JPH09124861A - Thermoplastic resin composition - Google Patents

Abstract

(57) Abstract: At least a polymer block A composed of (a) an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin and (b) a polybutadiene having a 1,2 bond content of 20% or less. A polymer block B composed of one and a conjugated diene compound (provided that the polymer block B is a polymer block composed of polybutadiene, 1, 2
(Bond content is 25% or more) containing a hydrogenated block copolymer obtained by hydrogenating a block copolymer having at least one (a) / (b) = 9.
The thermoplastic resin composition which is 5/5 to 5/95 (weight ratio). [Effect] A molded product having sufficient flexibility and having excellent mechanical strength, abrasion resistance, oil resistance and the like is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an α-olefin
The present invention relates to a thermoplastic resin composition containing an unsaturated carboxylic acid copolymer type ionomer resin and a specific hydrogenated block copolymer.

[0002]

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

The following methods (1) to (2) have been proposed as an attempt to impart flexibility to the ionomer resin of the .alpha.-olefin-unsaturated carboxylic acid copolymer. A method of blending a soft ionomer resin, that is, a salt of a ternary copolymer composed of an olefin compound, an unsaturated monocarboxylic acid and an unsaturated monomer such as an acrylic acid ester (see JP-A-1-308577). A method of blending a saponified product of a specific ethylene-ethyl acrylate copolymer (see JP-A-5-345051). A method of blending a vinyl aromatic compound-conjugated diene compound block copolymer modified with maleic anhydride or the like (see US Pat. No. 4,986,545).

[0004]

However, a molded article obtained from the above-mentioned and α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin composition is sufficiently satisfactory in flexibility and oil resistance. is not. Further, although the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin composition described above gives a molded article excellent in flexibility, the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin is used. It is said that satisfactory results can be obtained only when a block copolymer modified with maleic anhydride or the like is used because of its compatibility with. In the above, when the unmodified vinyl aromatic compound-conjugated diene compound block copolymer is blended with the α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin, the compatibility between the two is not sufficient, and It is described that the obtained molded article does not have sufficient durability such as impact resistance. Further, in this case, the properties of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin such as mechanical strength, abrasion resistance and oil resistance are impaired.

Therefore, the present invention provides an α-olefin-unsaturated carboxylic acid copolymer-based ionomer resin which provides a molded product having sufficient flexibility and excellent toughness, mechanical strength, abrasion resistance, oil resistance and the like. It is an object to newly provide a composition.

[0006]

The present inventors have found that a specific hydrogenated block copolymer has excellent compatibility with an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin, and they are blended with each other. As a result, it was found that a resin composition capable of solving the above problems can be obtained, and as a result of further study, the present invention has been completed.

That is, at least one polymer block A comprising (a) an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin and (b) a polybutadiene having a 1,2 bond content of 20% or less is used in the present invention. Block copolymer having at least one polymer block B composed of 1 and a conjugated diene compound (provided that the polymer block B is a polymer block composed of polybutadiene, the 1,2 bond content is 25% or more). Is a hydrogenated block copolymer, and the ratio of the two is (a) / (b) = 95/5 to 5/95 (weight ratio).

The α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) used in the present invention
And, 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 α-olefins, unsaturated carboxylic acids and esters thereof. Means a resin in which at least a part of the carboxyl group of the copolymer is a salt with a metal cation such as sodium, potassium, lithium, copper, magnesium, zinc or aluminum.

In the present invention, known ones as such an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin can be used without particular limitation.
"SURLYN" (brand name) manufactured by DuPont, "HIMILAN" (brand name) manufactured by DuPont Mitsui Polychemicals, "IOTEC" (brand name) manufactured by Exxon, etc. A commercially available product is preferably used. The α-olefin-unsaturated carboxylic acid copolymer ionomer resin (a) may be used alone or in combination of two or more.

