JPH05230322A - Hydrogenated block copolymer composition - Google Patents

Abstract

PURPOSE:To provide the subject composition good in the flexibility, moldability and scratch resistance by compounding a block copolymer hydrogenated product, a methacrylic resin and a copolymer compatible therewith. CONSTITUTION:The objective hydrogenated block copolymer composition excellent in the moldability and scratch resistance comprises 100 pts.wt. of a resin composition and 0.1-20 pts.wt. of a copolymer (e.g. an olefin-methyl methacrylate copolymer) having units compatible with a methacrylic resin and a hydrogenated block copolymer, respectively, the resin composition comprising 90-20wt.% of the hydrogenated block copolymer and 80-10wt.% of the methacrylic resin, and the hydrogenated block copolymer being obtained by hydrogenating a block copolymer represented by the formula A-(B-A) (1<=n<=5) comprising a terminal polymer block A consisting mainly of at least two vinylic aromatic compounds (e.g. styrene) and an intermediate polymer B consisting mainly of at least one conjugated diene compound (e.g. butadiene).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a predetermined amount of a copolymer containing a hydrogenated block copolymer and a methacrylic resin as main components and having a unit showing compatibility with the methacrylic resin and the hydrogenated block copolymer. A hydrogenated block copolymer composition which can be used as a raw material for various molded articles, which has improved compatibility with each other by addition, and has excellent flexibility, scratch resistance, mechanical strength and molding processability. It is about.

[0002]

2. Description of the Related Art Recently, a thermoplastic elastomer (hereinafter abbreviated as TPE), which is a rubber-like soft material and does not require a vulcanization step and has the same moldability as a thermoplastic resin, is used for automobile parts, home electric appliances, and wire coating , Footwear, toys, miscellaneous goods, etc. However, TPE does not reach the level of vulcanized rubber in terms of quality in the use of vulcanized rubber, which is one of the wide fields of application as a rubber, and therefore its use in the vulcanized rubber field is limited. Styrene-butadiene block polymers and styrene-isoprene block polymers are one of the typical examples of these TPEs. These TPEs are rich in flexibility and have good rubber elasticity at room temperature. It also has excellent moldability, especially injection moldability, but it has double bonds in the polybutadiene block or polyisoprene block in the polymer, so it has excellent heat aging resistance (heat stability) and weather resistance. There's a problem. By hydrogenating the intramolecular double bond of the block copolymer of styrene and a conjugated diene, an elastomer having improved thermal stability and weather resistance can be obtained. However, this hydrogenated product has drawbacks such as insufficient rubber elasticity at high temperature, large deformation under heating and pressurization, and poor scratch resistance, and there is still a problem when it is used for vulcanized rubber.

On the other hand, methacrylic resin has excellent transparency,
It has weather resistance, surface gloss and scratch resistance, but has the drawback of poor impact resistance. Generally, it is difficult to obtain a resin composition having good properties such as scratch resistance, impact resistance, and moldability from a single resin.
A technique called a polymer alloy is used in which two or more kinds of resins capable of compensating for each of the drawbacks are combined. However, the compatibility between each resin is usually poor, and it is difficult to obtain a thermoplastic resin that has the advantages of each resin because it is not possible to form an incompatible micro phase separation structure simply by mixing them. .. As a method for improving the compatibility, a method of adding a compatibilizing agent having an affinity to any of the resins to be combined is generally performed, but in the case of a methacrylic resin and a styrene-based hydrogenated block copolymer, There was no suitable compatibilizer and the improvement effect was insufficient.

[0004]

DISCLOSURE OF THE INVENTION In the present invention, as a result of intensive studies to obtain a compatibilizer having an affinity for both hydrogenated block copolymers and methacrylic resins, methacrylic resin and hydrogenated block copolymers were obtained. In the copolymer having a unit showing compatibility with each other, the compatibility between the hydrogenated block copolymer and the methacrylic resin is significantly improved, and the flexibility is high,
It was found that a material having good scratch resistance, mechanical strength and moldability was obtained, and the present invention was completed.

[0005]

Means for Solving the Problems That is, the present invention comprises a terminal polymer block A mainly containing at least two vinyl aromatic compounds, and an intermediate polymer block B mainly containing at least one conjugated diene compound. Hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of 90-
To 100 parts by weight of a resin composition consisting of 20% by weight and 80 to 10% by weight of a methacrylic resin, 0.1 to 0.1 parts by weight of a copolymer having units compatible with the methacrylic resin and the hydrogenated block copolymer, respectively. The present invention relates to a hydrogenated block copolymer composition containing 20 parts by weight.

