JPH0940826A - Resin composition - Google Patents

Abstract

(57) Abstract: (a) 100 parts by weight of an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin, and (b) at least a polymer block (A) mainly containing a vinyl aromatic compound. 1 and at least one polymer block (B) consisting of an olefinic elastomer, having a glass transition temperature of −20 ° C. or lower and a heat of crystal fusion of 8 cal / g or lower, and a content of a vinyl aromatic compound. Is in the range of 5 to 50% by weight, and ASTMD-12
38, a resin composition containing 5 to 200 parts by weight of a block copolymer having a melt flow index of 5 to 30 when measured at 200 ° C. and a load of 2160 g. [Effect] A molded product having sufficient flexibility and excellent in toughness, wear resistance, oil resistance, weather resistance and the like is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition, and more particularly to a resin composition containing an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin and a vinyl aromatic compound-olefinic compound block copolymer. Regarding things.

[0002]

2. Description of the Related Art Conventionally, α-olefin-unsaturated carboxylic acid copolymer type ionomer resins have been used for automobile parts, golf balls, ski shoes, etc. by taking advantage of their excellent toughness, abrasion resistance and oil resistance. There is. However, a molded body using such an ionomer resin generally has a high hardness, and there is a problem that a shot feeling is poor in a golf ball, for example. Therefore, it is desired to impart flexibility to the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin without impairing toughness, abrasion resistance, oil resistance and the like.

As an attempt to give flexibility to an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin,
Japanese Patent Application Laid-Open No. 1-308577 proposes to blend a soft ionomer resin, that is, a salt of a terpolymer containing an olefin compound, an unsaturated monocarboxylic acid and an unsaturated monomer such as an acrylic ester, and JP-A-5-345051 proposes blending a saponified product of a specific ethylene-ethyl acrylate copolymer. Further, US Pat.
No. 6,545 proposes blending 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 type ionomer resin composition described above provides a molded article having excellent flexibility, but the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin is used. 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 its compatibility with. In addition, α-olefin-
When an unmodified thermoplastic elastomer is blended with an unsaturated carboxylic acid copolymer-based ionomer resin, the compatibility between the two is not sufficient, and the resulting molded article is described as having insufficient durability such as impact resistance. ing.

The present invention, therefore, has an ionomer resin composition of an α-olefin-unsaturated carboxylic acid copolymer which gives a molded product having sufficient flexibility and excellent toughness, abrasion resistance, oil resistance and weather resistance. The challenge is to provide new things.

[0006]

The present inventors have found that a specific vinyl aromatic compound-olefin compound block copolymer has excellent compatibility with an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin. However, it was found that a resin composition capable of solving the above problems can be obtained by blending the 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, (b) at least one polymer block (A) mainly composed of a vinyl aromatic compound, and an olefinic elastomer, and having a glass transition temperature of -2.
There is at least one polymer block (B) having a heat of fusion of crystal of 8 cal / g or less at 0 ° C. or less, and the content of the vinyl aromatic compound is in the range of 5 to 50% by weight.
According to TMD-1238, 200 ° C, load 2160g
Melt flow index is 5 when measured at
It is a resin composition containing 5 to 200 parts by weight of a block copolymer of 30 to 30 parts by weight.

The α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) used in the present invention
Is a copolymer of α-olefins such as ethylene and propylene and unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and maleic acid, or copolymers of α-olefins, unsaturated carboxylic acids and their esters. It means a resin in which at least a part of the combined carboxyl groups forms a salt with a metal cation such as sodium, potassium, lithium, copper, magnesium, zinc, or aluminum. In the present invention, those known as such an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin can be used without particular limitation, and for example, "SURLYN" manufactured by DuPont.
(Trade name), “HIMILAN” (trade name) manufactured by Mitsui DuPont Polychemical Co., Ltd., “IOTEK” (trade name) manufactured by Exxon Co., etc. are preferably used. .

The block copolymer (b) used in the present invention is composed of at least one polymer block (A) mainly containing a vinyl aromatic compound and an olefinic elastomer and has a glass transition temperature of-. 20 ° C
Having at least one polymer block (B) having a heat of fusion of crystal of 8 cal / g or less, the content of the vinyl aromatic compound is in the range of 5 to 50% by weight, and A
200 ° C, load 216 according to STM D-1238
It is a block copolymer having a melt flow index of 5 to 30 when measured at 0 g.

