JPS61247732A - Production of polyamide elastomer - Google Patents

Abstract

PURPOSE:To obtain a polyamide elastomer excellent in mechanical properties and transparency, by polymerizing caprolactam with polytetramethylene glycol and a dicarboxylic acid while keeping the water content of the polymerization mixture within a specified range. CONSTITUTION:In producing a polyamide elastomer by polymerizing caprolactam (A) with polytetarmethylene glycol of an average MW of 800-5,000 or a modified polytetramethylene glycol (B) derived by replacing part of the groups of the formula in polytetramethylene glycol with groups of another structural formula derived from a diol component and having an average MW of 800-5,000 and a dicarboxylic acid (C) selected from among an aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid and an aromatic dicarboxylic acid, said polymerization is performed at 150-300 deg.C and a water content in the polymerization mixture kept at 0.1-1wt%, unreacted caprolactam is removed from the mixture and the post polymerization is performed to obtain the purpose elastomer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing polyamide elastomers. More specifically, polycabramide was used as the hard segment, and polytetramethylene glycol was used as the soft segment. This invention relates to a method for producing a polyether ester amide type polyamide elastomer having excellent mechanical properties and transparency.

[Prior Art] A method for producing a polyether ester amide type polyamide elastomer in which polyamide is used as a hard segment, polyether is used as a soft segment, and both are connected by an ester bond is as follows: polyamide having carboxyl groups at both ends and polytetramethylene. A method for rapid dehydration condensation of glycol using a Ti or Zr catalyst
B-45419 and Japanese Patent Publication No. 58-11459), a method of polymerizing by further adding water to a mixture of an aminocarboxylic acid having 10 or more carbon atoms or a lactam, polytetramethylene glycol, and dicarboxylic acid (Japanese Patent Publication No. 57-24
808), or a method of reacting ε-ashitsukaproic acid, polytetramethylene glycol, and dicarboxylic acid (Japanese Patent Application Laid-Open No. 58-21095).

It is also known that the reaction between caprolactam and a polyester obtained from polyether diol and dicarboxylic acid is known (West German Published Patent No. 2135770). A polyetheresteramide type polyamide elastomer is not yet known.

[Problems to be Solved by the Invention] Polyamide and polytetramethylene glycol have poor compatibility, and polycapramide in particular has poor compatibility with polytetramethylene glycol.Moreover, as the molecular weight of polytetramethylene glycol increases, polycapramide The compatibility with is poor.

The method of Japanese Patent Publication No. 5B-45418 and No. 58-11459 uses a special catalyst to quickly perform dehydration condensation of carboxyl group-terminated polyamide and polytetramethylene glycol, and also uses nylon-11 and nylon-12. etc. have relatively good compatibility with polytetramethylene glycol, so that homogeneous polymerization can be carried out, but when polycapramide is used, coarse phase separation occurs, making homogeneous polymerization difficult.

In Japanese Patent Publication No. 57-24808, polymerization is carried out by adding 2 to 30 weight percent of water to a polyamide-forming component to a mixture of a lactam having 10 or more carbon atoms, an aminocarboxylic acid, polytetramethylene glycol, and a dicarboxylic acid. It is. In this polymerization system, Dip Ang
ewandte Makromolekulare C
Bemie 74 (1978) 49, lactam polymerization occurs preferentially, while esterification hardly occurs, resulting in a polymerization system that is primarily a mixture of carboxyl-terminated polyamide and polytetramethylene glycol. Then, both are subjected to dehydration condensation to form a polyether ester amide. When caprolactam is applied to this system, carboxyl group-terminated polycapramide is preferentially produced as described above, but this has poor compatibility with polytetramethylene glycol and causes coarse phase separation in the polymerization system, causing polymerization to proceed. However, phase separation is not resolved, and only a milky white polyamide elastomer with poor mechanical properties is obtained.

Furthermore, JP-A-58-21095 discloses a method in which a mixture of ε-aminocaproic acid, polytetramethylene glycol and dicarboxylic acid is heated and melted and then polymerized.
Aminocaproic acid polymerizes quickly and generates a large amount of water during polymerization. Even in the powder process, esterification hardly occurs during the homogenization step of heating and melting or during the initial stage of polymerization, and polyamide is preferentially produced.As the polyamide produced is difficult to be compatible with polytetramethylene glycol, coarse phase separation occurs, resulting in transparent polyamide elastomer cannot be obtained.

