JPH10166515A - Laminated matter of functional substance and molded matter having hydrophobic surface, manufacture and use application thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily give properties such as antifungal properties, bactericidal properties, keeping fragrancy, anti-fogging properties and the like to the hydrophobic surface of a molded matter at low cost by a method wherein a laminated matter is produced by giving functional substance in minute polka dots to the hydrophobic surface of a plastic or the like. SOLUTION: A laminated matter, to which a functional substance is given, is produced by giving the functional substance consisting of an antifungal agent, a bactericidal agent, a fragrance or deodorant in minute polka dots, each of which is substantially independent from one another and has a diameter of 1-0.05mm on the hydrophobic surface of plastic or the like. In order to give the functional substance in polka dots on the hydrophobic surface, a coating liquid having the water or hydrophilic solvent of the functional substance is sprayed to the hydrophobic surface with an atomizer under the condition that the atomizer is fixed and a molded matter is moved or the atomizer is moved. Or by printing the functional coating liquid in drops with a reticulated or a large number of parallel lines-like screen or a gravure coater, the hydrophilic coating liquid coagulates into polka dots by means of its coagulating force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article such as a film or sheet made of a hydrophobic plastic having a surface layer of a functional substance, a method for producing the same, and an application of the molded article. Can be obtained very easily and at low cost, and are extremely effective for imparting properties such as antibacterial property, deodorant property and antifogging property to the molded product.

[0002]

2. Description of the Related Art It has been widely practiced to impart a functional substance to the surface of a hydrophobic plastic film or sheet to modify the surface. When a coating solution containing water as a medium is applied directly to a hydrophobic surface, there is no affinity between water and the hydrophobic surface, and the aqueous solution aggregates on the surface due to surface tension or cohesive force and becomes mottled. And it is impossible to apply the aqueous solution uniformly.

Therefore, conventionally, a hydrophilic primer layer is provided on the surface of a hydrophobic plastic, or a corona discharge treatment,
After applying a discharge treatment such as a plasma discharge treatment, an energy ray irradiation treatment such as an ultraviolet ray irradiation and the like to make the surface hydrophilic,
A coating solution using water as a medium is applied. However, this method has a drawback that the cost is high because steps such as a primer treatment and a discharge treatment are required.

[0004]

SUMMARY OF THE INVENTION The present invention improves the above-mentioned drawbacks of the conventional products and improves the hydrophobicity of the molded product without pre-treatment such as primer treatment, discharge treatment, and energy beam irradiation treatment. Laminate having a layer of a functional substance directly and evenly formed on a functional surface, and a method for forming the same, which is easily and inexpensively applied to the hydrophobic surface of the molded article by using this method. And properties such as anti-fogging property.

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a laminate by adding a functional substance to a minute dot-like polka dot pattern on a hydrophobic surface of plastic or the like. It can be obtained by spraying or printing a coating solution using water or a hydrophilic solvent of a functional substance as a medium on the surface. And these functional substances include antibacterial agents,
Fungicides, fragrances, antifoggants and the like are included.

The substrate to which the present invention is applied is a molded article of a thermoplastic resin such as polyethylene, polypropylene, polyester, polyvinyl chloride or polystyrene, or a thermosetting resin such as an epoxy resin, a phenol resin or a melamine resin. Metals, ceramics, and the like are included in addition to molded products whose surfaces are coated with the above resin. In addition, since the substrate is particularly effective on a water-repellent surface, it is coated with a water-repellent resin such as a fluororesin or a silicone resin, or a hydrophilic surface or a hydrophobic surface, regardless of the hydrophobic surface. It is effective to apply it to a molded article. The substrate is often a film, a sheet, or the like, but is not limited thereto.

[0007] A coating liquid of a functional substance is applied to a hydrophobic surface in the form of minute dot-like polka dots. At this time, each point is substantially independent and has a diameter of 2 mm or less. 1 mm to 0.05 mm is preferred. The area of the portion attached to the dotted polka dot pattern is 50% to 90%, preferably 60% to 80% of the area of the target portion to be applied in one coating process. However, it is also possible to repeat the dot application and the drying several times to apply the entire target portion. The concentration of the functional substance at the time of application is
Depending on the type of substance, usually 1% by weight to 1%
0% by weight.

When a functional substance is added to the above-mentioned state,
Although dotted, the hydrophobic substance can be substantially uniformly applied to the hydrophobic surface. In addition, when the diameter and area of each point deviate from the above range, water or hydrophilic solvent at each point gathers due to surface tension or cohesion, resulting in a patchy and non-uniform pattern and uniformity. Application becomes impossible.

