JPH0680751A - Polyamide resin and its production - Google Patents

Abstract

PURPOSE:To obtain a melt-moldable polyamide resin excellent in heat resistance by reacting an arom. dicarboxylic acid, an aliph. diisocyanate, and an arom. diisocyanate using an arom. monocarboxylic acid as a blocking agent. CONSTITUTION:1 mol of an arom. dicarboxylic acid of formula I (wherein Ar1 is a divalent arom. group), 0.475-0.525mol of an aliph. diisocyanate of formula II (wherein R1 is a single bond or a divalent org. group), an 0.1mol or lower of a blocking agent selected from among arom. monocarboxylic acids are reacted in the presence of an alkali metal compd. catalyst in an aprotic polar solvent at 180 deg.C or higher. Then, 0.475-0.525mol of an arom. diisocyanate of formula III (wherein Ar2 is a divalent arom. group) is added to the reaction system and the reaction is continued at 140 deg.C, giving a melt-moldable polyamide resin of formula IV (wherein Ar1, Ar2, and R1 are each as defined above) which consists of repeating units regularly arranged and has molecular terminals blocked by arom. rings optionally substd. by groups nonreactive with isocyanate and carboxyl groups.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel polyamide resin and a method for producing the same. More specifically, the present invention relates to a melt-moldable aliphatic or aromatic polyamide copolymer having excellent heat resistance and a method for producing the same.

[0002]

2. Description of the Related Art A wholly aromatic polyamide (aramid) is generally a crystalline polymer having a high melting point and is widely used as a material suitable for fibers and the like because of its excellent heat resistance and strength. However, these wholly aromatic polyamides have a melting point higher than the decomposition start temperature thereof, are substantially incapable of being melt-molded, and are subject to molding conditions such as solution molding. As a method for solving these problems, attempts have been made to introduce an aliphatic chain into one of the monomer components to impart melt fluidity. For example, JP-A-59
No. 53536 discloses a molding polyamide comprising an aromatic dicarboxylic acid containing terephthalic acid as a main component and a straight-chain aliphatic alkylenediamine, and JP-A-59-161.
No. 428, crystalline copolyamides from terephthalic acid, isophthalic acid and C6 diamines are disclosed in
Japanese Patent Publication No. 2004024 proposes a method for producing an aliphatic dicarboxylic acid containing adipic acid as a main component and a polyamide containing metaxylylenediamine as a main component. However, in the method of introducing a large amount of an aliphatic chain into one of the diamine component forming these polyamides, or one of the monomer components of the carboxylic acid or the carboxylic acid derivative, although the melt fluidity is imparted, thermal stability, heat resistance, etc. There was a problem that it decreased. On the other hand, as a polyamide containing no aliphatic chain in the main chain and having improved melt fluidity, a monomer containing an ether bond as proposed in JP-A-62-177021 is used. Attempts have been made to impart melt fluidity by using a special monomer, such as a method and a method using a monomer containing an indane ring as proposed in JP-A-63-172732. In either case, the cost was high and the cost was not satisfactory.

[0003]

SUMMARY OF THE INVENTION The present invention provides a polyamide resin capable of solving at least some of the above-mentioned drawbacks of the prior art, for example, a polyamide resin having excellent heat resistance and capable of being melt-molded. It is an object of the present invention to provide a method for producing such a resin.

[0004]

As a result of research, the inventors of the present invention have solved the problem of the present invention by sealing the polymer molecule end with a specific end-capping group to give regularity to the molecular arrangement. The inventor has arrived at the present invention knowing that a solvable polyamide resin can be obtained. According to the present invention, such a polyamide resin is an aprotic polar solvent in the presence of an alkali metal compound as a catalyst, using an aromatic dicarboxylic acid, an aliphatic diisocyanate, and an aromatic diisocyanate as a terminal blocking agent. It can be obtained by reacting in.

