JPH10249981A - Plastic molding formed with protective film and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plastic molding formed with a protective film easily removable with excellent protective properties on a plastic surface at the time of transporting or processing. SOLUTION: The plastic molding comprises (a) a uniform and releasable adhesive resin coated film as a protective film, and (b) non-adhesive resin film formed in this order on a surface. This molding has about 10 to 200g/25mm and 1,000 to 2,000g/25mm of releasing strength P1 at 0.3m/min of releasing speed of the protective film and releasing strength P2 at 30m/min of releasing speed according to JIS Z 0237 testing method. The adhesive resin includes acrylic resin, and the non-adhesive resin includes vinyl resin. The protective film may be transparent. This molding is obtained by forming the adhesive resin coated film by coating its surface with the adhesive resin and then forming the non-adhesive resin film by a coating method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic molded article having a protective film formed on its surface, and more particularly, to a plastic molded article having a protective film formed thereon which can prevent damage to the plastic surface during transportation and processing. About goods.

[0002]

2. Description of the Related Art When a plastic molded product is transported or processed, the surface of the plastic is easily damaged by an external force. For example, for plastic lenses,
Before the production of eyeglasses after lens production, transportation,
Through various processes such as cutting and assembling, the lens surface is easily damaged by friction and impact force during the process.

[0003] In order to prevent such damage, when a plastic molded product is transported, it is common to put a cushioning material softer than the plastic molded product around the plastic molded product, or to vacuum-pack it with a plastic film. However, this method is good for transportation, but has no protective effect when processing plastic.

[0004] Masking paint, which is usually used for metal products, has a protective effect at the time of transportation, but is easily peeled off by external force at the time of processing because of its weak adhesion. Further, since the masking paint is usually opaque, it is not suitable for plastic molded products such as dyed lenses and colored lenses, which need to be checked in a protected state.

Further, a method of improving the adhesion of the masking paint by modifying the surface of the plastic molded article by corona discharge or UV irradiation can be considered. However, it is difficult to control the adhesion, and it does not peel off during processing. In some cases, peeling cannot be performed when removing the protective film.

Japanese Patent Publication No. 57-20108 discloses that a masking seal having an adhesive applied to the back surface of a transparent film except for substantially the center thereof is attached to the surface of a prescription spectacle lens, so that a lens at the time of lens processing is formed. Methods for preventing surface damage are disclosed. However, it is technically extremely difficult to evenly attach a masking seal to a curved surface such as a lens, and the generation of wrinkles cannot be completely suppressed.
Dust may enter between the wrinkles and damage the lens surface.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a plastic molded article having a protective film which is excellent in protecting the plastic surface during transportation and processing and which can be easily removed, and a method for producing the same. Is to do.

Another object of the present invention is to provide a plastic molded product in which dust does not enter between the protective molded film and a protective film formed on the surface, and a method of manufacturing the same.

Still another object of the present invention is to provide a plastic molded article whose optical characteristics can be evaluated and confirmed even in a state of being covered with a protective film, and a method for producing the same.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that a plastic surface is coated with a coating liquid containing an adhesive resin to form an adhesive resin coating film. By forming a non-adhesive resin film, it has been found that a protective film that is resistant to external force and that can be easily peeled off can be formed uniformly, and the present invention has been completed.

That is, according to the present invention, (a) a uniform and peelable adhesive resin coating and (b) a non-adhesive resin coating are formed in this order on the surface of a molded article as a protective film. Provide plastic molded products. In this plastic molded product, the peel strength P1 at a peeling speed of 0.3 m / min and the peeling strength P2 at a peeling speed of 30 m / min according to JIS Z0237 test method are 10 to 20 respectively.
0g / 25mm and 1,000-2,000g / 25m
m. Further, the ratio P2 / P1 of the peel strengths P1 and P2 may be 5 to 200. The thickness of the adhesive resin coating is about 1 to 50 μm. The adhesive resin coating film is, for example, an acrylic adhesive (for example, an acrylic resin having a glass transition temperature of about 0 to −50 ° C.),
It can be composed of a rubber-based adhesive, a vinyl ether-based adhesive, a silicone adhesive or the like. The non-adhesive resin includes a resin soluble or dispersible in water or an organic solvent, for example, a vinyl resin. The protective film may have transparency. Plastic molded articles include plastic lenses and the like.

