JP2875346B2 - Method for producing polyamideimide elastomer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a method for producing a polyamideimide elastomer having heat resistance and transparency.
More specifically, the present invention relates to a molding material requiring particularly flexibility and transparency, for example, a hard segment made of polyamideimide suitable as a material for hoses, tubes, sheets, and the like, and a polyoxyalkylene glycol, α, ω The present invention relates to a method for efficiently producing a flexible and transparent polyamide-imide elastomer having a high strength and excellent heat resistance containing a soft segment comprising dihydroxy hydrocarbon.

2. Description of the Related Art In recent years, thermoplastic elastomers such as polyamide elastomers and polyester elastomers have excellent physical properties such as water resistance, heat resistance, mechanical strength, and low-temperature properties, and are easy to mold, and can be expected to improve productivity. Therefore, they are rapidly being used in applications such as industrial parts, sheets, and hoses.

Among the thermoplastic elastomers, as the polyamide elastomer, a polyetheresteramide type or a polyetheramide type is known, and as the polyamide component, nylon such as 12-nylon or 6-nylon is used. At present, mainly 12-nylon-based products are on the market. On the other hand, as the polyether component, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, a mixture thereof, a block copolymer, or the like is used. Among these, water resistance, mechanical strength, and low temperature are used. In terms of characteristics and the like, polyoxytetramethylene glycol is mainly used.

As a polyamide elastomer comprising this polyoxytetramethylene glycol as a polyether component,
For example, as a hard segment, an elastomer using a polyamide having 4 to 14 carbon atoms between amide groups (Japanese Patent Publication No.
No. 45419, Japanese Patent Publication No. 58-11459), an elastomer using a polyamide having 9 or more carbon atoms between amide groups as a hard segment (Japanese Patent Publication No. 57-24808), and ε-aminocaproic acid as a hard segment. Using polycapramides derived from
No. 21095).

Incidentally, the compatibility between polyamide and polyoxytetramethylene glycol is low, and in particular, the compatibility between polyamide having a high amide density, for example, 6-nylon and polyoxytetramethylene glycol is low. This compatibility decreases as the molecular weights of the two increase, and coarse phase separation occurs during the polymerization, and the resulting polyamide elastomer becomes milky white and opaque and has poor mechanical strength. Therefore,
When 6-nylon is used as the hard segment, a transparent and high-strength polyamide elastomer is hardly obtained by the above method.

On the other hand, 12-nylon having a low amide density is relatively compatible with polyoxytetramethylene glycol, and has improved transparency and strength as compared with the case of using 6-nylon. Translucent ones can also be obtained. However, if the polyamide content constituting the hard segment is reduced in order to obtain a soft elastomer having a low hardness, the cohesive force of the polyamide domain is sharply reduced, resulting in a material having low mechanical strength and a heat resistance having a low melting point. Inferior to For this reason, the 12-nylon-based polyamide elastomers that have been practically used are mainly relatively hard with a Shore hardness of 40D to 70D, and are excellent in flexibility and toughness, transparency and heat resistance. A 12-nylon polyamide elastomer is not yet known.

On the other hand, in order to increase the compatibility at the time of polymerization and to improve the heat resistance of the obtained elastomer, aminocarboxylic acid, trimellitic anhydride and polyetherdiamine are reacted to form a hard segment and a soft segment with an imide bond or Elastomers linked by amide bonds have been proposed (JP-A-60-158222). However, in this method, the raw material polyetherdiamine is difficult to obtain, and a complicated process is required for the production, so that industrialization is difficult and the cost is disadvantageously inevitable.

Further, by simultaneously reacting caprolactam, polyoxytetramethylene glycol and dicarboxylic acid and polymerizing while maintaining the water content in the reaction system at 0.1 to 1.0% by weight, a transparent and tough material having improved compatibility is obtained. Although some elastomers have been proposed (JP-A-61-247732 and JP-A-62-70422), these elastomers are improved in terms of flexibility but are not necessarily sufficient in terms of heat resistance. Not really.

By the way, when a polyamide elastomer is used as a resin modifier which is one of its main uses, it is required that the polyamide elastomer has heat resistance, is easily kneaded, and has good flowability during injection molding. For this reason, it is necessary to change the melting point or crystallization temperature of the elastomer according to the partner resin, but such a polyamide elastomer has not been known so far.

