JPH042613B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for improving the adhesion of thermotropic liquid crystal polymer moldings. (Prior art) Thermotropic liquid crystal polymers have excellent properties such as heat resistance, chemical resistance, low coefficient of linear expansion, high elasticity, high strength, and self-extinguishing properties, and are useful for electronic components, IC sealing materials,
Applications are considered for optical fiber coating materials, chemical equipment parts, automobile-related parts, microwave oven containers, VTR parts, etc., and some of them have already been put into practical use, but molded products cannot be used because the surface is inert. Painting, printing, adhesion, plating, metal vapor deposition, etc. on the surface is difficult. Conventionally, when painting, printing, adhering, etc. the surface of plastic molded products, pretreatment is required.
Sandblasting, solvent treatment, chromic acid mixture treatment, corona discharge treatment, plasma treatment and the like have been proposed as these methods, but none of these methods is satisfactory for this thermotropic liquid crystal polymer. For example, sandblasting is a method of roughening the surface by bombarding the material with granular abrasives at high speed.
The granular abrasive material has insufficient staining effect on the work environment and products. Solvent treatment is a method in which the molded product is placed in organic solvent vapor and the surface of the molded product is etched.
There are no organic solvents that are sufficiently effective for thermotropic liquid crystal polymers. The chromic acid mixed solution treatment has problems such as the large burden required to render the treated waste liquid harmless. Further, corona discharge treatment cannot treat objects other than film-like materials, and plasma treatment has drawbacks such as high cost for processing equipment. OBJECTS OF THE INVENTION The purpose of the present invention is to overcome the above-mentioned drawbacks found in the surface treatment of thermotropic liquid crystal polymer moldings. (Structure of the Invention) The present invention is a liquid crystal polymer molding characterized in that the surface of a wholly aromatic polyester thermotropic liquid crystal polymer molding is irradiated with ultraviolet rays having a main action wavelength of 1849 Å using a synthetic quartz lamp. This is a method for improving the adhesion of objects. In the present invention, the term "method for improving the adhesion of a molded article" refers to a method for improving the adhesion of an object to be adhered to the surface of a molded article by means such as painting, printing, adhesion, plating, metal vapor deposition, or the like. The thermotropic liquid crystal polymer referred to in the present invention is a thermoplastically meltable wholly aromatic polyester that exhibits optical anisotropy when melted. Such a polymer exhibiting optical anisotropy when melted has a property in which the polymer molecular chains take a regular parallel arrangement in the melted state. The properties of the optically anisotropic melt phase can be confirmed by conventional polarization testing using crossed polarizers. Thermotropic liquid crystal polymers are typically made from monomers that are elongated, flat, and have multiple chain extensions along the long chain of the molecule that are rigid and in either coaxial or parallel relationships. . The constituent components of the polymer that form the optically anisotropic melt phase as described above include (A) at least one aromatic dicarboxylic acid compound;
(B) at least one aromatic hydroxycarboxylic acid compound; (C) at least one aromatic diol compound; (D) aromatic diol, aromatic thiophenol, aromatic thiol carboxylic acid compound; (E) At least one of aromatic hydroxyamine and aromatic diamine 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)
It is constructed by combining (B), (C) and (E), etc. The above (A1) aromatic dicarboxylic acid compounds include terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid,
2,6-naphthalene dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,4'-dicarboxylic acid, diphenylethane-4, 4'-dicarboxylic acid, isophthalic acid, diphenyl ether-3,3'-
dicarboxylic acid, diphenoxyethane-3,
3'-dicarboxylic acid, diphenylethane-3,
Aromatic dicarboxylic acids such as 3'-dicarboxylic acid, naphthalene-1,6-dicarboxylic acid or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid, dimethylterephthalic acid, ethylterephthalic acid, methoxyterephthalic acid, ethoxy Examples include alkyl, alkoxy or halogen-substituted terephthalic acid. (B) Aromatic hydroxycarboxylic acid compounds include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid,
Aromatic hydroxycarboxylic acids such as 6-hydroxy-1-naphthoic acid or 3-methyl-4-hydroxybenzoic acid, 3,5-dimethyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-Methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5-methyl-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-hydroxy-7-chloro-2-naphthoic acid, 6-hydroxy-5,7-dichloro-2-
Examples include alkyl, alkoxy or halogen-substituted aromatic hydroxycarboxylic acids such as naphthoic acid. (C1) 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, 2,2'-bis(4- Aromatic diols such as hydroxyphenyl)propane, 2,2'-bis(4-hydroxyphenyl)methane, or chlorohydroquinone, methylhydroquinone, 1-butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4 Examples include alkyl, alkoxy or halogen substituted aromatic diols such as -chlororesorcin and 4-methylresorcin. (D1) As aromatic diol, benzene 1,4
-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, 2,
Examples include 7-naphthalene-dithiol. (D2) As aromatic mercaptocarboxylic acid, 4
-Mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, 7
-mercapto-2-naphthoic acid and the like. (D3) As aromatic mercaptophenol, 4
-Mercaptophenol, 3-mercaptophenol, 6-mercaptophenol, 7-
Examples include mercaptophenol. (E) Aromatic hydroxyamines and 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-aminophenol, 4-amino-1-
Naphthol, 4-amino-4'-hydroxydiphenyl, 4-amino-4'-hydroxyphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-4'-hydroxydiphenyl sulfide , 4,4'-diaminophenyl sulfide (thiodianiline), 4,4'-diaminodiphenylsulfonic acid, 2,5-diaminotoluene, 4,4'-ethylenedianiline, 4,
Examples thereof include 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 compounds by various ester forming methods such as melt acidolysis and slurry polymerization. In the thermotropic liquid crystal polymer used in the present invention, a part of one polymer chain is composed of a polymer segment that forms an anisotropic melt phase, and the remaining part is a thermoplastic liquid crystal polymer that does not form an anisotropic melt phase. Also included are polymers composed of segments of resin.
Also included are composites of multiple thermotropic liquid crystal polymers. Among these thermotropic liquid crystal polymers,
Preferably, at least the general formula A (co)polymer containing monomer units represented by It has particularly excellent properties such as heat resistance, chemical resistance, and low coefficient of linear expansion, and it is possible to effectively surface activate fully aromatic polyesters that are difficult to paint, print, etc. In the present invention, the surface of the liquid crystal polymer molded product as described above is irradiated with ultraviolet rays. In this case, the molded product is a mold, film, sheet, plate, pipe,
These are molded products of various shapes such as fibers. The ultraviolet rays irradiated onto the surface of the liquid crystal polymer molded article are ultraviolet rays having a main wavelength of 1849 Å.
This ultraviolet light is obtained from a light source of a high-purity synthetic quartz lamp. In the present invention, it is preferable to treat the surface with an ultraviolet absorbing solvent before irradiating it with ultraviolet rays. The ultraviolet-absorbing solvent may have an ultraviolet-absorbing structure within its molecules, or may be one in which an additive having ultraviolet-absorbing properties is dissolved in the solvent. Specific examples of the former include benzene, toluene,
There are aromatic solvents such as xylene, halogenated carbon solvents such as carbon tetrachloride, tetrachloroethylene, trichloroethylene, and trichlorotrifluoroethylene, and ester solvents such as acrylic esters. Examples of the latter include acetophenone derivatives, Examples include aromatic solvents, halogenated hydrocarbon solvents, ester solvents, etc. in which photosensitizers such as benzophenone derivatives, benzoin derivatives, sulfide derivatives, and diazonium salt derivatives are dissolved. In the present invention, the molded liquid crystal polymer may be heated in advance and irradiated, and even when treated with an ultraviolet absorbing organic solvent, it is preferable to heat the molded liquid crystal polymer in advance. The heating temperature is 30°C or higher, preferably 50°C or higher, and lower than the melting point. The treatment time is within 20 minutes, preferably from 5 seconds to 5 minutes. It is preferable that the distance between the molded product and the light source be close, and the distance between the molded product and the light source is usually 1 to 100 cm. Further, in the present invention, it is possible to heat the liquid crystal polymer molded product in advance and bring it into contact with the organic solvent, but since heating the solvent is accompanied by the generation of steam, caution is required since there is a risk of fire and the human body. Various additives can be blended into the thermotropic liquid crystal polymer used in the present invention. These include inorganic fillers, organic fillers, stabilizers, antioxidants, UV absorbers, pigments, dyes, other polymers, modifiers, and the like. Among these, inorganic fillers are particularly important and are often used to improve processability, physical properties, etc. Inorganic fillers include talc,
Mica, clay, sericite, calcium carbonate, calcium silicate, silica, alumina, aluminum hydroxide, magnesium hydroxide, graphite,
There are titanium sankali, glass fiber, carbon fiber, various whiskers, etc. (Effects of the Invention) According to the present invention, the surface of a thermotropic liquid crystal polymer molded product is highly activated, making it suitable for surface treatments such as painting, printing, adhesion, and metal vapor deposition. The unique effects produced by the present invention are as follows. (1) Products treated according to the present invention are beautiful because the coating film, printed film, etc. attached to the surface has good uniformity, and the adhesion of the film to the molded product is strong. (2) The treatment method does not involve complicated chemical operations, and there are no steps such as washing with water or undercoating after treatment, so the operation is simple and the treatment time is short. (3) Ultraviolet irradiation equipment is inexpensive, so equipment costs are low. (4) Unlike corona discharge treatment, materials other than film can also be treated. (5) Processing time is short because the main working wavelength is 1849 Å. (Example) The present invention will be explained in more detail with reference to Examples. Example 1 An injection molded body of Xydar (trade name of Nippon Petrochemical Co., Ltd.) SRT-300, a thermotropic liquid crystal polymer consisting of terephthalic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxydiphenyl In this case, the ultraviolet rays of a synthetic quartz glass lamp having a main working wavelength of 1849 Å are emitted from a distance of 50 mm.
Irradiated for minutes. This board was spray-painted using an acrylic resin paint (acrylic acid ester as the main component, dispersion medium being a ketone solvent) 30 minutes after treatment. Adhesion was examined after the coating was dried in an air atmosphere for approximately 24 hours. Put 11 2mm wide cross cuts vertically and horizontally into the paint film, press cellophane tape (Mitsubishi Uni Cellophane Tape 18) onto the paint film, and evaluate the adhesion by the ratio of the number of remaining cuts after peeling it off (remaining number of cuts / (original number of stitches x 100). Table 1 shows the results.
Shown below. Example 2 Xider as a thermotropic liquid crystal polymer
The procedure was the same as in Example 1 except that FC110 (containing 40% glass fiber) was used. The results are shown in Table 1. Example 3 Xydar as a thermotropic liquid crystal polymer
The same method as in Example 1 was followed except that FC130 (containing 50% talc) was used. The results are shown in Table 1. Example 4 Xider as a thermotropic liquid crystal polymer
A molded body using FC110 is heated to 60℃, and a 50:50 (volume ratio) of carbon tetrachloride and tetrachlorethylene is heated.
After being immersed in the mixed solution for 5 minutes and dried for 5 minutes, it was irradiated with ultraviolet rays in the same manner as in Example 1, and the subsequent evaluation was performed. The results are shown in Table 1. Example 5 Example 4 except that the ultraviolet irradiation time was 1 minute.
UV irradiation was performed in the same manner as above, and subsequent evaluation was performed. The results are shown in Table 1. Example 6 In place of Xyder FC110 in Example 4, Vectra A130 (glass fiber 30
%, manufactured by Polyplastics Co., Ltd.) in the same manner as in Example 1, and the results are shown in Table 1. Example 7 In place of Vectra in Example 6, Rodudran, a thermotropic liquid crystal polymer consisting of 4-hydroxybenzoic acid and polyethylene terephthalate, was used.
Evaluation was performed in the same manner as in Example 6 using LC2000 (manufactured by Unitika), and the results are shown in Table 1. Comparative Example 1 The same method as in Example 2 was carried out except that ultraviolet irradiation was not performed. The results are shown in Table 1. Comparative Example 2 The same method as in Example 4 was carried out except that ultraviolet irradiation was not performed. The results are shown in Table 1.

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Claims (1)

[Scope of Claims] 1. A liquid crystal polymer molded product characterized in that the surface of the fully aromatic polyester thermotropic liquid crystal polymer molded product is irradiated with ultraviolet rays having a main working wavelength of 1849 Å using a synthetic quartz lamp. Method for improving adhesion. 2. The method according to claim 1, wherein the thermotropic liquid crystal polymer molded product is heated when the surface of the molded product is irradiated with the ultraviolet rays. 3. The method according to claim 1 or 2, characterized in that when irradiating the surface of the thermotropic liquid crystal polymer molded article with the ultraviolet rays, the molded article is brought into contact with an ultraviolet absorbing solvent in advance. 4. According to claim 3, when bringing the thermotropic liquid crystal polymer molded product into contact with the ultraviolet absorbing solvent, the molded product and/or the solvent are heated and the molded product is immersed or treated with steam. the method of. 5. The method according to any one of claims 1 to 4, wherein the thermotropic liquid crystal polymer is a (co)polymer containing at least monomer units represented by the following general formula. general formula