The hydrogenated block copolymer (b) used in the present invention contains at least one polymer block A composed of polybutadiene having a 1,2 bond content of 20% or less and a polymer composed of a conjugated diene compound. It is obtained by hydrogenating a block copolymer having at least one united block B.

The polymer block A must have a 1,2 bond content of 20% or less. When the 1,2 bond content in the polymer block A exceeds 20%, the oil resistance of the molded product obtained from the thermoplastic resin composition is impaired.

On the other hand, the polymer block B is composed of a conjugated diene compound, and examples of the conjugated diene compound include butadiene, isoprene, 2,3-dimethyl 1,3-butadiene, 1,3-pentadiene, 1,
3-hexadiene etc. are mentioned. The conjugated diene compounds may be used alone or in combination of two or more.
Among these, isoprene, butadiene, and a mixture of isoprene and butadiene mixed in a ratio of 20 to 80/80 to 20 (weight ratio) are preferable.

The microstructure of the polymer block B is not particularly limited. However, when the polymer block B is a polymer block made of polybutadiene, the content of 1,2 bonds is preferably 25% or more and 90% or less.

The weight ratio of the polymer block A to the polymer block B is preferably A / B = 10/90 to 90/10, and more preferably A / B = 20/80 to 85/15. Specific examples of the block copolymer before hydrogenation having at least one polymer block A and at least one polymer block B are shown below.

(B-I) n, (B-I) n-B, [B- (I / B)] n, [B- (I / B)] n-B, (BVB) n, (B−V · B) n−B, (B−V · I) n, (B−V · I) n−B, [B−V · (I / B)] n, [B−V -(I / B)] n-B.

(In the above formula, B has a 1,2 bond content of 20.
% Of a polybutadiene polymer block, I
Is an isoprene polymer block having a content of 1,2 bonds and 3,4 bonds (hereinafter collectively referred to as vinyl bonds) of 25% or less, and (I / B) is a mixture of isoprene and butadiene, A polymer block having a vinyl bond content of 25% or less, V.B is a butadiene polymer block having a 1,2-bond content of 25 to 90%, and V.I.
Represents a polymer block having a vinyl bond content of 25 to 90%, V · (I / B) represents a polymer block composed of a mixture of isoprene and butadiene, and having a vinyl bond content of 25 to 90%, n represents an integer of 1 to 5. )

When the above block copolymer contains two or more polymer blocks A, each polymer block A may be the same or different in molecular weight, microstructure and the like of the polymer blocks. May be. Further, even when the above block copolymer contains two or more polymer blocks B, each polymer block B may be the same, or the type and composition of the conjugated diene compound, which is a constituent, and the molecule. It may be different in the distribution of the conjugated diene compound in the chain, the molecular weight of the polymer block, the microstructure and the like.

The hydrogenated block copolymer (b) obtained by hydrogenating the above block copolymer preferably has a number average molecular weight of 20,000 to 500,000 and a molecular weight distribution. It is preferable that (ratio of weight average molecular weight to number average molecular weight) is in the range of 1.05 to 10. The molecular structure of the hydrogenated block copolymer (b) is
It may be linear, branched, radial or any combination thereof.

As a method for producing the hydrogenated block copolymer (b), known methods can be used without particular limitation.
Examples thereof include a method of obtaining a block copolymer from butadiene and a conjugated diene compound by anionic living polymerization, radical polymerization, stereoregular polymerization, and the like, and then hydrogenating the obtained block copolymer.

As a specific example, first, butadiene and the above conjugated diene are sequentially polymerized in an inert hydrocarbon solvent such as benzene, toluene, hexane, and cyclohexane using an organolithium compound such as butyllithium as a catalyst. To obtain a block copolymer. At this time, a branched or radial block copolymer can be obtained by using a polyfunctional coupling agent such as carbon tetrachloride or silicon tetrachloride.