Furthermore, West German Published Patent Application No. 2135770 discloses a method in which a polyether diol and a dicarboxylic acid are dehydrated and condensed to synthesize a polyether polyester having carboxyl group terminals in advance, and caprolactam is polymerized thereto.

The result is a brittle polymer that is unlikely to become a strong elastomer.

Although the conditions for producing these known polyetheresteramide type polyamide elastomers are different, the essence of the reaction is that the polymerized carboxyl group-terminated polyamide and polytetramethylene are reacted in advance or preferentially at the reaction site. It condenses glycol. The other manufacturing method involves reacting a dicarboxylic acid and a polyether diol to form a polyester, and then reacting this polyester with a ragtam. In any case, a polymerization method is used in which esterification and polyamidation are distinguished.

Now, caprolactam, which is industrially easily available and inexpensive, is used as the polyamide component. Polyamide elastomers that are transparent and have excellent mechanical properties are considered to be extremely useful industrially, but as mentioned above, there is still no satisfactory manufacturing method.

[Means for solving the problem] Therefore, the present inventors used caprolactam as a polyamide component, and in order to synthesize a homogeneous elastomer with excellent mechanical properties, we investigated the compatibilization of the polyamide component and polyether component during polymerization. After extensive research, we found that when polymerizing a mixture of caprolactam, polytetramethylene glycol, and dicarboxylic acid, it was possible to polymerize without adding water, which is a polymerization accelerator for lactam, and to remove the water produced by esterification. When water in a product is polymerized in a range of 0.1 to 1% by weight, caprolactam polymerization occurs simultaneously with esterification, and under conditions where esterification occurs, caprolactam polymerization is significantly accelerated, resulting in esterification and caprolactam opening. It was found that ring polymerization proceeds in parallel. In addition, perhaps because esterification and caprolactam polymerization proceed simultaneously, the polymerization system does not undergo coarse phase separation, and the polymerization proceeds while maintaining a uniform and transparent molten state, resulting in a transparent polyether ester with excellent mechanical strength. It was discovered that an amide type polyamide elastomer can be obtained, leading to the present invention.

That is, the present invention provides A) caprolactam B) polytetramethylene glycol having an average molecular weight of 800 to 5,000, or 4GH2) 40- of polytetramethylene glycol having an average molecular weight of 800 to 5,000, to other compounds derived from diol components. A polyamide elastomer is produced by polymerizing a modified polytetramethylene glycol partially replaced with that shown by the structural formula, and C) a dicarboxylic acid selected from aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids. 150~
Polymerization at 300°C while maintaining the water content in the polymer at 0.1 to 1% by weight, followed by removal of unreacted caprolactam, or post-polymerization at 200 to 300°C after removing unreacted caprolactam. The present invention relates to a method for producing a transparent polyamide elastomer characterized by:

In producing the polyamide elastomer of the present invention, there is no particular restriction on the amount of caprolactam used, but in order to obtain an elastomer that is transparent and has strong physical properties, it is preferably 10 to 80% by weight, preferably 10 to 70% by weight, and more preferably 10 to 70% by weight. is 20
Preferably, it is used in an amount of 60% by weight.

Furthermore, the amount of caprolactam to be used is selected depending on the hardness or other physical properties of the intended elastomer or the molecular weight of the soft segment used.

Polytetramethylene glycol has an average molecular weight of 800-5
000 can be used, and if the average molecular weight of polytetramethylene glycol is less than 800, depending on the composition,
This is undesirable because the melting point of the elastomer will be low and it will not have sufficient physical properties, and if the molecular weight is greater than 5000, there will be fewer reaction points.
This is not preferable because it becomes difficult to maintain a balance between esterification and ring-opening polymerization of caprolactam, making it difficult to control the polymerization system.

