JP6426994B2 - Method for producing liquid crystal polymer - Google Patents

Description

  The present invention relates to a method of producing a liquid crystal polymer with less loss of raw material.

  Thermotropic liquid crystal polymers (hereinafter referred to as liquid crystal polymers or LCP) have excellent heat resistance, mechanical properties such as rigidity, chemical resistance, dimensional accuracy, etc. Its use is expanding to applications.

  The liquid crystal polymer is obtained by polycondensing monomers selected from aromatic diols, aromatic dicarboxylic acids, aromatic hydroxycarboxylic acids, etc., in combination according to the physical properties of the liquid crystal polymer to be used. It is

  As a method for producing a liquid crystal polymer, a melt acidolysis method in which a heat exchange fluid is not reacted is known, and in this melt acidolysis method, a monomer is heated to form a melt of a reaction substance, and then By carrying out the polymerization reaction, a molten polymer is obtained.

  Under the present circumstances, the method of using for polymerization reaction is generally performed, after pre-acylating the mixture of a monomer with an acetic anhydride. The mixture of acylated monomers performs a polymerization reaction in the molten state while distilling off acetic acid, but the diacetate of an aromatic diol which is an acylated product of an aromatic diol used as a raw material is very easily sublimated Therefore, it is easy to distill off from the reaction vessel together with acetic acid.

  For this reason, conventionally, the balance of the functional groups in the liquid crystal polymer has been adjusted by increasing the amount of aromatic diol in the raw material more than necessary. However, in this method, the amount of raw materials is increased, and there is a problem that the sublimate adheres to the reaction tank.

  Moreover, although the method of suppressing sublimation of hydroquinone is disclosed by patent document 1 in the process of distilling an acetic acid by starting pressure reduction by acetic acid distillation rate 90% or more, the process of distilling an acetic acid It takes time to reduce the productivity.

  Therefore, a method for producing a liquid crystal polymer in which the loss of aromatic diol is reduced is desired.

JP 2012-149241 A

  An object of the present invention is to provide a method for producing a liquid crystal polymer with less loss of raw material.

  As a result of intensive studies on a method of suppressing sublimation of an aromatic diol at the time of polymerization of a liquid crystal polymer, the present inventors previously esterified an aromatic diol with an aromatic hydroxycarboxylic acid to polymerize the liquid crystal polymer. It has been found that sublimation at time is suppressed, and the present invention has been completed.

  Since the method for producing a liquid crystal polymer of the present invention uses a monomer excellent in sublimation resistance, it is possible to reduce the loss of the raw material due to sublimation, and the reaction tank is not contaminated due to the adhesion of the sublimate. It can improve stability.

  The liquid crystal polymer produced by the method of the present invention is a polyester or polyesteramide that forms an anisotropic melt phase, and is not particularly limited as long as it is called a thermotropic liquid crystal polyester or a thermotropic liquid crystal polyesteramide in the art. .

  The properties of the anisotropic melt phase can be confirmed by a conventional polarization inspection method using crossed polarizers. More specifically, confirmation of the anisotropic melt phase can be performed by observing the sample mounted on the Leitz hot stage under a nitrogen atmosphere at a magnification of 40 using a Leitz polarization microscope. The liquid crystal polymers of the present invention are optically anisotropic, i.e., they transmit light when inspected between crossed polarizers. If the sample is optically anisotropic, it will transmit polarized light, even in the quiescent state.

で表される化合物およびその反応性誘導体からなる群から選択される。上記式（１）で表される化合物としては、具体的には４−ヒドロキシ安息香酸４−ヒドロキシフェニルエステル、４−ヒドロキシ安息香酸６−ヒドロキシナフチル−２−イルエステル、４−ヒドロキシ安息香酸４’−ヒドロキシビフェニル−４−イルエステル、６−ヒドロキシ−２−ナフトエ酸４−ヒドロキシフェニルエステル、６−ヒドロキシ−２−ナフトエ酸６−ヒドロキシナフチル−２−イルエステル、６−ヒドロキシ−２−ナフトエ酸４’−ヒドロキシビフェニル−４−イルエステルが挙げられ、液晶ポリマーの耐熱性および機械強度ならびに融点を調節し易いという点や重合時の反応性に優れる点から４−ヒドロキシ安息香酸４−ヒドロキシフェニルエステルおよび６−ヒドロキシ−２−ナフトエ酸４−ヒドロキシフェニルエステルが好ましい。 The polymerizable monomer (A) used in the method of the present invention has the formula (1):