The first invention of the present invention is the following formula (I):

[Chemical 9] An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. A melt-moldable polyamide resin characterized by being sealed,

A second invention of the present invention is the following formula (I):

[Chemical 10] An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. Upon possible to produce a melt-moldable polyamide resin, characterized in that sealed the following formula _{(III) HOOC-Ar 1 -COOH} (III) ( wherein Ar1 represents a divalent aromatic group.) in the aromatic carboxylic acid 1 mol represented in the following formula _{(IV) OCN-CH 2 -R} 1 -CH 2 -NCO (IV) ( wherein, R ₁ comprises a direct or 1 or more carbon atoms Two
Represents a valence group. ) 0.475 to 0.525 mol of an aliphatic diisocyanate represented by the formula (1) and 0.1 mol or less of an unsubstituted aromatic monocarboxylic acid per mol of the aromatic dicarboxylic acid of the formula (III), or an isocyanate or a carboxylic acid. At least 180 ° C. in an aprotic polar solvent in the presence of an alkali metal compound as a catalyst, at least one end-capping agent selected from the group consisting of aromatic monocarboxylic acids having a substituent that does not react with after allowed to, aromatic diisocyanates represented by the following formula _{(V) OCN-Ar 2 -NCO} (V) 0.475~0.5
A method for producing a polyamide resin, comprising adding 25 mol and reacting at 140 ° C. or higher,

A third invention of the present invention is the following formula (I):

[Chemical 11] An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. In producing a melt-moldable polyamide resin characterized by being sealed, the following formula (III) HOOC-Ar ₁ -COOH (III) (wherein Ar ₁ represents a divalent aromatic group). ) To 1 mol of the aromatic carboxylic acid represented by the formula (V) OCN-Ar ₂ -NCO (V) represented by the aromatic diisocyanate 0.475-0.
525 mol, and 0.1 mol or less of an unsubstituted aromatic monocarboxylic acid per mol of the aromatic dicarboxylic acid of the formula (III), or an aromatic monocarboxylic acid having a substituent that is not reactive with isocyanate or carboxylic acid. At least one end-capping agent selected from the group consisting of 140 ° C. in an aprotic polar solvent in the presence of an alkali metal compound as a catalyst.
2 After reacting at least, in the following formula _{(IV) OCN-CH 2 -R} 1 -CH 2 -NCO (IV) ( wherein, R ₁ is comprising direct or one or more carbon atoms
Represents a valence group. (4) Add 0.475 to 0.525 mol of the aliphatic diisocyanate and react at 180 ° C. or higher to produce a polyamide resin.

In the present invention, the substituent Ar ₁ is a divalent aromatic group. Examples of this aromatic group include bifunctional aromatic groups derived from benzene, naphthalene, diphenyl, diphenyl sulfone, diphenyl ether, benzophenone, perylene, diphenylalkane, and the like. Ar ₁ is

[Chemical 12] It may be a bifunctional aromatic group.

The substituent R ₁ is a direct bond or a divalent group containing at least one carbon atom. Examples of the divalent group containing at least one carbon atom include an alkylene group, an alkylene group containing an element other than carbon, a divalent aromatic group such as phenylene, naphthylene, a divalent bicyclo (bicyclic group). Examples include groups derived from a (fused ring) compound. R ₁ may be a direct bond or a divalent group as described below.

[Chemical 13]

Further, the substituent Ar ₂ is a divalent aromatic group, for example, phenylene, substituted phenylene (alkyl-substituted phenylene, alkoxy-substituted phenylene, halo-substituted phenylene, etc.), further unsubstituted or substituted diphenylalkane, triphenylalkane. And diphenyl sulfide, diphenyl sulfone, diphenyl ether, benzophenone, biphenyl, naphthalene, anthraquinone, anthracene, azobenzene and the like. Ar ₂ may be the following divalent group.

[Chemical 14]

Examples of the aromatic dicarboxylic acid represented by the general formula (III) include isophthalic acid, terephthalic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid and naphthalene-2,6- Dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, perylene-
1,9-dicarboxylic acid, perylene-2,9-dicarboxylic acid,
4,4'-dicarboxydiphenylmethane, 2- (4,4'-dicarboxyphenyl) propane and the like can be mentioned.

