JPS6050819B2 - Polyester manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing polyester.

More specifically, the present invention relates to an improved method for producing a highly polymerized copolyester having a high Young's modulus and high tenacity and comprising an aromatic dicarboxylic acid component, an aromatic or aliphatic dicarboxylic acid component, and an aromatic dioxy compound component. Polyethylene terephthalate is widely used industrially because of its excellent mechanical performance, but it cannot be said to be sufficient in terms of Young's modulus and strength depending on the application.

Therefore, it is desired to develop polymers with high Young's modulus and high strength. In recent years, it has been discovered that molded products with high Young's modulus and high strength can be obtained by melt molding certain wholly aromatic polyesters (see Japanese Patent Publication No. 47-4787). As a method, for example, p-oxybenzoic acid and phenyl acetate are reacted using a hydrochloric acid catalyst, and p-oxybenzoic acid, diphenyl isophthalate, and hydroquinone are reacted, and the molar ratio of diphenyl isophthalate and hydroquinone is approximately 1.
A method has been proposed in which polycondensation is carried out at a ratio of 1:1.
However, this method requires the use of highly corrosive compounds such as acetic acid and hydrochloric acid during the reaction, and therefore does not require a reactor made of corrosion-resistant materials, and is suitable for polycondensation reactions. This process requires a long time and is not suitable as an industrial method for producing wholly aromatic polyester. On the other hand, as a method for producing a wholly aromatic polyester containing p-oxybenzoic acid as a third component, for example, terephthalic acid and isophthalic acid are esterified together with p-oxybenzoic acid by adding phenol.
A known method is to then add an aromatic dioxy compound such as hydroquinone to this reaction compound and carry out polycondensation, but in this case, when the reaction temperature is increased in an attempt to shorten the esterification reaction time, m-oxybenzoic acid is The disadvantage is that polyester of the desired composition cannot be obtained, probably because thermal decomposition occurs.

The present inventor has conducted extensive research into an industrially advantageous method for producing polyester that does not have these drawbacks, and has finally arrived at the method of the present invention.

That is, in the present invention, when producing a polyester consisting of a bifunctional carboxylic acid component consisting of an aromatic oxycarboxylic acid, an aromatic dicarboxylic acid and/or an alicyclic dicarboxylic acid, and a diol component of an aromatic dioxy compound, the aromatic Esterification reaction rate of group oxycarboxylic acid and aromatic monooxy compound and/or aromatic dioxy compound 70 to 95%
The reaction mixture (4) itself, aromatic dicarboxylic acid and/or alicyclic dicarboxylic acid, and aromatic monooxy compound and/or aromatic dioxy compound are esterified to an esterification reaction rate of 70 to 95%. This is a method for producing polyester, which comprises mixing and heating the reaction mixture (B) itself and, if necessary, an aromatic dioxy compound (C) to cause polycondensation.

In the method of the present invention, the aromatic oxycarboxylic acid includes:
For example, in addition to p-oxybenzoic acid and m-oxybenzoic acid, 3-chloro-4-oxybenzoic acid, 3-methyl-4-oxybenzoic acid, 3-methoxy-4-oxybenzoic acid, 4-chloro-3-oxybenzoic acid Examples include oxybenzoic acids whose nucleus is substituted with a halogen atom, an alkyl group, or an alkoxy group such as the following.

Among these, p-oxybenzoic acid is particularly preferred. In the method of the present invention, the aromatic dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, 5-methylterephthalic acid, 4-methylisophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl dicarboxylic acid, and diphenyl dicarboxylic acid. rusulfonedicarboxylic acid, diphenooxyethanedicarboxylic acid, 5-chloroterephthalic acid,
Examples include 4-chloroisophthalic acid.

Examples of alicyclic dicarboxylic acids include cyclohexane-1,4-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid,
3-dicarboxylic acid, decalin-2,6-dicarboxylic acid,
Decalin-2,7-dicarboxylic acid, dicyclohexy-4,4''-dicarboxylic acid, etc. can be mentioned. Among these aromatic dicarboxylic acids or alicyclic dicarboxylic acids, terephthalic acid, isophthalic acid, diphenooxyethane dicarboxylic acid, etc. Acid or cyclohexane-1,4-dicarboxylic acid is particularly preferred. In the method of the present invention, examples of the aromatic dioxy compound include compounds represented by the following formula.