Therefore, obtaining industrially easily available and inexpensive caprolactam as the main polyamide component to obtain a polyamide elastomer excellent in transparency, mechanical strength, heat resistance and resin modifying property is extremely industrial value. Although it is expensive, it has not yet been realized.

Problem to be Solved by the Invention Under such circumstances, the present invention includes caprolactam as a main amide component, flexibility, mechanical strength,
An object of the present invention is to provide a transparent polyamide elastomer excellent in heat resistance and resin modifying property.

Means for Solving the Problems The present inventors have conducted intensive studies to develop polyamide-based elastomers having such preferable properties, and as a result, have found that caprolactam and a trivalent compound capable of forming at least one imide ring in a specific ratio can be obtained. Or, by polymerizing a tetravalent aromatic carboxylic acid or an acid anhydride thereof, an organic diisocyanate compound, a polyoxyalkylene glycol or an α, ω-dihydroxy hydrocarbon under specific conditions,
A polyamideimide containing an imide ring obtained from caprolactam and the aromatic polycarboxylic acid or an acid anhydride thereof and an organic diisocyanate is used as a hard segment, and a polyamideimide elastomer having the glycol as a soft segment can be obtained. In the case of producing a hydrophilic polyamide-imide elastomer using polyoxyethylene glycol as the alkylene glycol, the polymer is easily colored, and the longer it is exposed to a temperature of 200 to 300 ° C., the more easily it becomes colored. By polymerizing under specific conditions, it was found that the polymerization was completed in a short time and an elastomer with little coloring was obtained, and based on this finding, the present invention was completed.

That is, the present invention relates to (A) caprolactam, (B)
Trivalent or tetravalent aromatic polycarboxylic acid capable of forming at least one imide ring or an acid anhydride thereof, (C) an organic diisocyanate compound and (D) a number average molecular weight of 500
~ 4000 polyoxyalkylene glycol and α, ω-
At least one glycol selected from dihydroxy hydrocarbons, as well as [However, b, c and d are each a component (B),
(Representing the number of moles of the components (C) and (D))] to produce the polyamide-imide elastomer under the conditions satisfying the relationship of (A), (B) and (C). B) reacting the oligomer with the component to form a polyamide-imide oligomer. The oligomer is mixed with the component (D) in the presence of caprolactam at least 0.2% by weight of the oligomer while removing water produced by the reaction. Polymerized at a temperature of 200-300 ° C,
Next, unreacted caprolactam is removed, and if necessary, post-polymerization is performed under reduced pressure at a temperature of 200 to 300 ° C. or the components (B) and (D) are reacted in advance to form a polyester oligomer. After that, the components (A) and (C) are added to the oligomer, and while removing water generated by the reaction, the mixture is heated at 200 to 300 ° C.
And a method of producing a polyamide-imide elastomer, which is characterized by carrying out post-polymerization under reduced pressure at a temperature of from 200 to 300 ° C. in some cases.

 Hereinafter, the present invention will be described in detail.

In the method of the present invention, the amount of caprolactam used as the component (A) of the raw material is not particularly limited, but in order to obtain a transparent, heat-resistant, and tough elastomer, the amount of It is advantageous to use 10 to 65% by weight, preferably 20 to 60% by weight. The amount of caprolactam used is appropriately selected depending on the hardness and other physical properties of the target elastomer, or the composition and molecular weight of the soft segment to be used.

The hard segment of the polyamide-imide elastomer in the present invention comprises caprolactam (A) and (B)
Component (C) is derived from a polyamideimide dicarboxylic acid formed by reacting a trivalent or tetravalent aromatic polycarboxylic acid or an acid anhydride thereof capable of forming at least one imide ring with an organic diisocyanate compound as the component (C). You. At this time, at least two of the three carboxyl groups of the trivalent aromatic polycarboxylic acid, that is, the aromatic tricarboxylic acid, are bonded to adjacent positions on the aromatic ring, and are reacted with caprolactam or an organic diisocyanate compound to form one. And four carboxyl groups of a tetravalent aromatic polycarboxylic acid, ie, an aromatic tetracarboxylic acid,
Two of each must be capable of bonding to adjacent positions of the aromatic ring to form two imide rings by reaction with caprolactam or an organic diisocyanate compound.