Examples of the aliphatic diisocyanate represented by the general formula (IV) include 1,2-diisocyanatoethane, 1,3-diisocyanatopropane, tetramethylene-1,4-diisocyanate and pentamethylene. Aliphatic diisocyanate derivatives such as 1,5-diisocyanate, hexamethylene-1,6-diisocyanate, nonamethylene-1,9-diisocyanate, decamethylene-1,10-diisocyanate, ω, ω'-dipropyl ether diisocyanate, and meta Aromatic diisocyanate derivatives having a substituent on the side chain such as xylylene diisocyanate and para-xylylene diisocyanate, and 2,4-diisocyanatomethyl [2,2,1] heptane, 2,5-diisocyanatomethyl Examples include bicyclo (bicyclic condensed ring) compounds such as [2,2,1] heptane. , In particular hexamethylene - 1,6-diisocyanate, preferred since m-xylylene diisocyanate is inexpensive easy to industrial availability.

Examples of the aromatic diisocyanate represented by the general formula (V) include phenylene-1,3-diisocyanate, phenylene-1,4-diisocyanate, tolylene-2,6-diisocyanate and tolylene-2,4-diisocyanate. , 1-methoxybenzene-2,4-diisocyanate, 1-chlorophenylene diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylsulfide-4,4'- Diisocyanate, diphenyl sulfone-4,4'-diisocyanate, diphenyl ether-
4,4'-diisocyanate, diphenyl ether-3,4'-
Diisocyanate, diphenylketone-4,4'-diisocyanate, naphthalene-2,6 diisocyanate, naphthalene-1,4 diisocyanate, naphthalene-1,5-diisocyanate, 2,4'-biphenyldiisocyanate, 4,
4'-biphenyl diisocyanate, 3,3'-methoxy-4,
4'-biphenyl diisocyanate, anthraquinone-
2,6-diisocyanate, triphenylmethane-4,4'-
Diisocyanate, azobenzene-4,4'-diisocyanate and the like are mentioned, and particularly tolylene-2,4-diisocyanate, diphenylmethane-4,4'-diisocyanate and naphthalene-1,5-diisocyanate are industrially easily available and inexpensive. It is preferable because it exists.

The molecular terminal blocking group of the polymer used in the present invention is an unsubstituted aromatic ring group or an aromatic ring group substituted with a group having no reactivity with isocyanate or carboxylic acid. This aromatic ring may be a monocyclic aromatic group, a condensed polycyclic aromatic group, or a polycyclic aromatic group in which aromatic groups are connected to each other directly or by a bridging member. For example, unsubstituted aromatic ring groups derived from benzene, diphenyl alkane, diphenyl sulfone, diphenyl sulfoxide, diphenyl sulfide, diphenyl ether, benzophenone, naphthalene, and the like, and their alkyl-substituted, alkoxy-substituted, halogen-substituted aromatic ring groups, for example, , Methyl-substituted, methoxy-substituted, and chloro-substituted aromatic groups. In particular, when the molecular end of the polymer is sealed with an unsubstituted aromatic group derived from benzene, heat resistance is improved, which is preferable.

As the molecular end-capping agent used in the present invention, it is possible to use a compound having an unsubstituted aromatic ring group or an aromatic ring group substituted with a group having no reactivity with isocyanate or carboxylic acid. it can. This aromatic ring may be a monocyclic aromatic group, a condensed polycyclic aromatic group, or a polycyclic aromatic group in which aromatic groups are connected to each other directly or by a bridging member. Examples of the molecular end capping agent include benzoic acid, diphenylmethanecarboxylic acid, diphenylsulfonecarboxylic acid, diphenylsulfoxidecarboxylic acid, diphenylsulfidecarboxylic acid, diphenylethercarboxylic acid, benzophenonecarboxylic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, anthracenecarboxylic acid. Monocarboxylic acids such as acids, or alkyl substitutions thereof,
Examples thereof include alkoxy-substituted and halogen-substituted monocarboxylic acids. Preferably a monocarboxylic acid represented by the following formula,

[Chemical 15] And a derivative in which the aromatic ring thereof is substituted with a group having no reactivity with isocyanate or carboxylic acid.

It will be apparent to those skilled in the art that, in various aspects of the invention, the reactants described in this invention used to make the resin may have isomers. Therefore, unless otherwise stated, references to reactants are meant to include all such isomers. As the molecular end cap,
In particular, benzoic acid is preferable because it is industrially easily available and inexpensive, and the thermal stability of the polymer using these molecular end-capping agents is extremely superior to that of the polymers not using it.

