JP2000044743A - Thermoplastic elastomer composition and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition which can give a product having a high-level light resistance and improved in fogging resistance without causing blooming by mixing an olefin resin with an ethylene/α-olefin copolymer rubber, and an N-alkyl hindered amine light stabilizer. SOLUTION: The olefin resin (A) is desirably a polypropylene, a copolymer of propylene with a 2C or α-olefin copolymer, or a polyethylene. The ethylene/α- olefin copolymer (B) is an ethylene/α-olefin copolymer rubber or an α-olefin/ nonconjugated diene copolymer rubber. The N-alkyl hindered amine light stabilizer (C) is desirably tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl-1,2,3,4-butane) tetracarboxylate. The weight ratio A/B is desirably 60/40 to 10/90, and the weight ratio C/(A+B) is desirably 0.01-1.0.

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, a laminate, a laminate for an automobile interior, an automobile interior part, and an instrument panel. More specifically, the present invention provides a thermoplastic elastomer composition which maintains light resistance at a satisfactory high level, does not involve bloom, and has improved fogging resistance, and lamination using the thermoplastic elastomer composition. TECHNICAL FIELD The present invention relates to a body, a laminate for an automobile interior, an automobile interior part, and an instrument panel.

[0002]

2. Description of the Related Art For automobile interior parts such as instrument panels (dashboards), laminates obtained by laminating a foam layer on a thermoplastic elastomer composition layer are being widely used. Here, the thermoplastic elastomer composition used for automobile interior parts is required to have excellent light resistance and also excellent fogging resistance. Here, fogging refers to a phenomenon in which various additives contained in the thermoplastic elastomer composition volatilize and adhere to the window glass, causing inconvenience such as deterioration in visibility. And, from the viewpoint of maintaining light resistance at a satisfactory high level and excellent fogging resistance, the thermoplastic elastomer laminate according to the prior art is hardly satisfactory. .

[0003]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to maintain a light resistance at a satisfactory high level, without causing bloom, and improving a heat resistance with improved fogging resistance. Another object of the present invention is to provide a thermoplastic elastomer composition, a laminate using the thermoplastic elastomer composition, a laminate for an automobile interior, an automobile interior part, and an instrument panel.

[0004]

That is, the first aspect of the present invention relates to a thermoplastic elastomer composition containing the following (A) to (C). (A): Olefin resin (B): Ethylene-α-olefin copolymer rubber (C): N-alkyl hindered amine light stabilizer

[0005] A second aspect of the present invention relates to a laminate obtained by laminating a foam layer on a layer comprising the thermoplastic elastomer composition of the first aspect.

[0008] A third aspect of the present invention relates to a laminate for an automobile interior comprising the laminate of the second aspect.

A fourth aspect of the present invention relates to an automobile interior part comprising the automobile interior laminate of the third aspect.

A fifth aspect of the present invention relates to an instrument panel comprising the laminate for an automobile interior according to the fourth aspect.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The component (A) is an olefin resin. As the olefin resin, polypropylene, a copolymer of propylene and an α-olefin having 2 or more carbon atoms, and polyethylene are preferable. Examples of the α-olefin having two or more carbon atoms include ethylene,
-Butene, 1-pentene, 3-methyl-1-butene, 1
-Hexene, 1-decene, 3-methyl-1-pentene,
4-methyl-1-pentene, 1-octene and the like. The melt flow rate of the olefin resin is usually 0.1 to 500 g / 10 minutes, preferably 0.5 to 500 g / 10 minutes.
The range is 300 g / 10 minutes.

The component (B) is an ethylene-α-olefin copolymer rubber. Examples of the ethylene-α-olefin copolymer rubber include an ethylene-α-olefin copolymer rubber and an ethylene-α-olefin-nonconjugated diene copolymer rubber.

The α-olefin in the ethylene-α-olefin-nonconjugated diene copolymer rubber includes, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, Examples thereof include 1-decene, and among them, propylene is preferred.
Examples of the non-conjugated diene include 1,4-hexadiene, 1,6-octadiene and 2-methyl-1,5-diene.
Hexadiene, 6-methyl-1,5-heptadiene, 7
Chain non-conjugated dienes such as -methyl-1,6-octadiene; cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene,
5-ethylidene-2-norbornene, 5-methylene-2
Cyclic non-conjugated dienes such as -norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropylenyl-2-norbornene; 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-
Trienes such as isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene and 1,4,9-decatriene are mentioned, among which 5-ethylidene-2-norbornene Or dicyclopentadiene is preferred.