HO-Ar [(0'+-MAr'3-NOH]
In the formula, Ar represents a divalent aromatic nucleus, and M and n are the numbers O or 1. The above aromatic nucleus (Ar) includes a substituted or unsubstituted aromatic nucleus, and more specifically, a substituted or unsubstituted aromatic nucleus. Examples include a benzene nucleus or a naphthalene nucleus.

Specific aromatic dioxy compounds include, for example, hydroquinone, resorcinol, methylhydronoquinone, chlorhydroquinone, methoxyhydroquinone, ethoxyhydroquinone, chlorresorcinol, methylresorcinol, ethoxyresorcinol, 2,6-dihydroxynaphthalene, 2, 7-dihydroxynaphthalene, 4,4-
Dioxy biphenyl, 3,3″-dioxybiphenyl,
3,3″-dimethyl-4,4″-dioxybiphenyl,
4,4″-dioxydiphenyl ether, 3,3″-dioxydiphenyl ether, 3,3″-dichloro-4,
Examples include 4''-diphenyl ether. Among these, hydroquinone and 4,4''-dioxydiphenyl are particularly preferred.The molar ratio of the aromatic oxycarboxylic acid component and the aromatic dicarboxylic acid and/or alicyclic dicarboxylic acid component in the copolyester preferred in the present invention is ,1
The content of the diol component in the preferred copolyester is in the range from 0:100 to 100:10, particularly preferably in the range from 25:100 to 100:25; The amount is approximately equimolar to the content of the cyclic dicarboxylic acid component.

The esterification reaction mixture (4) used as the aromatic oxycarboxylic acid component in the production of the above copolyester itself refers to the esterification reaction mixture (4) used as the aromatic oxycarboxylic acid and the aromatic monooxy compound and/or the aromatic dioxy compound at an esterification reaction rate of 70. It is the reaction mixture itself (hereinafter referred to as mixture A) that has undergone an esterification reaction to ~95%,
These aromatic monooxy compounds are phenol, cresol, p-ethylphenol, p-butylphenol, p-
- An aromatic monooxy compound substituted or unsubstituted with a lower alkyl group or a halogen atom, such as chlorophenol, m-chlorophenol, β-naphthol, etc.

Here, the term 1 above means that the obtained reaction mixture is not subjected to any treatment such as purification treatment. In addition, the esterification reaction mixture (B) itself refers to esterification of the aromatic dicarboxylic acid and/or alicyclic dicarboxylic acid and the aromatic monooxy compound and/or aromatic dioxy compound to an esterification reaction rate of 70 to 95%. This is the reaction mixture itself (hereinafter referred to as B mixture). Here, the term 1 above means that the obtained reaction mixture is not subjected to any treatment such as purification treatment. In the esterification reaction when producing mixture A or mixture B, an aromatic monooxy compound and/or Or, an aromatic monooxy compound and/or an aromatic dioxy compound is used so that the hydroxyl group of the aromatic dioxy compound is 1 times the mole or more, preferably 1.1 to 4 times the mole, particularly preferably 1.2 to 2 times the mole. I will do it. In this case, since the aromatic dioxy compound can carry out the esterification reaction in a relatively short time using a smaller amount than the aromatic monooxy compound, the temperature is preferably 240 to 360°C. Further, the upper limit of the more preferable esterification temperature in producing mixture B may be changed depending on the type of difunctional carboxylic acid used. This upper limit temperature is 340°C when using an alicyclic dicarboxylic acid, and 340°C when using an aromatic dicarboxylic acid.
The temperature is 60°C. The esterification reaction time is usually 1 hour to 1 hour.

The esterification reaction is continued until the esterification reaction rate is 70-95%, preferably 84-95%. If the esterification reaction rate is less than 70%, the next polymerization reaction will not proceed sufficiently and it will be difficult to obtain a high polymerization degree polyester, and if it is higher than 95%, the esterification reaction time will be too long, and the polyester This is not preferable because the coloring becomes intense. Here, the esterification reaction rate is determined from the following formula. In the esterification reaction to obtain mixture A or mixture B, a catalyst is not necessarily required, but preferably a catalyst is used.

