JP2978712B2 - Polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention can provide a molded article which is excellent in fluidity at the time of melting and has good moldability, and is excellent in flexibility, impact resistance, heat resistance and weather resistance. The present invention relates to a polymer composition and a molded article comprising the same, and in particular, the polymer composition of the present invention containing a polyolefin resin is suitable as a packing material such as a crown packing.

[0002]

2. Description of the Related Art A block copolymer comprising a diene polymer block and a vinyl aromatic monomer polymer block is excellent in impact resistance and flexibility, and has the same strength and strength as vulcanized rubber without vulcanization. Due to its elasticity, it is widely used as a material for improving the impact resistance of thermoplastic resins, and molded articles obtained from the thermoplastic resin composition containing the block copolymer or a hydrogenated product thereof are widely used. It is used in many applications as general goods, automobile parts, light electrical parts, various industrial goods, and the like.

[0003] For example, Japanese Patent Publication No. 55-18739 discloses that a hydrogenated product of styrene-isoprene-styrene block copolymer is mixed with polypropylene to improve low-temperature impact resistance. -56941
Japanese Patent Application Laid-Open Publication No. H11-146,086 describes that a similar block copolymer hydrogenated product is added to various engineering resins such as polyester and polyamide. In addition, International Patent Application No. 92/14790 describes that a styrene-isobutylene-styrene block copolymer is blended with various thermoplastic resins in order to improve the impact resistance and the like. However, in the case of these conventional techniques, although the impact resistance of a molded article obtained from a composition obtained by blending the block copolymer or a hydrogenated product thereof with a thermoplastic resin is improved, mechanical properties such as strength are reduced. Tends to decrease. In order to improve the impact resistance without lowering the mechanical properties such as strength by blending the hydrogenated block copolymer, if the molecular weight is 1 as the block copolymer.
It is necessary to use those having a molecular weight of not less than 100,000, and as a result, there is a problem that the fluidity of the resin composition is reduced and molding such as injection molding and extrusion molding becomes difficult.

Further, for example, Japanese Patent Publication No. 59-31541 discloses a method of blending a hydrogenated product of a styrene-butadiene-isoprene block copolymer with a polyolefin resin and a hydrocarbon-based softening agent to improve flexibility and processing. Although a composition having improved properties is described, molded articles obtained from this composition have low gas barrier properties and are not suitable for applications such as packing materials.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a molded article having excellent properties such as impact resistance, flexibility, heat resistance, weather resistance, and mechanical strength, and also having excellent gas and liquid barrier properties. Is to provide a polymer composition which can be produced with good moldability and has excellent fluidity at the time of heating and melting, and a molded article comprising such a polymer composition.

[0006]

As a result of repeated investigations by the present inventors, a triblock consisting of two vinyl aromatic monomer polymer blocks and one isobutylene polymer block was applied to a thermoplastic resin. Along with the polymer, a diblock copolymer consisting of a vinyl aromatic monomer polymer block and an isobutylene polymer block and a triblock copolymer consisting of two isobutylene polymer blocks and one vinyl aromatic monomer polymer block A polymer composition obtained by blending at least one of them is excellent in fluidity at the time of heating and melting, and can be formed extremely easily and smoothly, and the molded product obtained thereby is It has been found that it has excellent properties such as impact resistance, flexibility, heat resistance, weather resistance, and mechanical strength. As a result of further studies by the present inventors, even among such polymer compositions, polyolefin-based resins are used as thermoplastic resins, and more preferred are those obtained by blending a hydrocarbon-based softener. The united composition is not only excellent in the above-mentioned various properties, but also excellent in flexibility, and has a high barrier property against gas and liquid, and is used as various packing materials including crown packing. They have found that they can be used very effectively and have completed the present invention based on those findings.

That is, the present invention relates to (A) a thermoplastic resin; (B) a vinyl aromatic monomer polymer block-isobutylene polymer block-vinyl aromatic monomer polymer block having a number average molecular weight of 20,000 to 50.
000 triblock copolymer; and (C) a vinyl aromatic monomer polymer block-isobutylene polymer block having a number average molecular weight of 5,000 to 400,
000 diblock copolymer (C ₁ ) and a triblock copolymer (C) having a number average molecular weight of 5,000 to 400,000 composed of isobutylene polymer block-vinyl aromatic monomer polymer block-isobutylene polymer block. ₂ ) a polymer composition containing at least one of the following: {the thermoplastic resin (A)}: the triblock copolymer (B) and the diblock copolymer (C ₁ ) and / or
Or a total amount of the triblock copolymer (C ₂ ) is 95: 5 to 5:95 by weight, and a molded article obtained from the polymer composition. is there.

The present invention provides a polyolefin resin,
The triblock copolymer (B) consisting of the above-mentioned vinyl aromatic monomer polymer block-isobutylene polymer block-vinyl aromatic monomer polymer block and the diblock consisting of the above-mentioned vinyl aromatic monomer polymer block-isobutylene polymer block A polymer composition containing a block copolymer (C ₁ ), preferably further containing a hydrocarbon-based softener, and a packing material such as a crown packing obtained from the polymer composition are described in one preferred embodiment. Inclusive.

In the present invention, the thermoplastic resin used as the component (A) includes a homopolymer of an olefin monomer typified by polyethylene, polypropylene and the like, and propylene and α such as ethylene and / or 1-butene.
Polyolefin resins such as olefin copolymers obtained from two or more olefin monomers such as random copolymers and block copolymers with olefins; styrene resins such as polystyrene, high-impact polystyrene and ABS resins; polyethylene Polyester resins such as terephthalate and polybutylene terephthalate; polyamide resins such as nylon-6, nylon-66 and nylon-12; polycarbonate resins; polyphenylene ether resins and the like. These thermoplastic resins can be used alone. They may be used alone or in combination of two or more. Among them, it is particularly preferable to use one or both of polypropylene and a block copolymer of propylene and ethylene.

The components (B) and (C) in the polymer composition of the present invention are both block copolymers comprising a polymer block composed of a vinyl aromatic monomer and a polymer block composed of isobutylene. ,
The component (B) is a triblock copolymer consisting of a vinyl aromatic monomer polymer block-isobutylene polymer block-vinyl aromatic monomer polymer block,
The component (C) is a diblock copolymer (C ₁ ) composed of a vinyl aromatic monomer polymer block-isobutylene polymer block and a triblock composed of an isobutylene polymer block-vinyl aromatic monomer polymer block-isobutylene polymer block. It consists of at least one of the copolymers (C ₂ ).

In the present specification, hereinafter, the vinyl aromatic monomer polymer block will be referred to as "block a" and the isobutylene polymer block will be referred to as "block b", and block a-block b-block used as the component (B). the triblock copolymer consisting of a "a-b-a triblock copolymer (B)", a di-block copolymer consisting of block a- block b is used as the (C ₁₎ component "a-
b diblock copolymer (C ₁ ) ”and triblock copolymer composed of block b-block a-block b used as component (C ₂ ) are referred to as“ ba-ab triblock copolymer (C ₂₎ ) ".

In the diblock copolymer (C ₁ ) and the two kinds of triblock copolymers (B) and (C ₂ ), the vinyl aromatic monomers constituting the block a are styrene, α- Methylstyrene, β-methylstyrene, p-methylstyrene, t-butylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, indene, acenaphthylene and the like. Block a can be formed from one or more of these vinyl aromatic monomers. Among them, it is most preferred that the block a is formed from styrene.

In the polymer composition of the present invention, (B)
The aba triblock copolymer (B) is used as a component, and the aba triblock copolymer (B) is used.
Is a triblock copolymer in which a polymer block (block a) composed of a vinyl aromatic monomer and a polymer block (block b) composed of isobutylene are linearly bonded in the order of aba. The aba triblock copolymer (B) has a total number average molecular weight of 20,000.
５００500,000, 25,000-45
It is preferably in the range of 000. Although not limited, the number average molecular weight of the two blocks a is preferably in the range of 2,500 to 400,000, and the number average molecular weight of the block b is 10,000.
Preferably it is in the range of ~ 400,000. In the aba triblock copolymer (B), the ratio of the structural unit from the vinyl aromatic monomer and the structural unit from isobutylene is 5/95 to 80/20 by weight according to the present invention. It is preferable from the viewpoints of flexibility and impact resistance of a molded article obtained from the polymer composition.
/ 25 is more preferred.

Further, the polymer composition of the present invention comprises, as the component (C), an ab diblock copolymer (C ₁ ) and b-b
a-b triblock copolymer containing at least one of (C _2). The a-b diblock copolymer (C ₁ ) comprises a polymer block (block a) composed of a vinyl aromatic monomer and a polymer block (block b) composed of isobutylene, which are linearly ab or ba. And a bab triblock copolymer (C ₂ ) is composed of a polymer block (block b) composed of isobutylene and a polymer block composed of a vinyl aromatic monomer (block). a) is a triblock copolymer which is linearly bonded in the order of bab.

The ab diblock copolymer (C ₁ ) or bab triblock copolymer (C ₂ ) has a total number average molecular weight of 5,000 to 400,000, respectively.
0, and preferably in the range of 6,000 to 350,000. If the number average molecular weight of these block copolymers is less than 5,000, bleeding is likely to occur when blended with the thermoplastic resin (A).

Further, an ab diblock copolymer (C ₁ )
Alternatively, the ratio of the structural unit from the vinyl aromatic monomer and the structural unit from isobutylene in the baab triblock copolymer (C ₂ ) is preferably 5/95 to 80/20 by weight, and 90-75 / 25 is more preferred. If the weight ratio of the structural unit derived from the vinyl aromatic monomer to the structural unit derived from isobutylene is less than 5/95, the compatibility with the aba triblock copolymer (B) becomes poor, and bleeding is liable to occur. Become. 80/20
If it is larger than this, flexibility, especially at low temperatures, will be reduced.