The ratio (molar ratio) of ethylene / α-olefin in the ethylene-α-olefin copolymer rubber is usually 1 / (0.1 to 10).

When the ethylene-α-olefin-non-conjugated diene copolymer rubber is used, the content of the non-conjugated diene is as follows:
The iodine value is usually 2 to 25.

The ethylene-α-olefin copolymer rubber is preferably an ethylene-α-olefin copolymer rubber containing no non-conjugated diene from the viewpoint of light resistance and fogging resistance. In the case of producing an elastomer, the crosslinking density is insufficient, and the mechanical strength may be reduced. As a countermeasure against this inconvenience, a method using N, N'-m-phenylenebismaleimide or divinylbenzene as a cross-linking aid can be mentioned. Note that an ethylene-α-olefin copolymer rubber and an ethylene-α-olefin-non-conjugated diene copolymer rubber may be mixed and used as long as the object of the present invention is not impaired. Oil-extended rubber may be used as the ethylene-α-olefin-based copolymer rubber. As the oil-extended rubber, an oil-extended rubber containing 20 to 150 parts by weight of a mineral oil-based softener per 100 parts by weight of the rubber component is preferable. If the amount of the mineral oil-based softening agent is too small, the flexibility and moldability may be poor. On the other hand, if the amount of the mineral oil-based softening agent is too large, the surface of the skin material may become sticky.

As a preferred specific example of the ethylene-α-olefin copolymer rubber, a propylene or butene content of 5 to 80% by weight, preferably 10 to 60% by weight, more preferably 15 to 50% by weight is used. Propylene copolymer rubber can be used.

[0016] Ethylene-α-olefin copolymer rubber
Is the Mooney viscosity at 100 ° C. (ML _{1 + 4} 100 ℃) is 5
To 150, more preferably 10 to 10
0. If the Mooney viscosity is too low, the mechanical strength
If the Mooney viscosity is too high,
The appearance of the shape may be impaired.

(B) may be an ethylene-α-olefin copolymer rubber partially crosslinked by performing dynamic crosslinking in the presence of (A). By using such (B), advantages such as improvement in mechanical properties and excellent workability during secondary molding can be obtained.

The weight ratio of (A) / (B) in the thermoplastic elastomer composition is 60/40 to 10/90.
It is preferred that (A) is too small ((B) is too much)
In the case of (1), the fluidity is lowered and the sheet processability may be impaired. On the other hand, when (A) is too large ((B) is too small), a flexible thermoplastic elastomer may not be obtained. In the present invention, the amount and Mooney viscosity of (B) when an oil-extended rubber is used as (B) are based on values including a mineral oil-based softener.

The component (C) is an N-alkyl hindered amine light stabilizer. When a light stabilizer other than the N-alkyl hindered amine light stabilizer is used according to the conventional technique, fogging occurs. Preferred (C)
The component is an N-methyl hindered amine light stabilizer, and more preferably tetrakis (1,2,2,6,6-
Pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate.

The content of (C) is preferably from 0.01 to 1.0 part by weight, more preferably from 0.05 to 0.5 part by weight, per 100 parts by weight of the total of (A) and (B). Parts by weight. If the content of (C) is too small, the light resistance may be poor. On the other hand, if the content of (C) is too large, the fogging resistance may be deteriorated, and it is not economically advantageous.

The thermoplastic elastomer composition is a thermoplastic elastomer composition containing the above (A) to (C). In addition to the essential components (A) to (C), necessary Accordingly, various additives, various auxiliary materials, rubbers, thermoplastic elastomers, olefin-based resins, and the like can be contained as long as the object of the present invention is not impaired. Examples of the various additives include an antioxidant, an ultraviolet absorber, a lubricant, and an antistatic agent. Examples of various auxiliary materials include coloring pigments, fillers, and fillers such as calcium carbonate. Rubbers include natural rubber, butyl rubber, chloroprene rubber, acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, epichlorohydrin rubber, acrylic rubber, styrene-butadiene rubber, hydrogenated styrene-butadiene rubber, butadiene rubber, hydrogenated Examples include conjugated diene rubbers such as butadiene rubber. Examples of the thermoplastic elastomer include the same olefinic thermoplastic elastomers as those of the present invention, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-isoprene. Examples include styrene-based thermoplastic elastomers such as block copolymers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers. Examples of the olefin resin include polyethylene and polypropylene.

