JPS59164359A - Production of impact-resistant polyamide - Google Patents

Abstract

PURPOSE:To produce the titled polyamide, by blending a modified polyolefin copolymer rubber with a polyamide contg. end amino groups at a specified concn. CONSTITUTION:A modified polyolefin copolymer rubber obtd. by melt-kneading an alpha,beta-unsaturated carboxylic acid (derivative) such as acrylic acid with a polyolefin copolymer rubber such as an ethylene/propylene copolymer rubber having an ethylene unit content of 30-90mol%, is used. 5-100pts.wt. said copolymer rubber is melt-kneaded with 100pts.wt. polyamide contg. end amino groups at a concn. of the least 5.5X10<-5>equivalent/g.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing polyamide 7 having excellent impact resistance.

In general, polyamide has excellent abrasion resistance, electrical properties, heat resistance, and mechanical strength, and is widely used as an engineering resin for various mechanical parts materials, but it has the drawback of not having sufficient surface protection properties. There is.

Conventionally, various studies have been conducted on methods for improving the impact resistance of polyamide, and a typical example thereof is a method of blending an ethylene copolymer with polyamide.

The inventors of the present invention have conducted extensive research with the aim of developing a method that improves the impact resistance of polyamides compared to conventionally known methods. As a result, they found that the object can be achieved when a specific amount of a modified polyolefin copolymer comb is blended into a polyamide having a specific concentration of terminal amine groups, and the present invention has been completed.

In other words, in the present invention, the terminal amine group concentration is 5.5 x 10-
5 equivalents/100 parts by weight of polyamide of 7 or more.

It consists of adding 5 to 100 parts by weight of a variable polyolefin copolymer rubber and melt-kneading. The present invention provides a new method for producing polyamide with extremely excellent impact resistance.

Specific examples of polyamides used in the present invention include nylon 6, nylon 11. Polylactums such as nylon 12, nylon 66, nylon 610. Polyamides obtained from dicarboxylic acids such as nylon 612 and amines, nylon 6,/66+ nylon 6,/6
10. Nylon 6/12, Vylon 6/612. Nylon 6/66/6101 Nylon 6/66/12.
Examples include copolymerized polyamides such as nylon 6/6T (T: terephthalic acid component), polyesteramides, polyetheramides, polyesteretheramides, and mixtures thereof.

In the present invention, among these polyamides, those having a terminal amine group concentration of 5.5 X 10'-5 equivalents/g or more are used, and there is no particular restriction on the upper limit of the concentration.
For example, it can be used even if all the terminal groups are amine groups. In addition, in the case of a polyamide in which the concentration of terminal amine groups is lower than the above value, impact resistance cannot be improved even if modified polyolefin copolymer rubber is blended.

The polyamide having an amine terminal group in the present invention can be easily prepared by adding an appropriate amount of a chain transfer agent such as metax-sorylenediamine, baraxylylenediamine, hexamethylenediamine, dodecamethylenediamine, etc. during pentapolymerization. .

The modified polyolefin copolymer combs used in the present invention are polyolefin copolymer combs.

It is produced by melt-kneading α,β-unsaturated oxycarboxylic acid or its derivative and peroxide at a temperature of 150 to 300°C.

Examples of polyolefin copolymer combs include copolymers of ethylene, fluoropylene, butene-1, and hexene-1. Among these, it is preferable to use an ethylene copolymer rubber having an ethylene unit content of 30 to 90 mol, particularly 50 to 85 mol.

The α,β-unsaturated carboxylic acid or its derivatives are used for modifying these polyolefin copolymer rubbers and are grafted onto the copolymer rubbers.

Monocarboxylic acids such as acrylic acid and methacrylic acid.

Examples include dicarboxylic acids such as maleic acid and fumaric acid, and their anhydrides. Examples of peroxides that can be used include benzoyl peroxide, α, α'-bis-t-butyl peroxide, p-diisopropylbenzene, and the like, which are decomposed during melt-kneading.

