JPH04246458A - Liquid crystal polyester composition - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal polyester composition lowered in the anisotropy of mechanical properties which is a defect of a liquid polyester without detriment to the excellent strengths, rigidity, etc., and without heightening the specific gravity. CONSTITUTION:A resin composition comprising 30-95 pts.wt. thermotropic liquid crystal polyester and 5-70 pts.wt. siloxane polyether imide copolymer.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to a resin composition containing a thermotropic liquid crystal polyester, and more particularly to a resin composition containing a thermotropic liquid crystal polyester and a siloxane polyetherimide copolymer.

0002

BACKGROUND OF THE INVENTION Thermotropic liquid crystalline polyesters are known. It has a rigid molecular skeleton and exhibits anisotropy in a molten state, and when molded, the rigid and rigid molecules are easily oriented by shear stress. Then, the molded product after cooling,
This orientation remains. The molded product has a self-reinforcing structure, exhibits high strength and high modulus of elasticity, and also has excellent heat resistance, dimensional stability, and chemical resistance. However, the mechanical properties of the molded product exhibit strong anisotropy and the weld strength is weak. In order to solve this problem, it is known to add various inorganic fibers or inorganic fillers to molding. Although this improves the drawbacks caused by the anisotropy of liquid crystal polyester to some extent, another drawback arises in that the specific gravity of the molded product increases.

[0003] Therefore, it has been proposed to add a powdered organic filler (JP-A-2-133467).
.

0004

[Problems to be Solved by the Invention] The present invention aims to provide liquid crystal polyester with excellent strength and rigidity while maintaining its original properties.
The purpose is to reduce the anisotropy of mechanical properties, which is a drawback, without increasing the specific gravity.

[0005]

The above objects are solved by adding a siloxane polyetherimide copolymer to a thermotropic liquid crystal polyester.

That is, the present invention provides a resin composition containing 30 to 95 parts by weight of a thermotropic liquid crystal polyester and 5 to 70 parts by weight of a siloxane polyetherimide copolymer.

The thermotropic liquid crystal polyester used in the present invention can be selected from the group of polyesters containing segments having the following structure.

-O-R-O- -CO-R-CO- -O-R-CO- Here, each R can be selected from the group shown below (Chemical formula 1).

[0009]

embedded image Further, the aromatic ring, aliphatic group, alicyclic group, etc. in R above may be substituted with a substituent selected from the group shown below (Chemical formula 2).

0010

[Chemical Formula 2] Next, the siloxane polyetherimide copolymer used in the present invention has the following formula (Chemical Formula 3):

[0011]

[In the above formula, T is a group of -O- or -O-Z-O-, where the divalent bond of -O- or -O-Z-O- is 3, Located at the 3'-, 3,4'-, 4,3'- or 4,4'- position, Z is as follows (Chemical formula 4):

0012

[C4] A group consisting of a divalent group represented by and the following formula (Chemical formula 5):

[
0013

embedded image {Here, X is -Cy H2y- (y is an integer from 1 to about 5), -C(=O)-, -(O=)S(=O)-
, -O- and -S-}, an aromatic bis(ether anhydride) represented by the following formula (I): H2
N-R-NH2 (I) [where R is (a)
(b) Aromatic hydrocarbon groups having from 6 to about 20 carbon atoms and halogenated derivatives thereof; (b) Alkylene groups having from 2 to about 20 carbon atoms; cycloalkylene groups having from 3 to about 20 carbon atoms; and (c) General formula (Chemical formula 6):

[0014]

[Chemical formula 6] {Here, Q is -S-, -O-, -C(=O)-, -(
O=)S(=O)-, and -Cp H2p- (p is an integer of about 1 to about 5)} A divalent organic group selected from the group consisting of ]
In a known method for producing polyetherimide from an organic diamine represented by the formula (I), part or all of the organic diamine represented by the formula (I) is replaced by the following formula (Chemical formula 7):

[0015]

embedded image where n and m are each independently an integer from 1 to about 10, preferably from 1 to about 5, and g is from 1 to about 40
, preferably an integer from about 5 to about 25).

When the organic diamine of formula (I) above and the amine-terminated organosiloxane of formula (7) are physically mixed prior to the reaction with bis(ether anhydride), a substantially random copolymer is formed. May form a union. Alternatively, block or alternating copolymers can be formed by forming polymers as is well known in the polymer art or by sequential addition of reactants.

Preferred amine-terminated organosiloxanes have m and n each of 3 and g of about 9 to about 2.
It has the above formula (Chemical formula 7) and has a molecular weight distribution having an average value in the range of 0.

The diamine component of the siloxane polyetherimide copolymer is generally about 20 to 50 mol % of the formula (Chemical formula 7)
of amine-terminated organosiloxane and about 50 to 80 mole percent organic diamine of formula (I). In preferred copolymers, the diamine component contains from about 25 to about 40 mole percent, most preferably about 30 mole percent, amine-terminated organosiloxane.

The siloxane polyetherimide copolymer used in the resin composition of the present invention can be produced by any method commonly used for producing polyetherimide, as described above. One currently preferred manufacturing method is that described in US Pat. No. 4,417,044.

The above-mentioned siloxane polyetherimide copolymer preferably has the following formula (Chemical formula 8)

[0021]:

[Chemical formula 8] Repeating unit represented by and the following formula (Chemical formula 9):

0022
]

embedded image (In the above formula, T and R are as defined above; m and n are each an integer of 1 to about 10; g is 1 to about 40
consisting essentially of repeating units denoted by ), which is an integer of Particularly preferably, the following formula (Chemical formula 10) is further added to this compound:
:

[0023]

[Chemical formula 10] [In the above formula, M is the following formula (Chemical formula 11):

[0024]

[Image Omitted] (In the above formula, B is -S- or -(O=)C-)
R' is R as defined above, or the following formula (Chemical formula 12):

[0025]

A divalent group represented by [Formula 12] (wherein m and n are each an integer of 1 to about 10, and g is an integer of 1 to about 40) Contains a repeating unit represented by do.

