JP2006056955A - Colored plastic article and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a colored plastic product in which a plastic base is colored in a stable density and a coating film as a coloration medium is surely removed by washing with water and to provide a method for producing the same. <P>SOLUTION: A coating film consisting essentially of an anionic surfactant is formed on a plastic lens and ink is supplied to the surface of the coating film by an inkjet method. Then the lens is heated, the colorant is transferred to the lens side and the coating film is removed by washing in water to give the lens. Consequently, the plastic lens is colored in a stable density and the coating film is surely removed by washing with water. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a colored plastic article and a method for producing the same.

In recent years, plastic lenses as plastic articles have been used frequently in place of glass lenses because they can be easily molded and are not easily broken. In addition, the demand for so-called colored lenses that are colored from a medical and cosmetic viewpoint is increasing. However, plastic is more easily colored as a reason why plastic lenses are superior to glass lenses. Is mentioned.
The coloring method of the lens is 1) The method of directly immersing the lens in the dye solution, 2) The method of premixing the dye in the plastic substrate, 3) The colored film is stuck on the lens surface and the dye is lensed from the film. 4) There is a method of heating the dye in the gas phase and sublimating it by vapor deposition onto the lens, but none of them are sufficient in terms of stable color development without unevenness and coloring at a predetermined density. there were.
Therefore, a staining method as disclosed in Technical Document 1 has been developed. In Technical Document 1, a water-soluble polymer is coated on the surface of a plastic lens to form a film, and the lens in this state is immersed in the dye or applied to the surface of the film by means such as an ink jet method and then heated. The dye is diffused inside the plastic lens, and then the coating is washed with water and removed from the lens surface.
Japanese Patent No. 3075403

The water-soluble polymer used in the method of Technical Document 1 has a water-soluble functional group such as a hydroxyl group or an amino group. As a result, water solubility is to be expressed. However, on the other hand, these functional groups are also groups that generally contribute to adhesiveness. Therefore, the water-soluble polymer is firmly adhered to the lens surface in the water-washing step of the water-soluble polymer in the above-mentioned technical document 1, and does not necessarily peel off cleanly. There was a thing. The water-soluble polymer is a polymer polycondensate, and the molecular weight is not necessarily constant. Therefore, the film quality of the coating made of a water-soluble polymer is difficult to be constant, and this may cause uneven dyeing.
The present invention has been made in order to solve the above-mentioned problems, and its purpose is to color a plastic base material with a stable concentration and a colored plastic article that can reliably remove the coating as a coloring medium by washing with water. It is to provide a manufacturing method.

In order to achieve the above object, in the invention described in claim 1, a film mainly composed of a surfactant is formed on a plastic substrate, and a coloring solution containing a colorant as a component is supplied to the surface of the film. The gist is that the colorant is transferred to the plastic base material through the coating film after heating to obtain the coating film by washing with water.
Further, in the invention according to claim 2, in the invention according to claim 1, an anionic surfactant, a nonionic surfactant and a cationic surfactant are used as the surfactant as a film component formed on the plastic substrate. The gist is that at least one selected from surfactants is used.
The gist of the invention of claim 3 is that, in the invention of claim 1 or 2, the main component is an anionic surfactant as a surfactant to be a film component formed on a plastic substrate. And
The gist of the invention according to claim 4 is that, in the invention according to any one of claims 1 to 3, the blending ratio of the surfactant in the film is 50% by weight or more.
The gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4, colloidal particles are added as a film component used in combination with the surfactant.
The gist of the invention according to claim 6 is that, in the invention according to any one of claims 1 to 5, a water-soluble polymer is added as a film component used in combination with the surfactant.
The gist of the invention according to claim 7 is that, in the invention according to any one of claims 1 to 6, an acrylic emulsion is added as a film component used in combination with the surfactant.
In the invention according to claim 8, a film forming step of forming a film mainly composed of a surfactant on a plastic substrate, and a color containing a colorant as a component on the surface of the film formed in the film forming step In the coloring solution supply step for supplying the solution, and in the coloring solution supply step, the same colorant that has penetrated into the coating is transferred to the plastic substrate through the coating to be colored. The gist of the present invention is to have a coloring step and a water washing and removing step of washing and removing the same film on the lens surface after the plastic substrate is colored in the coloring step.