Note that the terminal amino group concentration is 5.5 x 10-5 equivalents/
The reason why the combination of polyamide 7 or higher and modified polyolefin copolymer rubber exhibits high impact strength is not clear. But that's one reason.

When polyolefin copolymer rubbers are modified using α, β unsaturated carboxylic acids or their derivatives and peroxides, all of the α, β unsaturated carboxylic acids or their derivatives are The 20 to 50 groups are not grafted to the polyolefin copolymer and remain as unreacted substances in the modified polyolefin copolymer combs, and the remaining α, β unsaturated carboxylic acid or its derivative forms the terminal amine group of the polyamide. It is thought that this is due to the reaction.

The concentration of terminal amine groups is 5,5 x 10-5 equivalents/7
There are no particular limitations on the method of melt-kneading the above polyamide and modified olefin copolymer rubber.

For example, a modified olefin copolymer rubber may be added to polyamide that is still in a molten state after one polymerization reaction and melt-kneaded, or it may be added to powdered or pelleted polyamide and melt-kneaded. It's okay.

The vorticity during melt-kneading is usually 200-320°C, preferably 240-320°C. In addition, during the melt-kneading process, dyes and pigments may be added depending on the purpose.

Fillers, nucleating agents, fibrous materials, plasticizers, lubricants, 2 foaming agents.

Appropriate amounts of heat resistant agents, weather resistant agents, flame retardants, etc. may be added.

The impact-resistant polyamides produced in the present invention can be used, for example, in films, sheets, pipes, and tubes.

It can be processed into rods, injection molded products, etc.

Next, an example of the present invention and a comparative example will be given.

The modified polyolefin copolymer rubber used on each side was manufactured by the following method.

Production of modified polyurethane copolymer rubber: Ethylene 79
100 parts by weight of polyolefin copolymer rubber containing 29 moles of topropylene.

After triblending 0.5 parts by weight of maleic anhydride and 0.3 parts by weight of benzoyl peroxide.

- Axial extruder (resin temperature, 23'0'C', discharge t'j:
2 Kg/hr), and the maleic anhydride content was 0.
．． A modified polyolefin copolymer comb grafted with 32 parts by weight was obtained.

Example 1 The terminal amine group concentration is 8.50 x 10-5 equivalent/7° relative viscosity (-6810 for J Engineering S-, the same applies hereinafter) is 2.
After tri-blending 70 parts by weight of polyamide (nylon 6) of No. 80 and 30 parts by weight of modified polyolefin copolymer comb, the mixture was melt-kneaded using a twin-screw extruder (resin temperature 250°C, output rate 4 min/hr). death.

Got a beret. Next, this pellet was dried under reduced pressure and then molded into an Izod impact test piece using an injection molding machine. The Izot impact strength of the molded product is determined by ASTλ1-D-25.
6 (Targeting 10 1/2 inch test pieces with notches)
Measurement was carried out according to the measurement temperature 23'(:') 17. The results are shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1, except that 70 parts by weight of nylon 66 shown in Table 1 was used as the polyamide. The results are shown in Table 1.

Comparative Examples 1 to 4 As the polyamide, 70% each of the various nylons shown in Table 1 were used.
An experiment was conducted in the same manner as in Example 1, except that parts by weight were used. The results are shown in Table 1.

Table 1 Examples - Example 1. The amount of polyamide used is 80 parts by weight,
An experiment was conducted in the same manner as in Example 1, except that the amount of modified polyolefin copolymer used was changed to 20 parts by weight.

As a result, the Izot impact strength of the molded product was 80·c.
nt/cm.

Patent applicant Ube Industries Co., Ltd. -4:

Claims (1)

[Claims] 5 to 100 parts by weight of a modified polyolefin copolymer rubber is added to 100 parts by weight of a polyamide having a terminal amine group concentration of 5.5 x 10 equivalents/7 or more. A method for producing impact-resistant polyamide, which is characterized by melt-kneading.