JPH01236232A - Resin having excellent heat resistance and exhibiting anisotropy when melted - Google Patents

Abstract

PURPOSE:To obtain the title resin excelling in heat resistance and easy processability, being good in hydrolysis resistance and exhibiting anisotropy when melted, by introducing specified amounts of three specified kinds of groups as essential structural components into the main chain. CONSTITUTION:A polyester resin having a hydroxybenzoic acid residue (A) of formula I (one having bonds in positions para to each other is desirable), a naphthalene group (B) of formula II and/or III and a group (C) of formula IV, wherein component A is present in an amount of 20-80mol.% based on the polymer, component B is present in an amount of 1-40mol.% based on the polymer, and component C is present in an amount of 1-40mol.% based on the polymer. As said naphthalene group of components B, naphthalenedicarboxylic acid residues of formulas V and VI and naphthalenediol residues of formulas VII and VIII are used. When compared with a conventional crystalline polymer, the above polyester resin is good in the balance between heat resistance and easy processability, good in hydrolysis resistance when heated and exhibits anisotropy when melted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyester resin that exhibits anisotropy when melted and has excellent heat resistance and mechanical properties.

[Conventional technology]

In recent years, various proposals have been made for liquid crystalline polymers that exhibit anisotropy when melted as thermoplastic resins that have both heat resistance and processability.

■Japanese Patent Publication No. 49-72393, ■Japanese Patent Application Publication No. 50-4322
No. 3, Japanese Patent Publication No. 54-50594, etc. are representative. All of these liquid crystalline polymers exhibit liquid crystallinity by introducing rigid monomers into their skeletons, and achieve high strength and easy processability.

[Problem that the invention seeks to solve]

On the other hand, as the applications of liquid crystalline polymers expand, higher performance is expected for such resins. That is, it is desired to provide a resin that has further solder resistance, heat resistance intended for high-temperature use, and easy processability for moldability.

Specifically, the processing conditions used, for example, the temperature range that allows normal molding, such as a melting point or flow temperature of about 350°C or less, and a heat distortion temperature used as an index of heat resistance, of about 200°C or more. Performance resins are desired.

This requires simultaneously satisfying the contradictory requirements of lowering the melting point or pouring point and increasing the heat distortion temperature. However, in the previous example, (2) satisfies the heat distortion temperature of 200°C or higher, but does not satisfy the molding temperature of 350°C or lower.

In addition, although the above-mentioned ■ and ■ satisfy the molding temperature of 350℃ or less, the heat distortion temperature of ■ is 100℃ or less, and ■ is 18
0°C, which is not within the desired range. Furthermore, since both use ester bonds as a bonding means, mechanical properties may be impaired under severe usage conditions such as use in a continuous hot water environment.

[Means for solving problems]

In view of the above problems, the present inventors conducted intensive research to obtain a thermoplastic resin that has heat resistance and processability within a suitable range, and also has excellent mechanical properties even in harsh environments. We have discovered that polyester using monomers can solve these problems in a well-balanced manner, leading to the present invention.

That is, the present invention has the following formula (I) in the main chain as an essential component.
The present invention provides a resin that exhibits anisotropy when melted and has excellent heat resistance, and is characterized by containing three types of groups represented by -(II[) in the following ranges.

0 20 to 80 mol% The bonding position of the hydroxybenzoic acid residue represented by the formula (1) is selected from one or both of the p-position and m-position, but the hydroxybenzoic acid residue at the p-position It is preferable that Furthermore, residues of acetoxybenzoic acid, which is a derivative of hydroxybenzoic acid, can also be used as such a component.

The naphthalene group represented by formula (n) includes naphthalene dicarboxylic acid residues (II-a) and (■-e), naphthalene diol residues (n-b) and (n-f), and hydroxynaphthoic acid residues. Group (■-c) and U (II-g)
, hydroxynaphthylamine residues (n-d) and (I
It is preferable to select one or more of Ih).

