JPH0637539B2 - Block copolymer mixture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a block composed of a vinyl aromatic hydrocarbon and a conjugated diene, which have excellent transparency, impact resistance, tear strength, and good blow moldability. It relates to polymer mixtures.

[Conventional technology]

A block copolymer composed of a conjugated diene and a vinyl aromatic hydrocarbon has excellent transparency when the content of the vinyl aromatic hydrocarbon is relatively high, and a thermoplastic resin having a better impact resistance than polystyrene can be obtained. In recent years, its usage has been increasing mainly in fields such as food packaging containers, daily sundries, toys, and light electric parts.

Various production methods of such block copolymers are known, and for example, JP-B-36-19286 and JP-B-43-17979.
There are block copolymers described in JP-B No. 48-2423, JP-B No. 57-49567, and JP-B No. 58-11446.

[Problems to be solved by the invention]

However, the block copolymers disclosed in these methods are insufficient in impact resistance and tear strength, and improvement thereof is desired. Further, the block copolymer is inferior in blow moldability and causes problems such as drawdown and poor gloss of a molded product.

As a method for improving the impact resistance of a block copolymer, there is known a method of combining different block copolymers as disclosed in JP-A-57-28150 and JP-B-55-5544. However, it is still insufficient in terms of blow moldability, and a further improved method is desired.

[Means and Actions for Solving Problems]

The present inventors have set the molecular weight of the block copolymer constituting the main component in a specific range, and by combining a specific amount of a high molecular weight block copolymer, the above problems are solved, and transparency,
It was found that a polymer having excellent impact resistance and tear strength and having good blow moldability was obtained, and the present invention was completed.

That is, the present invention has at least one polymer block mainly containing a vinyl aromatic hydrocarbon and at least one polymer block mainly containing a conjugated diene, and the content of the vinyl aromatic hydrocarbon is 60. In the block copolymer mixture of more than 95% by weight and less than 95% by weight, the molecular weight of the main component is 30,000 to 23.
And the content of components with a molecular weight of 250,000 or more is 5
.About.50 wt.% Block copolymer mixture.

Hereinafter, the present invention will be described in detail.

The block copolymer constituting the block copolymer mixture of the present invention is mainly composed of at least one, preferably two or more polymer blocks mainly containing vinyl aromatic hydrocarbons and at least one conjugated diene. Polymer block. Examples of the method for producing such a block copolymer include, for example, JP-B-36-19286, JP-B-43-17979, JP-B-46-32415, JP-B-49-36957, and JP-B-48-2.
Japanese Patent Publication No. 423, Japanese Patent Publication No. 48-4106, Japanese Patent Publication No. 56-28925, Japanese Patent Publication No. 51-49567, Japanese Patent Publication No. 59-166518,
The method described in JP-A-60-186577 and the like can be mentioned. By these methods, the block copolymer has the general formula: (In the above formula, A is a polymer block mainly composed of vinyl aromatic hydrocarbons, and B is a polymer block mainly composed of a conjugated diene. The boundary between the A block and the B block is not always clearly distinguished. , And n is an integer greater than or equal to 1.) Or general formula (In the above formula, A and B are the same as above, and X is, for example, a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyhalogenated hydrocarbon, carboxylic acid ester, and polyvinyl compound. Or a residue of an initiator such as a polyfunctional organolithium compound, where m and n are integers of 1 or more.). In the above formula, the term "polymer block mainly containing vinyl aromatic hydrocarbon" means a copolymer block of vinyl aromatic hydrocarbon containing 50% by weight or more of vinyl aromatic hydrocarbon and a conjugated diene and / or vinyl. An aromatic hydrocarbon homopolymer block is shown, and a polymer block containing a conjugated diene as a main component means a copolymer block of a conjugated diene and a vinyl aromatic hydrocarbon containing the conjugated diene in an amount exceeding 50% by weight, and / or
Or a conjugated diene homopolymer block. The vinyl aromatic hydrocarbon in the copolymer block may be distributed uniformly or in a taper shape. Further, in the copolymer portion, a plurality of portions in which vinyl aromatic hydrocarbons are evenly distributed and / or a portion in which taper distribution is formed may coexist. The block copolymer used in the present invention may be any mixture of the block copolymers represented by the above general formula.