Examples of the vinyl aromatic compound which constitutes the above block copolymer (b) include styrene and α-
Methylstyrene, o-, m- or p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like can be mentioned. 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 (b) must be in the range of 5 to 50% by weight. If the content of the vinyl aromatic compound is out of this range, the rubber elasticity of the block copolymer (b) will not be sufficient and the flexibility of the molded product obtained from the resin composition will be impaired. The content of the vinyl aromatic compound in the block copolymer (b) is preferably in the range of 10 to 35% by weight.

On the other hand, the polymer block (B) composed of an olefinic elastomer is a soft segment of the block copolymer (b) and has a glass transition temperature of -20 ° C.
The heat of fusion of crystal is required to be 8 cal / g or less. When the glass transition temperature of the polymer block (B) exceeds −20 ° C., sufficient flexibility is not imparted to the molded product obtained from the resin composition, and the heat of crystal fusion of the polymer block (B) is If it exceeds 8 cal / g, the flexibility of the molded article at low temperature becomes poor.

Examples of the polymer block (B) composed of an olefinic elastomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and 1,3-hexadiene. In addition to a hydrogenated product of a polymer of these mixtures, a polymer of isobutylene or α-olefin and the like can be mentioned.

A preferred example of the polymer block (B) consisting of an olefinic elastomer is 1,3-butadiene,
It is a hydrogenated product of a polymer of isoprene or a mixture thereof. When the polymer block (B) is a hydrogenated product of a polymer of 1,3-butadiene, its structure is ethylene-
It becomes a butylene random copolymer. When the polymer block (B) is a hydrogenated product of a polymer of isoprene, its structure is an ethylene / propylene alternating copolymer, and the polymer block (B) is a mixture of 1,3-butadiene and isoprene. In the case of the hydrogenated product of the polymer (1), the structure thereof is an ethylene-ethylene / propylene random copolymer.

When the polymer block (B) is a hydrogenated product of a polymer of a conjugated diene, it is preferable that at least 70% of the aliphatic double bond based on the conjugated diene is hydrogenated, and a vinyl bond is contained. The amount is preferably 50 mol% or less. When the hydrogenation rate of the aliphatic double bond in the polymer block (B) is less than 70%, the heat aging resistance of the molded product obtained from the resin composition may be insufficient. Further, if the vinyl bond content of the polymer block (B) exceeds 50 mol%, the low temperature characteristics of the molded product obtained from the resin composition may be inferior.

The melt viscosity of the block copolymer (b) is AS
200 ° C, load 2160 according to TM D-1238
The melt flow index, measured in g, must be 5-30. When the melt flow index of the block copolymer (b) is less than 5, the moldability of the resin composition is not sufficient, and when the melt flow index exceeds 30, the resin composition exhibits stickiness. Tends to show.

The molecular weight of the block copolymer (b) is not particularly limited, but usually 5,000 to 100,000.
It is within the range of 0.

The molecular structure of the block copolymer (b) may be linear, branched or any combination thereof. Further, the block copolymer (b) is
A substituent such as a hydroxyl group, a carboxyl group, an epoxy group, an amino group, or a halogen may be present at the molecular end or the molecular chain as long as the characteristics are not lost.

As a method for obtaining the block copolymer (b), a known method can be used without particular limitation, and a method of hydrogenating the polymer obtained by anionic polymerization,
Ionic polymerization method such as cationic polymerization, Ziegler polymerization method,
Any method such as a single-site polymerization method or a radical polymerization method may be used.

In the resin composition of the present invention, the blending ratio of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) and the block copolymer (b) is such that the α-olefin-unsaturated carboxylic acid copolymer It is necessary that the amount of the block copolymer (b) is in the range of 5 to 200 parts by weight with respect to 100 parts by weight of the polymer type ionomer resin (a). When the blending ratio of the block copolymer (b) to 100 parts by weight of the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (a) exceeds 200 parts by weight, the oil resistance of the molded product obtained from the resin composition is increased. It will be inferior.
On the other hand, when the blending ratio of the block copolymer (b) to 100 parts by weight of the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (a) is less than 5 parts by weight, a molded product obtained from the resin composition is obtained. It will be less flexible. 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 block copolymer (b) is preferably in the range of 7 to 150 parts by weight, more preferably 10 to 100 parts by weight.

