JPS62100527A - Fluorine-containing copolyester - Google Patents

Abstract

PURPOSE:A polyester that is composed of two kinds of specific structure units, thus being melt-formable, having good flame, retardancy, chemical resistance and wear resistance and moreover, showing outstanding mechanical properties and heat resistance. CONSTITUTION:A fluorine-containing copolyester is composed of 30-90mol% of formula I units and 70-10mol% of formula II units. The copolymer is preferably prepared using 4-hydroxybenzoic acid and 4-hydroxy-2,3,5,6- tetrafluorobenzoic acid by deacetoxylation. The ratio of I/II is preferably 40/60-90/10, and the polymerization degree is over 100.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention can be melt-molded at temperatures below 450°C, has excellent N flammability, chemical resistance, and abrasion resistance, as well as excellent mechanical properties and heat resistance. The present invention relates to a fluorine-containing copolyester having properties.

<Prior Art> In recent years, fluorine chemicals have been attracting attention in the field of fine chemicals. Among these, although fluoropolymers are aliphatic polymers, they have unique properties such as heat resistance, chemical resistance, oil repellency, water repellency, and non-stick properties. Taking advantage of its properties, its use as highly functional resins and films has recently expanded considerably.

However, among these fluoropolymers, for example, polytetrafluoroethylene has an abnormally high melt viscosity, which makes it impossible to apply the melt processing method applied to general plastics.

For this reason, the basic processing method used in powder metallurgy is to compress polytetrafluoroethylene powder once and heat it above its melting point to fuse the polytetrafluoroethylene particles. .

Therefore, only simple molded products such as sheets, rods, and pipes could be obtained.

In response, melt-moldable aliphatic fluoropolymers such as polyvinylidene fluoride and tetrafluoroethylene-hexafluoroethylene copolymers have been developed to improve the moldability and mechanical strength of polytetrafluoroethylene. (Plastics J Shark (2)
, 20. (I985)').

However, although these melt-moldable aliphatic fluoropolymers can be molded by a general melting method, since they are aliphatic polymers, they still have 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, which requires special metal materials, which is a major problem in the processing process.

Such problems of heat resistance or low mechanical properties are caused by having an aliphatic skeleton in the main chain, and it has been essentially impossible to solve these problems.

On the other hand, for aromatic fluorine-containing polymers, 4-oxy-2,3,5, which is a fluorine-substituted product of 4-oxybenzoic acid,
, Synthesis of poly-oxy-2,3,5,6-titrafluorobenzoate 1 using 6-tetrafluorobenzoic acid, Kobunshi Papers 39.8.531-534
(I982).

However, it is stated that the polymer described in this document has poor heat resistance even though it is an aromatic fluorine-containing polymer.

Further, a homopolyester consisting only of the structural unit 10o-Q-eO- is known as "Econol" (manufactured by Sumitomo Chemical Co., Ltd.).

<Problems to be solved by the invention> The present inventors have discovered that this poly-4-oxy-2,3,5,6
- The cause of the poor heat resistance of titrafluoropenzoate was investigated, and the reason was found to be due to the starting material 4-oxy-2
, 3,5,6-tetrafluorobenzoic acid was found to have inappropriate acetylation reaction conditions, and if the acetylation reaction was carried out under specific conditions, highly pure 4-acetoxy-2,3,
5,6-tetrafluorobenzoic acid or its oligomer can be obtained, and by polymerizing this raw material, poly-4-oxy-2,3,5, which has extremely good heat resistance and can be melt molded, can be obtained.
, 6-tetatrafluoropenzoate.

However, it has been found that this polymer is not necessarily sufficient in terms of mechanical properties.

Furthermore, "Econol" (manufactured by Sumitomo Chemical Co., Ltd.) has an extremely high melting point, making it impossible to perform normal melt molding, and its mechanical properties were also insufficient.

Means for Solving the Problems> Therefore, the present inventors developed poly-4-oxy-2,3,5,6
-We conducted intensive studies to solve the problem of heat resistance of titrafluorobenzoate and at the same time improve the mechanical properties of this polymer.