The present invention also relates to a method for producing a plastic molded article having a protective film formed on its surface, comprising coating an adhesive resin on the surface to form an adhesive resin coating film, Provided is a method for producing a plastic molded article on which a resin film is formed. The non-adhesive resin film,
For example, it can be formed by coating.

[0013]

Embodiments of the present invention will be described below in detail. [Plastic molded article] The plastic molded article is not particularly limited as long as it is a molded article made of plastic. Lenses such as spectacle lenses (for myopia, astigmatism, and hyperopia), sunglass lenses and other lenses, optical device parts, Examples include optical plastic molded articles such as optical disks; mechanical plastic molded articles such as mechanical parts and precision instrument parts; and electric / electronic plastic molded articles such as electric / electronic parts. Among these, optical plastic molded articles, particularly plastic lenses, are frequently used.

The type of plastic may be any resin that can be molded. For example, styrene resins (polystyrene,
Styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, etc., methacrylic resin (polymethyl methacrylate, etc.), olefin resin (polyethylene, polypropylene, etc.), fluororesin, polyamide, polyacetal, polycarbonate,
Thermoplastic resins such as saturated polyester, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, polyethersulfone, polyetheretherketone, polyamideimide, cellulose resin; phenolic resin, urea resin, melamine resin, unsaturated polyester, epoxy resin And the like.

[0015] The surface of the plastic molded article is imparted with, for example, hydrophilicity, oil resistance, moisture proofing, anti-fogging property, gas barrier property, antireflection property, and peeling property, and enhances hardness and adhesiveness of a tacky resin. Or various chemical treatments, coating treatments and the like.

[Adhesive Resin Coating Film] The adhesive resin coating film is formed to be uniform and peelable. The term “uniform” means that the entire surface of the molded article is covered with the coating film. As the adhesive resin constituting the adhesive resin coating film, a resin generally used as an adhesive can be used.
Such resins include, for example, acrylic adhesives (C _3-10 alkyl acrylates such as propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, etc.)
Or these and (meth) acrylic acid, methyl acrylate,
Ethyl acrylate, methacrylate, vinyl acetate, styrene, acrylonitrile, copolymers with acrylamides, etc., rubber-based adhesives (natural rubber, butyl rubber, polyisoprene, polyisobutylene, styrene-butadiene rubber, styrene-isoprene- Styrene rubber), vinyl acetate-based adhesives, vinyl ether-based adhesives (such as polyvinyl methyl ether, polyvinyl ethyl ether, and polyvinyl isobutyl ether), urethane-based adhesives, and silicone adhesives. These resins can be used alone or in combination of two or more.

Preferred adhesive resins include acrylic adhesives, rubber adhesives, vinyl ether adhesives, silicone adhesives and the like. More preferred pressure-sensitive adhesive resins include acrylic pressure-sensitive adhesives and rubber pressure-sensitive adhesives, particularly acrylic resins (acrylic copolymers) containing an acrylate (eg, C _3-10 alkyl acrylate) as a monomer component. ) Is included. The glass transition temperature of the acrylic resin is, for example, about 0 to −50 ° C., preferably −1
It is about 0 to -40 ° C.

Although the adhesive resin coating is not necessarily required to be transparent, the optical properties of the plastic molded article (for example,
When it is necessary to measure, evaluate, or confirm the power, color, and the like of the lens, it is preferable to have transparency.

The thickness of the adhesive resin coating film is within a range that can maintain the adhesion between the plastic molded product and the non-adhesive resin coating during transportation and processing, and does not impair the processability of the plastic product on which the protective film is formed. Although it can be appropriately selected, a range that can exhibit a buffering action against external impact is preferable. The thickness of the adhesive resin film is, for example, about 1 to 50 μm, preferably about 2 to 30 μm, and more preferably about 3 to 20 μm.