The resin composition of the present invention is a modified product of the above block copolymer (b), as long as its characteristics are not impaired.
A styrene resin, a polyolefin resin, a polyoxymethylene resin, a polyphenylene ether resin, etc. can be blended. Further, a plasticizer such as process oil, low molecular weight polyethylene, or polyethylene glycol can also be blended. Further, an inorganic filler may be added for the purpose of cost reduction. 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, for the purpose of modification thereof, includes glass fibers, carbon fibers, heat aging inhibitors, light stabilizers, antistatic agents, mold release agents, flame retardants, foaming agents,
Pigments, dyes, brighteners and the like can be added.

The resin composition of the present invention can be prepared by using a kneader such as a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll.

The resin composition thus obtained can be molded by any molding method such as injection molding, blow molding, press molding, extrusion molding and calender molding.

The resin composition of the present invention provides a molded product having sufficient flexibility, excellent toughness, wear resistance, oil resistance, weather resistance, etc. Can be used. Specifically, body panels, automobile parts such as side seals, golf balls, sports goods such as ski shoes, food packaging materials, medical supplies such as syringe gaskets, leisure goods, daily necessities,
It can be used for toy supplies.

[0026]

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 polystyrene equivalent molecular weight by the GPC method, the hydrogenation rate and the vinyl bond content are those measured by the NMR method, and the glass transition temperature and crystal melting The heat is obtained by DSC.

In the following Examples and Comparative Examples, the physical properties of the obtained resin compositions were evaluated by the following methods.

(Moldability) Injection molding was carried out at 230 ° C.
Sheet-shaped compact (11 cm x 11 cm x 0.2 cm)
Was observed, and the surface of the obtained molded product was observed, and based on the presence / absence of flow marks, evaluation was made according to the following criteria. ○ ・ ・ No flow mark is observed. △: Presence of flow mark is slightly recognized. × ... There are many flow marks.

(Hardness) The hardness was measured according to the method described in JIS K6301. That is, a sheet-shaped test piece (11 cm × 11 cm × 0.2 cm) was prepared and
It measured using the A hardness meter.

(Breaking strength) The breaking strength was measured according to the method described in JIS K6301. That is, a dumbbell-shaped test piece specified in JIS No. 3 was prepared, a tensile test was performed at a tensile speed of 5 cm / min using an Instron universal testing machine, and the breaking strength (kg / cm ² ) was measured.

(Oil resistance) Strip-shaped test piece (1 cm × 6 c
m × 0.3 cm), the test piece was dipped in JIS No. 1 oil, the weight of the test piece before and after the measurement was measured, and the degree of swelling (%) was calculated according to the following formula to give an index of oil resistance. did.

[0033]

[Equation 1]

(Impact resistance) In accordance with the method described in JIS K7110, a strip-shaped test piece with a notch (1 cm
(× 6 cm × 0.3 cm), an Izod impact resistance test was carried out at −20 ° C. to determine the impact strength (kg · cm / cm).

Reference Example 1 (Production of Block Copolymer) 50 kg of cyclohexane, 1650 g of fully dehydrated styrene and 250 g of sec-butyllithium (10% by weight, cyclohexane solution) in a pressure vessel equipped with a stirrer.
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. 1% by weight in this polymer solution
/ Add 50 mg of palladium catalyst
Hydrogenation reaction is performed in a hydrogen atmosphere of / cm ^{2 and} the hydrogenation rate is 90
% Block copolymer 1 was obtained. Table 1 shows the glass transition temperature and heat of crystal fusion of the olefinic elastomer portion of the obtained block copolymer 1. Also, ASTM D-1
Table 1 also shows the melt flow index values of the block copolymer 1 measured according to 238 at 200 ° C. and a load of 2160 g.

