JPH0125737B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel poly(p-phenylene terephthalamides). For more information, see the general formula [In the formula, one of R ₁ and R ₂ has 3 to 3 carbon atoms.
5 is an alkyl group, and the other is hydrogen. Also
R ₃ represents hydrogen, a lower alkyl group, or a lower alkoxy group. Further, n is a number of 2 or more and 20 or less. ] It relates to poly(p-phenylene terephthalamide) represented by these. Thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate obtained from terephthalic acid and aliphatic diols are used as fibers, films, and other molded products due to their excellent mechanical properties, heat resistance, and chemical resistance. Widely used. However, taking polyethylene terephthalate as an example, although it is possible to improve strength, elastic modulus, etc. in fibers and films by uniaxially or biaxially oriented, for example, in tire cords, magnetic tapes, etc., it is possible to improve strength and elastic modulus. Strong and high modulus materials have become desirable. Furthermore, when used as molded products, both polyethylene terephthalate and polybutylene terephthalate generally have a low glass transition temperature or glass transition temperature range, which is one index that determines dimensional stability and usable range. Since the loss of rigidity of molded bodies occurs at relatively low temperatures, it is desired to improve the glass transition temperature or the glass transition temperature range. In order to meet the above-mentioned requirements under these circumstances, Japanese Patent Laid-Open No. 65747/1983 proposes a method of mixing rigid polymers. However, although poly(p-phenylene terephthalamide), which is a typical rigid polymer, can be easily mixed with nylon, it has been difficult to mix it with polyester. This is because poly(p-phenylene terephthalamide) has a very high melting point or is infusible, and there is no common solvent between it and polyester. Also, JP-A-54-
No. 125271 and JP-A-55-123621 propose aromatic amide copolyesters, but because aromatic amides are not repeated continuously, it is difficult to improve strength, improve elastic modulus, and lower glass transition temperature. No significant improvement has been achieved. The present inventors conducted various studies in order to obtain poly(p-phenylene terephthalamide) that can be dispersed in polyester, and as a result, the inventors discovered that a specific group was introduced at the end of poly(p-phenylene terephthalamide). The inventors have discovered that the object can be achieved by the following methods, and have arrived at the present invention. That is, the poly(p-
Phenylene terephthalamide) has the general formula , and at the end

It is characterized by the fact that the group [Formula] is bonded to it. By bonding such a group, the solubility of poly(p-phenylene terephthalamide) is improved, and since it has a common solvent with the polyester, uniform dispersion into the polyester is possible. be. In the poly(p-phenylene terephthalamide) of the present invention, it is necessary that the ortho or meta position of the terminal phenyl group, that is, either _R1 or _R2 , be an alkyl group having 3 to 5 carbon atoms.
Such alkyl groups include n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-
Examples include pentyl group and tert-pentyl group. Among these, tert-butyl group is particularly preferred. When R ₁ and R ₂ are both hydrogen or an alkyl group having 2 or less carbon atoms, the desired effect cannot be obtained. The reason for this is not clear, but it is thought that when a substituent with steric bulk is not bonded to the ortho or meta position, the solubility in a solvent is likely to be low due to good crystallinity. On the other hand, when a sterically bulky alkyl group having 3 to 5 carbon atoms is bonded, the symmetry of the molecule is disturbed and crystallinity is inhibited, so it is presumed that the solubility in the solvent increases. Further, R ₃ is hydrogen, a lower alkyl group, or a lower alkoxy group. Here, the lower alkyl group and lower alkoxy group mean a group having 4 or less carbon atoms. The degree of polymerization of the poly(p-phenylene terephthalamide) of the present invention, that is, n in the above general formula
is not particularly limited, but when n=1, the effect of improving physical properties when dispersed in polyester is low, so it is not preferred. Further, when n is larger than 20, the effect of the terminal group is relatively reduced, and solubility in a solvent tends to be reduced. Therefore, it is usually necessary that n be a number of 2 or more and 20 or less. Note that poly(p
-phenylene terephthalamide) having a polymerization degree distribution is often obtained, and the polymerization degree n here means the average degree of polymerization. The poly(p-phenylene terephthalamide) of the present invention comprises terephthalic acid chloride, p-phenylene diamine and the general formula It can be produced by simultaneously reacting terephthalic acid chloride monophenol derivative esters represented by: The reaction is preferably carried out in a suitable solvent, and examples of the solvent include dimethylacetamide, dimethylformamide, N-methylpyrrolidone, hexamethylphosphoramide, and mixed solvents thereof. These solvents contain about 0.5 to 8% by weight of lithium chloride,
A salt such as calcium chloride may be added.
The reaction is usually carried out by mixing a mixture of terephthalic acid chloride and terephthalic acid chloride monophenol derivative ester with p-phenylenediamine. The reaction proceeds quickly and quantitatively at the same time as the raw materials are mixed, and the reaction proceeds rapidly and quantitatively at the same time as the raw materials are mixed.
-phenylene terephthalamide) is obtained. The reaction temperature is preferably lower than room temperature, and suitably around 0°C (-10°C to 10°C). The terephthalic acid chloride monophenol derivative ester used as a raw material has the formula terephthalic acid chloride.

It can be obtained by reacting a phenol derivative represented by the formula. During the reaction, a tertiary amine such as triethylamine, tri-n-propylamine, tri-n-butylamine, N-ethylpiperidine, N-ethylmorpholine, etc. may be added in order to smoothly proceed with the esterification reaction. The obtained terephthalic acid chloride monophenol derivative ester can be used after being purified, or the reaction product may be used as it is. In this case, it is convenient to further add terephthalic acid chloride to the reaction product or to use an excess of terephthalic acid chloride from the beginning, since it can be immediately subjected to the reaction with p-phenylenediamine. The amount of terephthalic acid chloride and terephthalic acid chloride monophenol derivative ester to be used is preferably in the range of 0.01 to 0.7 mol per 1 mol of terephthalic acid chloride. Generally, the larger the amount of terephthalic acid chloride monophenol derivative ester used, the lower the degree of polymerization of poly(p-phenylene terephthalamide) obtained, and the smaller the amount used, the higher the degree of polymerization obtained. Since the reaction is almost quantitative, terephthalic acid chloride and p-
Preferably, the phenylene diamines are used in approximately equimolar proportions. The resulting poly(p-phenylene terephthalamide) has trace amounts of carboxyl group ends and amine ends, but more than 90% has phenol derivative ends, and can be mixed into polyester resin without purification. be able to. The poly(p-phenylene terephthalamide) of the present invention can improve the strength, elastic modulus, etc. of the resin by uniformly mixing it with a polyester resin such as polyethylene terephthalate or polybutylene terephthalate and molding it. Mixing into the polyester resin is carried out using a solution of poly(p-phenylene terephthalamide) in an amide solvent (e.g. dimethylacetamide, dimethylformamide, N-
This is done by mixing methylpyrrolidone, hexamethylphosphoramide) and a dimethyl sulfoxide solution of polyester to form a homogeneous solution, and then solidifying by contacting with a non-solvent such as water or methanol, or by evaporating the solvent. Can be done. The obtained poly(p-phenylene terephthalamide) mixed polyester resin composition can be molded as it is by a method such as melt molding. Alternatively, the above-mentioned mixed solution may be shaped as it is,
A molded article can also be obtained by solidifying by contacting with a non-solvent. The appropriate blending ratio of poly(p-phenylene terephthalamide) to polyester is 1 to 20 parts by weight per 100 parts by weight of polyester.
If it is less than 1 part by weight, the effect of improving physical properties will not be sufficient;
Moreover, if it exceeds 20 parts by weight, moldability will deteriorate, which is not preferable. The polyester resin composition containing poly(p-phenylene terephthalamide) of the present invention can be melt-molded or dissolved in a solvent and molded to produce fibers, films, and other molded products. , high strength, and high modulus of elasticity, making it extremely useful for applications such as tire cords and magnetic tapes. Further, the resin composition can be used as a raw material because a copolymer of polyester and poly(p-phenylene terephthalamide) can be easily produced by solid-phase polymerization. The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 5, Comparative Examples 1 to 2 400 ml of N-methylpyrrolidone was placed in a 1 liter four-necked separable flask equipped with a stirrer, a nitrogen gas inlet tube, and a calcium chloride tube, and the flask was cooled to 0°C.
Next, add 3.00 g of the phenol derivative shown in Table 1,
Subsequently, 16.24 g of terephthalic acid chloride was added and dissolved, and then 30 ml of triethylamine was added and reacted for 30 minutes to synthesize a terephthalic acid chloride monophenol derivative ester. Next, 100 ml of N-methylpyrrolidone in which 7.56 g of p-phenylenediamine was dissolved was added dropwise into the reaction vessel over a period of 30 minutes.
After further reaction for 1 hour, the reaction solution was added to a large amount of water to cause precipitation. The precipitate was filtered through a glass filter, washed several times with water, and dried under vacuum. When the terminal carboxyl group and amino group of the obtained compound were quantified by neutralization titration method, as shown in Table 1, the carboxyl group was 60~
Since the theoretical total number of terminal groups was about 1500 μeq/g, with 240 μeq/g and 0 to 20 μeq/g of amino groups, it is considered that most of the polymers have phenol derivatives bonded to their ends. Furthermore, a substituent bonded to the phenol derivative was detected by NMR analysis. Considering the above analysis results and the raw materials used, the obtained compound is considered to be poly(p-phenylene terephthalamide) with the phenol derivative shown in Table 1 bonded to the terminal. Furthermore, the molar ratio of the substituent bonded to the phenol derivative and the phenyl ring was measured by NMR analysis, and the average degree of polymerization was calculated. These results are summarized in Table 1.