Such aromatic tricarboxylic acids include, for example, 1,
2,4-trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, 2,6,7-naphthalenetricarboxylic acid, 3,3 ', 4-diphenyltricarboxylic acid, benzophenone-3,3', 4-tricarboxylic acid Diphenylsulfone-3,3 ', 4-tricarboxylic acid, diphenylether-3,3', 4-tricarboxylic acid and the like.Examples of aromatic tetracarboxylic acids include, for example, pyromellitic acid, diphenyl-2,2 ′, 3,
3'-tetracarboxylic acid, benzophenone-2,2 ', 3,3'
-Tetracarboxylic acid, diphenylsulfone-2,2 ', 3,
3'-tetracarboxylic acid, diphenyl ether-2,2 ',
3,3'-tetracarboxylic acid and the like. In the present invention, acid anhydrides of these polycarboxylic acids can also be used.

Further, the organic diisocyanate compound of the component (C) reacts with a carboxyl group to form an amide or imide. By using such an organic diisocyanate compound, the hard segment has a structure containing an imide ring portion and a repeating unit derived from an organic diisocyanate compound, in addition to the caprolactam-derived repeating unit, and has heat resistance by containing an imide ring. As a result, the cohesive force of the polyamide portion is reduced and the melting point is lowered. This has the advantage that the molding temperature can be lowered, and when used as a resin modifier, the range of kneading conditions can be widened. Further, when the amount of the organic diisocyanate compound is increased, the crystallization temperature is lowered, so that the flowability during injection molding can be improved.

Examples of such an organic diisocyanate compound include hexamethylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate. One of these organic diisocyanate compounds may be used, or two or more thereof may be used in combination. The amount of the organic diisocyanate compound used is desirably not more than 1 mol of the glycol of the component (D). This amount is 1
If the molar ratio is more than twice, it depends on the type of the diisocyanate compound, but it is not preferable because the coloring becomes strong and the melting point becomes too low. More preferably 0.8
The molar amount is not more than twice, but if the amount is not more than 0.01 times, the effect may not be sufficiently exhibited.

Advantageously, the polyamide imide dicarboxylic acid has a number average molecular weight in the range from 500 to 3000. This number average molecular weight is calculated from the charged composition and the amount of recovered caprolactam during polymerization.If the number average molecular weight is less than 500, the cohesive force of the hard domain is reduced, and as a result, the mechanical strength is reduced and 3,000 is obtained. Above this, transparency is lost.

On the other hand, the soft segment in the polyamide-imide elastomer of the present invention has a number average molecular weight of the component (D) of 50.
0 to 4000 polyoxyalkylene glycol and α, ω
At least one selected from dihydroxy hydrocarbons;
It is derived from the species glycol. Examples of the polyoxyalkylene glycol include polyoxytetramethylene glycol, modified polyoxytetramethylene glycol, polyoxypropylene glycol, polyoxyethylene glycol, and copolymerized glycols thereof.

When polyoxytetramethylene glycol is used as the glycol component, if the number average molecular weight exceeds 4,000, the low temperature characteristics will be poor.

In particular, when only polyoxytetramethylene glycol is used as the soft segment, it is preferable to use one having a number average molecular weight of 500 to 3,000 from the viewpoint of low-temperature characteristics. Further, from the viewpoint of low-temperature characteristics, the molecular weight distribution of polyoxytetramethylene glycol ▲ ▼ / ▲ ▼ (▲
▼ is the number average molecular weight obtained from the terminal hydroxyl value, ▲
▼ is an expression And η is the melt viscosity at a temperature of 40 ° C. expressed in poise.) It is preferable to use a material having a sharpness of 1.6 or less.

In the present invention, a modified polyoxytetramethylene glycol can be used instead of the above polyoxytetramethylene glycol. As the modified polyoxytetramethylene glycol, a part of — (CH ₂ ) ₄ —O— of ordinary polyoxytetramethylene glycol is
And those substituted with RO-. Here, R is an alkylene group having 2 to 10 carbon atoms, specifically, an ethylene group, a 1,2-propylene group, a 1,3-propylene group, a 2-methyl-1,3-propylene group, a 2,2 -Dimethyl-1,3-propylene, pentamethylene, hexamethylene and the like are preferred. The amount of modification is not particularly limited, but is usually selected in the range of 3 to 50% by weight. The amount of modification and the type of the alkylene group are appropriately selected depending on the required characteristics of the elastomer, such as low-temperature characteristics, heat resistance, weather resistance, and the like.

