JPH0725900B2 - Moisture absorbent sheet and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a moisture absorptive and desorptive sheet which can be used in various fields as an interior material and a surface material of equipment to prevent dew condensation, and a method for producing the same.

[Conventional technology]

Vinyl chloride as wood-like interior materials, OA equipment, optical equipment, home appliances, kitchen appliances, furniture, office equipment, stationery, office supplies, crafts, surface materials such as stairs and floors, or cosmetic materials Sheets and decorative boards made of soft or hard synthetic resin such as resin, acrylic resin, phenol resin, and melamine resin are often used. As a natural material, a thin plate such as wood or cork, or a decorative plate formed by molding its powder into a plate shape,
Decorative sheets made of paper, cloth, etc. are used.

Further, by adding a polymer hygroscopic agent consisting of a highly water-absorbent resin in a vinyl chloride resin to form a sheet, and by embedding by dispersing the polymer hygroscopic agent fine powder in the sheet-shaped vinyl chloride resin layer, Attempts have also been made to impart hygroscopicity to vinyl chloride resin sheets.

[Problems to be Solved by the Invention] Of the above-mentioned conventional surface materials and cosmetic materials, synthetic resin decorative boards and decorative sheets have a surface that is difficult to stain and easy to wipe off even if soiled, but has no moisture absorption and desorption properties. For this reason, dew condensation or stuffiness is likely to occur, and depending on the intended use, the texture of the surface such as gloss and touch is not sufficiently satisfactory. A soft synthetic resin sheet containing a plasticizer, such as a soft vinyl chloride resin sheet, releases the plasticizer during use, and the sheet hardens and deteriorates.

Although the decorative sheet made of paper or cloth has moisture absorption and desorption properties, it easily stains and it is difficult to wipe off the attached stain. A plate or sheet made of wood or cork has a good texture and is excellent in moisture absorption and desorption, but it is easily soiled, it is difficult to wipe off adhered soil, and it is expensive.

Further, in a vinyl chloride resin sheet in which a polymeric hygroscopic agent is dispersed and embedded, the hygroscopic agent exposed on the sheet surface absorbs moisture well,
Since the hygroscopic agent buried in the resin layer is covered with a vinyl chloride resin having no moisture permeability, the hygroscopic ability is significantly impaired, and the water once absorbed is difficult to be released due to the same reason, Sufficient moisture absorption and desorption cannot be expected.

Therefore, the present invention is excellent in moisture absorption and desorption and antifouling properties, dew condensation,
It is an object of the present invention to provide a moisture absorptive and desorptive sheet having an effect of preventing stuffiness and an excellent feeling, and a method for producing the same.

[Means for solving problems]

In order to achieve the above object, the present inventors have conducted extensive studies, by mixing a wood powder to a moisture-permeable synthetic resin such as a moisture-permeable polyurethane resin to form a sheet, excellent moisture absorption and release properties, The inventors have found that a sheet having a warm texture and a touch, a smooth surface, and excellent antifouling properties can be obtained, and completed the present invention.

That is, the present invention provides a moisture absorptive and desorptive sheet obtained by embedding wood powder in a moisture permeable resin layer having a moisture permeability of a film having a thickness of 10 μm measured by JIS Z-0208 B method of 1000 g / m ² · 24H or more. Use as a summary.

Still another aspect of the present invention is to form a sheet by uniformly mixing a moisture-permeable synthetic resin and wood powder, applying the obtained compound uniformly on the surface of a base material, heating and drying, and peeling from the base material. The gist is the method for manufacturing a moisture absorptive and desorptive sheet according to claim 1.

The moisture-permeable resin used in the present invention is not particularly limited as long as it is a solvent-soluble, hardly swellable with water and is a moisture-permeable resin having a film-forming ability, but a known moisture-permeable polyurethane resin is preferably used. Other than these, for example, vinyl alcohol resin, vinyl acetate resin, acrylic resin, amino acid resin, etc. can be used. These moisture permeable resins are required to have a moisture permeability of a film (film thickness 10 μm) measured by JIS Z-0208 B method of 1000 g / m ² · 24H or more. When the moisture permeability of the moisture-permeable resin used in the present invention is smaller than this, absorption and release of water to the wood powder in the moisture-permeable resin through the moisture-permeable resin is not smoothly performed,
It cannot exert sufficient dew condensation prevention effect. The wood powder used in the present invention is not particularly limited to the type of wood,
A powder of coniferous trees having a low oil content such as fir tree, stalks, and cedar and having excellent hygroscopicity and aromaticity is preferable. Further, cork powder or the like can be used. As the wood powder, wood or the like is pulverized to a finer than 10 mesh, preferably 20 mesh. If it is coarser than 10 mesh, it is difficult to continuously apply it at the time of forming a sheet described later.

