JPH044253A - Colored thermotropic liquid crystal polymer composition - Google Patents

Abstract

PURPOSE:To obtain a colored thermotropic liquid crystal polymer composition having excellent heat-resistance, mechanical strength and moldability by compounding a burnt inorganic pigment to a thermotropic liquid crystal polymer consisting of a wholly aromatic polyester having high melting point, CONSTITUTION:The objective colored thermotropic liquid crystal polymer composition can be produced by compounding (A) a wholly aromatic polyester (co)polymer containing at least the monomer unit of formula and consisting of a thermotropic liquid crystal polymer having a melting point of >=300 deg.C, preferably a copolymer composed mainly of 4-hydroxybenzoic acid, biphenol and phthalic acid with (B) 0.2-60wt.% of a burnt inorganic pigment preferably exhibiting the weight decrease of <=0.05wt.% based on the objective composition after heating at 400 deg.C, e.g. a pigment composed mainly of a cobalt blue multiple oxides, titan yellow multiple oxides, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a colored thermotropic liquid crystal polymer composition having excellent heat resistance and moldability.

[Prior art] Thermotropic liquid crystal polymers have excellent heat resistance, moldability, and dimensional stability, and their development as materials is progressing rapidly. The demand for colored materials is increasing.

Examples of coloring thermotropic liquid crystal polymers include carbon black and titanium white.

JP-A-59-36154 discloses oven tableware using an aromatic polyester resin composition filled with talc and titanium white. Also, Tokkai Sho [i3
Japanese Patent No. 254159 discloses an aromatic polyester molding composition containing a specific carbon black.

However, as a coloring composition of an ultra-heat-resistant thermotropic liquid crystal polymer having a melting point of 300° C. or more, no composition that is satisfactory in terms of strength and heat resistance has been obtained. This is because the kneading and molding processes for coloring must be carried out at high temperatures near the melting point, and during these processes the resin and pigment are thermally degraded, resulting in a decrease in physical properties. For example, organic pigments are completely unusable, and even ordinary inorganic pigments are the same.

[Problem to be Solved by the Invention D1] The present invention solves the problem that thermotropic liquid crystal polymer coloring compositions with a melting point of 300° C. or higher are not satisfactory in terms of strength and heat resistance. be.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and have developed a thermoplastic resin which is a wholly aromatic polyester polymer or copolymer with a melting point of 300°C or higher. We have now invented a colored resin composition characterized by blending 0.2 to 60% by weight of an inorganic fired pigment into a tropic liquid crystal polymer.

Further details will be explained below.

The thermotropic liquid crystal polymer as used in the present invention is a thermoplastic meltable polymer that exhibits optical anisotropy when melted. Such a polymer exhibiting optical anisotropy when melted has a property in which the molecular chains of the polymer are regularly arranged in parallel in the melted state. The properties of the optically anisotropic melt phase are
This can be confirmed by the usual polarization test method using orthogonal polarizers.

Thermotropic liquid crystal polymers are made from polymers that are generally elongated, flat, and have multiple chains of extended bonds that are rigid and either coaxial or parallel along the long chains of the molecules. be done.

As stated above, the polymer that forms the optically anisotropic melt phase is a fully aromatic polyester polymer or copolymer, which is defined as a polymer in which substantially all structural units are composed of aromatic compounds. Examples of aromatic compounds as constituent components include: (A) at least one aromatic dicarboxylic acid, (B) at least one aromatic hydroxycarboxylic acid compound, (C) aromatic diol. At least one (D) aromatic dithiol, aromatic thiophenol.

at least one aromatic thiol carboxylic acid compound,
and (E) at least one of aromatic hydroxyamine and aromatic cyamine compounds.

These may be composed alone, but in most cases (A)
and (C), (A) and (D), (A) (B) and (C),
(A) (B) and (E) or (A) (B) (C) and (
E) etc.

As for the above aromatic dicarboxylic acid compound (A), terephthalic acid, 4,4-diphenyldicarboxylic acid, 4.4
'-triphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, diphenyl ether-4°4'-dicarboxylic acid, diphenoxyethane-4,4-dicarboxylic acid, diphenoxybutane-4,4°-dicarboxylic acid, diphenylethane -4,4'-dicarboxylic acid, isophthalic acid, diphenylether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, naphthalene-1,6 −
Aromatic dicarboxylic acids such as dicarboxylic acids or alkyls of the above aromatic dicarboxylic acids such as chloroterephthalic acid, dichloroterephthalic acid, bromo terephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, ethyl terephthalic acid, methoxyterephthalic acid, ethoxyterephthalic acid, etc. Alkoxy or halogen substituted products may be mentioned.

(B) As the aromatic hydroxycarboxylic acid compound,
4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6
-Hydroxy-2-naphthoic acid, 6-hydroxy-1-
Aromatic hydroxycarboxylic acids such as naphthoic acid or 3-
Methyl-4-hydroxybenzoic acid, 3,5-dimethyl-
4-hydroxybenzoic acid, 2.6-dinoethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3.5-dimethoxy-4-hydroxybenzoic acid,
6-hydroxy-5-methyl-naphthoic acid, 6-hydroxy-5-methoxy-naphthoic acid, 2-chloro-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 2,3-dichloro-4- Hydroxybenzoic acid, 3.
5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3-bromo-4-hydroxybenzoic acid, 6-hydroxy-5-chloro-2-naphthoic acid, 6-hydroxybenzoic acid -chloro-2-naphthoic acid, 6-hydroxyl5. Examples include alkyl, alkoxy or halogen-substituted aromatic hydroxycarboxylic acids such as fucyclo-2-naphthoic acid.

(C) Aromatic diols include 4,4-dihydroxydiphenyl, 3,3'-dihydroxydiphenyl, 4.
4-dihydroxytriphenyl, hydroquinone, resorcinol, 2,6-naphthalenediol, 4,4'-dihydroxydiphenyl ether, bis(4-hydroxyphenoxy)ethane, 3,3'-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2 Aromatic diols such as 2-his(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, or chlorohydroquinone, methylhydroquinone, t-butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chlororesorcinone , alkyl, alkoxy or halogen-substituted aromatic diols such as 4-methylresorcinol.

(Dl) As the aromatic dithiol, Hensen-1,4
-dithiol, Hensen-1,3-dithiol, 2.6
-naphthalene-dithiol, 2,7-naphthalene-dithiol, and the like.

(Dl) Aromatic mercaptocarphonic acids include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, 7-mercapto-2-naphthoic acid, and the like.

(D3) Aromatic mercaptophenol includes 4-mercaptophenol, 3-mercaptophenol, 6-mercaptophenol,
Examples include mercaptophenol and 7-mercaptophenol.

(E) Aromatics and droxamine, aromatic diamine compounds include 4-aminophenol, N-methyl-4-
Aminophenol, 1,4-phenylenediamine, N-
Methyl-1,4-phenylenediamine, N,N'-dimethyl-1,4-phenylenediamine, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminephenol, 4-amino- 1-naphthol, 4-amine-4'-hydroxydiphenyl, 4-amino-4-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-4
-Hydroxydiphenylsulfite, 4,4-diaminophenylsulfite (thiodianiline), 44゛-diaminodiphenylsulfone, 2,5-diaminotoluene,
Examples include 4,4'-ethylene dianiline, 4,4'-diaminodiphenoxyethane, 4,4-diaminodiphenylmethane (methylene dianiline), and 4,4'-diaminodiphenyl ether (oxydianiline).

The thermotropic liquid crystal polymer used in the present invention can be produced from the above compound by various ester forming methods such as melt acidolysis and slurry polymerization.

The thermotropic liquid crystal polymer used in the present invention is composed of a polymer segment in which a part of one polymer chain forms an anisotropic melt phase, and the remaining part is a thermoplastic resin that does not form an anisotropic melt phase. Also included are polymers composed of segments.

Also included are composites of multiple thermotropic liquid crystal polymers.

Among these thermotropic liquid crystal polymers, preferred are polymers or copolymers containing at least monomer units represented by the general formula.

Particularly preferred is a ternary copolyester mainly composed of 4-hydroxybenzoic acid, biphenol and phthalic acid.

The fired pigment in the present invention refers to a fired oxide pigment,
These are fired composite oxide pigments and cadmium red pigments.

The inorganic pigment of the present invention must be calcined. Here, firing is an essential step in the pigment manufacturing process itself, especially in the final step of the manufacturing process (excluding post-processing such as milling).
It means fired at a temperature of ℃ or higher. For example, in a pigment made of a complex oxide, 90%
The oxide is produced by firing at a temperature of 0°C or higher, usually 1000°C or higher. Also, CdS and CdSe
In the case of pigments consisting of a solid solution with
The solid solution is produced by firing at the above temperature.

As an example of an oxide calcined pigment, mention may be made of chromium oxide. Examples of composite oxide fired pigments include titanium yellow complex oxide, cobalt blue complex oxide, green complex oxide containing cobalt, nickel, and titanium as main components, and tan complex oxide containing zinc and iron as main components. complex oxide,
Examples include a dark brown complex oxide containing iron, nickel, and aluminum as main components, and a brown complex oxide containing zinc, iron, and chromium as main components.

An example of a cadmiret pigment is a red isosolute of CdS and [;dse as the main components, which is produced by a dry process.

The method of coloring the thermotropic liquid crystal polymer having a melting point of 300° C. or higher according to the present invention is not particularly limited, but may be a method of manufacturing a colored pellet by a color compounding method and molding it by injection molding or extrusion molding, or a method of molding it by extrusion kneading. A preferred method is to manufacture a color concentrate pellet, tri-blend it with a natural color (non-colored) pellet, and then process the resulting material. In either case, the extrusion kneading or molding process must be carried out at a high temperature close to the melting point, and the pigment must be heat resistant at this temperature and must have no or very slight effect on the deterioration of the haze resin. It is. For this reason, only calcined inorganic pigments are used. Among these, a brown complex oxide pigment with a spinel-type crystal structure containing zinc and iron, containing a titanium yellow pigment with a britellite-type and rutile-type crystal structure as its main components, and a spinel-type crystal structure containing cobalt, nickel, and titanium as its main components. It is preferable to use one selected from a green complex oxide pigment, a cobalt blue complex oxide pigment with a spinel type crystal structure, and a cadmium red pigment which is a solid solution of CdS and CdCe as main components, or a mixture thereof.

As mentioned above, the fully aromatic polyester polymer or copolymer of the present invention has a melting point of 300° C. or higher, which is extremely high.

That is, when a pigment is blended into a thermotropic liquid crystal polymer, the thermotropic liquid crystal polymer is naturally heated to around its melting point to be brought into a molten state. At that time, a large amount of moisture generated from the heated pigment and decomposition products such as pigment surface treatment agents cause a decrease in the strength and heat resistance of the product (molded article), which is a phenomenon peculiar to liquid crystal polymers that melt at high temperatures. . For this reason, in the present invention, an inorganic fired pigment is used that produces fewer desorbed products and decomposed products when heated.

Therefore, the amount of weight loss when heated to 400°C is 0.0% when converted to the weight ratio to the desired predetermined resin composition.
It is preferable that the amount is 0.05% by weight or less.

The weight loss on heating of the pigment is determined as the weight loss until the pigment reaches 400° C. when heated from room temperature at a heating rate of 10° C./minute using a normal TG (thermobalance).

Next, this weight loss on heating is converted into a weight ratio with respect to a predetermined resin composition for which the weight loss in 1/1 of the present invention is determined.

Since the liquid crystal polymer of the present invention has a high melting point of 300° C. or higher, it is important in the present invention to use a pigment that has a weight loss amount under such specific conditions.

The pigment content is preferably 0.2 to 60% by weight.

The content of the final product is particularly preferably from 0.5 to 20% by weight. When using a color concentrate, a color concentrate pellet with a pigment content of 60% by weight or less is manufactured, and this is tri-blended with a natural pellet during molding, and then a color concentrate pellet with a predetermined pigment content as in the previous example is produced. A method of obtaining the product is preferred.

If the pigment content is less than 0.2% by weight, a sufficient coloring effect cannot be obtained. Moreover, if the pigment content exceeds 60% by weight, the physical properties and heat resistance will not be sufficient, which is not preferable.

As for the surface treatment of the pigment, an inorganic or organic surface treatment agent may be applied to the extent that the properties targeted by the present invention are not impaired.

The particle size of the pigment is not particularly limited, but is usually 0.1 to 5μ.
is within the range of

In the present invention, the pigment may be used alone, or a plurality of pigments may be used in combination. It can also be used in combination with other pigments such as carbon black.

Only the pigment may be added to the composition of the present invention, or other additives may be added as necessary.

Various additives can be blended into the thermotropic liquid crystal polymer used in the present invention. That is, examples include inorganic fillers, organic fillers, stabilizers, antioxidants, ultraviolet absorbers, and pigments, dyes, or modifiers other than those defined in the present invention. Among these, inorganic fillers are particularly important and are often used to improve processability, physical properties, etc. Inorganic fillers include molybdenum disulfide, talc, mica, clay, sericite, calcium carbonate, calcium silicate, silica, alumina, aluminum hydroxide, calcium hydroxide, graphite, potassium titanate, glass fiber, carbon fiber, and There are various types of whiskers.

[Examples] The present invention will be further explained below with reference to Examples, but these Examples do not limit the scope of the present invention, but merely indicate preferred embodiments of the present invention.

First, the raw materials used in the Examples and Comparative Examples will be collectively explained.

1. Resin Resin A Terephthalic acid, 4-hydroxybenzoic acid, and 4,4
゛-A thermotropic liquid crystal polymer powder that is a tertiary copolyester of dihydroxyphenyl. Melting point: 400°C Resin B Powder of thermotropic liquid crystal polymer which is a quaternary copolyester of terephthalic acid, isophthalic acid, 4-hydroxybenzoic acid and 4,4'-dihydroxyphenyl.

Melting point 350°C2, glass fiber manufactured by Asahi Fiber Class ■ MFA 3, pigments shown in Table 1. In addition, regarding the amount of weight loss of the pigment,
Shown in the table.

<Examples 1-2> Resin, glass fiber, and pigment were mixed in the composition shown in Table 2, and kneaded and granulated using a twin-screw extruder (PCM-30 manufactured by Ikegai Iron Works) at a cylinder temperature of 355°C. .

The obtained resin pellet was injection molded using an injection molding machine (manufactured by Sumima Heavy Industries, Ltd., 5G-25) at a cylinder temperature of 350° C. to obtain a test piece.

Tensile test, Izot impact test and thermal deformation test are
The tests were conducted in accordance with ASTM-D638, ASTM-D256, and ASTM-D648, respectively. For the blistering test, test specimens were placed in an air oven at 260”C for 4 hours.
It was heated for a period of time and judged by the presence or absence of blistering.

These results are summarized in Table 2. As is clear from the table, the colored composition according to the present invention had sufficient mechanical strength and heat resistance, and also had a good appearance.

<Examples 3 to 11> Experiments were conducted in the same manner as in Example 1, except that the cylinder temperatures of the twin-screw extruder and injection molding machine were set to 405°C and 400°C, respectively.

The results are also shown in Table 2. As is clear from the table, the colored composition had sufficient mechanical strength and heat resistance, and also had a good appearance.

Comparative Examples 1 and 2> An experiment was conducted in the same manner as in Example 3 using the raw materials shown in Table 2.

The results are summarized in Table 2. As is clear from the table, these compositions have insufficient strength and heat resistance.

<Examples 12 to 14> Resin A and pigment were mixed in the composition shown in Table 3, and a cylinder temperature of 355 was mixed using a twin screw extruder (PCM-30).
The mixture was kneaded and granulated at ℃ to produce a color concentrate.

Next, resin and glass fiber were mixed in the composition shown in Table 3, and natural pellets were produced in the same manner.

This color concentrate and natural pellets were triblended in the proportions shown in Table 4, and injection molding and evaluation were performed in the same manner as in Example 1. The results are shown in Table 4. As is clear from the table, the composition had sufficient mechanical strength and heat resistance. Moreover, the appearance was also good with no color unevenness.

[Effects of the Invention] As described above, in the present invention, 0.2 to 60% by weight of an inorganic fired pigment is blended into a thermotropic liquid crystal polymer, which is a fully aromatic polyester with a melting point of 300°C or higher. Therefore, it is possible to color the composition of the same polymer without maintaining sufficient heat resistance and mechanical strength.
It can be put to practical use in a wide range of fields, and has the effect of dramatically expanding its uses.

Patent applicant: Japan Petrochemical Co., Ltd.

Claims (4)

[Claims] (1) 0.2 to 60 weight of an inorganic fired pigment is added to a thermotropic liquid crystal polymer which is a fully aromatic polyester polymer or copolymer containing at least a monomer unit represented by the following general formula and has a melting point of 300°C or higher. % of a colored polymer composition. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (2) The polymer composition according to claim 1, wherein the thermotropic liquid crystal polymer is composed of a copolymer mainly composed of 4-hydroxybenzoic acid, biphenol, and phthalic acid. (3) The amount of weight loss when the inorganic fired pigment is heated to 400°C is 0 when converted to the weight ratio to the resin composition.
．． The polymer composition according to claim 1 or 2, characterized in that the content is 0.5% by weight or less. (4) The main component of the inorganic fired pigment is a cobalt blue complex oxide, a titanium yellow complex oxide, a green complex oxide containing cobalt, nickel, and titanium as main components;
Tan-based composite oxide containing zinc and iron as main components, brown-based complex oxide containing zinc, iron, and chromium as main components, dark brown-based complex oxide containing iron, nickel, and aluminum as main components; 4. The polymer composition according to claim 1, wherein the polymer composition is a red solid solution of cadmium sulfide or cadmium selenide, or a mixture thereof.