The modified polyoxytetramethylene glycol can be produced, for example, by copolymerization of tetrahydrofuran and diol using a heteropolyacid as a catalyst, or copolymerization of diol or a cyclic ether which is a condensate of diol with butanediol.

When imparting hydrophilicity to the elastomer of the present invention,
Polyoxyethylene glycol can be used, and depending on its hydrophilicity, it can be used alone or in combination with polyoxymethylene glycol. Polyoxyethylene glycol is easily crystallized even when incorporated into a block copolymer when it has a high molecular weight, and rubber elasticity at low temperatures is difficult to develop, so when used alone, the number average molecular weight is 500 to 2500. It is preferred to use

As the α, ω-dihydroxy hydrocarbon, for example, polyolefin glycol or hydrogenated polybutadiene glycol obtained by polymerizing olefin or butadiene to form a hydroxyl group at the terminal and hydrogenating the double bond can be used. These hydrocarbons have a number average molecular weight of 500-4
Must be in the range of 000. If the number average molecular weight is less than 500, the melting point of the obtained elastomer will be low, or there will be problems such as not having excellent physical properties. Is difficult to obtain.

The glycol of the component (D) used in the present invention may be used alone or as a mixture of two or more.
The type, molecular weight, and ratio of the glycol to be used are appropriately selected in consideration of various properties such as low-temperature properties, weather resistance, and oil resistance of the elastomer.

In the present invention, the component (B), the component (C) and the component (D) are represented by the following formula: as well as It is necessary to use them at a ratio that satisfies the relationship of
When the value of b / (c + d) deviates from the above range, the polyamideimide elastomer does not have a high molecular weight and tends to have a low strength.

Further, the component (D) is preferably used so that the content of the soft segment in the polyamide-imide elastomer is 30 to 85% by weight, and if this amount is less than 30% by weight, the polyamide-imide elastomer becomes flexible or transparent. The properties are impaired, and if it exceeds 85% by weight, the strength tends to decrease. The hardness of the polyamide-imide elastomer can be controlled mainly by the content of the polyamide-imide component. In particular, by setting the polyamideimide component in the elastomer to 15 to 45% by weight, a soft and tough elastomer having a hardness in the vulcanized rubber region of a Shore hardness of 60A to 40D can be obtained.

In the present invention, two methods are used. One of the methods is that the caprolactam of the component (A), the aromatic polycarboxylic acid or the acid anhydride thereof of the component (B), and the organic diisocyanate compound of the component (C) are prepared in advance. Is subjected to a melt reaction at a temperature in the range of 200 to 300 ° C. to produce a polyamide-imide oligomer,
In this method, the oligomer and the glycol (D) are dehydrated and condensed in the presence of caprolactam.

In this method, the polyamide-imide elastomer derived from caprolactam lacks compatibility with the glycol of component (D), and cannot be homogeneously polymerized by phase separation even in a molten state. Caprolactam acts as a compatibilizer, so that both are uniformly melted, enabling homogeneous polymerization. At this time, the amount of caprolactam used is at least 0.
Requires 2 times the weight, the composition and molecular weight of the oligomer,
It is appropriately selected according to the type and molecular weight of the glycol (D). If the molecular weight of the oligomer and the glycol of the component (D) is too large, it is difficult to achieve compatibility, so that it is necessary to increase the amount of caprolactam used. Further, in this reaction, a part of caprolactam further reacts with the polyamide-imide oligomer part, and this must be considered when designing the polymer composition. The reaction between the polyamideimide oligomer and the glycol (D) is carried out at a temperature in the range of 200 to 300 ° C. while removing water produced by the reaction outside the system by, for example, introducing an inert gas or reducing the pressure. Will be After completion of the reaction, unreacted caprolactam was distilled off under reduced pressure.
If necessary, 200-300 ° C. under reduced pressure, preferably 23
By post-polymerizing at a temperature of 0 to 280 ° C, higher polymerization can be achieved.