Examples of catalysts include titanium, tin, lead, antimony,
Examples include metals such as bismuth, cerium, lanthanum, lithium, sodium, potassium, and zinc, and compounds containing these metals. More specifically, for example, titanium tetrabutoxide, titanyl oxalate, stannous acetate, lead oxide, lead acetate, antimony, antimony trioxide, antimony pentoxide, bismuth trioxide, cerium acetate, lanthanum oxide, lithium acetate, Examples include sodium metal, potassium benzoate, and zinc acetate.
The amount of these catalysts used is 0.005 to 0.5 mol%, preferably 0.005 to 0.5 mol%, based on the carboxylic acid component such as the aromatic oxycarboxylic acid, aromatic dicarboxylic acid, and alicyclic dicarboxylic acid.
．． 01 to 0.1 mol%. In the method of the present invention, polyester is produced by adding the aromatic dioxy compound as a diol component to the mixtures A and B, if necessary, and subjecting them to polycondensation under heating.

Here, 2° is preferably used. The esterification reaction temperature is 150 to 330° C1 when producing mixture A.
Preferably 180-300°C, particularly preferably 240-300°C
280°C, and 230°C when producing B mixture.
The amount Y (number of moles) of the aromatic dioxy compound required to be added before polycondensation at ~400°C is expressed by the following formula (1), where X.

．． ．． YO represents the number of moles of the aromatic dicarboxylic acid and/or alicyclic dicarboxylic acid and the number of moles of the aromatic dioxy compound used during the esterification reaction, and Y is zero or more. ] Particularly preferably, it is represented by the following formula (2).

[However, X.

．． ．． Y is the same as defined above] If the amount used is too small, it will be difficult to obtain a polyester with a sufficiently high degree of polymerization even if the next polycondensation time is lengthened, and if it is too large, the polymerization time will be shortened. It becomes long, which is not desirable. l
In the method of the present invention, polyester is produced by distilling off aromatic dioxy compounds and/or aromatic monooxy compounds in excess of the esterification reaction product out of the reaction system.

This polymerization reaction is preferably carried out at a C1 temperature of 250 to 400°C, particularly preferably 270 to 360°C, and a reaction pressure of 760°C to 360°C.
0.001TrrInHf1 preferably 10-0.01
TIrInHg. The reaction is usually carried out in the molten state,
It may be carried out in a solid phase if necessary. In addition, in the production of the above polyester, a small proportion of a dioxy compound represented by the following formula may be added to the reaction mixture after the esterification reaction, if necessary, to remove excess aromatic dioxy compound and/or aromatic monooxy compound from the reaction system. A copolyester can also be obtained by carrying out a polymerization reaction while distilling off. [However, in the formula, Ar is a divalent aromatic nucleus, R1 and R2 are lower alkyl groups having 1 to 6 carbon atoms, and may be bonded to each other. ] Specific examples of the dioxy compound represented by the above formula include 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane,
Examples include 1,1-bis(4-hydroxyphenyl)cyclohexane.

According to the method of the present invention, highly corrosive compounds such as hydrochloric acid and acetic acid are not produced as by-products during the polymerization reaction, and industrially useful polyester with a high degree of polymerization can be produced at low cost using inexpensive raw materials. can be manufactured.

The method of the present invention will be explained below with reference to Examples. Incidentally, "part" in the examples means 1 part by weight.

In addition, the amount of free carboxyl groups was calculated using Konics' j method (M
akrO,sMOlecnlarlCheml26,2
26 (1958)), and the amount of ester groups was determined by saponifying the sample with an alcoholic solution of caustic soda and then back titrating the excess alkali with sulfuric acid. Example 1c (
1) Production of an esterification reaction mixture of isophthalic acid and methylhydroquinone. 3,318 parts of isophthalic acid, 37 parts of methylhydroquinone, and 2 parts of stannous acetate were placed in an esterification pot and heated at 300°C for 6 hours in a nitrogen atmosphere.The water produced as a result of the esterification reaction was removed from the reaction system. It was removed.

The esterification rate of the resulting reaction mixture A was 93%. (2) Production of an esterification reaction mixture of p-oxybenzoic acid and methylhydroquinone. p-oxybenzoic acid 4
14 parts, 27 parts of methylhydroquinone, and 4 parts of stannous acetate were placed in an esterification pot and heated at 260 to 270°C for 6 hours under a nitrogen atmosphere to remove the water produced as a result of the esterification reaction. It was removed from the reaction system.

The esterification rate of the resulting reaction mixture B was 85%. (3) Production of copolyester The entire amount of reaction mixture A and reaction mixture B obtained in (1) and (2) above was put into a polymerization pot, and
After reacting at ~320°C for 3 minutes, the pressure of the reaction system was reduced to 60°C.
0.3T1 for 1 minute! IlHg and continue to 0.
Polymerization was carried out for 8 minutes under 2 to 0.3 μg of Hg.

