JPH10147691A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having the flexibility imparted thereto without losing excellent characteristics possessed by an ionomer resin such as sufficient impact resilience, toughness and abrasion and oil resistances. SOLUTION: This resin composition comprises (a) 100 pts.wt. α-olefin- unsaturated carboxylic acid copolymer-based ionomer resin and (b) 5-200 pts.wt. thermoplastic elastomer composition, containing a block copolymer having >=1 polymer blocks A composed of a vinyl aromatic compound and >=1 polymer blocks (b) composed of an olefinic polymer and having <=-20 deg.C glass transition temperature and <=8cal/g heat of crystal fusion and having the content of the vinyl aromatic compound within the range of 5-50wt.% and 5-30 melt flow index measured at 200 deg.C under 2,160g load according to ASTM D-1238 and an acrylic resin, at (30/70) to (90/10) weight ratio of the former (a)/latter (b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition, more particularly, an α-olefin-unsaturated carboxylic acid copolymer ionomer resin, and a vinyl aromatic compound-olefin compound block copolymer and an acrylic resin. The present invention relates to a resin composition containing a thermoplastic elastomer composition.

[0002]

2. Description of the Related Art Conventionally, α-olefin-unsaturated carboxylic acid copolymer-based ionomer resins have been utilized in automobile parts, golf balls, ski shoes, etc. by utilizing their excellent toughness, abrasion resistance, oil resistance and the like. Among them, it is particularly used in the production of golf balls, taking advantage of its excellent rebound resilience. However, α-olefin-
In the unsaturated carboxylic acid copolymer-based ionomer resin, there is a positive correlation between rebound resilience and hardness, and when high rebound resilience is demanded, the hardness increases accordingly. Therefore, although a golf ball using an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin has a sufficient rebound resilience, there is a problem that the shot feeling is poor. Therefore, without deteriorating excellent properties such as rebound resilience, α
It is desired to impart flexibility to an olefin-unsaturated carboxylic acid copolymer ionomer resin.

As an attempt to impart flexibility to an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin,
JP-A-1-308577 discloses a soft ionomer resin, that is, a salt of a terpolymer comprising an olefinic compound, an unsaturated monocarboxylic acid, and an unsaturated monomer such as an acrylic ester is converted to an α-olefin-unsaturated carboxylic acid. It has been proposed to be blended with a copolymeric ionomer resin, and JP-A-5-345051 discloses that
It has been proposed to blend a specific saponified ethylene-ethyl acrylate copolymer into an α-olefin-unsaturated carboxylic acid copolymer ionomer resin. further,
U.S. Pat. No. 4,986,545 proposes to blend an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin with a thermoplastic elastomer modified with maleic anhydride or the like.

[0004]

However, molded articles obtained from the α-olefin-unsaturated carboxylic acid copolymer ionomer resin compositions described above and above are not yet satisfactory in terms of flexibility.
On the other hand, the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin composition described above gives a molded article having excellent flexibility.
It is said that satisfactory results can be obtained only when a thermoplastic elastomer modified with maleic anhydride or the like is used because of the compatibility with an olefin-unsaturated carboxylic acid copolymer ionomer resin. When an unmodified thermoplastic elastomer is blended with a carboxylic acid copolymer-based ionomer resin, the compatibility between the two is not sufficient, and the obtained molded article is described as having insufficient durability, such as impact resistance. . As described above, the α-olefin-unsaturated carboxylic acid copolymer resin composition which gives a molded article having excellent flexibility is relatively limited.

Thus, the present invention provides an α-olefin-unsaturated carboxylic acid having flexibility without impairing the excellent properties of an ionomer resin such as sufficient rebound resilience, toughness, abrasion resistance and oil resistance. It is an object of the present invention to newly provide a copolymer ionomer resin composition.

