JP7441721B2 - liquid crystal polymer - Google Patents

Description

The present invention relates to a liquid crystal polymer with excellent mechanical strength.

Liquid crystal polymers have excellent mechanical properties such as heat resistance and rigidity, chemical resistance, and dimensional accuracy, so their use is expanding not only to molded products but also to various applications such as fibers and films. In particular, electrical and electronic components are rapidly becoming more highly integrated, smaller, thinner, and lower in height, and in many cases very thin wall parts of 0.5 mm or less are formed, making liquid crystal polymers an excellent solution. Its usage has increased significantly due to its excellent moldability, that is, its good fluidity and no burrs, which are characteristics not found in other polymers.

In recent years, with the development of a highly information-oriented society, the amount and speed of information transmitted by information and communication equipment has increased explosively in the information and communication field, such as personal computers and mobile phones. There is a growing need for high-performance, high-frequency electronic components that can be used in

On the other hand, electronic circuit boards tend to generate heat due to the transmission and reception of high-frequency, large-capacity electrical signals associated with information processing, and the amount of power consumed due to the heat generation is becoming impossible to ignore.

In general, the smaller the dielectric loss tangent of the molding material for the electronic circuit board, the lower the amount of heat generated, and the amount of power consumed due to heat generation can be suppressed. As an example focusing on this point, it is known that liquid crystalline aromatic polyester is used as a molding material with a low dielectric loss tangent. For example, Patent Document 1 discloses that the structural unit is composed of a structural unit derived from p-hydroxybenzoic acid and a structural unit derived from 6-hydroxy-2-naphthoic acid, and the content ratio of the structural unit derived from p-hydroxybenzoic acid is Liquid crystalline aromatic polyesters having a composition of approximately 20 to 35 mol % have been proposed.

Patent No. 4363057

However, the liquid crystalline aromatic polyester described in Patent Document 1 is inferior in mechanical strength, particularly Izod impact strength, and further improvement in mechanical strength is required.

It is an object of the present invention to provide a liquid crystal polymer with improved mechanical strength, such as Izod impact strength.

In view of the above-mentioned problems, the present inventors have made extensive studies and have developed molded products with improved mechanical strength by copolymerizing an aliphatic dicarboxylic acid component with a specific structure with other polymerizable monomers. The present inventors have discovered that a liquid crystal polymer that can be formed can be obtained, and have completed the present invention.

That is, the present invention includes the following preferred embodiments.
[1] Formula (1)
HOOC-(CH ₂ ) _n -COOH...Formula (1)
[In the formula, n is an integer from 4 to 18]
A structural unit derived from one or more polymerizable compounds (A) selected from the group consisting of compounds represented by and reactive derivatives thereof, and a structural unit derived from a polymerizable monomer (B). A liquid crystal polymer comprising a liquid crystal polymer in which the total amount of structural units derived from the polymerizable compound (A) is 0.01 to 7 mol% based on 100 mol% of all structural units constituting the liquid crystal polymer.
[2] The polymerizable compound (A) has the formula (2)
HOOC-(CH ₂ ) ₈ -COOH...Formula (2)
The liquid crystal polymer according to [1], which is a compound represented by:
[3] The polymerizable monomer (B) is selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines, and aliphatic diols. The liquid crystal polymer according to [1] or [2], which is one or more selected types.
[4] The liquid crystal polymer according to any one of [1] to [3], wherein the polymerizable monomer (B) contains an aromatic hydroxycarboxylic acid.
[5] The liquid crystal polymer according to any one of [1] to [3], wherein the polymerizable monomer (B) contains an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and an aromatic diol.
[6] The liquid crystal polymer according to any one of [3] to [5], wherein the aromatic hydroxycarboxylic acid is 4-hydroxybenzoic acid and/or 6-hydroxy-2-naphthoic acid.
[7] The liquid crystal polymer according to any one of [3] to [6], wherein the aromatic dicarboxylic acid is one or more selected from the group consisting of terephthalic acid, isophthalic acid, and 2,6-naphthalene dicarboxylic acid. .
[8] The aromatic diol is one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene, according to any one of [3] to [7]. liquid crystal polymer.
[9] The liquid crystal polymer according to [1] or [2], wherein the polymerizable monomer (B) is 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid.
[10] The liquid crystal according to [1] or [2], wherein the polymerizable monomer (B) is 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, aromatic dicarboxylic acid, and aromatic diol. polymer.
[11] A liquid crystal polymer composition comprising the liquid crystal polymer according to any one of [1] to [10] and an inorganic or organic filler.
[12] An article made of a molded article, film, or fiber produced by processing the liquid crystal polymer according to any one of [1] to [10] or the liquid crystal polymer composition according to [11].

