JPS63182344A - Production of polyether-ester-amide elastomer - Google Patents

Abstract

PURPOSE:To produce the title elastomer excellent in moldability, abrasion resistance and elastic properties, by reacting a specified polyamide with a specified polyoxyalkylene glycol under specified conditions and completing the reaction in a high vacuum. CONSTITUTION:Adipic acid is reacted with nylon 66 salt to obtain a polyamide of an average-MW of 300-5,000, having carboxyl groups on both ends. This polyamide is molten by heating at 200-260 deg.C for 30-60min in a nitrogen atmosphere and a polyoxyalkylene glycol in an amount equimolar to said polyamide is added to the melt and reacted with forced agitation in the presence of a catalyst (e.g., tetrabutyl titanate) under an atmospheric pressure until the terminal carboxyl group content in this reaction system is decreased to 50-10% of that before the start of the reaction. After the pressure in the reaction system is decreased to a high vacuum <=5mmHg over a period of 10-30min, the reaction is completed at 220-300 deg.C to obtain a polyether-ester-amide in which the nylon 66 chain constitutes a hard segment and the polyoxyalkylene chain constitutes a soft segment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a polyetheresteramide elastomer. More specifically, the present invention relates to a method for producing a polyetheresteramide elastomer having excellent heat resistance and elastic properties, in which the hard segment is a nylon 66 chain and the soft segment is a polyoxyalkylene chain.

Polyether ester amide elastomer has excellent moldability and excellent properties as an elastic body, such as abrasion resistance and sound-dampening properties, so it is attracting attention as an en-cnearing resin.

[Conventional technology]

The method for producing polyether ester amide elastomer involves first making a polyamide having carboxyl groups at both ends from cucarzene acid and a nylon salt or lactam, and then melting this monoamide and substantially equimolar I-lyoxyalkylene glycol. A method of polycondensation is known.

(Japanese Patent Publication No. 56-45419) In general, polyamide, which is a hard segment, and polyoxyalkylene glycol, which is a soft segment, have poor compatibility, and the melt polycondensation described above is not satisfactory, but only in the case of specific polyamides. It was not possible to obtain a suitable degree of polymerization. Therefore, the actual upper fabric is nylon 12.
Most of the polyether ester amide elastomers are produced by linking units and polyoxytetramethene glycol units with ester bonds. This nylon 12-based polyetheresteramide elastomer has excellent properties such as cold resistance, abrasion resistance, and flexibility, but it also has problems such as a low melting point, poor heat resistance, and a low elastic recovery rate. are doing.

In particular, the elastic strength decreases significantly in the high temperature range of 100°C or higher, and the reality is that it cannot be used at all at temperatures of 120°C or higher.

Studies on preether ester amide elastomers that use highly heat-resistant nylon 66 as the polyamide component have been conducted for a long time, but when nylon 66 is used as the amide component, it is highly compatible with polyoxyalkylene glycol, which is a soft segment. However, conventional melt polycondensation cannot produce a polymer with a satisfactory degree of polymerization, and U.S. Patent No. 3,044
, 987, a polyether ester amide elastomer containing nylon 66 as a polyamide component was obtained by changing the terminal of dicarzene acid to an acid chloride group to increase reactivity and carrying out solution polymerization in an organic solvent.

However, both the acid chloride method and the solution polymerization method cause high costs, significantly increasing the cost of the polymer, and are extremely disadvantageous industrially.

[Problem that the invention seeks to solve]

In order to keep the cost of polymers low, it is necessary to perform polycondensation by a melt polymerization method instead of using the acid chloride method and the solution polymerization method, which are disadvantageous in terms of cost.

An object of the present invention is to provide a method for inexpensively producing a polyetheresteramide elastomer with excellent heat resistance and elastic properties by linking nylon 66 chains and polyoxyalkylene chains with ester bonds through melt polycondensation. That's true.

[Means for solving problems]

The present invention deals with the reaction of a polyamide having carboxyl groups at both ends with a polyoxyalkylene glycol,
The above problem was solved by stirring and mixing under normal pressure to allow sufficient reaction until the amount of Cal I end groups in the reaction system reached a constant value, and then placing the reaction system under high vacuum to complete the reaction.

That is, in the present invention, the node segment is made of nylon 66 chain,
In a method for producing a polyether ester amide elastomer in which the left segment is a polyoxyalkylene chain, a polyamide having carboxyl groups at both ends is formed from adipic acid and nylon 66 salt, and then the polyamide and polyoxyalkylene glycol are melted. After the amount of Cal I end groups in the reactant reaches 50% to 10% of the amount before the start of the reaction, the reaction system is placed under high vacuum to complete the reaction. This is a method for producing a characteristic polyetheresteramide elastomer.

