JPH03243648A - Reinforced liquid crystal resin composition - Google Patents

Abstract

PURPOSE:To obtain a reinforced resin composition having excellent heat resistance, mechanical characteristics and moldability by blending a specific liquid crystal polyester resin with specific amounts of glass fibers having different average fiber diameters. CONSTITUTION:(A) 100pts.wt. liquid crytal polyester resin shown by formula I to formula IV (R1 is group shown by formula V, formula VI, etc.; R2 is formu la V, formula VI, formula VII, etc.) moldable in a molten state is blended with (B) 5-200 pts.wt., preferably 10-100 pts.wt. of B1: glass fibers having 3-10mum average fiber diameter and B2: glass fibers having 10-20mum average fiber diame ter in the weight ratio of B1/B2=1/9-9/1, preferably 3/7-7/3 and optionally (C) 0.2-30pts.wt., preferably 1-20 pts. wt. organic flame-retardant [e.g. ethylenebis-(tetrabromophthalimide)].

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a glass fiber-reinforced liquid crystal resin composition excellent in heat resistance, moldability, mechanical properties, especially Izot impact strength and anisotropy. .

<Conventional technology> In recent years, the demand for high performance plastics has been increasing, and many polymers with various new performances have been developed and put on the market. Optically anisotropic liquid crystal polymers are attracting attention because they have excellent mechanical properties.

Examples of polymers that form an anisotropic melt phase include liquid crystal polymers obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (Japanese Patent Application Laid-open No. 72393/1983);
A liquid crystal polymer obtained by copolymerizing p-hydroxyammonium, ferroic acid and 6-hydroxy-2-naphthoic acid (Japanese Patent Application Laid-Open No. 54-776
91), and p-hydroxybenzoic acid with 4°4-
Liquid crystal polymers made by copolymerizing monodihydroxybiphenyl, terephthalic acid, and isophthalic acid (Japanese Patent Publication No. 57-24407) are known.

Furthermore, it is known that glass fibers are added to liquid crystal polymers in order to improve their heat resistance and mechanical strength.

<Problems to be Solved by the Invention> However, the liquid crystal polymers known so far have a low deflection temperature under load of less than 90°C, and have insufficient heat resistance, or have a deflection temperature under load of 190°C. Although the heat resistance is good as above, the liquid crystal start temperature is too high.
It has been difficult to obtain a liquid crystal polymer that has a balance between heat resistance and moldability, as it cannot be molded unless the temperature is 0° C. or higher and has a high melt viscosity.

In addition, adding glass fiber to liquid crystal polymer increases mechanical strength.
Although heat resistance is improved, there are problems such as a decrease in fluidity.There is a method of copolymerizing monomers containing ethylenedioxy units to improve fluidity, but there are problems such as a decrease in heat resistance. there were. Moreover, it has been found that even if glass fiber is added to these liquid crystal polymers, the anisotropy cannot necessarily be said to be sufficiently low.

Therefore, the present invention solves the above problems and provides a three-layer chemical product with excellent heat resistance, mechanical properties, excellent moldability, and low anisotropy.
The objective is to obtain a resin composition.

Means for Solving the Problems> As a result of the inventors' intensive studies to solve the above problems,
We have arrived at the present invention.

That is, the present invention provides: (1) An average fiber diameter of 3 μm or more and 10 μm for 100 parts by weight of a melt-mouldable liquid crystal polyester resin consisting of the following structural units (I>, (II), (II), and <IV).
Glass fibers with an average fiber diameter of less than 10μm or more than 20μm
A reinforced liquid crystal resin composition obtained by filling 5 to 200 parts by weight of glass fiber in combination with less than or equal to Indicates the group. Moreover, X in the formula represents a hydrogen atom or a chlorine atom. (2) The reinforced liquid crystal polyester composition according to claim (1) further contains 0.2 to 30 parts by weight of an organic flame retardant based on 100 parts by weight of the liquid crystal polyester.

The above structural unit (I> is a structural unit of polyester produced from p-hydroxybenzoic acid, and the structural unit (II)
is a structural unit produced from 4,4゛-dihydroxybiphenyl, and the structural unit (III) is hydroquinone, 2
．． 6-hydroxynaphthalene, t-bunalhydroquinone, 33-. 5.5-tetramethyl-4,4-monodihydroxypiphenyl, phenylhydroquinone, 4.
The structural unit (1v) is a structural unit produced from T or more dihydroxy compounds selected from 4-1 dihydroxy diphenyl ether and ethylene glycol, and the structural unit (1v) is terephthalic acid, 4,4-diphenyldicarboxylic acid, 2,6-
Natutala dicarphonic acid, 1,2-bis(phenoxy)
Ethane-4,4”-dicarboxylic acid, ■, 2-2-2-
Each shows a structural unit produced from one or more aromatic dicarboxylic acids selected from chlorophenoxy)ethane-4,4 dicarboxylic acid and 4,4-cyphenyl ether dicarboxylic acid.