The bonding positions of naphthalene group (II) are 1, 4, and 1.6.
Selected from one or more of the following: 1st, 7th, 2nd, 6th, and 2.7th place. Preferably it is a bond at the 1.4-position, 2.6-position, or 2.7-position.

The group represented by formula (I), which is an essential component, is an essential component for achieving a favorable balance between heat resistance and processability, and specifically, 4,4'-dihydroxydiphenylketone or its derivatives. 4,4'-diacetoxydiphenylketone and the like are used.

According to the studies of the present inventors, the compound with this skeleton is twisted itself, and it imparts appropriate twist to the rigid skeleton of the polymer chain expressed in (I) and (n), resulting in heat resistance. and provides easy processability. To impart these properties (I
Ingredients II) are essential: hydroquinone, 4.
So-called rigid ones such as 4'-dihydroxybiphenyl are not preferred. Furthermore, bisphenol-type groups such as 4,4'-dihydroxydiphenylpropane, which have a similar skeleton, are also not suitable for exhibiting heat resistance.

It is completely unexpected and surprising that only the coexistence of the skeleton component (III) provides a good balance of heat resistance and processability, and also improves the hydrolysis resistance under heat.

(I) and (II) constituting the polymer compound of the present invention
.

Within the range where each component (III) exhibits liquid crystallinity,
It may have an appropriate substituent.

As a component unit in the polymer, (I) preferably does not exceed 80 mol%, and preferably does not fall below 20 mol%. If it exceeds 80 mol%, ease of processing is impaired, and if it is less than 20 mol%, it becomes difficult to develop liquid crystallinity.

(II) and (I[[) are each preferably in the range of 1 to 40 mol%. When each content exceeds 1 to 40 mol%, heat resistance, mechanical properties, and processability are impaired.

That is, when (1), (n), and (III) are out of their respective preferred ranges, the preferred balance of heat resistance, processability, and mechanical properties cannot be maintained.

Furthermore, the resin obtained in the present invention can contain, in addition to the above-mentioned essential constituents, a residue of a monomer capable of forming an ester or esteramide bond. They include phenylene skeleton, biphenylene skeleton, skeleton represented by the following general formula (TV), CH3CXneyCH2-, -C-, -0-, kan-, -3-, -
A typical example is one containing a 3[12-1CH3 alkylene skeleton or the like.

Specific examples of compounds containing a phenylene skeleton include terephthalic acid, isophthalic acid, hydroquinone, resolunol, and aminophenol.

Examples of those containing a biphenylene skeleton include 4.4''-dihydroxybiphenyl, 4.4'-dicarboxybiphenyl, and 4-hydroxy-4-carboxybiphenyl.

Those containing a skeleton represented by the general formula (rV) include 4
．． Examples include 4'-dihydroxydiphenylmethane, 4.4-dihydroxydiphenylpropane, 4.4''-dihydroxydiphenyl ether, 4.4°-dihydroxydiphenyl sulfide, and 4.4'-dihydroxydiphenyl sulfone.

Typical examples of those containing an alkylene skeleton include ethylene glycol, fluoropylene glycol, 1,4-butanediol, and the like.

It is preferable that the proportion of components other than these essential components does not exceed 40 mol% as component units in the polymer.

If it exceeds 40 mol%, it will deviate from the preferable range of heat resistance and processability. A more preferable range is 30 mol% or less.

The polymer obtained in the present invention has the above-mentioned constituent groups, and can be produced by a conventionally used general production method using a monomer having a functional group capable of reactions such as esterification and amidation.
For example, it can be produced by a melt polymerization method, a solution polymerization method, an interfacial polymerization method, a solid phase polymerization method, etc. The composition of each component constituting the polymer is achieved by using approximately the same proportions of the corresponding monomers.

Although the production proceeds substantially without a catalyst, conventionally known transesterification catalysts can be used.