【table】

[Table] As can be seen from Table 1, when either R ₁ or R ₂ is an alkyl group having 3 to 5 carbon atoms, the resulting poly(p-phenylene terephthalamide) is The solubility is good and, as a result, dispersion in polyester is possible. However, outside this range, the solubility in solvents is poor and dispersion in polyester is impossible. Example 6 400 ml of N-methylpyrrolidone was placed in a 1 liter separable flask and cooled with ice water. Add 20.3g of terephthalic acid chloride, stir to dissolve, and o-tert.
Add 10.1 g of butylphenol, then add 30 ml of triethylamine, and react for 30 minutes. Then p
- A solution of 7.20 g of phenylenediamine dissolved in 150 ml of N-methylpyrrolidone was added dropwise over 30 minutes, and the reaction was continued for an additional hour. The reaction solution was added to a large amount of water, and the precipitate was separated and dried to obtain poly(p-phenylene terephthalamide) in which R ₁ is a tert-butyl group, and R ₂ and R _{3 are} hydrogen. The carboxyl group of the obtained polymer was 190 μeq/g, and the amino group was
It was 30μeq/g. The degree of polymerization determined by NMR analysis was 2, indicating good solubility in solvents. Moreover, the melting point was over 400°C. Add 2.5 g of this polymer to 50 g of N-methylpyrrolidone.
ml, and a solution of 50 g of polyethylene terephthalate dissolved in 500 ml of dimethyl sulfoxide and 150 ml of dimethyl sulfoxide.
Mixed at ℃. The mixed solution was a brownish transparent solution and was moldable. This solution was added to a large amount of water, and the polymer was precipitated and separated, followed by vacuum drying to obtain a poly(p-phenylene terephthalamide)-containing polyethylene terephthalate resin. The polyester of the obtained resin was melted by heating to 260° C. or higher, and it was moldable. Example 7 Put 400 ml of dimethylacetamide into a 1 liter separable flask, add 10 g of anhydrous lithium chloride, dissolve at room temperature, and then cool to 0°C. o-tert
Butylphenol 0.60g and triethylamine 5.4
ml plus 16.24 terephthalic acid chloride
g and reacted for 15 minutes, then α-picoline 20
ml of finely powdered p-phenylenediamine.
8.44g was added at once and reacted at 0°C for 3 hours.
The reaction solution was added to a large amount of water, and the resulting precipitate was separated and dried. The resulting polymer had good solubility in solvents, and the degree of polymerization determined from the intrinsic viscosity in a 96% concentrated sulfuric acid solution (25°C) was 18. The obtained polymer was dissolved in N-methylpyrrolidone containing 4% by weight of anhydrous lithium chloride and heated at 150°C.
was mixed with a solution of polyethylene terephthalate in dimethyl sulfoxide to obtain a brownish transparent solution. This solution was moldable. Next, this solution was added to a large amount of water, and the polymer was precipitated and separated to obtain poly(p-phenylene terephthalamide)-containing polyethylene terephthalate. The obtained sample was vacuum dried, then melted at 285°C using a heating press, and quickly placed in ice water to obtain a film with a thickness of 0.3 mm. The obtained film was superior in heat resistance, strength, etc. compared to a similarly obtained film made of polyethylene terephthalate alone.

Claims (1)

[Claims] 1. General formula [In the formula, one of R ₁ and R ₂ has 3 to 3 carbon atoms.
5 is an alkyl group, and the other is hydrogen. Further, R ₃ represents hydrogen, a lower alkyl group, or a lower alkoxy group. Further, n is a number of 2 or more and 20 or less. ] Poly(p-phenylene terephthalamide) represented by: 2. The poly(p-phenylene terephthalamide) according to claim 1, wherein R ₁ is a butyl group.