JP2552686B2 - Wholly aromatic polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a wholly aromatic polyester that can be suitably used as a material for paints, adhesives, fibers, films, molded articles and the like.

[Conventional technology]

Conventionally, dibasic acids such as terephthalic acid, isophthalic acid, carbonic acid, bisphenol A, bisphenol S, 4,4'-
A polycondensate with an aromatic dihydroxy compound such as dihydroxybiphenyl is referred to as polyarylate or wholly aromatic polyester, and has practical use as a material having melt anisotropy and excellent heat resistance and mechanical strength.

Further, as a material having higher heat resistance and excellent mechanical strength, poly (4-hydroxybenzoate), which is a polycondensation product of parahydroxybenzoic acid, and poly (1.4-, a polycondensation product of terephthalic acid and hydroquinone). Phenylene terephthalate) (Japanese Patent Publication No. 47-47870) and the like have been proposed. However, the polycondensate has poor moldability and has not yet been put to practical use.

[Problems to be solved by the invention]

In view of the above drawbacks, an object of the present invention is to provide a wholly aromatic polyester which has excellent heat resistance and mechanical strength, has melt anisotropy, and has good moldability.

[Means for solving problems]

The wholly aromatic polyester of the present invention is a polycondensate containing 2,2′-dicarboxybiphenyl and an aromatic dihydroxy compound as main components, and further, an aromatic hydroxycarboxylic acid as a component, if necessary. Melt viscosity measured by a tester at a temperature of 260 ° C. and a load of 100 kgf is 5000 to 12000 poise.

Examples of the aromatic dihydroxy compound include resorcin, 4-acetylresorcin, hydroquinone,
Chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone (2,5-dihydroxybiphenyl), methoxyhydroquinone, phenoxyhydroquinone, 4,4'-dihydroxybiphenyl, 3,3'-diphenyl-4,4'-dihydroxybiphenyl, 4 4,4'-dihydroxydiphenyl ether, 4,4'-
Dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 3,3'-diphenyl-4,4 '
-Dihydroxydiphenyl sulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, bisphenol A, 1,1'-di (4-hydroxyphenyl) cyclohexane, 1,2-bis (4-hydroxyphenoxy) ethane , 1,4-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, etc., to obtain a highly crystalline polycondensate, hydroquinone, 4,4′-
Dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxydiphenyl sulfide are preferably used.

Examples of the aromatic hydroxycarboxylic acid include salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 3-bromo-4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid. , 3-phenyl-4-hydroxybenzoic acid,
3-methoxy-4-hydroxybenzoic acid, 4-hydroxy-4'-carboxybiphenyl, 2-hydroxy-6
-Carboxynaphthalene and the like can be mentioned, and para-hydroxybenzoic acid and 4-hydroxy-4'-carboxybiphenyl are preferably used to obtain a highly crystalline polycondensate.

The wholly aromatic polyester of the present invention is a polycondensate containing 2,2′-dicarboxybiphenyl, an aromatic dihydroxy compound and, if necessary, an aromatic hydroxycarboxylic acid as a main constituent component. The 2,2'-dicarboxybiphenyl and aromatic dihydroxy compound are composed in a substantially equimolar ratio, and the aromatic hydroxycarboxylic acid can be composed in any amount. This is because the hydroxyl group and the carboxyl group undergo a condensation reaction to polymerize, and if either the hydroxyl group or the carboxyl group increases, it becomes difficult to obtain a high-molecular weight polycondensate.

Further, another aromatic dicarboxylic acid may be polycondensed in place of a part of 2,2'-dicarboxybiphenyl. Examples of such aromatic dicarboxylic acids include isophthalic acid, metal salts of 5-sulfoisophthalic acid, terephthalic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxylic acid. Carboxydiphenyl sulfide, 4,4'-dicarboxydiphenyl sulfone, 3,3'-dicarboxybenzophenone, 4,4'-
Examples include dicarboxybenzophenone, 1,2-bis (4-carboxyphenoxy) ethane, 1,4-dicarboxynaphthalene, and 2,6-dicarboxynaphthalene. To obtain a highly crystalline polycondensate, terephthalic acid , 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, 4,4'-dicarboxybenzophenone, 1,2-bis (4-carboxyphenoxy) ethane And 2,6-dicarboxynaphthalene are preferably used.

Although any method may be adopted as the method for producing the wholly aromatic polyester of the present invention, it is difficult to heat and condense each component as it is. Usually, it is preferable to carry out the polycondensation reaction while acetylating the hydroxy group of the constituents and then removing acetic acid. Acetylation proceeds easily only by heating the aromatic dihydroxy compound or aromatic dihydroxycarboxylic acid and acetic anhydride, and the hydroxy group is changed to an acetoxy group.

