JPH07256848A - Manufacture of antibacterial melamine decorative plate - Google Patents

Abstract

PURPOSE:To obtain an antibacterial melamine decorative plate having physical properties of heat resistance, water resistance, etc., with excellent compatibility with resin and stability for weak acidic properties of resin liquid without decreasing qualities in manufacturing steps such as discoloring, a reduction in an antibacterial effect due to heating of drying and molding steps of a resin- impregnated sheet. CONSTITUTION:The method for manufacturing an antibacterial melamine decorative plate comprises the steps of impregnating an overlay sheet or a decorative sheet with aqueous soluble melamine resin solution in which polyoxyethylene (dimethylimino) ethylene (dimethylimino) ethylene chloride of antibacterial agent of at least 2wt.% or more is added to resin nonvolatile content, drying it to obtain resin-impregnated sheet, so placing the sheet as to become a decorative plate surface layer, heating and pressurizing to mold it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an antibacterial melamine decorative board used for interior equipment, housing equipment, kitchens, table tops and the like.

[0002]

BACKGROUND ART Melamine decorative boards have a wide variety of uses because they have excellent physical properties such as heat resistance, hardness, abrasion resistance, water resistance, and stain resistance. They are used for bathroom wall surfaces, vanities, washstands, and kitchens. It is often used under conditions suitable for the growth of mold and bacteria due to warm and humid conditions, such as sinks and tabletops, and the adhesion of nutrients. Also, in public facilities, especially in applications such as hospitals. Since it may be contaminated with pathogenic bacteria, it has been desired to impart antibacterial properties from the viewpoint of hygiene.

However, the general melamine decorative board is more resistant to bacteria than the decorative laminated board made of a natural product, but it cannot prevent the propagation thereof depending on the environment in which it is used.

In order to solve these problems, a method of adding an organic antibacterial agent to a resin or a method of adding metal ions having an antibacterial action such as silver and copper to zeolite or silica is added to the resin. However, antibacterial properties of veneer materials, such as the method of adhering to the surface of the decorative paper, have been used, but these methods are not always effective for the melamine decorative board, and they are not effective for long-term use. It does not have an antibacterial effect and does not combine the generally required appearance and physical properties.

[0005]

In the method of adding an organic antibacterial agent to a melamine resin, many of the antibacterial agents are harmful to the human body and are generally unstable to heat, so that the heat molding step There is a problem that the surface appearance of the decorative plate is likely to be deteriorated due to discoloration or the like because many of them are deteriorated and the effect is apt to be deteriorated, and many of them are affected by ultraviolet rays when used for a long time.

Further, it is soluble in a solution of a water-soluble melamine resin, stable in a weakly acidic resin solution, and in a drying process of a resin-impregnated sheet and a heating and pressing process.
Does not deteriorate even when heated at 20 to 160 ° C,
It is necessary to maintain the antibacterial effect, and it has been difficult to satisfy such conditions in the past.

When an antibacterial agent in which metal ions are carried on an inorganic carrier such as zeolite or silica gel is attached to overlay paper or decorative paper and used as a decorative sheet material, the antibacterial agent is coated with a resin layer. As a result, the effect is reduced, and when the antibacterial agent is exposed on the surface, metal ions may be eluted to change the appearance and physical properties of the decorative plate. Further, since the antibacterial agent supported on the inorganic carrier does not dissolve in the water-soluble melamine resin solution and settles, it is difficult to uniformly disperse and adhere it to the paper.

According to the present invention, a decorative board is manufactured by using a resin solution prepared by dissolving poly-oxyethylene (dimethylimino) ethylene (dimethylimino) ethylene chloride, which is an antibacterial agent, in a solution of a water-soluble melamine resin. It has excellent compatibility with resin, is stable against weak acidity of resin liquid, and may cause quality deterioration in the manufacturing process such as drying process of resin impregnated sheet, discoloration due to heating in molding process, decrease in antibacterial effect, etc. The purpose is to obtain an antibacterial melamine decorative board having physical properties such as heat resistance and water resistance.