The thermoplastic elastomer composition can be obtained as a cross-linked composition or a non-cross-linked composition by a usual method, but a cross-linked composition is more preferable as a composition for automobile interiors. For example, crosslinked thermoplastic elastomer compositions are disclosed in JP-A-48-26838, JP-A-1-103639, and Japanese Patent Application No. 7-249442.
Can be obtained by the method disclosed in Japanese Patent Application Publication No. Further, the obtained crosslinked composition or non-crosslinked composition may further contain various additives, various auxiliary materials, rubbers, and thermoplastics, as described above, as long as the object of the present invention is not impaired. It is also possible to include an elastomer or an olefin resin.

The laminate of the present invention is a laminate obtained by laminating a foam layer on a layer made of the thermoplastic elastomer composition of the present invention. Hereinafter, a specific example of a method for manufacturing a laminate will be described.

First, a thermoplastic elastomer composition is extruded from an extruder by a T-die method, and a sheet-like thermoplastic elastomer in an extruded molten state is laminated with a polyethylene or polypropylene foam sheet to form a pair. A method of manufacturing by heat-sealing between rolls can be given.

Second, there is a method of producing a foam from a thermoplastic elastomer composition by a thermocompression bonding method or an adhesion method using an adhesive.

Third, there is a method of integrally producing a thermoplastic elastomer composition by a powder molding method (see Japanese Patent Application Laid-Open No. 5-473 and the like).

The above-described two-layer laminate with the foam may be used as a multilayer molded article in which a thermoplastic resin layer is laminated on the foam layer side, or as required, within a range that does not impair the object of the present invention. It is also possible to apply various primers and top coats on the surface of the thermoplastic elastomer layer (the opposite side where the foam is not laminated).

The method for producing a molded article obtained by molding the thermoplastic elastomer composition is not particularly limited, and examples thereof include an extrusion molding method, a press molding method, a calendar molding method, an injection molding method, and a powder slush molding method. And the like.

Examples of the foam constituting the foam layer constituting the laminate of the present invention together with the thermoplastic elastomer layer include a polypropylene foam, a polyethylene foam, and a polyurethane foam obtained by an electron beam crosslinking method. Polypropylene and polyethylene foams are preferred.

The laminate of the present invention can be optimally used as a laminate for automobile interiors. That is, it can be processed into an automobile interior part made of the laminate for an automobile interior. The automobile interior parts are optimally used as automobile interior parts such as instrument panel parts and door parts.

[0031]

Next, the present invention will be described specifically with reference to examples. The test method and sheet forming method used for measuring the physical properties in these examples and comparative examples are as follows.

(1) Mooney viscosity (ML _{1 + 4 at} 100 ° C.) Measured according to ASTM D927-57T. EP
DM was calculated by the following equation. log (ML1 / ML2)) = 0.0066 (△ PHR) ML1: Mooney viscosity of EPDM ML2: Mooney viscosity of oil-extended EPDM △ PHR: Oil extension amount per 100 parts by weight of EPDM

(2) Melt flow rate (MFR) Measured under the following conditions in accordance with JIS K-7210. Polypropylene: temperature 230 ° C, load 2.16 kg Polyethylene: temperature 190 ° C, load 2.16 kg

(3) Fogging test method An apparatus conforming to the ISO 6452 standard, for example, the apparatus shown in FIG. 1 was measured using a wind screen fogging tester WSF-1 manufactured by Suga Test Instruments Co., Ltd.
Here, the oil bath and cooling plate have temperature control,
The metal ring is chrome plated and the annular packing is made of silicone rubber. In the measurement of fogging, the temperature of the oil bath is adjusted to 100 ± 2 ° C., the temperature of the cooling plate is adjusted to 20 ± 2 ° C., and the sample is 80 mmφ. 2 samples
After heating in a beaker for 0 hour and taking out, 23 ± 2
After 1 ± 0.1 hour in an environment of 50 ° C. and 50% RH, the glossiness of the glass plate is measured. The gloss was measured using a digital gonio-gloss meter manufactured by Suga Test Instruments Co., Ltd. according to JIS K7105 60.
It is measured according to the degree of specular gloss. At the time of measurement, the thermoplastic elastomer composition layer and the foam layer are arranged such that the thermoplastic elastomer composition layer is located above (toward the glass plate) and the foam layer is located below.

(4) Glossiness retention The following describes a method of calculating the glossiness retention. The gloss of the glass plate after the test is R1, the glass plate is rotated by 90 degrees, the gloss is measured, and the values are R2, R3, R
4 is assumed. The average glossiness is calculated from R1, R2, R3, and R4, and this value is set to R. R = (R1 + R2 + R3 + R4) / 4 The gloss retention is the ratio of R to the gloss (R0) of the glass plate before the test. Gloss retention (%) = (R / R0) × 100

(5) Fogging resistance The degree of fogging of a glass plate subjected to a fogging test in accordance with ISO 6452 was visually observed, and the gloss retention with little fogging (described above) was 60% or more. And less than 60% with large haze was rated "x" (poor).