According to the liquid crystal polymer of the present invention, articles such as molded articles having improved mechanical strength such as Izod impact strength can be formed.

The liquid crystal polymer of the invention is preferably a polyester or polyester amide that forms an anisotropic melt phase. These are commonly referred to in the art as thermotropic liquid crystal polyesters or thermotropic liquid crystal polyester amides, but are not particularly limited.

The liquid crystal polymer of the present invention has the formula (1)
HOOC-(CH ₂ ) _n -COOH...Formula (1)
[In the formula, n is an integer from 4 to 18]
The total amount of structural units derived from one or more polymerizable compounds (A) (hereinafter also referred to as "aliphatic dicarboxylic acid compounds") selected from the group consisting of the compounds represented by and their reactive derivatives. , 0.01 to 7 mol% based on 100 mol% of all structural units constituting the liquid crystal polymer.

Examples of the compound represented by formula (1) include hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, and pentadecanedioic acid. acids, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, and the like.

Among these, decanedioic acid (sebacic acid), hexanedioic acid (adipic acid) and dodecanedioic acid, which are represented by the following formulas (2) to (4), respectively, have a higher effect of improving mechanical strength. is preferred, and decanedioic acid (sebacic acid) is particularly preferred.

HOOC-(CH ₂ ) ₈ -COOH...Formula (2)
HOOC-(CH ₂ ) ₄ -COOH...Formula (3)
HOOC-(CH ₂ ) ₁₀ -COOH...Formula (4)

The total amount of one or more polymerizable compounds (A) selected from the group consisting of compounds represented by formula (1) and reactive derivatives thereof used to obtain the liquid crystal polymer of the present invention is It corresponds to the total amount of structural units derived from the polymerizable compound (A) contained in the polymerizable compound (A). The total amount of the polymerizable compound (A) used, that is, the total amount of structural units derived from the polymerizable compound (A) contained in the liquid crystal polymer, is the total amount of the polymerizable compound and polymerizable monomer used, that is, the liquid crystal polymer. It is 0.01 to 7 mol%, preferably 0.05 to 5 mol%, more preferably 0.07 to 4 mol%, and even more preferably is 0.1 to 3 mol%. When the total amount of the structural units derived from the polymerizable compound (A) exceeds 7 mol% based on 100 mol% of all the structural units constituting the liquid crystal polymer, heat resistance and mechanical properties deteriorate. If the total amount of structural units derived from the polymerizable compound (A) is less than 0.01 mol% with respect to 100 mol% of all structural units constituting the liquid crystal polymer, mechanical properties such as Izod impact strength may deteriorate. No improvement effect can be obtained.

As the polymerizable monomer (B) used to obtain the liquid crystal polymer of the present invention, monomers used for conventional liquid crystal polymers, such as aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic Mention may be made of aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines and aliphatic diols. These compounds may be used alone or in combination of two or more, but it is desirable to use at least one monomer having a hydroxy group or an amino group.

The polymerizable monomer (B) used to obtain the liquid crystal polymer of the present invention may be an oligomer formed by bonding one or more of the above compounds to each other. In addition, regarding the amount of the polymerizable monomer (B) in this specification and the claims, even if the polymerizable monomer is an oligomer, the amount of the polymerizable monomer (B) is determined depending on the monomer unit constituting the oligomer. The calculation shall be based on

Specific examples of aromatic hydroxycarboxylic acids include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 6-hydroxy-1-naphthoic acid, and 7-hydroxybenzoic acid. -2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 7-hydroxy-1-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxy Examples include phenyl-3-benzoic acid and alkyl, alkoxy or halogen substituted products thereof, and ester-forming derivatives thereof such as acylated products, ester derivatives and acid halides. Among these, 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or a combination thereof is more preferred in that the heat resistance, mechanical strength, and melting point of the resulting liquid crystal polymer can be easily controlled.