The hydrogenated block copolymer used in the present invention comprises a terminal polymer block A mainly containing at least two vinyl aromatic compounds and an intermediate polymer block mainly containing at least one conjugated diene compound. A vinyl aromatic compound having a structure represented by the following general formula, which is obtained by hydrogenating a block copolymer comprising B and
It is a hydrogenated product of a conjugated diene compound block copolymer. A- (BA) _n 1 ≤ n ≤ 5 This hydrogenated block copolymer has a vinyl aromatic compound of 5
-60% by weight, preferably 10-50% by weight. Further, referring to the block structure, the terminal polymer A mainly composed of a vinyl aromatic compound has a vinyl aromatic compound polymer block or a vinyl aromatic compound of 50% by weight. weight%
Having a structure of a copolymer block of a vinyl aromatic compound and a hydrogenated conjugated diene compound, the content of which is more than 70% by weight, and is mainly composed of a hydrogenated conjugated diene compound. The intermediate polymer block B contains a hydrogenated conjugated diene compound polymer block or a hydrogenated conjugated diene compound in an amount of more than 50% by weight, preferably 70% by weight or more, and a hydrogenated conjugated diene compound and vinyl aroma. It has a structure of a copolymer block with a group compound. When there are two or more polymer blocks mainly containing a vinyl aromatic compound and polymer blocks mainly containing a hydrogenated conjugated diene compound, each polymer block may have the same structure or different. It may be a structure.

As the vinyl aromatic compound constituting the hydrogenated block copolymer, for example, one kind or two or more kinds can be selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene and the like. Of these, styrene is preferable. As the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound, for example, one kind or two or more kinds are selected from butadiene, isoprene, 2.3-dimethyl-1.3-butadiene and the like. Among them, butadiene, isoprene and combinations thereof are preferable. The number average molecular weight (Mn) of the hydrogenated block copolymer used in the present invention is 5,000 to 1,000,000, preferably 10,000 to 800,000, more preferably 3
The molecular weight distribution Mw is in the range of 0000 to 500000
/ Mn is 10 or less (Mw: weight average molecular weight). Further, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial or any combination thereof.

The methacrylic resin used in the present invention is not particularly limited and is commercially available, and examples thereof include a copolymerized methacrylic resin obtained by copolymerization with polymethylmethacrylate (PMMA) and styrene. Be done. These may be used alone or in combination of two or more.

In the present invention, the hydrogenated block copolymer (1) and the methacrylic resin (2) are (1) :( 2) =
It is mixed in the range of 90:10 to 20:80 (% by weight). If the blending amount of the methacrylic resin is less than 10% by weight, the effect of improving scratch resistance and chemical resistance becomes insufficient, and the blending amount of the hydrogenated block copolymer is 20% by weight.
If it is below the range, the effect of improving flexibility and moldability becomes insufficient.

Examples of the copolymers having units compatible with the methacrylic resin and the hydrogenated block copolymer used in the present invention include olefin-methyl acrylate copolymers, polystyrene-polymethyl methacrylate graft polymers, and polyolefin-polymers. Examples thereof include polymethylmethacrylate graft polymers and styrene-methylmethacrylate copolymers. Examples of the styrene-based monomer used here include styrene, α-methylstyrene,
One or two or more kinds can be selected from vinyltoluene, p-tert-butylstyrene and the like, and the olefinic monomer can be one or more kinds from ethylene, propylene, ethyl acrylate, vinyl acetate and the like. You can choose. Furthermore, depending on the application, functional groups such as glycidyl methacrylate and maleic anhydride can be introduced.

The methacrylic resin and the hydrogenated block copolymer are compatible with 100 parts by weight of a composition prepared by mixing the hydrogenated block copolymer (1) and the methacrylic resin (2) at a predetermined ratio. The copolymer having a unit of 0.1 to
By mixing 20 parts by weight and kneading with a biaxial kneader or the like, a composition having good compatibility can be obtained. If the blending amount of the copolymer having units compatible with the methacrylic resin and the hydrogenated block copolymer is less than 0.1 parts by weight, the effect of improving the compatibility becomes insufficient, and the blending amount is 20 If it exceeds the parts by weight, various properties will deteriorate.

