JPH0542970B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a surface-treated plastic molded article with excellent scratch resistance, surface smoothness, adhesion, and light transmittance. (Prior art) Plastic products molded from transparent plastics such as polymethyl methacrylate and polycarbonate are popular in fields where glass products have traditionally been used due to their transparency, impact resistance, good moldability, and low cost. Because of its various advantages, it has come to be used in large quantities as an alternative to glass products, such as optical disks, lenses, plates, and molded products. Optical discs, typically represented by digital audio discs, are made of polymethyl methacrylate resin discs or polycarbonate resin discs on which signals are written by injection molding or photopolymer, and a metal such as silver or aluminum is coated on the signal side. It is manufactured by forming a thin film using methods such as sputtering and vapor deposition.
However, plastics such as polymethyl methacrylate and polycarbonate have low surface hardness and low resistance to abrasion, so their surfaces can be damaged by contact with other objects, scratches, collisions, etc., resulting in a loss of aesthetic appearance. At the same time, optical properties were lost, resulting in a fatal drawback that significantly reduced commercial value. In order to improve these drawbacks, various surface treatment methods have been proposed to increase the surface hardness of plastics and provide them with wear resistance. (Problems to be Solved by the Invention) However, thermosetting surface treatments have drawbacks such as deformation of the disk and decreased productivity because curing requires a high temperature and a long time. Also,
Ultraviolet curing type surface treatment has drawbacks such as deterioration of optical properties such as adhesion, planar smoothness, and light transmittance, and is therefore rarely carried out in general. Regarding ultraviolet curable surface treatment, a method using a composition mainly consisting of a polyfunctional monomer having three or more (meth)acryloyloxy groups in the molecule, a photopolymerization initiator, and a fluorine-based surfactant (Japanese Patent Laid-Open No. 1989-1999) -83477), per 1000 units of molecular weight
A cross-linked curable coating composition based on a cross-linked polymerizable compound having 0.5 to 12 (meth)acryloyloxy groups and a fluorine-based surfactant (Japanese Patent Application Laid-Open No. 1989-1999)
No. 83425) etc. have been proposed, but scratch resistance,
Adhesion, surface smoothness, etc. deteriorate, and a satisfactory result cannot be obtained. Under these circumstances, there has been a strong demand from the industry for the development of a surface treatment method that satisfies adhesion, surface smoothness, light transmittance, and scratch resistance. An object of the present invention is to provide a plastic molded product, such as an optical disc, which has excellent scratch resistance, surface smoothness, adhesion, light transmittance, and stain resistance. (Means for Solving the Problems) As a result of intensive research to solve the drawbacks of conventional plastic molded products, especially the surface treatment of optical disks, the present inventors have developed a plastic molded product (1).
Epoxy acrylate resin having two or more acryloyl groups and/or methacryloyl groups in the molecule, (2) photopolymerizable monomer having three or more acryloyl groups or/and methacryloyl groups in the molecule, (3) light It has been discovered that the above-described drawbacks of surface treatment of optical disks can be solved by surface treatment using an ultraviolet curable surface treatment agent containing an initiator and (4) a fluorine-based surfactant, and the present invention has finally been achieved. reached. Further, the present inventors have discovered that the surface treatment agent of the present invention exhibits similar effects not only on optical disks but also on formed products having other shapes, and have arrived at the present invention. That is, the present invention provides plastic molded products (1)
Epoxy acrylate resin having two or more acryloyl groups and/or methacryloyl groups in the molecule, (2) photopolymerizable monomer having three or more acryloyl groups or/and methacryloyl groups in the molecule, (3) light This is a surface-treated plastic molded product characterized by being surface-treated using an ultraviolet curable surface treatment agent containing an initiator and (4) a fluorine-based surfactant. The surface-treated plastic molded article of the present invention not only has excellent transparency and gloss, but also has excellent scratch resistance, surface smoothness, adhesion, and light transmittance. Examples of the plastic molded article of the present invention include molded articles made of polymethyl methacrylate, polycarbonate, epoxy resin, cellulose plastic, polyvinyl chloride, and the like. Particularly useful are transparent plastic moldings. Forms of plastic molded products include sheets, films, disks, lenses, frames, etc.
