JPH06254485A - Production of scratch-resistant light permeable molded product having embossed patterns on its surface - Google Patents

Abstract

PURPOSE:To enhance production efficiency, in the production of the title molded product for a wall, by spraying a crosslinkable compd.-containing org. solvent paint on a composite object obtained by thermally fusing a transparent thermoplastic resin film to a light permeable sheet to form an uneven surface and subsequently curing the paint. CONSTITUTION:A transparent thermoplastic resin film composed of an acrylic resin film containing an ultraviolet absorber is laminated to at least one surface of a transparent sheet 1 composed of polycarbonate to form a composite. Then, org. solvent paint containing a crosslinkable compd. is applied to the transparent thermoplastic resin film 2 to form an uneven shape on the surface of the film 2 and the coated film 2 is cured to form a film 3. This org. solvent paint is prepared by adding 10-40 pts.wt. of an ester type compd. to 100 pts.wt. of a crosslinkable compd. such as trimethylol melamine. The thermal fusion of the transparent thermoplastic resin film 2 is performed under tension of 5-15kgf/m.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a surface of a substrate for use in various molded articles such as interior walls, windows, blinds, ornaments, exterior walls of buildings, car parts, recreational vehicles, etc. The present invention relates to a translucent resin molded product having an excellent embossed pattern, particularly a polycarbonate resin molded product having weather resistance.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins typified by glass, thermosetting acrylic resin and vinyl chloride, acrylic resin, and polycarbonate resin are used for daylighting materials of various structures, automobile parts, and various decorations because of their optical transparency. Widely used as a product.

However, with the increase in the number of buildings and the increase in density in urban areas, sunlight is reflected, the surrounding residents feel dazzling, and from the viewpoint of protecting privacy, while maintaining a high total light transmittance, There is an increasing need for a daylighting material with reduced visibility by suppressing surface gloss and lowering parallel light transmittance.

As a method of keeping visibility low while keeping the total light transmittance high, an embossed pattern may be imparted to the surface of a translucent material like frosted glass in terms of glass, for example, an emboss roll on a resin plate. A method of mechanically forming an embossed pattern on a smooth surface and optically scattering light (JP-A-63-151382, JP-A-64-85232), and processing of the embossed pattern on the surface A method of pouring a light-transmitting material into a mold subjected to heat treatment and shaping (Japanese Patent Laid-Open No. 49-45946 and Japanese Patent Laid-Open No. 53-288).
55, JP-A-53-133267), or a method of applying a coating material containing an inorganic filler or an organic filler that scatters and absorbs light onto the surface of a light-transmitting material (JP-A-52-20857). Japanese Patent Laid-Open No. 3-5884
No. 0) is used.

However, according to the above methods and, only a plate shape or a very simple shape can be formed, the shape of the molded body is limited, and a special shape or device is required.
Productivity is also low. In the above method, the addition of various fillers impairs the original weather resistance, scratch resistance, and chemical resistance of the paint.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently producing a translucent molded article having an embossed pattern on the surface, which is excellent in weather resistance, scratch resistance and chemical resistance. is there.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have incorporated a crosslinkable compound into a translucent laminated composite sheet in which a transparent thermoplastic resin film is heat-fused at a constant tension on at least one surface. When the organic solvent paint is spray-coated, the coated transparent thermoplastic film is soaked in the organic solvent paint, which causes unevenness in the initially uniform film thickness. It was found that an embossed pattern was formed. Therefore, in order to fix in that state, the cross-linkable compound-containing organic solvent coating is surface-cured by heat or ionizing radiation irradiation to have an embossed pattern on the surface excellent in weather resistance, scratch resistance, and chemical resistance. The present invention has been completed by finding that a translucent molded product can be obtained.

That is, the present invention is as follows. (1) An organic solvent paint containing a crosslinkable compound is spray-coated on a laminated composite in which a transparent thermoplastic resin film is heat-sealed on at least one surface of a translucent sheet,
A method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface, which comprises curing the organic solvent paint after producing an uneven shape on the surface.

(2) The light-transmissive sheet is a thermoplastic resin, and the transparent thermoplastic resin film is heat-sealed, and then molded into an arbitrary shape, and an organic solvent paint containing a crosslinkable compound is formed in the molded product. A method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to the above (1), which is spray-coated.

(3) The method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to the above (1) or (2), wherein the translucent sheet is a polycarbonate resin.

(4) The surface of any one of the above (1), (2) and (3), wherein the tension when heat-sealing the transparent thermoplastic resin film is in the range of 5 to 15 kgf / m. A method for producing a scratch-resistant translucent molded article having an embossed pattern.

(5) The transparent thermoplastic resin film is an acrylic resin film containing an ultraviolet absorber, and the surface is embossed on any one of the above (1), (2), (3) and (4). A method for producing a scratch-resistant translucent molded article having a pattern.

(6) Any one of the above (1), (2), (3), (4) and (5), wherein the organic solvent paint containing a crosslinkable compound contains an ionizing radiation crosslinkable curable compound as a main component. A method for producing a scratch-resistant translucent molded article having an embossed pattern on its surface.

(7) In an organic solvent paint containing a crosslinkable compound, 10 parts by weight or more and 40 parts by weight or less of an ester compound is added to 100 parts by weight of the crosslinking compound. ), (3), (4), (5), (6)
5. A method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to any one of 1.

The present invention can be applied to a wide range of transparent sheets. Specifically, it is a plate-shaped molded product of an inorganic translucent material typified by glass and quartz glass and a resin translucent material typified by polyvinyl chloride resin, acrylic resin and polycarbonate resin.

As the transparent thermoplastic resin film which is heat-sealed to these plate-shaped moldings, acrylonitrile-styrene copolymer resin (AS resin), butadiene-styrene
Methyl methacrylate copolymer resin (MBS resin), methacrylic / styrene copolymer resin, polycarbonate resin,
Amorphous resins such as polymethylmethacrylate resin, polystyrene resin, and polyvinyl chloride resin, which are inferior in solvent resistance, are desirable, and the thickness thereof is preferably in the range of 50 to 100 μm in view of the size of the embossed pattern to be generated and the cost. .

Further, a transparent thermoplastic resin film is heat-sealed to a plate-shaped molded product as a base material under a constant tension.
As the method, it is desirable to use a continuous pressure bonding method using a pressure roll during the on-line or off-line formation of the light-transmitting sheet as the base material.

At that time, the tension applied to the transparent thermoplastic resin film is 5 to 15 kgf / m, preferably 8 to 10 kgf / m.
It is necessary to perform heat fusion in the range of m. The reason is that when the tension is less than 5 kgf / m, wrinkles are generated in the transparent thermoplastic resin film at the time of application, and even if the organic solvent paint containing the crosslinkable compound is spray-coated, it may cause an embossed pattern. In some cases, uneven thickness does not occur.

When the tension exceeds 15 kgf / m, when the organic solvent paint containing the crosslinkable compound is spray-coated, the thickness unevenness generated in the coated thermoplastic resin film is large, and at the thinnest place, the thickness is large. Is 1
The thickness is 0 μm or less, and even when a thermoplastic resin film containing an ultraviolet absorber is used, the effect of imparting weather resistance to the substrate may not be exhibited.

There is no problem if the substrate is a material such as glass that does not discolor even when exposed to sunlight, but in the case of a substrate that discolors when exposed to sunlight, a transparent thermoplastic resin film contains an ultraviolet absorber. By doing so, it is possible to prevent discoloration of the substrate and impart weather resistance. As a base material lacking in weather resistance,
Although there is a polycarbonate resin, in this case, as the thermoplastic film containing an ultraviolet absorber imparting weather resistance, there is an acrylic resin film, specifically, Kanefuchi Chemical Co., Ltd. trade name "Sanduren", The Mitsubishi Rayon Co., Ltd. trade name "Acryprene" is commercially available.

As the crosslinkable compound contained in the organic solvent paint, a melamine-based cured product represented by trimethylolmelamine, hexamethylolmelamine, butoxymethylolmelamine, and etherified methylmelamine can be used by using a thermosetting method. What is formed, tetraethoxysilane, triethoxymethylsilane, triethoxyphenylsilane, alkoxysilanes typified by trimethylphenylsilane, or a part of the functional group thereof is -CH =
CH _2, -CH ₂ -NH _2,

[Chemical 1] _{-OCO-CCH 3 = CH 2,} -CH 2 OH, -CH 2 SH
Trifunctional or tetrafunctional organosilane substituted with a reactive functional group such as is known, and is widely used in general.

Similarly, as the crosslinkable compound, there is one using an ionizing radiation curing method, and examples thereof include unsaturated polyester, polyether acrylate, polyester acrylate, epoxy acrylate, urethane acrylate,
Ionizing radiation-curable compounds such as spiro acetal acrylate and polybutadiene polythiol polyene can be used.

These ionizing radiation curable compounds further include bifunctional monomers such as neopentyl glycol diacrylate, tripropylene glycol diacrylate,
Diethylene glycol diacrylate, 1,6-hexanediol diacrylate, etc., or trifunctional monomers such as trimethylolpropane triacrylate,
Polyfunctional monomers such as pentaerythritol triacrylate and dipentaerythritol hexaacrylate can be mixed and used. Other than this, tetrafunctional, pentafunctional or hexafunctional monomers can also be used.

In the above-mentioned ionizing radiation-curable coating material, in addition to the polyfunctional monomer added as necessary, when it is cured by ultraviolet irradiation, a photoinitiator such as acetophenones, benzophenone, Michler's ketone, benzoin, benzylmethyl is used. Ketal, benzoyl benzoate, α-
It is advisable to add amyloxime ester, tetramethyl thiuram sulfide, thioxanthones and the like and sensitizers such as n-butylamine, triethylamine and tri-n-butylphosphine.

A spray coating method is used as the coating method of the coating material. The spray gun to be used may be a commonly used air gun, preferably having a diameter of about 1.3 mmφ and an air pressure of 3 to 5 kgf / cm ² . The coating thickness at the time of coating is preferably 5 μm or more in order to obtain a surface of a molded article having sufficient scratch resistance and a good uneven pattern. Above 20 μm, the thermoplastic resin film stuck at a constant tension is partially applied. There is a possibility that it will be dissolved or the wall thickness will be extremely thin, and even if good surface irregularities are obtained in appearance and good scratch resistance is obtained, the UV blocking resistance is impaired and the outdoors. Or if you use it near the window where the sunlight directly hits indoors,
May locally turn yellowish brown. Therefore, it is desirable that the coating thickness is 15 μm or less, which gives sufficient scratch resistance and gives an embossed pattern to the thermoplastic resin film which is heat-fused with a constant tension so as not to impair the original weather resistance.

When spray coating, it is necessary to adjust the viscosity in order to form a uniform coating film with a coating material mainly composed of the above-mentioned crosslinkable compound, but as a general organic solvent, butanol, 2-propanol and the like are used. Alcoholic,
Organic solvents such as ketone-based compounds such as ethyl methyl ketone and ethyl butyl ketone and aromatic-based compounds such as toluene and xylene are used, and together with these various organic solvents, ester-based compounds such as butyl acetate and 1-propyl acetate. At least one of them is used, and the total content is 10 parts with respect to 100 parts by weight of the solid content of the coating composition mainly composed of the crosslinkable compound.
It is preferable that they are mixed in an amount of not less than 20 parts by weight, preferably not less than 20 parts by weight and not more than 40 parts by weight.

These ester compounds dissolve not only the viscosity of the coating composition but also the ultraviolet absorber, photoinitiator, etc. added for the purpose of imparting weather resistance to the coating film itself composed of the crosslinkable compound. It is not only necessary from the point of view, but it also means that it causes appropriate melting and swelling to the transparent thermoplastic resin film heat-sealed under a constant tension, and partially relaxes the tension to generate an embossed pattern. Is extremely effective at. If the content of the ester compound is less than 10 parts by weight, the additive such as the ultraviolet absorber may be precipitated, and if it exceeds 40 parts by weight, the crosslinking compound is cured by heating or irradiation with ionizing radiation. The drying step becomes longer and the productivity is impaired, and the transparent thermoplastic resin film is partially dissolved to expose the base material, which may impair the weather resistance of the molded article. For these reasons, the content of the ester organic solvent is preferably 10 parts by weight or more and 40 parts by weight or less.

As the ionizing radiation, ultraviolet rays or electron beams are typical. In the case of electron beam, 50-1000 keV, preferably 100, emitted from various electron beam accelerators such as Cockloft-Walton type, Bande-Cluff type, resonance transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type. An electron beam with an energy in the range of ~ 300 keV is used. In the case of ultraviolet rays, those emitted from an ultraviolet ray source using a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, and a metal halide lamp are used.

The surface irregularities forming the embossed pattern according to the present manufacturing method can have a roughness difference Rmax (measured according to JIS-B0601) of 1 to 40 μm, but in terms of appearance and of the transparent thermoplastic resin film. From the viewpoint of maintaining the required thickness, it is preferably 5 to 20 μm. Further, by providing the same or different embossed patterns on both sides, the visibility can be further suppressed, and a more suitable daylighting material can be obtained from the viewpoint of privacy protection. A cross-sectional view of a scratch-resistant translucent molded article having an embossed pattern produced by the method of the present invention is shown in FIG.

According to the present invention, it is not necessary to use various additives as a matting agent, and to eliminate the need for a step of mechanically forming irregularities on the surface using an embossing roll or the like, and providing an embossed pattern in advance. It is possible to form a surface having an embossed pattern by a simple process of spray coating a paint without injecting a material into a mold and transferring the embossed pattern to the surface.

Further, regarding the easiness of stains, which was a drawback of the molded product having an embossed pattern, since the surface is covered with the crosslinkable coating film, it is difficult for stains to occur, and even if it is adhered once, water, detergent, brush, etc. Can be easily wiped off with. In addition, if a thermoplastic resin film that forms an embossed pattern contains an ultraviolet absorber, it is possible to block ultraviolet rays and improve the light resistance of a material that originally lacks weather resistance, such as polycarbonate. , It can be used outdoors or in a place near windows where it is exposed to relatively sunlight without discoloring to yellowish brown.

[0032]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. (Example 1) Under the conditions of a temperature of 80 ° C. and a tension of 5 kgf / m,
An organic solvent-based paint (resin viscosity (resin viscosity (resin viscosity (resin viscosity The viscosity of the paint applied by spraying: 15 mPa · sec) was uniformly applied to a thickness of about 10 μm by the spray coating method.
After drying at 0 ° C. for 10 minutes, the coating material was cross-linked using an 80 w / cm (output per unit length, the same applies below) ultraviolet ray lamp, and a translucent material having a good embossed pattern was obtained. .

When the unevenness of the embossed pattern was measured by the stylus type roughness measuring method (JISB601) for the molded body based on this Example 1, Rmax = 25 μm, and the measurement result of the 60 degree specular gloss measurement method (JIS K7105). Is 65%,
The parallel light transmittance (JIS K7105) measurement result is 7
It was 5%.

(Comparative Example 1) When the coating material of Example 1 was applied directly to a glass having a thickness of 3 mm and cured, a glossiness was obtained.
The parallel light transmittance and the roughness Rmax are 130% and 9 respectively.
At 2% and 0.3 μm, an extremely smooth coating film surface was formed, and the original surface of the substrate was glaring and visibility could not be suppressed.

Example 2 Temperature 120 ° C., Tension 15 kgf
Under a condition of / m, a 50 μm thick acrylic resin film is attached to a 5 mm thick polycarbonate sheet, and 20 parts by weight of an ester compound is contained on the surface of 100 parts by weight of a solid content of an ultraviolet crosslinking compound. The organic solvent-based coating material (resin viscosity (viscosity of coating material applied by spraying): 15 mPa · sec) was uniformly applied to a thickness of about 10 μm by a spray coating method. 60 ° C, 1
After drying for 0 minutes, the paint was crosslinked using an 80 w / cm ultraviolet lamp, and a translucent material having a good embossed pattern was obtained.

The gloss, parallel light transmittance and Rmax of the molded product according to Example 2 were 60%, 73% and 30 respectively.
Even if it was rubbed with Steel Wool # 0000, no scratch was found and good scratch resistance was obtained.

(Comparative Example 2) When the coating material of Example 2 was directly applied to a polycarbonate sheet having a thickness of 5 mm and cured, the gloss, parallel light transmittance and Rmax were each 1
At 60%, 87% and 0.5 μm, an extremely smooth coating film surface was obtained, and the original surface of the base material could not be suppressed in glare and visibility.

(Comparative Example 3) For a composite sheet obtained by heat-sealing a thermoplastic resin film under the same conditions as in Example 2, 50 parts by weight of an ester compound was added to 100 parts by weight of a solid content of an ultraviolet-crosslinking compound. Spray paint the contained paint,
The coating film was cross-linked by UV energy. The gloss, parallel light transmittance, and Rmax of this molded body are 55 each.
%, 70%, and 40 μm, a good embossed pattern was obtained in appearance, but it was found by cross-sectional observation with a microscope that the thermoplastic resin film disappeared and the polycarbonate as a base material was partially exposed. . Further, when an accelerated weather resistance test was conducted using a sunshine weather meter, in Comparative Example 3, the polycarbonate of the base material turned yellow in a portion which was considered not to be covered with the thermoplastic resin in less than 600 hours of irradiation. Was observed. Regarding Example 2, even after irradiation for 1000 hours or longer, nothing was observed.

The results are shown in Table 1.

[Table 1]

[0040]

EFFECTS OF THE INVENTION According to the method of the present invention, a step which is troublesome for the base material itself, such as putting an additive in the base material, making unevenness with an embossing roll, or casting with a mold having an embossed pattern. The organic thermoplastic transparent film was fused without undergoing the above, or simply by spray-painting a paint containing an organic or inorganic filler, without forming a film with poor weather resistance, scratch resistance, and chemical resistance. In the above, it can be molded into various desired shapes, and thereafter by simply spraying a paint having no filler, a molded product having an embossed pattern can be obtained, and the productivity is extremely good. Since the surface is covered with a crosslinkable coating film, it is hard to get stains and easy to wipe. When a thermoplastic resin film is blended with an ultraviolet absorber, the light resistance is improved even when the substrate is discolored like polycarbonate. As a whole, the transparency can be secured, the surface glare can be suppressed, the visibility can be suppressed, and the privacy can be protected. Since it has good scratch resistance and chemical resistance, it will not be scratched or exposed to chemicals.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of an embossed pattern translucent plate manufactured by the method of the present invention.

[Explanation of symbols]

 1 Transparent substrate 2 Transparent thermoplastic resin film 3 Coating film of organic solvent paint containing crosslinkable compound

Claims (7)

[Claims] 1. A laminated composite in which a transparent thermoplastic resin film is heat-sealed on at least one surface of a translucent sheet is spray-coated with an organic solvent paint containing a crosslinkable compound, and the surface is uneven. A method for producing a scratch-resistant translucent molded article having an embossed pattern on its surface, characterized in that the organic solvent coating composition is cured. 2. The transparent sheet is a thermoplastic resin, and after the transparent thermoplastic resin film is heat-sealed, the transparent sheet is molded into an arbitrary shape, and the molded product is sprayed with an organic solvent paint containing a crosslinkable compound. The method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to claim 1, which is coated. 3. The method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to claim 1, wherein the translucent sheet is a polycarbonate resin. 4. The scratch resistance having an embossed pattern on the surface according to claim 1, wherein the tension when heat-sealing the transparent thermoplastic resin film is in the range of 5 to 15 kgf / m. Of producing a transparent light-transmissive molded article. 5. The scratch-resistant, transparent light-transmitting film having an embossed pattern on the surface according to claim 1, wherein the transparent thermoplastic resin film is an acrylic resin film containing an ultraviolet absorber. For producing flexible molded articles. 6. An organic solvent paint containing a crosslinkable compound, which has an ionizing radiation crosslinkable curable compound as a main component, has an embossed pattern on the surface of any one of claims 1, 2, 3, 4, and 5. A method for producing a scratch-resistant translucent molded article. 7. An organic solvent paint containing a crosslinkable compound, wherein 10 parts by weight or more and 40 parts by weight or less of an ester compound is added to 100 parts by weight of the crosslinking compound. 4. A method for producing a scratch-resistant translucent molded article having an embossed pattern on the surface according to any one of 4, 5, and 6.