JPS63273637A - Fluorine-containing copolymerized aromatic polyester - Google Patents

Abstract

PURPOSE:To provide a fluorine-containing copolymerized aromatic polyester composed of two specific kinds of constituent units, melt-moldable at <=400 deg.C and having excellent flame-retardancy, chemical resistance, abrasion resistance, mold fluidity and mechanical characteristics. CONSTITUTION:4-Hydroxy-2,3,5,6-tetrafluorobenzoic acid is copolymerized with a specific monomer to obtain the objective fluorine-containing copolymerized aromatic polyester composed of 95-5mol.% (preferably 90-10mol.%) constituent unit of formula I and 5-95mol.% (preferably 10-90mol.%) constituent unit of formula II.

Description

[Detailed description of the invention] <Industrial application field> The present invention can be melt-molded at temperatures below 400°C, has excellent flame retardancy, chemical resistance, and abrasion resistance, and has excellent molding fluidity. This invention relates to a fluorine-containing aromatic copolyester that has both mechanical properties and mechanical properties.

<Prior Art> In recent years, fluorine chemicals have been attracting attention in the field of fine chemicals. Among them, fluoropolymers such as polytetrafluoroethylene are aliphatic, but have excellent heat resistance and chemical resistance, as well as unique properties such as water repellency, oil resistance, and non-adhesion. Taking advantage of these properties, it has a wide range of uses as high-performance resins and films.

However, among these fluoropolymers, for example, polytetrafluoroethylene forms a transparent gel at 327°C, but its melt viscosity is extremely high, so it has the disadvantage that the melt processing method used for processing most plastics cannot be applied. have.

For this reason, polytetrafluoroethylene is molded using methods similar to powder metallurgy. That is, the basic processing method is to compress polytetrafluoroethylene powder once under high pressure and then heat it above its melting point to fuse it. Therefore, it was impossible to make fine molded products, and only simple molded products such as sheets, rods, and pipes could be obtained.

In contrast, polyvinyfluoropolymer has been developed for the purpose of improving the moldability, mechanical properties, etc. of polytetrafluoroethylene.

On the other hand, as an aromatic fluorine-containing polymer, poly-4-oxy-2,3,5,6-titrafluoropenzoate polymerized using 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid is used. is Polymer Papers 39.8.531-5
34 (1982).

<Problems to be Solved by the Invention> However, melt moldable aliphatic fluorine compounds such as the polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc. The polymer does not have sufficient molding fluidity, and since it is an aliphatic polymer, there are still problems with heat resistance during extrusion molding. That is, hydrogen fluoride generated by thermal decomposition during extrusion molding significantly corrodes metal materials such as screws, and a special metal material is required to lick it, which is a major problem in the processing process.

The above-mentioned document also describes the problem of heat resistance and the fact that fluoropenzoate has poor heat resistance despite being an aromatic fluorine-containing polymer.

The present inventors discovered that this poly-4-oxy-2,3,5,6
- As a result of examining the cause of the poor heat resistance of titrafluoropenzoate, it was found that when produced by the method described in the above-mentioned literature, only a monomer with low purity is obtained, and the heat resistance of the polymer obtained from it is poor. It has been found. Furthermore, it was also found that the polymerization conditions were not appropriate and the polymer yield was low.

After further investigation, they discovered a method to obtain highly pure monomers. Although the polymer obtained by polymerizing this monomer had good heat resistance, it was not satisfactory in terms of mechanical properties such as strength and elasticity, and its molding fluidity was insufficient due to its high melt viscosity. Understood.

Therefore, the present invention has developed poly-4-oxy-2,3,5,6-titrafluoropenzoate using bodroxy 2.3, which has good mechanical properties such as strength and elasticity and good molding fluidity without impairing the heat resistance. , 5. An excellent machine that has good molding fluidity at relatively low temperatures by copolymerizing 6-tetrafluorobenzoic acid with a specific monomer, and does not generate metal-corrosive gas during extrusion molding. The present invention was achieved by discovering that a fluorine-containing copolymerized polyester having the following characteristics can be obtained.