Specific examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4'-dicarboxybiphenyl, 3 ,4'-dicarboxybiphenyl and 4,4'-dicarboxyterphenyl, alkyl, alkoxy or halogen substituted products thereof, and ester-forming derivatives thereof such as ester derivatives and acid halides.

Among these, one or more selected from the group consisting of terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid is preferably used.

Specific examples of aromatic diols include hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, Examples include ester-forming derivatives such as 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenol ether, and 2,2'-dihydroxybinaphthyl, alkyl, alkoxy or halogen substituted products thereof, and acylated products thereof.

Among these, one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene is preferably used. ,4'-dihydroxybiphenyl is preferred.

Specific examples of aromatic aminocarboxylic acids include 4-aminobenzoic acid, 3-aminobenzoic acid, 6-amino-2-naphthoic acid, alkyl, alkoxy or halogen substituted products thereof, and acylated products and ester derivatives thereof. and ester-forming derivatives such as acid halides.

Specific examples of aromatic hydroxyamines include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino- 4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenylmethane, 4-amino-4'-hydroxybiphenyl sulfide and 2,2'-diaminobinaphthyl, alkyl thereof , alkoxy or halogen substituted products, and ester-forming derivatives such as acylated products thereof. Among these, 4-aminophenol is preferably used because it is easy to balance the heat resistance and mechanical strength of the resulting liquid crystal polymer.

Specific examples of aromatic diamines include 1,4-phenylenediamine, 1,3-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, alkyl, alkoxy or halogen substituted products thereof, and their Examples include amide-forming derivatives such as acylated products.

Specific examples of aliphatic diols include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and acylated products thereof. In addition, polymers containing aliphatic diol units such as polyethylene terephthalate and polybutylene terephthalate can be combined with the above-mentioned aromatic oxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, and their acylated products, ester derivatives, acid halides, etc. You may react.

The polymerizable monomer (B) is selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines, and aliphatic diols. Using two or more types of compounds in combination is one of the preferred embodiments of the present invention.

Among these polymerizable monomers, combinations containing aromatic hydroxycarboxylic acids, and combinations containing aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, and aromatic diols are preferably used.

Among these, combinations in which the polymerizable monomer (B) is 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, aromatic dicarboxylic acid Combinations of acids and aromatic diols are particularly preferably used.

Specific examples of the polymerizable monomer (B) used in the liquid crystal polymer of the present invention include those consisting of the following combinations:
1) 4-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid copolymer 2) 4-hydroxybenzoic acid/terephthalic acid/4,4'-dihydroxybiphenyl copolymer 3) 4-hydroxybenzoic acid/terephthalic acid /isophthalic acid/4,4'-dihydroxybiphenyl copolymer 4) 4-hydroxybenzoic acid/terephthalic acid/isophthalic acid/4,4'-dihydroxybiphenyl/hydroquinone copolymer 5) 4-hydroxybenzoic acid/terephthalic acid /hydroquinone copolymer 6) 4-hydroxybenzoic acid/terephthalic acid/4,4'-dihydroxybiphenyl/hydroquinone copolymer 7) 6-hydroxy-2-naphthoic acid/terephthalic acid/hydroquinone copolymer 8) 4- Hydroxybenzoic acid/6-hydroxy-2-naphthoic acid/terephthalic acid/4,4'-dihydroxybiphenyl copolymer9) 6-hydroxy-2-naphthoic acid/terephthalic acid/4,4'-dihydroxybiphenyl copolymer 10) 4-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid/terephthalic acid/hydroquinone copolymer 11) 4-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid/terephthalic acid/hydroquinone/4,4' -Dihydroxybiphenyl copolymer 12) 4-hydroxybenzoic acid/2,6-naphthalene dicarboxylic acid/4,4'-dihydroxybiphenyl copolymer 13) 4-hydroxybenzoic acid/terephthalic acid/2,6-naphthalene dicarboxylic acid / Hydroquinone copolymer 14) 4-Hydroxybenzoic acid / 2,6-naphthalene dicarboxylic acid / Hydroquinone copolymer 15) 4-Hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalene dicarboxylic acid / Hydroquinone copolymer 16) 4-hydroxybenzoic acid/terephthalic acid/2,6-naphthalene dicarboxylic acid/hydroquinone/4,4'-dihydroxybiphenyl copolymer 17) 4-hydroxybenzoic acid/terephthalic acid/4-aminophenol Copolymer 18) 6-hydroxy-2-naphthoic acid/terephthalic acid/4-aminophenol copolymer 19) 4-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid/terephthalic acid/4-aminophenol copolymer Coalescence 20) 4-hydroxybenzoic acid/terephthalic acid/4,4'-dihydroxybiphenyl/4-aminophenol copolymer 21) 4-hydroxybenzoic acid/terephthalic acid/ethylene glycol copolymer 22) 4-hydroxybenzoic acid /terephthalic acid/4,4'-dihydroxybiphenyl/ethylene glycol copolymer 23) 4-hydroxybenzoic acid/6-hydroxy-2-naphthoic acid/terephthalic acid/ethylene glycol copolymer 24) 4-hydroxybenzoic acid/ 6-hydroxy-2-naphthoic acid/terephthalic acid/4,4'-dihydroxybiphenyl/ethylene glycol copolymer 25) 4-hydroxybenzoic acid/terephthalic acid/2,6-naphthalene dicarboxylic acid/4,4'-dihydroxy Biphenyl copolymer.

