JPS6234782B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composition comprising (a) a polyolefin resin, (b) a polystyrene resin, and (c) a hydrogenated block copolymer. This relates to a thermoplastic resin composition with excellent impact resistance and rigidity, which has the structure of be. Conventionally, polyolefin resins such as polyethylene and polypropylene have been used for many purposes such as films, sheets, injection molded products, and blow molded products because they are inexpensive. However, the above polyolefin resin
Although they have many excellent properties, they lack rigidity and impact resistance, and opportunities to further expand the applications of these resins have been missed. In order to improve the rigidity of the polyolefin resin, attempts have been made to mix polystyrene resin with it. However, polyolefin resins and polystyrene resins have poor compatibility, so even if an apparently homogeneous mixture is obtained by mechanically melt-mixing the two, the mixture is generally brittle and compared to the original polyolefin resin. As a result, the impact resistance is significantly reduced, and in the end, only products of extremely low practical value are obtained. In order to improve the compatibility of the mixture of the two, a specific styrene-conjugated diene block copolymer, its hydrogenated block copolymer, or ethylene-vinyl acetate copolymer is added to the polyolefin resin and polystyrene resin. A composition comprising: For example, in JP-A No. 49-28637, polyethylene and polystyrene resins are
Furthermore, a composition obtained by adding a vinyl aromatic compound-conjugated diene block copolymer represented by the general formula (A-B)n, B-(A-B)n or A-(B-A)n is disclosed. has been done. Also, Tokukai Akira
54-53159, A-B-A, A-(B-A
A composition is disclosed in which a linear or branched hydrogenated block polymer such as -B)n-A or (A) _4B is premixed with an olefin resin, and this is mixed with a polystyrene resin. However, although the composition described in JP-A No. 49-28637 tends to improve impact resistance, it is not sufficient, and it also has drawbacks such as reduced weather resistance. Practically unfavorable. Further, the composition described in JP-A-54-53159 is not preferred in practice because it requires premixing, which makes the operation complicated, and it has poor oil resistance and impact resistance. In view of the current situation, the present inventors conducted various studies in order to improve the impact resistance and rigidity of polyolefin resins with simple operations, and as a result, they found that polyolefin resins, polystyrene resins, and specific By adding hydrogenated block copolymer,
It was discovered that a thermoplastic resin composition with excellent oil resistance, impact resistance, and rigidity can be obtained, leading to the present invention. That is, the thermoplastic resin composition according to the present invention comprises (a) a polyolefin resin, (b) a polystyrene resin, (c) at least one vinyl-substituted aromatic compound polymer block A and a conjugated diene polymer block. At least 70 of the double bonds in the block copolymer are hydrogenated by hydrogenating a block copolymer having at least one B and containing 15 to 85% by weight of a bonded vinyl-substituted aromatic compound. %, and the composition ratio of component (a) and component (b) is 50 to 95:
50 to 5 (weight ratio), and the content of component (c) is 3 parts by weight per 100 parts by weight of components (a) and (b).
~50 parts by weight. The hydrogenated block copolymer (c) used in the present invention comprises at least one vinyl-substituted aromatic compound polymer block A and a conjugated diene polymer block B.
obtained by hydrogenating a block copolymer having at least one bonded vinyl-substituted aromatic compound content of 15 to 85% by weight, wherein at least one of the double bonds in the block copolymer is It is a hydrogenated block copolymer that is 70% saturated. Vinyl-substituted aromatic compound polymer block A is
It is a polymer consisting of styrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, or a mixture thereof. Conjugated diene polymer block B includes 1,3-butadiene, isoprene, 1,3-pentadiene,
2,3-dimethyl-1,3-butadiene, 3-butyl-1,3-octadiene, 4-ethyl-1,
A polymer consisting of 3-hexadiene or a mixture thereof, or a mixture of the above conjugated diene and a vinyl-substituted aromatic compound. and preferably a 1,4-structure content of 75% by weight
The content of the above conjugated diene polymer or vinyl-substituted aromatic compound is 25% by weight or less. 1,
A conjugated diene-vinyl substituted aromatic compound copolymer having a 4-structure content of 75% by weight or more. Most preferably, from the balance between impact resistance and rigidity,
Polybutadiene with a 1,4-structure content of 80% by weight or more. The bonded vinyl-substituted aromatic compound content of the block copolymer consisting of block A and block B is
15-85% by weight. If it deviates from the above range, the effect of improving the impact resistance of the composition will decrease, which is not preferred in practice. The block structure of the block copolymer is not particularly limited as long as it has at least one vinyl-substituted aromatic compound polymer block A and at least one conjugated diene polymer block B. A polymer lacking block A or B becomes a polyolefin resin or a polystyrene resin, and the impact resistance of the composition of the present invention is significantly reduced. A preferred block structure is the A-B type 2 structure from the viewpoint of the balance between impact resistance and rigidity, but a particularly preferred block structure is the A and B type structure.