[0006]

Means for Solving the Problems The present inventors have developed a thermoplastic elastomer composition comprising a specific vinyl aromatic compound-olefinic compound block copolymer and an acrylic resin in an α-olefin-unsaturated carboxylic acid copolymer. The present inventors have found that a resin composition having excellent compatibility with a polymer-based ionomer resin and capable of solving the above-mentioned problems can be obtained by blending both, and as a result of further studies, the present invention has been completed.

That is, the present invention relates to (a) an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin 10
0 parts by weight, and (b) one or more polymer blocks A comprising a vinyl aromatic compound, and an olefinic polymer, having a glass transition temperature of -20 ° C or less and a heat of crystal fusion of 8 cal / g or less. It has at least one polymer block B, has a vinyl aromatic compound content in the range of 5 to 50% by weight, and has a content of 2 in accordance with ASTM D-1238.
The block copolymer and the acrylic resin having a melt flow index of 5 to 30 when measured at 00 ° C. and a load of 2160 g were mixed with the former / the latter = 30/70 to 90 /
Thermoplastic elastomer composition 5 contained in a weight ratio of 10
It is a resin composition containing about 200 parts by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) used in the present invention includes α-olefins such as ethylene and propylene and acrylic acid, methacrylic acid, itaconic acid and maleic acid. Copolymer of unsaturated carboxylic acid such as acid or α
-At least a part of the carboxyl group of the copolymer comprising the olefin, the unsaturated carboxylic acid and the ester thereof,
Sodium, potassium, lithium, copper, magnesium,
It means a resin that forms a salt with a metal cation such as zinc or aluminum.

In the present invention, any known α-olefin-unsaturated carboxylic acid copolymer ionomer resin can be used without any particular limitation. For example, “SURLYN” (manufactured by DuPont) can be used. (Trade name), manufactured by Mitsui Dupont Polychemical Co., Ltd.
Commercially available products such as “I-MILAN” ”(trade name) and“ IOTEK ”(trade name) manufactured by Exxon are preferably used. The α-olefin-unsaturated carboxylic acid copolymer ionomer resin (a) may be used alone or in combination of two or more.

The thermoplastic elastomer composition (b) used in the present invention comprises at least one polymer block A comprising a vinyl aromatic compound and an olefinic polymer, and has a glass transition temperature of -20.degree. Or less and a polymer block B having a heat of crystal fusion of 8 cal / g or less
And the content of the vinyl aromatic compound is 5 to 5
A block copolymer and an acrylic resin having a melt flow index of 5 to 30 when measured at 200 ° C. under a load of 2160 g according to ASTM D-1238 in the range of 0% by weight, and the former / the latter = 30/70. ~
A thermoplastic elastomer composition containing 90/10 by weight.

Examples of the vinyl aromatic compound constituting the polymer block A in the above block copolymer include styrene, α-methylstyrene, o-, m- or p-methylstyrene, and 2,4-dimethylstyrene. , Vinylnaphthalene, vinylanthracene and the like.
Of these, styrene and α-methylstyrene are preferably used. These vinyl aromatic compounds may be used alone or in combination of two or more.

The content of the vinyl aromatic compound in the block copolymer must be in the range of 5 to 50% by weight. When the content of the vinyl aromatic compound in the block copolymer is more than 50% by weight, the thermoplastic elastomer composition (b) does not have sufficient rubber elasticity, and the flexibility of a molded product obtained from the resin composition is impaired. I will. On the other hand, when the content of the vinyl aromatic compound in the block copolymer is less than 5% by weight, the strength of a molded article obtained from the resin composition decreases. The content of the vinyl aromatic compound in the block copolymer is preferably in the range of 10 to 35% by weight.

