JPS60248731A - Production of high molecular weight polyamide - Google Patents

Abstract

PURPOSE:To produce the titled polyamide having excellent heat-resistance without lowering the characteristics of the polyamide, in high productivity, by reacting an essentially linear polyamide with a specific amount of a bisoxazoline compound and a specific amount of a copper compound in molten state. CONSTITUTION:The objective polyamine can be produced by adding (A) 0.05- 10wt%, preferably 0.1-8wt% bisoxazoline compound [e.g. 2,2'-methylenebis(2- oxazoline), etc.] and (B) 1-1,000ppm (in terms of copper) of a copper compound (preferably copper acetate or cuprous iodide) to (C) an essentially linear polyamide (e.g. nylon 6), and reacting the components with each other in molten state.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention does not reduce the properties of polyamide,
The present invention relates to a highly productive method for producing high molecular weight polyamide.

(Prior Art) Polyamides such as nylon 6 and nylon 66 have excellent properties and are widely used as fibers, films, and other molded products.

By the way, in the production of fibers for industrial materials such as tire cords,
In particular, high molecular weight polyamide is required, but in order to obtain high molecular weight polyamide, it is necessary to proceed with polymerization at high temperature for a long time, which tends to cause thermal deterioration (gelation) of the polyamide and has poor productivity. There was a problem.

As a method to obtain high molecular weight polymers in a short time.

There is a method using a chain binding agent, and it is known that a high molecular weight polyester with excellent heat resistance can be obtained by adding a bisoxazoline compound as a chain binding agent to a polyester such as polyethylene terephthalate and reacting it with the terminal carboxyl group. (For example, Japanese Patent Application Laid-Open No. 50-59525
No. 56-91009, etc.).

The present inventors investigated the application of this method to polyamide, which is a polymer also having terminal carboxyl groups, and found that polyamide behaves differently from polyester, and that in nylon 6, the degree of polymerization is opposite. decreases,
In the case of nylon 66, the polymer turned yellow and the heat resistance and crystallinity decreased (see Japanese Patent Laid-Open No. 136622/1982).

(Objective of the Invention) The present invention uses a bisoxazinone-based chain binder without reducing the properties of polyamide.

The object of the present invention is to provide a method for producing high-molecular-weight polyamide with excellent heat resistance with good productivity.

(Structure of the Invention) As a result of intensive research to achieve this purpose, the present inventor has
The inventors have discovered that preferable results can be obtained by reacting a bisoxazoline compound with a polyamide in the presence of a copper compound, and have thus arrived at the present invention.

That is, the gist of the present invention is as follows.

a substantially linear fusible polyamide and 0.05 to 10% by weight of a bisoxazoline compound in an amount of 1 to 110% by weight as copper;
1. A method for producing a high molecular weight polyamide, which comprises reacting in a molten state in the presence of 00 pp of a copper compound.

Specific examples of polyamide in the present invention include:

Nylon 6, nylon 11. Nylon 12. nylon 4
6, nylon 66, nylon 610. Examples include fusible polyamides such as polymethaxylylene adipamide, nylon 66/polyhexamethylene terephthalamide copolymer, and nylon 66/polyparaphenylene terephthalamide copolymer.

The bisoxazoline compound in the present invention is represented by the following general formula.

(R is a divalent organic group, n is an integer of O or 1.

In the formula, the hydrogen atom may be substituted with an alkyl group or an aryl group. ) Specific examples of the bisoxazoline compound represented by this general formula include 2.2'-methylenebis(2-oxazoline), 2.2'-ethylenebis(2-oxazoline), 2.2'-ethylenebis( 4-methyl-2-oxazoline), 2.2'-propylenebis(2-oxazoline), 2.2''-tetramethylenebis(2
-oxazoline), 2.2'-hexamethylenebis(2-oxazoline), 2.2'-octamethylenebis(2-oxazoline)+2+2'-p-phenylenebis(2-oxazoline), 2.2''- p-phenylenebis(4-methyl-2-oxazoline), 2.2
"-p-phenylenebis(4,4-dimethyl-2-oxazoline), 2.2"-p-phenylenebis(4-
phenyl-2-oxazoline), 2+2'm-phenylenebis(2-oxazoline), 2.2''-m-phenylenebis(4-methyl-2-oxazoline).

2 + 2' m-phenylenebis(4,4-dimethyl-2-oxazoline), 2.2''-m-phenylenebis(4-phenyl-2-oxapurine), 2.
2'-o-phenylenebis(2-oxazoline)
, 2.2'-.

-phenylenebis(4-methyl-2-oxazoline)
, 2,2°-bis(2-oxazoline), 2,2′-
Bis(4-methyl-2-oxazoline), 2.2'
-bis(4-ethyl-2-oxazoline), 2.2
'-'bis(4-phenyl-2-oxazoline) and the like can be mentioned.