It is a so-called tapering type A-B block in which the vinyl-substituted aromatic compound content decreases along the main chain between the two. The molecular weight of the block copolymer is not particularly limited, but is generally 5,000 to 1,000,000.
It is. Furthermore, in the block copolymer of the present invention, 70% or more of the double bonds of component B are saturated;
If it is less than 70%, the impact resistance of the resin composition decreases, which is not preferred in practice. In the resin composition of the present invention, the content of (c) hydrogenated block copolymer is equal to that of component (a) and component (b).
The amount is 3 to 50 parts by weight per 100 parts by weight, but if it is less than 3% by weight, the impact resistance of the resin composition will decrease, and if it exceeds 50% by weight, the effect of adding the polyolefin resin will be lost, making it difficult to put into practical use. Not good. (c) The method for producing the hydrogenated block copolymer is not particularly limited, and any known method may be employed. For example, it is described in Japanese Patent Publication No. 36-19286. A block copolymer consisting of a vinyl-substituted aromatic compound and a conjugated diene was produced using living anionic polymerization technology using an organolithium catalyst, and the nickel compound described in Japanese Patent Publication No. 1987-8704 was produced. It can be obtained by hydrogenating the above block copolymer using an organoaluminium compound as a catalyst. The composition ratio of (a) polyolefin resin and (b) polystyrene resin in the resin composition of the present invention is determined from the viewpoint of the balance between oil resistance, impact resistance, and rigidity.
50-95:50-5 (weight ratio) is preferred. Regarding the composition ratio of component (a) and component (b), if the amount of component (a) is less than 50:50, the oil resistance and impact resistance of the composition will decrease, and if it exceeds 95:5, the composition will deteriorate. The stiffness of the object decreases. (a) The polyolefin resin may be any resin obtained by polymerizing α-olefin,
For example, polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymers or carboxylated modified resins thereof, or mixtures thereof, particularly preferably polyethylene and polypropylene. (b) Examples of the polystyrene resin include polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer, and acrylonitrile-styrene copolymer.
It is a resin made of vinyl-substituted aromatic compounds such as butadiene-styrene copolymer, methyl methacrylate-styrene copolymer, and conjugated diene-styrene block copolymer, but especially polystyrene,
Rubber modified polystyrene and conjugated diene-styrene block copolymers are preferred. The resin composition of the present invention can contain any filler if necessary. The type of filler is not particularly limited as long as it is commonly used in plastic formulations, but typical examples include flame retardants, glass fibers, glass beads, organic fibers, titanium white, carbon black, Pigments such as iron oxide, silica,
Examples include inorganic reinforcing agents such as charcoal and talc, organic reinforcing agents such as coumaron indene resin, metal powder, wood flour, other fillers, and mixtures thereof. These fillers can be appropriately selected depending on the use of the resin composition of the present invention. Furthermore, if necessary, appropriate amounts of other additives conventionally used in plastic formulations, such as antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, lubricants, and plasticizers, are used. You can also. In the present invention, (a) polyolefin resin, (b)
A thermoplastic resin composition containing a polystyrene resin and (c) a hydrogenated block copolymer can be produced by any conventional compounding method. Such methods include, for example, mechanical mixing using a roll, banbury, extruder, etc., or dissolving or dispersing the compound in a solution, and then evaporating the solvent to obtain the resin composition. be able to. The resin composition of the present invention thus obtained can be easily molded into molded articles of various shapes by any conventionally known molding method, such as injection molding or extrusion molding. The thermoplastic resin composition of the present invention having the above structure has (a) a polyolefin resin, (b) a polystyrene resin, and (c) a hydrogenated block copolymer uniformly dispersed therein. It has superior rigidity and impact resistance compared to resins, and has an excellent balance of oil resistance, rigidity, and impact resistance compared to known compositions consisting of polyolefin resins, polystyrene resins, and third components. Are better. Therefore, the thermoplastic resin composition of the present invention is
It can be made into a wide variety of practically useful products such as films, foams, sheets, injection molded products, and compression molded products, and is of extremely great industrial significance. EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 4 and Comparative Examples 1 to 5 An autoclave with an internal volume of 1 equipped with a stirrer and a jacket was washed, dried, and purged with nitrogen, and while keeping the autoclave at 70°C, 50.0 g of butadiene that had been purified and dried in advance and cyclohexane were added. Supplied 250g. Next, 0.100 g of a hexane solution of butyllithium was supplied in terms of butyllithium to initiate the polymerization reaction. One hour after adding the catalyst, 50.0 g of pre-purified styrene and 250 g of cyclohexane were added.
