JPH01236246A - Surface activation of thermotropic liquid crystal polymer - Google Patents

Abstract

PURPOSE:To improve the surface activity of a thermotropic liquid crystal polymer molding so that it is capable of painting, printing, bonding, plating, metallizing, etc., by irradiating said surface with specified ultraviolet rays. CONSTITUTION:A molding of a thermotropic liquid crystal polymer which is a (co)polymer having, desirably, monomer units of the formula and optionally heated to 30 deg.C or above is brought into contact with an optionally heated ultraviolet-absorbing solvent and irradiated with ultraviolet rays having a dominant wavelength of 1,849Angstrom at a distance of 1-100cm within 20min, desirably, 5sec-5min.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for surface activating thermotropic liquid crystal polymers.

(Conventional technology) Thermotropic liquid crystal polymer has heat resistance, chemical resistance,
It has excellent properties such as low R expansion coefficient, high elasticity, high strength, and self-extinguishing properties, and is suitable for electronic parts, IC sealing materials, optical fiber coating materials, chemical equipment parts, automobile-related parts, microwave oven containers, Applications to VTR parts, etc. have been considered, and some of them have already been put into practical use, but because the surface is inert, it is difficult to paint, print, adhere, plate, metal vapor deposit, etc. on the surface of molded products.

Conventionally, pretreatment is required when painting, printing, adhering, etc. on the surface of plastic molded products, and these methods include sundblasting, solvent treatment, chromic acid mixture treatment, corona discharge treatment, and plasma treatment. However, none of these methods is satisfactory for this thermotropic liquid crystal polymer.

For example, sandblasting is a method in which a granular abrasive material is collided with a material at high speed to roughen the surface, and the granular abrasive material has an insufficient effect of staining the work environment and products.

Solvent treatment is a method in which the molded product is placed in organic solvent vapor to etch the surface of the molded product, but there is no organic solvent that is effective enough 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.

Furthermore, corona discharge treatment cannot treat objects other than those in the form of films, and unlike plasma treatment 1, it has disadvantages such as the large cost required for treatment equipment.

(Object of the invention) The object of the present invention is to overcome the above-mentioned drawbacks observed in the surface treatment of thermotropic liquid crystal polymer moldings.

(Structure of the Invention) The present invention is a method for activating the surface of a liquid crystal polymer, which is characterized in that the surface of a thermotropic liquid crystal polymer molded article is irradiated with ultraviolet rays having a main wavelength of action of 1849 nm.

The thermotropic liquid crystal polymer referred to 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 polymer molecular chains take a regular parallel arrangement in the melted state. The properties of the optically anisotropic molten phase can be confirmed by conventional polarization testing using crossed polarizers.

Thermotropic liquid crystal polymers are generally made from monomers that are elongated, flat, and have multiple chain extension bonds in either rigid, coaxial or parallel relationships along the long chains of the molecules.

The constituent components of the polymer that form the optically anisotropic melt phase as described above include (at least one of phantom aromatic dicarboxylic acids and alicyclic dicarboxylic acid compounds; (B) aromatic hydroxycarboxylic acid compounds; (C) At least one type of aromatic dione ring diol, aliphatic diol type compound, (D) At least one type of aromatic dithionoaromatic thiophene aromatic thiol carboxylic acid type compound, (E
) Aromatic compounds, droxyamines, and at least one type of aromatic diamine compounds. These may be composed of one person, but most are (person) and (C), (enter) and F.
D), (person) (B) and (C), (person) (B) and (E),
Alternatively, it is configured by combining (A), (B), (C) and (E), etc.

Examples of the aromatic dicarboxylic acid compounds (person 1) include terephthal 7319.4.4'-diphenyldicarboxylic acid, 4.4'-)diphenyldicarboxylic acid, 2.6-naphthalene dicarboxylic acid, and 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-343'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, naphthalene-
Aromatic dicarboxylic acids such as 1,6-dicarboxylic acids or alkyl, alkoxy or halogens of chloroterephthalic acid, dichloroterephthalic acid, bromo terephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, ethyl terephthalic acid, methoxyterephthalic acid, ethoxyterephthalic acid Examples include substituted products.

(λ2) Alicyclic dicarboxylic acids include trans-1,
Alicyclic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, or trans-1,
Examples include alkyl, alkoxy or halogen substituted products of the above-mentioned ring dicarboxylic acids, such as 4-(1-methyl)cyclohexanedicarboxylic acid and trans-1,4-(1-chloro)diclohexanedicarboxylic acid.

(B) As the aromatic hydroxycarboxylic acid compound,
4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6
-Hydroxy-2-naphthoic acid, 6-hydroxy-1-
Hydroxycarboxylic acids such as 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-hydroxy Benzoic acid, 3,5
-Dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3-bromo-4- and doro;h benzoic acid, 6- and droxy-5-chloro-2-naphthoic acid, 6 Examples include alkyl, alkoxy or halogen-substituted aromatic hydroxycarboxylic acids such as -hydroxy-7-chloro-2-naphthoic acid and 6-hydroxy-5,7-dichloro-2-naphthoic acid.

(C1) Aromatic diols include 4.4'-dihydroxydiphenyl, 3.3'-dihydroxydiphenyl,
4.4'-dihydroxytripheninohydroquinone, resorcinol, 2,6-naphthalenediol, 4.4'
-dihydroxydiphenyl ether bis(4-hydroxyphenoxy)ethane, 3.3'-dihydroxydiphenyl ether, 1. Tonaphthalene diol, 2.2'
-bis(4-hydroxyphenyl)furopane, 2.2'
- Aromatic diols such as bis(4-hydroxyphenyl)methane or aromatic diols such as chlorohydroquinone, methylhydroquinone, 1-butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chlororesorcinol, 4-methylresorcinol, etc. Examples include alkyl, alkoxy or halogen substituted products.

(C2) As the alicyclic diol, trans-1,4-
Cyclohexanediol, cis-1,4-cyclohexanediol, trans-1,4-cyclohexane dimetatool, cis-1,4-cyclohexane dimetatool,
trans-1,3-cyclohexanediol, cis-1
, 2-cyclohexanediol, trans-1,3-cyclohexane dimetatool or trans-1,4-(1-methyl)cyclohexanediol, trans-1,4-(1-chloro)cyclohexane Examples include alkyl, alkoxy or halogen substituted alicyclic diols such as diols.

Examples of the (C3) II aliphatic diol include linear or branched aliphatic diols such as ethylene glycol, 1,3-propanediol, ], 4-butanediol, and neopentyl glycol.

(Dl) As the aromatic dithiol, benzene-1,4
-dithiol, benzene-1,3-dithiol, 2,6
-naphthalene-dithiol, 2,7-naphthalene-dithiol, and the like.

(D2) Aromatic mercaptocarboxylic 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) Aromatic hydroxyamine and aromatic diamine compounds include 4-aminophenol, N-methyl-4-
Aminophenol, 1,4-phenylenediamine, N-
Methyl-1,4-phenyl-diamine, N,N'-dimethyl-1,4-phenyl-diamine, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-amino Phenol, 4-amino-1-naphthol, 4-amino-4'-hydroxyphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-7droxydiphenylmethane, 4-amino-4
'-Hydroxydiphenyl sulfide, 4.4'-diaminophenyl sulfide (thiodianiline), 4゜4
'-Diamino diphenyl sulfone, 2,5-diaminotoluene, 4,4'-ethylene dianiline, 4,4'-diaminodiphenoxyethane, 4,4'-diaminodiphenylmethane (methylene dianiline), 'p''-
Examples include amino diphenyl ether (oxydianiline) and the like.

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 includes a thermoplastic resin in which 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 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, it is preferable to use wholly aromatic polyesters, which retain physical properties and are difficult to paint, print, etc., and can be effectively surface activated.

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 molded product of various shapes such as a molded product, a film, a sheet, a plate, a pipe, and a tS fiber.

The ultraviolet rays irradiated onto the surface of the liquid crystal polymer molded product are 18
This is ultraviolet light whose main wavelength of action is on 49 people. This ultraviolet light is obtained from a light source such as 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 aromatic solvents such as benzene, toluene, and xylene, halogenated carbon solvents such as carbon tetrachloride, tetrachloroethylene, trichloroethylene, and trichlorotrifluoroethylene, and ester solvents such as acrylic esters. Examples of the latter include photosensitizers such as acetophenone conductors, penzofuninone conductors, benzoin derivatives, sulfide derivatives, and diazonium salt derivatives; dissolved aromatic solvents; halogenated hydrocarbons; There are solvents, ester solvents, etc.

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.
It must be done abnormally and below the melting point.

The treatment time is within 20 minutes, preferably from 5 seconds to 5 minutes.

The closer the distance between the molded object and the light source, the better, and usually 1~
It should be done in the 1100e range.

Further, in the present invention, it is possible to heat the molded product of the liquid crystal polymer 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.

It would be possible to incorporate lewd additives 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, calcilum carbonate, calcilum silicate, silica, alumina, aluminum hydroxide, magnesium hydroxide, graphite, titanium sankali, and glass! A4L carbon fiber, various whiskers, etc. are available.

(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 film adheres firmly to the molded product.

(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) Since the ultraviolet irradiation device is inexpensive, the equipment cost is low.

(4) Unlike corona discharge treatment, materials other than film can also be treated.

(Processing time is short because the main working wavelength is 511849A light.

(Example) The present invention will be explained in more detail with reference to Examples.

Example-1 Terephthalic acid, 4-hydroxybenzoic acid, and 4,4'
- Xider, a thermotropic liquid crystal polymer consisting of dihydroxydiphenyl (trade name of Nippon Petrochemical Co., Ltd.)
The injection molded product of SRT-300 was irradiated with ultraviolet light from a synthetic quartz glass lamp having 1849A as the main working wavelength for 5 minutes from a distance of 50+ m.

This board was coated with an acrylic resin paint (acrylic ester as the main component, using a dispersion medium (ketone solvent) for 3 days after treatment.
o! The spray paint was applied after + time had elapsed.

Adhesion was examined after the coating was allowed to dry in an air atmosphere for about 24 hours. 2mm wide cross cut on the coating film
Insert 11 tapes at a time, press cellophane tape (Mitsubishi Uni Cellophane Tape 18) onto the coating film, and determine the adhesion by the ratio of the number of remaining tapes after peeling off (number of remaining tapes/original number of tapes x 100).
) was expressed. The results are shown in Table 1.

Example-2 Xydar PCII as a thermotropic liquid crystal polymer
The same method as Example 1 was carried out except that O (containing 40% glass fiber) was used. The results are shown in Table 1.

Example-3 Zygu FC13 as thermotropic liquid crystal polymer
Example-1 except that 0 (contains 50% talc) is used.
I did it the same way. The results are shown in Table 1.

Xider PCII as a thermotropic liquid crystal polymer
The molded body using O was heated to 60°C, immersed in a 50:50 (volume ratio) mixture of carbon tetrachloride and tetrachloroethylene for 5 minutes, dried for 5 minutes, and exposed to ultraviolet light in the same manner as in Example-1. irradiation and subsequent evaluation. The results are shown in Table 1.

Example 5 Ultraviolet rays were irradiated in the same manner as in Example 4, except that the ultraviolet irradiation time was 1 minute, and subsequent evaluation was performed. Table 1 shows the results.
Shown below.

Example-6 Instead of Xydar PCIIO in Example-4, Vectra A130 (containing 30% glass fiber, a thermotropic liquid crystal polymer consisting of 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and terephthalic acid) was used. Polyplastics Co., Ltd.) was used in the same manner as in Example 1, and the results are shown in Table 1.

Example 7 Instead of Vectra in Example 6, Rodlan LC2000 (manufactured by Unitika Co., Ltd.), which is a thermotropic liquid crystal polymer made of 4-hydroxybenzoic acid and polyethylene terephthalate, was used and evaluated in the same manner as in Example 6. The results are shown in Table 1.

Comparative Example-1 The same method as Example-2 was carried out except that ultraviolet irradiation was not performed. The results are shown in Table 1.

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.

Table 1

Claims (6)

[Claims] (1) 1 on the surface of the thermotropic liquid crystal polymer molded product.
A method for activating the surface of a liquid crystal polymer, which comprises irradiating ultraviolet rays having a main wavelength of 849A. (2) The surface activation method according to claim 1, wherein the molded article is heated when the surface of the thermotropic liquid crystal polymer molded article is irradiated with the ultraviolet rays. (3) The method according to claim (1) or claim (2), characterized in that when the surface of the thermotropic liquid crystal polymer molded product is irradiated with the ultraviolet rays, the molded product is brought into contact with an ultraviolet absorbing solvent in advance. Surface activation method. (4) 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 surface activation method described in . (5) The surface activation according to any one of claims (1) to (4), wherein the thermotropic liquid crystal polymer is a (co)polymer containing at least a monomer unit represented by the following general formula: Method. General formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (6) Any one of claims (1) to (5), wherein the thermotropic liquid crystal polymer is a wholly aromatic polyester.
The surface activation method described in Section.