JPH03172345A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition only slightly causing burr in injection molding, capable of molding a molded article having excellent dynamic and thermal performances and low shrinkage factor of molding, comprising a wholly aromatic polyester composed of a specific structural unit and an inorganic compound. CONSTITUTION:(A) 100 pts.wt. wholly aromatic polyester which is produced by using 4-hydroxybenzoic acid, terephthalic acid, 4,4'-dihydroxydiphenyl ether, acetic anhydride, etc., as raw materials and has 40-75mol% unit shown by formula I, 12.5-30mol% unit shown by formula II and 12.5-30mol% unit shown by formula III wherein the units shown by formula II and formula III are equal in number of mols, preferably thermotropic liquid crystal polyester which comprises 45-86mol% unit shown by formula I, 16-27.5mol% unit shown by formula II and 16-27.5mol% unit shown by formula III and forms an optically anisotropic melt phase at <=350 deg.C is blended with (B) 5-500 pts.wt. inorganic compound having preferably >=30 aspect ratio in a molten ratio to give a resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin composition comprising a wholly aromatic polyester and an inorganic compound.

The resin composition provided by the present invention has excellent moldability and provides various molded products with excellent mechanical performance, thermal performance, etc.

[Conventional technology]

In recent years, there has been an increasing demand in the industry for higher performance organic polymer materials, and various types of fibers, films, injection molded products, etc. with excellent mechanical properties such as strength and modulus of elasticity, and thermal properties such as heat resistance have been increasing. The appearance of molded products is strongly desired.

Polyester, which forms an optically anisotropic melt phase, is a polymeric material that meets the above requirements! ! Thermotropic liquid crystal polyesters have attracted attention, and thermotropic liquid crystal polyesters having various structures have already been proposed, some of which are industrially produced.

Since the molecular chains of thermotropic liquid crystal polyester easily align in one direction, various molded products with high degree of orientation and excellent mechanical performance can be obtained from the polyester.

Furthermore, it is known that various molded products obtained from thermotropic liquid crystalline polyesters consisting of aromatic compounds in which all the skeletons are bonded in a 100-point shape have extremely good heat resistance.

On the other hand, various molded products obtained from thermotropic liquid crystalline polyester (1%) and injection molded products have large mechanical anisotropy because, as mentioned above, the molecular chains of the polyester constituting the product are oriented in one direction. becomes. Please note that this molded product is easily fibrillated, and 1 and 9 fibrils are easily peeled off from the surface of the molded product. In order to reduce the mechanical anisotropy of the molded article and suppress fibrillation on one surface, thermotropic liquid crystal polyester is usually mixed with an inorganic compound such as glass fiber, Merck, or mica.

[Problem to be solved by the invention]

As mentioned above, nine thermodropink liquid crystalline polyesters mixed with inorganic compounds such as glass fiber, Merck, and mica have already been commercially available and used.

However, according to the studies of the present inventors, the conventionally known resin compositions of thermotropic liquid crystal polyester and inorganic compounds do not necessarily have sufficient moldability, especially when molding is called "paris" during injection molding. There is a lot of resin flowing out from the gaps, so when actually using injection molded products,
It turns out that [,ta. This generation of Paris is caused by high-speed molding,
This becomes a serious problem in the process when performing precision molding, etc.

An object of the present invention is to provide a resin composition of thermodropink liquid crystalline polyester and an inorganic compound that exhibits good moldability of 1% and exhibits very little flaking during molding.

[Means to solve the problem]

According to the invention, the above object is achieved substantially by repeating units 1. Consisting of II and ■ (some of the hydrogen atoms bonded to the ring may remain as an IIL group), 1: -o-Q-cu- ■: -oc-Q-eu- m = -o-υ(nυ-) Unit l is present in an amount of 40 to 750 to 75 mol%, and unit ■ and unit III are each present in an amount of 12.5 to 30 mol%.
, and consists of a wholly aromatic polyester in which the number of moles for the unit is substantially equal to that of the unit II, and an inorganic compound in an amount of 5 to 500 parts by weight per 100 parts by weight of the wholly aromatic polyester. The sole purpose is to provide a resin composition.

The unit I possessed by the wholly aromatic polyester of the present invention is derived from 4-hydroxybenzoic acid or a reactive derivative thereof, and is present in the wholly aromatic polyester in an amount within the range of 45 to 75 mol. The unit ■ is 9 terephthalic acid, which is fermented from its reactive derivative, and 12 in a wholly aromatic polyester.
．． Present in an amount ranging from 5 to 30 mole. Also, the unit is m
is derived from 4,4'-dihydroxydiphenyl ether or its reactive derivative, and is
Present in an amount within the range of 2.5-30 mol%. Note that the number of moles of unit II and unit III is substantially equal.