The aba triblock copolymer (B) and the ab diblock copolymer (C ₁ ) used in the present invention
And a bab triblock copolymer (C ₂ ) have a functional group such as a halogen group such as chlorine, a carboxyl group, a hydroxyl group, an acid anhydride group or the like in a molecular chain or at a molecular terminal as necessary. May be. Further, an aba triblock copolymer, an ab diblock copolymer and a bab
The triblock copolymer may be copolymerized with another cationically polymerizable monomer within a range that does not impair the performance of the polymer composition of the present invention, and such another cationically polymerizable monomer may be used. Examples of the monomer include 1-butene, pentene, hexene, butadiene, isoprene, and methyl vinyl ether.

The aba triblock copolymer (B), the ab diblock copolymer (C ₁ ) and the bab triblock copolymer (C ₂ ) used in the present invention. Although the production method is not particularly limited, it can be produced, for example, by polymerizing a vinyl aromatic monomer and isobutylene in an inert solvent in order using a suitable polymerization initiator system so as to have respective block bonding sequences. Examples of the polymerization initiator system in that case include a mixture system of a Lewis acid and an organic compound that generates a cationic polymerization active species by the Lewis acid. Examples of the Lewis acid include titanium tetrachloride, tin tetrachloride, boron trichloride, and aluminum chloride. Examples of the organic compound include an organic compound having a functional group such as an alkoxy group, an acyloxy group, or a halogen group, such as bis (2-methoxy). -2-propyl) benzene, bis (2-
Acetoxy-2-propyl) benzene, bis (2-chloro-2-propyl) benzene and the like. Further, together with the Lewis acid and the organic compound, amides such as dimethylacetamide and dimethylformamide and esters such as ethyl acetate may be used as the third component, if necessary. Further, as the inert solvent for polymerization, hexane, cyclohexane, methylcyclohexane, methyl chloride, methylene chloride and the like can be used.

For example, the aba triblock copolymer (B) is prepared by using a Lewis acid and an organic compound having one functional group capable of generating a cationically polymerizable species as a polymerization initiator system to obtain a vinyl aromatic compound. After the group a is formed by polymerizing the aromatic monomer, isobutylene is added to the reaction system and polymerized to form the block b, and the vinyl aromatic monomer is again added to the reaction system and polymerized to form the block a . It can be manufactured by doing. Alternatively, as another method, a Lewis acid and a cationically polymerizable active species are formed.
Using an organic compound having a number of functional groups as a polymerization initiator system, first, isobutylene is polymerized to form a block b located at the center, and then a vinyl aromatic monomer is added into the reaction system to perform polymerization. Thus, it can be manufactured by forming blocks a at both ends of the blocks b. a
Case -b diblock copolymer _{(C 1)} and b-a-b triblock copolymer _{(C 2),} can be prepared analogously.

As another method, an ab diblock copolymer (C ₁ ) and / or a bab triblock copolymer may be used together with the aba triblock copolymer (B). When two or three kinds of organic compounds capable of producing (C ₂ ) are used in combination as a polymerization initiator system (for example, a monofunctional organic compound and a bifunctional organic compound are used in combination), ab
-A triblock copolymer (B) as well as a-b diblock copolymer (C ₁₎ and / or b-a-b triblock copolymer (C ₂₎ polymerizing a mixture block copolymer containing And may be used directly.

In the polymer composition of the present invention, {the thermoplastic resin (A)}: the triblock copolymer (B) and the diblock copolymer (C ₁ ) and / or the triblock copolymer (C ₂ ) is 95: 5 by weight
Each polymer is blended so that the ratio becomes 5:95. By setting such a mixing ratio, it is possible to obtain a polymer composition which is excellent in flexibility and impact resistance, and which has good fluidity when heated and melted and is excellent in moldability. On the other hand, when the proportion of the thermoplastic resin (A) is smaller than the above range (when the total amount of the block copolymer is larger than the above range), the mechanical strength of a molded article obtained from the polymer composition is reduced. On the other hand, when the proportion of the thermoplastic resin (A) is larger than the above range (when the total amount of the block copolymer is smaller than the above range), the flexibility and the resistance of the molded article obtained from the polymer composition are reduced. Impact properties are reduced. In view of the moldability of the polymer composition and the mechanical strength, flexibility and impact resistance of the molded article obtained from the polymer composition, {the thermoplastic resin (A)}:} the triblock copolymer (B ) And the diblock copolymer (C ₁ ) and / or the triblock copolymer (C ₂ ) are 90:10 to 10:90 by weight.
Is preferably blended so as to have a ratio of

Further, in the polymer composition of the present invention, Δa-
ba triblock copolymer (B)}: The ratio of {ab diblock copolymer (C ₁ ) and / or bab triblock copolymer (C ₂ )} is by weight. 99.5:
It is preferably in the range of 0.5 to 20:80, and 9
9.5: 0.5 to 30:70 is more preferable. a-b-
If the proportion of the a-triblock copolymer (B) is larger than the above range, the melt flowability of the polymer composition tends to be low and the molding processability tends to be inferior. When the proportion of the copolymer (B) is smaller than the above range, the melt flowability of the polymer composition is good, but the mechanical strength of a molded article obtained from the polymer composition tends to be lowered.