In order to produce the moisture absorptive and desorptive sheet of the present invention, the moisture permeable resin is usually used by dissolving it in an organic solvent, but it may be in the form of an emulsion. The solid content in these solutions or emulsions is adjusted to 10 to 50% by weight, and the solution viscosity is adjusted to 100 to 5000 CPS. Next, the wood flour and other additives, if necessary, are appropriately added to this solution and uniformly mixed to prepare a compound.

The mixing ratio of the wood flour and the moisture-permeable resin is preferably 10 to 500 parts by weight of wood flour per 100 parts by weight of the resin solid content in the solution. 500
If the amount is more than parts by weight, the fluidity is not sufficient for coating on a base material such as release paper at the time of forming a sheet, which is not suitable. On the other hand, if it is less than 10 parts by weight, the moisture absorbing / releasing performance of the sheet and the dew condensation preventing performance are deteriorated, which is not suitable.

When mixing the wood powder, it is important to uniformly mix and disperse it by using an appropriate method such as a dissolver, a homodisper, or a paint roll.

The viscosity range of the compound having fluidity and capable of uniformly coating the base material is 50000 CPS (25 ° C) or less.

Further, when a powder of a polymer hygroscopic agent such as isobutylene-maleic acid copolymer, polyacrylic acid salt or the like or an inorganic hygroscopic agent such as bentonite or zeolite is added, the moisture absorbing / releasing performance is further enhanced.

In carrying out this invention, various dyes, pigments, weathering agents, deodorants, fragrances, mildew-proofing agents, flame retardants, matting agents and other fillers, etc. may be added as necessary in addition to the above-mentioned compounding agents. Can be added appropriately.

It is also possible to add a thermal decomposition type or microcapsule type foaming agent to the above compound to foam the coating film on the base material after coating the base material.

As a method of mixing various compounding agent components as described above and applying the prepared compound to a substrate such as release paper, a known coating method such as gravure coating, doctor blade coating, reverse roll coating, and extrusion coating is appropriately used. Can be adopted.

In some cases, instead of using a solution or emulsion of a moisture permeable resin, a moisture permeable thermoplastic resin and wood powder may be used to form a sheet using an extruder.

The compound is continuously applied to a base material such as release paper to a constant thickness, heated to a predetermined temperature and dried. The thickness of the coating film after drying is 50 to 5000 μ, and particularly preferably 100 to 1000 μ. The drying temperature is usually 40 to 200 ° C, and the solvent evaporates if heated at this temperature for several minutes. Then, after cooling, the sheet is peeled from the substrate and wound into a roll.

As a makeup method for the surface of the sheet, various methods such as embossing on the coated surface after printing and printing various colors and patterns can be adopted. Also, by applying an adhesive or pressure-sensitive adhesive to the back surface of the peeled sheet and sticking a release paper or the like, a sheet can be easily adhered at the time of sticking.

[Action]

The sheet of the present invention is a moisture absorptive and desorptive sheet composed of a moisture-permeable urethane resin and wood powder, a filler, etc., which absorbs and absorbs moisture quickly in response to changes in humidity, and when used as a surface material for interior materials and equipment. , Very effective in preventing dew condensation.

That is, when the moisture absorptive and desorptive sheet of the present invention is used by being attached to the surface of a wall or device, when the humidity is high, water vapor permeates into the sheet through the moisture permeable resin layer and temporarily penetrates into the wood powder inside the sheet. It is occluded. Then, when it becomes a dry state, the moisture once occluded is again released from the sheet surface through the moisture permeable resin layer, so that it can absorb and release moisture well following environmental changes in humidity. As a result of this breathing action, the dew condensation phenomenon on the seat surface is suppressed.

Furthermore, since it is filled with wood powder, it has a heat insulating property, and the dew condensation preventing action is further enhanced.

Further, the moisture absorptive and desorptive sheet of the present invention has a surface of wood powder covered with a moisture permeable resin, so that the surface is non-porous and does not become clogged even if dirt is attached, by a dry cloth or a water wipe. Since dirt can be easily wiped off, the natural texture peculiar to wood flour can be maintained for a long time and the moisture permeability does not deteriorate. Further, since the sheet has hygroscopicity, it also has an antistatic effect.