Examples of the plastic substrate used in the present invention include polymethyl methacrylate and its copolymer, polycarbonate, polydiethylene glycol bisallyl carbonate (CR-39), cellulose acetate, polyethylene terephthalate, polyvinyl chloride, polyurethane resin, polythiol. Examples include urethane and other sulfur-containing resins. These can be selected depending on the colorability and physical properties (lightness, impact resistance, scratch resistance, etc.) according to the application. A typical example of the use of a plastic substrate is a colored plastic lens. Examples of the colored plastic lens include eyeglass lenses, contact lenses, camera lenses, telescope lenses, and magnifier lenses.
The surfactant is not particularly limited as long as it has solubility in an aqueous medium and does not react with the colorant or does not easily react. In particular, anionic, nonionic and cationic surfactants are preferred, and anionic surfactants are most preferred. Therefore, it is most preferable that the surfactant is mainly an anionic surfactant.
Examples of such anionic surfactants include alkylbenzene sulfonate (Perlex SSL, which will be described later), alkyl sulfate ester salt (Emar 2F-30, which will be described later), sulfate ester salt of polyoxyethylated higher alcohol (Sandet END, which will be described later). ), Higher alkyl sulfonates, α-olefin sulfonates, higher fatty acid ester sulfonates, higher alcohol sulfate esters, higher fatty acid ester sulfate esters, phosphate ester salts, fatty acid soaps, and other anionic surfactants Agents and the like.
Examples of nonionic surfactants include polyoxyethylene alkyl and alkylaryl ether type nonionic surfactants and ether ester type nonionic surfactants.
Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, and alkyl quaternary ammonium salts.
Surfactants may be used alone or in combination of two or more. The blending ratio of the surfactant in the coating component is preferably 50% by weight or more even when other additive components are taken into consideration.
In addition to the surfactant, colloidal particles are preferably added to the coating component. A colloidal particle is a particle having a predetermined particle size that exhibits colloidal characteristics, and examples thereof include colloidal silica. It is considered that the colloidal particles become an obstacle that inhibits the passage of the colorant in the coating and contribute to the diffusion of the colorant.
Furthermore, it is preferable to add a water-soluble polymer to the coating component. Examples of the water-soluble polymer include polyvinyl alcohol, polyacrylic acid, polyacrylic acid metal salt, polyacrylamide, polyvinyl pyrrolidone, polyethylene glycol and the like. The water-soluble polymer may be used alone or in combination of two or more.
Further, an acrylic emulsion may be added to the coating component. It is considered that when the acrylic emulsion is added to the film component, the film forming ability is improved, and the film is hardly dissolved when the colored solution is supplied to the surface of the film. More preferably, the acrylic emulsion has a glass transition temperature (Tg) of about −20 to 10 ° C.

In the production of colored plastics, first, a film containing a surfactant as a main component is formed on the surface of a plastic base material to be colored. The method of forming the coating is not particularly limited, but generally, a coating solution prepared by dissolving a coating component such as a surfactant in an aqueous medium is coated on a plastic substrate as uniformly as possible, and the coating is dried. It is advantageous to encourage As an aqueous medium, water is used as a main component, but an organic solvent having miscibility with water can be appropriately added and used as long as the object of the present invention is not impaired. Any conventionally known means can be used as the coating means as long as the coating is as uniform as possible. For example, brush coating, spin coating, dipping, spraying, or the like can be used. In particular, it is preferable to use a film forming apparatus such as a spin coater in terms of uniformity. It is necessary to quickly vaporize the solvent, that is, to dry the formed film. Drying may be natural drying or forced drying.
A colored solution containing a colorant as a component is supplied to the dried coating surface. As a result, the colored solution penetrates the coating. In other words, compared with the case where the coloring solution is supplied directly to the plastic substrate, the solution is not repelled or stays only on a part of the surface of the substrate, and the colorant is evenly distributed over the entire film as a part of the coloring solution. Will be supplied. In the present invention, since the coating is mainly composed of a surfactant, the colored solution permeates extremely uniformly and uniformly compared to a coating mainly composed of a water-soluble polymer. At this time, the presence of colloidal particles as described above enables the colored solution to diffuse more uniformly within the coating. The colorant used in the present invention is generally a dye which is sparingly soluble in water and has a sublimation property which is used as a suspension dispersed in water.

