JP6657719B2 - Foam wallpaper and wall material - Google Patents

Description

  The present invention relates to a foamed wallpaper for sticking to a gypsum board having a formaldehyde adsorption function, and a wall material.

In recent years, against the background of soaring timber prices due to the depletion of natural timber, and increasing forest conservation activities related to global environmental problems, as a material with less waste of resources and less expensive than so-called solid wood of natural wood, for example, plywood, Various wood-based substrates obtained by artificially processing natural wood, such as glued laminated wood, particle board, hard board, and medium density fiber plate (MDF), have been increasingly used. .
Materials that can be said to be artificial wood have high uniformity in terms of performance, are stable in dimensional accuracy and strength, and are excellent in workability. It can be said that it has been supported.

  Such a wood-based material is produced by cutting or decomposing wood once into a thin plate, a small piece, or a fibrous shape, and joining the pieces with an adhesive to reconfigure. Therefore, it is attractive that the price is relatively low and stable. Further, as the adhesive, an adhesive containing formaldehyde such as urea-based or phenol-based is often used from the viewpoints of bonding strength to wood fiber, bonding workability, and price.

  However, in actual production, in many cases, excessive use of formaldehyde is used for the purpose of improving the bonding strength and bonding speed, and formaldehyde is volatilized from the adhesive by heat treatment for curing the adhesive. In some cases, formaldehyde remains in the wood-based material in some cases because it remains in wood fibers and wood chips.

  Building materials and furniture manufactured in this way are considered to be harmful to the human body and formaldehyde gas, which has a peculiar unpleasant odor called formalin odor, is dissipated. In addition, it has been pointed out that allergic symptoms and other health hazards may occur. Formaldehyde is one of the causes of a phenomenon called sick house syndrome, which has attracted attention in recent years.

As a solution to this problem, for example, in Japanese Patent Application Laid-Open No. H10-157, the wood grain is printed on paper impregnated with a formaldehyde adsorbent, and is attached to the surface of the wood-based base material, thereby adsorbing and removing formaldehyde diffused from the wood-based base material. Although a method has been proposed, it has been used only for decorative plywood.
Alternatively, Patent Document 2 proposes to provide a resin layer containing a formaldehyde adsorbent on a base sheet, but the design is limited and its effect is limited to the area where the surface resin layer is in contact. Was.
Under these circumstances, there is a need for interior materials capable of efficiently adsorbing formaldehyde without impairing the design properties and surface properties, and in particular, wallpaper that can be used in large areas such as walls and ceilings. Was.

Japanese Patent Publication No. 52-134 JP-A-10-258495

  The present invention has been made in view of the above points, and an object of the present invention is to provide a foamed wallpaper capable of effectively adsorbing formaldehyde in the atmosphere to a gypsum board having a formaldehyde adhesive function.

In order to solve the problem, a foamed wallpaper of one embodiment of the present invention is a foamed wallpaper stuck to a gypsum board having a formaldehyde adsorption function, and a foamed resin layer and a surface layer are formed in this order on a base sheet. A plurality of small holes having a depth from the surface layer to an intermediate position in the thickness direction of the foamed resin layer, and a moisture permeability of the entire wallpaper being 500 g / m ² · day or more and 1500 g / m ² · day or less. It is characterized by.
The surface layer is, for example, any one of a coat layer, a picture layer, and a surface protective layer, or a combination thereof.

According to the aspect of the present invention, by limiting the moisture permeability of the foamed wallpaper to the above range, it is possible to effectively adsorb formaldehyde in the atmosphere to the gypsum board.
The small holes having a depth up to a position in the thickness direction of the foamed resin layer enable the wallpaper to have a predetermined stain resistance while securing the moisture permeability in the above range.
Further, since it is not necessary to include a formaldehyde adsorbent in the foamed wallpaper itself, it is possible to prevent the design and surface properties of the wallpaper from being impaired by including the formaldehyde adsorbent.

It is an example of the foaming wallpaper which concerns on embodiment based on this invention, Comprising: It is the partial cross-section schematic diagram of the state bonded together on the gypsum board which is a base material board.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the foamed wallpaper 10 of the present embodiment has a foamed resin layer 2 formed on a base sheet 1, and a coat layer 3, a picture layer 4, and a surface protection layer 5 provided in this order. I have. The coat layer 3, the pattern layer 4, and the surface protection layer 5 form a surface layer. If the surface layer is not necessary, any one or more of the coat layer 3, the picture layer 4, and the surface protective layer 5 can be omitted.
Further, in the present embodiment, a case where a three-dimensional design property is imparted to the wallpaper 10 by exemplifying heating and foaming after providing a surface layer on the foamed resin layer 2 and embossing from the surface to impart irregularities is illustrated. ing.
Here, FIG. 1 illustrates a state in which the foamed resin layer 2 is bonded to a gypsum board as a base plate via an adhesive layer 11.

<Small hole>
The wallpaper 10 has a number of small holes 7. Each of the small holes 7 is a hole having a depth from the surface of the foamed wallpaper 10 to an intermediate position in the thickness direction of the foamed resin layer 2. The depth of the small holes 7 is, for example, in the range of 50% to 90% of the thickness of the foamed resin layer 2.
The small holes 7 are provided, for example, in a number of 4 to 12 per 1 cm ² , and each small hole 7 has an opening area at the surface layer having a diameter of 100 μm or more and 1000 μm or less, preferably 200 μm or more and 500 μm or less. Has been adjusted as follows. When the cross-sectional shape of the small hole 7 is not circular, the value is converted into the area of a circle.

The small hole 7 is formed by piercing a needle, for example. As the needle to be used, a needle having a diameter of 100 μm or more and 1000 μm or less may be used. The small hole 7 opened by the needle usually has the largest opening on the surface of the wallpaper, and the opening cross section tends to become smaller toward the tip, as shown in FIG. 1 which is a schematic diagram. For this reason, the small hole 7 is defined by the opening area at the surface layer position estimated to be substantially equal to the diameter of the needle.
By adjusting the amount per unit area of the plurality of small holes, the opening area of the small holes, and the middle position in the thickness direction of the foamed resin layer 2, the moisture permeability of the entire wallpaper is 500 g / m ² · day to 1500 g. / M ² · day or less.

By setting the moisture permeability to 500 g / m ² · day or more, formaldehyde can be applied to a gypsum board having a formaldehyde adsorption function. In addition, it was confirmed that the wallpaper could have a predetermined stain resistance if it was 1500 g / m ² · day or less.
Here, the moisture permeability in the present specification is a value calculated by measurement at a temperature of 40 ° C. and a humidity of 90% in accordance with JIS Z 0208 “Testing method for moisture permeability of moisture-proof packaging material (cup method)”.

<Base sheet>
As the base sheet 1, a paper base paper can be used in addition to a general paper base. Wallpaper base paper is not particularly limited, may be suitably selected from those sold as wallpaper base paper from paper manufacturers, it can be used as the basis weight of ^{30g / m 2 ~150g / m 2} .

<Foam resin layer>
As the resin used for the foamed resin layer 2, a vinyl chloride resin, an ethylene-vinyl acetate copolymer (EVA) resin, an acrylic resin, a polyolefin resin, or the like can be used. For forming the resin layer, a suitable method can be selected from a coating method, a method using an extruder, a method using a calendar machine, and the like.
If a resin used in the foamed resin layer 2 is, for example, an emulsion-type resin such as vinyl chloride sol, acrylic, or ethylene-vinyl acetate copolymer, it may be coated using a coating machine such as a die coater or a comma coater. It is possible.
In recent years, voices of concern about the impact on the global environment are increasing, but when considering them, it is necessary to use ethylene vinyl acetate copolymer resin, acrylic resin, polyolefin resin, etc. other than vinyl chloride resin. desirable.

  As a foaming agent contained in the foamed resin layer 2, a known foaming agent may be employed, but a pyrolytic foaming agent is preferably used. For example, azodicarbonamide (ADCA) -based foaming agents, oxybisbenzenesulfonylhydrazide (OBSH) -based foaming agents, and the like can be exemplified. Among these, ADCA-based foaming agents are preferable because they have a high thermal decomposition temperature and thus have high film-forming properties, and are less likely to abnormally foam during extrusion film-forming.

The content of the pyrolytic foaming agent can be appropriately set according to the type of the foaming agent, the expansion ratio, and the like. The blowing agent is preferably used in an amount of about 0.01 to 20 parts by weight, more preferably about 0.1 to 10 parts by weight, based on 100 parts by weight of the resin component.
The foaming agent foams by heating the wallpaper 10 to form voids in the foamed resin layer 2.
Various additives may be added to the foamed resin layer 2. For example, antioxidants, inorganic fillers, pigments and foam stabilizers, zinc compounds, crosslinking agents, surface treatment agents, fluorescent brighteners, fungicides, lubricants, and the like can be used as additives.