(6) Light Resistance Test The sheet was punched out with a JIS No. 3 dumbbell, and the sample was irradiated for 250 hours under the condition of a UV fade meter black panel temperature of 83 ° C. manufactured by Suga Test Instruments Co., Ltd., without water.

(7) Retention of elongation at break Elongation at tensile break was measured in accordance with JIS K6301. In addition, JIS No. 3 dumbbell, 200mm /
Minutes. The retention of elongation at tensile break was calculated based on the following equation. Elongation at break retention (%) = elongation at break at age / elongation at break before light or heat resistance test

(8) Bloom Property After the sheet-formed sample was stored in an environment of 23 ± 2 ° C. and 50% RH for 30 days, bloom on the sheet surface was visually observed.
The case where no blooming occurred was evaluated as “○” (good), and the case where blooming occurred was evaluated as “x” (bad).

Example 1 Preparation of thermoplastic elastomer pellets (1) TPO-1 EPM-1 (ethylene-propylene copolymer rubber, propylene content = 22% by weight, ML _{1 + 4} 100 ° C. = 35)
70 parts by weight of polypropylene-1 (MFR = 10 g / 1
0 minutes, homo type) 30 parts by weight and N,
0.4 parts by weight of N′-m-phenylenebismaleimide (“Sumifine BM” manufactured by Sumitomo Chemical Co., Ltd.), and Sumisorb 300 @ 2- (2-hydroxy-3) as a light stabilizer
-T-butyl-5-methylphenyl) -5-chlorobenzotriazole, molecular weight = 316: manufactured by Sumitomo Chemical Co., Ltd.
0.05 parts by weight, Irganox 101 as heat stabilizer
0 ｛pentaerythrityl-tetrakis [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate], molecular weight = 1177, manufactured by Ciba-Geigy {0.
1 part by weight with a Banbury mixer at 170-200 ° C x 7
After mixing and kneading, a pelletized master batch was prepared using an extruder. Next, 0.04 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane per 100 parts by weight of the master batch was uniformly blended for 3 minutes using a Henschel mixer. The obtained blend is twin-screw extruder (TEX-4 manufactured by Nippon Steel Works, Ltd.).
Using 4HC), a dynamic heat treatment was performed at 240 to 260 ° C. for about 30 seconds to obtain a partially crosslinked thermoplastic elastomer pellet (hereinafter, referred to as “TPO-1”).

(2) TPO-2 In the method of producing TPO-1, EPO-1 was used instead of EPM-1.
PDM-1 (ethylene-propylene-ethylidene norbornene (ENB) copolymer rubber, iodination = 12, propylene content = 28% by weight, ML _{1 + 4} 100 ° C. = 242)
Of a mineral oil-based softening agent ("Diana Process Oil PW-380" manufactured by Idemitsu Kosan Co., Ltd.) per 100 parts by weight of EPDM-1 in a 5% by weight hexane solution, and then the solvent is removed by steam stripping. 85 parts by weight of the oil-extended EPDM-1 (ML _{1 + 4} 100 ° C. = 53) and 15 parts by weight of polypropylene-2 (MFR = 1 g / 10 min, random type) obtained as above and N, N ′ as a crosslinking aid
0.4 parts by weight of m-phenylenebismaleimide, 0.2 parts by weight of Sumisorb 300 as a light stabilizer, 0.15 parts by weight of Irganox 1010 as a heat stabilizer, and Neutron S (erucamide, A thermoplastic elastomer pellet (hereinafter, referred to as "TPO-2") produced in the same manner as TPO-1 except that the amount was changed to 0.1 part by weight (Nippon Seika Co., Ltd.) was obtained.