If the reaction temperature in this polymerization reaction is less than 200 ° C., the polymerization rate is slow and not practical, and if it exceeds 300 ° C., thermal deterioration occurs, which is not preferable.

Another method according to the present invention is a method for preparing a polycarboxylic acid or an acid anhydride thereof of the above-mentioned component (B) and (D)
After reacting with the glycol component to produce a polyester oligomer, the oligomer is added to the (A)
In this method, the caprolactam component and the organic diisocyanate compound (C) are added and polymerized.

In the esterification reaction between the component (B) and the component (D), water is generated, and depending on conditions, about 0.1 to 0.8% by weight of water remains in the generated polyester oligomer. When caprolactam of component (A) and organic diisocyanate compound of component (C) are added to such oligomer and heated, the reaction mechanism is not clear, but ring-opening polymerization of caprolactam due to the carboxyl group of polyester oligomer, organic diisocyanate Amidation with a compound, transesterification, amidation of an ester bond with an aminocarboxylic acid generated from caprolactam and water, imidation at a polycarboxylic acid portion, and the like occur, and the same polyamideimide elastomer as that described above is obtained. This reaction is performed at a temperature in the range of 200 to 300 ° C. while removing generated water out of the system. According to such a method, the polymerization time after adding caprolactam is shortened, and coloring of the polymer can be reduced. Also in the above method, the heating time after adding the glycol is shortened, and coloring can be reduced. To remove the water generated by the reaction out of the system,
An inert gas may be introduced, or the pressure may be reduced.

In this method also, after the completion of the polymerization reaction in the same manner as in the above method, the reaction mixture is, if necessary,
By post-polymerizing at a temperature of from about 300 ° C., preferably from 230 to 280 ° C., higher polymerization can be achieved.

According to the method of the present invention, the degree of polymerization of the polyamideimide elastomer can be arbitrarily changed as necessary, but the relative viscosity measured at 30 ° C. at 0.5% by weight / metacresol volume% is 1.5 or more. Is preferred.
If it is lower than 1.5, disadvantages such as insufficient mechanical properties may occur. More preferably, it is 1.6 or more.

In this reaction method, an esterification catalyst can be used as a polymerization accelerator. Examples of the catalyst include phosphoric acid, tetrabutyl orthotitanate, tetraalkyl orthotitanate such as tetraisopropyl orthotitanate, and tetrabutoxyzirconium. And tin-based catalysts such as tetraalkoxyzirconium, dibutyltin oxide and dibutyltin laurate, manganese-based catalysts such as manganese acetate, and lead-based catalysts such as lead acetate. The catalyst may be added at the beginning of the polymerization or at the middle of the polymerization. When a catalyst which is easily hydrolyzed by water, such as tetraalkyl orthotitanate or tetraalkoxyzirconium, is used, it is advantageous to add the catalyst at the middle stage of the polymerization in which most of the water in the yarn is removed.

Further, in order to enhance the thermal stability of the obtained polyamideimide elastomer, various kinds of stabilizers such as heat aging inhibitors and antioxidants can be used. It may be added or may be added after polymerization. As the heat stabilizer, for example, N, N '
-Hexamethylene-bis (3,5-tert-butyl-4-hydroxycinnamic acid amide), 4,4'-bis (2,6-di-tert-butylphenol), 2,2'-methylenebis (4-ethyl -6-tert-butylphenol), various hindered phenols, N, N'-bis (β-naphthyl) -p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, poly (2,2, Aromatic amines such as 4-trimethyl-1,2-dihydroquinoline); copper salts such as copper chloride and copper iodide; and sulfur compounds and phosphorus compounds such as dilauryl thiodipropionate. Further, the polyamideimide elastomer obtained in the present invention may optionally contain an ultraviolet absorber, an antistatic agent, a coloring agent, a filler, a hydrolysis resistance improver, and the like.

Effect of the Invention The polyamide-imide elastomer of the present invention has excellent flexibility, transparency and mechanical strength, as well as excellent heat resistance and resin modifying properties, and is required to have transparency, unlike the conventional one. For example, it is suitably used for materials such as hoses, tubes, and sheets, plastic modifiers, and photoresist base polymers.