The block copolymer thus obtained has a vinyl aromatic hydrocarbon content of more than 60% by weight and 95% by weight or less, preferably 65 to 90% by weight. When the content of vinyl aromatic hydrocarbon is 60% by weight or less, the rigidity,
It is not preferable because it is inferior in blow moldability. Further, when the content of vinyl aromatic hydrocarbon exceeds 95% by weight, impact resistance,
It is not preferable because the tear strength is poor.

Examples of the vinyl aromatic hydrocarbon used in the method of the present invention are styrene, o-methylstyrene, p-methylstyrene, p
-Tert-butylstyrene, 1,3-dimethylstyrene, α
-Methyl styrene, vinyl naphthalene, vinyl anthracene, etc., but styrene is particularly common. These may be used alone or in combination of two or more.

The conjugated diene used in the present invention is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), and 2,3.
-Dimethyl-1,3-butadiene, 1,3-pentadiene, 1,
Although 3-hexadiene and the like are mentioned, particularly common ones are 1,3-butadiene and isoprene. These may be used alone or in combination of two or more.

The hydrocarbon solution used in the production of the block copolymer constituting the block copolymer mixture of the present invention includes butane, pentane, hexane, isopentane, heptane, octane, isooctane and other aliphatic hydrocarbons, cyclopentane and methylcyclo. Alicyclic hydrocarbons such as pentane, cyclohexane, methylcyclohexane and ethylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene can be used. These may be used alone or in combination of two or more. The organolithium compound is an organomonolithium compound in which one or more lithium atoms are bonded in the molecule, and examples thereof include ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert.
-Butyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium and the like. These may be used alone or in combination of two or more. In addition, polar compounds or randomization for the purpose of adjusting the polymerization rate, changing the microstructure of the polymerized conjugated diene part (ratio of cis, trans, vinyl) and adjusting the reactivity ratio of the conjugated diene and vinyl aromatic hydrocarbons. Agents can be used. As polar compounds and randomizing agents, ethers, amines, thioethers, phosphoramide,
Examples thereof include alkylbenzene sulfonate and potassium or sodium alkoxide. Examples of suitable ethers are dimethyl ether, diethyl ether, diphenyl ether and tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether. As the amines, tertiary amines such as trimethylamine, triethylamine, tetramethylethylenediamine, and cyclic tertiary amines can be used. Phosphines and phosphoramides include triphenylphosphine and hexamethylphosphoramide. Examples of the randomizing agent include potassium or sodium alkylbenzene sulfonate, potassium or sodium butoxide, and the like.

The polymerization temperature for preparing the above block polymer is generally -10 ° C to 150 ° C, preferably 40 ° C to 12 ° C.
It is 0 ° C. Although the time required for the polymerization varies depending on the conditions, it is usually within 48 hours, particularly preferably 0.5 to 10 hours. Further, it is desirable that the atmosphere of the polymerization system is replaced with an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is within the range of the above-mentioned polymerization temperature and is a pressure sufficient to maintain the monomer and the solvent in the liquid phase. Further, it is necessary to take care so that impurities such as water, oxygen, carbon dioxide, etc. that inactivate the catalyst and the living polymer are not mixed in the polymerization system.

The block copolymer constituting the block copolymer mixture of the present invention can have a polar group-containing atomic group bonded to at least one polymer chain end of the polymer. Here, the polar group-containing atomic group is nitrogen, oxygen, silicon, phosphorus, sulfur,
It means an atomic group containing at least one atom selected from tin. Specifically, a carboxyl group, a carbonyl group,
Thiocarbonyl group, acid halide group, acid anhydride group, carboxylic acid group, thiocarboxylic acid group, aldehyde group, thioaldehyde group, carboxylic acid ester group, amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, Phosphate ester group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothioneanate group, silicon halide group, alkoxy silicon group, tin halide group And an atomic group containing at least one polar group selected from an alkyltin group, a phenyltin group and the like.
More specifically, the terminal-modified polymer described in JP-A-62-86074 can be used. The amount of the terminal-treating agent used is 0.7 to 5 mol, preferably 0.9 to 2 mol, based on one atom equivalent of lithium metal at the end of the polymer. Although the reaction temperature and the reaction time can be adjusted over a wide range, the reaction temperature is usually 15 to 115 ° C. and the reaction time is usually 1 second to 3 hours.