[0009]

The present invention provides a method for producing a melamine decorative board in which poly-oxyethylene (dimethylimino) is added to the nonvolatile component of the water-soluble melamine resin.
The overlay paper or the decorative paper is impregnated with a solution of the water-soluble melamine resin added with ethylene (dimethylimino) ethylene chloride so as to have a content of at least 0.2% by weight, and then dried to obtain a resin-impregnated sheet. The method for producing an antibacterial melamine decorative board is characterized by comprising the steps of: obtaining the resin-impregnated sheet so as to form a decorative board surface layer on a base material;

The water-soluble melamine resin used in the antibacterial melamine decorative board of the present invention is a melamine resin obtained by condensing melamine and formalin, similarly to the known resin for melamine decorative board, and if necessary, In some cases, various modifications may be performed for the purpose of imparting plasticity, etc. In order to allow the resin to be impregnated into paper, it is used in a state of being dissolved in a solvent containing water as a main component. As the solvent, it is also possible to use water or a mixture of water and an organic solvent having compatibility with water, such as methanol, and water.

The antibacterial agent poly-oxyethylene (dimethylimino) ethylene (dimethylimino) ethylene chloride (hereinafter referred to as PMIEC) is added to the water-soluble melamine resin directly or as an aqueous solution, and then mixed and mixed. Dissolve. At a content of 0.2% by weight or more based on the nonvolatile component of the water-soluble melamine resin, PMIEC has a remarkable antibacterial effect against Staphylococcus aureus, Pseudomonas aeruginosa and the like. As the amount of antibacterial agent added to the resin increases, the antibacterial effect also increases, but the content of 5% by weight or more from the viewpoint of quality such as economic problems due to rising material prices and deterioration of water resistance and coloring of melamine decorative board. The addition of PMIEC such that is not practically preferable.

The resin liquid used for impregnating the base paper of the melamine decorative board is generally weakly acidic, to which an acidic curing agent is added, but PMIEC dissolves well in a solution of a water-soluble melamine resin, Stable against weak acidity of resin liquid. The solution of the water-soluble melamine resin to which PMIEC has been added is adjusted to have a desired concentration and viscosity by adding a curing agent, an internal release agent, etc., if necessary, and is overlaid using an impregnation drying device. A paper or a decorative paper is impregnated and dried to obtain a resin-impregnated sheet.

In the antibacterial melamine decorative board of the present invention, an overlay paper similar to a general melamine decorative board, or
Decorative paper can be used and can be impregnated under normal impregnation conditions. For overlay paper, 10-80g /
A large amount of thin paper made of α-cellulose that becomes transparent by resin impregnation of m ² is used, and the amount of resin adhered is suitably in the range of 120 to 300% by weight in terms of nonvolatile content with respect to the base paper. As the decorative paper, a colored or printed base paper containing titanium oxide at 50 to 200 g / m ² is used and impregnated with a required amount of resin.

The drying condition for the resin-impregnated sheet is generally 1
Water and the like are evaporated by hot air drying at 00 to 180 ° C. In the present invention, it is preferable to dry at a temperature of 160 ° C. or less from the viewpoint of thermal stability of PMIEC.

The melamine decorative board is placed and laminated such that the resin-impregnated overlay paper or the resin-impregnated decorative paper serves as the surface layer. In the present invention, only the impregnated paper constituting the surface layer is used. By using a resin containing PMIEC as the antibacterial agent, the effect can be obtained with a small amount of the antibacterial agent.

The base material of the antibacterial melamine decorative board of the present invention is a wood board material such as kraft paper or plywood impregnated with phenol resin, particle board, fiber board, inorganic board material such as asbestos cement calcium silicate board, steel plate, aluminum. Although metal plates such as plates can be used, the so-called loose melamine decorative board is a stack of phenol impregnated kraft paper with melamine resin impregnated decorative paper placed on top of it, and melamine resin impregnated overlay paper is further laminated if necessary. It is thermo-compressed and has a general purpose.

[0017] Laminated decorative board constituent materials such as a base material, resin-impregnated decorative paper, resin-impregnated overlay paper, etc.
Similar to the usual molding of a melamine decorative board, it is inserted between hot plates of a hot press, heated and pressed at a molding temperature of 160 ° C. or less and cured to obtain an antibacterial melamine decorative board.

[0018]

EXAMPLES The parts and% described in the examples below represent parts by weight and% by weight, respectively. Examples 1 to 3 Formaldehyde and melamine were condensed under a mildly alkaline condition of PH9 at a compounding ratio of 1: 1.5 to obtain a methylolated melamine resin aqueous solution. The nonvolatile content of the melamine resin in this methylolated melamine resin aqueous solution was 66%. For 100 parts of the nonvolatile content of this methylolated melamine resin aqueous solution, PMIEC7 which is an antibacterial agent is used.
0.5%, 1.0, and 2.0 parts of 0% aqueous solution were added, respectively, and dissolved by stirring. Further, a latent curing agent (Catanit A;
Nitto Kagaku) 0.5 part, internal release agent 0.1 part,
A resin solution for impregnation of antibacterial melamine decorative board base paper was obtained. This resin solution for impregnating decorative paper is composed of 66 parts of melamine resin and 34 parts of water.
Part, latent hardener 0.5 part, internal release agent 0.1 part, PM
The composition of the IEC is 0.35 parts, 0.7 parts, and 1.4 parts, respectively.