Examples of transesterification catalysts include magnesium acetate, manganese acetate, stannous acetate, cobalt acetate, zinc acetate, germanium oxide, lead oxide, antimony trioxide, and bismuth trioxide. The amount of catalyst used is 0.01 to 0.2% by weight based on the total weight of monomers.

The polymer obtained in the present invention is insoluble in common solvents, but soluble in pentafluorophenol. Generally indicates logarithmic viscosity.

The polymer obtained according to the present invention exhibits anisotropy when melted.

The nature of the anisotropic melt phase can be confirmed by conventional polarization testing using crossed polarizers. More specifically, the anisotropic melt phase can be confirmed by using a Leitz polarization microscope and observing a sample placed on a Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere.

The polymer is optically anisotropic. That is, it transmits light when examined between orthogonal polarizers. If the sample is optically anisotropic, polarized light will pass through it even if it is at rest.

〔Effect of the invention〕

The polyester resin of the present invention has a better balance between heat resistance and ease of processing than conventional liquid crystal polymers, and also has good hydrolysis resistance, making it an industrially useful material that can be used in harsh environments. (It is phase resistant.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto. The liquid crystallinity of the obtained resin was confirmed using a Leitz polarization microscope, and the logarithmic viscosity was measured by dissolving it in pentafluorophenol. The melting point was measured with a differential scanning calorimeter, and those that could not be measured were determined by the flow initiation temperature under a polarizing microscope. Hydrolysis resistance was expressed as the retention rate of the logarithmic viscosity of a solvent-cast film after immersing it in boiling water for 120 hours with respect to the value before treatment.

The heat distortion temperature was measured in accordance with ASTM-0648 by preparing test pieces from the obtained polymer in a conventional manner.

Example 1 p-acetoxybenzoic acid 60 mol%, 2.6-dicarpoxynaphthalene 20 mol%, 4.4'-diacetoxydiphenylketone 20 mol%, 0.05 weight 1% acetic acid based on the total amount charged Potassium was charged into a reactor equipped with a nitrogen inlet tube and a distillation tube, and the mixture was heated to 260° C. for 1 hour under a nitrogen stream. While distilling acetic acid from the reactor, the reactor was heated to 260-300°C for 2 hours, then further heated to 300-360°C for 1 hour, and finally, after stopping the introduction of nitrogen, the inside of the reactor was depressurized, and the reactor was heated for 15 minutes. It was evacuated to 0.1 torr. The mixture was stirred at this temperature and pressure for 30 minutes.

The logarithmic viscosity, melting point, hydrolysis resistance, and heat distortion temperature of the obtained polymer were measured. The measured results are shown in Table 1.

Examples 2 to 7 Polymerization was carried out in the same manner as in Example 1 using the compositions shown in Table 1, and physical properties were measured in the same manner. The results are shown in Table 1.

Comparative Examples 1 to 9 With the compositions shown in Table 1, polymerization was carried out in the same manner as in Example 1 except for Comparative Examples 3.6.8. The physical properties were measured. The results are shown in Table 1.

Comparative Examples 3.6 and 8 had 260 to 300 at the time of polymerization.
Heat for 2 hours at 300-42°C for an additional hour.
Heated to 0°C. All other conditions were the same as in Example 1. Moreover, the polymer of Comparative Example 8 became insoluble and infusible during polymerization, and subsequent measurements could not be performed.

Claims (1)

[Claims] 1. The main chain contains the following formulas (I) to (III) as essential constituents:
A resin that exhibits anisotropy when melted and has excellent heat resistance, and is characterized by containing three types of groups shown in the following ranges. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) 20 to 80 mol% for the polymer ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and/or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) For the polymer 1 to 40 mol% ▲ Numerical formulas, chemical formulas, tables, etc. ▼ 1 to 40 mol% based on (III) polymer 2 Groups containing the group of formula (II) are of the following formulas (II-a) to (II-h
) The resin according to claim 1, which is one or more groups selected from the following. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-a) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-c) ▲ Mathematical formulas, chemical formulas, There are tables, etc. ▼ (II-d) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-f) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-g) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II-h)