Examples of alkali metal compounds used as catalysts in the process of the present invention are mono- and / or di- and / or tri- and / or tetralithium salts of dicarboxylic acids, tricarboxylic acids and tetracarboxylic acids,
Alkali metal salts of polyvalent carboxylic acids such as sodium salts, potassium salts, rubidium salts, cesium salts, francium salts, etc., alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, francium carbonate, etc. Alkali metal hydrogen carbonate such as lithium hydrogen, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, francium hydrogen carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, Alkali metal hydroxides such as francium hydroxide, lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride,
Examples thereof include alkali metal fluorides such as cesium fluoride and francium fluoride. Particularly, sodium salt and potassium salt are preferable. You may use the said alkali metal compound individually or in mixture of 2 or more types.

As the aprotic polar solvent used in the present invention, for example, N, N-dimethylacetamide, N, N
-Dimethylformamide, N-methylpyrrolidone, γ-
Chain or cyclic amides such as butyrolactone, hexamethylphosphoric triamide or phosphorylamides,
Or dimethyl sulfoxide, diphenyl sulfone,
These are sulfoxides or sulfones such as tetramethylene sulfone and ureas such as tetramethylurea and N, N'-dimethylethyleneurea. These solvents need to be used in a substantially anhydrous state. Other solvents inert to the polymerization reaction, such as benzene, toluene and xylene, can be mixed and used.

In the present invention, in order to produce a melt-moldable polyamide having excellent heat resistance, the first stage is based on 1 mol of the aromatic dicarboxylic acid represented by the general formula (III). In the presence of the alkali metal compound, the aliphatic diisocyanate represented by the general formula (IV) is added in the range of 0.475 to 0.525 mol, and further the molecular terminal blocking agent is added in an amount of 0.1 mol or less. After heating and reaction in an aprotic polar solvent at a temperature of 180 ° C. or higher, the aromatic diisocyanate represented by the general formula (V) is further added to the second stage in an amount of 0.475 with respect to 1 mol of the aromatic dicarboxylic acid. It is necessary to add in the range of up to 0.525 mol and to heat and react at a temperature of 140 ° C or higher.

Alternatively, in the first stage, for 1 mol of the aromatic dicarboxylic acid represented by the general formula (III), the general formula (V) is added.
The aromatic diisocyanate represented by
After addition of 0.1 mol or less of a molecular end-capping agent in the range of 525 mol, the mixture is heated at a temperature of 140 ° C. or higher in an aprotic polar solvent in the presence of an alkali metal compound, and then 2 It is necessary to add the aliphatic diisocyanate represented by the general formula (IV) to the stage in the range of 0.475 to 0.525 mol with respect to 1 mol of the aromatic dicarboxylic acid and to heat the mixture at a temperature of 180 ° C. or higher. .

The molar ratio of the aromatic dicarboxylic acid represented by the general formula (III) and the aliphatic diisocyanate represented by the general formula (IV) used in the present invention is 1 mol of the aromatic dicarboxylic acid to the aliphatic diisocyanate. Aromatic diisocyanate 0.475
To 0.525 mol is preferable, and 0.49 to 0.5
The range of 1 mol is more preferable. If the molar ratio is less than 0.475, the melt flowability of the obtained polymer will be poor, or if it exceeds 0.525, the glass transition temperature of the polymer will be lowered, and a polymer having excellent heat resistance cannot be obtained.

Further, the molar ratio of the aromatic diisocyanate represented by the general formula (V) is 0.475 to 0.5 per 1 mol of the aromatic dicarboxylic acid.
The range of 25 mol is preferable, and the range of 0.49 to 0.51 mol is more preferable. If the molar ratio is less than 0.475, the melt fluidity of the obtained polymer will be poor, and if the molar ratio exceeds 0.525, the glass transition temperature of the polymer will be lowered and a polymer having excellent heat resistance cannot be obtained.

The amount of the molecular end capping agent is preferably 0.1 mol or less per 1 mol of the aromatic dicarboxylic acid, and 0.0
It is more preferably 8 mol or less. If the amount of the molecular end-capping agent exceeds 0.1 mol per mol of the aromatic dicarboxylic acid, the molecular weight of the obtained polymer will decrease and the heat resistance will decrease.