The manufacturing method of the molded product is not particularly limited, such as extrusion molding or injection molding. (1) Epoxy acrylate resin having two or more acryloyl groups and/or methacryloyl groups in the molecule used in the present invention is a (meth)acrylate compound of an epoxy compound having two or more epoxy groups in one molecule ( It represents a methacrylate compound and an acrylate compound (hereinafter similarly abbreviated), and the epoxy equivalent of the epoxy compound that is the starting material is 100 to 4000, preferably 100 to 1000. Typical photopolymerizable epoxy (meth)acrylate resins include (i) (meth)acrylate compounds of polyglycidyl ethers of divalent or higher polyvalent phenols, such as bisphenol A, bisphenol F, and halogenated bisphenols; (ii) (meth)acrylate compounds of bisphenol type epoxy resins, which are diglycidyl ethers such as phenol A, and novolac type epoxy resins, which are polyglycidyl ethers such as phenol novolac and cresol novolac; (meth)acrylate compounds of polyglycidyl ethers of alcohols, such as ethylene glycol, propylene glycol, neopentyl glycol, 1,4
-butanediol, 1,6-hexanediol,
(meth)acrylate compounds of polyglycidyl ethers of divalent or higher aliphatic alcohols such as trimethylolpropane; (iii) divalent compounds such as phthalic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and adipic acid; (Meta) of polyglycidyl esters of the above polyhydric carboxylic acids
acrylate compounds, (iv) polyglycidyl ether (meth)acrylate compounds in which the active hydrogen bonded to the nitrogen atom of aniline, isocyanuric acid, etc. is replaced with a glycidyl group, (v) epoxidized olefin bond in the molecule. Obtained vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxy)
(meth)acrylate compounds of alicyclic polyepoxy compounds such as cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, (vi) N,N,N',N'-tetraglycidyl meta-xylene diamine, N,N,N',N'-tetraglycidyl-1,3-bis(aminomethyl)
Examples include (meth)acrylate compounds of aminopolyepoxy compounds such as cyclohexane. These epoxy acrylate resins may be used alone or in combination of two or more. Among these, preferred epoxy acrylate resins include diglycidyl ether of bisphenol A, phenol novolac type polyepoxy compounds, cresol novolac type polyepoxy compounds, and (meth)acrylate compounds of polyhydric alcohol polyepoxy compounds. can give. In addition, one epoxy group is added in the molecule of allyl glycidyl ether, phenyl glycidyl ether, etc.
It is also possible to use a (meth)acrylate compound of the epoxy compound in combination. (2) Photopolymerizable compounds having three or more acryloyl groups and/or methacryloyl groups in the molecule used in the present invention include (i) trimethylolpropane tri(meth)acrylate,
Poly(meth)acrylates of trivalent or higher aliphatic polyhydric alcohols such as trimethylolethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. poly(meth)acrylates of trivalent or higher halogen-substituted aliphatic polyhydric alcohols, tris(meth)acryloyloxyethyl isocyanurate, tris(meth)acryloyloxypropyl isocyanurate, tris(meth)acryloyloxybutyl isocyanurate There are tris(meth)acryloyl alkyl isocyanurates such as. These trifunctional or higher functional (meth)acrylate compounds may be used alone or in combination of two or more. Further, various other oligomers and polymers and (meth)acrylate monomers having less than two functional groups can be used in combination as necessary. Examples of the photoinitiator (3) that promotes the photopolymerization reaction of the ultraviolet curable resin of the present invention include ketals such as benzyl dimethyl ketal, benzoin methyl ether, benzoin ethyl ether, benzoin-1-propyl ether, benzoin, α−
Benzoins such as methylbenzoin, 9,10-
Anthraquinone, 1-chloroanthraquinone, 2
-Anthraquinones such as chloranthraquinone and 2-ethylanthraquinone, benzophenone,
Benzophenones such as p-chlorobenzophenone and p-dimethylaminobenzophenone, 2-hydroxy-2-methylpropiophenone, 1-
(4-isopropylphenyl)-2-hydroxy-
Propiophenones such as 2-methylpropiophenone, suberones such as dibenzosuberone, sulfur-containing compounds such as diphenyl disulfide, tetramethylthiuram disulfide, and thioxanthone, pigments such as methylene blue, eosin, and fluorescein. These photoinitiators may be used alone or in combination of two or more. The amount of photoinitiator added is 0.05 to 20% by weight, preferably 0.5 to 20% by weight based on the resin component of the ultraviolet curable resin.
It is 10% by weight. The fluorine-based surfactants used in the present invention include perfluorocarbonyl fluoride (C ₇ F ₁₅ COF) and perfluorosulfonyl fluoride (C ₈ F ₁₇ SO ₂ F) obtained by electrolytic fluorination. ), starting materials such as w-H-perfluoroalcohol (H(CH ₂ CF ₂ ) _o CH ₂ OH) obtained by telomerization of methanol and tetrafluoroethylene, and perfluoroiodide. and fluorine-based surfactants derived from perfluoroalkene monomers. especially

[Formula] (n is an integer, Rf represents a fluoroalkane) and [-(CH ₂ -CH ₂ -O]-

A fluorine-based surfactant which is a copolymer with [Formula] (m is an integer) is preferred. The amount of the fluorine surfactant added is 0.001 to 20% by weight, preferably 0.01 to 10% by weight. The surface treatment agent of the present invention can be diluted with a compatible organic solvent and used.
Examples of such diluents include alcohol-based, ether-based, ester-based, ketone-based, aromatic hydrocarbon-based, chlorinated hydrocarbon-based, and polyhydric alcohol derivative-based solvents. The diluent may be used alone or in combination of two or more. Furthermore, various additives such as an antistatic agent and an antifoaming agent may be added to the surface treatment agent of the present invention as required. In the present invention, before processing the plastic molded article, it is common to perform pretreatment such as blowing with a clean blow, solvent cleaning, ultrasonic cleaning with an aqueous surfactant solution or ion-exchanged water, and solvent vapor cleaning. The ultraviolet curable resin can be applied to the plastic molded article by a conventional method, such as a dipping method, a spray method, a spin coating method, a roll coating method, or a bar coating method. Particularly in the case of optical discs, spin coating is preferred. The thickness of the coating layer is 0.1 to 50 μm, preferably 0.5 to 50 μm.
It is desirable to apply the coating to a thickness of 30 μm. 1.0μm
If it is less than 50 μm, the scratch resistance and surface hardness will be insufficient, and if it exceeds 50 μm, cracks will easily occur in the coating, which is not preferable. In order to cure the applied ultraviolet curable resin of the present invention, a method of irradiating ultraviolet rays in the wavelength range of 200 to 450 nm is used. When the coating film is cured by ultraviolet irradiation, it is preferable to carry out the irradiation curing in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas. (Effects of the Invention) In the present invention, by surface treatment, it is possible to obtain a plastic molded article which not only has excellent light transmittance and surface smoothness, but also has excellent scratch resistance and adhesion. On the other hand, since it uses ultraviolet curing, it can be cured at low temperatures, so there is no deformation of the plastic molded product due to heat, and the curing time is greatly shortened.
It is possible to greatly improve productivity. (Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. The measurement method in the examples was as follows. Scratch resistance test: The degree of scratches was measured after rubbing 30 times with a load of 1 kg using #0000 steel wool. Adhesion test (JIS D 0202): 1mm on coated surface
Make 11 vertical and horizontal cuts at intervals (cross cuts), place cellophane tape on top of this, and then
The film was strongly peeled off in a 45° direction and the number of squares that did not peel off was measured. Surface hardness (JIS D 0202): Pencil (Mitsubishi UN1)
The coating was strongly pressed against the coated surface at an angle of 45° to cause scratches, and the presence or absence of scratches was measured. Light transmittance: Light transmittance in the wavelength range of 400 to 700 mm was measured using a double beam spectrophotometer (Hitachi). Surface smoothness (Ra): Surface roughness meter ("Tokyo Seimitsu")
The center line average roughness was measured using In Examples and Comparative Examples, parts represent parts by weight. Example 1 10 parts of Lipoxy SP-1509 (manufactured by Showa Kobunshi), which is a bisphenol A type epoxy acrylate resin, 40 parts of pentaerythritol tetraacrylate, 30 parts of methyl cellosolve, and 10 parts of toluene were placed on a transparent polycarbonate plate with a thickness of 1.5 mm. 10 parts of isopropyl alcohol, 1.5 parts of α-hydroxycyclohexyl phenyl ketone (initiator), and 0.5 parts of the fluorine-based surfactant Surflon S-381 (manufactured by Asahi Glass).
After drying at 40℃ for 5 minutes, apply an 80W/cm water-cooled high-pressure mercury lamp at a distance of 15cm under an inert gas atmosphere for 40 minutes.
It was irradiated for seconds and cured. The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: 2H Light transmittance: 90% Surface smoothness: 0.005 μm Example 2 Except for using a transparent polymethyl methacrylate plate instead of the transparent polycarbonate plate in Example 1. A transparent polymethyl methacrylate molded plate was surface-treated in the same manner as in Example 1. The measurement results of the surface-treated polymethyl methacrylate molded plate were as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: 8H Light transmittance: 94% Surface smoothness: 0.005 μm Example 3 Lipoxy SP4010, which is a phenol novolac type epoxy acrylate instead of
A polycarbonate plate was surface-treated in the same manner as in Example 1, except that polycarbonate (manufactured by Showa Kobunshi) was used.
The measurement results of the surface-treated polycarbonate plate are as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: 3H Light transmittance: 90% Surface smoothness: 0.008 μm Example 4 Except for using dipentaerythritol hexaacrylate instead of pentaerythritol tetraacrylate in Example 1 A polycarbonate plate was surface-treated in the same manner as in Example 1.
The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: 3H Light transmittance: 90% Surface smoothness: 0.008 μm Comparative example 1 Lipoxy SP, a bisphenol A type epoxy acrylate resin, was applied to a 1.5 mm thick transparent polycarbonate plate. 50 parts of -1509 (manufactured by Showa Kobunshi), 30 parts of methyl cellosolve, 10 parts of toluene, 10 parts of isopropyl alcohol, 1.5 parts of α-hydroxycyclohexyl phenyl ketone (initiator), and fluorine surfactant (previously 0.5 parts of ultraviolet curable resin was applied using a spinner, dried with hot air at 40℃ for 5 minutes, and then cured by irradiating it with an 80W/cm water-cooled high-pressure mercury lamp at a distance of 15cm in an inert gas atmosphere for 40 seconds. Ta.
The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: Scratch generation adhesion: 0/100 Surface hardness: 2H Light transmittance: 90% Surface smoothness: 0.02 μm Comparative example 2 50 parts of pentaerythritol tetraacrylate and 30 parts of methyl cellosolve on a 1.5 mm thick transparent polycarbonate plate 10 parts of toluene, 10 parts of isopropyl alcohol, 1.5 parts of α-hydroxycyclohexyl phenyl ketone (initiator), and 0.5 parts of fluorine-based surfactant (mentioned above) were applied with a spinner, and 40 parts of After drying for 5 minutes at °C.
The material was cured by irradiating it with an 80 W/cm water-cooled high-pressure mercury lamp at a distance of 15 cm for 40 seconds in an inert gas atmosphere. The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: 2H Light transmittance: 87% Surface smoothness: 0.05 μm Comparative example 3 Same as Example 1 except that fluorine-based surfactant was not added in Example 1. The polycarbonate plate was surface treated. The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: No damage Adhesion: 100/100 Surface hardness: H Light transmittance: 90% Surface smoothness: 0.1 μm Comparative example 4 Except for using neopentyl glycol diacrylate instead of pentaerythritol tetraacrylate in Example 1 A polycarbonate plate was surface-treated in the same manner as in Example 1. The measurement results of the surface-treated polycarbonate plate were as follows. Scratch resistance: Scratch occurrence adhesion: 100/100 Surface hardness: HB Light transmittance: 87% Surface smoothness: 0.05μm

Claims (1)

[Claims] 1 Plastic molded products are made of (1) epoxy acrylate resin having two or more acryloyl groups and/or methacryloyl groups in the molecule, (2) photopolymerizable resin having three or more acryloyl groups and/or methacryloyl groups in the molecule. 1. A surface-treated plastic molded article, characterized in that it is surface-treated using an ultraviolet curable surface treatment agent containing a compound, (3) a photoinitiator, and (4) a fluorine-based surfactant.