Particularly preferred.

Among the structural units (I) to (1v), the structural unit (
In II), when R1 is -CH2CH2-, the structural unit [(I>+(n)] is [(1) + (II> +
(III)] is preferably 775 to 95 mol, and 82
-93 mol% is more preferable, and 85-90 mol% is particularly preferable.

Moreover, the structural unit (III) is [(I>+NI>+(■)]
225 to 5 mol%, preferably 18 to 7 mol%,
More preferably, it is 15 to 10 mol%. Structural unit [
(1)+ (II)] becomes [(1)+ (If)+ (I
If it exceeds 95 mol% of [l)], melt fluidity decreases and solidification occurs during polymerization, resulting in 75 mol%? If it is smaller than ≦, the heat resistance will be poor, which is not preferable. Moreover, the structural unit (I>/(n
) is 75/25 to 9515, preferably 78/22 to 93/7. If it is less than 75/25 or greater than 9515, the heat resistance and fluidity will be poor, making it impossible to achieve the object of the present invention. Moreover, the structural unit (IV) is the structural unit [(II>+ (III
)] is substantially equimolar.

In addition, when the structural unit <1> is other than R4 or -CH2CHz-, the structural unit (1) is [(I) + (n)
+(III)] is preferably 440 to 90 mol%, more preferably 60 to 88 mol%, particularly preferably 70 to 90 mol%
It is 85 mol%.

The structural unit (In> is [(1) + (II) + (1)]
If it is more than 990 mol %, the melt fluidity decreases and solidification occurs during polymerization, and if it is less than 40 mol %, the heat resistance becomes poor, which is not preferable.

Further, the molar ratio of the structural unit (II>/(II)) is 1/
9 to 9/1, preferably 7.5/2.5
~2.5. /7. ．． 5, particularly preferably 7.5/2,5
~4/6. ) If it is less than 79 or greater than 97/1, the heat resistance and fluidity will be poor, making it impossible to achieve the object of the present invention.

Moreover, the structural unit (1v) and the structural unit [(n)+(■)] are substantially equimolar.

The method for producing the liquid crystal polyester used in the present invention is not particularly limited, and it can be produced according to known polyester polycondensation methods.

Furthermore, the melt viscosity of the liquid crystal polyester used in the present invention is 1
0 to 15,000 poise is preferred, especially 20 to 5.0
00 poise is more preferable.

Note that this melt viscosity is a value measured using a Koka type flow tester under conditions of a shear rate of 1.000 (1/sec). Here, the melting point (T
m) is a temperature increase rate of 20℃/
The endothermic peak temperature observed when measured in minutes, T
Points to m2.

In other words, the endothermic peak temperature (Tm+) observed when the polymer after polymerization is measured from room temperature to a temperature higher than the melting point at a temperature increase of 20°C/min is Tm, +20°.
Shows the endothermic peak temperature (Tm2) observed when held at a temperature of C for 5 minutes, cooled down to room temperature under -20°C/min cooling conditions, and then measured again under 20°C/min heating conditions. .

On the other hand, the logarithmic viscosity of this liquid crystal polyester is 0°1 g
/ dE It can be measured in pentafluorophenol at 6 degrees and 60°C, preferably 0.5 to ↑Od, Q/g, and especially 1.0 to 1.0 when containing -CH2CH2- as the structural unit (III). 3.0 dR/g is particularly preferred.

In addition, when polycondensing the liquid crystal polyester used in the present invention, 3,3-1 diphenyl dicarboxylic acid, 2,2-di' phenyl dicarboxylic acid, 2,2-di' phenyl dicarboxylic acid, etc. Aromatic dicarboxylic acids such as dicarboxylic acid,
Aliphatic dicarboxylic acids such as adipic acid, acelaic acid, sebacic acid, toti'candioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone', methylhydroquinone, 4.4 dihydroxydiphenyl sulfide, 4 , aromatic diols such as 4-dihydroxyhensiphenone, 1,4-butanediol, 1
, 6 hexanediol, neopentyl glycol, ),
Aliphatic, cycloaliphatic diols such as 4-cyclohexanediol, 1,4-cyclohexane dimetatool and m-
Aromatic hydroxycarboxylic acids such as hydroxybenzoic acid and 2°6-hydroxynaphthoic acid, or aromatic imide compounds may be further copolymerized in a small proportion so as not to impair the object of the present invention.