As described above, there are the following methods for providing a functional substance with a dot-like polka dot pattern on a hydrophobic surface. That is, one of them is a spraying method, in which a coating liquid using a water or hydrophilic solvent of a functional substance as a medium is sprayed on a hydrophobic surface by a sprayer. As a method of spraying, there is a case where a sprayer is fixed and sprayed on a surface while moving a molded product (for example, a film or a sheet), or a case where the sprayer is moved and sprayed on the surface of a molded product.

[0010] Examples of the hydrophilic solvent include lower alcohols such as methanol and ethanol, hydrophilic solvents such as acetone and ethyl ether, and mixtures of these solvents with water. Functional substances are not always hydrophilic,
The coating solution is used in the form of a solution or a dispersion such as a suspension or an emulsion, preferably as an aqueous solution or an aqueous dispersion, since it also contains a hydrophobic substance.

As another method of applying a functional substance to a hydrophobic surface in a dot-like manner, a functional coating solution is printed in a dot-like manner using a mesh-like or multiple parallel-line screen or a gravure coater. There is a way. Further, as a characteristic method of the present invention, by printing water or a hydrophilic coating solution of the functional substance in a mesh or a plurality of parallel lines, the hydrophilic coating solution is aggregated into a dot-like polka dot pattern by cohesive force. And complete the print. In this case, the line width of the mesh or parallel line is 1 m
m or less.

The functional substance used in the present invention includes an antibacterial agent, a bactericide, a fragrance, a deodorant, an antifogging agent and the like as described above. Examples of antibacterial agents and bactericides include metal compounds such as silver compounds and copper compounds, phenolic compounds, and organic compounds such as chlorhexidine chloride and benzalkonium chloride. Also high-molecular antibacterial substances such as chitosan,
Natural antibacterial substances such as wasabi extract and hinoki oil are also used, and these are very effective as antibacterial agents that do not affect the human body.

In particular, chitosan is a polymer and can be subjected to durable processing from the point of forming a tough film. In the treatment, it is preferable to apply an aqueous solution of an organic acid salt of chitosan to a hydrophobic surface. Specific examples of the organic acid include acetic acid, oxalic acid, lactic acid, citric acid, malic acid and the like. The chitosan preferably has a deacetylation ratio of 60% or more.

Examples of the fragrance include natural essential oils mainly composed of terpene hydrocarbons and extracts thereof, and specifically, pine oil of turpentine, α-limonene of lemon oil and α-limonene of orange oil. Eucalyptus oil, mildenol, terpineol and the like. Further, lavender oil, rose oil, jasmine oil, peppermint oil and the like extracted from musk and flowers are also added as fragrances. Further, a higher fatty acid alkali metal salt and a metal soap are mixed as a retaining agent for these fragrances, and the mixture is applied as a dispersion of water or a hydrophilic solvent.

Examples of the deodorant include organic compounds such as fumaric acid, and natural products such as persimmon fruit extract, polyphenols, and plant extracts. These are of course used as solutions or dispersions of water or hydrophilic solvents.

Further, examples of the antifogging agent include polyethylene glycol, polyvinylpyrrolidone and the like. Used as a solution or dispersion of water or a hydrophilic solvent.

Next, the present invention will be further described with reference to examples.

Example 1 A transparent polyvinyl chloride sheet (240 mm ×
20mm, thickness 100μ) prepared by heating vacuum forming
A square tray for holding fresh confectionery, small fruits, etc. was created.
On the other hand, an antibacterial agent, chitosan, was dissolved in an aqueous lactic acid solution (chitosan 5% by weight, lactic acid 3% by weight) as a coating solution. The coating solution was placed in a spray container and applied to the inner surface of the square tray by a spray method. The applied coating liquid is placed in tray 1
The amount is 1.1 g per piece, and the coating liquid is applied to fine dot-like polka dots having a diameter of 1 mm or less.

Then, it was dried with hot air at 60 ° C., and the antibacterial property of the inner surface of the square tray was evaluated. That is, about 0.75 g of a sample was cut out from the tray coated with chitosan, and approximately 1 cm ×
When the viable cell count after shaking at 25 ° C. for 1 hour was measured by a shake flask method using a Staphylococcus aureus as a test bacterium, the viable cell count was 15,
100 samples became 0 after 18 hours, indicating excellent antibacterial properties.