The method for supplying the coloring solution to the coating surface is not particularly limited as long as the coloring agent can be supplied uniformly to the coating surface without unevenness. Conventionally known methods such as brushing, spin coating, dipping, spraying, and ink jet methods can be used. In particular, an application method by an ink jet method is preferable from the viewpoint of efficient use of a colorant (ink) and the ability to supply ink with a desired color tone and density using a computer.
In this way, the plastic base material in which the colorant has penetrated into the coating film is subjected to heat treatment, and the colorant in the dyeing liquid is sublimated and transferred to the plastic base material side. In general, when the heating temperature is high and the heating time is long, the coloring density becomes high or the plastic substrate is deformed. Therefore, it is desirable to select the optimum values for the heating temperature and the heating time. It is also possible to reduce the pressure during heating. It is considered that the colorant supplied can be more finely diffused by reducing the pressure. The heating means is not particularly limited as long as it can uniformly heat the plastic substrate, and for example, an electric oven, an infrared oven, a hot air circulation oven, or the like can be used. It is also possible to use a vacuum oven that serves both as an oven and a decompression means.
After the heating is completed, a cleaning process is performed to remove the film remaining on the surface of the plastic substrate. In the present invention, the surfactant as the main component of the coating is considered to be easily removed because it has a relatively low molecular weight and is easily dissolved in water, and in particular, the hydrophobic group does not participate in adhesion. An ultrasonic cleaner can be used for cleaning.

  According to the inventions described in the above claims, it is possible to color the plastic substrate at a stable concentration by coloring the film mainly composed of a surfactant as a medium, and to ensure that the film is washed with water. It can be removed.

Example 1
(1) Application of surfactant to lens The operation program of a spin coater (Mikasa Co., Ltd.) is Step 1: SLOPE 3 sec, Step 2: 1400 rpm × 15 sec, Step 3: SLOPE 5 sec, a urethane system having a refractive index of 1.6 and an Abbe number of 42 A lens (frequency: -2.00 D, thickness: 1.2 mm, outer diameter: 75 mm) is set on the coater. 2.5 ml of Emar 2F-30 (manufactured by Kao Corporation, main component: sodium lauryl sulfate 30% by weight) which is an anionic surfactant is dropped on the lens, and the spin coater is programmed. The lens is dried in a clean oven (manufactured by Espec Co., Ltd.) operated at a constant value at 85 ° C. to form a film on the lens.
(2) Application of colorant Evenly on the surface of the coated lens film obtained in (1) with a flat type printer (made by Mimaki Co., Ltd.) using disperse dye (colorant) as ink. Print. Then, set the printed surface face down on an aluminum donut-shaped holder that can hold the lens periphery.
(3) Coloring to optical plastic lens Step 1: 165 degrees C, 300 mmHg, 3 min hold, Step 2: 165 degrees C, 60 mmHg, 15 min hold, Step 3: return to atmospheric pressure And set. The lens of (2) is set in a vacuum oven for each holder, and heat treatment is performed under reduced pressure. The lens was taken out after the program operation, and after cooling, the surfactant and the remaining dye were washed away with water. Moreover, although the heat treatment was performed at a high temperature, the surfactant was easily removed by washing with water without alteration. The obtained lens was uniformly colored. Its luminous transmittance was 50%, and it was particularly darkly dyed. The results are shown in Table 1. The definition of each item and evaluation in Table 1 is as follows. The same applies to the following examples and comparative examples.

a) Coat for each item: Deposition condition after spin coating. Uniform prints have better evaluation: When the ink is printed on the film, the evaluation is good if it does not melt or repel. Shading: The darker the better the evaluation: Spots in the ink that has penetrated the lens Evaluated film shrinkage: Good evaluation if the film does not shrink when heated. Roughness: The texture of the lens surface when the ink that has penetrated into the lens does not diffuse sufficiently feels fine and rough. B) About evaluation S ... very good A ... good B ... possible C ... possible, unacceptable border D ... impractical-not appraisal

Example 2
In Example 1, (1) Application of surfactant to lens, surfactant used as coating agent is anionic surfactant, Perex SSL (manufactured by Kao Corporation, main component: alkyldiphenyl ether disulfonic acid) The same operation as in Example 1 was performed except that the change was made to (sodium). The colored lens thus obtained had a luminous transmittance of 65% and was uniformly colored. The results are shown in Table 1.
Example 3
78.7 parts by weight (in solid content) of 3% aqueous solution of sodium ancorbate (manufactured by Futaba Sangyo Co., Ltd.), an anionic surfactant, was added to 21.3 parts by weight of Emar 2F-30, an anionic surfactant. Of 26.9%) to prepare a mixed solution. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. When the luminous transmittance of the colored lens thus obtained was measured, it was 60%, and it was uniformly colored. The results are shown in Table 1.
Example 4
90 parts by weight of anionic surfactant Emar 2F-30, 10 parts by weight of nonionic surfactant Emulgen 1150S-70 (manufactured by Kao Corporation, main component: polyoxyethylene alkyl ether) in solid content Of 27.0%) and a mixed solution is prepared. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The luminous transmittance of the colored lens thus obtained was 65%. The results are shown in Table 1. The lens of Example 4 was particularly excellent in appearance when finished.