was added, the temperature was kept at 50°C, and polymerization was carried out for 1 hour. The obtained copolymer solution was diluted to 5% by weight with cyclohexane, and 0.235 g of a hexane solution of nickel octenoate in terms of nickel was added to this copolymer solution as a catalyst, and a hexane solution of triethylaluminum was added as a catalyst. A calculated amount of 1.37g was added, and the reaction was carried out at 50°C for about 6 hours under hydrogen pressure. The obtained hydrogenated copolymer solution was washed three times with an aqueous chlorine solution to remove catalyst residue. Butylated hydroxytoluene (BHT) was added to the hydrogenated copolymer solution washed with water as a stabilizer.
After adding , the hydrogenated copolymer was precipitated using excess methanol, and the precipitate was dried under reduced pressure.
The MI(G) of the obtained hydrogenated copolymer was 9.0, the bound styrene content was 50%, and the butadiene component was 92%.
was hydrogenated (referred to as Example 1 sample). A type 2 block copolymer with an MI(G) of 9.5, a bound styrene content of 80%, and 94% of the butadiene component was hydrogenated was obtained by the same manufacturing method as the Example 1 sample (Example 2 sample). ). Similarly, MI(G) 1.0, bound styrene content 20%
A type 2 block copolymer in which 92% of the butadiene component was hydrogenated was obtained (referred to as a sample of Example 3). Next, the autoclave No. 1 used for producing the sample of Example 1 was maintained at 50° C., and 15.0 g of styrene and 75.0 g of cyclohexane were supplied. Next, 0.100 g of a hexane solution of butyllithium was supplied in terms of butyllithium to start the polymerization reaction. One hour after adding the catalyst, 70.0 g of butadiene and 350 g of cyclohexane were added and polymerized at 50°C, and after another hour, 15.0 g of styrene and cyclohexane were added.
75.0g was added and polymerization was carried out for 1 hour. The obtained copolymer was hydrogenated in the same manner as in Example 1, and MI
(G) 2, a copolymer in which 95% of the butadiene component was hydrogenated was obtained (referred to as Example 4 sample). Next, as a comparative example, MI(G) with a bound styrene content of 10% was produced using the same polymerization method as the Example 1 sample.
0.1, a type 2 block copolymer in which 92% of the butadiene component was hydrogenated (comparative example 1 sample), a bound styrene content of 90%, MI(G) 12.5
A type 2 block copolymer (referred to as comparative example 2 sample) in which 94% of the butadiene component was hydrogenated was obtained. In addition, a type 3 block copolymer having a bound styrene content of 30% and an MI(G) of 9.0 was obtained using the same manufacturing method as the sample of Comparative Example 1, except that the hydrogenation reaction was not carried out (Sample of Comparative Example 3). ). 30 parts by weight each of the seven types of samples obtained in this way or a commercially available ethylene-vinyl acetate copolymer (manufactured by Mitsui Polychemical Co., Ltd., Evaflex 460) were added to 50 parts by weight of commercially available polystyrene (manufactured by Asahi Dow, Styron 683).
parts by weight and 50 parts by weight of high-density polyethylene (Santech 241, manufactured by Asahi Kasei Industries), and melt-mixed for about 10 minutes at a mixing temperature of 190 to 200°C using a Banbury mixer. After taking out the blended composition from the mixer, it was passed through a crusher and an extruder to form pellets. The Izot impact strength and hardness (Shor-D) of compression-molded pieces of the obtained composition were measured. The results are shown in Table 1. The resin composition containing the hydrogenated block copolymer of the present invention includes a hydrogenated block copolymer having a bound styrene content outside the range of the present invention, a non-hydrogenated block copolymer, and an ethylene-vinyl acetate copolymer. It exhibited much higher Izot impact strength than resin compositions containing polymers.

[Table] Example 5 and Comparative Example 6 The autoclave 1 used in Example 1 was heated to 70
℃, supplied 20 g of styrene, 13.3 g of butadiene and 133.2 g of cyclohexane, added 0.100 g of a hexane solution of butyl lithium in terms of butyl lithium, polymerized for 1 hour, then added 20 g of styrene, 46.7 g of butadiene and 266.8 g of cyclohexane. and continued polymerization for 1 hour. As a result, the bound styrene content is 40%, the blocked styrene content is 32%, and MI(G)
A decreasing block copolymer of 10.4 was obtained. Next, the reaction time was 1.5 as in Example 1 sample.
Type 4 block copolymers were obtained in which the butadiene component was hydrogenated by 60% and 80% by varying the time and 2.5 hours (samples of Comparative Example 6 and Example 5). 10 parts by weight of the hydrogenated block copolymer thus obtained, 70 parts by weight of polypropylene (Chitsuku PP 1011, manufactured by Chitsuso Corporation) and 30 parts by weight of polystyrene (Styron 683, manufactured by Asahi Dow Corporation),
Melt mixing was carried out for about 10 minutes at a kneading temperature of 210 to 220°C using a Banbury mixer. After the blended composition was taken out of the mixer, it was passed through a crusher and an extruder to form pellets. A film with a thickness of about 300 μm was extruded from a 40 mm extruder at a processing temperature of 250° C., cooled with a cooling roll (temperature 105° C.), and then wound. Table 2 shows the results of measuring the physical properties of the obtained film. Example 5, in which the hydrogenation rate of the hydrogenated block copolymer falls within the range of the present invention, has significantly higher dart impact strength than Comparative Example 6, in which the hydrogenation rate does not fall within the range of the present invention. It was excellent.

[Table] Examples 6, 7 and Comparative Example 7 The autoclave No. 1 used in the production of the Example 1 sample was kept at 70°C, 50 g of styrene, 50 g of butadiene, and 500 g of cyclohexane were supplied, and a hexane solution of butyl lithium was mixed with butyl lithium. 0.100g was added and polymerized for 1 hour. the result,
50% bound styrene content, 40% blocked styrene content
A type 2 block copolymer with a decreasing rate of % was obtained. This block copolymer was subjected to a hydrogenation reaction in the same manner as in Example 1, and 95% of the butadiene component was hydrogenated.
A block copolymer of MI(G) 11.3 was obtained (Example 6
sample). 30 parts by weight of the hydrogenated block copolymer thus obtained was mixed with a high-density polyethylene (Santech 241 manufactured by Asahi Kasei Corporation) and polystyrene (Stylon 683 manufactured by Asahi Dow) in a weight ratio of 80/20 (Example 1). 6), 50/50 (Example 7), 20/80 (Comparative Example 7)
It was added to 100 parts by weight of the resin mixture, which was molded in the same manner as in Example 1, and the hardness, Izot impact strength and oil resistance were measured. The results are shown in Table 3. As a result, it can be seen that resin compositions in which the polyolefin component content is less than that of the resin composition of the present invention have lower oil resistance and impact resistance, and are not preferred in practice.

[Table] After that, the adhesiveness of the surface was examined.