On the other hand, the polymer block B composed of an olefin polymer in the above block copolymer is a soft segment of the block copolymer, and has a glass transition temperature of -20 ° C. or less and a heat of crystal fusion. 8 cal /
g. When the glass transition temperature of the polymer block B is higher than −20 ° C., the molded product obtained from the resin composition is not provided with sufficient flexibility, and the heat of crystal fusion of the polymer block B is higher than 8 cal / g. When it is larger, the flexibility of the molded body is inferior. The structure of the polymer block B is not particularly limited as long as the glass transition temperature and the heat of crystal fusion are within the above ranges, but, for example, by appropriately adjusting the ratio of the alkyl branch, and the like, The polymer block B can have a glass transition temperature and a heat of crystal fusion within the above ranges.

Examples of the polymer block B composed of an olefin polymer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-butadiene.
In addition to pentadiene, 1,3-hexadiene or a hydrogenated polymer of a mixture thereof, isobutylene or α
-Olefin polymers and the like. Among these, those which are preferable as the polymer block B are hydrogenated products of polymers of 1,3-butadiene, isoprene or a mixture thereof.

When the polymer block B is a hydrogenated product of a polymer of a conjugated diene such as 1,3-butadiene or isoprene, 70% of the carbon-carbon double bond based on the conjugated diene is required.
% Or more is preferably hydrogenated, since a resin composition that gives a molded article having excellent heat aging resistance can be obtained, and the content of 1,2-bonds and 3,4-bonds is 50 mol%. The following is preferred because a resin composition giving a molded article having excellent flexibility can be obtained.

The melt viscosity of the block copolymer is ASTM.
According to D-1238, the melt flow index when measured at 200 ° C. and a load of 2160 g is 5 to 3
Must be 0. When the melt flow index of the block copolymer is less than 5, the compatibility with the acrylic resin is poor, and the resin composition obtained by blending with the acrylic resin and the ionomer resin has insufficient moldability. When the melt flow index of the block copolymer exceeds 30, the resin composition obtained by blending with the acrylic resin and the ionomer resin tends to exhibit adhesiveness.

Although the number average molecular weight of the block copolymer is not particularly limited, it is usually from 5,000 to 100,000.
It is within the range of 0. In addition, the number average molecular weight of the block copolymer in the present invention is a number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The molecular structure of the block copolymer is linear,
It may be either branched or any combination thereof. Further, the block copolymer may have a substituent such as a hydroxyl group, a carboxyl group, an epoxy group, an amino group, a halogen atom or the like at the molecular terminal or in the molecular chain as long as the properties are not lost.

As the method for producing the block copolymer, known methods can be used without any particular limitation. Methods for hydrogenating the polymer obtained by anionic polymerization, cationic polymerization, Ziegler polymerization, single-site polymerization, and the like. Polymerization method,
Any method such as a radical polymerization method may be used.

On the other hand, as the acrylic resin, a homopolymer of methyl methacrylate or a copolymer obtained by copolymerizing methyl methacrylate as a main component with a small amount of another monomer is preferably used. Here, as other monomers, for example, acrylic acid; metal acrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate,
Acrylic esters such as s-butyl acrylate, t-butyl acrylate and 2-ethylhexyl acrylate;
Methacrylic acid; metal methacrylate; methacrylates such as ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, and cyclohexyl methacrylate Acetates such as vinyl acetate; aromatic vinyl compounds such as styrene and α-methylstyrene; maleimides such as maleic anhydride, monoalkyl maleate, dialkyl maleate, and N-phenylmaleimide; Can be Also, although not limited, in the present invention, an acrylic resin in chloroform, 25%
Those having an intrinsic viscosity in the range of 0.2 to 1 dl / g when measured at ° C are usually used.

The blend ratio between the block copolymer and the acrylic resin must be the former / the latter = 30/70 to 90/10 (weight ratio). When the proportion of the acrylic resin is less than the above range, the molded article obtained from the resin composition of the present invention has a large decrease in hardness, while, when the proportion of the acrylic resin is greater than the above range, excellent flexibility is obtained. A molded article cannot be obtained. The blend ratio of the block copolymer and the acrylic resin is the former / the latter = 30 / 70-70 /
It is preferably 30 (weight ratio).