It is selected from the group consisting of a compound represented by and its reactive derivative. Specific examples of the compound represented by the above formula (1) include 4-hydroxybenzoic acid 4-hydroxyphenyl ester, 4-hydroxybenzoic acid 6-hydroxynaphthyl-2-yl ester, 4-hydroxybenzoic acid 4 ′ -Hydroxybiphenyl-4-yl ester, 6-hydroxy-2-naphthoic acid 4-hydroxyphenyl ester, 6-hydroxy-2-naphthoic acid 6-hydroxynaphthyl-2-yl ester, 6-hydroxy-2-naphthoic acid 4 4-hydroxybenzoic acid 4-hydroxyphenyl ester from the viewpoints of the heat resistance and mechanical strength of the liquid crystal polymer and the ease of adjusting the melting point and the excellent reactivity during polymerization 6-Hydroxy-2-naphthoic acid 4-hydroxyphenyl ester Preferred.

  The compound represented by the formula (1) may be produced by esterifying an aromatic diol and an aromatic hydroxycarboxylic acid using a method known to those skilled in the art, and the production method thereof is For example, the method described in Unexamined-Japanese-Patent No. 2012-201603 is mentioned. Specifically, an aromatic hydroxycarboxylic acid and an aromatic diol are reacted by heating under reflux in a solvent in the presence of sulfuric acid and phosphoric acid, and then sodium hydrogen carbonate is added to purify the precipitated solid. Thus, the compound represented by the formula (1) can be obtained.

  In the present specification, the term "reactive derivative" of a polymerizable monomer refers to a derivative of a monomer having reactivity capable of introducing a target constituent unit. As a reactive derivative of the compound represented by Formula (1) which can be used in the present invention, an alkyl, alkoxy or halogen-substituted compound of the compound represented by Formula (1), an acylated product, an ester derivative, an acid halide And ester forming derivatives such as acyl derivatives, ester derivatives and acid halides of these substituents. As the alkyl group or alkoxy group as a substituent, those having up to 6 carbon atoms are suitably used. As the polymerizable monomer (A) selected from the group consisting of the compound represented by the formula (1) and a reactive derivative thereof, only one type of compound may be used, or a combination of two or more types of compounds may be used. You may use.

  In the present specification, "aromatic" is intended to mean a compound containing an aromatic group having up to 4 condensed rings. Moreover, "aliphatic" shall mean a compound containing a saturated or unsaturated carbon chain having 2 to 12 carbon atoms, which may have a branch.

  The total amount of the polymerizable monomer (A) selected from the group consisting of the compound represented by the formula (1) and its reactive derivative used in the method of the present invention depends on the characteristics of the liquid crystal polymer to be targeted The amount is preferably 50 mol parts or less, more preferably 45 mol parts or less, and 10 to 40 mol parts, per 100 mol parts of the total amount of other polymerizable monomers (B). More preferable. If the total amount of the polymerizable monomers (A) exceeds 50 parts by mole with respect to 100 parts by weight of the total amount of the other polymerizable monomers (B), the polymerizability of the liquid crystal polymer tends to decrease.

  In the present invention, all of the aromatic diols used can be used as compounds represented by the formula (1) by esterifying beforehand with aromatic hydroxycarboxylic acids. Further, a part of the aromatic diol to be used is preliminarily esterified with an aromatic hydroxycarboxylic acid to obtain a compound represented by the formula (1), and the remaining aromatic diol is used as it is with other polymerizable monomers ( It can also be used as B). In the present invention, 50% or more, preferably 70% or more, more preferably 90% or more, more preferably all of the aromatic diol used is represented by the formula (1) by esterifying in advance with an aromatic hydroxycarboxylic acid. It is preferable to use as a compound.

  As the other polymerizable monomer (B) used in the method of the present invention, monomers used for conventional liquid crystal polymers, such as aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic aminocarboxylic acid Acids, aromatic hydroxyamines, aromatic diamines, aliphatic diols and aliphatic dicarboxylic acids are included. These compounds may use only 1 type and may combine 2 or more types.