A portion of the hydrogen atoms bonded to the aromatic rings of units I, 2 and III may be substituted with an alkoxyl group having 1 to 4 atoms, and the halogen atoms or 1 may be substituted with a phenyl group.

In the present invention, the wholly aromatic polyester has substantially 1 unit
．． If and ■ Good 9, unit l is 45-685-68
% by mole, unit (I) and unit III are each present within the range of 16 to 27.5 mol, the number of moles of unit U and unit III are substantially equal, and 3
The resin composition, which is a thermotropic liquid crystal polyester that forms an optically anisotropic melt phase at temperatures below 50°C, has good moldability, mechanical performance, thermal performance, etc. This is preferable because it gives a molded product.

Unit I is 50-650-6 as a wholly aromatic polyester
5 mol%, unit n and unit m each exist within the range of 17.5 to 25 mol%, and form an optically anisotropic molten phase at a temperature of 350 ° C. or less Particularly preferred resin compositions are obtained when thermotropic liquid crystalline polyesters are used.

In the present invention, confirmation that the wholly aromatic polyester forms an optically anisotropic molten phase can be carried out using a Hirin optical microscope equipped with a heating device, for example, using a thin section of a sample of about 5 to 20 μm under direct Nicol light. This is done by observing that light passes through a temperature above a certain temperature. In addition, the observation was performed under high temperature.

Apply light pressure to the sample sandwiched between the cover glasses, or
Alternatively, the transmission of polarized light can be observed more reliably by moving the cover glass. The temperature at which polarized light begins to be transmitted is the transition temperature to the optically anisotropic molten phase for that sample. This transition temperature is the differential scanning M1 meter (L) SC
) to raise the temperature at a constant temperature increase rate, for example, at a rate of 10 to 2037 minutes.

It can also be determined by observing the thermal behavior of the sample and the position of its endothermic peak. Note that the endothermic peak observed by the differential scanning calorimetry needle of the thermotropic liquid crystal polyester preferably used in the present invention is very small compared to the crystal melting peak to the isotropic phase of ordinary crystalline polymers, so the measurement It is necessary to pay sufficient attention to However, the above-mentioned endothermic peak may become clear by heat treating the sample at an excessive temperature below the transition temperature for a certain period of time, for example within the range of 5 minutes to 1 hour. Two or more endothermic peaks may appear, or the temperature giving the largest peak may be taken as the transition temperature. In some cases, the transition temperature determined by observation using a polarizing microscope and the transition temperature determined by L)SC measurement are not the same, but in such cases, the higher temperature is determined as the anisotropic temperature. It is regarded as the transition temperature to the molten phase.

The wholly aromatic polyester used in the present invention can be produced by various ester-forming reactions, but is usually produced by melt polymerization. In the normal case, it gives the unit I4
-Hydroxybenzoic acid and 4,4-dihydroxydiphenyl ether giving the unit (2) have their hydroxyl groups converted into lower acyl esters and are then subjected to a polymerization reaction. As the lower acyl ester, acetic acid ester is most preferred.

Polymerization is carried out in the presence of a catalyst and in the absence of a catalyst.

As a catalyst, a transesterification catalyst is usually used, and the amount used is t-i total monomer weight 0.0 O1 to 1 overlapping amount ti.

Preferably about 0.005 to 0.5 weight! This is a view of the inside of Tonohan. Examples of transesterification catalysts include alkali metal salts or alkaline earth metal salts of carboxylic acids, alkyl tin oxides, diaryl tin oxides, alkyl stannic acids, titanium dioxide, alkoxy titanium silicates, titanium alkoxides, Lewis acids, hydrogen halides, etc. can be mentioned.

Melt polymerization is usually carried out at a temperature in the range of 200 to 450°C under an atmosphere of an inert gas such as nitrogen or argon.

It is preferably carried out under a flow of the inert gas or under reduced pressure. As the polymerization progresses, fat-carboxylic acids such as acetic acid are distilled out depending on the type of esterification compound of the hydroxy compound, which is the starting material compound.
The reaction temperature is raised stepwise depending on the amount of distillation and the viscosity of the polymer.

Also adjust the degree of pressure reduction. Polymerization time usually ranges from 1 to 10 hours. After the melt polymerization is completed, the polymer is finely pulverized and further polymerized in the solid phase at a temperature below the melting point.
O that can also increase the degree of polymerization The wholly aromatic polyester thus obtained is a linear polyester having repeating units with a t-mol composition corresponding to the amount of each raw material compound charged.

The wholly aromatic polyester used in the present invention is one whose logarithmic viscosity at 60°C, obtained by dissolving it in pentafluorophenol at a concentration of 0.1 weight/volume, is 0.5 J/f or more. Preferably sl, 0cl
It is more preferable to obtain J/f or more. Logarithmic viscosity is 0.
A molded article obtained from a resin composition containing a wholly aromatic polyester with a size smaller than 5 dll/f has insufficient mechanical properties and is therefore undesirable.

