JPH0674363B2 - Rubber-modified thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a rubber-modified thermoplastic resin composition which has improved falling weight impact strength and the like and is excellent in weather resistance and impact resistance.

b. Conventional technology Using an ethylene-α-olefin copolymer as a rubber component,
A copolymer obtained by graft-polymerizing styrene, acrylonitrile, or the like (hereinafter referred to as AES resin) is known as a resin having excellent weather resistance and impact resistance.

However, this AES resin has a drawback that although the notched Izod impact strength is excellent, the falling weight impact strength is inferior.

c. Problems to be Solved by the Invention As a result of intensive studies on the improvement of the above-mentioned drawbacks, the present inventors have found that an aromatic vinyl-conjugated diene block copolymer having a specific structure in an AES resin in a specific ratio. By blending them, we succeeded in obtaining an AES resin excellent in drop weight impact strength, and arrived at the present invention.

d. Means for Solving the Problems That is, the present invention relates to a monomer containing an aromatic vinyl compound and / or a vinyl cyanide compound as a main component in the presence of an ethylene-α-olefin copolymer rubber. A graft copolymer obtained by graft copolymerizing
0.1 to 10% by weight based on α-olefin copolymer rubber
The present invention provides a rubber-modified thermoplastic resin composition containing the aromatic vinyl-conjugated diene block copolymer or its hydride.

The aromatic vinyl-conjugated diene block copolymer used in the present invention comprises at least one block, preferably at least two aromatic vinyl monomer-based blocks, and at least one conjugated diene monomer. Is a block copolymer having a block mainly composed of

Further, a hydrogenated product of the above block copolymer may be used, which is preferable in terms of excellent weather resistance. Further, a graft copolymer of a vinyl compound such as aromatic vinyl or vinyl cyanide to the above block copolymer, or a block copolymer containing a modified functional group can also be used.

The polymer block mainly composed of the aromatic vinyl monomer preferably has an aromatic vinyl hydrocarbon content of more than 50% by weight, more preferably 70% by weight or more.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, and the like, and particularly common one is styrene.

The polymer block mainly composed of the conjugated diene is a polymer block having a conjugated diene content of 50% by weight, preferably 70% by weight or more.

Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, and 1,3-pentadiene, and particularly common examples include 1,3-butadiene and isoprene.

The content of the aromatic vinyl monomer in the aromatic vinyl-conjugated diene block copolymer is preferably 40 to 95% by weight, more preferably 60 to 80% by weight. If it is less than 40% by weight or exceeds 95% by weight, the falling weight impact strength is lowered, which is not preferable.

The number average molecular weight of the aromatic vinyl polymer block contained in the copolymer chain of the aromatic vinyl-conjugated diene block copolymer is preferably 10,000 to 150,000, more preferably 20,000 to 100,000.

The rubber-modified thermoplastic resin composition of the present invention comprises an aromatic vinyl in the presence of an ethylene-α-olefin copolymer rubber such as an ethylene-propylene copolymer or an ethylene-propylene-conjugated diene copolymer. A graft copolymer obtained by copolymerizing a compound and a monomer mixture containing a vinyl cyanide compound as a main component, or a resin composition comprising the copolymer of the compound and the monomer mixture.

The content of the above-mentioned ethylene-α-olefin-based copolymer in the graft copolymer or the resin composition is preferably 3
˜70% by weight, more preferably 5 to 50% by weight, particularly preferably 5 to 40% by weight.

As a method for producing the AES resin, various methods of radical polymerization with a vinyl monomer in the presence of rubber, for example, bulk polymerization method, solution polymerization method, suspension polymerization method, emulsion polymerization method, bulk suspension polymerization method, etc. Can be manufactured.

The aromatic vinyl compound used as a monomer is styrene, α-methylstyrene, p-methylstyrene, or the like.

The vinyl cyanide compound is acrylonitrile, methacrylonitrile, etc., and vinyl compounds copolymerizable therewith, for example, acrylic acid esters such as methyl acrylate and methyl methacrylate, N-phenylmaleimide, N-cyclohexylmaleimide. Maleimides such as, and unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride can also be used in combination.

In producing the rubber-modified thermoplastic resin composition of the present invention,
Even if the aromatic vinyl-conjugated diene block copolymer is mixed in any of the following steps, the effect of improving the drop weight impact strength can be obtained. It is preferable in terms of the point, and the further method is particularly preferable because a composition having more excellent gloss of the molded product can be obtained.

That is, it is mixed with an ethylene-α-olefin rubber before graft polymerization. It is mixed (dissolved) with an aromatic vinyl monomer before graft polymerization or a monomer mixture containing an aromatic vinyl monomer as a main component.
Mixing with the polymer solution after graft polymerization It is possible to use a method such as adding to the graft polymer and mixing with an extruder or the like (can also be mixed with antioxidants, light stabilizers, pigments and other resins at once).