The most significant feature of the present invention is that the main component of the block copolymer mixture has a molecular weight of 30,000 to 230,000, preferably 50,000 to 200,000, and a molecular weight of 250,000 or more, preferably 300,000 to 10
Content of 0,000 components is 5 to 50% by weight, preferably 7 to
It is 40% by weight, more preferably 10 to 35% by weight. When the molecular weight of the main component of the block copolymer mixture is less than 10,000, impact resistance is poor, and when it exceeds 230,000, fluidity is poor and blow moldability is poor, which is not preferable. If the content of the component having a molecular weight of 250,000 or more is less than 5% by weight, tear strength and blow moldability are poor, and if it exceeds 50% by weight, fluidity is poor and moldability is poor, which is not preferable. Here, the molecular weight is a value (number average molecular weight) obtained by measuring with a gel permeation chromatography (GPC) and using a calibration curve prepared using standard polystyrene commercially available for GPC. In the present invention, the main component means a component showing the maximum peak in the gel permeation chromatogram. The molecular weight of the main component means a value obtained by calculating the molecular weight of the main component peak in the gel permeation chromatogram with the above calibration curve.
The main component has a molecular weight of 30,000 to 230,000 and a molecular weight of 2
As a method for obtaining a block copolymer having 5 to 50% by weight of 50,000 or more components, a block copolymer having a molecular weight of 30,000 to 230,000 and a block copolymer having a molecular weight of 250,000 or more are used in the present invention. Or a block copolymer having a molecular weight of 30,000 to 230,000 was produced according to a conventional method, and the living polymer was coupled with a coupling agent having 2 or more functional groups and then coupled. Examples thereof include a method of adjusting the molecular weight and content of the polymer within the range specified in the present invention. As the coupling agent in the latter method, a compound having an epoxy group, an isocyanate group, an imino group, an aldehyde group, a ketone group, an ester group, an acid anhydride group, a halogen group or the like can be used. The ratio of the component having a molecular weight of 250,000 or more can be confirmed by comparing the area of the portion corresponding to the component in the gel permeation chromatogram with the area of the entire polymer.

In the block copolymer mixture of the present invention, the aliphatic double bond based on the conjugated diene in the polymer can be hydrogenated by a hydrogenation reaction at an arbitrary ratio, for example, 5 to 100%. The catalyst used in the hydrogenation reaction, (1) Ni, Pt, Pd,
A supported heterogeneous catalyst in which a metal such as Ru is supported on a carrier such as carbon, silica, alumina, diatomaceous earth, and (2) Ni, C
Organic acid salts such as o, Fe, Cr or acetylaton salts and organic A
Homogeneous catalysts such as so-called Ziegler-type catalysts using reducing agents such as, or so-called organic complex catalysts such as organic metal compounds such as Ru and Rh are known. As a specific method, JP-B-42-8704, JP-B-43-6636, or JP-A-59-133203, JP-A-60-220147, the method described in JP Hydrogenation can be carried out in the presence of a hydrogenation catalyst to obtain a hydrogenated product, and the hydrogenated polymer used in the present invention can be synthesized. At that time, the hydrogenation rate of the aliphatic double bond based on the conjugated diene in the polymer, the reaction temperature,
It can be controlled to an arbitrary value by adjusting the reaction time, the hydrogen supply amount, the catalyst amount and the like. In particular, in order to obtain a hydrogenated product excellent in weather resistance and heat aging resistance, it is recommended that the hydrogenation rate of the aliphatic double bond based on the conjugated diene is 80% or more, preferably 90% or more. . In this case, the water addition rate of the aromatic double bond based on the vinyl aromatic hydrocarbon is not particularly limited, but the hydrogenation rate is preferably 20% or less. The amount of unhydrogenated aliphatic double bonds contained in the hydrogenated polymer can be easily known by an infrared spectrometer, a nuclear magnetic resonance apparatus or the like.

Various additives can be added to the block copolymer resin of the present invention depending on the purpose. Suitable additives include 30 parts by weight or less of a coumarone-indene resin, a terpene resin, a softening agent such as oil, and a plasticizer. In addition, various stabilizers, pigments, antiblocking agents, antistatic agents,
Lubricants and the like can also be added. In addition, anti-blocking agent, lubricant,
Examples of the antistatic agent include fatty acid amide, ethylenebisstearamide, sorbitan monostearate, saturated fatty acid ester of aliphatic alcohol, pentaerythritol fatty acid ester, and the like.
t-Butylphenyl salicylate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2
-(2'-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,5-
The chemicals described in "Plastics and Rubber Additives Handbook" (Chemical Industry Co., Ltd.) such as bis- [5'-t-butylbenzoxazolyl- (2)] thiophene can be used. These are generally 0.01-5% by weight, preferably 0.1-
Used in the range of 2% by weight.