Next, the block copolymer obtained above is hydrogenated in the presence of a hydrogenation catalyst in an inert organic solvent according to the method described in JP-B-42-8704, for example. Hydrogenated by. The hydrogenation rate is
It is not particularly limited and may be appropriately adjusted depending on the required physical properties, but when heat resistance and weather resistance are important, it is preferably 50% or more, and more preferably 70% or more. The hydrogenation rate of the block copolymer is measured by instrumental analysis such as nuclear magnetic resonance absorption spectrum (NMR) and infrared absorption spectrum (IR), and chemical analysis such as iodometric titration method in the hydrogenated block copolymer (b). The ratio of the carbon-carbon double bond can be measured and calculated from the measured value.

The hydrogenated block copolymer (b) has a carboxyl group, an acid anhydride group, a hydroxyl group, an epoxy group, at the molecular end or in the molecular chain, as long as the gist of the present invention is not impaired. It may have a substituent such as an amino group and a halogen atom.

In the thermoplastic resin composition of the present invention, α
-The ratio of the olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) and the hydrogenated block copolymer (b) is (a) / (b) = 95/5 to 5/95 (weight ratio). Must be within range. The proportion of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) is based on the total weight of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) and the hydrogenated block copolymer (b). If it exceeds 95% by weight, the flexibility of the molded product obtained from the thermoplastic resin composition will be poor. On the other hand, the proportion of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) is the total weight of the α-olefin-unsaturated carboxylic acid copolymer type ionomer resin (a) and the hydrogenated block copolymer (b). On the other hand, if it is less than 5% by weight, the mechanical strength and oil resistance of the molded product obtained from the thermoplastic resin composition will be poor. The ratio of both is (a) / (b) =
It is more preferably within the range of 90/10 to 10/90 (weight ratio).

The thermoplastic resin composition of the present invention contains a modified product of the hydrogenated block copolymer (b), a styrene resin, a polyolefin resin, a polyoxymethylene resin, a polyphenylene ether resin, as long as its characteristics are not impaired. Etc. can be blended. Further, a plasticizer such as process oil, low molecular weight polyethylene, or polyethylene glycol can also be blended. Furthermore, an inorganic filler can be added for the purpose of cost reduction. Specific examples of such an inorganic filler include talc, calcium carbonate,
Examples thereof include kaolin and titanium oxide.

Further, the thermoplastic resin composition of the present invention comprises
Fillers such as glass fiber, carbon fiber, heat aging inhibitor, light stabilizer, antistatic agent, mold release agent, flame retardant, foaming agent, pigment, dye, whitening agent, etc. are added for the purpose of modification. can do.

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

The thermoplastic resin composition thus obtained can be molded by various conventionally known molding methods such as injection molding, blow molding, press molding, extrusion molding and calender molding.

The thermoplastic resin composition of the present invention provides a molded article having sufficient flexibility and excellent mechanical strength, abrasion resistance, oil resistance and the like.
For example, it can be used in various fields such as automobile parts such as body panels and side seals, sports products such as golf balls and ski shoes, food packaging materials, medical products such as syringe gaskets, leisure products, daily necessities and toy products.

[0029]

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 of the polymer is the molecular weight in terms of polystyrene by the GPC method, and the hydrogenation rate and 1,2 bond content are measured by ¹ H-NMR.

In the following Examples and Comparative Examples, the hardness, breaking strength and oil resistance of molded articles obtained from the thermoplastic resin composition were measured by the following methods.

(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. The hardness measurement is an index of flexibility.

(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, and a tensile test was performed at room temperature at a tensile speed of 5 cm / min using an Instron universal testing machine to measure the breaking strength (kg / cm ² ). did. The measured value of breaking strength is an index of mechanical strength.

(Oil resistance) A strip-shaped test piece (1 cm × 6 c
m × 0.3 cm), the test piece was immersed in JIS No. 1 oil for 4 days, the weight of the test piece before and after the measurement was measured, and the swelling degree (%) was determined according to the following formula to determine the oil resistance. It was used as an index.