The obtained polymer was dissolved in p-chlorophenol and 5
The intrinsic viscosity was determined to be 1.28 at 0° C. and a polymer concentration of 0.5 g/dl. On the other hand, the total amount of phenol that was produced as a by-product during the production of this copolyester was measured using gas chromatography for all distillates, and it was found to be 12% based on the p-oxybenzoic acid charged. p in polymer
- The results were consistent with the determination of the oxybenzoic acid content. Example 21) Production of an esterification reaction mixture of isophthalic acid and phenol.

3,318 parts of isophthalic acid, 65 parts of phenol, and 2 parts of stannous acetate were placed in an esterification kettle and heated to 280 to 290°C.
The mixture was pressurized to 6.5k9/Clt (gauge pressure) and heated for 8 hours to remove water produced as a result of the esterification reaction from the reaction system.

The esterification rate of reaction mixture A obtained here was 94%. 2) Production of an esterification reaction mixture of p-oxybenzoic acid and phenol.

41 parts of p-oxybenzoic acid, 9,870 parts of phenol, and 4 parts of stannous vinegar were placed in an esterification reaction vessel, and the pressure was increased to 6.5k9/Clt (gauge pressure) with nitrogen.
The mixture was heated to 0° C. for 8 hours, and water produced as a result of the esterification reaction was removed from the reaction system.

The esterification rate of the reaction mixture B obtained here was 84%. () Manufacture of copolyester.

The total amount of reaction mixture A and reaction mixture B obtained in (1) and (2) above and 6,600 parts of hydroquinone were placed in a polymerization pot, and the reaction mixture was allowed to react for 6 minutes at 300°C in a nitrogen stream, and then the pressure of the reaction system was reduced to 4. Polymerization was carried out for 90 minutes under a reduced pressure of 0.4 to 0.3 wrInHg.

The obtained polymer was dissolved in p-chlorophenol and 5
The intrinsic viscosity was determined to be 1.50 at a polymer concentration of 0.5 g/dl at 0°C. The decomposition rate of p-oxybenzoic acid in the above reaction was determined to be 15% by gas chromatographic analysis after decomposing the obtained polymer with methanol.

Example 3 (1) Production of an esterification reaction mixture of transcyclohexane-1,4-dicarboxylic acid and methylhydroquinone. transcyclohexane-1,4-dicarboxylic acid 3
437 parts, 372 parts of methylhydroquinone and 1st acetic acid
Add 2 parts of tin to an esterification kettle and heat at 280'C in a nitrogen stream.
The mixture was heated for 6 hours, and water produced as a result of the esterification reaction was removed from the reaction system.

The esterification rate of the reaction mixture A obtained here was 95%. ). ) Production of an esterification reaction mixture of P-oxybenzoic acid and methylhydroquinone. Example 1 (2
The esterification reaction was carried out in exactly the same manner as in the case of ) to obtain a reaction mixture B with an esterification rate of 85%.

]) Production of copolyester. The entire amount of reaction mixture A and reaction mixture B obtained in (1) and (2) above was put into a polymerization pot, and after 3 powders were subjected to a normal pressure reaction at 300°C in a nitrogen stream, 4 powders were added. The pressure of the reaction system was lowered to 0.5 TIrmHg, and the pressure was increased to 300'CO. 3-0.
Polymerization was carried out for 90 minutes under 5 liters of Hg.

The obtained polymer was dissolved in p-chlorophenol and 5
The intrinsic viscosity was determined to be 3.10 at 0° C. and a polymer concentration of 0.5 g/Dt. The total amount of phenol produced as a by-product during the production of the polymer was 13% based on the p-oxybenzoic acid charged.

Claims (1)

[Claims] 1. When producing a polyester consisting of a bifunctional carboxylic acid component consisting of an aromatic oxycarboxylic acid, an aromatic dicarboxylic acid and/or an alicyclic dicarboxylic acid, and a diol component of an aromatic dioxy compound, the aromatic oxycarboxylic acid and an aromatic monooxy compound and/or an aromatic dioxy compound to an esterification reaction rate of 70 to 95%, the reaction mixture (A) itself, an aromatic dicarboxylic acid and/or an alicyclic dicarboxylic acid, and an aromatic monooxy The reaction mixture (B) itself, which is obtained by reacting the compound and/or the aromatic dioxy compound to an esterification reaction rate of 70 to 95%, and if necessary, the aromatic dioxy compound (C) are mixed and heated to undergo polycondensation. A method for producing polyester, characterized by: