JPS6336625B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyamide resin laminate structure having a strongly adherent aminoalkyd resin coating layer on its surface. Polyamide resin is widely used as a material for various industrial parts, but until now it has been used for internal mechanical parts such as gears, cams, and bearings, so painting has rarely been necessary. However, recently, attention has been focused on its excellent heat resistance and mechanical properties, and polyamide resin has been used for automotive exterior parts such as air spoilers, louvers, cowl top grilles, air outlet grilles, wheel caps, bumpers, etc. are being used. By the way, as a paint for automobile exterior parts,
Amino alkyd resin paint is usually used because of its excellent gloss, texture, hardness, weather resistance, and solvent resistance, but this paint has poor adhesion to polyamide resin, so it cannot be applied directly. I can't. Therefore, until now, when applying aminoalkyd resin paint to polyamide resin, the method used was to soak the surface in a treatment liquid such as a phosphoric acid solution to improve the adhesion to the aminoalkyd resin paint. . However, such a method of immersing in a treatment liquid requires post-treatment such as washing with water and drying, which increases the number of steps and has the drawback of causing dimensional changes due to water absorption. The present inventors have conducted extensive research in order to overcome these drawbacks of the conventional technology and develop a polyamide resin that can firmly adhere to the amino alkyd resin coating layer without any pretreatment. discovered that, unexpectedly, when a small amount of a surfactant, which had been conventionally used as a mold release agent or lubricant for plastics, was blended into polyamide resin, the adhesion between it and the amino alkyd resin paint significantly improved. ,
Based on this knowledge, the present invention was accomplished. That is, the present invention uses an adhesion improver selected from cationic and nonionic surfactants,
The object of the present invention is to provide a laminated structure characterized in that an aminoalkyd resin coating layer is formed on a polyamide resin substrate which has been added and molded in a proportion of 0.05 to 5% by weight. Examples of the polyamide resin used as a substrate in the present invention include polymers such as ε-caprolactam, aminocaproic acid, ω-laurinlactam, 11-aminoundecanoic acid, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, and dodecamethylenediamine. Diamines such as methylene diamine, adipic acid, azelaic acid, sebacic acid,
Examples include polycondensates with dicarboxylic acids such as dodecane-diacid and those based on copolymers of these monomers. This polyamide resin may contain rubbers, thermoplastic resins, and the like. Examples of these rubbers include ethylene propylene rubber, acrylonitrile butadiene rubber, styrene-butadiene block copolymer rubber and hydrogenated products thereof, styrene-isoprene block copolymer rubber and hydrogenated products thereof, and carboxylic acid modified products thereof. and mixtures thereof. Examples of thermoplastic resins include polyethylene, ethylene-vinyl acetate copolymer, polypropylene, carboxylic acid modified products thereof (including ionomer resin), acrylonitrile-butadiene-styrene copolymer, and mixtures thereof. be able to. Furthermore, if desired, an inorganic filler can be added to this polyamide resin for reinforcement.
Examples of this inorganic filler include powders such as calcium carbonate, calcium silicate, talc, kaolin, mica, titanium oxide, alumina, ferrite, silica, and carbon, as well as glass fiber, carbon fiber,
Examples include fibers such as metal fibers and boron fibers. These may be used alone, or two
You may use combinations of more than one species. In the present invention, it is necessary to use a cationic or nonionic surfactant as an adhesion improver. Examples of the cationic surfactant include monoalkyl Primary amines, secondary amines and tertiary amines such as amines, alkylmethylamines having an alkyl group having 8 to 18 carbon atoms, alkyldimethylamines having an alkyl group having 8 to 18 carbon atoms, and acetate salts thereof; Salts such as hydrochloride, dialkyldimethylammonium chloride with an alkyl group having 8 to 18 carbon atoms, alkyltrimethylammonium chloride, alkylimidazolium chloride, alkyldimethylbenzylammonium chloride, polyoxyethylenealkylmonomethylammonium chloride, alkylisoquinolide Nium chloride and their corresponding bromides, adducts of ethylene oxide with alkyl amines having an alkyl group having 8 to 18 carbon atoms, such as oxyethylene alkyl amine, polyoxyethylene alkyl amine, polyoxyethylene alkyl propylene diamine, 8 to 18 carbon atoms Mention may be made, for example, of alkylpyridinium chlorides having 18 alkyl groups and the corresponding bromides. In addition, various amines containing amide bonds, ester bonds, and ether bonds, quaternary ammonium salts, pyridinium salts, and amphoteric surfactants having cationic activity can also be used. Among these, quaternary ammonium salts are particularly preferred for improving adhesion. Next, examples of nonionic surfactants include carbon atoms of 8 to 18
polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkylate, having an alkyl group of
Mention may be made of polyoxyethylene sorbitan alkylate, sorbitan alkylate, alkyl diethanolamide, glycerin alkylate and polyoxyethylene polypropylene block copolymers. These adhesion improvers are added to the polyamide resin in a proportion ranging from 0.05 to 5% by weight.
If this amount is less than 0.05% by weight, the adhesion to the amino alkyd resin coating will be insufficient, and if it is more than 5% by weight, moldability will be reduced. This adhesion improver may partially decompose during molding of the substrate, but if used within the above range, it will fully exhibit its effect. The polyamide resin base of the present invention is prepared by adding a predetermined amount of an adhesion improver to the polyamide resin component described above, mixing the mixture using a ribbon blender, Henschel mixer, tumble mixer, etc., and then shaping the polyamide resin into the desired shape according to a conventional method. It is formed by molding into. The amino alkyd resin coating layer provided on the substrate formed in this manner is formed using a coating material consisting of a mixture of an alkyd resin and an amino resin. The alkyd resin used in this case is, for example, a condensate of a polycarboxylic acid such as maleic anhydride, phthalic anhydride, or isophthalic acid or an anhydride thereof and a polyhydric alcohol such as glycerin or pentaerythritol, or a condensate of a polyhydric alcohol such as glycerin or pentaerythritol. It is an oil-modified alkyd resin modified with fatty acids such as oil, linseed oil, castor oil, soybean oil, tall oil. On the other hand, amino resins include, for example, butoxymethylol urea and butoxymethylol melamine, which are made oil-soluble by etherifying a condensate of urea or melamine and formaldehyde with an alcohol such as butanol. In the present invention, to form the aminoalkyd resin coating layer on the substrate, commonly used coating methods such as brush coating, dip coating, spray coating, and electrostatic coating are used. The thus obtained laminated structure of the present invention has a polyamide resin base and an aminoalkyd resin coating layer firmly adhered to each other and does not easily peel off, so it can be used as an automotive exterior component or other material. It can be used suitably. Next, the present invention will be explained in more detail with reference to Examples. Note that the characteristic values in the examples were measured by the following method. (1) Adhesion (a) Normal state: In accordance with JISK5400-1979, a 1 mm square grid test was conducted to determine the area percentage that would not peel off. (b) After thermal shock; Thermal shock test (-30℃ x 1hr~90
℃ × 1 hr), a grid test was performed to determine the area percentage that did not peel off. Examples 1 to 4, Comparative Example 1 Nylon 66 (Leona manufactured by Asahi Kasei Corporation)
1300) and octadecyltrimethylammonium chloride (manufactured by NOF Corporation, cation AB)
After mixing 0.2% by weight (as cationic AB nonvolatile content) of 30% by weight of non-volatile content, it was dried at 80°C for 1 hour,
Volatiles were removed. This mixture was injection molded to produce a flat plate (length 120 mm, width 80 mm, thickness 3 mm).
This flat plate was coated with amino alkyd resin paint (manufactured by Kansai Paint Co., Ltd., Amirak No. 1000, White No.
531, diluted with special thinner (15 seconds/FC#4)) and left at room temperature for 30 minutes.
The mixture was cured by heating at 140°C for 30 minutes to obtain a laminated structure. The coating thickness of this product was approximately 40 μm. Table 1 shows the results of measuring the adhesion of this laminated structure.
Table 1 also shows the results of varying the blending amount. Examples 5 to 8 1-Hydroxyethyl 2- instead of octadecyltrimethylammonium chloride in Example 2
Alkyl (beef tallow) imidazoline quaternary salt (cation AR-4, manufactured by NOF Corporation, non-volatile content 40% by weight), oxyethylene dodecylamine (manufactured by NOF Corporation, Naimeen L-201, non-volatile content 100% by weight), poly Oxyethylene octyl phenol ether (manufactured by NOF Corporation, Nonion HS-
210, nonvolatile content 100% by weight) or octadecyltrimethylammonium chloride/polyoxyethylene octylphenol ether (nonvolatile content ratio 1/
A laminated structure was manufactured in the same manner as in Example 2 except that Example 1 was used, and the adhesion was measured. The results are shown in Table 1. Comparative Example 2 An anionic surfactant, sodium dodecylbenzenesulfonate (Nurex Powder F, manufactured by NOF Corporation, nonvolatile content 100% by weight) was used instead of the cationic surfactant of Example 2. A laminated structure was manufactured in the same manner as in Example 2, and the adhesion was measured. The results are shown in Table 1.

【table】

[Table] Examples 9 to 12, Comparative Examples 3 to 6 Glass fiber reinforced nylon 66 (Leona manufactured by Asahi Kasei Corporation) was used instead of nylon 66 in Example 1.
1300G), resin containing 30% by weight of calcium silicate in nylon 66 of Example 1, nylon of Example 1
66 mixed with 10% by weight of ethylene proprene rubber (EP51 manufactured by Japan EP Rubber Co., Ltd.) and 20% by weight of ionomer resin (Surlyn A1706 manufactured by DuPont), nylon 6 (CM1017 manufactured by Toray Industries, Inc.)
A laminated structure was manufactured in the same manner as in Example 1 except that the following was used, and the adhesion was measured. The results are shown in Table 2. In addition, the adhesion measurement results for those without octadecyltrimethylammonium chloride are also shown in the second table.
Shown in the table.

【table】

[Table] Polyamide resin moldings containing specific amounts of cationic surfactants and nonionic surfactants had excellent adhesion to aminoalkyd resins and were sufficiently suitable for practical use.

Claims (1)

[Claims] 1. On a polyamide resin base formed by adding an adhesion improver selected from cationic and nonionic surfactants at a ratio of 0.05 to 5% by weight,
A laminated structure characterized by forming an amino alkyd resin coating layer.