That is, the present invention provides a fluorine-containing aromatic compound consisting of the following structural formulas (I> and (n), in which the structural unit (I) accounts for 95 to 5 mol% of the total, and the structural unit (II) accounts for 5 to 95 mol% of the total. The present invention provides a group copolymerized polyester.

F In the fluorine-containing aromatic copolymer polyester of the present invention, it is preferable that the structural unit represented by (I> is 10 to 90 mol%, and the structural unit represented by (I[) is 90 to 10 mol%).

If the ratio of the structural unit (I> to the whole) is less than 5 mol % or more than 95 mol %, molding fluidity will be poor, and neither is practical.

There are no particular limitations on the method for producing the fluorine-containing aromatic copolyester of the present invention. For example, 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid is reacted with phenyl acetate using hydrogen chloride as a catalyst to synthesize phenyl 4-hydroxy-2,3,5,6-tetrafluorobenzoate. and a method of producing the polyester by polycondensation with phenyl 4-hydroxy-3-phenylbenzoate synthesized separately by a dephenolization method;
Examples include a method of producing by an acetic acid depolymerization method using an acetylated product of hydroxy-2,3,5,6-tetrafluorobenzoic acid and an acetylated product of 4-hydroxy-3-phenylbenzoic acid.

A particularly preferred method is the latter method of producing by acetic acid depolymerization method.

That is, per mole of 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid, 4 to 5 molar equivalents of acetic anhydride and 1xio-3 to 1x10- of sodium acetate as a catalyst.
4-acetoxy-2,3,5,6-tetrafluorobenzoic acid (M point 130 ~131°C> and 4 in the usual manner.
-4- obtained from hydroxy-3-phenylbenzoic acid
After reacting a predetermined amount of acetoxy-3-phenylbenzoic acid at 150'C for 1 to 3 hours in an inert gas atmosphere such as nitrogen or argon, the temperature was raised to 250 to 350'C, and the temperature was increased to 1 to 350'C.
A method is preferably used in which the reaction is carried out for 4 hours, followed by applying high vacuum to complete the polycondensation reaction.

In the above method, if the reaction at 150°C is insufficient, decarboxylation will occur from 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid when the temperature is subsequently raised to 250-350°C. , it is preferable to allow sufficient reaction.

The degree of polymerization of the fluorine-containing copolyester obtained by the above-mentioned acetic acid removal polymerization method is preferably such that the polymer is hydrolyzed.

Although it is not necessary to add a catalyst to the polycondensation reaction by removing acetic acid, catalysts such as sodium acetate, potassium acetate, stannous acetate, tetrabutyl titanate, antimony trioxide, and metallic magnesium can be used.

Furthermore, when polycondensing the edible fluoroaromatic copolyester of the present invention, in addition to the structural units represented by formulas (I) and (I), as long as the amount is small enough not to impair the purpose of the present invention. Hydroquinone, resorcinol, 4,4°-dihydroxydiphenyl ether, chlorohydroquinone, methylhydroquinone, phenylhydroquinone, 2,6-
Diol components such as dihydroxynaphthalene and 2,7-hydroxynaphthalene as well as terephthalic acid, isophthalic acid, 4゜4゛-diphenylcarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis(phenoxy) Ethane-4,4'-dicarboxylic acid, 1,2-bis(2-chlorophenoxy)ethane-4,4°-dicarboxylic acid, 4
It is also possible to copolymerize a small amount of ,4'-dicarboxy.

The fluorine-containing aromatic copolyester of the present invention has a melting point of 1
Due to its low temperature of 50 to 330℃ and low melt viscosity, it can be easily processed into fibers, films, three-dimensional molded products, container hoses, etc. by conventional melt molding methods such as extrusion molding, injection molding, compression molding, and blow molding. Can be formed into

Further, the fluorine-containing aromatic copolymer polyester of the present invention may be used with reinforcing materials such as glass fiber, carbon fiber, asbestos, etc.
By melting and mixing additives and polymers such as fillers such as talc and mica, nucleating agents, pigments, dyes, antioxidants, stabilizers, plasticizers, lubricants, mold release agents, and flame retardants, various characteristics can be imparted.

Furthermore, the strength of molded articles made from the fluorine-containing aromatic copolyester of the present invention can be increased by heat treatment, and the modulus of elasticity can also be increased in many cases. This heat treatment can be performed on the molded article using an inert gas such as nitrogen, argon, helium, or hydrogen.

<Example> Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 4-Hydroxy-2,
21 g (0.1 mol) of 3,5,6-tetrafluorobenzoic acid, 40.8 g (0.4 mol) of acetic anhydride, 0.02 g of sodium acetate. was charged, and the reaction was carried out at an internal temperature of 120'C under a nitrogen atmosphere for 9 hours. Pour the reaction mixture into water, hydrolyze excess acetic anhydride, dissolve the acetic acid in the system in water, and filter out the precipitate. The precipitate was purified by recrystallization twice with benzene and ligroin. The melting point of the product is 130-131°C, and the infrared absorption spectrum and proton NMR indicate that it is 4-acetoxy-2,3,5,6-
It was confirmed that it was tetrafluorobenzoic acid.

Next, after a separate synthesis reaction with 7.56 g (0.03 mol) of synthetic 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid, the temperature was raised to 250°C and the reaction was further carried out for 2 hours. After raising the temperature to the original state of 320° C. over 1 hour, pressure reduction was started and the pressure was reduced to 1 mmH1;l or less in 30 minutes, and polymerization was continued for another 30 minutes. The results of elemental analysis of this polymer are shown in Table 1, and this polymer has the following structural formula (I[I
) was in good agreement with the theoretical value calculated from

Further, the degree of polymerization determined from the amount of acetic acid after hydrolyzing this polymer was 280 (number average molecular fi 54,000).

Table 1 However, oxygen 0 (X) = 100 (%) - 〇 (X) - F (X
)-H (%).

When this polymer was observed under a polarizing microscope on a hot stage, it began to flow at 172° C. and exhibited optical anisotropy when abrasion strain was applied.

In addition, this polymer was subjected to a Koka type flow tester, and 26
Spinning was carried out at 0°C with a spinneret hole diameter of 0.3 mmφ and 0.08
A spun yarn with a diameter of 0 mm was obtained. Note that the melt viscosity is the shear rate of 10
3 (sec-') Ivy at 2700 poise.

Furthermore, the above-mentioned spun yarn was processed using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) with a paper length of 50 mm and a tensile strength of 101.
When measured under the condition of 11IIIZ minutes: 10.2
(o/d) I really understand how strong it is.

In addition, this spun yarn was used as Rheopylon DDV-II-E.
Using type A (manufactured by Toyo Baldwin), the frequency is 1iot.
When the elastic modulus was measured at IZ, a temperature increase rate of 2°C/min, and a distance between chucks of 40 nwn, the elastic modulus at 30°C was 34.
4g (0.02 mol) and 4-acetoxy-3-phenyl ben Table 2 However, oxygen 0 (%) = 100 (%) - C (%) - F (%)
-H (%).

When this polymer was observed on a hot stage under a polarizing microscope, it began to flow at 163° C., and optical anisotropy was observed when strain was gradually applied.

In addition, this polymer was subjected to a Koka type flow tester, and 260
℃, spinneret hole diameter 0.3■φ, 0.085-φ
A spun yarn was obtained. Note that the melt viscosity is measured at a sliding speed of 103 (S
cc') and 2300 voices.

Further, the elastic modulus of the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a paper length of 50 m5 and a tensile speed of 10 ma, and the elastic modulus was as high as 30.6 GPa.

Example 3 2.52° (0.01 mol) of 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid and 4-acetoxy-3-phenylbenzoic acid synthesized in the same manner as in Example 1 were placed in a polymerization test tube. 7.68 g (0.03 mol) of acid was charged and acetic acid depolymerization was carried out in the same manner as in Example 1. The results of elemental analysis of this polymer are shown in Table 3, and the following structural formula (V)
It was in good agreement with the theoretical value calculated from the above.

Further, the degree of polymerization determined from the amount of acetic acid after hydrolyzing this polymer was 240 (number average molecular fi 47,000).

(m/n=25/75) Table 3 However, oxygen O (%) = 100 (%) - C (%) - H (χ
) - F (%).

When this polymer was observed under a polarizing microscope on a hot stage, it showed no optical anisotropy when it started flowing at 186°C and was subjected to shear strain.

Further, this polymer was subjected to a Koka-type flow tester, and spinning was performed at a spinning temperature of 260°C and a spinneret hole diameter of 0.3 mmφ.
A spun yarn with a diameter of 09 mm was obtained. Note that the melt viscosity is the sliding speed 1
03 (sec-') r3900 bois.

When the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a paper length of 50 mm and a tensile speed of 10 m/min, it was found to have a high strength of 6.2 (g/d).

Comparative Example 1 4-acedoxy 2,3,5.6-tetrafluorobenzoic acid 12-6 synthesized in the same manner as in Example 1 in a polymerization test tube
g (0.05 mol) and subjected to acetic acid depolymerization in the same manner as in Example 1.

The degree of polymerization determined from the amount of acetic acid by hydrolyzing the obtained polymer was 290 (number average molecular fi 57,000).

When this polymer was observed under a polarizing microscope on a hot stage, it began to flow at 258°C and exhibited optical anisotropy when abrasion strain was applied.

In addition, this polymer was subjected to a Koka type flow tester, and 330
℃, spinneret hole diameter 0.5mmφ, 0.18nw
A spun yarn of nφ was obtained. Note that the melt viscosity is the shear rate of 103
The viscosity was 18,000 poise (sec'), which was higher than the results obtained in the example.

In addition, the above spun yarn was processed using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a paper length of 50 mcn and a tensile speed of 10 mm.
When measured in terms of Z minute, the strength was 2.7 (g/d), which was lower than the results obtained in Examples.

In addition, Rheopaiburon DDV-II-EA type (Toyo Bo Comparative Example 2 4-acetoxy-3-phenylbenzoic acid 12.8 g (
0.05 mol) was placed in a polymerization test tube, and de-acetic acid polymerization was carried out under the following conditions.

First, the reaction was carried out at 220°C for 30 minutes in a nitrogen atmosphere, then the reaction was carried out for 20 minutes at 280°C over 1 hour, and then the temperature was increased to 300°C.
After raising the temperature to , pressure reduction was started, and the size was reduced to 1 mm and 11 g or less in 30 minutes, and polymerization was continued for another 30 minutes. The polymerization degree determined from the amount of acetic acid by hydrolyzing the obtained polymer was 170 (
The number average molecular weight was 33,000).

This polymer was subjected to a high-speed flow tester at 400℃,
Spinning was attempted with a spinneret hole diameter of 0.5 ma, but the fluidity was poor and the material was brittle, so spinning was not possible.

<Effects of the Invention> The present invention provides a fluorine-containing aromatic compound that can be melt-molded at temperatures below 400°C and has excellent flame retardancy, chemical resistance, and abrasion resistance, as well as excellent molding fluidity and mechanical properties. Polymerized polyester can now be obtained.

Claims (1)

[Claims] Consisting of the following structural formulas (I) and (II), the structural unit (
A fluorine-containing aromatic copolymer polyester in which I) accounts for 95 to 5 mol% of the total, and the structural unit (II) accounts for 5 to 95 mol% of the total. ▲There are mathematical formulas, chemical formulas, tables, etc.▼……(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼………………(II)