As a result, polyesters with the following structural formula (I)a, which can be melt-molded at relatively low temperatures and have good heat resistance during extrusion molding, that is, have excellent mechanical properties with extremely low generation of metal-corrosive gas, The present invention has been accomplished by discovering a fluorine-containing confluence polyester consisting of (II), characterized in that the units (I> account for 30 to 90 mol% of the total, and the units (II) account for 7O-IOEL% of the total). reached.

F -E-0-G-CO→・・・・・・・・・(I)F "As mentioned above, the homopolyester consisting only of the @ structural unit (I) is different from the copolyester of the present invention. and its mechanical properties are inadequate.

Furthermore, since the homopolyester "Econol" consisting only of the structural unit (II) has an extremely high melting point, ordinary melt molding is impossible, and its mechanical properties are also insufficient. Copolymerized polyester has good moldability, and it is also possible to obtain molded products with excellent mechanical properties and heat resistance.

The ratio (I>/(II)) of units (I) and (II) in this copolyester is from 30/70 to 90/10, but is particularly preferably from 40/60 to 90/10.

That is, when (I)/(II) is less than 30/70, the moldability and mechanical properties of the obtained molded product are poor,
When (I)/(II) is larger than 90/10, the mechanical properties are not good, which is not preferable.

The intermolecularity of this copolymerized polyester can be measured by hydrolyzing the polymer and then quantifying the amount of acetic acid produced using Gas Chroma 1 to Graphie, and the degree of polymerization is preferably 100 or more. That is, if the degree of polymerization is less than 100, the mechanical properties of the resulting molded article tend to be insufficient.

The fluorine-containing polyester of the present invention can be produced by the acetic acid depolymerization method using an acylated product of 4-oxybenzoic acid and 4-oxy-2,3,5,6-tetrafluorobenzoic acid as follows.

That is, 4 to 5 moles of acetic anhydride to 1 mole of 4-oxy-2,3,5,6-tetrafluorobenzoic acid, and 0.05 to 0.05 moles of acetic acid as a catalyst. Add 5 molar amount or 1X10'''3 to 1X10-2 molar amount of sodium acetate, reaction temperature 120-130°C, preferably 125-130'C.
4-acetoxy-2°3,5,6-tetrafluorobenzoic acid obtained by reacting for 5 to 20 hours, preferably 10 to 20 hours (point 124 to 125°C) or its oligomer derivative (melting point 130 to 205°C) ℃) and a predetermined amount of 4-acetoxybenzoic acid obtained from 4-oxybenzoic acid in a conventional manner at 150 to 300℃ for 1 to 10 hours in an inert gas atmosphere such as nitrogen or argon, and then
300-350℃ at the same time as high vacuum for 100 minutes
Polycondensation is completed by raising the temperature to 180°C to 210°C and reacting for 1 to 50 hours, or at 180 to 210°C under high vacuum for 1 to 5 hours.
A method of in-phase polymerization for 0 hours is preferred.

The above-mentioned literature (Kobunshi Paper Collection 39.8.531-534
(I9B2)), one of the starting materials, 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid, has low purity, and moreover, it is suddenly polymerized under a vacuum of 60 mN0, so in this case, 4-acetoxy-2,3,5,6
- The sublimation of tetrafluorobenzoic acid is severe and the yield of the polymer is low, and the copolymerization ratio changes, making it impossible to obtain the desired composition. Only the polymerization method of the present invention can achieve good heat resistance with little sublimation. It is possible to create a polymer with a copolymer composition for a specific purpose.

In addition, a method in which 4-oxy-2,3,5,6-tetrafluorobenzoic acid and 4-oxybenzoic acid are reacted with a desired amount of diphenyl carbonate to form a phenyl ester, and then produced by a dephenol polycondensation reaction. However, the above-mentioned polymerization method using acetic acid removal is more preferable.

In addition, typical catalysts used in polycondensation reactions include metal compounds such as stannous acetate, tetrabutyl titanate, sodium acetate, potassium acetate, antimony trioxide, and metallic magnesium. It is valid.