To manufacture the polyether ester amide elastomer of the present invention, first, a polyamide having carboxyl groups at both ends (hereinafter referred to as dicarzene acid polyamide) is prepared from adipic acid and hexamethylene azide gumide (nylon 66 salt). adjust.

This dicarzenic acid polyamide can be easily prepared by a known method.
It can be adjusted. For example, adipic acid, nylon 66 salt, and water are placed in a pressurized autoclave at 270°C.
It can be adjusted by reacting under conditions of 17.5 h/car. At this time, the average molecular weight of the polyamide can be adjusted by changing the amount of adipic acid relative to the nylon 66 salt. The average molecular weight of the polyamide is 300～
5000, preferably 800 to 3000 is used.

Generally, polyoxytetramethylene glycol (hereinafter referred to as PTMG) is preferably used as the polyalkylene glycol used in the present invention, and its average molecular weight is 30.
0 to soo o, preferably 500 to 3000, is preferably used from the viewpoint of elastic properties. In addition, in order to improve the compatibility with polyamide, polyalkylene glycol can be partially replaced with polyoxyethylene chains, such as PTM.
G may also be used.

In the polycondensation of the present invention, dicarzene acid polyamide is first charged into a reaction system, and heated to about 30°C at 200 to 260°C under a nitrogen atmosphere.
Heat for ~60 minutes to melt. Next, substantially equimolar amounts of polyalkylene glycol as dicarzenic acid polyamide are added with stirring. Here, the polyalkylene glycol does not need to be added all at once, and may be added in divided portions as appropriate.

After adding the polyalkylene glycol, the reaction system is heated and stirred under a nitrogen atmosphere at normal pressure until the amount of carbo terminal groups in the reaction system becomes 50% to 10% of the amount before the start of the reaction to allow a sufficient reaction. The reaction system is then brought into a vacuum system for about 10-30 minutes,
Preferably, the temperature is raised to 220 to 300 DEG C. at a temperature of 5 wHg or less, preferably 1 mHg or less, and polymerization is carried out under these polymerization conditions until an I lima of a predetermined viscosity is obtained. At this point, it is time to put the reaction system under high vacuum, but as shown above, the amount of carbo terminal groups in the reaction system is 50% of that before the start of the reaction.
normal pressure until it reaches ~10 cm, preferably 35% to 15%,
It is necessary to carry out the reaction after heating and stirring under a nitrogen atmosphere to cause a sufficient reaction.

If high vacuum is entered before the amount of carboxyl end groups in the reaction system reaches 50 units before the reaction starts, there will be dicarboxylic acid polyamide that has not yet reacted with the polyalkylene glycol in the system, and this dicarboxylic acid polyamide will be exposed to high vacuum. By doing so, it decomposes rapidly, the molar lance collapses, and polymerization hardly progresses.

On the other hand, if the reaction is carried out under normal pressure for a long period of time until the amount of carbo terminal groups in the reaction system is reduced to 10% or less of the amount before the start of the reaction, a phenomenon such as gelation of the polyamide begins to occur in some parts, which is not preferable.

In the polymerization reaction of the polyether ester amide elastomer of the present invention, a titanium-based catalyst such as a tetraalkyl titanate such as tetrazotyl titanate, a titanium metal salt of oxalate such as potassium titanium oxalate, dibutyltin oxide, dibutyltin laurate, monobutyltin oxide tin-based catalysts, zirconium tetrabutoxide, zirconium tetraalkoxide-based catalysts,
Hafnium tetraalkoxide catalysts such as hafnium tetraethoxide and lead catalysts such as lead acetate are preferably used. These compounds promote polymerization and reaction as catalysts, and are advantageous in easily producing the colorless, highly polymerized polymer of the present invention, which has excellent physical properties. The catalyst can be used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight of the total amount of the reaction mixture.

In addition, the polyether ester amide elastomer of the present invention may contain heat and light resistance stabilizers such as antioxidants, thermal decomposition inhibitors, hydrolysis resistance improvers, and ultraviolet absorbers during polymerization or after polymerization and before molding. Can be done.

The degree of polymerization of the polyether ester amide elastomer of the present invention varies depending on the use, purpose, and molding method, but it is 1.5 in terms of solution relative viscosity (ηr) measured in orthochlorophenol at 35°C. In particular, K should preferably be 1.7 or more.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 100 g (0,685 mol) of adipic acid and 538 g (1053 mol) of nylon 66 salt prepared from hexamethylene diamine and adipic acid were charged into a pressurized autoclave with 30 Og of water, and the pressure was 17.5 Kq/cm.
, the average molecular weight was 8 by reacting at 270°C for 2 hours.
95 dicarboxylic acid polyamides were prepared.