The block copolymer resin of the present invention can also be used in combination with other polymers. As such a polymer, a polymer of the vinyl aromatic hydrocarbon-based monomer, the vinyl aromatic hydrocarbon-based monomer and another vinyl monomer, for example, ethylene, propylene, butylene, vinyl chloride, vinylidene chloride, vinyl acetate, Acrylic acid esters such as methyl acrylate, methacrylic acid esters such as methyl methacrylate, copolymers with acrylonitrile, etc., rubber modified impact resistant styrene resin (HIPS), atarilonitrile-butadiene-styrene copolymer (ABS ), Methyl methacrylate-butadiene-styrene copolymer, polyphenylene ether resin, polyethylene, polypropylene, polycarbonate, polysulfone, polyamide, polyester, polyvinyl chloride, polymethacrylic acid ester and the like. Particularly suitable thermoplastic resins include polystyrene, polyparamethylstyrene, and styrene-α.
-Methylstyrene copolymer, styrene-methylmethacrylate copolymer, and HIPS.

〔The invention's effect〕

The block copolymer mixture of the present invention is transparent and has excellent impact resistance and tear strength, and can be used as a molding material for various molded products. That is, the block copolymer mixture of the present invention, as it is or after being colored, is processed by the same processing means as a usual thermoplastic resin, such as a sheet, an extrusion molded article such as a film, and vacuum molding, pressure molding or the like. It can be used in a wide range of container packaging materials such as molded articles thermoformed by the method, specifically, food container packaging, blister packaging material, packaging film for fruits and vegetables, confectionery. In addition, it can be used for applications in which ordinary general-purpose thermoplastic resins are used, such as in the fields of toys, daily necessities, food packaging containers, miscellaneous goods, and light electric parts by injection molding, blow molding, and the like. In particular, the block copolymer mixture of the present invention can be suitably used as a material for films and sheets utilizing excellent tear strength, and as a material for various blow-molded products utilizing superior blow moldability.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Examples 1 to 7 and Comparative Examples 1 to 6 The block copolymers shown in Table 1 were produced by a conventional method using n-BuLi in cyclohexane as a catalyst. Molecular weight is 25
The ratio of the components of 10,000 or more was adjusted by separately producing a block copolymer having the same polymer structure as the block copolymer of the main component and a molecular weight of about 400,000 and blending it.

Next, a film having a thickness of 0.07 mm was formed by using a 30 mmφ inflation film forming machine. The characteristics of the obtained film and the moldability during molding are shown in Table 1.

Examples 8 to 11 and Comparative Examples 7 to 11 The block copolymer mixtures used in Table 1 were each extruded into a molten parison with a cylinder temperature of 200 ° C., and the parison was placed in a split mold to obtain a chest mean wall. Thickness 0.3 mm,
A cylindrical bottle having an internal volume of 200 cc was molded. The moldability of these bottles during molding is shown in Table 2.

Although the block copolymer mixture M could be blow molded, the molded product had extremely poor impact resistance.

Example 12 n-Butyllithium was obtained as a catalyst in cyclohexane. Styrene content 75% by weight, the main component molecular weight is 15
The epoxidized soybean oil is added to a solution of a living polymer of a block copolymer having an ABA structure, and a part of the living polymer is coupled to give a molecular weight of 2
A block copolymer mixture having a proportion of 50,000 or more components of 15% by weight was obtained. The resulting block copolymer mixture showed the same performance as the block copolymer mixture D.

Claims (1)

[Claims] 1. A polymer block mainly containing at least one vinyl aromatic hydrocarbon and a polymer block mainly containing at least one conjugated diene, wherein the content of the vinyl aromatic hydrocarbon is 60% by weight. In the block copolymer mixture of more than 95% by weight, the component showing the maximum peak in the gel permeation chromatogram has a molecular weight of 30,000 to 230,000, and the content of the component having a molecular weight of 250,000 or more is 5 to 5%. A block copolymer mixture which is 50% by weight.