Further, the polymer composition of the present invention may contain, in addition to the component (A), the component (B), the component (C ₁ ) and / or the component (C ₂ ), the polymer composition of the present invention. If necessary, other polymers and additives may be contained as long as the performance of the above is not impaired. Examples of other polymers that can be blended include styrene-ethylene propylene-styrene block copolymer, styrene-ethylene propylene block copolymer, styrene-ethylene butylene-styrene block copolymer, and ethylene-propylene- non-conjugated diene copolymer. Examples thereof include a polymer (EPDM), polybutene, and polyisobutylene. Examples of additives include paraffinic oils for improving fluidity during molding,
Mineral oil softeners such as naphthenic oils; hydrocarbon softeners for improving flexibility; calcium carbonate, alumina, talc,
Examples include inorganic fillers such as carbon black, titanium oxide, silica, clay, barium sulfate, magnesium carbonate, mica, zeolite, and ferrite. Further, inorganic fibers such as glass fibers and carbon fibers, organic fibers and the like may be added for reinforcement. In addition, heat stabilizers, antioxidants, light stabilizers, pressure-sensitive adhesives, tackifiers, antistatic agents, foaming agents, and the like may be added.

In the above-mentioned polymer composition of the present invention, a polyolefin resin is used as the thermoplastic resin (A), and the a-ba triblock copolymer (B) and the a- The polymer composition obtained by blending the diblock copolymer (C ₁ ) with a hydrocarbon softening agent (hereinafter referred to as “hydrocarbon softening agent (D)”) preferably has moldability, flexibility, and durability. It has excellent barrier properties against gases and liquids, especially gas barrier properties, as well as various properties such as impact resistance, heat resistance and weather resistance, so it is suitable as a packing material that requires high barrier properties against gases and liquids. It can be effectively used as packing for various containers such as crown packing, packing materials for machines, instruments, devices and the like.

In the polymer composition and the packing material of the present invention, the hydrocarbon softener (D) is not always an essential component, but when used as a packing material, as described above, the hydrocarbon softening agent (D) has flexibility and gas barrier properties. From the viewpoint, it is preferable to contain a hydrocarbon softener (D). In this case, a polyolefin resin, an aba triblock copolymer (B) and an ab diblock copolymer (C ₁₎ )
Is preferably blended in a proportion of 1 to 200 parts by weight, more preferably 10 to 150 parts by weight, based on 100 parts by weight of the total. In general, if the content of the hydrocarbon softener (D) is less than 1 part by weight, flexibility and moldability tend to decrease, while if it is more than 200 parts by weight, it is required in the packing material. Mechanical performance tends to decrease.

Examples of the hydrocarbon softener (D) used in the present invention include hydrocarbon oils represented by process oils, and polyolefin softeners represented by polybutene oligomers and polyisobutene oligomers. These hydrocarbon softeners may be used alone or in combination of two or more.

The method for preparing the polymer composition of the present invention is not particularly limited, and examples thereof include a thermoplastic resin (A), an aba triblock copolymer (B), and an ab diblock copolymer ( The C ₁ ) and / or bab triblock copolymer (C ₂ ) may be mixed simultaneously with the other polymers and additives described above, if necessary, or may be mixed with the aba triblock. The copolymer (B) and the ab diblock copolymer (C ₁ ) and / or the bab triblock copolymer (C ₂ ) are preliminarily mixed to prepare a block copolymer mixture. In addition, this may be mixed with the thermoplastic resin (A) and, if necessary, the hydrocarbon softener (D) and other components, or directly by polymerization to form an aba triblock copolymer (B). ) and a-b diblock copolymer (C ₁₎ and / or b-a-b-tri Lock copolymer (C ₂₎ mixture to produce a block copolymer it and optionally the thermoplastic resin (A) may be admixed with other ingredients.
The mixing operation can be performed using a known mixing and / or kneading device such as an extruder, a kneader, a mixing roll, and a Banbury mixer. The temperature at the time of mixing or kneading may be appropriately adjusted depending on the melting temperature of the thermoplastic resin (A) to be used, and is usually 110 to 3
The heat treatment may be performed at a temperature of 00 ° C, preferably 180 to 280 ° C. The thus obtained polymer composition of the present invention is used as a molding material in an arbitrary form such as a pellet or a powder.

The polymer composition of the present invention can be molded by using a molding method or a molding apparatus generally used for thermoplastic polymers. For example, it can be molded by any molding method such as injection molding, extrusion molding, press molding, blow molding, calender molding, vacuum molding, etc., thereby forming a mold, pipe, sheet, film, fibrous material, etc. You can get a wide variety of products, including daily necessities, electrical / electronic components,
It can be used for various uses as a machine part, an automobile part, a food container, a packaging material, and the like. Above all, the polymer composition of the present invention is suitably used as various packing materials such as crown packing by utilizing its excellent flexibility, barrier properties such as gas barrier properties, and mechanical properties.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following Examples and Comparative Examples, parts represent parts by weight, and each physical property was determined by the following method.

(1) Number average molecular weight: measured by GPC. (2) mixing ratio of each block copolymer in the block copolymer mixture: a-b-a triblock copolymer (B) and a-b diblock copolymer (C ₁₎ and / or b- The mixing ratio of each block copolymer in the block copolymer mixture with the ab triblock copolymer (C ₂ ) was determined by a terminal group determination method using NMR. (3) Styrene unit content in block copolymer: Styrene unit content in each block copolymer is ¹ H-N
Determined by MR.

(4) Melt fluidity of polymer or polymer composition: The melt flow rate (MFR) of the polymer or polymer composition of the following examples or comparative examples was measured according to JIS K7210. And an index of melt fluidity. (5) Molded product flexibility: Initial Young's modulus is measured using the polymer or polymer composition of the following Examples or Comparative Examples according to JIS K7113, and JIS K72.
The hardness was measured in accordance with No. 15, and a comprehensive evaluation of flexibility was performed based on those values.

(6) Impact resistance of molded article: The polymer or the polymer composition of the following Examples or Comparative Examples was molded at a predetermined cylinder temperature and mold temperature by an injection molding machine and 20 cm in length. A sheet-shaped test piece having a width of 20 cm and a thickness of 2 mm was prepared, the test piece was fixed to a holder, and an eggplant-shaped weight having a weight of 3 kg was dropped from a predetermined height on the holder. The height at which 5 samples (50%) were broken was determined as the 50% breaking height, and was used as an index of impact resistance.

(7) Heat resistance of molded article: The same sheet-shaped test piece as in the impact resistance test was prepared, and this test piece was
After placing in an air oven at 50 ° C for 24 hours, take out and cool down to room temperature. Touch the surface of the test piece with a finger to check the stickiness. The case where there is no stickiness as before heating is good (◎), almost When there was no stickiness, it was evaluated as normal (○), when it was slightly sticky, it was slightly inferior (△), and when it was very sticky, it was evaluated as poor (x).

(8) Weather resistance of molded article: In Examples 1 to 8 and Comparative Examples 1 to 4, the same sheet-like test pieces as those in the above-described impact resistance test were subjected to JIS A
The test pieces were exposed in accordance with No. 1410, and the discolored and discolored state of the test pieces after the exposure was measured using a fade tester (“Ultraviolet Long Life Fade Meter” manufactured by Suga Corporation) to perform grading. In Examples 9 to 11 and Comparative Examples 5 to 6, the same sheet-shaped test pieces as those in the above-described impact resistance test were exposed for 100 hours by a weathering tester ("Jungle Tester PR2" manufactured by Tabai Espec Corp.). The appearance was visually observed to determine the presence or absence of coloring, and the retention rate of the tensile rupture strength after the weather resistance test to the tensile rupture strength of the test piece before the weather resistance test was obtained and evaluated.

(9) Tensile property test: JIS K7113
Using a No. 2 test piece, 100% elastic modulus, tensile strength at break and tensile elongation at break were measured, and a tensile property test was performed.

(10) Gas barrier property: The polymer or the polymer composition of the following example or comparative example was press-molded at a temperature higher than the melting temperature by 20 ° C. to have a thickness of 2
A film having a thickness of 00 μm was prepared, and using this film, a gas permeation measuring device (“GTR-1” manufactured by Yanagimoto Seisakusho) was used.
0 "), the oxygen barrier coefficient PO ₂ of the film at 35 ° C. was measured at an oxygen pressure of 2.5 kg / cm ² to evaluate the gas barrier properties.

<< Production Example 1 >> [Production of block copolymer mixture of aba triblock copolymer (B) and ab diblock copolymer (C ₁ )] (1) Stirrer Methylene chloride in a reactor equipped with
1 and 1200 ml of methylcyclohexane, 4.3 g of titanium tetrachloride (Lewis acid) as a polymerization initiator system, and a mixture of 1,4-bis (2-methoxy-2-propyl) benzene and 2-methoxy-2-propylbenzene 0 .
After adding 52 g, and charging 230 g of isobutylene at -70 ° C. and polymerizing for 4 hours, dimethylacetamide 0.13 was added.
g and 100 g of styrene were added thereto, and the mixture was further polymerized for 4 hours to obtain an aba triblock copolymer (B) and ab
A mixture of the diblock copolymer (C ₁ ) was produced. When the polymer composition in this mixture was examined by the method described above, [ab-a-triblock copolymer (B)] was obtained as follows:
[Ab diblock copolymer (C ₁ )] = 70:30 by weight. (2) When the number average molecular weight and the styrene unit content of each block copolymer in the block copolymer mixture were measured by the methods described above, the number average of the aba triblock copolymer (B) was determined. Molecular weight 120,000
0, the styrene unit content was 30% by weight;
b The number average molecular weight of the diblock copolymer (C ₁ ) is 60,
At 000, the styrene unit content was 30% by weight.

<< Production Examples 2 to 8 >> [Production of block copolymer mixture of aba triblock copolymer (B) and ab diblock copolymer (C ₁ )] An aba triblock copolymer (B) in which the polymer composition, the number average molecular weight of each block copolymer and the styrene unit content are as shown in Table 1 below in the same manner as in Production Example 1. And a mixture of ab diblock copolymer (C ₁ ).

<< Production Example 9 >> [aba triblock copolymer (B) and bab triblock copolymer (C
₂ ) Preparation of block copolymer mixture with)] In a reactor equipped with a stirrer purged with nitrogen, 800 ml of methylene chloride and 120 of methylcyclohexane were used as solvents.
0 ml, titanium tetrachloride (Lewis acid) as polymerization initiator system
4.3 g and 0.64 g of 1,4-bis (2-methoxy-propyl) benzene were added, 230 g of isobutylene was charged at −70 ° C., and polymerized for 4 hours. Then, 0.13 g of dimethylacetamide and 100 g of styrene were added. Further polymerization was carried out for 4 hours to produce an aba triblock copolymer (B). Similarly, in a reactor equipped with a stirrer purged with nitrogen, 800 ml of methylene chloride was used as a solvent.
And 1,200 ml of methylcyclohexane, 4.3 g of titanium tetrachloride (Lewis acid), 0.24 g of pyridine and 0.35 g of 1,4-bis (2-methoxy-propyl) benzene as polymerization initiator system, and styrene at -70 ° C. 2
After polymerizing 7 g for 4 hours, 63 g of isobutylene was added to
Polymerization was conducted for a time to produce a bab triblock copolymer (C ₂ ). The above prepared aba triblock copolymer (B) and bab triblock copolymer (C ₂ ) are mixed in a solution so as to have a weight ratio of 70/30, A block copolymer mixture was obtained.

<< Production Example 10 >> [Preparation of Block Copolymer (i) Consisting of Styrene Polymer Block and Isoprene Polymer Block] In a pressure-resistant reaction vessel equipped with a stirrer and a dropping funnel, 350 ml of cyclohexane and s-butyllithium were added. .64
g, the temperature was raised to 50 ° C., 177 g of styrene was continuously charged from the dropping funnel, and then 826 g of isoprene.
Was continuously charged, and then 177 g of styrene was continuously charged and polymerization was carried out for 2 hours to produce a triblock copolymer composed of a styrene block-isoprene block-styrene block. The obtained triblock copolymer was dissolved in cyclohexane to prepare a 10% solution, to which a palladium catalyst (hydrogenation catalyst) was added at a ratio of 0.5% by weight / polymer, and a hydrogen pressure was 20 kg / cm ^2. After the completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated and dried under reduced pressure to obtain a styrene block-hydrogenated isoprene block-styrene block water. Thus, a triblock copolymer (i) (hydrogenation rate: 97%) was obtained. The number average molecular weight of this triblock copolymer was 118,000, and the styrene unit content was 30%.

<< Production Example 11 >> [Production of Block Copolymer (ii) Consisting of Styrene Polymer Block and Isoprene Polymer Block] In the same manner as in Production Example 10, the number average molecular weight was 12
Styrene with a styrene unit content of 17% by weight,
A hydrogenated triblock copolymer (ii) consisting of a styrene block-hydrogenated isoprene block-styrene block (hydrogenation ratio 96%) was obtained.

[0042]

[Table 1]

Example 1 A block copolymer mixture of the aba triblock copolymer (B) and the ab diblock copolymer (C ₁ ) obtained in Production Example 1 above 30 parts of polypropylene (Mitsubishi Yuka “Noblen”
PY-230 ”), and the mixture was melt-kneaded at 200 ° C using a small twin-screw extruder and then extruded and cut to produce pellets of a polymer composition comprising polypropylene and a mixed block copolymer. The melt fluidity (MF
R) was measured by the method described above, and was as shown in Table 2 below. (2) Using the pellets obtained in (1) above, the above-described test piece was prepared, and its flexibility (initial Young's modulus, hardness), impact resistance, heat resistance, and weather resistance were measured or evaluated. And Table 2 below.

(3) The pellets obtained in the above (1) are mixed with a single screw extruder (full flight screw; L / D =
24; φ = 40 mm) and the cylinder temperature 22
5 ° C., extrusion rate 8 kg / Hr, extrusion rate 2.8 m / m
The sheet was extruded into a cooling water bath at a temperature of 60 ° C. under the conditions of “in” to produce a sheet. The obtained sheet was deep-drawn while being heated to 80 ° C. to obtain a cup-shaped molded product. This cup-shaped molded product was extremely excellent in impact resistance, and was not damaged even when dropped on a concrete floor from a height of 150 cm.

Comparative Example 1 The melt flowability was examined using only the same polypropylene as that used in Example 1 without adding the mixed block copolymer, and the above-mentioned test piece was prepared and its initial Young's strength was measured. Rate, hardness, impact resistance,
When the heat resistance and the weather resistance were measured or evaluated, they were as shown in Table 2 below. A cup-shaped molded product was produced in the same manner as in (1) of Example 1 using only this polypropylene, and dropped on a concrete floor from a height of 40 cm. I was

Examples 2 to 5 The same polypropylene as used in Example 1 is shown in Table 2 below for each of the block copolymer mixtures obtained in Production Examples 2 to 5 above. The polymer composition pellets were prepared in the same manner as in Example 1 by mixing at a ratio. Along with measuring the melt fluidity of the pellet, a test piece was prepared using the pellet to measure or evaluate the various physical properties described above.
The results are shown in Table 2 below.

<< Example 6 and Comparative Examples 2-3 >> Mixing ratio (weight ratio) of polypropylene and mixed block copolymer
As shown in Table 2 below, the weight was changed in the same manner as in Example 1 except that the ratio was changed to 10:90 (Example 6), 97: 3 (Comparative Example 2) and 3:97 (Comparative Example 3). The combined composition pellets were prepared and the melt fluidity of the pellets was measured, and a test piece was prepared using the pellets to measure or evaluate the various physical properties described above. The results were as shown in Table 2 below. .

<< Examples 7 and 8 >> Polymer composition pellets were prepared in the same manner as in Example 1 except that the block copolymer mixtures obtained in Production Examples 6 and 9 were used. The melt flowability of the pellets was measured, and a test piece was prepared using the pellets. The various physical properties described above were measured or evaluated. The results are as shown in Table 2 below.

Comparative Example 4 Except that the triblock copolymer (i) consisting of a styrene block, a hydrogenated isoprene block and a styrene block obtained in Production Example 10 was used instead of the block copolymer mixture. Is Example 1
A pellet was prepared in the same manner as above, and the melt fluidity of the pellet was measured, and a test piece was prepared using the pellet to measure or evaluate the above-described various properties.
The results are shown in Table 2 below.

[0050]

[Table 2]

From the results shown in Table 2 above, the polymer compositions of Example 1 and Examples 3 to 8 were excellent in melt fluidity (molding processability), and were obtained from these polymer compositions. It is understood that the molded product is excellent in flexibility, impact resistance, heat resistance and weather resistance. On the other hand, Comparative Example 1 using only polypropylene and the total content of the aba triblock copolymer (B) and the ab diblock copolymer (C ₁ ) were out of the range of the present invention. When a small amount of the polymer composition of Comparative Example 2 was used, the flexibility and impact resistance of the molded article were inferior, and the aba triblock copolymer (B) and ab diblock copolymer The molded article obtained from the polymer composition of Comparative Example 3 in which the total content of the union (C ₁ ) is out of the range of the present invention is inferior in tensile strength, and the triblock copolymer (B) and the block Copolymer (C)
And a molded product obtained from the polymer composition of Comparative Example 4 comprising a triblock copolymer (i) composed of a styrene block-hydrogenated isoprene block-styrene block and polypropylene, and having heat resistance and It turns out that it is inferior to weather resistance. Further, from the results of Example 2, in order to enhance the flowability of the polymer composition and improve the molding processability, the block copolymer (C) in the polymer composition of the present invention was used as a triblock. It can be seen that it is desirable to contain more than 3% by weight based on the total weight of the copolymer (B) and the block copolymer (C).

<< Examples 9 to 10 >> 100 parts of a polyolefin resin ("Noblen MA-3" manufactured by Mitsubishi Yuka Co., Ltd.)
200 parts of the block copolymer mixture obtained in Production Example 7 or Production Example 8 or 100 parts of a hydrocarbon-based softener [“Diana Process PW-90” (paraffin oil) manufactured by Idemitsu Kosan Co., Ltd.] is mixed. Twin screw extruder (screw rotation speed 200 rpm) at 200 ° C. under nitrogen atmosphere
The mixture was melt-mixed using m), extruded and cut to produce pellets of the polymer composition. Various test pieces were prepared by injection molding using the pellets, and their tensile properties (100
% Elastic modulus, tensile rupture strength and tensile rupture elongation), weather resistance (change in appearance and strength retention) and gas barrier property (oxygen permeability) were measured or evaluated by the above-mentioned methods. The results shown were obtained.

Example 11 Pellets were produced and various test pieces were prepared in the same manner as in Example 9 except that no hydrocarbon softener was added, and the physical properties were evaluated in the same manner. The results are shown in Table 3 below.

Comparative Example 5 Various test pieces were prepared in the same manner as in Example 9 using only the same polyolefin resin as used in Example 9, and the physical properties of the test pieces were evaluated in the same manner. Was done. The results are shown in Table 3 below.

Comparative Example 6 Instead of the block copolymer mixture, the triblock copolymer (ii) consisting of the styrene block-hydrogenated isoprene block-styrene block obtained in Production Example 11 was used. Production of pellets and production of various test pieces were performed in the same manner as in Example 9, and the physical properties were evaluated in the same manner. The results are shown in Table 3 below.