In addition, when polycondensing the aromatic polyester of the present invention, 3-chloro-4 is added to the above structural units (I> and (II>).
-oxybenzoic acid, 3-methyl-4-oxybenzoic acid,
3-Mehexy-4-oxybenzoic acid, 3-7enyl-4-oxybenzoic acid, 3,5-dichloro-4-oxybenzoic acid, 3,5-dimethyl-4-oxybenzoic acid, 3.
5-dimethoxy-4-oxybenzoic acid, m-oxybenzoic acid, 2. Aromatic oxycarboxylic acids such as tooxynaphthoic acid and 2,7-oxynaphthoic acid may be further copolymerized within a small proportion that does not impair the object of the present invention.

In addition, terephthalic acid, isophthalic acid, 4,4゛- diphenyldicarboxylic acid, 2,6
-naphthalene dicarboxylic acid, 1゜2-bis(phe7noxy)ethane-4,4゛-dicarboxylic acid, 1,2-bis(
A dicarboxylic acid component such as 2-chlorophenoxy)ethane-4,4-dicarboxylic acid, 4,4'-cica J levoxidinoenyl ether, etc. is roughly co-extended with the diol component in an equimolar but very small proportion. Polymerization is also possible.

The fluorine-containing copolymerized polyester of the present invention thus obtained has a low melting point of 248 to 298°C, and can be used for extrusion molding, injection molding,
It can be subjected to ordinary melt molding such as compression molding and blow molding, and can be processed into fibers, films, three-dimensional molded products, containers, hoses, etc.

During molding, reinforcing agents such as glass fiber, carbon fiber, and asbestos, fillers, nucleating agents, pigments, antioxidants, stabilizers, plasticizers, lubricants, mold release agents, and hardening agents are added to the aromatic polyester of the present invention during molding. Additives such as refueling agents and other polymers can be added to impart desired properties to the molded article.

Examples of this polymer include aliphatic fluoropolymers such as polytetrafluoroethylene and commercially available aromatic polymers.
Econol” [manufactured by Sumitomo Chemical Co., Ltd.], “U Polymer” [
In addition to PEE (manufactured by Unitika Co., Ltd.) and "PEE" (manufactured by ICI), there are various polysulfones, polyethersulfones, polyphenylene sulfides, and polyethylene terephthalate and polybutylene terephthalate. Also included are various types of Thermo 1 to Robic liquid crystalline polyesters.

By the way, the strength of the thus obtained molded article can be increased by heat treatment, and in many cases, the elastic modulus can also be increased.

This heat treatment can be carried out by heat treating the molded article in an inert atmosphere (e.g. nitrogen, argon, helium or water vapor) or in an oxygen-containing atmosphere (e.g. air) at a temperature below the melting point of the polymer. It may or may not be stressful, and can be done within a few minutes to several days.

The fluorine-containing copolymerized polyester of the present invention thus formed has 4
It is possible to obtain a fluorine-containing copolymer that can be melt-molded at temperatures below 50° C. and has excellent flame retardancy, chemical resistance, and abrasion resistance, as well as excellent heat resistance and mechanical properties.

<Example> The present invention will be described in detail below with reference to Examples.

Example 1 In a fourth flask equipped with a cooling tube, 1-oxy-2,
3,5,6-tetrafluorobenzoic acid 21 (0.1 mol), acetic anhydride 40.89 (0.4 mol), acetic acid 2.13
was charged, the internal temperature was maintained at 125-130'C, and the reaction was carried out under a nitrogen atmosphere for 15 hours. Reaction 1 was poured into water, excess acetic anhydride was hydrolyzed to acetic acid, and the precipitate was filtered. The precipitate was purified by recrystallization twice with benzene and ligroin.

The melting point of the obtained monomer was 124-125°C, and the IR
At 1830 cm', a new absorption due to the acetyl group not seen in the raw material 4-oxybenzoic acid was observed, indicating that it was 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid. confirmed.

7.56 g of synthesized 4-acetoxy-2,3,5゜6-tetrafluorobenzoic acid (0,3X10
-1 mol), 4-acetoxybenzoic acid 12.69 (0,
7×10'mol) was charged and acetic acid depolymerization was carried out under the following conditions.

First, the mixture was reacted for 3 hours at 150 to 250'C in a nitrogen atmosphere, and then the pressure was reduced to 1.0 mHg or less at 250'C for 130 minutes, and at the same time, the reaction was carried out at 250 to 350°C for 10 hours at 1.0 mH or less. The elemental analysis results of this polymer are shown in Table 1, and showed good agreement with the theoretical values corresponding to the general formula (not shown in I>) and the theoretical structural formula.

In addition, the degree of polymerization determined from vinegar Ml after hydrolyzing the polymer was 310 (number average molecule 14/1.000).
III/n=3/7) Table 1 However, oxygen・0(%)-100(%)-C(%)-F(
%) - old %).

In addition, when we measured the infrared absorption spectrum, we found that it was 1735c.
Absorption due to carbonyl of poly(P-oxybenzoate) of unpurchased fluorine observed in m-' and 179
Poly(P-oxy-2,3,5□6-titrafluoropenzoate), a fluorine-substituted product found in
The absorption due to the carbonyl of 1743 cm-
It was confirmed that 1 overlapped with each other and formed a copolymer.

This polymer was measured using a differential scanning calorimeter (PerkinElmer model ■).
Melting point: 298°C, heat of crystal fusion: 12.5c
al/s. Further, this polymer was subjected to spinning using a Koka-type flow tester at a spinning temperature of 330° C. and a spinneret hole diameter of 0.5 φ to obtain a spun yarn of 0.2 sφ. The melt viscosity was 18,000 poise at a sliding speed of 103 (sec-1).

Further, when the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a sample length of 50 m and a tensile speed of 10 m/min, it was found to have a high strength of 5.61/d).

The elastic modulus was measured using Rheopybron DDV-n-EA (manufactured by Toyo Bold Fin Co., Ltd.) at a frequency of 110H2, a back-warming rate of 2°C/min, and a distance between chucks of 40m ().
It was found that the elastic modulus at 30°C was as high as 4°2 GPa.

Example 2 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid 12.6 synthesized in the same manner as in Example 1 was used as a polymerization tester.
Example 1
The polycondensation reaction was carried out in the same manner as above.

The elemental analysis results of this polymer are shown in Table 1, and showed good agreement with the theoretical values corresponding to the theoretical structural formula shown in general formula (II>).

You can also use vinegar to hydrolyze polymers! The degree of polymerization determined from ffi was 290 (number average molecular weight 45,000).

(Wl/n=515) Table ■However, oxygen・0(%)=100(%)-C(%)-F(
%)-11(%).

This polymer was measured using a differential scanning calorimeter (PerkinElmer N type).
The melting point was 263°C and the heat of crystal fusion was 0.
It was 8 cal/y. In addition, this polymer was subjected to a Koka type flow tester at a spinning temperature of 280°C and a diameter of 0.5 mm per spinneret.
Spinning was performed at sφ to obtain a spun yarn of O02#φ.

The melt viscosity is 8 at a shear rate of 103 (5ec-1).
It was 000 voices.

Further, when the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a trial run of 50 m and a tensile speed of 10 m/min, it was found to have a high strength of 12.5 (g/d).

In addition, the elastic modulus measured by the same method as in Example 1 using Rheopybron DDV-n-EA (manufactured by Toyo Baldwin) was found to be a high value of 9.8 GPa.

Example 3 4-Hydroxy-2 was placed in a four-bottle flask equipped with a cooling tube.
,3,5,6-tetrafluorobenzoic acid 21SJ(0,
1 mol), 40.89 (0.4 mol) acetic anhydride, and 0.02 HJ of sodium acetate, and brought the internal temperature to 125-130.
The temperature was maintained at 0.degree. C., and the reaction was carried out for 15 hours under a nitrogen atmosphere. After the reaction, the mixture was poured into water to hydrolyze excess acetic anhydride into acetic acid, and the precipitate was filtered. The precipitate was purified by recrystallization twice with benzene and ligroin.

The resulting product is largely insoluble in chloroform;
When the melting point was measured, it was found to be an oligomer containing nanatsuma with a melting point in the range of 130 to 200'C.

IR showed a new absorption at 1798 cm-' caused by an acetyl group that was not seen in the raw material 4-hydroxybenzoic acid, and the target 4-acetoxy-2°3.5.6
- It was confirmed that the oligomer contained tetrafluorobenzoic acid.

Oligomer of 4-acetoxy-2,3,5゜6-tetrafluorobenzoic acid synthesized in the polymerization tester (average molecular weight determined from elemental analysis and GPC analysis results is approximately 630, oligomer mainly composed of trimer) 10.
5y (0.5 x 10" 1 mol in terms of monomer), 4
-Acetoxybenzoin! ! 29.0g (0.5X10-X
mol) and polymerized in the same manner as in Example 1 to perform a polycondensation reaction.

The results of elemental analysis of this polymer are shown in Table 2, and showed good agreement with the theoretical values corresponding to the theoretical structural formula shown in general formula (■).

Further, the degree of polymerization determined from the amount of acetic acid after hydrolyzing the polymer was 270 (number average molecule 1a2ooo).

"F (Flow/n=515) Table ■However, oxygen・O(%)-100(%)-C(%)-F(
%)-11(%).

This polymer was measured using a differential scanning calorimeter (PerkinElmer model ■).
Melting point measured at 261°C1 Heat of crystal fusion 0.
It was 8 cal/y. In addition, this polymer was subjected to a Koka type flow tester at a spinning temperature of 280°C and a diameter of 0.5 mm per spinneret.
Spinning was carried out at 8φ to obtain a spun yarn with a diameter of 0.2 InMφ.

The melt viscosity is 7 at a shear rate of 103 (5ec-1).
It was 000 poise.

Further, when the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a sample length of 50 m and a tensile speed of 10 #/min, it was found to have a high strength of 11.9 (0/d).

In addition, the elastic modulus measured by the same method as in Example 1 using Rheopybron DDV-n-EA (manufactured by Toyo Baldwin) was found to be a high value of 3.7 GPa.

Example 4 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid 22.6 synthesized in the same manner as in Example 1 was used as a polymerization tester.
8 g (0.9 x 10" 1 mole) and 4-acetoxybenzoic!l!1.89 (o, vxlo - 1 mole) were charged and polymerized in the same manner as in Example 1 to carry out a polycondensation reaction.

The elemental analysis results of this polymer are shown in Table 1V, and showed good agreement with the theoretical values corresponding to the theoretical structural formula shown in general formula (IV).

Further, the degree of polymerization determined from vinegar II by hydrolyzing the polymer was 320 (number average molecular weight 59,000).

(rrt /n = 9.' 1) 1st v table However, oxygen・0(%)=100(%)-C(%)-F(
%)-H(%).

This polymer was measured using a differential scanning calorimeter (Pergin-Elmer model ■).
Torakoro melting point measured at 248°C1 Heat of crystal fusion 3.
It was 2 cal/bi. In addition, this polymer was subjected to a Koka type flow tester at a spinning temperature of 280°C and a diameter of 1 spinneret hole of 0.
Spinning was performed with 5#Iφ to obtain a spun yarn of 0.2 sφ.

Note that the melt viscosity is 11 at a shear rate of 103 (5ec-1).
It was 000 voices.

Further, when the spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a test length of 50 m and a tensile speed of 10 m/min, it was found to have a high strength of 7.6 (g/d).

Incidentally, the elastic modulus measured using Rheopybron DDV-II-EA (manufactured by Toyo Baldwin Co., Ltd.) in the same manner as in Example 1 was found to be a high value of 4.8 GPa.