200 g (0,2235 mol) of this dicarboxylic acid polyamide was mixed with N,N'-hexamethylene-bis(3,5-di-t-butyl-4-hydrocinnamide) (antioxidant: trade name, Irganox 1098). ) and 0.8 g into a reaction vessel equipped with a stirring blade, and stirred with N and A diluted for 2
After heating and stirring at 40°C for 1 hour to melt the dicarboxylic acid polyamide, the average molecule f1oo.

5 g (0,2235 mol) of PTMG 22λ and 2 g of tetrabutyl titanate α as a catalyst were added, and then 2
The temperature was raised to 50°C and the mixture was stirred under normal pressure for about 3 hours. At this time, the amount of carbo terminal groups in the reaction system was 285 meq/Kp, which was 27 meq/Kp before the start of the reaction.

Then, according to the temperature increase and pressure reduction program, 270℃, 0.5
The polymerization conditions were brought to sw+Hg or less. Under this condition 3
After time reaction, a viscous and uniform melt/lima was obtained. When this polymer was discharged into water in the form of a strand, it became a flexible strand with no stickiness. The obtained polymer had a relative viscosity (ηr) of 1.72 measured in orthochlorophenol at 35°C at 0.51 elf, and had a DSCK
The crystal melting point (Tm) IIi was 250°C. Note that in the following examples and comparative examples, ηr and Tm are also determined by this method.

The mechanical properties of the nine test pieces molded using a small injection molding machine are as shown in Table 1, and they were flexible and had elasticity, and showed excellent mechanical strength even at high temperatures.

Example 2 145.28 g of PTMG (α223
A polymer was obtained by polymerization in the same manner as in Example 1, except that 5 mol) was used. The ηr of this polymer is 1.78, and Tm
The temperature was 252°C. As for the mechanical properties, as shown in Table 1, similar to Example 1, it exhibited excellent mechanical strength even at high temperatures.

[Comparative Example 1] Polymerization was carried out in the same manner as in Example 1 except that the normal pressure time after adding PTMG was changed to 1 hour. Even after stirring for 6 hours, the viscosity did not increase and a polymer with no elasticity was obtained.

At this time, the amount of carbo terminal groups in the reaction system before entering the high vacuum was 685 meq/)C9, and it was completed within 65 hours before the start of the reaction.

Comparative Example 2 21.5 g (1.0 mol) of aminododecanoic acid, 325 g (0.5 mol) of polyoxytetramethylene glycol with a number average molecular weight of 41 aso and 115 g of dodecadiic acid.
('0.5 mol) was charged into a reaction vessel equipped with a stirring blade, and heated and stirred at 230°C for 1 hour while purging with N2 to make a homogeneous solution.
The polymerization conditions were 0° C. and 0.5 sw+Hg or less.

When reacted under these conditions for 4 hours, a viscous and uniform molten polymer was obtained. Polymerization was carried out in the same manner as in Example 1 to obtain a polymer.゛The ηr of this polymer was 1.75, and the Tm was 140°C. As shown in Table IK, the mechanical properties deteriorate at low to normal temperatures, but the strength decreases significantly at high temperatures, and at 120C
It almost flowed.

Table 1 [Effects of the Invention] The present invention makes it possible to melt polyether ester amide elastomers consisting of nylon 66 chains for the node segments and polyoxyalkylene chains for the soft segments without using organic solvents, which was previously difficult. It became possible to produce it by polycondensation. In addition, the 8-tooth manufacturing plant, which uses acid chloride as a raw material and is expensive, has disappeared. As a result, manufacturing costs can be kept low.

In addition, since the polyether ester amide elastomer of the present invention uses nylon 66 chains in the node segment, it has a high melting point and has slightly superior high temperature properties compared to the nylon 12-based polyether ester amide elastomer. It can be made into a diasteromer.

Claims (1)

[Claims] In a method for producing a polyether ester amide elastomer in which the hard segment is a nylon 66 chain and the soft segment is a polyoxyalkylene chain, a polyamide having carboxyl groups at both ends is formed from adipic acid and a nylon 66 salt, and then this polyamide and Polyoxyalkylene glycol is forcibly mixed and reacted in a molten state under normal pressure, and after the amount of carbo terminal groups in the reactant reaches 50% to 10% of the amount before the start of the reaction, the reaction system is placed under high vacuum. A method for producing a polyetheresteramide elastomer characterized by completing the reaction