JPS6026422B2 - Thermoplastic resin composition for melt molding containing polyamide resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition for melt molding which has good moldability and is composed of a nitrile copolymer and a polyamide polymer.

It has been known that nitrile copolymers containing or not containing rubbery polymers have high gas barrier properties, transparency, and good mechanical properties, and have attracted attention as useful packaging materials. However, due to the high melt viscosity of nitrile copolymers, moldability is not sufficient.

In order to solve this problem, it is known to improve moldability by using a large amount of alkyl mercaptans or other molecular weight regulators during polymerization, or by adding a large amount of lubricant.
However, although these methods improve moldability, they also pose problems such as a decrease in mechanical strength and a decrease in gas barrier properties, and when a large amount of mercaptans is used, the mercaptans remain in the resin, making them undesirable. yields no results. As a result of intensive research to obtain a nitrile copolymer material with excellent moldability that does not have such drawbacks, the present inventors found that a composition of a nitrile copolymer and a polyamide polymer is suitable for this purpose. Heading This invention has been achieved.

The present invention has 50 ethylenically unsaturated nitrile compound units.
A nitrile copolymer obtained by blending the above nitrile copolymer with a nitrile copolymer or a rubber-like polymer containing ~9% by weight, or by graft copolymerizing an ethylenically unsaturated nitrile compound with a rubber-like polymer. The present invention relates to a thermoplastic resin composition for melt molding, which has excellent mechanical properties, gas barrier properties, transparency, and good moldability, and is composed of 70 to 9% by weight of a polymer and 1 to 3% by weight of a polyamide polymer. be.

The nitrile copolymer according to the present invention has the general formula R
represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom.

It is a copolymer consisting of 50 to 9 weight % of Q,8-olefinically unsaturated mononitrile units represented by the formula and 50 to 1 weight % of other monomer units copolymerizable therewith.

Examples of ethylenically unsaturated nitrile compounds include acrylonitrile, methacrylonitrile, ethacrylonitrile, Q-chloroacrylonitrile, Q-fluoroacrylonitrile, and others.

Among these, acrylonitrile and methacrylonitrile are particularly preferred. Suitable other monomers that can be copolymerized with this include acrylic acid ester, methacrylic acid ester, alkyl vinyl ether/aromatic vinyl compound, isobutene, etc. Suitable specific examples include methyl acrylate, acrylic acid ester, etc. These include ethyl acid, butyl acrylate, methyl methacrylate, methyl pinyl ether, ethyl vinyl ether, butyl vinyl ether, styrene, methylstyrene, isobutene, and others. Such a nitrile copolymer may be produced by any method as long as it is produced for the purpose of being a thermoplastic polymer for molding.

The above-mentioned nitrile copolymer may contain a rubbery polymer in order to impart impact resistance. A method of blending, a method of graft copolymerizing ethylenically unsaturated nitrile compounds in the presence of a rubbery polymer, a method of blending the graft copolymer and a nitrile copolymer, or any other suitable method. Adopted. Suitable rubbery polymers include diene rubber, acrylic ester rubber, olefin rubber, urethane rubber, and mixtures thereof. The amount of these rubber-like polymers is arbitrary depending on the purpose, but in order not to significantly impair the properties of the nitrile copolymer, it should not exceed 5% by weight based on the total amount with the nitrile copolymer. , preferably 2% by weight or less. Examples of the polyamide polymer used in the present invention include nylon 6, nylon 60, nylon 61, nylon 11, nylon 12, and others.

In particular, among polyamide polymers, those having a melting point of 25 mm or lower are preferred, and nylon 6, for example, is particularly preferred. When the amount of the polyamide polymer used is less than 1% by weight, the effect of improving moldability is poor, and when it exceeds 3% by weight, impact resistance may decrease. Therefore, the amount of polyamide polymer used is preferably 1 to 3% by weight, especially 3 to 1% by weight.
5% by weight is preferred. The polyamide polymer is a single type,
Alternatively, two or more kinds may be used, and the shape thereof may be any one such as a solution, an aqueous dispersion, a powder, and a beret. The method of mixing the nitrile copolymer and the polyamide polymer according to the present invention may be any of the commonly used methods, such as melt kneading, solution blending, aqueous dispersion blending, and the like.

When forming the desired molded product by injection molding, extrusion molding, etc., methods using heated rolls, Banbury mixers, extruders, kneader blenders, etc. are suitable.
The mixing may be carried out at any time from the polymerization reaction of the nitrile copolymer to the time of final molding. The composition thus obtained has good moldability without impairing the excellent properties of the nitrile copolymer, and can be produced into films, sheets, bottles, and other useful materials using general molding machines. It is possible.

The present invention will be explained below by way of examples.

All references to % below mean % by weight. The nitrile-based copolymer used in the examples was an aqueous dispersion produced by emulsion graft polymerization of 60% acrylonitrile, 20% styrene, and 10% methyl methacrylate in the presence of 10% styrene-butadiene synthetic rubber Larax. It was obtained by post-treating the liquid using a conventional method. Example 1 The above nitrile copolymer and nylon 6 (manufactured by Ube Industries, Ltd.)
Ube Nylon 1011) was mixed in a Henschel mixer, then made into a pellet in an extruder heated to 2WC, and
A test piece was obtained by injection molding at 380 mm.

The Izod impact value was measured using a 1/4 inch thick test piece with a /t mark and 2s0. Fluidity is the amount of resin that passes through the nozzle on the diameter 1 side at 240°C. The results are shown in Table 1. Table 1 As shown in Table 1, the addition of polyamide (nylon 6) significantly improves flowability, but does not improve mechanical strength or transparency.

Example 2 As in Example 1, a nitrile copolymer and nylon 6 were blended, but in this example, methyl methacrylate-ptadiene-styrene copolymer [manufactured by Kanebuchi Chemical Co., Ltd., MB] was also blended.
S resin (Kanese B-Matsu)] was added at the same time.

Claims (1)

[Claims] 1. 50 to 90 ethylenically unsaturated nitrile compound units
Nitrile copolymer 70 obtained by blending the above nitrile copolymer with a nitrile copolymer or rubber-like polymer containing % by weight, or by graft copolymerizing an ethylenically unsaturated nitrile compound with a rubber-like polymer. A thermoplastic resin composition for melt molding, comprising ~99% by weight and 1-30% by weight of a polyamide resin. 2 Ethylenically unsaturated nitrile compound units are represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom.) The thermoplastic resin composition for melt molding according to claim 1, which is an α,β-olefinically unsaturated mononitrile unit. 3. Claim 1, in which the content of the rubbery polymer is 50% by weight or less based on the total content of the nitrile copolymer.
The thermoplastic resin composition for melt molding as described in 2.