  Specific examples of the aromatic hydroxycarboxylic acid include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 2-hydroxy-5-naphthoic acid, 2-hydroxybenzoic acid 7-naphthoic acid, 2-hydroxy-3-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid and their Examples thereof include alkyl, alkoxy or halogen substituents as well as ester-forming derivatives such as acyl derivatives, ester derivatives and acid halides thereof. Among these, using 4-hydroxybenzoic acid or 2-hydroxy-6-naphthoic acid alone or in combination is more preferable in that the heat resistance and mechanical strength and melting point of the liquid crystal polymer obtained can be easily adjusted. preferable.

  Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3 4,4′-dicarboxybiphenyl, 4,4′-dicarboxyterphenyl, bis (4-carboxyphenyl) ether, bis (4-carboxyphenoxy) butane, bis (4-carboxyphenyl) ethane, bis (3 -Carboxyphenyl) ethers and bis (3-carboxyphenyl) ethanes, their alkyl, alkoxy or halogen substitutes as well as their ester derivatives, ester forming derivatives such as acid halides and the like. Among these, terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid are suitably used, and terephthalic acid is particularly preferable in that the heat resistance of the liquid crystal polymer obtained can be effectively enhanced.

  Specific examples of the aromatic diol include hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenol ether, bis (4-hydroxyphenyl) ethane and 2,2'-dihydroxybinaphthyl, and their alkyl, alkoxy or halogen substituents, their acylated products, etc. Ester-forming derivatives of Among these, hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl and 2,6-dihydroxynaphthalene are preferably used, and hydroquinone, 4,4'-dihydroxybiphenyl or , 6-dihydroxy naphthalene is preferred. The aromatic diol in the present invention does not include the compound represented by the above formula (1).

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

  Specific examples of the aromatic hydroxyamine 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, their alkyls And alkoxy- or halogen-substituted products, as well as ester-forming derivatives such as their acylated compounds. Among these, 4-aminophenol is preferably used because it is easy to balance the heat resistance and mechanical strength of the liquid crystal polymer from which it is obtained.

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

  Specific examples of aliphatic diols include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and their acylated products. In addition, a polymer containing an aliphatic diol such as polyethylene terephthalate or polybutylene terephthalate is reacted with the above-mentioned aromatic oxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol and their acylated products, ester derivatives, acid halides, etc. You may

  Specific examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and dodecanedioic acid. Among these, oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid and dodecanedioic acid are preferably used because of their excellent reactivity during polymerization.

  The liquid crystal polymer produced by the method of the present invention may contain a thioester bond as long as the object of the present invention is not impaired. Monomers that provide such bonds include mercapto aromatic carboxylic acids, and aromatic dithiols and hydroxy aromatic thiols. The amount of these monomers used is preferably 10 mol parts or less based on the total amount of other polymerizable monomers (B).

  As another polymerizable monomer (B), aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic aminocarboxylic acid, aromatic hydroxyamine, aromatic diamine, aliphatic diol and aliphatic dicarboxylic acid The combined use of two or more compounds selected from the group consisting of is one of the preferred embodiments of the present invention. Among these polymerizable monomers, a combination containing an aromatic hydroxycarboxylic acid is more preferably used, and a combination containing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol is more preferably used.

  The process for producing a liquid crystal polymer of the present invention comprises a polymerizable monomer (A) selected from the group consisting of a compound represented by the formula (1) and a reactive derivative thereof and another polymerizable monomer (B) Is subjected to a known condensation polymerization method for forming an ester bond or an amide bond, such as a melt acidolysis method, a slurry polymerization method and the like.

  Melting acidolysis is a preferred method for producing the liquid crystal polymers of the present invention. In this method, the polymerizable monomer is first heated to form a molten solution of reactants, and then the polycondensation reaction is continued to obtain a molten polymer. A vacuum may be applied to facilitate removal of volatiles (for example, acetic acid, water, etc.) by-produced in the final stage of condensation.

  The slurry polymerization method is a method of reacting in the presence of a heat exchange fluid, and a solid product is obtained in the state of being suspended in a heat exchange medium.

  In any of the melt acidolysis method and the slurry polymerization method, the polymerizable monomer (A) and the other polymerizable monomer (B) used when producing the liquid crystal polymer are all at normal temperature. Alternatively, the hydroxyl group and / or the amino group can be subjected to the reaction as an acylated modified form, ie, a lower acylated product.