Consists of modified polytetramethylene glycol (CH2
Structures other than h〇- are not limited to the following, but are diols or those whose structure is the same as those derived from diols (e.g., cyclic ethers), which are exemplified as diols. Then, ■ alkylene glycols, such as ethylene glycol, propylene glycol, neopentyl glycol, 1,6 hexanediol, ■ diol containing an oxygen atom in the main chain,
For example, it is a condensed ether of the above-mentioned alkylene glycol. Mono- or polyether glycols, ■ Diols containing sulfur in the main chain, such as thioether diols, specifically thiogetanol, polythiogenol oligomers, ■ Diols containing nitrogen in the main chain, such as tertiary amines. Examples include diols such as N-butylgetanolamine and N-butyldibrobanolamine. The modified polytetramethylene glycol referred to in the present invention is obtained by condensation polymerization or ring-opening addition polymerization of the above-mentioned diols, or cyclic ethers and butanediol that are condensates of diols, or polytetramethylene glycol, or cyclic ethers that are condensates thereof. Manufactured by etc.

These modified polytetramethylene glycols serve as soft segments of the elastomer, and their composition is selected depending on the required performance of the elastomer, such as low-temperature properties, heat resistance, or weather resistance.

The dicarboxylic acid used in this reaction is preferably used in such a manner that C00H10H = 1.1 to 0.9 relative to polytetramethylene glycol, and the amount of dicarboxylic acid is at least greater than the above-mentioned range. This is not preferable because the molecular weight of the elastomer does not become large and mechanical properties deteriorate.

Examples of such dicarboxylic acids include aliphatic dicarboxylic acids such as adipic acid, sepatic acid, azelaic acid, and dodecanedioic acid; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid and decalin dicarboxylic acid; isophthalic acid, terephthalic acid, and naphthalene dicarboxylic acid; Aromatic dicarboxylic acids and the like are used.

In this reaction, caprolactam, polytetramethylene glycol, and dicarboxylic acid are melt-polycondensed at 150 to 300°C, more preferably 180 to 280°C, but the reaction temperature can also be raised stepwise. In addition, some caprolactam remains unreacted, but this can be distilled off under reduced pressure, and in order to obtain a higher polymer, after caprolactam is distilled off, the caprolactam is heated under reduced pressure at 200 to 300°C, more preferably at 230°C. It is also possible to postpolymerize at ~280°C. If the polymerization temperature is lower than 150°C, the polymerization rate will be extremely slow, which is undesirable, and if it exceeds 300°C, thermal deterioration will occur, which is undesirable.

Homogeneous polymerization is necessary to obtain a transparent and tough elastomer like the one of the present invention, and for this purpose, it is important that the esterification reaction and the caprolactam polymerization proceed simultaneously during the polymerization. I found out. If caprolactam is preferentially polymerized or esterified preferentially, coarse phase separation occurs and transparency is lost, and only an elastomer with low strength is produced. The amount of water in the polymerization system is deeply involved in causing the esterification reaction and the polymerization of caprolactam to occur simultaneously and controlling the rate of each reaction. If polymerization is carried out at 1% by weight, a transparent and tough elastomer can be obtained.

In this case, the ratio between the caprolactam conversion rate and the esterification rate depends on the molecular weight of the polytetramethylene glycol used and the amount of caprolactam, but the ratio is approximately 0.2 to 3. in range. If the amount of water in the polymerization system is greater than 1% by weight, caprolactam polymerization takes priority and coarse phase separation occurs, which is not preferable. On the other hand, if the amount of water is less than 0.1% by weight, esterification takes priority, caprolactam does not react, and an elastomer with the intended composition cannot be obtained. is 0.
It is selected in a range of 1 to 1 weight percent depending on the target polymer. Depending on the case, a method may be adopted in which the amount of water in the polymerization system is decreased as the polymerization progresses. The amount of water can be controlled by polymerization conditions such as polymerization temperature, insoluble gas flow rate or degree of vacuum, and reactor structure.

In this reaction, esterification catalysts can be used as polymerization promoters, such as phosphoric acid, tetraalkyl titanates such as tetrabutyl titanate, tin-based catalysts such as dibutyltin oxide and dibutyltin laurate, manganese-based catalysts such as manganese acetate, etc. A lead-based catalyst such as lead acetate is preferably used. The catalyst may be added at the initial stage of polymerization or at the middle stage of polymerization. In addition, in order to increase the thermal stability of the polyamide elastomer obtained, stabilizers such as various heat-resistant anti-aging agents and antioxidants can be used. You may. It can also be added after polymerization and before molding. Examples of heat-resistant stabilizers include N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxycinnamic acid amide) and 4,4'-bis(2,6-di-tert-butylphenol). , 2.2'-methylenebis(4-ethyl-
various hindered phenols such as (6-tert-butylphenol), N,N'-bis(β-naphthyl)-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, poly(2,2, 4-) Riftyl-1,2
- aromatic amines such as dihydroquinoline), copper chloride,
Examples include copper salts such as copper iodide, sulfur compounds such as dilaurylthiodipropionate, and phosphorus compounds. Furthermore, the polyamide elastomer of the present invention can optionally contain an ultraviolet absorber, an antistatic agent, a coloring agent, a filler, a hydrolysis resistance improver, and the like.

[Effects of the Invention] The polyether ester amide type polyamide elastomer obtained by the present invention is an elastomer that is transparent and has strong physical properties, unlike those obtained by conventional techniques, and is suitable for fields where transparency is required. For example, it is particularly advantageously used in the fields of hoses, tubes, sheets, etc., and has high industrial value.

[Example] The present invention will be explained below with reference to Examples. In the examples, the relative viscosity is 0.5 t/v at 30°C in metacresol.
oj? Measured in %. The polymer is heat-pressed to a wall thickness of 1~
2+am sheet and a tensile test was conducted at 23°C.Example 1 500+s with a stirrer, nitrogen inlet and distillation tube attached
151 g of caprolactam and 111 g of polytetramethylene glycol (@average molecular weight 11
10) and adipic acid 15. Elg is N, N'-hexamethylene-bis(3,5-di-t-butyl-4-hydroxycinnamic acid amide) (trade name "Irganox" 109)
8: Prepare with 0.15 g of antioxidant) and 90.15 g of phosphorus, flow nitrogen at 20 ml/win, and
Polymerization was carried out at 240°C for 2 hours, at 260°C for 8 hours. Next, the pressure was gradually reduced at the same temperature, and unreacted caprolactam was distilled out of the system at 1 torr for 30 minutes, to obtain a pale yellow, bright elastomer. This elastomer had a polytetramethylene glycol content of 44% by weight, a melting point of 197-208°C, a relative viscosity of 1.88, and a tensile strength and elongation of 360 kg/cm and 2.750%, respectively. The rate of decrease in acid value corresponding to the conversion rate and esterification rate of caprolactam during polymerization was 37% and 38% at 2 hours, 57% and 65% at 4 hours, and 78% and 92 at 122 hours, respectively. %, and the amount of water in the polymerization system analyzed over time was o, e, 0.8, 0.5, and 0.4 weight percent at 1, 2, and 4.8 hours after the start of polymerization, respectively. .

Example 2 Raw materials were charged in the same manner as in Example 1, and polymerized at 260°C for 8 hours. Polymerization was then continued under reduced pressure for 2 hours at the same temperature while recovering unreacted caprolactam to obtain a pale yellow transparent elastomer. . The concentration of water in the polymerized product was 0.7 and 0.1 hours, respectively, at 1 hour, 2 hours, 4 hours, and 6 hours after the start of polymerization. [
! , 0.5, 0.4 weight percent, and the solution was always homogeneous and transparent during the polymerization. Moreover, the esterification rate and the conversion rate of caprolactam were 82% at 1, 2, and 4.6 hours, respectively.

57% Near 4%, 65%; 78%, 73%: 84%, 7
It was 5%. This elastomer has a polytetramethylene glycol content of 44% by weight, a melting point of 201-210'O1, a relative viscosity of 1.75, and a tensile strength of 52
0kg/cm2. The elongation was 750%.

Comparative Example 1 The same raw materials as in Example 1 were charged into an autoclave with an internal volume of 500+JL, and 6.8 g of water was added, and the temperature was heated to 270°C.
When heated to , the pressure inside the autoclave is 8 kg/cm.
It showed a gauge pressure of 2. After reacting at this temperature for 7 hours, the autoclave was rapidly cooled and the contents were taken out.
The upper layer is a white solid, which according to the infrared absorption spectrum is polycapramide with terminal carpoxyl groups.
The lower layer was liquid and was mainly composed of polytetramethylene glycol, with some caprolactam dissolved therein.

The contents were placed in the same apparatus as in Example 1, heated to 260°C to distill off water, and polymerized at the same temperature for 8 hours. The polymer was milky white and had undergone coarse phase separation, and remained milky even as the polymerization proceeded. After polymerization, unreacted caprolactam was distilled off under reduced pressure at the same temperature for 30 minutes to obtain a milky white opaque elastomer. This product contains 40% by weight of polytetramethylene glycol and has a melting point of 2.
02-207℃, relative viscosity 1.31, tensile strength 115k
The elongation was 100% in g/cm2, and it was brittle.

Comparative Example 2 The distillation tube of the apparatus of Example 1 was replaced with a condenser, and 253 g of caprolactam, 48.8 g of adipic acid, and 4 g of water were charged, and the mixture was reacted at 280'O for 6 hours to synthesize polycoupler [-'' with a terminal carboxyl group. This product had an average molecular weight of 1106 based on acid value measurement. 100 g of the above polyamide, 100 g of polytetramethylene glycol with a number average molecular weight of 1110, and 0.8 g of tetrabutyl titanate were charged into the apparatus of Example 1, and heated at 260°C. During the polymerization, which was carried out for 4 hours at 1 torr, the polymer exhibited a milky white color, and a milky opaque elastomer was obtained.This material had a relative viscosity of 1
．． 72, but it was brittle with a tensile strength of 100 kg/cm2 and an elongation of 300%.

Comparative Example 3 Prepared in the same manner as in Example 1 except that 172 g of ε-aminocaproic acid was used instead of caprolactam and 0.3 g of tetrabutyl titanate was used instead of phosphoric acid.
The reaction was carried out at 0°C for 30 minutes. Immediately after melting, the solution was homogeneous and transparent. Approximately 18 g of water was distilled out in 30 minutes, and the solution became milky white. From its infrared absorption spectrum, polyamide with terminal carboxyl groups was produced. It was found that polytetramethylene glycol was hardly reacted because almost no ester bonds were observed. or,
During this period, the amount of water in the reaction solution was 2.5 to 3.0% by weight. Subsequently, the temperature was raised to 260° C., and the pressure was gradually reduced to 1 torr for polymerization for 4 hours to obtain a milky white opaque elastomer. This product has a relative viscosity of 1.
No. 35, it was brittle with a tensile strength of 90 kg/cm2 and an elongation of 20 to 30%.

Comparative Example 4 In the same apparatus as in Example 1, 114.9 g of polytetramethylene glycol with an average molecular weight of 1500 and 11.9 g of adipic acid were added.
8 g was charged and reacted for 12 hours while flowing nitrogen at a rate of 20w1/win to obtain a polyether ester. 124 g of caprolactam was added thereto, and the mixture was reacted at 245° C. for 12 hours, and then the unreacted caprolactam was distilled off under reduced pressure at the same temperature to obtain a polymer. This polymer contains 74% by weight of polytetramethylene glycol,
It was brittle with a tensile strength of 50 kg/c+s2 and an elongation of 100%.

Comparative Example 5 The same raw materials as in Example 1 were charged into an autoclave with an internal volume of 500 mM, and then nitrogen was charged at 2 kg/cm2 and heated to 260°C, making sure that the water produced did not come out of the system. Polymerization was carried out for 8 hours. The obtained polymer was milky white, and the amount of water in the polymer was 1.1% by weight. This polymer was charged into the same apparatus as in Example 1 and then polymerized for 8 hours at 260° C. under reduced pressure, but the milky white color did not disappear and the obtained polymer was hard and brittle.

Example 3 93 g of caprolactam and 111 polytetramethylene glycol having a number average molecular weight of 1110 were placed in the same apparatus as in Example 1.
g and 113.8 g of terephthalic acid, 0.1 g of phosphoric acid, “
"Irganox" 10980.1g and polymerized under the same conditions as in Example 1 to produce a transparent polyamide elastomer with a polytetramethylene glycol content of 53% by weight, a relative viscosity of 1.71, a tensile strength of 300kg/am2, and an elongation of 750%. Obtained.

Example 4 311 g of caprolactam and 167 polytetramethylene glycol with a number average molecular weight of 1110 were placed in the same apparatus as in Example 1.
21.9 g of adipic acid, and 10980.3 g of "Irganox" were prepared in the same manner as in Example 1.
The reaction was carried out at 20°C for 2 hours, at 240°C for 2 hours, and at 260°C for 6 hours. Water during polymerization was 0.8-0.4%. Then tetrabutyl titanate) 0.5g and N,N
'-bis(β-naphthyl)-p-phenylenediamine (
Heat-resistant anti-aging agent: Product name “Tsukurak White”) 2
．． 5 g was added, unreacted caprolactam was distilled off under reduced pressure, and polymerization was further carried out at 260° C. and 1 Torr for 3 hours. Polytetramethylene glycol content is 40 weight percent, relative viscosity 1.82, tensile strength 670 kg/cm2. A pale yellow transparent elastomer with an elongation of 600% was obtained. or,
When this product was subjected to a heat resistance test by heating at 120° C. in a gear oven, the tensile strength retention rate was 85% or more after 200 hours.

Example 5 In the same apparatus as in Example 1, 70.3 g of caprolactam and 17 polytetramethylene glycol with a number average molecular weight of 3450 were added.
2.5g, adipic acid 7.3g, phosphoric acid 0.3g and “
10,980.3 g of "1 Irganox" were charged, reacted in the same manner as in Example 1, and polymerized for 9 hours. Unreacted caprolactam was distilled off under reduced pressure to obtain a polytetramethylene glycol content of 84%, a melting point of 155 to 185 °C, A colorless and transparent polyamide elastomer having a relative viscosity of 1°72, a tensile strength of 370 kg/cm2, and an elongation of 920% was obtained.Also, during one polymerization, the water content of the polymer was 0.3 to 0.5% by weight. .

Example 6 In the same apparatus as in Example 1, 105 g of caprolactam and 181 polytetramethylene glycol with a number average molecular weight of 4040 were placed in the same apparatus.
．． 5g, adipine 95.85g, manganese acetate 0.5
g and "Irganox" 1098 (15 g) were charged, and after polymerization for 10 hours in the same manner as in Example 1, unreacted caprolactam was distilled off under reduced pressure to obtain a transparent polyamide elastomer. The methylene glycol content was 80%, the relative viscosity was 1.9, and the tensile strength and elongation were 380 kg/cm2 and 950%, respectively.

Example 7 In the same apparatus as in Example 1, 122 g of caprolactam and 55 g of polytetramethylene glycol with a number average molecular weight of 1100 were added.
．． 8g, decanedicarboxylic acid 12.3g, phosphoric acid 0.
28 and 10980.2 g of "Irganox" were charged, and polymerization was carried out in the same manner as in Example 1 to obtain a pale yellow transparent elastomer.
Contains 5%, relative viscosity! , 6. Strength 270kg/cm2
, the elongation was 700%.

Example 8 In a container equipped with a stirring device and a reflux condenser, 800 g of tetrahydrofuran (THF) and 25 g of ethylene glycol were added.
．． Prepare 5g. Next, phosphotungstic acid (H3PJ20ao
The number of moles of Cx tylene+)-1-l is about 4 times the number of moles of phosphotungstic acid). The temperature was set at 60° C., stirring was continued for 4 hours, and then the mixture was allowed to stand at room temperature to separate into two phases. Unreacted THF was removed from the upper layer by distillation to obtain 128 g of a transparent and viscous polymer.

IH-NMR (400MHz) of the obtained polymer,
As a result of C-NMR (400MHz) measurement, the polymer had ethylene glycol/THF=1/9 (mo
Polyether glycol copolymerized with l ratio)
Ethylene glycol was copolymerized in a laminated manner rather than in a block manner, and as a result of measuring the hydroxyl value, the number average molecular weight was 1500 and the melting point was 14°C.

Into the same apparatus as in Example 1, 120 g of Gaprolactam, 90 g of polytetramethylene glycol copolymerized with ethylene glycol obtained above, and 8.8 g of adipic acid!
J7 @ 0.1g and “Iruka Knox” 1088 at 0.
2 g was charged, and polymerization was carried out in the same manner as in Example 1 for 7 hours. Then, add 0.2g of tetrabutyl titanate and
The pressure was reduced to 60° C., unreacted caprolactam was distilled off, and the mixture was further polymerized for 2 hours at 1 torr to obtain a pale yellow transparent polyamide elastomer.

This product contains 52% copolymerized polytetramethylene glycol.
%, relative viscosity is 1.65, tensile strength is 340kg/
cm2, and the elongation was 750%.

Example 9 Polytetramethylene glycol with a number average molecular weight of 1970 was obtained by copolymerizing neopentyl glycol with THF/neopentyl glycol = 28/1 in the same manner as in Example 8, using neopentyl glycol instead of ethylene glycol. Using this neopentyl glycol-modified polytetramethylene glycol, polymerization was carried out in the same manner as in Example 8, and the resultant product was pale yellow and transparent, the content of the modified polytetramethylene glycol was 53%, and the relative viscosity was 1. 7. Tensile strength 380kg/c+o2. A polyamide elastomer with an elongation of 800% was obtained.

Example 1O In the same manner as in Example 8, using bis-(2-hydroxyethyl)-n-butylamine as the diol, THF
/ bis(2-methoxyethyl)-n-butylamine = 25/1 to synthesize a polyether glycol having a number average molecular weight of 1,700, and synthesize 138 g of the polyether glycol, 85 g of caprolactam, and 11 g of adipic acid.
．． 7g, 0.2g phosphoric acid and “Irganox” 109
8 (L2g) was charged and reacted in the same manner as in Example 1 to obtain a pale yellow transparent polyamide elastomer. This material contained 89% polyether glycol, had a relative viscosity of 1.75, and a tensile strength of 310 kg/ctrr2. , elongation 7
It was 50%.

Example 11 1,000-osyethanol (80111:H2-
Using CH2S-CIhCIhOH), a copolymerized polyether glycol with a number average molecular i of 2000 and TI(F2/thiogentanol=2271) was obtained in the same manner as in Example 10. Contains 68%, relative viscosity 1.6, tensile strength 2'10k
A pale yellow transparent polyamide elastomer with g/cm2 and elongation of 800% was obtained.

Example 12 Polymerization was carried out in the same manner as in Example 2 except that the flow rate of nitrogen was changed to 20011 J/rlIin, and the tensile strength was 310 kg.
A transparent elastomer with an elongation of 600% and an elongation of 600% was obtained. In addition, the amount of water in the polymer is 0.4 to 0.62% during polymerization.
Weight percent. Moreover, the esterification rate and caprolactam conversion rate at 1 and 3.6 hours after the start of polymerization were 55%, 49%; 77%, 81%; 86%, 67%, respectively.

Example 13 Instead of flowing nitrogen, the reaction system was heated for 200 to 250 aya+
) Polymerization was carried out in the same manner as in Example 2 except that the pressure was reduced to 1 g, and the tensile strength was 300 kg/cm2. A transparent elastomer with an elongation of eoo% was obtained. This elastomer contained 45% polytetramethylene glycol, and the amount of water in the polymer was approximately constant at 0.3 to 0.2 weight percent during polymerization. In addition, the changes over time in the esterification rate and caprolactam conversion rate were 54% and 46% at 1 hour, respectively.
%, 74% at 2nd hour, 52%, 88% at 6th hour, 6
There was a 2% tear.

Claims (2)

[Claims] (1) Polyamide elastomer is produced by polymerizing A) caprolactam B) polytetramethylene glycol with an average molecular weight of 800 to 5000, and C) a dicarboxylic acid selected from aliphatic dicarboxylic acid, alicyclic dicarboxylic acid, or aromatic dicarboxylic acid. 150~
Polymerization at 300°C while maintaining the water content in the polymer at 0.1 to 1% by weight, followed by removal of unreacted caprolactam, or post-polymerization at 200 to 300°C after removing unreacted caprolactam. A method for producing a polyamide elastomer having transparency, characterized by: (2) A) Caprolactam B) Modified polytetramethylene having an average molecular weight of 800 to 5000 and partially replacing -(CH_2)-_4 of polytetramethylene glycol with another structural formula derived from a diol component. When producing a polyamide elastomer by polymerizing glycol and C) a dicarboxylic acid selected from aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, or aromatic dicarboxylic acids, the water content in the polymer is reduced to 0 at 150 to 300°C. .1 to 1 weight percent and then removing unreacted caprolactam, or after removing unreacted caprolactam,
A method for producing a transparent polyamide elastomer, which comprises post-polymerizing at 00 to 300°C.