In the resin composition of the present invention, the siloxane polyetherimide copolymer is contained in an amount of 5 to 70 parts by weight, preferably 10 to 30 to 95 parts by weight, preferably 50 to 90 parts by weight, of the thermotropic liquid crystal polyester. ~5
Contains 0 parts by weight. If the amount of the siloxane polyetherimide copolymer is less than the above, the object of the present invention, that is, improvement of the anisotropy and weld strength of the molded article cannot be achieved. On the other hand, if this amount is greater than the above, the advantages of thermotropic liquid crystal polyester, that is, high strength and high rigidity, will not be exhibited.

[0027] The compositions of the present invention can also contain a polystyrene elastomer as an optional component. Polystyrene elastomer has the general formula (Chemical formula 13)

[0028]

embedded image (wherein, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, Z represents a substituent that is a halogen or an alkyl group having 1 to 4 carbon atoms, and p is a substituent having 1 to 5 carbon atoms) The polymer must contain at least 10% by weight of a repeating structural unit derived from a vinyl aromatic compound represented by (an integer). Examples of such styrenic elastomers include copolymers of styrene or its derivatives with polybutadiene, polyisoprene, and diene compounds (including random copolymers, block copolymers, graft copolymers, and hydrogenated products thereof). can be mentioned. Among these, hydrogenated products of ABA' type elastomeric block copolymers are particularly preferred.

The mixing ratio of the styrene elastomer to the siloxane polyetherimide copolymer is preferably 20 parts by weight or less per 100 parts by weight of the siloxane polyetherimide copolymer.

Further, in the present invention, other elastomer components may be included in addition to the above-mentioned styrene elastomer. Other elastomer components include natural rubber, butadiene polymer, isoprene polymer, chlorobutadiene polymer, butadiene-acrylonitrile copolymer, isobutylene polymer, isobutylene-butadiene copolymer, isobutylene-isoprene copolymer, and acrylic acid. Ester polymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, thiol rubber, polysulfide rubber, polyurethane rubber, polyether rubber (
Examples include polypropylene oxide, epichlorohydrin rubber, and the like.

In the present invention, other polymer components may be further copolymerized or blended. Other polymer components that may be copolymerized or blended include polyester, polyamide, polycarbonate, polysulfide, polyacrylate, polysulfone, polyetherketone, polystyrene, polyacrylonitrile, ABS.
, AS, polyolefin and the like.

[0032] The resin composition of the present invention may also contain, when mixing the resin, as long as it does not significantly impair its desirable properties.
Other resins and additives such as pigments, dyes,
Reinforcing agents (glass fiber, carbon fiber, etc.), fillers (carbon black, silica, titanium oxide, etc.), heat resistant agents, oxidative deterioration inhibitors, weathering agents, lubricants, mold release agents, plasticizers, flame retardants, fluidity improvement agent, antistatic agent, etc. can be added.

[0033] A preferred method for preparing the composition of the present invention is a melt-kneading method. The use of small amounts of solvent is possible, but generally not necessary. Examples of equipment include extruders, Banbury mixers, rollers, kneaders, etc., which are operated batchwise or continuously.

[0034]

[Example] In the example, the thermotropic liquid crystal polyester is Rodlan LC-
5000 (trademark, manufactured by Unitika Co., Ltd.) was used. As a siloxane polyetherimide copolymer, SILTE
MD9000 (trademark, manufactured by Japan GE Plastics Co., Ltd.) was used. Furthermore, as an optional component, SB
S rubber (styrene-butadiene-styrene copolymer, trademark: CARIFLEX TR1101, manufactured by Shell Chemical Co., Ltd.) was used.

[0035] Also, for comparison, talc LMS 1
00 (trademark, manufactured by Fuji Talc Co., Ltd.) was used. Examples 1 to 3 and Comparative Examples Amounts shown in the table (parts by weight) at 270°C in a twin-screw extruder
The raw materials were melt-mixed and extruded to make pellets. Sample pieces for various measurements were made from this pellet. The measurement results are shown in the table.

[0036] Here, the weld strength is ASTM D6
38, using a tensile test piece having gates at both ends. Izod impact strength (notched) is AS
Measured according to TM D256. Tensile strength is AS
Measured according to TM 638. Bending strength is AST
Measured according to M D790. HDT (heat distortion temperature) was measured according to ASTM D648. Note that mechanical properties other than Izod impact strength were measured in the direction of resin flow during molding.

[0037]

【table】

As is clear from the table, the resin composition of the present invention has greatly improved weld strength. The fact that the tensile strength in the flow direction of the resin is high and the strength in the weld region where the flow direction of the resin changes perpendicularly has been improved in this way means that the anisotropy of the liquid crystal polyester has been reduced. .

[0039]

Effects of the Invention The resin composition of the present invention has reduced anisotropy in mechanical properties while retaining the excellent strength and rigidity inherent to liquid crystal polyester, and does not have a high specific gravity, making it suitable for industrial use. very useful.

Claims (1)

[Claims] [Claim 1] Thermotropic liquid crystal polyester 3
A resin composition containing 0 to 95 parts by weight and 5 to 70 parts by weight of a siloxane polyetherimide copolymer.