In the resin composition of the present invention, the compounding ratio of the α-olefin-unsaturated carboxylic acid copolymer ionomer resin (a) and the thermoplastic elastomer composition (b) is such that the α-olefin-unsaturated carboxylic acid It is necessary that the thermoplastic elastomer composition (b) is in the range of 5 to 200 parts by weight based on 100 parts by weight of the copolymer ionomer resin (a). The blending ratio of the thermoplastic elastomer composition (b) to 100 parts by weight of the α-olefin-unsaturated carboxylic acid copolymer ionomer resin (a) is 2
When the amount exceeds 00 parts by weight, the molded article obtained from the resin composition becomes too soft, and the rebound resilience is impaired. On the other hand, α-
If the blending ratio of the thermoplastic elastomer composition (b) to 100 parts by weight of the olefin-unsaturated carboxylic acid copolymer ionomer resin (a) is less than 5 parts by weight, the flexibility of a molded article obtained from the resin composition is low. It will be inferior. The mixing ratio of both is based on 100 parts by weight of the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (a).
The thermoplastic elastomer composition (b) is preferably in the range of 7 to 150 parts by weight, more preferably in the range of 10 to 100 parts by weight.

The resin composition of the present invention may contain a styrene resin, a polyolefin resin, a polyoxymethylene resin, a polyphenylene ether resin and the like as long as the properties are not impaired. Further, a plasticizer such as process oil, low molecular weight polyethylene, or polyethylene glycol can also be blended. In addition, an inorganic filler can be added to the resin composition of the present invention. Specific examples of such an inorganic filler include, for example, talc, calcium carbonate, kaolin, titanium oxide and the like.

Further, the resin composition of the present invention may contain, for the purpose of modifying it, glass fiber, carbon fiber, heat aging inhibitor, light stabilizer, antistatic agent, release agent, flame retardant, foaming agent, Pigments, dyes, brighteners and the like can also be added.

The resin composition of the present invention is prepared by first preparing a thermoplastic elastomer composition (b) and then preparing an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (a).
And a kneading machine such as a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll. At this time, after the pellet-like thermoplastic elastomer composition (b) is once obtained from the block copolymer and the acrylic resin, it is kneaded with the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (a). Desirably, if desired, the block copolymer and the acrylic resin are kneaded with a single-screw extruder, a twin-screw extruder, or the like to obtain a thermoplastic elastomer composition (b), and then the α-olefin is subjected to side feed. -An unsaturated carboxylic acid copolymer-based ionomer resin (a) may be added and kneaded.

The resin composition of the present invention thus obtained is prepared by injection molding, blow molding, press molding, extrusion molding,
It can be molded by any molding method such as calender molding.

Since the resin composition of the present invention gives a molded article having sufficient rebound resilience and excellent flexibility, it can be utilized for various applications by utilizing such features. Specifically, automobile parts such as body panels and side seals, sports goods such as golf balls and ski shoes, food packaging materials, medical supplies such as syringe gaskets,
It can be used for leisure goods, daily necessities, toy goods, etc.

[0028]

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

In the following Reference Examples, the number average molecular weight is the molecular weight in terms of polystyrene by GPC measurement, the hydrogenation ratio is measured by ¹ H-NMR method, and the glass transition temperature and heat of crystal fusion are DSC. (Differential heat measurement).

In the following Examples and Comparative Examples, the physical properties of the obtained resin compositions were evaluated by the following methods. (Hardness) It was measured according to the method described in ASTM D-2240. That is, a sheet-like test piece (11 cm
× 11 cm × 0.2 cm) and measured using an ASTM D hardness tester. (Rebound resilience) It was measured according to the method described in JIS K-6301. The test temperature is 25 ° C.

Reference Example (Preparation of Thermoplastic Elastomer Composition) In a pressure vessel equipped with a stirrer, 50 kg of cyclohexane, 1650 g of sufficiently dehydrated styrene and 250 g of sec-butyllithium cyclohexane solution (10% by weight) were added.
And polymerized at 60 ° C. for 60 minutes.
Add 700 g for 60 minutes, then add 1650 g of styrene
Was added and polymerized for 60 minutes to synthesize a styrene-isoprene-styrene type block copolymer. The obtained block copolymer had a styrene content of 33% by weight and a number average molecular weight of 35,000. In a cyclohexane solution of this block copolymer, 1% by weight based on the block copolymer
Was added under a hydrogen atmosphere of 50 kg / cm ² to obtain a block copolymer 1 having a hydrogenation ratio of 90%. Olefinic polymer part of the obtained block copolymer 1 (hydrogenated polyisoprene block)
Has a glass transition temperature of -55 ° C and a heat of fusion of 0.1 ca.
It was less than 1 / g. Further, according to ASTM D-1238, the melt flow index of the block copolymer 1 measured at 200 ° C. under a load of 2160 g was 28 g.
/ 10 minutes. This block copolymer 1 and an acrylic resin [PARAPET G (trade name), manufactured by Kuraray Co., Ltd.]
The latter is 60/40 (weight ratio), and 200
The mixture was kneaded at 200 ° C. and 200 rpm to obtain a pellet (thermoplastic elastomer composition 1). Further, by the same operation, the block copolymer 1 and the acrylic resin were kneaded at a ratio of the former / the latter = 40/60 (weight ratio) to obtain pellets (thermoplastic elastomer composition 2).

Examples 1 and 2 Himilan 1652 (trade name, manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was used as an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin. Each of the thermoplastic elastomer compositions was blended at the ratio shown in Table 1 and melt-mixed at a barrel temperature of 230 ° C. using a twin-screw extruder to obtain a resin composition. From the obtained resin composition, a test piece having a predetermined shape was produced at a molding temperature (barrel temperature) of 230 ° C. using an injection molding machine, and various physical properties were evaluated. The results are shown in Table 1.

Comparative Example 1 α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin [Himilan 1652 (trade name, manufactured by Du Pont-Mitsui Polychemical Co., Ltd.)] and the block copolymer 1 obtained in Reference Example Were blended in the proportions shown in Table 1 and melt-mixed using a twin-screw extruder at a barrel temperature of 230 ° C. to obtain a resin composition from the obtained resin composition, at a molding temperature (barrel temperature) of 230 ° C. A test piece having a predetermined shape was prepared by using an injection molding machine and evaluated for various physical properties, and the results are shown in Table 1.

Comparative Example 2 From an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (Himilan 1652), a molding temperature of 230
Test specimens having a predetermined shape were prepared using an injection molding machine at ℃, and various physical properties were evaluated. The results are shown in Table 1.

Reference Example Injection molding machine at a molding temperature of 230 ° C. from α-olefin-unsaturated carboxylic acid copolymer type ionomer resin having low hardness [Himilan 1557 (trade name, manufactured by DuPont-Mitsui Polychemicals)]. A test piece having a predetermined shape was prepared using the method described above, and various physical properties were evaluated.

[0036]

[Table 1]

[0037]

According to the present invention, a resin composition having flexibility is provided without impairing the excellent properties of an ionomer resin such as sufficient rebound resilience, toughness, abrasion resistance and oil resistance. You.

Claims (1)

[Claims] (1) 100 parts by weight of an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin, (b) at least one polymer block A comprising a vinyl aromatic compound, and an olefinic polymer. Having a glass transition temperature of −20 ° C. or less and a heat of crystal fusion of 8 cal /
g or less, and the content of the vinyl aromatic compound is in the range of 5 to 50% by weight,
200 ° C., load 21 according to ASTM D-1238
Thermoplastic elastomer composition 5-200 containing a block copolymer having a melt flow index of 5 to 30 as measured at 60 g and an acrylic resin in a weight ratio of the former / the latter = 30/70 to 90/10. A resin composition containing parts by weight.