In the adhesive resin coating film, in addition to the above-mentioned adhesive resin, a tackifier (natural rosin, modified rosin, polyterpene resin, petroleum resin, aromatic petroleum resin, synthetic resin, etc.), viscosity modifier (paraffin) Additives such as a wax, a plasticizer, a filler, a softener, an antioxidant, an emulsion stabilizer, and an antifoaming agent.

[Non-adhesive Resin Coating] The non-adhesive resin constituting the non-adhesive resin coating may be any resin which does not exhibit adhesiveness by itself and has a film forming ability.

Non-tacky resins include, for example, olefin resins (polyethylene, ethylene-vinyl acetate copolymer,
Ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer, ionomer, polypropylene, propylene-
Ethylene copolymer, polybutylene, methylpentene resin, polybutadiene, etc., styrene resin (polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, etc.), vinyl ester resin (polyvinyl acetate, polybutyric acid) vinyl,
Vinyl chloride-vinyl acetate copolymer, etc.), polyvinyl alcohol resin (polyvinyl alcohol, ethylene-vinyl alcohol copolymer, etc.), polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), polyvinyl chloride, vinylidene chloride resin (vinylidene chloride) -Vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer, etc.), fluorine resin (polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride) Etc.), cellulosic resins (cellulose acetate,
Cellulose acetate propionate, cellulose acetate butyrate, cellulose nitrate, etc.), polycarbonate, polyester (polyethylene terephthalate,
Polybutylene terephthalate, etc.), polyamide (polyamide-6, polyamide-11, polyamide-12, polyamide-66, polyamide-610, etc.) and the like. These resins can be used alone or in combination.

Among these, resins having solubility or dispersibility (especially soluble) in water or an organic solvent (especially organic solvent) are preferable because a coating can be easily and uniformly formed by coating. Preferred non-adhesive resins include, for example, vinyl resins such as vinyl ester resins, polyvinyl alcohol resins, polyvinyl acetal, polyvinyl chloride, and vinylidene chloride resins. More preferred non-adhesive resins include vinyl ester resins such as polyvinyl acetate, polyvinyl alcohol resins such as polyvinyl alcohol, and polyvinyl acetal such as polyvinyl butyral.

The non-adhesive resin film does not necessarily have to be transparent, but the optical characteristics (for example, lens power, color, etc.) of the plastic molded product are measured, evaluated, and confirmed with the protective film applied. If necessary, it is preferably transparent. The non-adhesive resin film may contain additives such as a plasticizer, a filler, a softener, an antioxidant, an emulsion stabilizer and an antifoaming agent, in addition to the non-adhesive resin.

The thickness of the non-adhesive resin coating may be within a range that does not impair the workability of the plastic molded product, and is, for example, about 5 to 60 μm, preferably about 10 to 50 μm, and more preferably about 15 to 40 μm. The total thickness of the protective film composed of the adhesive resin coating and the non-adhesive resin coating is, for example, about 6 to 100 μm, preferably about 15 to 60 μm, and more preferably about 20 to 50 μm.

The plastic molded article of the present invention has
Since the non-adhesive resin coating is formed via the uniform and peelable adhesive resin coating, it has high resistance to impact force applied at high speed during transportation and processing, and it will be ready for commercialization. The feature is that the surface of the molded article can be protected from damage, but the protection film can be easily peeled off when the protection is no longer necessary. In addition, since the adhesive resin coating film is formed on the surface, even a plastic molded product having a curved surface such as an eyeglass lens has excellent adhesion of the protective film,
It is possible to prevent dust from entering between the molded article and the protective film and damaging the molded article surface. In addition, when the protective film has transparency, measurement of the optical characteristics with the protective film applied,
Evaluation, confirmation, etc. can be performed.

