JPS6313445B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic polyesteramide. More specifically, polyalkylene terephthalate solutions and the general formula [In the formula, either R ₁ or R ₂ has 3 to 5 carbon atoms
is an alkyl group, and the other is hydrogen. Also,
R ₃ represents hydrogen, a lower alkyl group, or a lower alkoxy group, and n represents 2 or a number of 2 or more. ] It relates to a method for producing an aromatic polyester amide, which comprises uniformly mixing a poly(p-phenylene terephthalamide) solution represented by the formula above and then reacting the product in a solid phase state. Polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate obtained from terephthalic acid and fatty acid diols are widely used as fibers, films, and other molded products due to their excellent mechanical properties, heat resistance, and chemical resistance. It's being 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 of the indicators that determines dimensional stability and usable range. Since the loss of body stiffness is caused at relatively low temperatures, the glass transition temperature,
Alternatively, there is a demand for improvement in 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 polyalkylene terephthalate. The reason is,
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 polyalkylene terephthalate. In addition, aromatic amide copolyester polyesters have been proposed in JP-A-54-125271 and JP-A-55-123621, but because the aromatic amide is not repeated continuously, no great effect can be obtained. It hasn't been done yet. Furthermore, it is expected that a large improvement effect can be obtained by copolymerizing poly(p-phenylene terephthalamide) with polyalkylene terephthalate, but as mentioned above, poly(p-phenylene terephthalamide) is It was difficult to mix with terephthalate, and therefore it was difficult to carry out a copolymerization reaction. As a result of various studies on methods for copolymerizing poly(p-phenylene terephthalamide) to polyalkylene terephthalate, the present inventors found that it is possible to bond a specific phenol derivative to the terminal of poly(p-phenylene terephthalamide). The present inventors have discovered that uniform mixing with polyalkylene terephthalate is possible, and as a result, copolymerization is also possible. Note that "uniform mixing" here refers to a state in which the materials are uniformly dispersed in a microscopic region of 1 μm or less. The present invention has the greatest feature in that it uses poly(p-phenylene terephthalamide) represented by the following general formula. Poly(p-phenylene terephthalamide), which has a specific phenol derivative bonded to its terminal, has dramatically improved solubility in solvents compared to poly(p-phenylene terephthalamide) that has no phenol derivative bonded to it, and has a common solvent with polyalkylene terephthalate. Therefore, it becomes possible to mix uniformly with polyalkylene terephthalate. And as a result,
This makes it possible to react with polyalkylene terephthalate. The poly(p-phenylene terephthalamide) represented by the above general formula used in the present invention is
It is necessary that either R ₁ or R ₂ be an alkyl group having 3 to 5 carbon atoms. Examples of the alkyl group having 3 to 5 carbon atoms include n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert
-butyl group, n-pentyl group, iso-pentyl group,
Mention may be made of the tert-pentyl group. Among these, tert-butyl group is particularly preferred. R ₁ and R ₂
If any of them are hydrogen or an alkyl group having 2 or less carbon atoms, the solubility in the solvent will be poor and it will be difficult to mix uniformly with the polyalkylene terephthalate. It is not clear why solubility improves only when either R ₁ or R ₂ is an alkyl group having 3 to 5 carbon atoms, but it is probably due to steric bulk at the ortho or meta position. It is presumed that the bonding of the substituent with the above disorder disrupts the symmetry of the molecule and inhibits crystallinity, thereby improving solubility. 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) used in the present invention, that is, n in the above-mentioned general formula, needs to be 2 or more than 2. When n is 1, it is not preferable because the physical properties (strength, elastic modulus, etc.) of the resulting aromatic polyesteramide are hardly improved. Also, n is
When it is larger than 20, the effect of the terminal phenol derivative is relatively reduced, and there is a tendency for the solubility in the solvent to decrease. Therefore, it is usually preferable for n to be in the range of 2 to 20. In addition, the degree of polymerization n mentioned here means an average degree of polymerization. The poly(p-phenylene terephthalamide) used in the present invention includes terephthalic acid chloride, p-phenylene diamine and the general formula It can be produced by reacting a terephthalic acid chloride monophenol derivative ester 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. Salts such as lithium chloride and calcium chloride may be added to these solvents in an amount of about 0.5 to 8% by weight. 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 rapidly and quantitatively at the same time as the raw materials are mixed, and the poly(p-phenylene terephthalamide) of the present invention is obtained. The reaction temperature is preferably lower than room temperature, and suitably around 0°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, triethylamine, tri-n-propylamine, tri-n-butylamine, N-
- Tertiary amines such as ethylpiperidine and N-ethylmorpholine may be added. 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 carried out almost quantitatively, it is preferable to use terephthalic acid chloride and p-phenylenediamine in approximately equimolar ratios. The obtained poly(p-phenylene terephthalamide) is