The glass fibers used in the present invention are preferably weakly alkaline, as they have excellent mechanical strength and are suitable for reinforcing liquid crystal polyester resins.

Glass fiber has an average fiber diameter of (a) 3 μm or more■○μm
It is essential to use in combination the ungrooved range and (b) the fiber average diameter range of 10 μm or more and less than 20 μm,
The glass fiber (a) preferably has an average fiber diameter of 4 to 9.
, 8 μm. The fiber length is preferably 30 to 104 μm, more preferably 000 to 4000 μm.

The glass fiber (b) preferably has an average fiber diameter of 10 to
It is 16 μm. The fiber length is preferably 30 to 10' μm, more preferably 1000 to 4000 μm.

The amount of glass fiber [(a>+(b)) filled is 5 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polyester.

Further, the weight ratio of the glass fibers (a)/(b) is preferably 1/9 to 9/1, more preferably 3/7.
~7/3.

When glass fiber (a) is used alone, there is a decrease in IZOd impact strength, and when glass fiber (b) is used alone, the effect of reducing anisotropy is small (glass fiber (a> is the fiber average) If the glass fiber (b) is less than 3 μm in diameter, the reinforcing effect will be small, resulting in little improvement in mechanical strength, and if the glass fiber (b) has an average fiber diameter of 20 μm or more, the fluidity will deteriorate, which is not preferable.

Further, it is preferable to add an organic flame retardant to this resin composition, since it not only imparts flame retardance but also further improves this anisotropy reducing effect.

There are no particular limitations on how to make glass fibers having the above-mentioned diameters, and it is preferable to grind and cut spun long fibers with uniform diameters.

Glass fibers treated with a silane-based coupling agent are preferably used, and epoxy silane-based ones are particularly preferred. Moreover, it is preferable that it be treated with an epoxy-based sizing agent.

In the present invention, the structural unit (
When R1 in III) is -CH2CH2-, it is more preferable to add an organic flame retardant. The organic flame retardant is an organic bromine compound and/or an organic phosphorus compound, and the organic bromine compound has a bromine atom in its molecule, and preferably has a bromine content of 20% by weight or more.

Specifically, low molecular weight organic bromine compounds such as decabromodiphenyl ether and ethylene bis(tetrabromophthalimide), brominated polycarbonates (for example, polycarbonate oligomers produced using brominated bisphenol A as a raw material or copolymers thereof with bisphenol A) ), brominated epoxy compounds (for example, jepoxy compounds produced by the reaction of brominated bisphenol A and epichlorohydrin, and monoepoxy compounds obtained by the reaction of brominated phenols and epichlorohydrin), poly(brominated benzyl acrylate), bromine halogenated polyphenylene ether, brominated bisphenol A, condensates of cyanuric chloride and brominated phenol, brominated polystyrene, crosslinked brominated polystyrene, crosslinked brominated poly-α-methylstyrene, or halogenated polymers and oligomers thereof; Preference is given to mixtures of ethylene bis-(tetrabromophthalimide), brominated epoxy oligomers or polymers, brominated polystyrene, crosslinked brominated polystyrene, brominated polyphenylene ethers and brominated polycarbonates, especially ethylene bis-(tetrabromophthalimide), Phthalimide>, brominated polystyrene, and brominated polycarbonate are particularly preferably used.

The amount of these organic flame retardants added is 100% of liquid crystal polyester.
It is preferably 0.2 to 30 parts by weight, more preferably 2 to 20 parts by weight, but the flame retardance is determined by -0CH2C of the structural unit (III) of the liquid crystal polyester.
Since it is closely related to the copolymerization amount of H20-, it is preferable to use the following addition amount. That is, the amount of the organic bromine compound added is preferably 60 to 280 parts by weight, particularly preferably 100 to 200 parts by weight, based on 100 parts by weight of ethylenedioxy units in the liquid crystal polyester.

On the other hand, the organic phosphorus compound used in the present invention has a phosphorus atom in its molecule, and is a compound synthesized from phosphoric acid, phosphorous acid, phosphonic acid, etc., phosphine,
Compounds such as phosphine oxide and phosphorane, compounds having the following structural formulas, and polymers containing these compounds as at least one component.

Examples of this polymer include polymers having the following structural units.

O 1 -(-0-P-R2-CO-)- 1 Among these, the most preferred organic phosphorus compound is the following polymer.

0 0 ri11 ÷P-0-R20÷-+P-○-R20-)-R,OR
.

Note that some of these organic phosphorus compounds may be metal salts. The amount of this organic phosphorus compound added is determined by the structural formula (I>,
(II), (1) and (1v>), the structural unit (In> It is preferably 2 to 150 parts by weight, and particularly preferably 0 to 100 parts by weight, based on 100 parts by weight.

In addition, in the present invention, a small amount of an organic bromine compound, preferably brominated polystyrene, brominated polycarbonate, brominated epoxy polymer, or brominated polyphenylene ether, may be used in combination, and the organic phosphorus compound may be used in combination with a polymer consisting of the following structural units. It may also be an organic phosphorus compound containing bromine.

When R1 of structural unit (1) is -CH2CH2-, structural unit (III) is structural unit [(■)+ (n)+
(1)] is 55 to 25 moles, so the amount of flame retardant added is UL94 standard vertical combustion test (ASTM
D790 standard>, it can be made into V-O with a thickness of 1/32".If the structural unit (III) is less than 5 mol%, the melting point of the liquid crystal polyester becomes high, so the liquid crystal polyester decomposes and polymerizes when melted by the flame retardant. Even if a filler is added, the mechanical properties may deteriorate or the molded product may drip during combustion, which is undesirable.On the other hand, if the structural unit (1) is more than 25 mol%, the deflection temperature under load may decrease. Not only does the heat resistance of the material significantly decrease, but it is also necessary to add large amounts of organic bromine compounds and organic phosphorus compounds to impart flame retardancy, and it is also necessary to further add flame retardant aids such as antimony compounds. This is not preferable because the mechanical properties are greatly reduced.

The present invention can further contain the following fillers, including carbon fibers, aromatic polyamide fibers, potassium titanate fibers, gypsum fibers, brass fibers, stainless steel fibers, steel fibers, ceramic fibers, boron whisker fibers, mica, and talc. , silica, calcium carbonate, glass peas, glass flakes, glass microballoons, clay,
Examples include fibrous, powder, granular, or plate-like inorganic fillers such as wollastenite and titanium oxide.

Furthermore, the composition of the present invention may contain antioxidants and heat stabilizers (such as hindered phenol, hydroquinone, phosphites, and substituted products thereof), ultraviolet rays, etc., to the extent that the object of the present invention is not impaired. Absorbents (e.g. resorcinol, salicylates, benzotriazoles,
lubricants and mold release agents (such as montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene waxes), dyes (such as nitrosine) and pigments (such as cadmium sulfide, phthalocyanines, carbon black). etc.) and other thermoplastic resins, such as colorants, plasticizers, antistatic agents, etc.
Predetermined characteristics can be imparted.

The resin composition of the present invention is preferably melt-kneaded, and known methods can be used for melt-kneading. For example, the composition can be prepared by melt-kneading at a temperature of 200 to 350°C using a Banbury mixer, a Comroll machine, a kneader 1 single-screw or twin-screw extruder, or the like.

<Example> Hereinafter, the present invention will be explained in detail with reference to Examples.

Reference Example 1 994 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4°4-1-dihydroxyhyphenyl, 960 parts by weight of acetic anhydride, 112 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.
216 parts by weight of polyethylene terephthalate (6d, Il/g) was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and acetic acid depolycondensation was carried out under the following conditions.

First, under a nitrogen gas atmosphere) at 00 to 150°C for 5 hours.
After reacting at 250-320°C for 15 hours, 320°C
℃, reduced the pressure to 0.5 mmHiJ for 1 hour, and further
When the reaction was carried out for 5 hours to complete the polycondensation, a nearly theoretical amount of acetic acid was distilled out, resulting in a resin (a) having the following theoretical structural formula.
> obtained.

÷0−CH2CH2−○→−/k/N /m/n=80/7.5/12.5/0 Also, place this polyester on the sample stage of a polarizing microscope,
As a result of confirming the optical anisotropy by raising the temperature, the liquid crystal initiation temperature was 294° C., indicating good optical anisotropy. The melting point of this polymer was measured using a PerkinElmer DS (Model 7) at a heating rate of 20°C/min.
The peak temperature of Tm2 was 312°C. The logarithmic viscosity of this polyester (measured at 60°C in pentafluorophenol at a concentration of 0.1 g/d, Q) is 1.80 d, Q
/g, and the melt viscosity at 322° C. and a sliding speed of 1.000 (1/sec) was 800 poise.

Examples For 100 parts by weight of the liquid crystal polyester (A) of Reference Example 1, 30 parts by weight of glass fibers with a fiber diameter of 6 μm and a length of 3000 μm and 20 parts by weight of glass fibers with a fiber diameter of 13 μm and a length of 3000 μm were added using a ribbon blender. After mixing, the mixture was melt-kneaded and pelletized at 320°C using a 40 mmφ vented extruder. Next, the obtained pellets were subjected to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.), and the I
Zod impact measurement test piece (4″ x 1/2″ x 2.
5"'), 2 square plates with a thickness of 70 mm and 70 + mn, and 4 dumbbells were further shaped into the bottom shape.

The ASTM Nα4 dumbbell used a weld mold with gates at both ends of the dumbbell.

These specimens were subjected to IZOd impact tests according to ASTM D256 standard. -Measure the molding shrinkage perpendicular to the flow direction using a square plate, cut the square plate to a width of 14 mm in the direction perpendicular to the flow direction, and measure the bending elasticity under the conditions of a strain rate of 1 mm/min and a span distance of 40 ntm. ratio was measured and the ratio was used as a measure of anisotropy. In addition, according to ASTM D638 standard, AST
The breaking strength of M NQ 4 dumbbells was measured.

Example 2 Glass fiber 3 with a fiber diameter of 6 μm and a length of 3,000 μm was added to the liquid crystal polyester (A>100 parts by weight of Reference Example).
0 parts by weight, 20 parts by weight of glass fibers with a fiber diameter of 3 μm and a length of 3.000 μm, and further brominated polystyrene (“°Pyrocheck” 68PB manufactured by Yasan Ferro Co., Ltd.) 8
．． After mixing 5 parts by weight in a ribbon blender, the mixture was melt-kneaded and pelletized at 320°C using a 40 mmφ vented extruder. Next, the obtained pellets were subjected to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.), and combustion test pieces (1/32" and 1/8" x 1/2"x
5”) = IZod impact measurement test piece (top/4”
x, 1-/2” x 2.5”), 2 fence thickness x 70 x 7
The 0 m square plate was further molded into ASTMN (14 tanbells).

The ASTM Nc4 tan'bell used a weld mold on both ends of the kate or tanbell.

These test pieces were subjected to a vertical combustion test in accordance with the UL94 standard, and the results were -0. Furthermore, A.S.
An IZod impact test was conducted according to the TM D256 standard. On the other hand, the molding shrinkage rate perpendicular to the flow direction was measured using a square plate, and the square plate was cut to a width of 14 mm in the direction perpendicular to the flow direction.
The flexural modulus was measured under the condition of mm, and the ratio was used as a measure of anisotropy. In addition, the breaking strength of the ASTM D638 dumbbell, ASTM No. 4 dumbbell was measured.

Comparative Examples 1 to 4 Glass fiber (B) to the liquid crystal polyester (A) of Reference Example 1
, flame retardant (C) was added in the types and proportions shown in Table 1, mixed with a ribbon blender, and then melt-kneaded and pelletized at 260 to 320°C using a 40ITIITIφ vented extruder. Next, the obtained pellets were subjected to a Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 260 to 320°C and a mold temperature of 40 to 90°C. A molded article similar to 1 was obtained.

These molded products were evaluated in the same manner as in the examples.

These results are shown in the table below.

As is clear from Table 1, the molded product made of the liquid crystal polyester composition of the present invention has a higher weld strength than that of 2.3.4 in the comparative example, and combines the advantages of the two types of glass fibers. I can understand more.

<Effects of the Invention> The liquid crystal resin composition of the present invention has excellent heat resistance, moldability, and mechanical properties, especially IZOD street attack strength and weld strength. It will be done.

Claims (2)

[Claims] (1) The following structural units (I), (II), (III) and (
IV) melt moldable liquid crystalline polyester resin 10
A reinforced liquid crystal resin composition obtained by filling 5 to 200 parts by weight of glass fibers with an average fiber diameter of 3 μm or more and less than 10 μm and glass fibers with an average fiber diameter of 10 μm or more and less than 20 μm with respect to 0 parts by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) ▲Mathematical formulas , chemical formulas, tables, etc. ▼...(IV) (However, R_1 in the formula is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -CH_2CH_
2- R_2 has one or more groups selected from ▲Mathematical formula, chemical formula, table, etc.▼, ▲Mathematical formula, chemical formula,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Indicates one or more groups selected from. Moreover, X in the formula represents a hydrogen atom or a chlorine atom. ) (2) The reinforced liquid crystal polyester composition according to claim 1, further comprising 0.2 to 30 parts by weight of an organic flame retardant based on 100 parts by weight of the liquid crystal polyester.