In a preferred plastic molded product, JIS
Peeling speed of protective film 0.3 m according to Z0237 test method
/ Min and the peel strength P2 at a peel speed of 30 m / min are about 10 to 200 g / 25 mm (preferably 20 to 150 g / 25 mm, particularly 50 to 9 g / 25 mm).
0 g / 25 mm), and 1,000 to 2,000 g / 2
About 5 mm (preferably 1,500 to 2,000 g / 2
5 mm, especially 1,800 to 2,000 g / 25 mm). Also, the ratio P2 / P1 of the peel strengths P1 and P2
Is, for example, about 5 to 200, preferably about 10 to 100, and more preferably about 20 to 40. The peel strength is
It can be adjusted mainly by appropriately selecting the resin constituting the adhesive resin coating film.

[Production of Plastic Molded Product with Protective Film Formed] The plastic molded product with the protective film formed thereon is coated with a coating solution containing an adhesive resin, and dried and adhered if necessary. It can be manufactured through a first step of forming an adhesive resin coating and a second step of forming a non-adhesive resin coating on the surface of the adhesive resin coating.

In the first step, as a coating method, a conventional method such as a dipping method, a coating method using a brush or the like, a spray method, a coating method using a coater such as a roll coater, a bar coater, and a knife coater can be used. . In the case of a plastic molded product having a curved surface such as a lens, it is preferable to perform the coating by a dipping method, a spraying method, or the like in order to coat uniformly.

The liquid of the coating liquid can be appropriately selected from a solution, an emulsion, and a melt depending on the type of the resin of the plastic molded article and the type of the resin to be coated. The coating liquid may include water or an organic solvent as a solvent, the additive, and the like, depending on the liquid state and type of the coating liquid, in addition to the adhesive resin. When a solution or an emulsion coating solution is used, the solid content of the coating solution is, for example, 5%.
It is about 70 to 70% by weight, preferably about 10 to 50% by weight, and more preferably about 15 to 40% by weight.

Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane and 1,2-dichloroethane; methanol, ethanol, 1- Propanol, 2-propanol, 1-
Alcohols such as butanol and 2-butanol; esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, cellosolve acetate and ethyl propionate; ethers such as diethyl ether, dibutyl ether, dioxane and tetrahydrofuran; acetone , Methyl ethyl ketone, ketones such as cyclohexanone; acetonitrile, N-methylpyrrolidone, N,
An aprotic polar solvent such as N-dimethylformamide and dimethyl sulfoxide can be exemplified.

In the case of coating by dipping, the speed of pulling up the plastic molded article immersed in the coating solution can be appropriately selected within a range that does not impair the uniformity of the coating, and is, for example, 5 to 200 mm / min, preferably 10 to 200 mm / min.
It is about 100 mm / min, more preferably about 20 to 60 mm / min. The drying temperature of the coating film varies depending on the type of the resin and the solvent to be used, but is usually about 20 to 150 ° C, preferably about 30 to 100 ° C, and more preferably about 40 to 80 ° C.

The second step can be carried out by a conventional film forming method such as a coating method and a laminating method. Even in the case of a plastic molded product having a curved surface, wrinkling can be prevented and the protective film can be formed uniformly. It is preferably carried out by a coating method capable of improving the properties and adhesion. The coating can be performed in the same manner as in the first step.

The present invention can be applied to a wide range of plastic molded products for optical, mechanical, electric and electronic applications, and is particularly useful for molded products having curved surfaces such as lenses. Further, a plastic molded product having a transparent protective film is suitable for a half-stained lens, a prescription lens, and the like.

[0035]

According to the plastic molded article and the method for producing the same of the present invention, the protective property of the plastic surface during transportation and processing is excellent, and the protective film can be easily removed. Further, even if the plastic molded article has a curved surface, the protective film has excellent adhesion, so that it is possible to prevent dust from entering the protective film and causing damage. Further, when the protective film has transparency, the optical characteristics can be evaluated and confirmed even in a state where the protective film is covered with the protective film.

[0036]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 An acrylic copolymer solution (Vinylol AV6660; manufactured by Showa Polymer Co., Ltd.) as an adhesive resin was diluted with ethyl acetate to a solid content of 20% by weight, and the first coating was performed. A liquid was prepared. Also, a methanol solution of vinyl acetate resin [Sebian A800; manufactured by Daicel Chemical Industries, Ltd.]
Was diluted with methanol to a solid content of 25% by weight to prepare a second coating solution.

A plastic lens (biconvex lens; made of polycarbonate resin) having a hard-coated surface was immersed in the first coating solution, pulled up at a speed of 40 mm / min, and dried at 60 ° C. for 15 minutes. Next, the above lens is immersed in the second coating liquid, and the speed is 40 mm /
And dried at 60 ° C. for 30 minutes. The total thickness of the protective film formed on the lens surface was 33 μm. Among them, the thickness of the adhesive resin coating film was about 15 μm. The peel strength of the protective film at a peel speed of 0.3 m / min according to JIS Z0237 test method was 70 g / 25 mm, and the peel strength at a peel speed of 30 m / min was 1,500 g / min.
It was 25 mm.

With respect to the thus obtained lens having a protective film formed on its surface, according to a conventional lens processing step,
The outer shape was cut, the cut surface was buffed, ultrasonic water washes, holes were drilled, and parts were assembled. When the protective film was peeled off and the lens surface was observed, the lens surface was well finished without any scratches. Also, there was no damage to the protective film after the lens processing.

Comparative Example 1 A commercially available urethane resin paint (Strip Clear KS-
5; manufactured by Kitakawa Products; solid content: 25% by weight; solvent: ethyl acetate, isopropyl alcohol), the same plastic lens as in Example 1 was immersed, pulled up at a speed of 40 mm / min, and dried at 60 ° C. for 15 minutes. . The surface of the lens was completely covered with a protective film. Protective film thickness is 15 ~ 19μ
m. When this lens was processed in the same manner as in Example 1, the protective film was peeled off in the outer shape cutting step which was the first step.

Comparative Example 2 The same plastic lens as in Example 1 was immersed in a commercially available vinyl resin paint (Chemipak L-03; manufactured by Sansai Kokusai; solid content: 30% by weight; solvent: toluene), and the speed was 40 m.
It was pulled up at m / min and dried at 60 ° C. for 15 minutes. The surface of the lens was completely covered with a protective film. The thickness of the protective film was 24-34 μm.

When this lens was processed in the same manner as in Example 1, the protective film was peeled off in the outer shape cutting step which was the first step.

Claims (12)

[Claims] 1. A plastic molded article having a protective film (a) a uniform and peelable adhesive resin coating and (b) a non-adhesive resin coating formed in this order on the surface of the molded article. 2. The peel strength P1 at a peel speed of 0.3 m / min and the peel strength P2 at a peel speed of 30 m / min according to JIS Z0237 test method are 10 to 20 respectively.
0g / 25mm and 1,000-2,000g / 25m
The plastic molded product according to claim 1, wherein m is m. 3. The ratio P2 / P1 of the peel strength P1 at a peeling rate of 0.3 m / min to the peeling strength P2 at a peeling rate of 30 m / min according to JIS Z0237 test method is 5 to 2.
The plastic molded article according to claim 1, wherein the number is 00. 4. The plastic molded article according to claim 1, wherein the thickness of the adhesive resin coating film is 1 to 50 μm. 5. The adhesive resin coating film is an acrylic adhesive,
The plastic molded article according to claim 1, comprising at least one kind of adhesive selected from a rubber-based adhesive, a vinyl ether-based adhesive, and a silicone adhesive. 6. The adhesive resin coating film has a glass transition temperature of 0 to-.
The plastic molded article according to claim 5, which is made of an acrylic resin at 50 ° C. 7. The plastic molded article according to claim 1, wherein the non-adhesive resin film is made of a resin soluble or dispersible in water or an organic solvent. 8. The plastic molded article according to claim 7, wherein the non-adhesive resin film is made of a vinyl resin. 9. The plastic molded article according to claim 1, wherein the protective film has transparency. 10. The plastic molded article according to claim 1, wherein the plastic molded article is a plastic lens. 11. A method for producing a plastic molded article having a protective film formed on its surface, comprising coating an adhesive resin on the surface to form an adhesive resin film, and then forming a non-adhesive resin film. Of manufacturing plastic molded products. 12. The method according to claim 11, wherein the non-adhesive resin film is formed by coating.