Although the upper limit of the logarithmic viscosity of the wholly aromatic polyester used in the present invention is not critical, it is usually 7.5alt or less, preferably 6d17r or less, in order to facilitate the polymerization of the wholly aromatic polyester and to Aromatic polyesters are desirable because of their good moldability and the mechanical performance of molded products provided by resin compositions containing fully aromatic polyesters.

5 to 100 parts by weight of the above fully aromatic polyester
The resin composition of the present invention can be obtained by melt-mixing 500 parts by weight, preferably 10 to 250 parts by weight, more preferably 15 to 100 parts by weight of an inorganic compound. Examples of inorganic compounds used include glass fiber, carbon fiber, talc, mica, silica, alumina, calcium carbonate, and wollastonite. When an inorganic compound having an aspect ratio of 30 or more is used, a molded article with particularly improved mechanical properties can be obtained. The cross-crossing of the wholly aromatic polyester and the inorganic compound is carried out using a cross-crossing machine 1 such as a -screw extruder, a twin-screw extruder, or the like. The cross-crossing operation is carried out at a temperature higher than the melting point of the wholly aromatic polyester or a temperature higher than the transition temperature to an optically anisotropic melt phase, preferably at a temperature 5 to 50°C higher than said temperature, for a period of about 1 to 30 minutes. It will be done. The inorganic compound is substantially uniformly dispersed within the wholly aromatic polyester. For this.

It is preferable to use the inorganic f and metal after surface treatment with a known silane camping agent etc. The resin composition of the present invention is usually used in a cylinder, although it depends on the composition of the wholly aromatic polyester used. Temperature is 280-400
Melt molded within the range of °C. The resin composition of the present invention is particularly preferably used for injection molding. The mold temperature when performing injection molding is room temperature to 200°C, preferably 50°C to
Temperatures within the range of 150°C are employed. Injection pressure is 300-1500kf/d, molding cycle is 1
0 to 180 seconds, screw rotation speed 100 to 20
0rprn is used respectively.

The resin composition of the present invention has good moldability, and is particularly characterized by significantly less occurrence of flakes during injection molding.

This low occurrence of flakes during injection molding is a feature not seen in other conventionally known compositions of thermotropic liquid crystal polyester and inorganic compounds. Molded articles obtained from the resin composition of the present invention not only have excellent mechanical performance and thermal performance, but also have the characteristics of low mold shrinkage and high hardness.

The molded article obtained from the resin composition of the present invention takes advantage of the above-mentioned features and can be preferably used, for example, in the following fields.

(1) Electrical/electronic parts 1 e.g. connector switch,
Printed wiring board, bobbin, coverteg carrier
Relay cases, terminals, etc.

(2) Mechanical parts, such as fans, pulleys, cover pumps, gears, parts cases, power tools, etc.

(8) Automotive parts, such as engine parts, lamp housings, etc.

(4) Miscellaneous goods 1 such as food containers, trays, etc.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

Reference example 1 Reaction tank with double helical ribbon type stirring blades (inner diameter:
440 whale, internal volume near 01. 17.043 kf of 4-hydroxybenzoic acid, 6.840 kf of terephthalic acid, 8.236 kg of 4,4-dihydroxydiphenyl ether, and 21.050 kf of acetic anhydride were charged into a 5 US 318 L). After the inside of the system was sufficiently purged with nitrogen gas, the oil bath temperature of the reaction tank was heated to 150° C., and the mixture was refluxed for 2 hours while stirring. Note that the rotation speed of the stirring blade was 70 revolutions per minute. After 2 hours, the internal temperature of the reaction cell was raised to 220°C over 1 hour.
Then, the temperature was raised to 260°C over 1 hour, then raised to 320°C over 1 hour and 20 minutes, and held at 320°C for 20 minutes. During this period, a total of 23.80 kg of acetic acid and acetic anhydride were distilled out. Next, the internal temperature of one reaction tank was raised to 340° C., and the pressure inside one reaction tank was gradually reduced to reach 501111Hf over 30 minutes. Furthermore, gradually depressurize K
L, 5 wr H in 30 minutes? It reached this point.

At this point, nitrogen gas was introduced into the system and the pressure was returned to normal to stop the reaction.Next, while the reaction tank was kept at 340°C, a small amount of polymer was taken out in the form of a strand from one reaction tank.
Cut into pellets using a regular strand cutter. The logarithmic viscosity of the obtained polymer is z, s6g, 'r,
The yield was 90% based on the theoretical yield.

Note that the logarithmic viscosity was calculated using the following formula.

Fall time of pentafluorophenol measured at 60°C using a toH Ubbelohde viscometer (excerpt).

t: Falling time (seconds) of a solution obtained by dissolving a sample in pentafluorophenol.