9 Specific examples of the copper compounds in the present invention include copper acetate, cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, copper phthalate, and stearic acid. Complex salts of copper, copper pyrophosphate, etc., and various copper salts and organic compounds 1 For example, 8-
Oxyquinoline copper.

Copper complex salts of 2-mercaptobenzimidazole, etc.
- Copper acetate and cuprous iodide are preferred. These may be used alone or in combination of two or more.

In the present invention, the amount of bisoxazoline compound added is 0.
．． 05 to 10% by weight, preferably 0.1 to 8% by weight, and the amount of copper compound added is 1 to 11,000% by weight as copper.
pp is appropriate. If the amount is too small, the molecular weight increasing effect will be insufficient, and if the amount is too large, the properties of the polyamide will be impaired.

The reaction between the polyamide and the bisoxazoline compound can be carried out by adding and reacting the bisoxazoline compound in the polyamide melt polymerization step or melt molding step. The simplest method is to add a bisoxazoline compound to a polyamide chip and allow it to react during melt molding.

The copper compound is preferably added at the same time as or before the addition of the bisoxazoline compound, and only the copper compound is added at the time of polymerization of the polyamide.

A method of adding a bisoxazoline compound during molding may be adopted.

It goes without saying that other additives such as heat-resistant agents, matting agents, coloring agents, extenders, flame retardants, antistatic agents, modifiers, etc. may be added during melt polymerization or molding. Nor.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples. Note that the relative viscosity ηr is 1 g of polymer mixed with 100 ml of 96% sulfuric acid.
It is a value measured at 25°C for a solution dissolved in , and the units of carboxyl group COOH and amino group NH2 are equivalent/106 g polymer.

Example 1 ε-caprolactam was continuously polymerized by a conventional method, chipped, refined, and dried to obtain ηr of 3.40. Moisture content 0.
0.08% chips were obtained.

This chip was mixed with 'l,2'-m-phenylenebis(2-oxazoline) MBO and cuprous iodide C in the amounts shown in Table 1.
uI was added, a 40n+mφ extruder type melt spinning machine was used, the melting temperature was 280℃, and the discharge amount was 80g.
/min or spinning at 160g/min, 400m/m
The yarn was wound up at a speed of 1.5 in to obtain an undrawn yarn.

Regarding the obtained undrawn yarn, ηr, C0OH and NO3
The results of measuring the amounts are shown in Table 1.

Table 1 As is clear from Table 1, when only a bisoxazoline compound is added to nylon 6, the viscosity decreases, but when a copper compound is added together, the viscosity increases and favorable results are obtained.

Example 2 ηr2゜86. Using nylon 66 chips with a moisture content of 0.09%, the melting temperature was 290°C and the discharge amount was 120g/mi.
As n, spinning was carried out in the same manner as in Example 1 to obtain an undrawn yarn.

Table 2 shows the characteristic values of the obtained undrawn yarn.

Table 2 As is clear from Table 2, in the case of nylon 66.

It can be seen that when only a bisoxazoline compound is added, a slight increase in viscosity is observed and the undrawn yarn is colored, but when a copper compound is added, the viscosity increases significantly and no coloration occurs.

Example 3 Nylon 66 salt and p-phenylenediamine/terephthalic acid (mixture with a molar ratio of 1/1) were melt-polymerized at a molar ratio of 80:20, and the melting point was 258°C, 77r2.45.
Copolyamide chips of C00H52 and No. 228 were obtained.

The dried chips (moisture content: 0.05%) were placed in a glass tube equipped with a stirrer and melted at 283°C in an NZ atmosphere.

2.2'-p-phenylenebis(2-oxazoline)P
BO or MBO and Cur were added and samples were taken at the time shown in Table 3 to examine changes in characteristic values.

The results are shown in Table 3.

Table 3 Table 3 (Continued) As is clear from Table 3, in the case of this copolyamide, the viscosity increases even when only the bisoxazoline compound is added, but when a copper compound is added in combination, the viscosity increases quickly with the addition of a smaller amount. It can be seen that it increases and then stabilizes.

(Effects of the Invention) As described above, according to the two methods of the present invention, it is possible to produce a high molecular weight polyamide with good productivity without deteriorating the properties of the polyamide.

Patent applicant: Unitika Co., Ltd.

Claims (1)

[Claims] (1) Substantially linear fusible polyamide and 0.05 to 10% by weight of a bisoxazoline compound as copper
A method for producing a high molecular weight polyamide, which comprises reacting in a molten state in the presence of ~11,000 pp of a copper compound.