The polycondensation reaction can usually be carried out at a temperature of 200 ° C to 350 ° C. Particularly, a reaction catalyst is often not required, but a metal oxide, a metal hydroxide or a metal salt is used if necessary. Good results are obtained by first removing the acetic acid produced by the polycondensation reaction from the reaction system at normal pressure and finally at reduced pressure. The molecular weight of the polycondensate can be controlled by adjusting the molar ratio of the aromatic hydroxy compound and 2,2-dicarboxybiphenyl among the constituents, but this method is relatively low. It is effective when a polycondensate having a molecular weight is intended. In the range where the molecular weight is relatively high, a method of controlling the magnitude of the molecular weight by carrying out the reaction while taking the melt viscosity of the polycondensate as a guide is adopted. When higher molecular weight polycondensates are required, more polyfunctional components can be used, as long as the polycondensates do not gel. When the melt viscosity is adopted as a factor corresponding to the molecular weight of the polycondensate, the polycondensate of the present invention has a melt viscosity of 5000 to 12000 poise measured by a flow tester at a temperature of 260 ° C. and a load of 100 kgf.

When the above-mentioned highly crystalline component is incorporated into the constituents of the wholly aromatic polyester of the present invention, the polycondensate often exhibits melt anisotropy. Melt anisotropy can be confirmed by a polarization technique using an ordinary polarization microscope. More specifically, a test piece prepared to have a thickness of 1 mm or less is placed on a heating stage and heated at a temperature rising rate of 5 ° C./min in a nitrogen atmosphere to make the polarizers orthogonal to each other. It can be easily confirmed by observing with a polarizing microscope of 40 times or 100 times.

〔Example〕

 Next, examples of the present invention will be described.

Example 1 A hard glass three-necked flask with an internal volume of 100 ml equipped with a spiral stirrer, a thermometer, a gas blowing port, and a distillation port contained 2,2'-dicarboxybiphenyl 9.69 g (0.04 mol), 1 Charged with 7.77 g (0.04 mol) of 4,4-diacetoxybenzene and 7.21 g (0.04 mol) of paraacetoxybenzoic acid, put the flask in a bath of silicon oil and raise the temperature of the bath while blowing nitrogen gas from the gas blowing port. . When the temperature of the bath increased and the temperature of the contents reached about 240 ° C, the polycondensation reaction started, and the acetic acid produced started to distill from the distillation port. The temperature of the contents is raised to 300 ° C. in about 3 hours. 300
After 1 hour after the temperature reached to 0 ° C., the distillation port was connected to a vacuum vessel and the pressure inside the flask was gradually reduced to 1 Torr or less.
When the reaction was continued for 1 hour after the temperature became 1 Torr or less, the inside of the flask became an extremely viscous liquid, so the flask was pulled up from the bath and cooled. After the product was cooled and solidified, the flask was broken and taken out. The obtained product was a brown opaque wholly aromatic polyester, and had a melt anisotropy at 230 ° C. or higher when observed with a polarizing microscope.
The heat distortion temperature is 215 ° C (JIS K7207 compliant, 18.5kgf / c
m ² ), and the melt viscosity at 260 ° C. was 5000 poise. The melt viscosity was measured with a flow tester under a load of 100 kgf.

Example 2 Performed in Example 1 using 4.48 grams (0.02 moles) of 2,2'-dicarboxybiphenyl, 3.88 grams (0.02 moles) of 1,4-diacetoxybenzene and 7.21 grams (0.04 moles) of paraacetoxybenzoic acid. In the same manner as above, a pale brown opaque wholly aromatic polyester was obtained. Observation of the obtained polyester with a polarization microscope showed melt anisotropy at a temperature of 236 ° C. or higher, a heat distortion temperature of 223 ° C., and a melt viscosity at 260 ° C. of 10,000 poise.

Example 3 2,4'-dicarboxybiphenyl 4.84 grams (0.02 moles), 1,4-diacetoxybenzene 3.88 grams (0.02 moles) and paraacetoxybenzoic acid 10.81 grams (0.06 moles) were used in Example 1. A light brown opaque wholly aromatic polyester was obtained in the same manner as described above. The polyester obtained has a melt anisotropy at a temperature of 241 ° C. or higher when observed with a polarization microscope, and the heat distortion temperature is 230 ° C., 260
The melt viscosity at ° C was 12000 poise.

〔The invention's effect〕

The constitution of the wholly aromatic polyester of the present invention is as described above, and the aromatic dicarboxylic acid which is a constituent component of the polycondensate is
Since it is 2,2'-dicarboxybiphenyl, it has excellent heat resistance and mechanical strength, exhibits melt anisotropy, and has excellent moldability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C09K 19/38 9279-4H C09K 19/38 D01F 6/62 306 D01F 6/62 306U 308 308 6 / 84 303 6/84 303B

Claims (1)

(57) [Claims] 1. A polycondensate containing 2,2'-dicarboxybiphenyl, an aromatic dihydroxy compound and, if necessary, an aromatic hydroxycarboxylic acid as a main component.
A wholly aromatic polyester having a melt viscosity of 5000 to 12000 poise measured by a flow tester at a temperature of 260 ° C and a load of 100 kgf.