Regarding the reactivity between the aromatic carboxylic acid and the aliphatic or aromatic diisocyanate, benzoic acid was examined as a model compound, and as a result, there was a large difference in the rate of amidation between the aliphatic diisocyanate and the aromatic diisocyanate. I found something. Therefore, in order to produce a polyamide resin having a controlled molecular arrangement, the aliphatic diisocyanate and the aromatic diisocyanate having different reactivities are not reacted at the same time and produced, but under the reaction optimal condition of the aliphatic diisocyanate in the first step. , Diamide dicarboxylic acid is formed, and the polycondensation reaction is performed in the second stage under the optimum reaction conditions of the aromatic diisocyanate. Alternatively, in the first stage, a diamide dicarboxylic acid is formed under the optimal reaction conditions of the aromatic diisocyanate, and the polycondensation reaction is performed under the optimal reaction conditions of the aliphatic diisocyanate in the second stage. There is no problem even if the product is isolated and subjected to a polycondensation reaction.

Polyamide resin having a controlled molecular arrangement is
It means that the aliphatic isocyanate and the aromatic isocyanate are not randomly arranged with respect to the aromatic carboxylic acid but are alternately arranged. The reaction of the aliphatic diisocyanate requires a temperature of 180 to 250 ° C.
The range of 0 to 230 ° C is more preferable. If it is less than 180 ° C, the reactivity of carboxylic acid and isocyanate is lowered, which is not preferable, and if it exceeds 250 ° C, a side reaction proceeds, which is not preferable. The reaction of aromatic diisocyanate is 140
A temperature of ~ 250 ° C is required, and a temperature range of 180-230 ° C is more preferred. If it is lower than 140 ° C, the reactivity of carboxylic acid and isocyanate is lowered, which is not preferable, and if it exceeds 250 ° C, a side reaction proceeds, which is not preferable. The reaction time is
It is usually 1 to 20 hours. The reaction can be completed at the time when carbon dioxide produced as a by-product is substantially not recognized. The addition amount of the alkali metal compound is preferably in the range of 0.5 to 20 mol%, and particularly preferably 1.0 to 10 mol% with respect to the aromatic dicarboxylic acid.

Generally, the concentration of the raw material monomers (aromatic dicarboxylic acid + diisocyanate) is selected in the range of 50 to 400 g / l. The selection of this concentration depends on the reactivity of the raw material monomers and the solubility of the polymer in the polymerization solvent. Done by When the polymerization is started at a high concentration, it is preferable to add the solvent continuously or discontinuously in some cases so that the stirring may not be hindered by the increase in viscosity during the polymerization. In the present invention, the average molecular weight (G
The polystyrene of PC and the weight average molecular weight according to the standard) are preferably 10,000 or more, particularly preferably 20,000 or more.

[0027]

EXAMPLES The present invention will be described in detail below with reference to examples.
The physical properties of the polymers obtained in Examples and Comparative Examples were measured by the following methods. Average molecular weight: dilute the polymerization liquid with N-methylpyrrolidone,
The curve of the molecular weight distribution curve was measured using GPC, and the average molecular weight was obtained by the polystyrene standard. Flow temperature: (Shimadzu) The apparent melt viscosity measured using a flow tester is 1
The temperature to reach 0000 Poise.

Example 1 Isophthalic acid 2 was placed in a 500 ml separable flask equipped with a stirrer, thermometer, cooling condenser and dropping funnel.
0.99g (0.1263mol), potassium fluoride 0.148g (0.002
40 mol), 0.029 g (0.00024 g) of benzoic acid and 200 ml of N, N'-dimethylethyleneurea were charged and dissolved in a nitrogen atmosphere, and the internal temperature was raised to 140 ° C while stirring this solution. Tolylene-2,4-diisocyanate 11.3 on the dropping funnel
3 g (0.06507 mol) was weighed out and added at once to the flask and reacted at 180 ° C. for 2 hours. Furthermore, we measured 10.41 g (0.06186 mol) of hexamethylene-1,6-diisocyanate in the dropping funnel and added it to the flask at one time.
When the temperature was raised to 0 ° C, the reaction was violent and the generation of carbon dioxide was observed. When stirring was continued at 220 ° C. for 1 hour, the color of the solution changed to yellow and the viscosity increased. After further heating for 1 hour for aging, the mixture was cooled to room temperature, and the polymerization liquid was put into water under high-speed stirring to obtain a polymer powder. The polymer powder was further washed 3 times with hot water, and finally with methanol, and then dried in an inert oven at 170 ° C for 8 hours to 29.6.
g of polymer powder was obtained. The average molecular weight of the polymer was 164,000. The glass transition temperature measured by DSC was 191 ° C., and the 5% decomposition temperature in air was 434 ° C., indicating excellent heat resistance. Furthermore, it had a flow melting temperature of 307 ° C. and had a heat melting property capable of injection molding.

