JP3187912B2 - Styrene-based thermoplastic elastomer composition and molded article thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrenic thermoplastic elastomer composition and a molded article thereof. More specifically, the present invention relates to a composition in which the styrene-based thermoplastic elastomer has improved blocking properties, and a molded article produced from the composition.

[0002]

2. Description of the Related Art A styrene-based thermoplastic elastomer has a polystyrene block as both end blocks and a block such as a polybutadiene block, a polyisoprene block or a polyethylene / polybutylene block as an intermediate block. Since they are incompatible, the polystyrene blocks are uniformly dispersed in the molecule and are linked to each other by the intermediate block, and there is no chemical crosslinking.However, the polystyrene block fixes the end of the intermediate block, and the physical crosslinking network Thus, at room temperature, the rubber exhibits rubber elasticity similar to that of the vulcanized rubber, and the polystyrene block is melted by heating to exhibit thermoplasticity. For this reason, styrene-based thermoplastic elastomers have processing advantages (no need for a mastication step, no vulcanization step, are soluble in a wide range of solvents, have low viscosity, and can be processed in the same manner as general thermoplastics. Compatibility with various types of compounds, easy compounding, etc.), physical properties (high strength, high elasticity, low temperature properties, acid resistance, alkali resistance,
Ozone resistance, oxidation resistance, ultraviolet resistance, heat resistance, etc.) and are used in a wide range of fields.

[0003] However, styrene-based thermoplastic elastomers include raw material pellets and various molded products produced therefrom cause blocking between the pellets or between products, so that the raw material pellets have poor fluidity or are removed from the packaging bag. There are problems such as difficulty in handling the product due to difficulty in bridging in the storage hopper, and inconvenience in processes such as storage, distribution, molding and use.

[0004] As described above, styrene-based thermoplastic elastomers have excellent physical properties, but are severely blocked. To solve this problem, a method of blending or coating a wax has conventionally been adopted. Is undesirable because it bleeds on the surface of the molded article or impairs the physical properties of the molded article.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such a situation, and has improved the blocking property without using a wax while maintaining excellent physical properties of a styrene-based thermoplastic elastomer. It is an object to provide a styrene-based thermoplastic elastomer composition.

[0006]

Means for Solving the Problems The inventors of the present invention carried out experiments by blending various compounds to improve the blocking property of a styrene-based thermoplastic elastomer, and found that a specific polymer and an organic peroxide were blended. It has been found that the above problems can be solved in such a case, and the present invention has been completed.

That is, according to the present invention, 100 parts by weight of a styrene-based thermoplastic elastomer, 0.1 to 100 parts by weight of a polyolefin-modified polysiloxane and 0.1 to 100 parts by weight of an organic peroxide are used.
The present invention relates to a styrene-based thermoplastic elastomer composition comprising 001 to 1 part by weight.

[0008] The present invention further relates to a molded article produced from the styrene-based thermoplastic elastomer composition.
In the present invention, a molded article is not particularly limited, but a sheet,
Films, tubes, plates, sticks, and other shaped articles, such as medical and food supplies, such as syringe gaskets, milk tubes, vending machine tubes, packing and medicine stoppers, and automotive supplies such as front end grills, bumper end caps , Side moldings, crash panels,
Steering wheel cover, electrical system connector, gasket, grommet and heat duct connector, etc.
Electric wire coating products such as battery cable jackets, welding cable jackets, automotive primer wires, appliance wires, flexible cords, connectors, plugs, and wiring in equipment, etc., as well as agricultural and waterproof sheets, daily necessities, sporting goods, Leisure products, health products, civil engineering construction products, marine and marine products, aerospace products, textile and textile products, sanitary products, and other molded products.