The blending amount of the aromatic vinyl-conjugated diene block copolymer with respect to the AES resin is 0.1 to 10% by weight, preferably 0.2 to 5% by weight with respect to the ethylene-α-olefin copolymer rubber component.
% By weight.

At 0.1% by weight or less, improvement in falling weight impact strength was not observed, and
If it exceeds 0% by weight, the improvement effect is saturated and the weather resistance is deteriorated.

When using the thermoplastic resin composition of the present invention, glass fiber, carbon fiber, metal fiber, glass beads, asbestos,
Fillers such as wollastonite, calcium carbonate, talc and barium sulfate can be used alone or in combination.

Among these fillers, glass fibers and carbon fibers preferably have a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more.

In addition, known additives such as flame retardants, antioxidants, plasticizers, colorants and lubricants can be added and used.

Depending on the performance required further, other polymers, for example,
Polyethylene, polypropylene, BR, NBR, SBR, hydrogenated S-
BS, polystyrene, AS resin, HIPS, ABS resin, AES resin, polysulfone, polyether sulfone, N-phenylmaleimide copolymer styrene resin, MBS, methyl methacrylate-styrene copolymer, SIS block copolymer, polyimide , PPS, polyether ether ketone,
Vinylidene fluoride polymerization, polyamide, polyamide elastomer, polyester elastomer PPE resin and the like can be appropriately blended.

The rubber-modified thermoplastic resin composition of the present invention can be used by molding into various molded articles by injection molding, sheet extrusion, vacuum molding, profile molding, foam molding, or the like.

Various molded products obtained by the above molding method, by utilizing their excellent properties, automobile exteriors, interior members and electricity,
It can be used for various electronic products and housings.

e. Examples Next, the present invention will be specifically described with reference to Examples.

Example-1 10 Autoclave reactor, 20 parts by weight of ethylene-α-olefin rubber, block copolymer (JSR TR2400) 0.
Charge 2 parts by weight, styrene 56 parts by weight, acrylonitrile 24 parts by weight, toluene 100 parts by weight, stir at 50 ° C. until the rubber is completely dissolved, t-dodecyl mercaptan 0.2 parts by weight, t-butyl peroxyisopropyl carbonate 0.5.
After adding parts by weight, a polymerization reaction was carried out at 100 ° C. for 10 hours. After depolymerizing the polymerization product by a conventional method and drying,
0.4 parts by weight of 2,2-methylenebis- (4-ethyl-6-t-butylphenol) was added and pelletized by using an extruder, and then a test piece was prepared by injection molding, and its physical properties were measured.

Examples 2 to 11 Graft copolymers were prepared in the same manner as in Example 1 except that the type and amount of the block copolymer, the mixing method, and the composition of the monomer components were changed as shown in Table 1. Prepare the resin,
Its physical properties were measured. The results are shown in Table-1.

Comparative Examples 1 to 4 A graft polymerization copolymer resin was prepared in the same manner as in Example 1 except that the block copolymer was not blended, and its physical properties were measured. The results are shown in Table-1.

Comparative Examples 5 to 6 A resin composition was prepared in the same manner as in Example 1 except that a graft polybutadiene rubber (BR 02 LL manufactured by Nippon Synthetic Rubber Co., Ltd.) was used as a rubber component, and its physical properties were measured.
The results are shown in Table-1.

Comparative Examples 7 to 9 A resin composition was prepared in the same manner as in Example 1 except that the amount or type of the block copolymer was changed as shown in Table-1, and the physical properties thereof were measured. The results are shown in Table-1.

From the results of Table-1, it is clear that the rubber-modified thermoplastic resin composition of the present invention obtained by blending the aromatic vinyl-conjugated diene block copolymer is excellent in drop weight impact strength.

f. Effect of the Invention The rubber-modified thermoplastic resin composition of the present invention is
It has a greater drop impact strength than S resin, and a great industrial utility value as a resin with excellent weather resistance and impact resistance.

Claims (4)

[Claims] 1. A graft copolymer obtained by graft-copolymerizing a monomer containing an aromatic vinyl compound and / or a vinyl cyanide compound in the presence of an ethylene-α-olefin copolymer rubber. And 0.1 to 10 wt% of the aromatic vinyl-conjugated diene block copolymer or its hydride with respect to the above ethylene-α-olefin copolymer rubber, a rubber-modified thermoplastic resin. Resin composition. 2. The structure of an aromatic vinyl-conjugated diene block copolymer has at least one aromatic vinyl polymer block and at least one conjugated diene-based polymer block, and further, aromatic vinyl and conjugated diene. Weight ratio with 40: 6
The rubber-modified thermoplastic resin composition according to claim 1, which is 0 to 95: 5. 3. A rubber-modified thermoplastic resin composition according to claim 1, wherein the ethylene-α-olefin-based rubber or monomer before graft copolymerization is premixed with a block copolymer. object. 4. The rubber-modified thermoplastic resin composition according to claim 1, wherein the block copolymer is mixed with the polymer after grafting.