Examples Next, the present invention will be described in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

In addition, each physical property of the elastomer was obtained as follows.

(1) Shore hardness It was measured using a durometer according to ASTM D-2240.

(2) Tensile breaking strength The elastomer was formed into a sheet having a thickness of 1 mm by a hot press, a dumbbell-shaped sample was punched out in accordance with JIS K 6301, and the strength was measured with a tensile strength tester (Instron).

(3) Relative viscosity The relative viscosity was measured in metacresol at 30 ° C. and 0.5% by weight / volume.

(4) Thermal decomposition temperature The weight loss temperature was measured using a differential thermobalance, and the temperature was raised at a rate of 10 ° C / min.
Was measured.

(5) Melting point and crystallization temperature Using a differential thermobalance, the melting point was measured at a rate of temperature rise of 10 ° C / min, and the temperature was lowered at 5 ° C / min to determine the crystallization temperature.

(6) Haze Number Using a 1 mm thick sheet, the haze was measured by a haze meter according to a method in accordance with ASTM D 1003-61.

Example 1 500 ml equipped with a stirrer, a nitrogen inlet, and a distillation tube
In a separable flask, 23.1 g of trimellitic acid, 2.5 g of diphenylmethane diisocyanate 104 g of caprolactam.
9 g of pentaerythrityl-tetrakis [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate] (antioxidant, trade name Irganox 1010) 0.3 g
The mixture was replaced with nitrogen, and reacted at 260 ° C. for 4 hours to obtain a polyamideimide oligomer.

In a similar apparatus, 44 g of the oligomer, caprolactam 3
2.7 g and 50.0 g of polyoxyethylene glycol having a number average molecular weight of 1490 were charged, and while flowing nitrogen at 50 ml / min, 260
After reacting at 2 ° C. for 2 hours, 27.8 g of unreacted caprolactam was distilled off under reduced pressure. Next, 0.2 g of tetrapropyl orthotitanate was added thereto, and the mixture was added at 260 ° C. and 1 Torr for 2 hours.
Polymerization was performed for a time to obtain a pale yellow transparent polymer having a relative viscosity of 1.95.

This polymer shows imide group absorption in the IR spectrum, and a polyoxyethylene glycol segment of 50% by weight.
A polyamide-imide elastomer containing
370 kg / cm ² and elongation 750%.

Example 2 500 ml equipped with a stirrer, a nitrogen inlet, and a distillation tube
In a separable flask, 78.0 g of polyoxyethylene glycol having a number average molecular weight of 1490 and 11.1 g of trimellitic anhydride
And an antioxidant N, N'-hexamethylene-bis (3,5-
Di-t-butyl-4-hydroxycinnamic acid amide) (trade name Irganox 1098) was charged together with 0.3 g, and nitrogen was added to the mixture.
Melt at 150 ° C while flowing at ml / min.
Reacted for hours. A colorless, transparent, viscous liquid was obtained. From this IR spectrum, it was confirmed that the acid anhydride group had disappeared and an ester bond had been formed.

Next, caprolactam 91.
7 g and 1.3 g of diphenylmethane diisocyanate were added, and 26
After the temperature was raised to 0 ° C. and the reaction was carried out at this temperature for 4 hours, unreacted caprolactam was removed under reduced pressure, and then 0.3 g of tetrabutyl orthotitanate was added thereto.
Polymerization at 1 Torr caused a rapid rise in viscosity, yielding a polymer with a relative viscosity of 2.1 in 45 minutes.

This polymer is light yellow transparent and has IR spectrum and
NMR analysis confirmed that it was the same polyamideimide elastomer as in Example 1. The content of the polyoxyethylene glycol segment was 56% by weight, the strength was 300 kg / cm ² ,
The elongation was 950% and the haze number was 45%.

Examples 3 and 4 In Example 1, the molar ratio of diphenylmethane diisocyanate / polyoxyethylene glycol was changed from 0.1 to 0.3.
Polymerization was carried out in the same manner as in Example 1 except that (Example 3) and 0.5 (Example 4) were changed to obtain a polyamideimide elastomer having a polyoxyethylene glycol segment content of 50% by weight. Table 1 shows the melting points, crystallization temperatures and thermal decomposition temperatures of these elastomers.