Although it has a small amount of carboxyl end and amine end, more than 90% of it has phenol derivative end, so it can be uniformly dispersed in polyester resin without purification. The polyalkylene terephthalate used in the present invention is a polyester obtained from terephthalic acid or its ester-forming derivative and a linear aliphatic diol, and has alkylene groups such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate. has 2 to 4 carbon atoms. Among these, polyethylene terephthalate is particularly preferred since it provides an aromatic polyester amide with particularly high strength and high elastic modulus. These polyalkylene terephthalates may have up to 20 mol% of the terephthalic acid component and/or diol component replaced with other dicarboxylic acids or diols. Examples of such dicarboxylic acids include isophthalic acid, phthalic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, etc., and examples of diols include neopentyl glycol, 1.4- Cyclohexanediol, 1,4-cyclohexanedimethanol, diethylene glycol,
Examples include polyethylene glycol. The molecular weight of the polyalkylene terephthalate used is not particularly limited, but if the molecular weight becomes too large, the number of terminal groups will decrease, and the amount of poly(p-phenylene terephthalamide) that can be copolymerized will be limited. Usually, it is suitable that the intrinsic viscosity measured with a 1:1 mixed solution of phenol/tetrachloroethane at 25° C. is about 0.2 to 0.6. A method for uniformly mixing polyalkylene terephthalate and the aforementioned poly(p-phenylene terephthalamide) is to dissolve each of the polyalkylene terephthalate and poly(p-phenylene terephthalamide) in an appropriate solvent, and then It is convenient to mix these solutions to form a homogeneous solution. The solvents used at this time include dimethyl sulfoxide for polyalkylene terephthalate, and dimethylacetamide, dimethylformamide, N-methylpyrrolidone, hexamethylphosphoramide, etc. for poly(p-phenylene terephthalamide). can be given. It is also possible to simultaneously dissolve polyalkylene terephthalate and poly(p-phenylene terephthalamide) in a single or mixed solution of the above-mentioned solvents, but the above-mentioned method is better in that the polymer can be dissolved more efficiently. Are better. Since the copolymerization reaction is carried out in a solid state, it is necessary to separate the polymer from the polymer solution in order to use it for the reaction.
Methods for separating a polymer from a solution include contacting the solution with a non-solvent for the polymer (water, methanol, etc.) to solidify the polymer and separating it from the solvent, and cooling the solution to precipitate the polymer and separating it from the solvent. and a method of removing the solvent by evaporation. It is desirable that the polymer separated from the solution be subjected to the reaction after removing as much of the solvent as possible by operations such as washing and drying. The copolymerization reaction of poly(p-phenylene terephthalamide) and polyalkylene terephthalate is carried out almost quantitatively, so by adjusting the ratio of poly(p-phenylene terephthalamide) and polyalkylene terephthalate to be subjected to the reaction. , a polyesteramide with any copolymerization composition can be produced. However, poly(p-
If the ratio of (phenylene terephthalamide) to polyalkylene terephthalate is less than 1% by weight, the effect of improving strength and elastic modulus will not be sufficient, and if it exceeds 20% by weight, the moldability of polyesteramide tends to decrease. Usually, it is appropriate to use 1 to 20 parts by weight of poly(p-phenylene terephthalamide) per 100 parts by weight of polyalkylene terephthalate. In the present invention, polyalkylene terephthalate and poly(p-phenylene terephthalamide)
The copolymerization reaction with is carried out under reduced pressure or normal pressure, similarly to the solid phase polymerization of polyester. When the reaction is carried out under normal pressure, it is preferably carried out in an inert gas stream. The reaction temperature is preferably a temperature similar to that used for solid-state polymerization of polyester, and usually a temperature in the vicinity of the melting point of polyalkylene terephthalate to a temperature 50° C. lower than the melting point is suitable. Even more preferred is a temperature range from the melting point of polyalkylene terephthalate to 30°C lower than the melting point. The above-mentioned reaction is usually carried out in the presence of a catalyst (such as antimony, titanium, zinc compounds, etc.) used in the polycondensation reaction of polyalkylene terephthalate, but since such catalysts generally remain in polyalkylene terephthalate, , the reaction proceeds satisfactorily even without the addition of a new melting medium. However, if necessary, such catalysts can also be added during the reaction. When polyalkylene terephthalate and poly(p-phenylene terephthalamide) are reacted as described above, a transesterification reaction occurs between the phenol derivative ester end of poly(p-phenylene terephthalamide) and the hydroxyl end of polyalkylene terephthalate. Polycondensation occurs and polyesteramide is produced. The obtained polyesteramide is a block copolymer in which polyalkylene terephthalate segments and poly(p-phenylene terephthalamide) segments are alternately bonded, and the length of each segment is determined by the length of the polyalkylene terephthalate and poly(p-phenylene terephthalamide) segments used as raw materials. It depends on the molecular weight of (p-phenylene terephthalamide).
Furthermore, the number of repetitions of each segment can be adjusted to suit the purpose by controlling the raw materials, reaction conditions, and the like. Polyalkylene terephthalate and poly(p-phenylene terephthalamide) are A polyester amide is produced through a polycondensation reaction. In the produced polyesteramide, the polyalkylene terephthalate segment consists of the following formula (), and the poly(p-phenylene terephthalamide) segment consists of the formula (). (Here, l is an integer of 2 to 6, and m is a number corresponding to the average degree of polymerization of polyalkylene terephthalate having an intrinsic viscosity of 1 or more, preferably 0.2 to 0.6.) Then, the segment of formula () is replaced by A, formula()
When the segment of is represented by B, polyester amide has a molecular structure like...A-B-A-B... Phenol derivative liberated by transesterification reaction

[Synthesis of poly(p-phenylene terephthalamide)]

N-
Add 400ml of methylpyrrolidone and cool 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. After separating the precipitate using a glass filter, the precipitate was washed several times with water and vacuum dried. The terminal carboxyl group and amino group of the obtained compound were quantified by neutralization titration, and as shown in Table 1, the carboxyl group was 60 to 60%.
240 μeq/g, and amino groups were 0 to 20 μeq/g. Since the theoretical total number of terminal groups is approximately 1500 μeq/g, it is considered that most of the polymers have phenol derivatives bonded to their terminal 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] Examples 1 to 5, Comparative Examples 1 to 2 Phenol/tetrachloroethane 1:1 at 25°C
50 g of polyethylene terephthalate with an intrinsic viscosity of 0.35 dl/g measured as a mixed liquid was dissolved in 500 ml of dimethyl sulfoxide by heating to 170°C, and this solution was dissolved.
Cool to 150℃. A solution in which 2.5 g of poly(p-phenylene terephthalamide) obtained in Reference Examples 1 to 7 was dissolved in 50 ml of N.methylpyrrolidone was added to the polyethylene terephthalate solution and mixed with stirring. The mixed solutions using poly(p-phenylene terephthalamide) of Reference Examples 1 to 5 were brownish and transparent solutions. Furthermore, when the materials obtained in Reference Examples 6 and 7 were used, the solubility in N-methylpyrrolidone was poor, and it was difficult to make a uniform solution with polyethylene terephthalate, resulting in a solution mixed with precipitates. It was hot. These solutions were immediately added to a large amount of water to precipitate the polymer. The precipitated polymer was filtered, washed with water, and vacuum dried at 120° C. for 48 hours to obtain polyethylene terephthalate in which poly(p-phenylene terephthalamide) was uniformly mixed. The obtained polymer was subjected to solid phase polycondensation at 240° C. under a vacuum of 0.1 mmHg or less for 8 hours to obtain a light brown polymer. Among the obtained polymers, Reference Examples 1 to 5
The products using the poly(p-phenylene terephthalamide) obtained in (Examples 1 to 5) were uniformly dissolved in trifluoroacetic acid, indicating that the poly(p-phenylene terephthalamide) was copolymerized. was confirmed. However, in the case of Comparative Examples 1 and 2 in which the materials obtained in Reference Examples 6 and 7 were used, when dissolved in trifluoroacetic acid, a large amount of insoluble matter, which appeared to be poly(p-phenylene terephthalamide), was generated. Therefore, it is considered that the copolymerization reaction has hardly progressed. In addition, the polymers obtained in Examples 1 to 5 were dissolved in trifluoroacetic acid,
When the NMR spectrum was measured, poly(p-
(phenylene terephthalamide) substituent attached to the terminal phenyl group (i.e. R ₁ , R ₂ or R ₃ )
The amount of absorption was extremely small and could only be seen as a trace. In addition, the infrared absorption spectrum was calculated using KBr.
When measured using the tablet method, N-H was found near 3300 cm ^-1.
Absorption based on vibration was observed. Therefore, the obtained polymer is considered to be a polyesteramide obtained by copolymerizing poly(p-phenylene terephthalamide) and polyethylene terephthalate. In addition, the intrinsic viscosity of the polymers obtained in Examples 1 to 5 in trifluoroacetic acid at 25°C is 0.85 to 0.98 dl/g.
The melting point was approximately 262°C. Example 6 Same as Reference Example 1 except that 20.3 g of terephthalic acid chloride, 10.1 g of o-tert-butylphenol, and 7.20 g of p-phenylenediamine were used.
Poly(p-phenylene terephthalamide) in which R ₁ is a tert-butyl group and R ₂ and R ₃ are hydrogen was synthesized.
The obtained polymer has a carboxyl group of 190μeq/
g, amino groups were 30 μeq/g, and the degree of polymerization was 2 as determined by NMR analysis. 5.0 g of the obtained poly(p-phenylene terephthalamide) and 50 g of polyethylene terephthalate having an intrinsic viscosity of 0.35 dl/g were mixed uniformly in the same manner as in Example 1, and precipitated to form poly(p-phenylene terephthalamide). Polyethylene terephthalate was obtained in which polyethylene terephthalate was uniformly mixed. This was subjected to solid phase polycondensation at 240° C. under a vacuum of 0.1 mmHg or less for 8 hours to obtain a light brown polymer. The obtained polymer was uniformly dissolved in trifluoroacetic acid, and the intrinsic viscosity at 25℃ was
It was 0.91 dl/g. Further, when an NMR spectrum was measured, almost no absorption of tert-butyl group was observed, and when an infrared absorption spectrum was measured, an absorption based on N-H vibration was observed around 3300 cm ^-1 . The melting point was 261°C. Example 7 Put 400 ml of dimethylacetamide into the separable flask from 1, add 10 g of anhydrous lithium chloride, dissolve at room temperature, and then cool to 0°C. o-
tert-butylphenol 0.60g and triethylamine
Add 5.4ml and then add terephthalic acid chloride.
16.24g of p-phenylenediamine was added and reacted for 15 minutes, then 20ml of α-vicolin was added, and 8.44g of finely powdered p-phenylenediamine was added at once and reacted for 3 hours at 0°C to form poly(p-phenyleneterephthalamide). ) was synthesized. The reaction solution was added to a large amount of water, and the resulting precipitate was separated and dried. of the obtained polymer
The degree of polymerization determined from the intrinsic viscosity in a 96% concentrated sulfuric acid solution (25°C) was 18. 0.5 g of the obtained polymer was dissolved in 100 ml of N-methylpyrrolidone containing 4% by weight of anhydrous lithium chloride, and 50 g of polyethylene terephthalate with an intrinsic viscosity (phenol/tetrachloroethane 1:1 mixture, 25°C) of 0.51 dl/g was dissolved. dimethyl sulfoxide 500
ml solution at 150°C. The mixed solution was a brownish transparent solution. This solution was added to a large amount of water while hot to precipitate the polymer to obtain polyethylene terephthalate in which poly(p-phenylene terephthalamide) was uniformly mixed.
This was subjected to solid phase polycondensation at 240° C. under a vacuum of 0.1 mmHg or less for 8 hours to obtain a light brown polymer. The obtained polymer was uniformly dissolved in trifluoroacetic acid and had an intrinsic viscosity of 1.01 dl/g. Also,
When the NMR spectrum was measured, almost no absorption of tert-butyl group was observed, and when the infrared absorption spectrum was measured, N-H was observed near 3300 cm ^-1 .
Absorption based on vibration was observed. The melting point was 263°C. Example 8 1 g of poly(p-phenylene terephthalamide) obtained in Reference Example 1 was dissolved in 50 ml of N-methylpyrrolidone, and the intrinsic viscosity in a phenol/tetrachloroethane (1:1) mixed solution at 25°C was determined. is 0.55dl/
of polybutylene terephthalate dissolved in 500 ml of dimethyl sulfoxide at 150°C. The resulting mixed solution was a brownish transparent solution. This solution was added to a large amount of water while hot to precipitate the polymer to obtain polybutylene terephthalate in which poly(p-phenylene terephthalamide) was uniformly dispersed. After drying this in vacuum, solid phase polymerization was carried out at 200° C. and under reduced pressure of 0.1 mmHg or less for 8 hours. The obtained polymer was uniformly dissolved in trifluoroacetic acid, and as a result of NMR analysis, tert
-Butyl group absorption was not observed, and when the infrared absorption spectrum was measured, absorption based on N-H vibration was observed near 3300 cm ^-1 . Also, the intrinsic viscosity is
The amount was 1.1 dl/g, and the melting point was 227°C.

Claims (1)

[Claims] 1. Polyalkylene terephthalate solution and general formula [In the formula, either R ₁ or R ₂ has 3 to 5 carbon atoms
is an alkyl group, and the other is hydrogen. Also,
R ₃ represents hydrogen, a lower alkyl group or a lower alkoxy group, and n represents 2 or a number of 2 or more. ] After uniformly mixing the aromatic polyester amide with a poly(p-phenylene terephthalamide) solution represented by Manufacturing method.