[0056]

[Table 3]

From the results in Table 3 above, the polyolefin resin, aba triblock copolymer (B) and a
-B diblock copolymer _{(C 1)} containing Example 9
The polymer composition of the present invention is excellent in mechanical properties and weather resistance, and is also excellent in flexibility and gas barrier properties, and is suitable as a packing material. Among them, a hydrocarbon softener (D) Examples 9 and 1 containing
It can be seen that the polymer composition of No. 0 is more excellent in flexibility and gas barrier properties, and is more suitable as a packing material. On the other hand, in the case of Comparative Example 5 using only the polyolefin-based resin, although the weather resistance and the gas barrier properties were excellent, the flexibility was remarkably insufficient, and it was not suitable as a packing material. -a triblock copolymer (B) and a-b diblock copolymer in place of (C ₁₎ and a mixture of styrenic block - containing triblock copolymer consisting of styrene block - hydrogenated isoprene block Although the polymer composition of Comparative Example 6 was excellent in flexibility, it was found that the gas barrier property was extremely low and inferior, the weather resistance was low , and the physical properties required for the packing material were not provided.

Example 12 Pellets were produced using the same polymer composition as in Example 9, and the pellets were fed under a nitrogen atmosphere at 200 ° C. to a twin-screw extruder equipped with a T-die. The sheet was extruded at a rotation speed of 200 rpm to produce a sheet having a thickness of 100 μm. The flexibility (value of 100% elastic modulus, tensile breaking strength and tensile breaking elongation) and gas barrier property (oxygen permeability coefficient PO ₂ ) of this sheet
Was about the same as Example 9 shown in Table 3 above, and had good flexibility and extremely high gas barrier properties. This sheet was used as a crown packing for a bottle for orange juice to produce a crown, and the bottle filled with orange juice was covered with the crown in a conventional manner and sealed. After storing the orange juice at room temperature for 3 months, opening the bottle stopper (crown) and tasting the contents, the flavor and texture were not changed at all, and were kept well. Had packing properties.

[0059]

EFFECTS OF THE INVENTION The polymer composition of the present invention is excellent in fluidity at the time of melting and has good moldability, so that it can be extruded.
Molds, pipes, sheets, films, fibrous materials, and various other molded products and products by injection molding, blow molding, press molding, vacuum molding, or other general-purpose melt molding or heat processing methods. Can be manufactured very easily and smoothly. The molded article obtained from the polymer composition of the present invention is excellent in various properties such as flexibility, impact resistance, heat resistance, weather resistance and mechanical strength, and can be used favorably without breakage.

The polymer composition of the present invention obtained by using a polyolefin resin as the thermoplastic resin (A),
Flexibility, weather resistance and gas and liquid barrier properties,
In particular, it has excellent gas barrier properties and can be effectively used as various packing materials such as crown packings. In particular, polyolefin resins, triblock copolymers (B) and diblock copolymers (C ₁ ) In addition, the polymer composition of the present invention further containing a hydrocarbon softener (D) has further excellent flexibility and gas barrier properties, and the packing material of the present invention such as a crown packing obtained therefrom is extremely poor. It has good sealing properties and workability at the time of sealing, and can store contents put in containers and the like stably and with high quality for a long period of time.

────────────────────────────────────────────────── ─── of the front page continued (72) inventor Maeda, Mizuho Ibaraki Prefecture Kashima-gun, Kamisu Higashiwada 36 address stock company within the Kuraray (58) investigated the field (Int.Cl. ^6, DB name) C08L 53/02 C08L 23 / 00-23/36

Claims (6)

(57) [Claims] 1. A thermoplastic resin having a number average molecular weight of 20,000 to 500,000 comprising (A) a thermoplastic resin; (B) a vinyl aromatic monomer polymer block-isobutylene polymer block-vinyl aromatic monomer polymer block. block copolymer; and (C) a vinyl aromatic monomer polymer block - isobutylene polymer number average molecular weight consisting block diblock copolymer 5,000~400,000 (C ₁₎ and isobutylene polymer block - The number average molecular weight of the vinyl aromatic monomer polymer block-isobutylene polymer block is from 5,000 to 400,
Triblock copolymer 000 a polymer composition containing at least one of (C _2), {the thermoplastic resin (A)}: {triblock copolymer (B) diblock copolymerization The total amount of the combined (C ₁ ) and / or triblock copolymer (C ₂ ) is 95: 5 to 5:95 by weight.
A polymer composition comprising: 2. The polymer composition according to claim 1, wherein the thermoplastic resin (A) is a polyolefin resin. 3. A polyolefin resin and a triblock.
Contains polymer (B) and diblock copolymer (C ₁ )
And, further hydrocarbon softening agent, 200 weight for the total amount 100 parts by weight of the polyolefin resin, triblock copolymer (B) and diblock copolymers (C ₁₎
The polymer composition according to claim 2, which is contained in a proportion of not more than 3 parts by weight. 4. A molded article obtained from the polymer composition according to claim 1. 5. A packing material obtained from the polymer composition according to claim 2. 6. The packing material according to claim 5, which is a crown packing.