JP3988775B2 - Liquid crystal polymer - Google Patents

Description

The present invention relates to a method for producing a liquid crystal polyester .

Unlike polymers that do not exhibit liquid crystallinity, such as polypropylene and polyethylene, liquid crystal polymers represented by liquid crystal polyester and the like have rigid molecules, so that no entanglement occurs even in a molten state, and molecular chains are remarkably aligned in the flow direction. For this reason, even a slight change in shear shows a behavior in which the melt viscosity greatly fluctuates, or a behavior in which the melt viscosity suddenly decreases with an increase in temperature. Due to this unique behavior, it has been difficult to mold the liquid crystal polymer itself into a molded body such as a film.
In order to solve this problem, for example, a resin composition having improved molding processability by combining a liquid crystal polymer and a copolymer having a functional group reactive with the liquid crystal polymer has been proposed ( For example, see Patent Document 1 and Patent Document 2.)
However, when molded articles such as films are molded using these resin compositions, although there is excellent molding processability, there are cases in which fine irregularities such as fish eyes appear in or on the molded articles such as films. .
Due to the appearance problem due to such a small amount, the usage in use may be limited.

JP-A-9-12744 Japanese Patent Laid-Open No. 9-286903

An object of the present invention is to provide a method for producing a liquid crystal polyester used in a liquid crystal polymer resin composition that gives a molded article having an excellent appearance, with reduced amounts of fish eyes and other irregularities appearing inside and on the molded article. It is in.

The present inventors have made intensive studies to solve the above problems, a liquid crystal poly ester content is 500ppm or less by weight of pentamer following ingredients, by using as a raw material for liquid crystal polymer resin composition The present inventors have found that the amount of fish eyes and other irregularities appearing in and on the molded body can be significantly reduced, and the present invention has been completed.

That is, the present invention
[1] A liquid crystal polyester selected from the following (1) to (4), wherein the liquid crystal polyester is degassed and kneaded so that the content of the pentamer or less component on a weight basis is relative to the liquid crystal polyester . method for producing a liquid crystal polyester to be 500ppm or less.
[Liquid crystal polyester]
(1) Obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer, an aromatic diol monomer, and an aromatic hydroxycarboxylic acid monomer (2) Obtained by polymerizing a combination of different aromatic hydroxycarboxylic acid monomers (3) What is obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer and an aromatic diol monomer (4) It relates to what is obtained by reacting an aromatic hydroxycarboxylic acid monomer with polyethylene terephthalate,
[2] A pentamer or less extracted from a liquid crystal polymer under pressure using a solvent containing a heteroatom at a temperature lower than the critical temperature of the solvent and lower than the deflection temperature under load of the liquid crystal polymer. It is the value calculated by the total weight of the component of (1), It is related with the manufacturing method of the liquid crystalline polyester as described in [1].

The liquid crystal poly ester pentamer content of less weight of the components is 500ppm or less, by using as a raw material for liquid crystal polymer resin composition, it is possible to significantly reduce the amount of hard spots such as fish eyes.

The present invention will be described in detail below.
The liquid crystal polyester of the present invention is a liquid crystal polyester that exhibits liquid crystallinity when melted, called a thermotropic liquid crystal polymer. Specifically,
(1) those obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer with an aromatic diol monomer and an aromatic hydroxycarboxylic acid monomer (2) those obtained by polymerizing a combination of aromatic hydroxycarboxylic acid monomers of the heterologous (3) Obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer and an aromatic diol monomer (4) Examples obtained by reacting polyethylene terephthalate polyester with an aromatic hydroxycarboxylic acid monomer, etc. An anisotropic melt is formed at a temperature of 400 ° C. or lower. Instead of these aromatic dicarboxylic acid monomers, aromatic diol monomers, and aromatic hydroxycarboxylic acid monomers, those ester-forming derivative monomers can also be used. Further, instead of these aromatic dicarboxylic acid monomer, aromatic diol monomer and aromatic hydroxycarboxylic acid monomer, those in which the aromatic nucleus is substituted with a halogen atom, an alkyl group, an aryl group or the like can also be used.

(1 ′) The following repeating structural unit derived from an aromatic dicarboxylic acid monomer:

各構造における核中の水素原子はハロゲン原子、アルキル基、アリール基で置換されていてもよい。

The hydrogen atom in the nucleus in each structure may be substituted with a halogen atom, an alkyl group, or an aryl group.

(2 ′) The following repeating structural unit derived from an aromatic diol monomer:

各構造における核中の水素原子はハロゲン原子、アルキル基、アリール基で置換されていてもよい。

The hydrogen atom in the nucleus in each structure may be substituted with a halogen atom, an alkyl group, or an aryl group.

各構造における核中の水素原子はハロゲン原子、アルキル基、アリール基で置換されていてもよい。 (3 ′) The following repeating structural unit derived from an aromatic hydroxycarboxylic acid monomer:

The hydrogen atom in the nucleus in each structure may be substituted with a halogen atom, an alkyl group, or an aryl group.

なる上記モノマーに由来する繰り返し構造単位を含むものであり、さらに好ましくは該繰り返し構造単位を少なくとも全体の３０モル％以上含むものである。具体的にはモノマーに由来する繰り返し構造単位の組み合わせが下記（Ｉ）〜（VI）のいずれかのものが好ましい。下記の液晶ポリエステルには芳香族環にハロゲン基、アルキル基、アリール基が置換したものを用いることができる。 A particularly preferred liquid crystal polyester is a balance of heat resistance, mechanical properties and processability.

It contains a repeating structural unit derived from the above monomer, and more preferably contains at least 30 mol% of the repeating structural unit. Specifically, the combination of repeating structural units derived from monomers is preferably any of the following (I) to (VI). As the following liquid crystal polyester, those in which an aromatic ring is substituted with a halogen group, an alkyl group or an aryl group can be used.

  Regarding the production methods of the liquid crystalline polyesters (I) to (VI), for example, Japanese Patent Publication No. 47-47870, Japanese Patent Publication No. 63-3888, Japanese Patent Publication No. 63-3891, Japanese Patent Publication No. 56-18016, No. 2-51523 and the like. Among these, a combination of (I), (II) or (IV) is preferable, and a combination of (I) or (II) is more preferable.

  In the field where particularly high heat resistance is required, the liquid crystalline polyester has 30 to 80 mol% of repeating units (a ′) derived from the following monomers, and 0 to 10 repeating units (b ′) derived from the following monomers. A liquid crystal polyester comprising 10% to 25% by mole of a repeating unit (c ′) derived from the following monomer and 10% to 35% by mole of a repeating unit (d ′) derived from the following monomer is preferably used.

（式中、Ａｒは２価の芳香族基である。上記（ａ’）〜（ｄ’）の芳香族環にはハロゲン基、アルキル基、アリール基が置換したものを用いることができる。） 上記モノマーに由来する繰り返し構造単位（ｄ’）はジオールモノマー由来のものが好ましく、特に高い耐熱性が要求される用途には全芳香族のジオールモノマー由来のものが好ましい。上記液晶ポリエステルの中でも、環境問題等の見地から使用後の焼却等の廃棄の容易さを求められる分野には、ここまでに挙げたそれぞれに要求される分野の好ましい組み合わせの中で、特に炭素、水素、酸素のみからなる組み合わせによる液晶ポリエステルが好ましく用いられる。

(In the formula, Ar is a divalent aromatic group. The aromatic rings of the above (a ′) to (d ′) can be substituted with a halogen group, an alkyl group, or an aryl group.) The repeating structural unit (d ′) derived from the monomer is preferably derived from a diol monomer, and is preferably derived from a wholly aromatic diol monomer for applications requiring particularly high heat resistance. Among the above-mentioned liquid crystalline polyesters, in the field where the ease of disposal such as incineration after use is required from the viewpoint of environmental problems, among the preferred combinations of the fields required so far, especially carbon, A liquid crystal polyester composed of a combination of only hydrogen and oxygen is preferably used.

LCD poly esters of the present invention, inter alia liquid crystal polyester having a repeating structural unit derived from such monomers described above, the content of weight of 5 or less monomer component is of 500ppm or less with respect to the liquid crystal poly ester . By using the liquid crystal poly ester may reduce the amount of hard spots such as fish eyes in the shaped body such as a film. The content is more preferably 400 ppm or less, and still more preferably 300 ppm or less.

Method for determining the content of weight of 5 or less monomer components contained in the liquid crystal poly ester is not particularly limited as long as it is a method that can accurately calculate, for example, 5 weight liquid crystal poly ester with a solvent Examples include a method of extracting components below the body and quantifying the total weight of the components.
Here, the "5-mer or less" means that repeating structural unit derived from a monomer constituting the liquid crystal poly ester is 5 or less.

The solvent used for extraction is not particularly limited as long as the solvent can be sufficiently dissolve the pentamer following components contained in the liquid crystal poly esters include, for example, a solvent containing a hetero atom. The solvent containing a hetero atom means a solvent containing an atom other than carbon. Specifically, for example, ketones such as acetone and methyl isobutyl ketone, alcohols such as methanol, ethanol and 2-propanol, diethyl ether, Acyclic protons such as methyl butyl ether, cyclic ethers such as tetrahydrofuran and dioxane, halogenated hydrocarbons such as methylene chloride and chloroform, nitriles such as acetonitrile and benzonitrile, aprons such as N-methylpyrrolidone and dimethylformamide Polar solvents, ethyl acetate, pyridine ethyl acetate, and the like. Two or more solvents may be used.

The weight ratio of the solvent to the liquid crystal poly ester, a combination of a solvent used as the liquid crystal poly esters, and, although appropriately determined by the volume of the vessel used for the extraction, usually in the range of 50 times or more 5-fold.

When extracting pentamer following components contained in the liquid crystal poly ester from the liquid crystal poly ester, a solvent containing a hetero atom, is at a temperature lower than the deflection temperature under load of the low temperature and the liquid crystal poly ester than the critical temperature of the solvent It is preferable to extract under pressure under temperature conditions. While the extraction temperature is appropriately determined depending on the load cottonseed temperature of the critical temperature and the liquid crystal poly ester solvent, extraction temperature temperature preferably cooler than the deflection temperature under load of the low temperature and the liquid crystal poly ester than the critical temperature of said solvent, lower than the boiling point at atmospheric pressure of the solvent used for the extraction, more preferably it is a temperature range which is cooler than the heat deflection temperature of the low temperature and the liquid crystal poly ester than the critical temperature of the solvent. When the temperature of the solvent is above the critical temperature, there is a case where the liquid crystal poly ester is decomposed undesirably. Further, at a temperature of more than the deflection temperature under load, on the 5 or less monomer components contained in the liquid crystal poly ester might decomposition product of the liquid crystal poly ester is mixed, the liquid crystal poly esters of the extractor deforms This is not preferable because the piping may be blocked. Moreover, in order to increase the yield of the component below a pentamer, it is also preferable to repeat the above extraction twice or more.