In the present invention, the styrene-based thermoplastic elastomer is obtained by copolymerizing styrene and butadiene by anionic polymerization, cationic polymerization, coordination polymerization, radical polymerization, solution polymerization, emulsion polymerization, or the like. It means a block copolymer or a polymer obtained by hydrogenating these to eliminate unsaturated double bonds in a polymer chain. Specific examples include those having the following trade names: Tufprene A (a styrene-butadiene linear block copolymer manufactured by Asahi Kasei Kogyo), Sorbrene T-411 (a styrene-butadiene block copolymer manufactured by Nippon Elastomer), Kraton D -1101 (manufactured by Shell Chemical Co., styrene-butadiene-styrene block copolymer) and the like, and tuftec (manufactured by Asahi Kasei Corporation) obtained by hydrogenating them
Clayton G (manufactured by Shell Chemical), Lavalon (manufactured by Mitsubishi Yuka) and the like. These styrenic thermoplastic elastomers
Part of styrene may be substituted with α-methylstyrene, vinyltoluene, pt-butylstyrene, etc. Similarly, part of butadiene may be substituted with isoprene, 1,3-pentadiene, 2,3-dimethyl- It may be substituted with 1,3-butadiene or the like.

In the present invention, the polyolefin-modified polysiloxane is a copolymer having a polyolefin unit and a polysiloxane unit in a molecule, and a polyolefin-based resin and an organopolysiloxane are kneaded by heating and grafted. The kneaded materials obtained as described above are typical ones, and their production methods are described in Japanese Patent Application Nos. 63-42218 and 63-1076, which were previously filed by the present inventors.
No. 16, No. 63-150118, No. 63-20722
No. 1, 63-215972, 63-305185
No., Japanese Patent Application No. 1-154699, No. 1-54700,
This is described in detail in JP-A-2-171142 and the like.

The polyolefin resin, which is one component of the polyolefin-modified polysiloxane, is a polymer containing ethylene or propylene as a main component. Examples of the ethylene-based polymer include high-pressure polyethylene, linear low-density polyethylene (LLDPE), and ultra-low-density polyethylene (VLD).
PE), ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene- Examples include methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer (EEA), ethylene-ethyl methacrylate copolymer, ethylene-vinyl alcohol copolymer, and the like. The propylene-based polymer is usually Ziegler-Natta. Using a known α-olefin stereoregular catalyst such as a type catalyst, propylene homopolymer obtained by polymerizing propylene or propylene as a main component, propylene and other α-olefins, for example, ethylene, butene-1, 4
-Methylpentene-1, hexene-1, heptene-1,
It is a random copolymer with octene-1 or the like, specifically, propylene homopolymer, ethylene-propylene copolymer, propylene-butene-1 copolymer, ethylene-
A propylene-butene-1 terpolymer can be used.

The organopolysiloxane which is the other component of the polyolefin-modified polysiloxane includes, for example, the following formula I: (Wherein, R ¹ represents an aliphatic unsaturated group, for example, a vinyl group, an allyl group, an isopropenyl group, an acryl group or a methacryl group, and R ² represents an unsubstituted or substituted monovalent carbon having no aliphatic unsaturated group. Hydrogen group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, aliphatic hydrocarbon group such as hexyl group, phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, benzyl group, phenethyl group, Represents an aromatic hydrocarbon group such as a styryl group, an alicyclic hydrocarbon group such as a cyclohexyl group or a cyclobutyl group, and a and b represent the following conditions: 0 <a <1, 0.5 <b <3, 1 < a + b <3
(Representing a numerical value that satisfies). Examples of the polysiloxane include vinylmethyl-dimethylpolysiloxane, vinylmethyl-phenylmethyl-dimethylpolysiloxane, and the like.

In the present invention, the compounding amount of the polyolefin-modified polysiloxane is 0.1 to 100 parts by weight based on 100 parts by weight of the styrene thermoplastic elastomer. This is because if the amount is less than 0.1 part by weight, the effect of preventing the blocking property is not exhibited, and if the amount is more than 100 parts by weight, no improvement in the effect can be expected and there is no economic efficiency.

The organic peroxide which can be used in the present invention preferably has a decomposition temperature of 100 to 220 ° C. with a half-life of 10 minutes, ie, a half-life (Tp) of 100 to 220 ° C. for 10 minutes. Examples thereof include the following (where the decomposition temperature (° C.) is shown in parentheses): t-butylperoxyisopropyl carbonate (135), t-butylperoxylaurate (140), 2,5- Dimethyl-2,5-di (benzoylperoxy) hexane (140), t-butylperoxyacetate (140), di-t-butyldiperoxyphthalate (140), t-butylperoxymaleic acid (140), cyclohexanone peroxide ( 1
45), t-butyl peroxybenzoate (14
5), dicumyl peroxide (150), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (155), t-butylcumyl peroxide (15)
5), t-butyl hydroperoxide (158), di-
t-butyl peroxide (160), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3
(170), di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (1
80), 2,5-dimethylhexane-2,5-dihydroperoxide (213).

In the present invention, the amount of the organic peroxide is 0.001 to 1 part by weight based on 100 parts by weight of the styrene thermoplastic elastomer. If the amount is less than 0.001 part by weight, the modification reaction is insufficient, the blocking resistance and the mechanical strength are poor, and if it exceeds 1 part by weight, the gel increases, and the processability and the surface of the molded article become uneven. Depending on what happens and is undesirable.

The styrenic thermoplastic elastomer composition of the present invention may contain various conventional auxiliary materials in the resin composition. The auxiliary material includes a stabilizer, an antioxidant, a filler, a colorant, carbon black, a lubricant, a processability improver, and an antistatic agent.

The styrenic thermoplastic elastomer composition of the present invention comprises a styrenic thermoplastic elastomer,
The compounding components of the polyolefin-modified polysiloxane and the organic peroxide, and if necessary, the above-mentioned various auxiliary materials, are added. Can be manufactured. The mixing order of each component may be arbitrary, and a trace addition component such as an antioxidant and an antistatic agent may be added after preparing a high-concentration masterbatch with a styrene-based thermoplastic elastomer in advance. The above-mentioned various molded articles can be obtained from the obtained styrene-based thermoplastic elastomer composition by an injection molding method, an extrusion molding method, a rotational molding method, a compression molding method or the like.

[0018]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples, and those embodying the technical idea of the present invention are within the scope of the present invention. Contained within. In the following examples, “parts” means “parts by weight”.

In the following examples, the measurement of the melt index (MI) is based on the condition 4 in Table 1 of JIS K7201.
The measurement of tensile strength and elongation is based on JIS
Performed at speed H according to K7113. The blocking value was 10 cm × 10 c manufactured from the composition under test.
2 × 1 mm sheets, 4kg at 23 ℃
And then left for 24 hours with a load of 8 mm using a blocking tester (TA-3623, manufactured by Sokki Keiso).
/ Min. The smaller the blocking value (g), the better the blocking resistance.

Example 1 A styrene-ethylene-butene-1-styrene block copolymer (SEB) was used as a styrene-based thermoplastic elastomer.
S) (trade name Lavalon 5301C, manufactured by Mitsubishi Yuka) 100
10 parts of polyethylene-modified polysiloxane (trade name: Silgraft 210, manufactured by Nippon Unicar) and 1,3-di (t-butylperoxyisopropyl) benzene (trade name: perbutyl P, manufactured by NOF Corporation) .03 parts of a kneader type HAAKE SYSYEM
The mixture was kneaded at 160 ° C. for 15 minutes by using No. 40 to obtain a kneaded material.

Example 2 SEBS (trade name: Lavalon 5301C, manufactured by Mitsubishi Yuka) 1
00 parts, MI 0.70 g / 10 min EVA-modified polysiloxane (trade name: Silgraft 150, manufactured by Nippon Unicar)
10 parts and 1,3-di (t-butylperoxyisopropyl) benzene (trade name: Perbutyl P, manufactured by NOF Corporation)
0.03 parts are kneader type HAAKE SYSEM40
By kneading at 160 ° C. for 15 minutes to obtain a kneaded product.

Example 3 EE of 100 parts of SEBS (trade name: Kaliflex TR KX65S, manufactured by Shell Chemical), MI 0.84 g / 10 min
10 parts of A-modified polysiloxane (trade name: Silgraft 310, manufactured by Nippon Unicar) and 0.03 part of 1,3-di (t-butylperoxyisopropyl) benzene (trade name: perbutyl P, manufactured by NOF Corporation) are kneader-type HAAKE
The mixture was kneaded at 160 ° C. for 15 minutes with SYSYEM40 to obtain a kneaded product.