Examples 2 to 5 In the experimental apparatus shown in Example 1, an aromatic dicarboxylic acid, an aliphatic diisocyanate and an aromatic diisocyanate were used as the first component.
Polymerization was carried out in the same manner as in Example 1 except that the reaction was carried out by inserting the compounds in the order shown in the table, and further reacting the aliphatic diisocyanate at 180 ° C and the aromatic diisocyanate at 140 ° C. Table 1 shows the respective physical properties of the polymer obtained after the post-treatment.

[Table 1]

Reference Example 0.0174 g (0.0003 mol) of potassium fluoride, 7.4713 g (0.0612 mol) of benzoic acid, and N, N'-dimethylethyleneurea 109.84 were placed in a four-necked flask equipped with a stirrer, a thermometer, and a cooling condenser. g was charged in a nitrogen atmosphere and dissolved.
After keeping the temperature constant, 4.9489 g (0.029 mol) of hexamethylene-1,6-diisocyanate was charged all at once, and the disappearance amount of hexamethylene-1,6-diisocyanate at each time was quantified by liquid chromatography. The reaction rate constant k of amidation was determined at each temperature by the integral method. Table 2 shows the obtained reaction rate constants at each temperature.

[Table 2]

Comparative Example 1 20.9 terephthalic acid was placed in a 500 ml separable flask equipped with a stirrer, a thermometer, a cooling condenser and a dropping funnel.
8 g (O.1263 mol), potassium fluoride 0.147 g (0.0025)
(3 mol) and 200 ml of N, N'-dimethylethyleneurea were charged into a nitrogen atmosphere and dissolved. Tolylene on the dropping funnel-2,4
-Only 21.99 g (0.1263 mol) of diisocyanate was weighed and added at once to the flask. When this solution was stirred and the internal temperature was raised to 200 ° C, the reaction was violent at 140 ° C and generation of carbon dioxide was observed. When stirring was continued at 200 ° C. for 1 hour, the color of the solution changed to yellow and the viscosity increased. After further heating for 1 hour for aging, the mixture was cooled to room temperature, and the polymerization liquid was poured into water under high-speed stirring to obtain a polymer powder. The powder was further washed with hot water three times, and finally with methanol, and then dried in an inert oven at 200 ° C. for 8 hours to obtain 25.5 g of a polymer powder. This polymer had an average molecular weight of 230,000 and a glass transition temperature of 250 ° C or higher, and had sufficient heat resistance as a heat resistant resin, but it did not exhibit melt flowability at all, and melt molding and injection molding were impossible. Met.

Comparative Example 2 Reaction and post-treatment were carried out in the same manner as in Comparative Example 1 except that the diisocyanate of Comparative Example 1 was changed to hexamethylene-1.6-diisocyanate 21.2 g (0.1263 mol) and the catalyst was changed to potassium carbonate 0.23 g (0.0017 mol). I went. The obtained polymer had an average molecular weight of 96,000 and a glass transition temperature lower by 110 ° C., and did not have sufficient heat resistance as a heat resistant resin.

Comparative Example 3 Polymerization and post-treatment were conducted in the same manner as in Comparative Example 1 except that 21.35 g (0.1461 mol) of adipic acid, 27.48 g (0.1460 mol) of metaxylylene diisocyanate and 0.16 g (0.0027 mol) of potassium fluoride were used. I went. The obtained polymer had an average molecular weight as low as 65,000 and a glass transition temperature as low as 60 ° C. and did not have sufficient heat resistance as a heat resistant resin.

[0034]

The polyamide resin of the present invention has excellent heat resistance and can be melt-molded. Further, the method for producing a polyamide resin in the present invention is practical and economical.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Yamaguchi 1191 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (13)

[Claims] 1. The following formula (I): An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. A melt-moldable polyamide resin characterized by being sealed. 2. Ar ₁ in the formula (I) is represented by the following formula: The polyamide resin according to claim 1, which is a divalent group represented by: 3. R ₁ in formula (I) is represented by the following formula: The polyamide resin according to claim 1, which is a direct bond or a divalent group represented by: 4. Ar ₂ in formula (I) is represented by the following formula: The polyamide resin according to claim 1, which is a divalent group represented by: 5. A polymer molecule terminal blocking group selected from the group consisting of an unsubstituted aromatic monocarboxylic acid, or an aromatic monocarboxylic acid having a substituent that is not reactive with isocyanate or carboxylic acid. The polyamide resin according to claim 1, which is an aromatic group derived from 6. A polymer molecule end-capping group is represented by: The polyamide resin according to claim 1, which is an aromatic group derived from the above compound having a substituent that is not reactive with isocyanate and carboxylic acid. 7. The polyamide resin according to claim 1, wherein the polymer molecule terminal blocking group is a group derived from benzoic acid. 8. The following formula (I): An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. Upon possible to produce a melt-moldable polyamide resin, characterized in that sealed the following formula _{(III) HOOC-Ar 1 -COOH} (III) ( wherein Ar1 represents a divalent aromatic group.) in the aromatic carboxylic acid 1 mol represented in the following formula _{(IV) OCN-CH 2 -R} 1 -CH 2 -NCO (IV) ( wherein, R ₁ comprises a direct or 1 or more carbon atoms Two
Represents a valence group. ) 0.475 to 0.525 mol of an aliphatic diisocyanate represented by the formula (1) and 0.1 mol or less of an unsubstituted aromatic monocarboxylic acid per mol of the aromatic dicarboxylic acid of the formula (III), or an isocyanate or a carboxylic acid. At least 180 ° C. in an aprotic polar solvent in the presence of an alkali metal compound as a catalyst, at least one end-capping agent selected from the group consisting of aromatic monocarboxylic acids having a substituent that does not react with after allowed to, aromatic diisocyanates represented by the following formula _{(V) OCN-Ar 2 -NCO} (V) 0.475~0.5
A method for producing a polyamide resin, which comprises adding 25 mol and reacting at 140 ° C. or higher. 9. The following formula (I): An aromatic ring having a repeating unit whose molecular sequence is controlled and having no substituent at the molecular end of the polymer, or an aromatic group substituted with a group having no reactivity with isocyanate or carboxylic acid. In producing a melt-moldable polyamide resin characterized by being sealed, the following formula (III) HOOC-Ar ₁ -COOH (III) (wherein Ar ₁ represents a divalent aromatic group). ) To 1 mol of the aromatic carboxylic acid represented by the formula (V) OCN-Ar ₂ -NCO (V) represented by the aromatic diisocyanate 0.475-0.
525 mol, and 0.1 mol or less of an unsubstituted aromatic monocarboxylic acid per mol of the aromatic dicarboxylic acid of the formula (III), or an aromatic monocarboxylic acid having a substituent that is not reactive with isocyanate or carboxylic acid. At least one end-capping agent selected from the group consisting of 140 ° C. in an aprotic polar solvent in the presence of an alkali metal compound as a catalyst.
2 After reacting at least, in the following formula _{(IV) OCN-CH 2 -R} 1 -CH 2 -NCO (IV) ( wherein, R ₁ is comprising direct or one or more carbon atoms
Represents a valence group. ) Addition of 0.475 to 0.525 mol of an aliphatic diisocyanate represented by the formula (1) and reaction at 180 ° C or higher. 10. The end-capping agent is represented by: And a member selected from the above-mentioned compounds having a substituent that is not reactive with isocyanate and carboxylic acid, The method according to claim 8 or 9, wherein 11. The manufacturing method according to claim 8, wherein the sealing agent is benzoic acid. 12. The alkali metal compound is at least one selected from the group consisting of alkali metal salts of polyvalent carboxylic acids, alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal hydroxides or alkali metal fluorides. The manufacturing method according to claim 8 or 9, wherein: 13. The aprotic polar solvent is an amide,
The method according to claim 8 or 9, wherein the method is at least one selected from the group consisting of phosphorylamides, sulfones, sulfoxides and ureas.