The above liquid crystal polymers may be used alone, or two or more of them may be blended to form the liquid crystal polymer of the present invention.

In a more preferred embodiment of the liquid crystal polymer of the present invention, one or more polymerizable compounds (A) selected from the group consisting of compounds represented by formula (1) and reactive derivatives thereof, and 4-hydroxy A liquid crystal polymer composed of a structural unit derived from benzoic acid and a structural unit derived from 6-hydroxy-2-naphthoic acid is preferred.

In this case, the structural units derived from the polymerizable compound (A) are 0.01 to 7 mol%, and the structural units derived from 4-hydroxybenzoic acid are 50% to 100 mol% of the total structural units constituting the liquid crystal polymer. It is preferable that the structural units derived from the 6-hydroxy-2-naphthoic acid polymerizable monomer account for 10 to 50 mol%.

The content of the structural unit derived from 4-hydroxybenzoic acid is preferably 60 to 88 mol%, more preferably 65 to 85 mol%, and still more preferably 70 to 80 mol%.

Further, the content of the structural unit derived from 6-hydroxy-2-naphthoic acid is preferably 12 to 40 mol%, more preferably 15 to 35 mol%, and even more preferably 20 to 30 mol%.

The method for producing the liquid crystal polymer of the present invention will be described below.

The liquid crystal polymer of the present invention comprises one or more polymerizable compounds (A) selected from the group consisting of compounds represented by formula (1) and reactive derivatives thereof, and a polymerizable monomer (B). It is a liquid crystal polymer made by polymerizing. There are no particular limitations on the method for producing the liquid crystal polymer of the present invention, and the polymerizable compound (A) selected from the group consisting of diol compounds and their reactive derivatives and the polymerizable monomer (B) are combined with an ester bond or The liquid crystal polymer of the present invention can be obtained by subjecting it to a known polycondensation method for forming an amide bond, such as a melt acidolysis method or a slurry polymerization method.

Melt acidolysis is a preferred method for producing the liquid crystal polymers of the present invention. In this method, the polymerizable compound and/or monomer are first heated to form a molten solution of the reactants, and then a polycondensation reaction is continued to obtain a molten polymer. Note that a vacuum may be applied to facilitate the removal of volatile by-products (eg, acetic acid, water, etc.) in the final stage of condensation.

Slurry polymerization is a method in which polymerizable compounds and/or polymerizable monomers are reacted in the presence of a heat exchange fluid, and a solid product is obtained in a suspended state in the heat exchange medium.

In both the melt acidolysis method and the slurry polymerization method, the polymerizable compound (A) and polymerizable monomer (B) used in producing the liquid crystal polymer both have hydroxyl groups and It can also be subjected to the reaction as a modified form in which the amino group is acylated, that is, a lower acylated product.

The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3 carbon atoms. Particularly preferred is a method in which an acetylated product of the polymerizable compound and/or polymerizable monomer is used in the reaction.

The lower acylated product of the polymerizable compound and/or the polymerizable monomer may be acylated separately and synthesized in advance, or the polymerizable compound and/or the polymerizable monomer may be anhydrous during production of the liquid crystal polymer. It can also be produced within the reaction system by adding an acylating agent such as acetic acid.

In either the melt acidolysis method or the slurry polymerization method, the polymerization reaction is preferably carried out at a temperature of 150 to 400°C, preferably 250 to 370°C, under normal pressure and/or reduced pressure, and a catalyst is optionally used. may also be used.

Specific examples of catalysts include organotin compounds such as dialkyltin oxide (e.g. dibutyltin oxide), diaryltin oxide; titanium dioxide; antimony trioxide; organotitanium compounds such as alkoxytitanium silicates, titanium alkoxides; alkalis and alkalis of carboxylic acids. Gaseous acid catalysts such as earth metal salts (for example, potassium acetate); Lewis acids (for example, boron trifluoride), hydrogen halides (for example, hydrogen chloride), and the like.

When a catalyst is used, the amount of the catalyst is preferably 1 to 1000 ppm, more preferably 2 to 100 ppm, based on the total amount of polymerizable monomer (B).

The liquid crystal polymer of the present invention obtained by polycondensation reaction in this manner is usually extracted from the polymerization reaction tank in a molten state and then processed into pellets, flakes, or powder.

Liquid crystal polymers in the form of pellets, flakes, or powders are made into a substantially solid state under reduced pressure, vacuum, or an inert gas atmosphere such as nitrogen or helium, in order to increase the molecular weight and improve heat resistance. Heat treatment may be performed in this state.

The liquid crystal polymer of the present invention obtained as described above is blended with one or more selected from inorganic or organic fillers, other additives explained below, and other resin components to form a liquid crystal polymer. It may also be used as a composition.

The inorganic or organic filler that may be incorporated into the liquid crystal polymer of the present invention may be fibrous, plate-like or granular, such as glass fiber, milled glass, silica alumina fiber, alumina fiber, carbon fiber, aramid. These include fibers, potassium titanate whiskers, aluminum borate whiskers, wollastonite, talc, mica, graphite, calcium carbonate, dolomite, clay, glass flakes, glass beads, barium sulfate, and titanium oxide. Among these, glass fiber is preferable because it has an excellent balance between physical properties and cost. Two or more of these fillers may be used in combination.

The total amount of inorganic or organic fillers in the liquid crystal polymer composition of the present invention is preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polymer. If the total amount of the inorganic or organic filler exceeds 200 parts by mass based on 100 parts by mass of the liquid crystal polymer, the moldability of the liquid crystal polymer composition tends to decrease, and the moldability of the cylinder or mold of the molding machine tends to deteriorate. There is a tendency for wear to increase.

The liquid crystal polymer of the present invention may contain other additives, such as higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts (here, higher fatty acids are usually carbon mold release improvers such as polysiloxanes and fluororesins; colorants such as dyes and pigments; antioxidants; heat stabilizers; ultraviolet absorbers; antistatic agents; surfactants etc. may be blended. These additives may be used alone or in combination of two or more.

The total amount of other additives in the liquid crystal polymer composition of the present invention is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the liquid crystal polymer. If the total amount of other additives exceeds 10 parts by mass based on 100 parts by mass of the liquid crystal polymer, the moldability of the liquid crystal polymer composition tends to decrease and the thermal stability tends to deteriorate.

In addition, when molding the liquid crystal polymer or liquid crystal polymer composition of the present invention, among the other additives mentioned above, additives having an external lubricant effect such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon surfactants may be used. may be attached to the surface of the liquid crystal polymer pellet in advance.

The liquid crystal polymer of the present invention may contain other resin components. Examples of other resin components include polyamides, polyesters, polyolefins, polyacetals, polyphenylene ethers, and modified products thereof, thermoplastic resins such as polysulfone, polyethersulfone, polyetherimide, polyamideimide, phenolic resins, epoxy resins, Examples include thermosetting resins such as polyimide resins. Other resin components can be blended alone or in combination of two or more. The blending amount of other resin components is not particularly limited, and may be determined as appropriate depending on the use and purpose of the liquid crystal polymer. In one typical example, the total amount of other resin components is usually 0.1 to 100 parts by weight, particularly 0.5 to 80 parts by weight, based on 100 parts by weight of the liquid crystal polymer.

The melt viscosity of the liquid crystal polymer of the present invention is preferably 1 to 300 Pa·s, more preferably 5 ^to 100 Pa·s, even more preferably 10 ~50 Pa・s. Note that the lower the melt viscosity, the better the fluidity during molding.

The liquid crystal polymer composition of the present invention is produced by adding inorganic or organic fillers, other additives, other resin components, etc. to a liquid crystal polymer, and then using a Banbury mixer, kneader, single screw or twin screw extruder, etc. It can be obtained by melting and kneading in a temperature range from near the crystal melting temperature of the liquid crystal polymer to 100° C. above the crystal melting temperature.

The liquid crystal polymer or liquid crystal polymer composition of the present invention thus obtained is processed into articles such as molded articles, films, or fibers by known processing methods such as injection molding, compression molding, extrusion molding, and blow molding.

The liquid crystal polymer or liquid crystal polymer composition of the present invention has improved mechanical strength such as Izod impact strength, and preferably has excellent mechanical properties, and is therefore particularly useful as electrical/electronic parts, mechanical mechanism parts, automobile parts, etc.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

Melt viscosity, tensile strength, bending strength and Izod impact strength in Examples were measured by the methods described below.

(1) Melt viscosity It was measured at 350° C. using a melt viscosity measuring device (Capillograph 1D manufactured by Toyo Seiki Co., Ltd.) using a 0.7 mmφ×10 mm capillary at a shear rate of 1000 sec ⁻¹ .

(2) Tensile strength Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), an ASTM No. 4 dumbbell test piece was molded at a cylinder temperature of 350°C and a mold temperature of 70°C. Measured according to ASTM D638.

(3) Bending strength Injection molding was performed using an injection molding machine (MINIMAT M26/15 manufactured by Sumitomo Heavy Industries, Ltd.) with a mold clamping pressure of 15 tons at a cylinder temperature setting of 350°C and a mold temperature of 70°C, and a strip test was performed. A piece (length 65 mm x width 12.7 mm x thickness 2.0 mm) was produced. The bending test was a three-point bending test using INSTRON 5567 (a universal testing machine manufactured by Instron Japan Company Limited) in accordance with ASTM D790, with a span distance of 40.0 mm and a compression speed of 1.3 mm/min.

(4) Izod impact strength Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), the cylinder temperature was set at 350°C, the mold temperature was 70°C, and the length was 127.0 mm, the width was 12.7 mm, and the thickness was 127.0 mm. A rectangular test piece with a length of 3.2 mm was molded. The center of this test piece was cut perpendicularly to the length direction to obtain a strip-shaped test piece with a length of 63.5 mm, a width of 12.7 mm, and a thickness of 3.2 mm, and measurements were made in accordance with ASTM D256.

In the Examples, the following abbreviations indicate the following compounds.
POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid HQ: Hydroquinone BP: 4,4'-dihydroxybiphenyl TPA: Terephthalic acid NDA: 2,6-naphthalene dicarboxylic acid

Moreover, the following were used as the polymerizable compound (A) (aliphatic dicarboxylic acid compound).
A1: HOOC-(CH ₂ ) ₈ -COOH (sebacic acid)
A2: HOOC-(CH ₂ ) ₄ -COOH (adipic acid)
A3: HOOC-(CH ₂ ) ₁₀ -COOH (dodecanedioic acid)

[Example 1]
The following compounds were charged into a reaction vessel equipped with a stirring device equipped with a torque meter and a distillation tube, and acetic anhydride was added in an amount of 1.03 times the hydroxyl group amount (mol) of all monomers, and decomposition was carried out under the following conditions. Acetic acid polymerization was performed.
Sebacic acid: 13.1g (1.0 mol%)
POB: 650.9g (72.5 mol%)
BON6: 324.1g (26.5 mol%)

The temperature was raised from room temperature to 150° C. in 1 hour under a nitrogen gas atmosphere, and maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210° C. while distilling off the by-produced acetic acid, and the temperature was maintained at the same temperature for 30 minutes. Thereafter, the temperature was raised to 325° C. over 5 hours, and then the pressure was reduced to 20 mmHg over 90 minutes. The polymerization reaction was terminated when a predetermined torque was exhibited, the contents of the reaction vessel were taken out, and pellets of liquid crystal polymer were obtained using a pulverizer. The amount of acetic acid distilled during the polymerization was almost the same as the theoretical value. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Examples 2-5, Comparative Examples 1-2]
Liquid crystal polymer pellets were obtained in the same manner as in Example 1, except that the polymerizable compound (A) (aliphatic dicarboxylic acid compound), POB and BON6 were used in the proportions (mol%) shown in Table 1. Ta. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Example 6]
The following compounds were charged into a reaction vessel equipped with a stirring device equipped with a torque meter and a distillation tube, and acetic anhydride was added in an amount of 1.03 times the hydroxyl group amount (mol) of all monomers, and decomposition was carried out under the following conditions. Acetic acid polymerization was performed.
Sebacic acid: 13.1g (1.0 mol%)
POB: 390.5g (43.5 mol%)
BON6: 194.5g (15.9 mol%)
HQ: 141.7g (19.8 mol%)
TPA: 213.8g (19.8 mol%)

The temperature was raised from room temperature to 150° C. in 1 hour under a nitrogen gas atmosphere, and maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210° C. while distilling off the by-produced acetic acid, and the temperature was maintained at the same temperature for 30 minutes. Thereafter, the temperature was raised to 345° C. over 5 hours, and then the pressure was reduced to 20 mmHg over 90 minutes. The polymerization reaction was terminated when a predetermined torque was exhibited, the contents of the reaction vessel were taken out, and pellets of liquid crystal polymer were obtained using a pulverizer. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Comparative example 3]
Liquid crystal polymer pellets were obtained in the same manner as in Example 6, except that the charged compounds were changed as follows. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.
POB: 395.0g (44.0 mol%)
BON6: 195.7g (16.0 mol%)
HQ: 143.1g (20.0mol%)
TPA: 216.0g (20.0mol%)

[Example 7]
The following compounds were charged into a reaction vessel equipped with a stirring device equipped with a torque meter and a distillation tube, and acetic anhydride was added in an amount of 1.03 times the hydroxyl group amount (mol) of all monomers, and decomposition was carried out under the following conditions. Acetic acid polymerization was performed.
Sebacic acid: 13.1g (1.0 mol%)
POB: 317.8g (35.4 mol%)
BON6: 48.9g (4.0mol%)
HQ: 113.8g (15.9 mol%)
BP: 168.2g (13.9 mol%)
TPA: 321.8g (29.8 mol%)

The temperature was raised from room temperature to 145° C. in 1 hour under a nitrogen gas atmosphere, and maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210° C. while distilling off the by-produced acetic acid, and the temperature was maintained at the same temperature for 30 minutes. Thereafter, the temperature was raised to 350° C. over 7 hours, and then the pressure was reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined torque was exhibited, the contents of the reaction vessel were taken out, and pellets of liquid crystal polymer were obtained using a pulverizer. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Comparative example 4]
Liquid crystal polymer pellets were obtained in the same manner as in Example 7, except that the charged compounds were changed as follows. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.
POB: 323.2g (36.0 mol%)
BON6: 48.9g (4.0mol%)
HQ: 114.5g (16.0mol%)
BP: 169.5g (14.0 mol%)
TPA: 324.0g (30.0 mol%)

[Example 8]
The following compounds were charged into a reaction vessel equipped with a stirring device equipped with a torque meter and a distillation tube, and acetic anhydride was added in an amount of 1.03 times the hydroxyl group amount (mol) of all monomers, and decomposition was carried out under the following conditions. Acetic acid polymerization was performed.
Sebacic acid: 13.1g (1.0 mol%)
POB: 634.7g (70.7mol%)
BON6: 30.6g (2.5 mol%)
HQ: 92.3g (12.9 mol%)
NDA: 181.3g (12.9mol%)

The temperature was raised from room temperature to 145° C. in 1 hour under a nitrogen gas atmosphere, and maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210° C. while distilling off the by-produced acetic acid, and the temperature was maintained at the same temperature for 30 minutes. Thereafter, the temperature was raised to 345° C. over 7 hours, and then the pressure was reduced to 10 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined torque was exhibited, the contents of the reaction vessel were taken out, and pellets of liquid crystal polymer were obtained using a pulverizer. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Comparative example 5]
Liquid crystal polymer pellets were obtained in the same manner as in Example 8, except that the charged compounds were changed as follows. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.
POB: 641.9g (71.5 mol%)
BON6: 30.6g (2.5 mol%)
HQ: 93.0g (13.0 mol%)
NDA: 182.7g (13.0 mol%)

[Example 9]
The following compounds were charged into a reaction vessel equipped with a stirring device equipped with a torque meter and a distillation tube, and acetic anhydride was added in an amount of 1.03 times the hydroxyl group amount (mol) of all monomers, and decomposition was carried out under the following conditions. Acetic acid polymerization was performed.
Sebacic acid: 13.1g (1 mol%)
BON6: 653.2g (53.4 mol%)
HQ: 14.3g (2.0 mol%)
BP: 251.8g (20.8 mol%)
TPA: 246.2g (22.8 mol%)

The temperature was raised from room temperature to 145°C over 1 hour under a nitrogen gas atmosphere, and maintained at 145°C for 30 minutes. Next, the temperature was raised to 350° C. over 7 hours while distilling by-product acetic acid, and then the pressure was reduced to 5 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined stirring torque was obtained, the contents were taken out from the reaction vessel, and pellets of liquid crystal polymer were obtained using a crusher. The amount of acetic acid distilled during the polymerization was almost the same as the theoretical value. Using the obtained pellets, melt viscosity, tensile strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.

[Comparative example 6]
Liquid crystal polymer pellets were obtained in the same manner as in Example 8, except that the charged compounds were changed as follows. Using the obtained pellets, melt viscosity, tensile strength, bending strength and Izod impact strength were measured by the above methods. The results are shown in Table 1.
BON6: 660.5g (54.0 mol%)
HQ: 14.3g (2.0mol%)
BP: 254.2g (21.0 mol%)
TPA: 248.4g (23.0 mol%)

As shown in Table 1, the liquid crystal polymers of the present invention containing specific aliphatic dicarboxylic acids (Examples 1 to 9) were compared with the liquid crystal polymers not containing them (Comparative Examples 1 to 6), respectively. It is understood that the mechanical properties such as tensile strength, bending strength and Izod impact strength are also improved, and there is an effect of improving mechanical strength.

Claims (4)

Formula (1)
HOOC-(CH ₂ ) _n -COOH...Formula (1)
[In the formula, n is an integer from 4 to 18]
A structural unit derived from one or more polymerizable compounds (A) selected from the group consisting of compounds represented by and reactive derivatives thereof, and a structural unit derived from a polymerizable monomer (B). The total amount of structural units derived from the polymerizable compound (A) is 0.01 to 7 mol% with respect to 100 mol% of all structural units forming the liquid crystal polymer,
The polymerizable monomer (B) is the following (i) to (iii)
(i) 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid,
(ii) 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, aromatic dicarboxylic acids and aromatic diols, where aromatic dicarboxylic acids are selected from terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid; The aromatic diol is one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene.
(iii) 6-hydroxy-2-naphthoic acid, an aromatic dicarboxylic acid and an aromatic diol, where the aromatic dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid. The aromatic diol is one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene .
A liquid crystal polymer selected from the group consisting of . The polymerizable compound (A) has the formula (2)
HOOC-(CH ₂ ) ₈ -COOH...Formula (2)
The liquid crystal polymer according to claim 1, which is a compound represented by: A liquid crystal polymer composition comprising the liquid crystal polymer according to any one of claims 1 to 2 and an inorganic or organic filler. An article made of a molded article, film, or fiber produced by processing the liquid crystal polymer according to any one of claims 1 to 2 or the liquid crystal polymer composition according to claim 3 .