Examples 8 to 11 and Comparative Example 8 The autoclave 1 used in the production of the Example 1 sample was kept at 50°C, 50 g of styrene and 250 g of cyclohexane were supplied, and 0.100 g of a hexane solution of butyl lithium was added in terms of butyl lithium. Then, 12.0 g of tetrahydrofuran (THF), 50 g of butadiene, and 250 g of cyclohexane were added, and the mixture was polymerized for 1 hour. As a result, the bound styrene content is 50%, the vinyl content is 50% A-
A type B block copolymer was obtained. This block copolymer was hydrogenated in the same manner as in Example 1 to obtain a block copolymer with an MI(G) of 9.5 in which 97% of the butadiene component was hydrogenated (referred to as a sample of Example 8). Furthermore, in the same manner, the bound styrene content of the A-B-A type was 50%, the vinyl content before hydrogenation was 50%, the MI
A hydrogenated block copolymer in which 97% of (G)12.3 and butadiene components were hydrogenated was obtained (Example 9
sample). The hydrogenated block copolymer thus obtained and 10 parts by weight of the hydrogenated block copolymer used in Examples 1 and 6 were added to impact-resistant rubber-reinforced polystyrene (manufactured by Asahi Dow, Stylon).
475S) and 50 parts by weight of polyethylene (Santech 241, manufactured by Asahi Kasei Industries, Ltd.), molded in the same manner as in Example 1, and measured for physical properties. The results are shown in Table 4. Each of the examples had an excellent balance between Izot impact strength and hardness. Resin compositions containing type 2 hydrogenated block copolymers with particularly low vinyl content before hydrogenation (Examples 10 and 11)
was excellent.

[Table] Examples 12 and 13 have a polystyrene-polybutadiene structure,
An A-B type block copolymer with a bound styrene content of 30% by weight and a 1,2 bond content of 40% was hydrogenated in the same manner as in Example 1 to obtain MI(G)10.2 in which 97% of the butadiene component was hydrogenated. A block copolymer of (Example) was obtained.
12 samples). Furthermore, it has a polybutadiene-polystyrene-polybutadiene-polystyrene structure, with a bound styrene content of 30% by weight and a 1,2 bond content of 36%.
Example 1
Hydrogenation was carried out in the same manner as above to obtain a block copolymer with MI(G) 1.5 in which 97% of the butadiene component was hydrogenated (referred to as Example 13 sample). 30 parts by weight of the hydrogenated block copolymer thus obtained was blended with 50 parts by weight of commercially available polystyrene (Styron 683, manufactured by Asahi Kasei) and 50 parts by weight of high-density polyethylene (Santec 241, manufactured by Asahi Kasei), and the Melt and knead in the same manner as Examples 1 to 4,
Test pieces were obtained and evaluated in the same manner as in Examples 1-4. The results are listed in Table 5. The resin composition containing the hydrogenated block copolymer of the present invention has a good effect of improving the Izot impact strength.

【table】

Claims (1)

[Scope of Claims] 1 (a) polyolefin resin, (b) polystyrene resin, (c) at least one vinyl-substituted aromatic compound polymer block A and at least one conjugated diene polymer block B By hydrogenating a block copolymer having a bonded vinyl-substituted aromatic compound content of 15 to 85% by weight, at least 70% of the double bonds in the block copolymer are saturated. hydrogenated block copolymer with a composition ratio of component (a) and component (b) of 50 to 50.
95:50 to 5 (weight ratio), and the content of component (c) is 3 to 50 parts by weight per 100 parts by weight of components (a) and (b). Resin composition. 2. A block copolymer having a vinyl-substituted aromatic compound block A and a conjugated diene polymer block B is an A-B type block copolymer, and 75% by weight or more of the conjugated diene in the block copolymer is The thermoplastic resin composition according to claim 1, which has a 1,4 structure. 3 (a) The polyolefin resin is polyethylene, polypropylene, ethylene-propylene copolymer,
The thermoplastic resin composition according to claim 1 or 2, which is polymethylpentene, a carboxyl-modified resin thereof, or a mixture thereof. 4 (b) The polystyrene resin is selected from polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-styrene copolymer, and conjugated diene-styrene block copolymer. Claim 1, which is one type of
The thermoplastic resin composition according to any one of Items 1 to 3. 5. A patent claim in which the vinyl-substituted aromatic compound in the vinyl-substituted aromatic compound polymer block A is styrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, or a mixture thereof. The thermoplastic resin composition according to any one of items 1 to 4. 6 Conjugated diene in conjugated diene polymer block B is 1,3-butadiene, isoprene, 1,3-
Pentadiene, 2,3-dimethyl-1,3-butadiene, 3-methyl-1,3-octadiene, 4
The thermoplastic resin composition according to any one of claims 1 to 5, which is -ethyl-1,3-hexadiene or a mixture thereof.