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

  The lower acylated product of the polymerizable monomer may be separately acylated and previously synthesized, or may be used in the reaction system by adding an acylating agent such as acetic anhydride to the polymerizable monomer at the time of production of the liquid crystal polymer. It can also be generated by

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

  Specific examples of the catalyst include organotin compounds such as dialkyltin oxide (for example, dibutyltin oxide) and diaryltin oxide; organotitanium compounds such as titanium dioxide, antimony trioxide, alkoxytitanium silicate, and titanium alkoxide; alkalis and alkalis of carboxylic acids And a gaseous acid catalyst such as a rare earth metal salt (eg, potassium acetate); a Lewis acid (eg, boron trifluoride), hydrogen halide (eg, 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, relative to the total amount of other polymerizable monomers (B).

The melt viscosity of the liquid crystal polymer of the present invention is preferably 1 to 1000 Pa · s, more preferably 5 to 300 Pa · s when measured under a condition of a temperature of 320 ° C. and a shear rate of 1000 s ⁻¹ using a capillary rheometer. It is.

  The liquid crystal polymer of the present invention thus obtained by the polycondensation reaction is usually taken out from the polymerization reaction tank in a molten state and then processed into a pellet, flake or powder.

  The pellet, flake, or powder liquid crystal polymer is substantially solid phase under reduced pressure, in vacuum, or under an inert gas atmosphere such as nitrogen or helium for the purpose of increasing molecular weight and improving heat resistance. Heat treatment may be performed in the state.

  The temperature of the heat treatment carried out in the solid phase is not particularly limited as long as the liquid crystal polymer does not melt, but the temperature is preferably 260 to 350 ° C, preferably 280 to 320 ° C.

  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 described below, and other resin components, to obtain a liquid crystal polymer. It may be a composition.

  The inorganic or organic filler that may be incorporated into the liquid crystal polymer produced by the method of the present invention may be fibrous, plate-like or particulate, such as glass fiber, milled glass, silica alumina fiber, alumina fiber Carbon fibers, aramid 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 in that the balance between physical properties and cost is excellent. Two or more of these fillers may be used in combination.

  The total amount of the inorganic or organic filler in the liquid crystal polymer composition is preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight with respect to 100 parts by weight of the liquid crystal polymer. When the total amount of the above inorganic fillers exceeds 200 parts by weight with respect to 100 parts by weight of the liquid crystal polymer, the moldability of the liquid crystal polymer composition tends to decrease, and the cylinder and mold of the molding machine wear out. It tends to grow.

  The liquid crystal polymer produced by the method 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 (where higher fatty acids and the like) as long as the effects of the present invention are not impaired. Represents a carbon number of 10 to 25), polysiloxane, fluorocarbon resin and other release modifiers; dyes such as pigments and colorants; antioxidants; thermal stabilizers; ultraviolet light absorbers; You may mix | blend surfactant etc. These additives may be blended alone or in combination of two or more.

  The total amount of other additives in the liquid crystal polymer composition is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the liquid crystal polymer. When the total amount of the other additives exceeds 10 parts by weight with respect to 100 parts by weight of the liquid crystal polymer, the molding processability of the liquid crystal polymer composition tends to decrease, and the heat stability tends to deteriorate.

  Further, when molding a liquid crystal polymer or a liquid crystal polymer composition produced by the method of the present invention, among the above-mentioned other additives, external lubricants such as higher fatty acid, higher fatty acid ester, higher fatty acid metal salt, fluorocarbon surfactant and the like The additives having effects may be attached to the surface of the liquid crystal polymer pellet in advance.

  Other resin components may be added to the liquid crystal polymer produced by the method of the present invention. Other resin components include, for example, polyamides, polyesters, polyacetals, polyphenylene ethers, and modified products thereof, and thermoplastic resins such as polysulfones, polyethersulfones, polyetherimides, and polyamideimides, phenol resins, epoxy resins, polyimide resins And thermosetting resins. The other resin components can be blended alone or in combination of two or more. The blending amount of the other resin component is not particularly limited, and may be appropriately determined according to the application and purpose of the liquid crystal polymer. In one typical example, the total amount of the other resin components is 0.1 to 100 parts by weight, in particular 0.1 to 80 parts by weight, with respect to 100 parts by weight of the liquid crystal polymer.