Reference Example 2 (Production of Block Copolymer) 50 kg of cyclohexane, 1250 g of sufficiently dehydrated styrene and 240 g of sec-butyllithium (10% by weight, cyclohexane solution) in a pressure vessel equipped with a stirrer.
And polymerized at 60 ° C. for 60 minutes.
Butadiene = 50/50 weight ratio mixed monomer 750
0 g was added for 60 minutes, and then 1250 g of styrene was added for polymerization for 60 minutes to synthesize a styrene-isoprene / 1,3-butadiene-styrene type block copolymer. The obtained block copolymer had a styrene content of 25% by weight and a number average molecular weight of 41,000. A hydrogenation reaction was carried out in the same manner as in Reference Example 1 to obtain a block copolymer 2 having a hydrogenation rate of 98%. Table 1 shows the glass transition temperature and the heat of crystal fusion of the olefinic elastomer portion of the obtained block copolymer 2. Table 1 also shows the melt flow index values of the block copolymer 2 measured at 200 ° C and a load of 2160 g according to ASTM D-1238.

Reference Example 3 (Production of Block Copolymer) 50 kg of cyclohexane, 2000 g of fully dehydrated styrene and 190 g of sec-butyllithium (10% by weight, cyclohexane solution) in a pressure vessel equipped with a stirrer.
Was added and polymerized at 60 ° C. for 60 minutes, then 230 g of tetrahydrofuran was added, and 1,3-butadiene was added to 600
Add 0 g and polymerize for 60 minutes, 2000 g of styrene
Was added and polymerized for 60 minutes to synthesize a styrene-butadiene-styrene block copolymer. The obtained block copolymer had a styrene content of 40% by weight and a number average molecular weight of 55,000. A hydrogenation reaction was carried out in the same manner as in Reference Example 1 to obtain a block copolymer 3 having a hydrogenation rate of 98%.
Table 1 shows the glass transition temperature and heat of crystal fusion of the olefinic elastomer portion of the obtained block copolymer 3. Table 1 also shows the melt flow index values of the block copolymer 3 measured at 200 ° C. and a load of 2160 g according to ASTM D-1238.

Reference Example 4 (Production of Block Copolymer) 50 kg of cyclohexane, 1650 g of fully dehydrated styrene and 120 g of sec-butyllithium (10% by weight, cyclohexane solution) in a pressure vessel equipped with a stirrer.
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 75,000. A hydrogenation reaction was carried out in the same manner as in Reference Example 1 to obtain a block copolymer 4 having a hydrogenation rate of 95%.
Table 1 shows the glass transition temperature and heat of crystal fusion of the olefinic elastomer portion of the obtained block copolymer 4. Table 1 also shows the melt flow index values of the block copolymer 4 measured at 200 ° C. and a load of 2160 g according to ASTM D-1238.

[0039]

[Table 1]

Examples 1 to 6 and Comparative Examples 1 to 3 Hi-Milan 1605 (trade name, manufactured by Mitsui-DuPont Polychemical Co., Ltd.) was used as an ionomer resin of α-olefin-unsaturated carboxylic acid copolymer and used as a reference. Examples 1-
4 types of block copolymers obtained in Example 4 and Table 2
The resin composition was obtained by blending in the proportions shown in (1) and melt-blended at 230 ° C. in a twin-screw extruder. A test piece having a predetermined shape was prepared from the obtained resin composition at a molding temperature of 230 ° C. by using an injection molding machine, and various physical properties were evaluated. Table 2 shows the results.

[0041]

[Table 2]

From the results shown in Table 2, it is clear that the resin composition of the present invention is excellent in moldability, has sufficient flexibility, and gives a molded product excellent in toughness and oil resistance.

[0043]

The resin composition provided by the present invention comprises:
A molded product having sufficient flexibility and excellent toughness, abrasion resistance, oil resistance, weather resistance and the like is provided.

Claims (1)

[Claims] 1. An α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin (100 parts by weight), and (b) at least one polymer block (A) mainly containing a vinyl aromatic compound, and an olefin. Having at least one polymer block (B) having a glass transition temperature of −20 ° C. or less and a crystal fusion heat of 8 cal / g or less and a vinyl aromatic compound content of 5 to 50 wt. % Range, ASTM D-12
38, a resin composition containing 5 to 200 parts by weight of a block copolymer having a melt flow index of 5 to 30 when measured at 200 ° C. and a load of 2160 g.