This resin solution for impregnating the decorative paper is treated with titanium dioxide 2
120 g / m ² basis weight containing 5% of white decorative paper was impregnated so that the amount of resin adhered was 145 g / m ² in non-volatile content, and dried for 2 minutes with hot air at a temperature of 120 ° C using a horizontal hot-air circulation dryer. Then, a resin-impregnated decorative paper, which is a resin-impregnated sheet for the surface of the decorative plate, was obtained.

As a base material, unbleached kraft paper having a weight of 180 g / m ² contains phenol resin as a non-volatile component and a resin adhesion amount of 110
Place the above resin-impregnated decorative paper on top of 5 sheets of core impregnated paper impregnated to g / m ² and insert it between hot-press hot plates by sandwiching it with a gloss finish stainless steel plate. Then, heat and pressure are applied for 50 minutes under the molding conditions of a temperature of 140 ° C and a pressure of 60 kg / cm ² , and after cooling down to 30 ° C under pressure, they are dismantled and have a 1.2 mm thick glossy white antibacterial property. A melamine decorative board was obtained.

Comparative Examples 1 to 3 In Comparative Example 1, a decorative board was prepared under the same conditions as the antibacterial melamine decorative board of Example 1 except that the antibacterial agent PMIEC was not added to the melamine resin solution.

In Comparative Example 2, instead of PMIEC as an antibacterial agent, an inorganic antibacterial agent carrying a thiosulfo silver complex salt was added in 2 parts per 100 parts of the non-volatile content of the methylolated melamine resin. A veneer was made under the same conditions as above.

Comparative Example 3 was the same as Example 1 except that 2 parts of a quaternary ammonium silicon antibacterial agent was added as an antibacterial agent to 100 parts of the nonvolatile content of the methylolated melamine resin instead of PMIEC. I made a veneer. Tables 1 and 2 show the results of the antibacterial property test and the physical property evaluation test of the melamine decorative boards of Examples 1 to 3 and Comparative Examples 1 to 3.

Test method Antibacterial test: Staphylococcus
cus aureus) Escherichia coli (Escherich)
ia coli), Pseudomonas (Pseudomon as
aeruginosa), the viable cell count is measured by the bacterial count method of the Textile Products Sanitation Council (hereinafter referred to as the SEK method). Physical property evaluation test: Thermosetting resin veneer test method (JIS K
6902), the appearance, boiling resistance, and heat resistance are tested.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

In the present invention, PMI which is an antibacterial agent is used.
EC mixes well with the water-soluble melamine resin solution and dissolves, so that it becomes a solution having a uniform composition and does not cause precipitation or phase separation as in the case of adding a usual inorganic antibacterial agent,
It is possible to maintain a stable content of the antibacterial agent with respect to the resin.

The resin solution for impregnating the base paper exhibits weak acidity, but PMIEC withstands weak alkali or weak acidity, so that the antibacterial property does not deteriorate. Since the PMIEC contained in the melamine resin has a heat resistance of 160 ° C, it withstands the drying temperature of the resin-impregnated sheet and the temperature of hot press molding by hot pressing. Yellowing due to heat deterioration such as
Discoloration is unlikely to occur and the antibacterial property does not deteriorate.

Further, the antibacterial melamine decorative board obtained by the present invention is not colored by itself due to the antibacterial agent, and is not colored over time due to elution of metal ions. In the present invention, even if the amount of PMIEC added is 0.35% with respect to the melamine resin, a remarkable effect is observed on Staphylococcus aureus, and the content is small compared to other antibacterial agents.
Excellent antibacterial effect is obtained.

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Claims (1)

[Claims] 1. A method for producing a melamine decorative board, wherein at least 0.2% by weight of poly-oxyethylene (dimethylimino) ethylene (dimethylimino) ethylene chloride is contained in the nonvolatile component of the water-soluble melamine resin. A step of impregnating overlay paper or decorative paper with a solution of the water-soluble melamine resin added in an amount to obtain a resin-impregnated sheet by drying, and so that the resin-impregnated sheet constitutes a decorative board surface layer. A method for producing an antibacterial melamine decorative board, which comprises the steps of placing on a base material and heat-pressing.