The thermoplastic elastomer composition and the laminate
Preparation 56 parts by weight of the above TPO-1, 24 parts by weight of TPO-2, polyethylene (MFR = 2), Irganox 1076 {octadecyl-3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate, molecular weight = 530, 0.15 parts by weight, manufactured by Ciba-Geigy, Irgafos 168 [Tris (2,4-di-t-
Butylphenyl) phosphite, molecular weight = 647, manufactured by Ciba-Geigy Co.] 0.12 parts by weight. {20 parts by weight and LA52 as a hindered amine light stabilizer} tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, molecular weight = 847 Asahi Denka After blending 0.3 parts by weight of｝ with a Henschel mixer, using a twin screw extruder (TEX-44HC, manufactured by Nippon Steel Works),
Dynamic heat treatment was performed at 0 to 260 ° C. for about 30 seconds, and the mixture was pelletized to obtain a thermoplastic elastomer composition. Next, a USV type 25 mmΦ extruder manufactured by Union Plastics (full flight type screw, screw rotation speed 40 r)
pm, T-die) to form a sheet of the thermoplastic elastomer. The resulting sheet was subjected to a bloom evaluation and a light resistance test, and the light resistance was evaluated based on the retention of elongation at break after a lapse of time. Table 1 shows the evaluation results. The composition was subjected to lamination molding to obtain a laminate. At the time of lamination molding, a sheet of 0.5 mmt is molded using a 25 mmΦ extruder, and PPF (polypropylene foam, Toray PPSM)
15030) to form an extruded laminate. A fogging test was performed on a sample cut out from the sheet at 80 mmφ. Table 1 shows the evaluation results.

Comparative Example 1 In the preparation of the thermoplastic elastomer composition and laminate of Example 1, SANOL LS-77 was used instead of LA52.
0 [bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, molecular weight = 481, manufactured by Sankyo Co., Ltd.].
A thermoplastic elastomer composition and a laminate were obtained in the same manner as in Example 1 except that 3 parts by weight were added. A light resistance test was performed using this composition, and a fogging test was performed using the laminate. Table 1 shows the evaluation results.

Comparative Example 2 A thermoplastic elastomer composition was obtained in the same manner as in Example 1 except that LA52 was omitted in the preparation of the thermoplastic elastomer composition and the laminate of Example 1. A light fastness test was performed using this composition. Table 1 shows the evaluation results.

[0045]

[Table 1] * 1 LA-52: Tetrakis (1,2,2,6,6-
Pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate * 2 LS-770: bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate

[0046]

As described above, according to the present invention, a laminated body for an automobile interior, which maintains light resistance and the like at a satisfactory high level and has improved fogging resistance, and an automobile comprising the laminated body and the laminated body for an automobile interior Interior parts could be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fogging haze measuring device according to ISO6452.

Continued on the front page F-term (reference) 3D044 BA00 BB01 BC02 4F100 AH02 AH03 AH03H AK03B AK04A AK07 AK07A AK27B AK51A AK62B AK64 AK64B AL01B AL09B 076

Claims (15)

[Claims] 1. A thermoplastic elastomer composition containing the following (A) to (C). (A): Olefin resin (B): Ethylene-α-olefin copolymer rubber (C): N-alkyl hindered amine light stabilizer 2. The thermoplastic elastomer composition according to claim 1, wherein (A) is polypropylene and / or polyethylene. 3. The thermoplastic elastomer composition according to claim 1, wherein (B) is an ethylene-α-olefin copolymer rubber or an ethylene-α-olefin-nonconjugated diene copolymer rubber. 4. The thermoplastic elastomer composition according to claim 1, wherein the α-olefin of (B) is propylene. 5. The thermoplastic elastomer composition according to claim 1, wherein (B) is an oil-extended rubber containing 20 to 150 parts by weight of a mineral oil-based softener per 100 parts by weight of the rubber component. 6. The thermoplastic elastomer composition according to claim 1, wherein (B) is an ethylene-α-olefin copolymer rubber partially crosslinked by performing dynamic crosslinking in the presence of (A). object. 7. The weight ratio of (A) / (B) is 60/40.
The thermoplastic elastomer composition according to claim 1, wherein the ratio is from 10 to 90/90. 8. The thermoplastic elastomer composition according to claim 1, wherein (C) is an N-methyl hindered amine light stabilizer. 9. (C) is tetrakis (1,2,2,9)
6,6-pentamethyl-4-piperidyl) 1,2,3
The thermoplastic elastomer composition according to claim 1, which is 4-butanetetracarboxylate. 10. The thermoplastic elastomer composition according to claim 1, wherein the content of (C) is 0.01 to 1.0 part by weight per 100 parts by weight of the total amount of (A) and (B). 11. A laminate obtained by laminating a foam layer on a layer comprising the thermoplastic elastomer composition according to claim 1. 12. The laminate according to claim 10, wherein the foam layer comprises a foam of polypropylene, polyethylene or polyurethane. 13. A laminate for an automobile interior, comprising the laminate according to claim 10. 14. An automobile interior part comprising the laminate for an automobile interior according to claim 12. 15. An instrument panel comprising the laminate for an automobile interior according to claim 12.