The sheet of the present invention is a house, a store, an interior of a house such as an office,
Elevators, automobiles, railway vehicles, transportation equipment such as ships, interior materials such as equipment, computers, OA equipment such as word processors, optical equipment such as cameras and microscopes, telephones, televisions, stereos,
Home appliances such as videos, kitchen appliances such as cabinets, sinks, cupboards, furniture such as chests, desks, chairs, bookcases, office equipment, albums, book covers, stationery such as notebooks and office supplies, bags, packages, makeup It can be applied to various fields such as daily necessities such as boxes, crafts, surface materials such as stairs and floors.

〔Example〕

Example 1 Breathable urethane resin (manufactured by Toyo Tire & Rubber Co., Ltd .: NY814)
A film having a thickness of 20 μm was prepared from the solution of No. 1 by the knife coater method, and the moisture permeability thereof was measured by the JIS Z0208B method, and was 4300 g / m ² · 24H.

Next, add 80 mesh wood flour to this solution and
100 parts by weight of wood flour was added per 100 parts by weight, and the mixture was uniformly mixed using a paint roll to prepare a compound. This compound by knife coating method,
Uniformly coated on release paper, heated and dried at 70 ° C for 2 minutes in a heating oven, cooled, and then peeled off the sheet from the release paper to form a moisture-permeable urethane resin layer mixed with wood powder.
A sheet of 260μ was obtained.

FIG. 1 is a cross-sectional view showing the constitution of the moisture absorptive and desorptive sheet of the present invention obtained by the above method. In the drawing, (1)
Is a moisture-permeable urethane resin, and (2) is wood powder.

When the above-mentioned sheet and the vinyl chloride resin sheet were respectively stuck to the surface of the cosmetic case and used, the vinyl chloride sheet had a glossy surface, lacked a soft texture, and had a cool feel. Also, when I held it in my hand for a long time, sweat adhered.

On the other hand, the sheet to which the sheet of the present invention was adhered had a touch and warmth of natural wood, and was excellent in texture compared to the vinyl chloride sheet. Further, since the sheet of the present invention has a moisture absorbing / releasing property, even if it is held by hand for a long time, it does not sweat and does not feel stuffy.

Further, since the sheet of the present invention has no base material, it has flexibility,
Especially when a moisture-permeable urethane resin is used as the moisture-permeable resin,
Rich in flexibility and elasticity, when pasted on the surface of an article,
It can be easily applied to corners, etc. and can be applied neatly.

Further, when a book cover was prepared using the moisture absorptive and desorptive sheet of the present invention, a book cover having a good feel and a high quality feel was obtained.

〔The invention's effect〕

The moisture absorptive and desorptive sheet of the present invention has a natural texture unique to wood flour, and is excellent in moisture absorptive and desorptive properties due to the wood flour and the moisture permeable resin,
It is extremely effective in preventing dew condensation, and has a soft, warm feel and texture. Further, it is excellent in antifouling property, has flexibility and stretchability, and can be applied to various uses requiring moisture absorption / release property and antifouling property.

Further, the manufacturing process is simple and can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of one embodiment of the moisture absorptive and desorptive sheet of the present invention. (1) …… Moisture permeable resin, (2) …… Wood powder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Anzai 1176 Uchigaike, 6th character, Inami-cho, Kako-gun, Hyogo Prefecture Toyo Tire & Rubber Co., Ltd. Hyogo Works Hyogo Factory (56) Reference Japanese Patent Laid-Open No. 61 -69456 (JP, A) JP-A-52-146481 (JP, A) JP-A-47-25262 (JP, A)

Claims (2)

[Claims] 1. A film thickness 1 measured by JIS Z-0208 B method.
A moisture absorptive and desorptive sheet in which wood powder is embedded in a moisture permeable resin layer having a moisture permeability of 0 μ film of 1000 g / m ² · 24H or more. 2. A film thickness 1 measured by JIS Z-0208 B method.
A film of 0μ has a moisture permeability of 1000g / m ² · 24H or more, and a solution or emulsion of a moisture-permeable synthetic resin and wood flour are uniformly mixed,
The method for producing a moisture absorptive and desorptive sheet according to claim 1, wherein the obtained compound is uniformly applied to the surface of a substrate, dried by heating, and then peeled from the substrate to form a sheet.