Comparative Example 1 4-acetoxybenzoic acid 18. Og (
When the polycondensation reaction was carried out in the same manner as in Example 1, the temperature reached 250°C during the temperature rise.
The polymer solidified at and remained solidified up to 11,350°C.

The degree of polymerization determined from the amount of acetic acid after hydrolyzing this polymer was 3.
60 (number average molecule ψ43000).

This polymer was measured using a differential scanning calorimeter (PerkinElmer model ■).
However, no melting point peak was obtained.

I also attempted to spin this polymer using a high-speed flow tester, but I was unable to spin it at all.

Comparative Example 2 5.0 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid was IC-synthesized in the same manner as in Example 1 in a test tube for polymerization.
49 (0.2×10 −1 mole) and 14.4 g (0.8×10” mole) of 4-acetoxybenzoic acid were charged and polymerized in the same manner as in Example 1 to perform a polycondensation reaction.

The degree of polymerization determined from the amount of acetic acid after hydrolyzing the obtained polymer was 330 (number average molecule 144,000).

This polymer was measured using a differential scanning calorimeter (PerkinElmer model ■).
When measured, the melting point was 305°C1 crystal heat of fusion! 2.
It was 5caf/g. In addition, this polymer was subjected to a Koka type flow tester at a spinning temperature of 350°C and a spinneret hole diameter of 0.51.
Spinning with M1φ 0.2.1+! ! A spun yarn of lφ was obtained.

Note that the melt viscosity is 2 at a shear rate of 103 (sec').
It had 3000 voices.

In addition, when the above spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a sample length of 50 sx and a tensile speed of 10 m/min, the result was 3.8 (g/d) compared to the result obtained in the example. The strength was low.

The elastic modulus measured using Rheopyblon DDV-[-EA (manufactured by Toyo Baldwin) in the same manner as in Example 1 was 2.5 GPa, which, like the strength, is a lower value than the results obtained in Example. Comparative Example 3: 4-acetoxy-2,3,5,6-tetrafluorobenzoic acid M25°2 synthesized in the same manner as in Example 1 was placed in a polymerization test tube.
y (I, 0x10-' mol) was charged and polymerized in the same manner as in Example 1 to perform a polycondensation reaction.

The degree of polymerization determined from the amount of acetic acid after hydrolyzing the obtained polymer was 360 (number average molecule ff 169,000).

In addition, when we measured the infrared absorption spectrum, we found that it was 1796c.
Carbonyl absorption was observed at m', confirming the @formula.

This polymer was measured with a differential scanning calorimeter (PerkinElmer type II) and found to have a melting point of 252°C and a heat of crystal fusion of m3.
It was 5 cal/g. In addition, this polymer was subjected to a Koka flow tester at a spinning temperature of 330°C and a diameter of 0.5 mm per spinneret.
Spinning was carried out at sφ to obtain a spun yarn of 0.2 #φ).

Note that the melt viscosity is 1 at a shear rate of 103 (sec').
It was 5000 poise.

In addition, when the above spun yarn was measured using Tensilon 100 (manufactured by Toyo Baldwin Co., Ltd.) at a sample length of 50 #2 and a tensile speed of 10 m/min, the result was 2.9 (g/d), which was obtained in the example. The strength was lower compared to that of the previous one.

By the way, the elastic modulus measured in the same manner as in Example 1 using Rheovibe DD Sea [-EA (manufactured by Toyo Baldwin) was 1.9 GPa, and the strength was similar to the results obtained in Example 1. It was found that the value was relatively low.

<Effects of the Invention> The present invention provides a fluorine-containing material that can be melt-molded at temperatures below 450'C, has excellent flame retardancy, chemical resistance, and abrasion resistance, and also has excellent mechanical properties and heat resistance. It is now possible to obtain copolymerized polyester.

Claims (1)

[Claims] Consisting of the following structural formulas (I) and (II>, the unit (I)
is 30 to 90 mol% of the total, and unit (II) is 70 to 90 mol% of the total
A fluorine-containing copolymerized polyester characterized by accounting for 10 mol%. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II)