As described above, the copolymer having units compatible with the methacrylic resin and the hydrogenated block copolymer used in the present invention is remarkably compatible with the hydrogenated block copolymer and the methacrylic resin. And has the effect of significantly improving various properties such as heat resistance and mechanical properties. The reason for this is that the copolymer acts as a surfactant, It is considered that the compatibility between the block copolymer and the methacrylic resin was improved, and it became possible to have an incompatible microphase-separated structure.

If further flexibility is required, mineral oil called process oil or extender oil may be added as a softening agent for rubber. The composition of the present invention further contains other compounding agents, such as
Inorganic fillers such as talc, mica, calcium carbonate and wollastonite, or reinforcing agents such as glass fibers and carbon fibers, flame retardants, flame retardant aids, antistatic agents, stabilizers, pigments, release agents, etc. It can be blended. As the method for producing the composition of the present invention, all the general methods used for producing ordinary rubber compositions can be adopted. This is basically a mechanical melt-kneading method, and a single-screw extruder, a twin-screw extruder, a Banbury mixer, various kneaders and the like are used for these.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. << Examples 1 to 10 and Comparative Examples 1 to 3 >> After thoroughly dry-blending the compounds having the compounding ratios shown in the table, melt-kneading the mixture at a resin temperature of 220 to 230 ° C. using a biaxial kneader. It was extruded and pelletized. The pellets were kneaded at 230 ° C. using a Brabender and then compression molded to prepare test pieces. These test pieces were evaluated for hardness, tensile strength and elongation, and scratch resistance. The evaluation results are also shown in the table.

[0015]

[Table 1]

[0016]

[Table 2]

* 1: Hydrogenated block copolymer having a styrene content of 20 wt% * 2: Polymethylmethacrylate * 3: Polystyrene-polymethylmethacrylate graft copolymer * 4: Polyethylene-polymethylmethacrylate graft copolymer * 5: (Ethylene-ethyl acrylate copolymer) -Polymethyl methacrylate graft copolymer * 6: (Ethylene-vinyl acetate copolymer) -Polymethyl methacrylate graft copolymer * 7: Measured according to JIS K6301 (JIS
A) * 8: Measured according to JIS K6301. * 9: Evaluation was performed using a Gakushin-type friction tester. Conditions: Friction cloth (Kanakin No. 3 cloth) Load (500 g) Friction frequency (100 times) As the evaluation method, the gloss before and after the test was measured according to JIS Z8741, and the gloss remaining rate shown in the following formula was used for evaluation. Gloss residual rate (%) = {Gloss after test / Gloss before test}
× 100 In the table, ◯ indicates that the residual gloss ratio is 85% or more, and × indicates that the residual gloss ratio is less than 85%. * 10: (Styrene-glycidyl methacrylate copolymer) -Polymethyl methacrylate graft copolymer * 11: (Ethylene-glycidyl methacrylate copolymer) -Polymethyl methacrylate graft copolymer * 12: (Ethylene-ethyl acrylate-anhydrous Maleic acid copolymer) -polymethylmethacrylate graft copolymer * 13: Styrene-methylmethacrylate copolymer * 14: Ethylene-glycidylmethacrylate-methylacrylate copolymer

[0018]

As is apparent from the table, in the hydrogenated block copolymer composition of the present invention, it is necessary to add a copolymer having a compatible unit to the methacrylic resin and the hydrogenated block copolymer. As a result, the compatibility of the hydrogenated block copolymer and the methacrylic resin is remarkably improved, and it is a new and well-balanced material that has the advantages of both, is highly flexible, and is excellent in moldability and scratch resistance. ..

Claims (1)

[Claims] 1. A hydrogenated block copolymer comprising at least two terminal polymer blocks A mainly containing vinyl aromatic compounds and at least one intermediate polymer block B mainly containing conjugated diene compounds. The methacrylic resin and the hydrogenated block copolymer are compatible with 100 parts by weight of the resin composition consisting of 90 to 20% by weight of the hydrogenated block copolymer and 80 to 10% by weight of the methacrylic resin, respectively. 0.1 to 20 copolymers having the units shown
A hydrogenated block copolymer composition, which is added in parts by weight.