  About the pressure conditions of extraction, in order to improve the permeability | transmittance of the solvent to a liquid crystal polymer, it is preferable to carry out under pressure and it is preferable that it is 3 Mpa or more. If the pressure is too high, the cost of the container is increased, so 20 MPa or less is preferable. A range of 5 MPa or more and 15 MPa or less is more preferable.

Time of extraction, types of liquid crystal poly ester, temperature, pressure, depending on the conditions such as the type of solvent, it is be determined the time sufficient pentamer following components from the liquid crystal poly esters are extracted as appropriate, Usually, it is in the range of 5 minutes to 120 minutes.

In the present invention, the total weight of pentamer following components in the liquid crystal poly ester can be obtained by quantitation of the components.
Quantitative methods Although not particularly limited, for example, after extraction to the liquid crystal poly esters by solvent, and a method for quantifying the pentamer following component obtained by extraction by a chromatographic method Can be mentioned. Examples of chromatographic methods include liquid chromatographic methods, size exclusion chromatographic methods, supercritical fluid chromatographic methods, gas chromatographic methods, thin layer chromatographic methods, and the like. From the viewpoint of easy analysis and good separation, liquid chromatography, size exclusion chromatography, and gas chromatography are preferred.

When quantifying by the above chromatographic method, for example, an absolute calibration curve method for obtaining the content from the ratio of the detected peak area of a standard sample of a pentamer or less component to the actually measured detection peak area of a pentamer or less component In addition, by adding a standard substance different from the pentamer or lower component and using a method such as an internal standard method for obtaining the content from the ratio of the detection peak areas of both, it is contained in the liquid crystal polymer. The total weight of the components below the pentamer can be determined. In this way, the liquid crystal poly ester before extraction to the content of the weight of 5 or less monomer component contained in the liquid crystal poly ester can confirm whether it is 500ppm or less.

The production method of the present invention is devolatilization and kneading of a liquid crystal polyester having a weight-based content of a component of pentamer or less of 500 ppm or less, specifically, at a sufficient temperature in a single-screw or twin-screw extruder. Examples thereof include a method of performing devolatilization kneading, and a method of performing devolatilization kneading at a temperature sufficient for kneading using a twin screw extruder at 0.05 MPa or less.

LCD poly ester 5 mer or less by weight based on the weight of the component content of is 500ppm or less of the present invention obtained by the above method, the liquid crystal poly ester, by using as a raw material for liquid crystal polymer resin composition, molded The amount of fish eyes and other irregularities appearing in the body and on the surface can be significantly reduced.
Although the details about the reduction mechanism of such granular structure is not known, by reducing the content of 5 or less monomer components of the liquid crystal poly ester 500ppm or less, and 5 or less monomer components of the liquid crystal poly ester presumably because some interaction between the copolymer having a functional group reactive with liquid crystal poly ester (B) is reduced.

Then using the such liquid poly esters of the present invention, which is another component used in preparing the liquid crystalline polymer resin composition which gives a molded article having excellent appearance the amount of lumps is reduced (B) for a description To do.
When molding a liquid crystal poly esters of the present invention, moldability from the viewpoint of the performance of the molded article obtained, a liquid crystal poly ester following 500ppm is (A) 5 or less monomer component content, (B) the A liquid crystal polymer resin composition comprising a copolymer having a functional group reactive with a liquid crystal polymer is usually used.

Component used in the liquid crystal polymer resin composition (B) is a copolymer having a functional group having reactivity to the liquid crystal poly esters. Examples of the functional group having reactivity with such liquid crystal poly ester is not particularly limited if it has a reactivity with the liquid crystal polyester, specifically, an oxazolyl group, an epoxy group, an amino group, and the like. Preferably, it is an epoxy group.
Epoxy groups and the like may exist as part of other functional groups, and examples of such groups include glycidyl groups.

In copolymer (B), is not particularly restricted but a method for introducing a functional group having a reactivity with the liquid crystal poly ester in the copolymer can be conducted by a known method. For example, at the copolymer synthesis stage, it is possible to introduce a monomer having the functional group by copolymerization, or to graft copolymerize the monomer having the functional group to the copolymer. It is.

  The copolymer (B) in the present invention may be a thermoplastic resin or rubber, or a mixture or reaction product of a thermoplastic resin and rubber. A rubber can be selected when importance is attached to the thermal stability and flexibility of a molded article such as a film or a sheet obtained by using the liquid crystal polymer resin composition.

First, the case where the copolymer (B) is rubber will be described.
As the rubber having an epoxy group as a specific example of a copolymer having a functional group reactive with liquid crystal poly ester, (meth) acrylic acid ester - ethylene - (unsaturated glycidyl carboxylate and / or unsaturated glycidyl And ether) copolymer rubber.

  Here, (meth) acrylic acid ester means an ester obtained from acrylic acid or methacrylic acid and alcohols. Examples of alcohols include hydroxyl group-containing compounds having 1 to 8 carbon atoms. Specific examples of (meth) acrylic acid esters include methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and the like. Can do. In addition, as (meth) acrylic acid ester, the 1 type may be used independently or 2 or more types may be used together.

The rubber or as a copolymer having a functional group reactive with liquid crystal poly esters, other than rubber in the thermoplastic resin, unsaturated carboxylic acid glycidyl ester in functional group reactive with liquid crystal poly ester and unsaturated As a monomer constituting the saturated glycidyl ether, for example, the following general formula

（式中、Ｒは、エチレン系不飽和結合を有する炭素数２〜１３の炭化水素基を表し、Ｘは、−Ｃ(Ｏ)Ｏ−、−ＣＨ₂−Ｏ−または

を表す。）で示される単量体を用いることができる。

(In the formula, R represents a hydrocarbon group having 2 to 13 carbon atoms having an ethylenically unsaturated bond, and X represents —C (O) O—, —CH ₂ —O— or

Represents. ) Can be used.

  More specifically, examples of the unsaturated carboxylic acid glycidyl ester include glycidyl acrylate, glycidyl methacrylate, itaconic acid diglycidyl ester, butenetricarboxylic acid triglycidyl ester, and p-styrene carboxylic acid glycidyl ester.

  Examples of the unsaturated glycidyl ether include vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, methacryl glycidyl ether, and styrene-p-glycidyl ether.

  Among the above copolymer rubbers in the present invention, those having a content of (meth) acrylate monomer units in the copolymer of 40 to 97% by weight are preferred. If it is outside this range, the thermal stability and mechanical properties of the resulting molded product such as a film or sheet tend to be insufficient. It is still more preferable if it is in the range of 45 to 70% by weight.

The content of ethylene monomer units is preferably in the range of 3 to 50% by weight, more preferably in the range of 10 to 49% by weight. The content of the unsaturated carboxylic acid glycidyl ether monomer unit and / or the unsaturated glycidyl ether monomer unit is preferably in the range of 0.1 to 30% by weight.
If it is outside this range, the thermal stability and mechanical properties of the resulting molded product such as a film or sheet tend to be insufficient. A range of 0.5 to 20% by weight is still more preferable.

The copolymer rubber can be produced by a usual method, for example, bulk polymerization using a free radical initiator, emulsion polymerization, solution polymerization or the like. A typical polymerization method is a method described in Japanese Patent Publication No. 48-11388, Japanese Patent Application Laid-Open No. 61-127709, etc., and in the presence of a polymerization initiator that generates free radicals, a pressure of 500 kg / cm. ² (49.0 MPa) or more, and can be produced under conditions of a temperature of 40 to 300 ° C.

  Examples of the rubber that is a copolymer of the component (B) of the liquid crystal polymer resin composition include acrylic rubber having a functional group reactive with liquid crystal polyester in addition to the above rubber, and a functional group having reactivity with liquid crystal polyester. It is also possible to use a vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber having:

The acrylic rubber here is synthesized from a monomer, and specific examples of such a monomer include general formulas (1) to (3).
_{CH 2 = CH-C (O} ) -OR 1 (1)
_{CH 2 = CH-C (O} ) -OR 2 OR 3 (2)
^{_{CH 2 = CR 4 -C (O}} ) -O (R 5 (C (O) O) nR 6 (3)
(Wherein R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cyanoalkyl group, R ² represents an alkylene group having 1 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 12 carbon atoms. R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 30 carbon atoms, R ⁶ represents an alkyl group having 1 to 20 carbon atoms or a derivative thereof, and n represents an integer of 1 to 20. .) And the like.

The component ratio of the acryl rubber having a functional group reactive with liquid crystal poly ester, at least one monomer selected from a monomer represented by the above general formula (1) to (3) 40 0.09 to 99.9% by weight, unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether 0.1 to 30.0% by weight, and represented by the above general formulas (1) to (3) Typically, the unsaturated monomer copolymerizable with the monomer is 0.0 to 30.0% by weight. When the component ratio of the acrylic rubber is within the above range, the composition tends to have good heat resistance, impact resistance, and moldability.

  Specific examples of the alkyl acrylate ester represented by the general formula (1) include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, Examples include decyl acrylate, dodecyl acrylate, and cyanoethyl acrylate. One or more of these can be used as the main component of the acrylic rubber.

  Examples of the acrylic acid alkoxyalkyl ester represented by the general formula (2) include methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, and ethoxypropyl acrylate. One or more of these can be used as the main component of the acrylic rubber.

  Examples of the acrylic acid derivative represented by the general formula (3) include acryloyloxy-butyric acid methyl ester and methacryloyloxyheptanoic acid methyl ester. One or more of these can be used as the main component of the acrylic rubber.

As a constituent component of the acrylic rubber, an unsaturated monomer copolymerizable with the monomers represented by the general formulas (1) to (3) can be used as necessary.
Examples of such unsaturated monomers include styrene, α-methylstyrene, acrylonitrile, halogenated styrene, methacrylonitrile, acrylamide, methacrylamide, vinylnaphthalene, N-methylolacrylamide, vinyl acetate, vinyl chloride, chloride. Examples include vinylidene, benzyl acrylate, methacrylic acid, itaconic acid, fumaric acid, maleic acid and the like.

  The method for producing the acrylic rubber is not particularly limited, and is described, for example, in JP 59-1113010, JP 62-64809, JP 3-160008, or WO 95/04764. Such a known polymerization method can be used, and it can be produced by emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization in the presence of a radical initiator.

  In addition to the acrylic rubber, examples of the vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber having a functional group reactive with the liquid crystal polymer include (a) a vinyl aromatic hydrocarbon compound as a main component. Examples thereof include a rubber obtained by epoxidizing a block copolymer composed mainly of a sequence and (b) a conjugated diene compound, and a rubber obtained by epoxidizing a hydrogenated product of the block copolymer.

Examples of the vinyl aromatic hydrocarbon compound (a) include styrene, vinyl toluene, divinyl benzene, α-methyl styrene, p-methyl styrene, vinyl naphthalene, and styrene is particularly preferable.
Examples of the conjugated diene compound (b) include butadiene, isoprene, 1,3-pentadiene, 3-butyl-1,3-octadiene, and the like, and butadiene or isoprene is preferable.

  Such vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer or hydrogenated product thereof can be produced by a known method, for example, Japanese Patent Publication No. 40-23798 and Japanese Patent Publication No. 59-133203. The method is described.

The rubber used as the copolymer of the component (B) of the liquid crystal polymer resin composition can be vulcanized as necessary and used as a vulcanized rubber.
Vulcanization of the above (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber is a polyfunctional organic acid, polyfunctional amine compound, imidazole compound, etc. However, the present invention is not limited to these.

Next, the case where the copolymer (B) of the component (B) of the liquid crystal polymer resin composition is a thermoplastic resin other than rubber will be described. When the copolymer (B) is a thermoplastic resin other than rubber, for example,
(A) Ethylene (b) Unsaturated carboxylic acid glycidyl ester monomer and / or unsaturated glycidyl ether monomer (c) Ethylene unsaturated ester compound The above (a) and (b) or (a) and (b) An epoxy group-containing ethylene copolymer obtained by reacting with (c) can be exemplified. Among them, the ethylene unit in the copolymer is 50 to 99% by weight, the unsaturated carboxylic acid glycidyl ester monomer unit and / or the unsaturated glycidyl ether monomer unit is 0.1 to 30% by weight, and the ethylenically unsaturated ester compound unit is It is preferable to be in the range of 0 to 50% by weight. Further, among these, the range of the unsaturated carboxylic acid glycidyl ester monomer unit and / or the unsaturated glycidyl ether monomer unit is more preferably 0.5 to 20% by weight.

  Specific examples of the ethylenically unsaturated ester compound (c) include, for example, vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Carboxylic acid vinyl ester, α, β-unsaturated carboxylic acid alkyl ester, and the like can be mentioned, among which vinyl acetate, methyl acrylate, and ethyl acrylate are preferable.

  Specific examples of the epoxy group-containing ethylene copolymer include, for example, a copolymer composed of ethylene units and glycidyl methacrylate units, a copolymer composed of ethylene units, glycidyl methacrylate units and methyl acrylate units, ethylene units and glycidyl methacrylate units. And a copolymer composed of ethyl acrylate units, a copolymer composed of ethylene units, glycidyl methacrylate units and vinyl acetate units.

  The melt mass flow rate (hereinafter sometimes referred to as MFR. JIS K7210, 190 ° C., 2.16 kg load) of the epoxy group-containing ethylene copolymer is preferably 0.5 to 100 g / 10 minutes, more preferably 2 to 2. 50 g / 10 min. The melt mass flow rate may be outside this range, but if the melt mass flow rate exceeds 100 g / 10 min, it is not preferable in terms of mechanical properties when the composition is formed, and if it is less than 0.5 g / 10 min, the component ( The compatibility with the liquid crystal polymer represented by A) liquid crystal polyester is inferior, which is not preferable.

As for the epoxy group-containing ethylene copolymer, one having a flexural modulus of 10 to 1300 kg / cm ² (0.98 to 127.49 MPa) can be selected, but 20 to 1100 kg / cm ² ( Those of 1.96 to 107.87 MPa) are more preferable.
If the flexural modulus is outside this range, the moldability and mechanical properties of the composition tend to be insufficient.

  The epoxy group-containing ethylene copolymer is usually an unsaturated epoxy compound and ethylene in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. It is produced by a high pressure radical polymerization method for copolymerization. It can also be produced by a method in which an unsaturated epoxy compound and a radical generator are mixed with polyethylene and melt graft copolymerized in an extruder.

The copolymer of the component (B) of the liquid crystal polymer resin composition contains 0.1 to 30% by weight of an unsaturated carboxylic acid glycidyl ester monomer unit and / or an unsaturated glycidyl ether monomer unit in the copolymer. Is preferably used. When the weight% of said monomer units contained in the copolymer is less than 0.1 wt%, low interaction with the crystal poly ester, or film formability deteriorates as a result not easily finely dispersed, obtained The performance of the obtained film tends to deteriorate. On the other hand, when the content is more than 30% by weight, the reactivity becomes high and self-crosslinking tends to occur, and the resulting film tends to deteriorate in appearance.

As the copolymer of component (B) of the liquid crystal polymer resin composition, it is preferable to use a copolymer having a heat of fusion of crystals of less than 3 J / g.
If the heat of fusion of the crystal is 3 J / g or more, there is a tendency that unevenness or the like is generated on the film due to poor melting.

The copolymer of component (B) of the liquid crystal polymer resin composition preferably has a Mooney viscosity of 3 to 70, more preferably 3 to 30, and particularly preferably 4 to 25.
The Mooney viscosity here refers to a value measured using a 100 ° C. large rotor according to JIS K6300. If it is outside these ranges, the thermal stability of the composition tends to be lowered.

  In addition, the copolymer of the component (B) of the liquid crystal polymer resin composition is one of the preferred combinations listed so far in fields where ease of disposal such as incineration after use is required from the viewpoint of environmental problems. In particular, a copolymer comprising a combination of only carbon, hydrogen, and oxygen is preferably used.

One embodiment of a liquid crystal polymer resin composition of the present invention, (A) a liquid crystal poly ester 56.0 to 99.9 wt%, preferably 70.0 to 99.9 wt%, more preferably 80 to 98 weight %, And (B) a copolymer having a functional group reactive with the liquid crystal polymer is 44.0 to 0.1% by weight, preferably 30.0 to 0.1% by weight, more preferably 20 to 2% by weight. % Containing resin composition.
When the component (A) is less than 56.0% by weight, the water vapor barrier property and heat resistance of the film obtained from the composition tend to be lowered. On the other hand, when the component (A) exceeds 99.9% by weight, the moldability of the composition tends to be lowered, and the cost becomes expensive.

Liquid crystal polymer resin composition and its molded article of the present invention comprises a copolymer having a functional group (B) dispersed phase reactive with the liquid crystal polymer and a liquid crystal poly ester (A) as described above and the continuous phase It is preferable to consist of a liquid crystal polymer resin composition.
Liquid crystal when the poly ester (A) is not a continuous phase, tends to heat resistance of the resulting composition and molded article to become bad.

In the liquid crystal polymer resin composition and the molded product thereof, the average dispersed particle size of the dispersed phase of the component (B) is preferably 3 μm or less, and more preferably 2 μm or less.
If the average dispersed particle size of the component (B) exceeds 3 μm, the appearance of the molded product may be impaired or the physical properties may be deteriorated.
The average dispersed particle size can be obtained, for example, by cutting a liquid crystal polymer resin composition or a molded product and observing the central portion of the cross section with an electron microscope.

In the copolymer and the resin composition of the liquid crystal poly ester having such a functional group, although details of the mechanism there is not known, the reaction between the components of the composition (A) and component (B) It is considered that the component (A) forms a continuous phase and the component (B) is finely dispersed, thereby improving the mechanical properties of the resulting composition.

As a method for manufacturing a liquid crystal polymer resin composition comprising a liquid crystal poly ester and the copolymer in the present invention may be a known method. For example, a method of mixing each component in a solution state and evaporating the solvent or precipitating in the solvent can be mentioned. Specifically, a method of kneading each component in a molten state can be selected. For melt kneading, generally used kneading apparatuses such as a single or twin screw extruder and various kneaders can be used. A biaxial high kneader is particularly preferable.
In the melt-kneading, the cylinder setting temperature of the kneading apparatus can be selected from a range of 200 to 360 ° C, and further can be carried out in a range of 230 to 350 ° C.

  At the time of kneading, each component may be mixed uniformly in advance with a device such as a tumbler or a Henschel mixer, or if necessary, a method of omitting the mixing and separately supplying each of the components separately to the kneading device is also used. be able to.

In the liquid crystal polymer resin composition in the present invention, an organic filler, an antioxidant, a heat stabilizer, a light stabilizer, a flame retardant, a lubricant, an antistatic agent, a rust preventive agent, a crosslinking agent, and a foaming agent are included as necessary. Various additives such as fluorescent agents, surface smoothing agents, surface gloss improvers, mold release improvers such as fluororesins can be added during the manufacturing process or in subsequent processing steps. It is preferable to use one that does not leave ash later.

  There are no particular limitations on the method for producing a molded article such as a film comprising such a liquid crystal polymer resin composition. For example, a T-die method in which a molten resin is extruded and wound from a T-die, and an extruder provided with an annular die Extrusion of the molten resin into a cylindrical shape, cooling method for winding up, injection molding method, extrusion molding method, melt spinning molding method, heat press method, or molding method such as calendar molding method or roll molding method, The T die method and the inflation molding method are preferable. A molded body can be obtained by molding the liquid crystal polymer resin composition by the molding method described above.

  Although the setting conditions of the extruder at the time of production of a molded article such as a film can be appropriately set according to the composition of the composition, a range of 200 to 360 ° C. can be selected as the cylinder setting temperature, and 230 to 350 ° C. It is suitable if it is in the range. If the content is outside this range, the composition tends to be thermally decomposed or difficult to mold.

As a specific example of the method for producing a molded body, for example, when a film is formed by the T-die method, the slit interval of the T-die is usually 0.2 to 2.0 mm, and among them, 0.2 to 1.2 mm. The interval of is preferable.
When manufacturing a film by uniaxial stretching, the draft ratio of a film can be made into the range of 1.1-40. Preferably it is 10-40, More preferably, it is the range of 15-35.

  The draft ratio here refers to a value obtained by dividing the cross-sectional area of the T-die slit by the film cross-sectional area of the plane perpendicular to the longitudinal direction. When the draft ratio is less than 1.1, the film strength is insufficient, and when the draft ratio exceeds 45, the surface smoothness of the film tends to be insufficient. The draft ratio can be set by controlling the setting conditions of the extruder, the winding speed, and the like.

  In the biaxially stretched film, the composition is melt-extruded under the same setting conditions of the extruder as in the film formation of the uniaxially stretched film, and the melt sheet extruded from the T-die is longitudinally and perpendicular to the longitudinal direction (lateral direction). ) Or a melt sheet extruded from a T-die is first stretched in the longitudinal direction, and then this stretched sheet is stretched in the transverse direction from the tenter at a high temperature of 100 to 300 ° C. in the same process. It is obtained by the method.

  When manufacturing a biaxially stretched film, the stretch ratio can be 1.2 to 20 times in the longitudinal direction and 1.2 to 20 times in the transverse direction. When the stretch ratio is out of the above range, the composition film tends to have insufficient strength or it becomes difficult to obtain a film having a uniform thickness.

  When producing a film by the inflation method, the liquid crystal polymer resin composition is first supplied to a melt-kneading extruder equipped with a die having an annular slit. The cylinder set temperature is 200 to 360 ° C., preferably 230 to 350 ° C., and after melt-kneading, the cylindrical film is extruded through the annular slit of the extruder. The interval between the annular slits is usually 0.1 to 5 mm, preferably 0.2 to 2 mm. The diameter of the annular slit is usually 20 to 1000 mm, preferably 25 to 600 mm.

  A draft in the longitudinal direction (MD) is applied to the melt-extruded molten resin film, and a transverse direction (TD) perpendicular to the longitudinal direction by blowing air or an inert gas such as nitrogen gas from the inside of the tubular film. The film can be expanded and stretched.

In inflation molding, the blow ratio can be 1.5 to 10, and the preferred draft ratio is 1.5 to 40.
If the setting conditions at the time of inflation molding are out of the above range, it tends to be difficult to obtain a high-strength film having a uniform thickness and no wrinkles.

  Usually, the expanded film is air-cooled or water-cooled around the circumference, and then taken through a nip roll.

  In the inflation molding, conditions can be selected such that the cylindrical melt film expands to a smooth surface with a uniform thickness according to the composition of the liquid crystal polymer resin composition.

  The method for producing the hollow molded body comprising the liquid crystal polymer resin composition is not particularly limited, and can be produced by the same method as described above, but the blow molding method is preferably used among them. . Examples of the shape of the obtained hollow molded body include hollow containers such as bottles and gasoline tanks, pipes, and the like.

  By the above method, the molded object containing the liquid crystal polymer resin composition containing the liquid crystal polymer whose content of a pentamer or less component is 500 ppm or less with respect to a liquid crystal polymer can be manufactured.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this does not limit the scope of the present invention. Each physical property was measured by the following method.

[Measurement method of physical properties]
Optical anisotropy: The optical anisotropy in the molten state of the sample resin is that the sample resin powder having a particle size of 250 μm or less placed on the heating stage is heated at 25 ° C./min under polarized light and observed with the naked eye or transmitted. This was done by recording the amount of light on an XY recorder.

Analysis of content of components below pentamer: About 2 g of sample resin was filled into a SUS container having a volume of 11 ml, and a pressure of 6.9 MPa was used using a high-speed solvent extraction device (Dionex, ASE-200 type). 2-Propanol propanol was introduced so that the temperature would be 140 ° C., held for 10 minutes, and the components below the pentamer were extracted. Thereafter, the inside of the container is temporarily returned to atmospheric pressure, and 2-propanol is introduced again and held for 10 minutes under the above-described conditions, and then contains a pentamer or less component discharged from the SUS container by nitrogen purge. -The propanol solution (about 30 ml in total) was combined with the previous extraction solution, concentrated under reduced pressure, made up to 5 ml with tetrahydrofuran, and separated and analyzed under the following analytical conditions.
Analysis conditions: L-column ODS column (inner diameter: 4.6 mm, length: 15 cm, packing material particle size: 5 μm) manufactured by Chemical Substances Evaluation and Research Institute is attached to Agilent Liquid Chromatography Model 1100, and the components are pentamer or less. 10 μl of an analysis sample solution containing is added to separate components below the pentamer under gradient elution conditions described later at a column temperature of 40 ° C. and a flow rate of 1.0 ml / min, and ultraviolet detection connected to the chromatograph apparatus. The sum of the areas of the components detected when the detection wavelength of the detector was set to 254 nm was determined. Concerning the component content of pentamer or less, a first-order calibration curve is created using p-hydroxybenzoic acid, which is the main component of the monomer components that are the raw materials of the resin, and p-hydroxy is used using this calibration curve. It calculated | required as a benzoic acid conversion value.
The gradient elution conditions were as follows: the mobile phase was an aqueous solution of 0.1% acetic acid and an acetonitrile solution of 0.1% acetic acid, and after the start of the gradient, 0 minutes, 10 minutes, 20 minutes, 35 minutes, and 40 minutes. , 0.1% acetonitrile solution ratio was set to 10%, 10%, 30%, 100% and 100%, respectively.

Flow temperature: An index representing melt fluidity, measured by a capillary rheometer (manufactured by Shimadzu Corporation, Koka type flow tester CFT500 type) and heated at a heating rate of 4 ° C./min. When the molten sample resin (about 2 g) was extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm under a load of 100 kg / cm ² , the melt viscosity was expressed as a temperature (° C.) at which the melt viscosity showed 48000 poise.
Deflection temperature under load: Using a test piece having a length of 127 mm, a width of 12.7 mm, and a thickness of 6.4 mm, in accordance with ASTM D648, this test piece is placed on two fulcrums, and 18.6 kg / It means the temperature (° C.) when the load part is deformed 1/100 inch when a load of cm 2 is applied and the ambient temperature is raised at a constant rate.

  Average dispersed particle diameter of component (B): 100 mm × 6 mm × 10 mm test piece was injection molded with an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd., PS40E5ASE), and a 6 mm × 10 mm rectangular cross section of the resulting molded product After polishing the central part of the film, etching using chloroform, silver deposition was performed to obtain a sample, which was observed with SEM (S-2300 Hitachi Scanning Electron Microscope), and 50 particles randomly selected from the field of view. The diameter was averaged.

Reference Example 1 (liquid crystal poly ester component (A))
8.3 kg (60 mol) of p-acetoxybenzoic acid, 2.49 kg (15 mol) of terephthalic acid, 0.83 kg (5 mol) of isophthalic acid and 5.45 kg (20.2 mol) of 4,4′-diacetoxydiphenyl Was placed in a polymerization tank having a comb-shaped stirring blade, heated while stirring in a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour. Furthermore, it was polymerized for 1 hour under a reduced pressure of 60 mmHg. During this time, acetic acid gas produced as a by-product was liquefied and recovered and removed in a cooling tube, and polymerized with strong stirring, and the polymer was taken out from the system in a molten state. An aromatic liquid crystalline polyester having a flow rate of 333 ° C. and the following repeating structural units and a blending ratio was obtained.
Hereinafter, the liquid crystal polyester is abbreviated as A-1. This liquid crystal polymer exhibited optical anisotropy at 340 ° C. or higher under pressure. The ratio of the total weight of the components of pentamer or less contained in A-1 was 800 ppm with respect to the weight of A-1.

Reference Example 2 (Oligomer of liquid poly ester component (A))
In the same manner as in Reference Example 1, polymerization was carried out at 300 ° C. for 5 minutes to obtain an oligomer. While acetic acid gas produced as a by-product in the meantime was liquefied and recovered and removed by a cooling tube, polymerization was performed under strong stirring, and the polymer was taken out from the system in a molten state. The obtained oligomer was pulverized with a hammer mill manufactured by Hosokawa Micron Co., Ltd. to obtain particles of 2.5 mm or less. The obtained oligomer was less than octamer.

Reference Example 3 (component (B))
According to the method described in Example 5 of JP-A-61-127709, methyl acrylate / ethylene / glycidyl methacrylate = 59.0 / 38.7 / 2.3 (weight ratio), Mooney viscosity = 15 Got rubber. Hereinafter, the rubber may be abbreviated as B-1.
Here, the Mooney viscosity is a value measured using a large rotor at 100 ° C. according to JIS K6300.

Example 1
A-1 was devolatilized and melted under a reduced pressure of 0.04 MPa at a cylinder setting temperature of 350 ° C. and a screw rotation speed of 200 rpm using a TEX-30 type twin screw extruder manufactured by Nippon Steel Co., Ltd., which was provided with a pressure reducing part in the cylinder. Kneading was performed to obtain pellets. The pellets exhibited optical anisotropy at 340 ° C. or higher under pressure. The pellet flow temperature was 330 ° C. Hereinafter, the pellet may be abbreviated as A-2. The ratio of the total weight of the components of pentamer or less contained in A-2 was 200 ppm with respect to the weight of A-2. The average dispersed particle size of B-1 in the composition was 0.9 μm.
80% by weight of A-2 and 20% by weight of B-1 were melt kneaded using a TEX-30 type twin screw extruder manufactured by Nippon Steel Co., Ltd. at a cylinder set temperature of 350 ° C. and a screw rotation speed of 200 rpm. Pellets were obtained. The composition pellets exhibited optical anisotropy at 340 ° C. or higher under pressure. The flow temperature of the composition pellets was 328 ° C.
Pellets of this composition were supplied to a single-screw extruder of 60 mmφ equipped with a cylindrical die, melt kneaded at a cylinder setting temperature of 350 ° C. and a rotation speed of 60 rpm, a diameter of 70 mm, a lip interval of 1.0 mm, and a die setting temperature of 355 ° C. The molten resin is extruded upward from the cylindrical die, and then the dry air is pressed into the hollow portion of the tubular film to expand the tubular film. A liquid crystal polymer resin composition film of about 25 μm was obtained. The draw ratio in the take-up direction (take-off speed / discharge speed) was 17.7, and the blow ratio (the diameter of the expanded tubular film / die lip outer diameter) was 2.3. Hereinafter, the film may be abbreviated as f-1. The film appearance of f-1 had very few bumps. In the 200 mm square of f-1, the amount of irregularities in the film that can be visually confirmed was 4.

Comparative Example 1
80% by weight of A-1 and 20% by weight of B-1 were melt kneaded at normal pressure using the same apparatus as in Example 1 to obtain composition pellets. The composition pellets exhibited optical anisotropy at 340 ° C. or higher under pressure. The flow temperature of the composition pellets was 328 ° C. The average dispersed particle size of B-1 in the composition was 1.1 μm.
A liquid crystal polymer resin composition film was obtained from the pellets of this composition using the same apparatus as in Example 1. Hereinafter, the film may be abbreviated as f-2. The film appearance of f-2 had many bumps. In the 200 mm square of f-2, the amount of protrusions in the film that can be visually confirmed was 30 pieces.

Comparative Example 2
0.1 part by weight of the oligomer of Reference Example 2 was added to A-1, the total content of the pentamer and lower components in A-1 was 1800 ppm, and the apparatus similar to Example 1 was used at normal pressure. Melt kneading was performed to obtain a pellet of the composition. The average dispersed particle size of B-1 in the composition was 4.2 μm. A liquid crystal polymer resin composition film was obtained from the pellets of this composition using the same apparatus as in Example 1. The composition was slightly foamed during film forming, and the moldability was not sufficient. Hereinafter, the film may be abbreviated as f-3. The film appearance of f-3 was a lot. In the 200 mm square of f-3, the amount of protrusions in the film that can be visually confirmed was 60 pieces.

Claims (2)

A method for producing a liquid crystal polyester , wherein the liquid crystal polyester selected from the following (1) to (4) is degassed and kneaded so that the content of a pentamer or less component on a weight basis is 500 ppm or less with respect to the liquid crystal polyester.
[Liquid crystal polyester]
(1) Obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer, an aromatic diol monomer, and an aromatic hydroxycarboxylic acid monomer (2) Obtained by polymerizing a combination of different aromatic hydroxycarboxylic acid monomers (3) Obtained by polymerizing a combination of an aromatic dicarboxylic acid monomer and an aromatic diol monomer (4) Obtained by reacting an aromatic hydroxycarboxylic acid monomer with polyethylene terephthalate Using a solvent containing a hetero atom, the content of the pentamer or lower component extracted from the liquid crystal polymer under pressure under a temperature condition that is lower than the critical temperature of the solvent and lower than the deflection temperature under load of the liquid crystal polyester. The method for producing a liquid crystal polyester according to claim 1, wherein the liquid crystal polyester is a value calculated from a total weight.