Example 4 EE of 100 parts of SEBS (trade name: Kaliflex TR KX65S, manufactured by Shell Chemical), MI 0.84 g / 10 min
40 parts of A-modified polysiloxane (trade name: Silgraft 310, manufactured by Nippon Unicar) and 0.03 part of 1,3-di (t-butylperoxyisopropyl) benzene (trade name: perbutyl P, manufactured by NOF Corporation) are kneader-type HAAKE
The mixture was kneaded at 160 ° C. for 15 minutes with SYSYEM40 to obtain a kneaded product.

Comparative Example 1 The physical properties of SEBS (trade name Lavalon 5301C, manufactured by Mitsubishi Yuka) were measured in the same manner.

Comparative Example 2 The physical properties of SEBS (trade name: Kaliflex TR KX65S, manufactured by Shell Chemical) were measured in the same manner.

Comparative Example 3 SEBS (trade name: Lavalon 5301C, manufactured by Mitsubishi Yuka) 1
00 parts and 10 parts of a polyethylene-modified polysiloxane (trade name: Silgraft 210, manufactured by Nippon Unicar) having an MI of 0.52 g / 10 minutes were mixed with a kneader type HAAKE SYSYE.
The mixture was kneaded with M40 at 160 ° C. for 15 minutes to obtain a kneaded product.

Comparative Example 4 SEBS (trade name: Lavalon 5301C, manufactured by Mitsubishi Yuka) 1
00 parts and 10 parts of an EVA-modified polysiloxane (trade name: Silgraft 150, manufactured by Nippon Unicar) having an MI of 0.70 g / 10 minutes were kneaded with a kneader-type HAAKE SYSEM40.
By kneading at 160 ° C. for 15 minutes to obtain a kneaded product.

Comparative Example 5 100 parts of SEBS (trade name: Kaliflex TR KX65S, manufactured by Shell Chemical) and an EEA-modified polysiloxane (trade name: Silgraft 31) having an MI of 0.84 g / 10 min.
0, made by Nippon Unicar) 10 parts kneader type HAAKE
The mixture was kneaded at 160 ° C. for 15 minutes with SYSYEM40 to obtain a kneaded product.

Table 1 shows the physical properties of the kneaded materials obtained in Examples 1 to 4 and Comparative Examples 3 to 5 and the measurement results of Comparative Examples 1 and 2.

[0030]

[Table 1]

[0031]

As described in detail above, the styrenic thermoplastic elastomer composition of the present invention has the excellent advantages of the styrenic thermoplastic elastomer itself, that is, good processability (no need for a mastication step, additional processing). Eliminates the need for a sulfurizing process, is soluble in a wide range of solvents, has low viscosity, can be processed in the same manner as general thermoplastics, is compatible with many types of compounds, is easy to compound, and has excellent physical properties (high Strength, high elasticity, low-temperature properties, acid resistance, alkali resistance, ozone resistance, oxidation resistance, ultraviolet resistance, heat resistance, etc.) and improved blocking properties which have been a problem in the past. Moreover, according to the composition of the present invention, bleeding or the like does not occur on the surface of the molded product when wax is used for imparting blocking resistance.

Accordingly, the present invention provides a molded article having improved blocking resistance without causing bleeding on the surface,
It has become possible to provide food supplies, automobile supplies, electric wire covering products, daily necessities, sports goods, leisure goods, health goods, civil engineering construction goods, marine marine goods, aerospace goods, textile and textile goods, sanitary goods, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 53/00-53/02 C08K 5/14 C08L 51/06-51/08

Claims (2)

(57) [Claims] 1. Styrene-based thermoplastic elastomer 100
Parts by weight, polyolefin-modified polysiloxane 0.1 to 1
A styrene-based thermoplastic elastomer composition comprising 00 parts by weight and 0.001 to 1 part by weight of an organic peroxide. 2. A molded article produced from the styrenic thermoplastic elastomer composition according to claim 1.