis as described. 5. A thermoplastic elastomer composition powder containing at least a polypropylene resin, a hydrogenated styrene butadiene rubber, a plasticizer, an ethylene / α-olefin copolymer, an internal mold release agent, and an organic peroxide as the outer layer. 5. The molded article according to claim 3, wherein the molded article is formed.
The composite epidermis as described. 6. The composite skin according to claim 5, wherein said ethylene / α-olefin copolymer is an ethylene / octene copolymer.