  A liquid crystal polymer composition is prepared by adding an inorganic or organic filler, another filler and another resin component to a liquid crystal polymer, and using this in a Banbury mixer, a kneader, a single screw or twin screw extruder, etc. It can be obtained by melt-kneading in the temperature range from the vicinity of the crystal melting temperature of the above to the crystal melting temperature plus 100 ° C.

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

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.

  The characteristic values in the examples were measured by the following methods.

Melt viscosity
Melt viscosity was measured using a 0.7 mmφ × 10 mm capillary with a melt viscosity measurement apparatus (Capirograph 1D manufactured by Toyo Seiki Co., Ltd.).

<Crystal melting temperature>
After measuring the endothermic peak temperature (Tm1) observed when the sample is measured from room temperature to 20 ° C./min using a differential scanning calorimeter (Exstar 6000 manufactured by Seiko Instruments Inc.), 20 from Tm1 The temperature is maintained at a temperature of 50 ° C for 10 minutes. Next, the sample is cooled to room temperature under a temperature drop condition of 20 ° C./min, and an endothermic peak when measured again under a temperature rise condition of 20 ° C./min is observed, and the temperature showing the peak top is the crystal melting temperature (Tm ).

Example 1
The following compounds are charged in a reaction vessel equipped with a stirring blade and a distillation tube, heated to 40 ° C. to 170 ° C. in 1 hour under nitrogen gas atmosphere, maintained at 170 ° C. for 30 minutes, and then to 350 ° C. The temperature was raised over 7 hours, and the mixture was further reacted at 350 ° C. for 10 minutes, and then depressurized at 350 ° C. Then, the pressure was reduced to 10 torr over 1.5 hours, and when the predetermined stirring torque was reached, the polycondensation was completed. The contents were removed from the reaction vessel, and pellets of resin were obtained by a grinder. The amount of acetic acid distilled during polymerization was almost as theoretical. Further, the sublimate adhering to the upper part of the reaction vessel was recovered and the weight was measured to calculate the sublimation rate. The results are shown in Table 1 together with the melt viscosity and the melting point of the resulting resin.
4-hydroxybenzoic acid: 27 molar parts 6-hydroxy-2-naphthoic acid: 20 molar parts 4-hydroxybenzoic acid 4-hydroxyphenyl ester (obtained by esterification of hydroquinone with 4-hydroxybenzoic acid): 27 molar parts Terephthalic acid: 27 molar parts Acetic anhydride: 103 molar parts

Example 2
The following compounds were charged in a reaction vessel equipped with a stirring blade and a distillation tube, and polycondensation was performed in the same manner as in Example 1, and the sublimate was recovered and its weight was measured to calculate the sublimation rate. The results are shown in Table 1 together with the melt viscosity and the melting point of the resulting resin.
4-hydroxybenzoic acid: 47 molar parts 4-hydroxybenzoic acid 4-hydroxyphenyl ester (obtained by esterification of hydroquinone with 4-hydroxybenzoic acid): 6 molar parts 6-hydroxy-2-naphthoic acid 4 -Hydroxyphenyl ester (obtained by esterification of hydroquinone with 6-hydroxy-2-naphthoic acid): 20 molar parts terephthalic acid: 27 molar parts acetic anhydride: 103 molar parts

Comparative Example 1
The following compounds were charged in a reaction vessel equipped with a stirring blade and a distillation tube, and polycondensation was performed in the same manner as in Example 1, and the sublimate was recovered and its weight was measured to calculate the sublimation rate. The results are shown in Table 1 together with the melt viscosity and the melting point of the resulting resin.
4-hydroxybenzoic acid: 42 molar parts 6-hydroxy-2-naphthoic acid: 16 molar parts hydroquinone: 21 molar parts terephthalic acid: 21 molar parts acetic anhydride: 103 molar parts

［式中、Ａｒ _１ とＡｒ _２ は同一であっても異なっていてもよく、Ａｒ _１ はベンゼン環またはナフタレン環であり、Ａｒ _２ はベンゼン環、ナフタレン環およびビフェニル環からなる群から選択される］
〔２〕式（１）で表される化合物が、４−ヒドロキシ安息香酸４−ヒドロキシフェニルエステルおよび／または６−ヒドロキシ−２−ナフトエ酸４−ヒドロキシフェニルエステルである、〔１〕に記載の液晶ポリマーの製造方法。
〔３〕重合性単量体（Ａ）が他の重合性単量体（Ｂ）の合計量１００モル部に対して５０モル部以下である、〔１〕または〔２〕に記載の液晶ポリマーの製造方法。
〔４〕他の重合性単量体（Ｂ）が、芳香族ヒドロキシカルボン酸、芳香族ジカルボン酸、芳香族ジオール、芳香族アミノカルボン酸、芳香族ヒドロキシアミン、芳香族ジアミン、脂肪族ジオールおよび脂肪族カルボン酸からなる群から選択される１種以上の化合物である、〔１〕〜〔３〕のいずれかに記載の液晶ポリマーの製造方法。
〔５〕他の重合性単量体（Ｂ）が芳香族ヒドロキシカルボン酸を含む、〔１〕〜〔４〕のいずれかに記載の液晶ポリマーの製造方法。
〔６〕芳香族ヒドロキシカルボン酸が、４−ヒドロキシ安息香酸および／または２−ヒドロキシ−６−ナフトエ酸である、〔４〕または〔５〕に記載の液晶ポリマーの製造方法。
As shown in Table 1, in Examples 1 and 2 in which hydroquinone which is an aromatic diol is esterified and used, liquid crystals are reduced while reducing the formation of a sublimate as compared with Comparative Example 1 in which hydroquinone is not esterified. It was possible to produce a polymer. Therefore, it is understood that the production method according to the present invention is one in which the loss of the raw material used to produce the liquid crystal polymer is reduced.
Preferred embodiments of the present invention include the following.
[1] A step of copolymerizing a polymerizable monomer (A) selected from the group consisting of a compound represented by the formula (1) and a reactive derivative thereof with another polymerizable monomer (B) And a method of producing a liquid crystal polymer.

[Wherein, Ar ₁ and Ar ₂ may be the same or different, Ar ₁ is a benzene ring or a naphthalene ring, and Ar ₂ is selected from the group consisting of a benzene ring, a naphthalene ring and a biphenyl ring ]
[2] The liquid crystal according to [1], wherein the compound represented by the formula (1) is 4-hydroxybenzoic acid 4-hydroxyphenyl ester and / or 6-hydroxy-2-naphthoic acid 4-hydroxyphenyl ester Method of producing a polymer
[3] The liquid crystal polymer according to [1] or [2], wherein the polymerizable monomer (A) is 50 mol parts or less with respect to 100 mol parts of the total amount of other polymerizable monomers (B) Manufacturing method.
[4] Other polymerizable monomers (B) are aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines, aliphatic diols and fats The manufacturing method of the liquid crystal polymer in any one of [1]-[3] which is 1 or more types of compounds selected from the group which consists of group carboxylic acid.
[5] The method for producing a liquid crystal polymer according to any one of [1] to [4], wherein the other polymerizable monomer (B) contains an aromatic hydroxycarboxylic acid.
[6] The method for producing a liquid crystal polymer according to [4] or [5], wherein the aromatic hydroxycarboxylic acid is 4-hydroxybenzoic acid and / or 2-hydroxy-6-naphthoic acid.

Claims (4)

A liquid crystal comprising a step of copolymerizing a polymerizable monomer (A) selected from the group consisting of a compound represented by the formula (1) and a reactive derivative thereof with another polymerizable monomer (B) A method of producing a polymer ,
The total amount of the polymerizable monomers (A) is 10 to 50 parts by mole relative to 100 parts by mol of the total amount of other polymerizable monomers (B), and the other polymerizable monomers (B) The production method, wherein) is one or more selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid and aromatic diol .

[Wherein, Ar ₁ and Ar ₂ may be the same or different, Ar ₁ is a benzene ring or a naphthalene ring, and Ar ₂ is selected from the group consisting of a benzene ring, a naphthalene ring and a biphenyl ring ]   The liquid crystal polymer according to claim 1, wherein the compound represented by the formula (1) is 4-hydroxybenzoic acid 4-hydroxyphenyl ester and / or 6-hydroxy-2-naphthoic acid 4-hydroxyphenyl ester. Method. The manufacturing method of the liquid crystal polymer in any one of Claims 1-2 in which another polymerizable monomer (B) contains aromatic hydroxycarboxylic acid. The method for producing a liquid crystal polymer according to any one of claims 1 to 3, wherein the aromatic hydroxycarboxylic acid is 4-hydroxybenzoic acid and / or 2-hydroxy-6-naphthoic acid.