[0034]

(Equation 1)

Reference Example 1 (Production of Hydrogenated Block Copolymer 1) 50 kg of n-hexane, 1500 g of sufficiently dehydrated butadiene and n-butyllithium (10% by weight, n-hexane solution) were placed in a pressure vessel equipped with a stirrer. Add 270 g and polymerize at 60 ° C. for 60 minutes, then add isoprene 700
0 g was added for 60 minutes, and 1500 g of butadiene was added for polymerization for 60 minutes to obtain a triblock copolymer.
Next, this block copolymer was hydrogenated in an n-hexane solution using 1 wt% / polymer of cobalt naphthenate and a triethylaluminum catalyst under a hydrogen atmosphere of 10 kg / cm ² , and A hydrogenated block copolymer 1 shown in was obtained.

Reference Example 2 (Production of hydrogenated block copolymer 2) 50 kg of n-hexane, 2500 g of sufficiently dehydrated butadiene and n-butyllithium (10% by weight, n-hexane solution) were placed in a pressure vessel equipped with a stirrer. 140g was added and polymerized at 60 ° C for 60 minutes, then isoprene 750
0 g was added and the mixture was polymerized for 60 minutes to obtain a diblock copolymer. Next, this block copolymer was added to an n-hexane solution,
Using cobalt naphthenate and triethylaluminum catalyst in an amount of 1% by weight / polymer, 10 kg / cm ²
Hydrogenation was carried out under the hydrogen atmosphere described above to obtain a hydrogenated block copolymer 2 shown in Table 1.

Reference Example 3 (Production of Hydrogenated Block Copolymer 3) In a pressure vessel equipped with a stirrer, 50 kg of n-hexane, 1000 g of sufficiently dehydrated butadiene and n-butyllithium (10% by weight, n-hexane solution). Add 110 g and polymerize at 60 ° C. for 60 minutes, then mix with isoprene / butadiene [isoprene / butadiene = 60/40
(Weight ratio)] 8000 g was added for 60 minutes, and 1000 g of butadiene was further added for polymerization for 60 minutes to obtain a triblock copolymer. Next, this block copolymer was prepared in an n-hexane solution using 1 wt% / polymer of cobalt naphthenate and a triethylaluminum catalyst to prepare 1
Hydrogen was added in a hydrogen atmosphere of 0 kg / cm ² , and
The hydrogenated block copolymer 3 shown in was obtained.

[0038]

[Table 1]

Examples 1 to 3 Using Hi-Milan 1605 (trade name, manufactured by Mitsui-DuPont Polychemical Co., Ltd.) as the ionomer resin (a) of α-olefin-unsaturated carboxylic acid copolymer, Reference Examples 1 to 1 The three types of hydrogenated block copolymers (b) obtained in No. 3 were blended in the proportions shown in Table 2 and melt-mixed at 230 ° C. in a twin-screw extruder to obtain a thermoplastic resin composition. A test piece having a predetermined shape was prepared from the obtained thermoplastic resin composition at 230 ° C., and the hardness, breaking strength and oil resistance were measured. Table 2 shows the results.

[0040]

[Table 2]

[0041]

EFFECT OF THE INVENTION The thermoplastic resin composition provided by the present invention has sufficient flexibility and mechanical strength,
It gives a molded article having excellent wear resistance and oil resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromichi Nakada 36 Higashiwada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture Kuraray Co., Ltd. (72) Koichi Wada 36 Higashiwada, Kamisu-cho, Kashima-gun Ibaraki Prefecture

Claims (1)

[Claims] 1. At least one polymer block A comprising (a) an α-olefin-unsaturated carboxylic acid copolymer type ionomer resin and (b) polybutadiene having a 1,2 bond content of 20% or less and a conjugated diene. A polymer block B composed of a compound (provided that the polymer block B is a polymer block composed of polybutadiene, 1, 2
(Bond content is 25% or more) containing a hydrogenated block copolymer obtained by hydrogenating a block copolymer having at least one (a) / (b) = 9.
The thermoplastic resin composition which is 5/5 to 5/95 (weight ratio).