Example 5
To 44.4 parts by weight of anionic surfactant Emar 2F-30, Snowtex C (Nissan Chemical Industry Co., Ltd., SiO2 content 20 to 21% by weight, pH 8.5 to 9. 0, particle diameter 10-20 nm) is added to 55.6 parts by weight to prepare a mixed solution.
At that time, it is necessary to pay close attention to gelation. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The solid content of the surfactant (derived from Emar 2F-30) and colloidal silica (derived from Snowtex C) after drying in a clean oven is 54.5% by weight and 45.5% by weight, respectively.
The luminous transmittance of the colored lens thus obtained was 50%. The results are shown in Table 1. In addition, the lens of Example 5 was particularly excellent not only in darkness but also in appearance when finished.
Example 6
Anionic surfactant Sandet END (manufactured by Sanyo Chemical Industries, Ltd., main component: polyoxyethylene alkyl ether sodium sulfate salt) is added to 47 parts by weight of polyvinyl alcohol B-05 (manufactured by Denki Kagaku Kogyo Co., Ltd., molecular weight of about 500, hydrolysis degree: 88) 53 parts by weight of an aqueous solution is added to prepare a mixed solution. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The solid content of the surfactant (derived from Sandet END) and polyvinyl alcohol (derived from B-05) after drying in a clean oven is 69.9% by weight and 30.1% by weight, respectively.
The colored lens thus obtained had a luminous transmittance of 55% and was uniformly colored. The results are shown in Table 1.

Example 7
71.4 parts by weight of an aqueous B-05 solution of polyvinyl alcohol is added to 28.6 parts by weight of Sandet END, an anionic surfactant, to prepare a mixed solution. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The solid content of the surfactant (derived from Sandet END) and polyvinyl alcohol (derived from B-05) after drying in a clean oven is 50.0% by weight and 50.0% by weight, respectively.
The colored lens thus obtained had a luminous transmittance of 55% and was uniformly colored. The results are shown in Table 1. However, in Example 7, it is difficult to remove the coating, and the addition amount of the surfactant is considered to be around 50.0% by weight as the lower limit.
Example 8
64.8 parts by weight of polystron 619 (Arakawa Chemical Industries, Ltd., cationic acrylic resin) aqueous solution is added to 35.2 parts by weight of the anionic surfactant Emar 2F-30, and the mixture is mixed. Is made. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The solid contents after drying in a clean oven of a surfactant (derived from Emar 2F-30) and polyacrylamide (derived from Polystron 619) are equivalent to 70.0% by weight and 30.0% by weight, respectively.
The colored lens thus obtained had a luminous transmittance of 55% and was uniformly colored. The results are shown in Table 1.
Example 9
In Example 1, the liquid used as a coating agent in (1) Application of a surfactant to a lens was changed to a mixed liquid prepared as follows. Add 21.1 parts by weight of Joncrill 7100 (manufactured by Johnson Polymer Co., Ltd., Tg = 10 degrees C), which is a kind of acrylic emulsion, to 78.9 parts by weight of anionic surfactant Emar 2F-30, and mix. Make a liquid. The same operation as in Example 1 was performed except that the coating solution was changed. The solid contents after drying in a clean oven of a surfactant (derived from Emar 2F-30) and an acrylic emulsion (derived from Jonkrill 7100) are equivalent to 70.0% by weight and 30.0% by weight, respectively.
When the luminous transmittance of the colored lens thus obtained was measured, it was 55%, which was relatively dark and uniformly colored. The results are shown in Table 1.
Example 10
In Example 1, the liquid used as a coating agent in (1) Application of a surfactant to a lens was changed to a mixed liquid prepared as follows. To 58.3 parts by weight of anionic surfactant Emar 2F-30, 41.7 parts by weight of Jonkrill 7100, which is a kind of acrylic emulsion, is added to prepare a mixed solution. The same operation as in Example 1 was performed except that the coating solution was changed. The solid contents after drying in a clean oven of a surfactant (derived from Emar 2F-30) and an acrylic emulsion (derived from Jonkrill 7100) are equivalent to 50.0% by weight and 50.0% by weight, respectively.
The luminous transmittance of the colored lens thus obtained was measured to be 55%. The results are shown in Table 1. In Example 10, the color was relatively dark, but slight spots started to appear. As the addition amount of the surfactant, the lower limit is considered to be around 50.0% by weight.

Comparative Example 1
In Example 1, (1) Application of surfactant to lens, surfactant used as coating agent is amphoteric surfactant, Amphital 20N (manufactured by Kao Corporation, main component: lauryldimethylamine oxide) The same operation as Example 1 was performed except having changed into. The results are shown in Table 2. In Comparative Example 1, the coat at the time of processing was not uniform, and there were places where the coating deteriorated during heating and burned onto the plastic lens and could not be removed.
Comparative Example 2
Instead of the surfactant used as a coating agent in the application of (1) a surfactant to a lens in Example 1, the following solution is used. 68.2 parts by weight of Snowtex C, which is a kind of colloidal silica, is added to 31.8 parts by weight of anionic surfactant Emar 2F-30 to prepare a mixed solution. At that time, it is necessary to pay close attention to gelation. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in (1) Application of a surfactant to a lens in Example 1. The solid content of the surfactant (derived from Emar 2F-30) and colloidal silica (derived from Snowtex C) after drying in a clean oven is 41.2% by weight and 58.8% by weight, respectively.
The results are shown in Table 2. In Comparative Example 2, it was difficult to form a film first, and the processed film could not be completely removed.
Comparative Example 3
Instead of the surfactant used as a coating agent in (1) Application of surfactant to lens in Example 1, the following solution is used. To 90 parts by weight of distilled water, 10 parts by weight of B-05 (manufactured by Denki Kagaku Kogyo Co., Ltd., molecular weight of 500, hydrolysis degree of about 88) is added and stirred to obtain an aqueous solution. Except for this change, the same operation as in Example 1 was performed. The results are shown in Table 2. In Comparative Example 3, the coating at the time of processing was not uniform, and there were some portions that could not be removed because they were burned onto the plastic lens at the time of removal.
Comparative Example 4
The same operation as in Example 1 was performed except that Polystron 617 was used as a stock solution instead of the surfactant used as a coating agent in (1) Application of surfactant to lens in Example 1. It was. The results are shown in Table 2. In Comparative Example 4, there was a portion that was hardly colored and could not be removed because it was burned into the plastic lens at the time of removal.
Comparative Example 5
The same operation as in Example 1 was performed except that Joncrill 7100 was used as a stock solution instead of the surfactant used as a coating agent in (1) Application of a surfactant to a lens in Example 1. It was. The results are shown in Table 2. In Comparative Example 5, there was a portion that was hardly colored and could not be removed because it was burned into the plastic lens at the time of removal.
Comparative Example 6
Instead of the surfactant used as a coating agent in the application of (1) a surfactant to a lens in Example 1, the following solution is used. Add 40.7 parts by weight of Hydran HW-930 (Dainippon Ink Co., Ltd., Tg = 20 degrees C), which is a type of urethane emulsion, to 59.3 parts by weight of anionic surfactant Emar 2F-30. A mixed liquid is prepared. The same operation as in Example 1 was performed except that the product prepared in this procedure was used as a coating agent in Example 1 (1) Application of a surfactant to a lens. The solid contents after drying in a clean oven of the surfactant (derived from Emar 2F-30) and the urethane emulsion (derived from hydran HW-930) are respectively equivalent to 70.0% by weight and 30.0% by weight.
The results are shown in Table 2. In Comparative Example 6, it was difficult to form a film, and coloration was hardly observed. It is considered that an action like an acrylic emulsion cannot be obtained with a urethane emulsion.

Claims (8)

A film mainly composed of a surfactant is formed on a plastic substrate, a colored solution containing a colorant as a component is supplied to the surface of the film, and then heated to heat the colorant through the film. A colored plastic article obtained by transferring the film to water and then removing the film by washing with water. The surfactant as a film component formed on the plastic substrate is at least one selected from an anionic surfactant, a nonionic surfactant and a cationic surfactant. Item 2. A colored plastic article according to Item 1. The colored plastic article according to claim 1 or 2, wherein the surfactant, which is a film component formed on the plastic substrate, contains an anionic surfactant as a main component. The colored plastic article according to any one of claims 1 to 3, wherein a blending ratio of the surfactant in the film is 50% by weight or more. The colored plastic article according to any one of claims 1 to 4, wherein colloidal particles are added as a film component used in combination with the surfactant. The colored plastic article according to any one of claims 1 to 5, wherein a water-soluble polymer is added as a film component used in combination with the surfactant. The colored plastic article according to any one of claims 1 to 6, wherein an acrylic emulsion is added as a film component used in combination with the surfactant. A film forming process for forming a film mainly composed of a surfactant on a plastic substrate, and a colored solution supplying process for supplying a colored solution containing a colorant as a component to the surface of the film formed in the film forming process. In the same coloring solution supplying step, the same coloring agent that has penetrated into the same film is transferred to the plastic substrate through the same film by heating the same plastic substrate, and the same plastic is used in the coloring step. A method for producing a colored plastic article comprising a washing and removing step of washing and removing the same coating on the lens surface after the substrate is colored.