JP3259108B2 - Liquid crystal polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition exhibiting optical anisotropy in a molten state. More specifically, the present invention relates to a polyester composition exhibiting optical anisotropy in a molten state with improved strength, processability, anisotropy, and the like.

[0002]

2. Description of the Related Art A wide variety of engineering plastics have been put on the market, and resins having excellent heat resistance and mechanical strength are widely used in electric and electronic parts, automobile parts, precision machine parts, etc. according to their characteristics. I have. However, the demand for higher performance is increasing more and more, particularly, polyesters comprising a rigid molecular chain and exhibiting optical anisotropy when melted (hereinafter sometimes referred to as LCP).
Is known for its low melt viscosity, good workability, and excellent mechanical properties and heat resistance.

[0003] However, these LCPs exhibit a high degree of orientation in the molten state, which tends to cause anisotropy in the mechanical properties, and also tends to warp in molded products, weak weld strength, easily fibrillate the surface, and peel off. It also has practical disadvantages such as ease of use.

Various methods have been studied as a method of alleviating the anisotropy. For example, the anisotropy is reduced by filling with glass fiber or inorganic filler.
If not filled, the effect will not be obtained and the workability which is the original feature of LCP will be sacrificed, and since the filler called glass fiber is blended, it can not be used for films and fibers, etc. Many are problems.

As a method for compensating for such a drawback, it has recently been developed as a polymer alloy or a polymer blend to mix various polymers to produce a new material. For example, LCP is also disclosed in JP-A-56-11535.
In Japanese Patent Application Publication No. 7 (1999), a blend of LCP and various polymers is studied.

However, in this blend, mechanical properties such as tensile strength and flexural modulus of LCP are not sufficient, and further improvement in anisotropy is not seen, so that it is not always satisfactory.

[0007]

Although various methods have been studied and published so far, there are few examples in which LCP is put into practical use, and products improved by filling with fillers are products. It's just This is because the polymer is highly oriented in the molten state, and as a result, the anisotropy increases. However, as described above, there is a disadvantage that workability is reduced.

[0008] In addition, even in the conventionally proposed blends with other resins, LCP is often poorly compatible with other resins due to its properties, and thus often undergoes phase separation. Surface fibrillation (fuzzing phenomenon) on the surface was severe, and it could not withstand practical use.

The present invention provides a polyester composition which exhibits optical anisotropy in a molten state while maintaining excellent processability of LCP and improving mechanical anisotropy and consequently improving mechanical properties. To provide.

[0010]

That is, the present invention relates to a resin composition comprising a polyester which exhibits optical anisotropy in a molten state as a main component and an alkali metal oxy organic compound blended with the polyester. .

The present invention will be further described below.

The polyester which exhibits optical anisotropy in a molten state used in the present invention is a thermoplastic meltable polymer which exhibits optical anisotropy when melted. Such a polymer exhibiting optical anisotropy at the time of melting has a property that polymer molecular chains take a regular parallel arrangement in a molten state. The properties of the optically anisotropic molten phase can be confirmed by a normal polarization inspection method using an orthogonal polarizer. In general, a polymer that does not show melt anisotropy becomes isotropic in a molten state, but when showing anisotropy in the melting process, it changes from a solid phase to an isotropic phase through an anisotropic liquid crystal phase.

Further, mechanical anisotropy can be confirmed. That is, when injection molding is performed, peeling and fibrillation of the surface of the molded article become remarkable, and the difference in physical properties between the direction of flow of the resin and the direction perpendicular to the direction can be confirmed.

The polyester exhibiting optical anisotropy in the molten state is generally known as a thermotropic liquid crystal polymer. The thermotropic liquid crystal polymer is generally made from monomers that are elongated, flat, and rigid along the long chain of the molecule and have multiple chain extension bonds in either a coaxial or parallel relationship. .

The polymer which exhibits optical anisotropy when melted is
It exhibits the property that the polymer molecular chains take a regular parallel arrangement in the molten state. The properties of the optically anisotropic molten phase can be confirmed by a usual polarization inspection method using a crossed polarizer.

The above-mentioned thermotropic liquid crystal polyester includes, for example, liquid crystalline polyester, liquid crystalline polyesterimide, etc., and more specifically, (wholly) aromatic polyester, polyesteramide, polyester carbonate and the like. That is, it is included in the scope of polyester as long as it contains a plurality of ester bonds in the molecule. Preferred polyesters are aromatic polyesters.

In the thermotropic liquid crystal polyester used in the present invention, a part of one polymer chain is composed of a polymer segment forming an anisotropic molten phase, and the remaining part does not form an anisotropic molten phase. Also included are polymers composed of polymer segments. Further, a composite of a plurality of thermotropic liquid crystal polymers is also included.

Representative examples of the monomers constituting the thermotropic liquid crystal polyester include (a) at least one kind of aromatic dicarboxylic acid, (b) at least one kind of aromatic hydroxycarboxylic acid type compound, and (c) aromatic diol type. (D) (d1) aromatic dithiol, (d2) aromatic thiophenol, (d3) at least one aromatic thiol carboxylic acid compound, (e) aromatic hydroxyamine, aromatic diamine-based compound At least one kind of compound is exemplified. Although these may be constituted independently, in many cases, (a) and (c), (a) and (d), and (a)
(B) and (c), (a) (b) and (e), or (a) (b) (c) and (e).

The aromatic dicarboxylic acid compound (a) includes terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid, 2,6-
Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,
4'-dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenyl ether-3,
3'-dicarboxylic acid, diphenoxyethane-3,3'-
Aromatic dicarboxylic acids such as dicarboxylic acid, diphenylethane-3,3′-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid,
Alkyl, alkoxy or halogen-substituted aromatic dicarboxylic acids such as dimethyl terephthalic acid, ethyl terephthalic acid, methoxy terephthalic acid, ethoxy terephthalic acid and the like.

(B) Examples of the aromatic hydroxycarboxylic acid compound include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 6-hydroxy-1-naphthoic acid. Carboxylic acid or 3-methyl-4-hydroxybenzoic acid, 3,5
-Dimethyl-4-hydroxybenzoic acid, 2,6-dimethyl-4, hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5-methyl -2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid,
2-chloro-4-hydroxybenzoic acid, 3-chloro-4
-Hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3
-Bromo-4-hydroxybenzoic acid, 6-hydroxy-
Alkyl, alkoxy or halogen substitution of aromatic hydroxycarboxylic acids such as 5-chloro-2-naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid, 6-hydroxy-5,7-dichloro-2-naphthoic acid Body.

(C) As the aromatic diol, 4,4 ′
-Dihydroxydiphenyl, 3,3'-dihydroxydiphenyl, 4,4'-dihydroxytriphenyl, hydroquinone, resorcinol, 2,6-naphthalenediol, 4,4'-dihydroxydiphenylether, bis (4-hydroxyphenoxy) ethane, Aromatic diols such as 3,3′-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane or chlorohydroquinone, methylhydroquinone, t-butyl Alkyl, alkoxy or halogen-substituted aromatic diols such as hydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chlororesorcin and 4-methylresorcin are exemplified.

(D1) Examples of the aromatic dithiol include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, and 2,7-naphthalene-dithiol.

(D2) As the aromatic thiophenol,
4-mercaptophenol, 3-mercaptophenol, 6-mercaptophenol and the like.

(D3) Examples of the aromatic thiolcarboxylic acid include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, and 7-mercapto-2-naphthoic acid.

(E) As aromatic hydroxyamine and aromatic diamine compounds, 4-aminophenol, N-
Methyl-4-aminophenol, 1,4-phenylenediamine, N-methyl-1,4-phenylenediamine,
N, N'-dimethyl-1,4-phenylenediamine, 3
-Aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol, 4-amino-
1-naphthol, 4-amino-4'-hydroxydiphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane,
4-amino-4'-hydroxydiphenyl sulfide,
4,4'-diaminophenyl sulfide (thiodianiline), 4,4'-diaminodiphenyl sulfone, 2,5-
Diaminotoluene, 4,4′-ethylenedianiline,
4,4′-diaminodiphenoxyethane, 4,4′-diaminodiphenylmethane (methylenedianiline),
4'-diaminodiphenyl ether (oxydianiline) and the like.

The thermotropic liquid crystal polyester used in the present invention can be produced from the above monomers by various ester forming methods such as a melt acidification method and a slurry polymerization method.

In terms of molecular weight, that of the thermotropic liquid crystal polyester suitable for use in the present invention is about 200
0 to 200,000, preferably about 10,000 to 1000
00. The molecular weight can be measured, for example, by measuring the terminal groups of the compressed film by infrared spectroscopy. GPC, which is a general measurement method involving solution formation, can also be used.

Among the thermotropic liquid crystal polymers obtained from these monomers, an aromatic polyester which is a (co) polymer containing a monomer unit represented by the general formula [I] as an essential component is preferable. The monomer unit preferably contains about 5 mol% or more.

[0029]

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A particularly preferred aromatic polyester of the present invention is a polyester represented by the general formula [II] having a repeating unit having a structure derived respectively from three compounds of p-hydroxybenzoic acid, phthalic acid and biphenol. The repeating unit having a structure derived from biphenol of the polyester may be a polyester having a part or the whole thereof substituted with a repeating unit derived from dihydroxybenzene), p-hydroxybenzoic acid and hydroxynaphthalenecarboxylic acid Is a polyester represented by the general formula [III] having a repeating unit having a structure derived from each of the two types of compounds.

[0031]

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[0032]

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The alkali metal oxy organic compound used in the present invention to be incorporated in the LCP is a compound having at least one substituent represented by the general formula [IV] in the molecule, and is generally an alkali metal alcoholate (or phenolate). )) Compounds.

[0034]

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Here, R represents a divalent hydrocarbon residue, and Me represents an alkali metal. This substituent is preferably present as a molecular terminal, and is more preferably an organic compound in which both terminals of the molecule are substituted with the substituent.

The alkali metal Me is specifically Li, N
a, K, Rb, Cs, Fr, preferably Na, K,
Particularly preferred is an alkali metal which is Na.

In the alkali metal oxy organic compound, the above-mentioned substituent forms an alkali metal alcoholate or phenolate. Therefore,
When the divalent hydrocarbon residue R is a non-aromatic hydrocarbon residue such as an aliphatic hydrocarbon residue or an alicyclic hydrocarbon residue, it forms a metal alcoholate, and phenylene, naphthylene, biphenylene, etc. Is a metal phenolate. That is, it is preferable that 50 mol% or more of the hydrogen atoms in the total of the aliphatic hydroxyl group and the aromatic hydroxyl group form a phenolate or an alcoholate with an alkali metal.

The divalent hydrocarbon residue R represented by the general formula (IV) has 1 to 20 carbon atoms, preferably an aromatic hydrocarbon residue having 6 to 20 carbon atoms which may have a side chain. Group. Specifically, it is a divalent hydrocarbon residue such as phenylene, naphthylene and biphenylene which may have an aromatic substituent.

It is necessary that the above specific substituent has at least one specific substituent in the molecule. Preferred forms of the substituent are those having a group at the terminal of the molecular chain.

As the alkali metal oxy organic compound,
There is no further limitation as long as it has the above specific substituent, but preferably it has a molecular weight of 500 to 500,000, preferably 50
Organic compounds in the range of 0-100,000. The mode at normal temperature may be liquid or solid. Preferably, it is a normal temperature solid organic compound. For improving the mechanical properties, a thermoplastic resin organic compound having a melting point of 100 ° C. or more is more preferable from the viewpoint of the melting point. The upper limit of the melting point is not particularly limited as long as it is thermoplasticized without thermal decomposition. Usually, the temperature is 400 ° C. or less.

Preferred organic compounds contain a repeating unit represented by the general formula [V] from the viewpoint of stability during compounding.

[0042]

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Here, X is a fluphonyl group (—SO ₂
And R ₁ and R ₂ are the same or different divalent aliphatic or alicyclic hydrocarbon residues or divalent aromatic hydrocarbon residues, and n is in the range of 3 to 50. Indicates an integer.

In addition, at least one of the molecular terminals of the organic compound is an alcoholic hydroxyl group or a phenolic hydroxyl group, and one of them forms an alcoholate or phenolate with an alkali metal. That is, the molecular terminal has a substituent represented by the formula (I).

In the formula (II), the groups R ₁ and R ₂ are the same or different divalent aliphatic or alicyclic hydrocarbon residues or divalent aromatic hydrocarbon residues. The number of hydrocarbon atoms in these residues is between 1 and 20
Range. Preferred divalent hydrocarbon residues are aromatic hydrocarbon residues having 6 to 20 carbon atoms such as phenylene, naphthylene or biphenylene which may have a side chain.

In addition, other repeating units such as a repeating unit derived from bisphenol-A or a repeating unit derived from 4,4-biphenol may be appropriately used as long as the repeating unit represented by the general formula (V) is included. Can be included.

The number of repeating units, n, is not particularly limited, but usually represents an integer in the range of 3 to 50. If the number is less than 3, it is difficult to obtain the effect of improving anisotropy. If the number is more than 50, the fluidity is reduced and moldability becomes difficult, which is not suitable for practical use.

For example, 4,4'-dichlorodiphenyl
A compound comprising a repeating unit derived from a sulfone,
More specifically, for example, a compound containing a repeating unit derived from 4,4′-dichlorodiphenyl sulfone and bisphenol A is used. And 4,4 '
Compounds having a repeating unit derived from -dichlorodiphenyl sulfone and 4,4'-biphenol are also exemplified. Compounds containing a sulfone skeleton as well as an ether group in the molecule, for example, compounds containing a repeating unit derived from 4- (4-chlorophenyl-sulfonyl) phenol are also exemplified.

In general, commercially available polyethersulfone resins and the like have hydroxyl groups at all molecular terminals because alkali metals are removed in advance by washing or the like. Therefore, they are distinct substances that are clearly distinguished from the organic compounds of the present invention.

Specific examples of the compound of the general formula (V) represented by the specific structural formula are as follows.

[0051]

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The method for producing the alkali metal oxyorganic compound of the present invention is not particularly limited, and it can be produced by a conventionally known method. As an example, Williamson
It can be synthesized by a synthesis method. For example, polymerization can be carried out by heating an alkali salt of 4,4′-dichlorodiphenylsulfone and 4,4′-dihydroxydiphenylpropane as monomers in an alkaline solvent such as sulfolane at 200 ° C.

The amount of the organic compound to be added to the LCP is usually 1 to 50 parts by weight based on 100 parts by weight of the LCP. Particularly preferably, it is 3 to 10 parts by weight. If the amount is less than 1 part by weight, the mechanical strength is not improved and the effect of improving anisotropy is small. If the amount exceeds 50 parts by weight, no improvement in strength is observed, processability is poor, and economical disadvantages are caused.

The composition of the present invention further comprises LCP
Alternatively, a third resin other than the above-mentioned organic compound may be blended.

The resin to be mixed may be either a thermoplastic column resin or a thermosetting resin, but is preferably a polyamide resin, a polycarbonate resin, a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyphenylene sulfide resin, a polyether sulfone resin, or a polysulfone. So-called thermoplastic engineering plastics such as resin polyetherketone resin and polyetheretherketone resin are exemplified.

The amount of the third thermoplastic resin is from 1 to 200 parts by weight, preferably from 1 to 100 parts by weight, more preferably from 1 to 50 parts by weight, per 100 parts by weight of the LCP of the present invention.
Parts by weight.

In addition, a reinforcing agent or a filler may be added to the resin composition obtained in the present invention in order to further improve heat resistance and mechanical properties. Specific examples of reinforcing agents or fillers include fibrous, powdery and mixtures of both. Examples of the fibrous reinforcing agent include glass fiber, shirasu glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, inorganic fiber such as metal fiber (for example, stainless steel fiber), and carbon fiber. Examples of the powdery reinforcing agent include silicates such as walasteinite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicate, alumina, silicon oxide, magnesium oxide, zirconia, and titanium oxide. Metal oxides, calcium carbonate, magnesium carbonate,
Carbonates such as dolomite, calcium sulfate, calcium pyrophosphate, sulfates such as barium sulfate, glass beads, boron nitride, silicon carbide, Saroyan and the like, which may be hollow (for example, hollow glass fiber, Glass micro balloon, shirasu balloon, carbon balloon, etc.). If necessary, the above-mentioned reinforcing agent may be pretreated with a silane-based or titanium-based coupling agent before use.

The resin composition of the present invention contains an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and substituted products thereof) as long as the object of the present invention is not impaired. Colorants, including UV absorbers (eg, resorcinol, salicylate, benzotriazole, benzophenone, etc.), bone and release agents, dyes (eg, nitrosine), and pigments (eg, cadmium sulfide, phthalocyanine, carbon black, etc.) Ordinary additives such as a flame retardant, a plasticizer, and an antistatic agent can be added to impart predetermined characteristics. The reinforcing agent, the filler and the like can be blended in an amount of up to 80% by weight, preferably up to 70% by weight, based on the whole composition.

The method of mixing the LCP of the present invention and the organic compound of the present invention is not particularly limited, and can be performed by a conventionally known method. For example, there are a method of reacting by heating and melting using an extruder, a method of mixing the organic compound of the present invention in the process of melt-synthesizing LCP, and a method of pulverizing this mixture and reacting it in a solid state.

In the present invention, the method of melt-kneading with an extruder is most preferable because it is simple and can be uniformly mixed. At this time, a small amount of a solvent can be appropriately added. As a device for melting and kneading, a Banbury mixer,
Although a static mixer roller, a kneader, or the like can be used continuously or batchwise, it is effective to use a single-screw extruder or a twin-screw extruder continuously.

In the method of mixing the third thermoplastic resin, the organic compound of the present invention may be mixed at the same time, or may be mixed in advance with a mixture of LCP and the organic compound of the present invention. Further, after the third resin is previously mixed with LCP, the organic compound of the present invention may be mixed.

[0062]

The present invention will be described in detail with reference to the following examples.

First, materials used in Examples and Comparative Examples will be described.

As a melt optically anisotropic polyester, LCP (A-1): Japanese Patent Application Laid-Open No. 2-38423
As described in Example 1, terephthalic acid , isophthalic acid, 4
-LCP powder synthesized from hydroxybenzoic acid and 4,4-dihydroxydiphenyl. Observation of the optical anisotropy using a polarizing microscope equipped with a hot stage showed optical anisotropy in a molten state at 340 ° C. or higher.

LCP (A-2): JP -A- 64-266
LCP synthesized from polyethylene terephthalate and 4-acetoxybenzoic acid according to the description in Example 1 of JP-A No. 32 . This polyester was in a molten state in a temperature range of 210 ° C. to 370 ° C. and exhibited optical anisotropy.

Alkali metal oxy organic compound

[0067]

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[0068]

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Metal alcoholate (B-1): 4,4'-
The dihydro carboxymethyl Formula B-1 of the phenyl sulfone and 4,4'-dichlorophenyl sulfone was synthesized in Saruforan solvent excess sodium hydroxide as a monomer
In which the average value of n is 30 .

Metal alcoholate (B-2): 4,4'-
Dihydro hydroxyphenyl sulfone, 4,4'-dichlorodiphenyl sulfone, Formula average value of n in B-2 is 20 metal alcoholate compounds synthesized in Saruforan solvent an excess of sodium hydroxide bisphenol -A as a monomer.

Metal alcoholate (B-3): 4,4'-
Dihydro hydroxyphenyl sulfone, average value of n in the formula B-3 of 4,4-biphenol synthesized in Saruforan solvent excess sodium hydroxide as monomers
20 metal alcoholate compounds.

Polyetheretherketone (PEEK) resin (trade name: Victrex 450G, manufactured by Sumitomo Chemical Co., Ltd.) other than LCP Tensile strength: 990 kg / cm ² , flexural strength 1450 kg
/ Cm ² , HDT 152 ° C. Polybutylene terephthalate (PBT) resin (manufactured by Toray)
Trade name: Toray PBT1401X06) Tensile strength: 570 kg / cm ² , bending strength 870 kg /
cm ^2, HDT58 ℃ polycarbonate (PC) resin (manufactured by Mitsubishi Gas Chemical product name Iupilon® S1000) tensile strength: 650kg / cm ^2, bending strength 870kg /
cm ² , HDT 136 ° C. was used.

EXAMPLES AND COMPARATIVE EXAMPLES Raw materials shown in the table were melt-mixed at a kneading part temperature of 350 ° C. in a twin-screw extruder and extruded to form pellets. From the pellets, sample pieces for various measurements were prepared by injection molding.

Evaluation items were tensile strength test (ASTM-D638) and HDT (:
The deflection temperature under load (ASTM-D648) was measured.

As an index for improving the mechanical anisotropy, the degree of fibrillation of the surface of the sample piece as the obtained molded article was confirmed.

The confirmation was performed by winding a commercially available adhesive tape around a steel rod having a diameter of 5 mm, and applying a force of 5 kgf to the surface of the test piece for 1 mm.
Rubbing was performed 0 times, and the trace was visually observed.

As an index of moldability, the appearance of a sample piece as an obtained molded product was visually confirmed.

The results are shown in the table.

[0079]

The effect of the present invention is that by mixing and improving a metal alcoholate with LCP, anisotropy is reduced, fibrils are suppressed, and mechanical strength is improved. INDUSTRIAL APPLICABILITY The present invention solves the problem of LCP and can broaden the application range, and is industrially useful.

[0080]

[Table 1]

[0081]

[Table 2]

Claims (2)

(57) [Claims] 1. A resin composition comprising a polyester which exhibits optical anisotropy in a molten state as a main component and an alkali metal oxyorganic compound added thereto. 2. The composition according to claim 1, wherein the alkali metal oxy organic compound contains a repeating unit represented by the following formula. Embedded image Here, X is a sulfonyl group (—SO ₂ —),
The groups R ₁ and R ₂ are the same or different divalent aliphatic or alicyclic hydrocarbon residues or divalent aromatic hydrocarbon residues, and n represents an integer in the range of 3 to 50.