These elastomers were all transparent, and the haze number of Example 3 was 45% and the haze number of Example 4 was 47%.

Examples 5 and 6 In Example 1, instead of polyoxyethylene glycol, a polyoxytetramethylene glycol having a number average molecular weight of 1980 (▼ / オ レ フ ィ ン = 1.45) or a saturated polyolefin glycol having a number average molecular weight of 2200 [Mitsubishi Kasei Co., Ltd., trade name: Polyether HA]
A polyamideimide elastomer was obtained in the same manner as in Example 1 except that trimellitic anhydride was used instead of trimellitic acid. The physical properties are shown in Table 2. All the elastomers were pale yellow and transparent.

Example 7 The procedure of Example 5 was repeated, except that pyromellitic anhydride was used instead of trimellitic anhydride, hexamethylene diisocyanate was used as the isocyanate, and tetrabutoxyzirconium was used as the catalyst. Oxytetramethylene glycol segment 56
A polyamide-imide elastomer containing 55% by weight and having a haze number of 55%, a light yellowish brown color, a relative viscosity of 2.0, a tensile strength of 320 kg / cm ² and an elongation of 930% was obtained. Its melting point is 205 ° C,
The thermal decomposition onset temperature was 327 ° C.

Comparative Example 260 ml of caprolactam, 33.2 g of adipic acid and 6 g of water were charged in place of the reflux condenser in the distillation tube of the apparatus of Example 1, and 260 g of water was added.
C. for 6 hours to produce folicapamide having a terminal carboxyl group. This is the average molecular weight from acid value measurement.
883.

The apparatus of Example 1 was charged with 40 g of the polyamide, 97.4 g of polyoxytetramethylene glycol of Example 5, 0.3 g of an antioxidant (Irganox 1098) and 0.2 g of tetrabutyl orthotitanate. 2 to 3 torr at 1 to 3 torr, 260 ° C
When polymerization was carried out for 8 hours, coarse phase separation occurred during the polymerization, and the melt became milky white, milky white until the end of the polymerization, and the obtained elastomer was opaque (hazy number: 90% or more). This elastomer contained 70% by weight of polyoxytetramethylene glycol segments and was brittle. Also, relative viscosity 1.45, melting point 95-120
° C, the thermal decomposition onset temperature was 308 ° C, and the tensile strength was 40 kg / cm ² .

Claims (2)

(57) [Claims] 1. A caprolactam, (B) a trivalent or tetravalent aromatic polycarboxylic acid capable of forming at least one imide ring or an acid anhydride thereof, (C) an organic diisocyanate compound and (D) At least one glycol selected from a polyoxyalkylene glycol having a number average molecular weight of 500 to 4000 and an α, ω-dihydroxy hydrocarbon, as well as [However, b, c and d are each a component (B),
(Representing the number of moles of the components (C) and (D))] to produce the polyamide-imide elastomer under the conditions satisfying the relationship of (A), (B) and (C). B) reacting the oligomer with the component to form a polyamide-imide oligomer. The oligomer is mixed with the component (D) in the presence of caprolactam at least 0.2% by weight of the oligomer while removing water produced by the reaction. Polymerized at a temperature of 200-300 ° C,
Next, unreacted caprolactam is removed, and post-polymerization is further carried out under reduced pressure at a temperature of 200 to 300 ° C., if necessary, to produce a polyamide-imide elastomer. 2. A caprolactam, (B) a trivalent or tetravalent aromatic polycarboxylic acid capable of forming at least one imide ring or an acid anhydride thereof, (C) an organic diisocyanate compound and (D) At least one glycol selected from a polyoxyalkylene glycol having a number average molecular weight of 500 to 4000 and an α, ω-dihydroxy hydrocarbon, as well as [However, b, c and d are each a component (B),
(C) represents the number of moles of the component (C) and the component (D).] The components (B) and (D) are reacted in advance to produce the polyamideimide elastomer under the condition that the following relationship is satisfied. After producing a polyester oligomer, the components (A) and (C) are added to the oligomer, and while the water generated by the reaction is removed, polymerization is carried out at a temperature of 200 to 300 ° C. A method for producing a polyamide-imide elastomer, further comprising performing post-polymerization under reduced pressure at a temperature of 200 to 300 ° C.