[0019]

[Embodiment 2] The distance between the lines is 2 mm and the width of the lines is 0.5 mm.
Was screen-printed on one side of a polyethylene film using a screen consisting of a number of parallel lines. The coating solution was prepared as follows. That is, 1 part by weight of a turpentine-based natural essential oil, and a trace amount of rose oil mixed with 10 parts by weight of a gel-like substance obtained by mixing a sodium salt of a higher fatty acid having 18 or more carbon atoms and a magnesium salt of a higher fatty acid in a ratio of 1: 1 by weight. Then, 1 part by weight of the obtained mixture was stirred, mixed and dispersed in 30 parts by weight of water to obtain a coating liquid. The screen printing was performed using this coating solution.

On the surface of the obtained polyethylene film, a fragrance such as turpentine-based natural essential oil was printed on the surface in a fine dot-like polka dot pattern, and an elegant fragrance was diffused. This was used as a wrapping paper for cosmetic tissue paper, and wrapped with the fragrance-applied surface on the inside. As a result, the fragrance permeated into the tissue, and a high-class feeling was obtained.

[0021]

Embodiment 3 Polyethylene glycol 1 as a coating solution
A 0% by weight aqueous solution was prepared. This coating liquid was applied by spraying to the inside of a square tray obtained from the transparent polyvinyl chloride sheet of Example 1 to obtain a tray in which the coating liquid was attached to fine dot-like polka dots having a diameter of 1 mm or less. .

When the steamed chrysanthemum was stored in the tray, covered, and left to stand, no water droplets were formed on the inner surface of the tray, and the state of the chrysanthemum inside could be clearly observed. On the other hand, water droplets adhered to the inner surface of the tray not subjected to the polyethylene glycol treatment, and it was difficult to check the internal state.

[0023]

Example 4 Using the aqueous solution of chitosan-lactic acid used in Example 1 as a coating solution, screen printing was performed on one surface of a transparent polyvinyl chloride sheet. The screen used was Example 2.
In the same manner as in Example 2, a dot-shaped polka-dot printed product was obtained. The printed polyvinyl chloride sheet was vacuum-formed with the print side inward to make a tray.

The antibacterial property of this tray was measured by the shake flask method in the same manner as in Example 1, and the same antibacterial effect as in Example 1 was obtained.

[0025]

[Effect] The laminate of the present invention has a hydrophobic surface with corona discharge,
A place where the hydrophilic substance and the hydrophobic surface are in direct contact with each other without performing discharge treatment such as plasma discharge, high-energy radiation treatment such as ultraviolet treatment, electron beam treatment, or hydrophilization treatment such as hydrophilizing agent treatment. There are features.

That is, in the present invention, the cost can be reduced because the hydrophilic treatment step can be omitted on the hydrophobic surface. The laminate of the present invention may employ a method in which a binder or the like is used in order to further increase the durability (such as abrasion resistance).

When an antibacterial agent or a bactericide is applied to a food container using the laminate of the present invention, for example, as shown in E. coli O-157, which has recently become a social problem, Preservation before eating, contamination during transportation, and infection accidents can be easily and easily prevented.

In addition, a fragrance, a deodorant, or the like as a functional substance can be easily and inexpensively applied to food containers, cosmetic containers, hand wipes, and the like, thereby enriching life. Further, when an anti-fogging agent is used as a functional substance, it is possible to prevent the fogging of transparent sheets and transparent packaging products in greenhouses and the like, and not only can check the internal state well, but also in the greenhouse etc. Can be prevented from being shut off.

Claims (10)

[Claims] 1. A laminate in which a functional substance is provided in a minute dot-like polka dot pattern on a hydrophobic surface such as plastic. 2. The laminate according to claim 1, wherein the hydrophobic surface and the dot-like polka dot functional material are in direct contact with each other. 3. The laminate according to claim 1, wherein the diameter of each point forming a dot-like polka dot pattern is 1 mm to 0.05 mm. 4. The laminate according to claim 1, wherein the functional substance is an antibacterial agent or a bactericide. 5. The laminate according to claim 4, wherein the antibacterial agent is chitosan or an organic acid salt of chitosan. 6. The laminate according to claim 1, wherein the functional substance is a fragrance or a deodorant. 7. The laminate according to claim 1, wherein the functional substance is an antifogging agent. 8. The method according to claim 1, wherein a solution or a dispersion of water or a hydrophilic solvent of the functional substance as a main medium is applied to a hydrophobic surface of a plastic or the like by a spray method and dried. A method for producing a laminate according to any one of the above. 9. The method according to claim 1, wherein a solution or a dispersion of water or a hydrophilic solvent of the functional substance as a main medium is applied to a hydrophobic surface of a plastic or the like by a printing method and dried. A method for producing a laminate according to any one of the above. 10. The method for producing a laminate according to claim 9, wherein the functional substance is printed on the hydrophobic surface in a network or a plurality of parallel lines, and a dot-like polka dot pattern is imparted by cohesive force.