C: Concentration of sample Cf/dl) Microscopic pieces of this polymer were heated using a microscope heating device [Linker A
(manufactured by Linkarn) in a TH-600E under a nitrogen μ atmosphere at a rate of 10° C./min. As observed by M, light began to be transmitted at 283°C, and the amount of transmitted light became even larger at around 305°C. It was confirmed that the resulting polymer forms an optically anisotropic melt phase.

However, this polymer was subjected to 1H-NMR, (JOELGX-
500) According to the analysis, 4-
oxybenzoyl unit, terephthaloyl unit and 4,
The molar ratio 'l'1 of 4-dioxydiphene=1 is approximately 60:2
It was confirmed that the molar ratio of 0:20 was substantially the same as the molar ratio of the raw material compound.

Reference Examples 2 and 3 In Reference Example 1, the molar ratio of 4-acetoxybenzoic acid, terephthalic acid and 4.4-diacetoxydiphenyl ether was 55:22.5:22.5t or 64:18:18, respectively. Polymerization was carried out in the same manner except that the logarithmic viscosity of the obtained polymer was 2.34 d.
ll/f and 2.86 dE/f. When observed using a polarizing microscope, these polymers each had a molecular weight of 290
It was confirmed that an optically anisotropic molten phase was formed at temperatures of 0.degree. C. or higher and 292.degree. C. or higher.

Example 1 100 parts by weight of the polymer obtained in Reference Example 1 and 67 parts by weight of glass fiber FA (chopped strand C83J-941SP manufactured by Nitto Boseki Co., Ltd.) were mixed into a -axially extruded rock (UT- manufactured by Plastic Engineering Research Institute). 40-H)k, cylinder temperature 275-305°C.

There was crosstalk under the conditions of a screw rotation speed of 70 rpm and a discharge rate of 14 Kf/hour. The obtained resin composition was put into an injection molding machine (
Nissei Resin Kogyo Co., Ltd. 111Fs8012AsE), cylinder temperature 285~310℃, mold temperature 90~
The connector metal was molded into a connector under the condition of 95℃, and no formation of flakes was observed, and the moldability was extremely good.The mold was replaced with a test piece mold for measuring physical properties. A test piece was prepared, various physical properties of the test piece were measured, and the results were summarized in Table 1. The molding shrinkage rate in the flow direction of the resin of the test piece was 0%, and the molding shrinkage rate in the direction perpendicular thereto was 0.3%. The Rockwell hardness of the test piece was 68 (M scale).

Example 2 100 parts of the polymer obtained in Reference Example 2 and 800 weight of the same glass fibers used in Example 1 were kneaded in the same manner as in Example 1. A connector and a test piece were prepared using the obtained resin composition in the same manner as in Example 1, and the results showed that no flaking occurred and the moldability was extremely good. Table 1 summarizes the results of measuring various physical properties of the test pieces.

Example 3 100 parts by weight of the polymer obtained in Reference Example 3 and 100 parts by weight of Merck (Hayashi Kasei Co., Ltd. a Micron White 5oo)
os) were kneaded in the same manner as in Example IK. In addition, for the talc, add a silane coupling agent (A-1100 manufactured by Nippon Unicar Co., Ltd.) by 0.5% by weight to the talc.
It was used after surface treatment. Using the obtained resin composition, a connector and a f
: When a scissors piece was prepared, no flaking occurred and the moldability was extremely good. Various physical properties of the test piece? The measured results are summarized in Table 1.

1st Table 1 1640 9.27X10 12
2282 1540 8.97X
10 17 2193
1080 3.15X10 15
Measured at 156.

〔Effect of the invention〕

The resin composition provided by the present invention has good moldability and generates very little flaking during injection molding. Molded articles obtained from the resin composition of the present invention not only have excellent mechanical and thermal performance, but also have low mold shrinkage and high hardness.

Claims (1)

[Claims] 1. Substantially consisting of the following repeating units I, II and III (a portion of the hydrogen atoms bonded to the ring may be substituted with a substituent), I: ▲ Formula , chemical formulas, tables, etc. ▼ II: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ III: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Unit I is present in the range of 40 to 75 mol%,
Unit II and unit III are each 12.5 to 30 mol%
and an inorganic compound in an amount of 5 to 500 parts by weight based on 100 parts by weight of the wholly aromatic polyester. Resin composition. 2. The wholly aromatic polyester is essentially a repeating unit I
, II and III, the unit I is present in the range of 45 to 68 mol%, the unit II and the unit III are each present in the range of 16 to 27.5 mol%, and the unit
The number of moles of II and unit III is substantially equal, and 350°C
The resin composition according to claim 1, which is a wholly aromatic polyester that forms an optically anisotropic melt phase at a temperature of: