JP2011057911A - Thermoplastic resin composition and surface sheet of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of vinyl chloride resin (PVC), which has been hitherto widely used as a surface sheet, for example, as a surface sheet of an automobile interior parts, but has problems in light resistance, fogging resistance, and lightweight properties; and also to solve problems of a polyolefin-based thermoplastic soft surface sheet, which has been considered to be a promising alternative for a PVC surface sheet, but has poor abrasion resistance and poor vacuum formability, such as embossing holding properties. <P>SOLUTION: A particular olefin-aromatic vinyl compound-based cross copolymer is compounded with a polyphenylene ether and microcrystalline wax, resulting in improvement in abrasion resistance and embossing holding properties, as well as production of a sheet which hardly causes blocking and bleeding and generates reduced die build-up upon the secondary formation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a thermoplastic resin composition containing an olefin-aromatic vinyl compound-based cross-copolymer, polyphenylene ether, and microcrystalline wax, and a skin sheet thereof.

Conventionally, vinyl chloride resin (PVC) has been widely used as a skin sheet, for example, a skin sheet for automobile interior materials. However, the skin sheet for automobile interior materials using vinyl chloride resin has problems in light resistance, fogging resistance, and lightness. Accordingly, polyolefin-based thermoplastic soft skin sheets having good properties have been regarded as promising alternatives to vinyl chloride resin skin sheets.

However, the polyolefin-based thermoplastic soft skin sheet has a problem that it is inferior in vacuum formability such as abrasion resistance and texture retention as compared with the vinyl chloride resin skin sheet.

As a thermoplastic resin that can improve the abrasion resistance of a polyolefin-based thermoplastic elastomer, there is a styrene-ethylene copolymer (Patent Document 1). However, the retention of a sheet using this polymer is inferior to that of PVC. There was a problem that the abrasion was slightly lower than PVC.

There is also a technique of blending a styrene-ethylene copolymer with polyphenylene ether (Patent Document 2), but although the heat resistance is improved, the texture retention and wear resistance have not reached the level of PVC. In addition, when the secondary processing is carried out into a sheet shape, the problem of damage to the appearance due to adherence of the eye-gear-like substance (hereinafter referred to as eye-gear) generated at the die port of the processing apparatus, and the sheet does not cause blocking. Thus, improvement of blocking resistance is required.

In order to improve blocking resistance, a method of adding microcrystalline wax to a polyolefin-based thermoplastic elastomer is also described (Patent Document 3), but even in the disclosed method, heat resistance, wear resistance, and retention However, it does not sufficiently satisfy the balance of the property, blocking resistance, bleed resistance, etc., and its improvement is demanded.

Therefore, it is equivalent to vinyl chloride resin skin sheet, or better than that, it has excellent heat formability such as heat resistance, wear resistance, texture retention, etc., and also has blocking resistance, bleed resistance, and reduction in eyes. The appearance of a sheet is desired.

JP 2000-119456 A JP 2000-198918 A JP-A-2005-139326

The present invention is intended to solve the problems associated with the above-described prior art, and is a thermoplastic resin excellent in heat resistance, wear resistance, texture retention, reduction in eyes, blocking resistance, and bleed resistance. It aims at providing the sheet | seat for skin which consists of a composition and this composition.

As a result of intensive studies to obtain a thermoplastic resin composition excellent in heat resistance, wear resistance, grain retention, reduction in eyes, blocking resistance, and bleed resistance, the present inventors have obtained specific olefin-fragrance. In addition to improving heat resistance, abrasion resistance, and grain retention, the sheet can be formed into a sheet by secondary molding processing by blending an aromatic vinyl compound-based cross-copolymer with polyphenylene ether and microcrystalline wax. The present inventors have found that a thermoplastic resin composition that is less likely to cause eye discoloration, blocking, and bleeding is obtained, and the present invention has been completed.

In the present invention, a specific olefin-aromatic vinyl compound-based cross-copolymer, polyphenylene ether, and microcrystalline wax are blended to improve sufficient heat resistance, wear resistance, and wrinkle retention property. It becomes possible to produce a thermoplastic resin composition in which the sheet is less likely to cause discoloration, blocking, or bleeding even after the next molding process.

Conceptual diagram showing the cross-copolymer structure Schematic diagram showing graft copolymer structure

The present invention is a thermoplastic resin composition containing an olefin-aromatic vinyl compound-based cross-copolymer, polyphenylene ether, and microcrystalline wax. Below, each component is demonstrated in detail.

The olefin-aromatic vinyl compound-based cross-copolymer (hereinafter abbreviated as cross-copolymer) is an olefin-aromatic vinyl compound-aromatic polyene copolymer and aromatic vinyl, which are main chains as shown in FIG. It is a copolymer mainly having a structure in which a polymer containing a compound is cross-linked at one point or a plurality of points via an aromatic polyene unit. Such a cross structure can be rephrased as a star structure. Moreover, in the classification | category in American Chemical Society POLY subcommittee, it is called Segregated star polymer (Polymer preprints, 1998, March). Hereinafter, a polymer containing an aromatic vinyl compound that is cross-linked to the main chain olefin-aromatic vinyl compound-aromatic polyene copolymer is referred to as a cross chain.
On the other hand, as shown in FIG. 2, the graft copolymer known to those skilled in the art is a copolymer mainly having a polymer chain branched from one point or a plurality of points of the main chain. The structure in which the polymer main chain and other polymer chains are cross-bonded, when used as a composition or compatibilizer, generally provides superior strength at the polymer microstructure interface compared to the graft structure, It is believed to give high mechanical properties.

The cross-copolymer used in the present invention is not only a concept indicating the cross-copolymer itself, but also a cross-copolymer and an uncrosslinked olefin-aromatic vinyl compound copolymer and / or aromatic. The concept of a composition containing a vinyl compound polymer in an arbitrary ratio is included.

The content of the aromatic vinyl compound unit in the main chain of the cross copolymer used in the present invention is 10 mol% or more and 40 mol% or less. When the aromatic vinyl compound unit content is less than 10 mol% or more than 40 mol%, when blended with polyphenylene ether, there is a problem that the softness is lost due to an increase in hardness and there is a disadvantage that the texture retention is lowered.

The content of the aromatic polyene unit in the main chain of the cross copolymer used in the present invention is 0.01 mol% or more and 0.5 mol% or less. When the aromatic polyene unit content is less than 0.01 mol%, the properties as a cross-copolymer are not sufficient, and when it exceeds 0.5 mol%, the moldability is deteriorated. Furthermore, when the aromatic polyene unit content is 0.02 mol% or more and 0.2 mol% or less, the main chain olefin-aromatic vinyl compound-aromatic polyene copolymer is used for the physical properties of the cross-copolymer. The combined functionality is fully utilized. When the aromatic polyene unit content is 0.2 mol% or more, the average chain length between aromatic polyene units is shortened, and the functionality of the main chain olefin-aromatic vinyl compound-aromatic polyene copolymer is reduced. May not be fully utilized.

The mass ratio of the main chain of the cross copolymer used in the present invention is 60% by mass or more and 80% by mass or less. When the mass ratio of the main chain is less than 60 mass% or more than 80 mass%, the wear resistance when blended with polyphenylene ether is lowered. Further, when there is no cross chain and the main chain is 100% by mass, when blended with polyphenylene ether, heat resistance is improved, but there is a problem that grain retention and wear resistance are lowered.

As the olefin used in the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms, that is, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, vinylcyclohexane and cyclic olefin, That is, cyclopentene and norbornene are exemplified. Preferably, ethylene or a mixture of ethylene and an α-olefin, that is, propylene, 1-butene, 1-hexene, or 1-octene is used, and more preferably, ethylene is used.

The aromatic vinyl compound used in the present invention includes styrene and various substituted styrenes such as p-methylstyrene, m-methylstyrene, o-methylstyrene, ot-butylstyrene, mt-butylstyrene, p- Examples thereof include t-butylstyrene. Industrially, styrene, p-methylstyrene, and particularly preferably styrene is used.

The aromatic polyene used in the present invention is an aromatic polyene having 10 to 30 carbon atoms and having a plurality of double bonds (vinyl group) and one or more aromatic groups. Preferably, one or a mixture of two or more of paradivinylbenzene and metadivinylbenzene is preferably used.

The cross-copolymer used in the present invention can be produced by a production method based on International Publication No. WO00 / 37517.

A commercially available polyphenylene ether can be used for the present invention. Polyphenylene ethers are prepared by techniques well known in the art such as the oxidation of phenol with an oxygen-containing gas in the presence of a catalyst system consisting of, for example, a cuprous salt and a tertiary amine. Examples of the polyphenylene ether include homopolyphenylene ether resins and polyphenylene ether copolymers having a repeating unit represented by the following general formula [Chemical Formula 1].

式中、Ｑ１、Ｑ２、Ｑ３およびＱ４は独立して水素、炭化水素基、ハロゲン原子とフェノール核との間に少なくとも２個の炭素原子を有するハロ炭化水素基、ハイドロカルボノキシ基からなる群から選択され、さらにＱ２、Ｑ３およびＱ４はハロゲンとすることもできる。ｎはモノマー残基の合計数を示し、少なくとも５０以上の整数である。

Wherein Q1, Q2, Q3 and Q4 are independently hydrogen, a hydrocarbon group, a halohydrocarbon group having at least two carbon atoms between a halogen atom and a phenol nucleus, or a hydrocarbonoxy group. And Q2, Q3 and Q4 can also be halogen. n represents the total number of monomer residues and is an integer of at least 50 or more.

As the polyphenylene ether used in the present invention, poly (2,6-dimethyl-1--4-phenylene) ether is particularly suitable.

A commercially available microcrystalline wax can be used in the present invention. Examples thereof include Hi-MiC manufactured by Nippon Seiwa Co., Ltd. and BE Square manufactured by Barico Co., Ltd.

The amount of the cross copolymer used in the present invention is 70 parts by mass or more and 90 parts by mass or less, preferably 75 parts by mass or more and 85 parts by mass or less. When the amount is less than 70 parts by mass, the wear resistance is lowered, and when it exceeds 90 parts by mass, the heat resistance is insufficient.

The compounding quantity of the polyphenylene ether used for this invention is 10 to 30 mass parts, Preferably it is 15 to 25 mass parts. When the blending amount is less than 10 parts by mass, the heat resistance is insufficient, and when it exceeds 30 parts by mass, the wear resistance is reduced.

The compounding amount of the microcrystalline wax used in the present invention is 0.1 parts by mass or more and 3 parts by mass or less, preferably 0.1 parts by mass or more and 2.7 parts by mass with respect to 100 parts by mass in total of the cross copolymer and the polyphenylene ether. It is not more than mass parts, more preferably not less than 0.3 parts by mass and not more than 2.5 parts by mass. If the blending amount is less than 0.1 parts by mass, the effect of preventing the generation of the eyes and blocking is insufficient, and if it exceeds 3 parts by mass, the loss of practicality due to the stickiness of the sheet surface, the generation of the eyes, and bleeding are generated. .

The resin composition containing the cross-copolymer of the present invention can be blended with any known plasticizer conventionally used for vinyl chloride and other resins. The plasticizer preferably used is an oxygen-containing or nitrogen-containing plasticizer, and is an ester plasticizer, an epoxy plasticizer, an ether plasticizer, an amide plasticizer, or a paraffin oil.

These plasticizers have a relatively good compatibility with the cross-copolymer of the present invention, are difficult to bleed, and have a large plasticizing effect that can be evaluated by the degree to which the glass transition temperature is lowered. I can do it. When these plasticizers are used, the isotactic alternating structure of the ethylene and aromatic vinyl compound units in the cross-copolymer of the present invention, particularly the ethylene-aromatic vinyl compound-divinylbenzene copolymer, as a specific effect. In addition to the usual plasticizing effect, the effect of improving heat resistance and oil resistance can be exhibited.

Examples of ester plasticizers that can be suitably used in the present invention include various phthalic acid esters, trimellitic acid esters, adipic acid esters, sebacic acid esters, azelate esters, citric acid esters, acetyl citrate esters, and glutamic acid. Mono-fatty acid esters such as esters, succinic acid esters, and acetic acid esters, phosphoric acid esters, and polyesters thereof.

Examples of the epoxy plasticizer that can be suitably used in the present invention include epoxidized soybean oil and epoxidized linseed oil.

Examples of ether plasticizers that can be suitably used in the present invention include polyethylene glycol, polypropylene glycol, copolymers thereof, and mixtures thereof.

Examples of amide plasticizers that can be suitably used in the present invention include various sulfonic acid amides.

These plasticizers may be used alone or in combination.

The compounding amount of the plasticizer is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the cross copolymer of the present invention or the resin composition thereof. If the amount is less than 1 part by mass, the above effect is insufficient, and if it exceeds 30 parts by mass, it may cause bleeding, excessive softening, and excessive stickiness.

The method for blending the resin composition of the present invention and the plasticizer is not particularly limited, and any known appropriate blending method can be used. For example, melt mixing can be performed with a single-screw or twin-screw extruder, a Banbury mixer, a plast mill, a kneader, a heating roll, or the like. Prior to melt mixing, the raw materials may be mixed uniformly with a Henschel mixer, ribbon blender, super mixer, tumbler, or the like. The melt mixing temperature is not particularly limited, but is generally 100 ° C. or higher and 300 ° C. or lower, preferably 150 ° C. or higher and 250 ° C. or lower.

The thermoplastic resin composition of the present invention is molded by various molding methods. Examples of general molding methods include injection molding, press molding, sheet molding, profile extrusion molding, inflation molding, and vacuum molding. Examples of the transfer of wrinkles include injection molding, press molding, roll transfer, and vacuum molding. For example, the skin for automobile interior parts (door trim, instrument panel, console box, sun visor, glove box) and the skin of household appliances (TV, game console, DVD recorder, personal computer, mobile phone) used.

EXAMPLES Hereinafter, although an Example demonstrates this invention, these Examples do not limit this invention.

The analysis methods described in Examples and Comparative Examples were performed by the following means.

The analytical value of the polymer obtained in the coordination polymerization step (main chain) is determined by depositing a small amount (several tens of ml) of the polymer sampled at the end of the coordination polymerization step in methanol and recovering the polymer. -Yield, composition, molecular weight, etc. were determined.

The divinylbenzene content of the polymer obtained in the coordination polymerization step (main chain) was determined from the difference between the amount of unreacted divinylbenzene in the polymerization solution obtained by gas chromatography analysis and the amount of divinylbenzene used in the polymerization. .

As for the molecular weight of the cross copolymer component, the weight average molecular weight and the number average molecular weight in terms of standard polystyrene were determined using GPC (gel permeation chromatography).
When the cross-copolymer is soluble in tetrahydrofuran at room temperature, the Hitachi L-5030 column is composed of two TSK-GEL Multipore HXL-M (manufactured by Tosoh Corporation) in series and the flow rate of liquid feed using tetrahydrofuran as a solvent. It measured at 1.0 ml / min and 40 degreeC. When the cross copolymer is insoluble in tetrahydrofuran at room temperature, HLC-8121GPC / HT manufactured by Tosoh Corporation is used. It measured at 0 ml / min and 145 degreeC.

Determination of the styrene content in the cross copolymer component was performed by ¹ H-NMR, and α-500 manufactured by JEOL Ltd. was used as the instrument. It dissolved in deuterated 1,1,2,2-tetrachloroethane, and the measurement was performed at 80 ° C. or higher and 100 ° C. or lower. The area intensity of the peak derived from a phenyl group proton (6.5 ppm to 7.5 ppm) and the proton peak derived from an alkyl group (0.8 ppm to 3 ppm) was compared with TMS as a reference.

The melting point and penetration of the microcrystalline wax were measured according to JIS K-2235.

<MFR>
MFR was measured according to the flow test method of JIS K-7210 thermoplastics. The measurement was performed at a temperature of 220 ° C. and a test load of 10 kg.

<Hardness>
The hardness was determined as a type A durometer hardness according to the JIS K-6253 plastic durometer hardness test method. This hardness is an instantaneous value.

<Heat resistance>
A sheet with a grain (250 × 250 × 0.4 mm) was produced by press molding. This sheet was heat-treated in a gear oven at 100 ° C. for 3 hours, the length of the long side before and after the treatment was measured, and three-stage evaluation was performed.
Three-stage evaluation deformation rate is less than 3% A
Deformation rate is 3% or more and 5% or less B
Deformation rate is over 5% C
Deformation rate = 100 x (length after test-length before test) / length before test Note): () is the absolute value

<Abrasion resistance>
The above wrinkled sheet was cut into a size of 250 × 20 × 0.4 mm, and the wear resistance was evaluated with a Gakushin abrasion tester (rubbing tester manufactured by Tester Sangyo). The friction speed was 30 times / min, the test load was 500 g, and No. 6 canvas was used as the friction element. Three-stage evaluation was performed according to the number of times the sheet with wrinkles was torn.
Three-stage evaluation over 10,000 times A
5000 times or more and 10,000 times or less B
Less than 5000 times C

<Wrinkle retention>
A sheet with a grain (250 × 250 × 0.4 mm) was produced by press molding. The glossiness of this sheet was measured according to the optical characteristic test method of JIS K-7105 GS (60 °) plastic, and the remaining condition of the wrinkles was evaluated in three stages.
Less than 3 grade 3 (Wrinkle has almost disappeared) A
3 or more and 10 or less (the wrinkles have disappeared slightly) B
Over 10 (Wrinkles are almost gone) C

<Blocking resistance>
A sheet with a grain (250 × 250 × 0.4 mm) was produced by press molding. Ten sets of two sheets of this sheet were prepared and left for 1 month at a load of 500 g, a temperature of 40 ° C. and a humidity of 80%, and the number of blocking in the 10 sets was evaluated in three stages.
3-stage evaluation 0 set (no blocking) A
1 to 4 pairs (slightly blocking) B
5 to 10 pairs (almost blocking) C

<Bleed resistance>
A sheet with a grain (250 × 250 × 0.4 mm) was produced by press molding and left for 1 month at a temperature of 40 ° C. and a humidity of 80%. The glossiness before and after standing was measured according to the optical property test method of JIS K-7105 GS (60 °) plastic, and the bleeding resistance was evaluated in three stages.
Three-stage evaluation change rate is less than 3 A
Change rate is 3 or more and 5 or less B
Change rate is over 5 C
Change rate = (before leaving-after leaving) Note): () is the absolute value

<Eye dust generation amount>
Using a φ30mm T-die extrusion molding machine, melt-kneading at a screw speed of 40rpm and 230 ° C, forming a sheet of T-die width 120mm x 1mmt for 5 minutes, weighing the amount of spear generated at the die mouth, and evaluating in three stages did.
Three-stage evaluation less than 0.01g A
0.01g to 0.5g B
Over 0.5g C

<Experimental examples A to H>
Cross copolymers A to G and SE copolymer H were produced by a production method according to International Publication No. WO00 / 37517. For the SE copolymer H, only coordination polymerization was performed, and a sample was obtained without performing anionic polymerization. These analysis results are shown in Tables 1 and 2.

<Polyphenylene ether>
PX-100L polyphenylene ether (inherent viscosity 0.41, number average molecular weight 16000, weight average molecular weight 39000) manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.

<Microcrystalline wax>
Hi-MiC-2095, 1080, 1070 manufactured by Nippon Seiwa Co., Ltd. and BE Square 195 manufactured by Barico Co., Ltd. were used. These melting points and penetrations are shown in Table 3.

<Soft vinyl chloride resin>
As a comparative material according to the prior art, a soft vinyl chloride resin in which 50 parts by mass of plasticizer DINP and 80 parts by mass of calcium carbonate were blended with 100 parts by mass of polyvinyl chloride having an average molecular weight of 1300 was used.

<Antioxidant>
Irganox 1010 manufactured by Ciba Specialty Chemicals Co., Ltd. was used.

Examples 1-4 and Comparative Examples 1-20 are shown in Tables 4-7. The cross-copolymers A to G and SE copolymer H of the experimental examples were mixed with polyphenylene ether, microcrystalline wax, and antioxidant in the mass ratios shown in Tables 4 to 7, and the mixture was used at 230 ° C. using a φ30 mm twin screw extruder. The composition was melt-kneaded. In addition, a soft vinyl chloride resin (Comparative Example 8) was prepared as a comparative material related to the prior art. The pellets of the examples and comparative examples were press-molded at 200 ° C. to prepare various test pieces.

In Examples 1 to 4, heat resistance, wear resistance, grain retention, blocking resistance, bleed resistance, and amount of generation of eyes are all evaluated as A in sheet evaluation, and are superior to Comparative Examples 1 to 20. In Comparative Examples 1 to 6, the amount of polyphenylene ether deviates from 10 parts by mass or more and 30 parts by mass or less in the claims, and if it is less than 10 parts by mass, the heat resistance, the texture retention, and the amount of generated eyes are inferior. If it exceeds the mass part, the abrasion resistance and the amount of generation of eyes are inferior. Since Comparative Example 7 is an SE copolymer having no cross chain, the abrasion resistance, the texture retention, and the generation amount of eyes are inferior. The soft vinyl chloride resin of Comparative Example 8 is inferior in the grain retention and the amount of generation of eyes. In Comparative Examples 9 to 16, the amount of added microcrystalline wax is outside the range of 0.1 to 3 parts by mass of the claims, and when it is less than 0.1 parts by mass, the blocking resistance and the amount of generation of eyes are reduced. If it is inferior and exceeds 3 parts by mass, the bleed resistance and the amount of generated eyes will be inferior. In Comparative Examples 17 to 18, since the content of the aromatic vinyl compound unit in the main chain of the cross copolymer is outside the range of 10 mol% or more and 40 mol% or less of the claims, the hardness is increased to 90 or more and the softness is increased. Inferior to the problem of loss of texture and retention. Comparative Examples 19 to 20 are inferior in wear resistance because the mass ratio of the main chain of the cross copolymer is outside the range of 60 to 80 parts by mass.

From the above Examples and Comparative Examples, it can be seen that when a cross-copolymer having a composition limited to the scope of claims of the present patent, polyphenylene ether, and microcrystalline wax are blended, useful performance as a sheet for skin is expressed.

Claims (4)

70 to 90 parts by mass of the olefin-aromatic vinyl compound-based cross-copolymer, 10 to 30 parts by mass of the polyphenylene ether, and 100 parts by mass of the microcrystalline wax of 0.1 parts by mass. A thermoplastic resin composition containing at least 3 parts and at most 3 parts by mass. Olefin-aromatic whose main chain is composed of aromatic vinyl compound unit content of 10 mol% or more and 40 mol% or less, aromatic polyene unit content of 0.01 mol% or more and 0.5 mol% or less, and the balance is olefin unit The thermoplastic resin composition according to claim 1, comprising a vinyl compound-based cross copolymer. The thermoplastic resin composition of Claim 1 or 2 containing the olefin-aromatic vinyl compound type | system | group cross-copolymer whose mass ratio of a principal chain is 60 to 80 mass%. The skin sheet obtained by shape | molding the thermoplastic resin composition as described in any one of Claims 1-3.

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