<Surface>
If necessary, a picture layer 4 can be provided on the surface of the foamed resin layer 2 for the purpose of improving the design. The picture layer 4 can be provided by a known printing method, and although not particularly limited, for example, a gravure printing method can be used.
The printing is performed after forming the foamed resin layer 2 and providing the coat layer 3 and the surface protection layer 5 as necessary in addition to the picture layer 4 and before heating and foaming. The ink used for printing is not particularly limited, but can be appropriately selected in accordance with the printing method and in consideration of ink adhesion, light resistance, and the like.

The coat layer 3 is provided for the purpose of strengthening the adhesiveness of the ink between the foamed resin layer 2 and the picture layer 4 or for the purpose of strengthening the adhesiveness between the foamed resin layer 2 and the surface protective layer 5. Therefore, when it is not necessary to provide the picture layer 4 and the surface protection layer 5, they may be omitted.
The surface protective layer 5 is provided for the purpose of protecting the wallpaper surface, for example, for improving the stain resistance. However, an appropriate material may be used depending on the required quality. For example, when the purpose is to improve the peel resistance, the surface hardness, or the like. In this case, the type of the coating agent can be appropriately selected according to the purpose, and the composition can be designed.

<Cosmetic materials>
The decorative material is formed by attaching the foamed wallpaper 10 having the above configuration to a gypsum board 12 having a formaldehyde adsorption function via an adhesive layer 11.
A known means may be applied to the gypsum board to impart the formaldehyde adsorption function.

<Action and others>
Formaldehyde 6 in the surrounding atmosphere effectively penetrates into the foamed resin layer 2 through the small holes 7, and further, because the foamed wallpaper 10 has a predetermined or higher moisture permeability, penetrates into the foamed resin layer 2 through the small holes 7. The formed formaldehyde 6 is effectively diffused into the foamed resin layer 2. Further, as shown by arrows in FIG. 1, the formaldehyde 6 that has entered through the small holes 7 penetrates through the base material sheet 1 and the adhesive layer 11 and reaches the gypsum board 12 as the base material plate.
Then, formaldehyde is captured and adsorbed on the gypsum board 12 having a formaldehyde adhesive function.

Here, when only the incorporation of formaldehyde into the foamed resin layer 2 is considered, there is no problem even if the moisture permeability is high, but if the moisture permeability is high, there is a possibility that contamination resistance such as weather resistance may be affected. From this viewpoint, the moisture permeability is suppressed to 1500 g / m ² · day or less.
In addition, if the diameter of the small hole 7 is large, the air permeability increases, and the efficiency of trapping and adsorbing formaldehyde increases. However, it is also important not to impair the design, and in consideration of the range that does not impair the stain resistance of the surface, the opening in the surface layer of the small hole 7 is preferably in the range of 100 μm to 1000 μm in diameter, and 200 μm to 500 μm in diameter. The following ranges are more preferable.
If the number per unit area is too large, the small holes come too close to each other, which is similar to the case where the diameter of the small holes 7 is increased. Therefore, the number of the small holes 7 is, for example, 4 per cm ^2. Numbers from 12 to 12 are preferred.

In this way, by limiting the moisture permeability of the foamed wallpaper to the above range, it becomes possible to effectively adsorb formaldehyde in the atmosphere to the gypsum board 12. The small holes having a depth up to a position in the thickness direction of the foamed resin layer enable the wallpaper to have a predetermined stain resistance while securing the moisture permeability in the above range.
Further, since it is not necessary to include a formaldehyde adsorbent in the foamed wallpaper itself, it is possible to prevent the design and surface properties of the wallpaper from being impaired by including the formaldehyde adsorbent.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
<Sample 1>
Sample 1 was prepared according to the following material composition and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Then, using a needle having a diameter of 300 μm from the picture layer side, a density of 6 pieces / cm ² up to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper is about 100 g / m ² · day. The foamed wallpaper of Sample 1 was obtained.

<Sample 2>
Sample 2 was prepared according to the following material configuration and procedure.
Laminating E VA foaming resin on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, it was heated foam.
Subsequently , a needle having a diameter of 300 μm is used from the picture layer side to a density of 6 pieces / cm ² up to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper is about 300 g / m ² · day. And a foamed wallpaper of Sample 2 was obtained.

<Sample 3>
Sample 3 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Subsequently , using a needle having a diameter of 300 μm from the picture layer side, a density of 1.5 pieces / cm is increased to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper becomes about 800 g / m ² · day. A 1 cm ² needle hole was opened to obtain a foamed wallpaper of Sample 3.

<Sample 4>
Sample 4 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Subsequently , a needle having a diameter of 300 μm is used from the picture layer side to a density of 6 pieces / 1 cm ² up to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper is about 1500 g / m ² · day. And a foamed wallpaper was obtained.

<Sample 5>
Sample 5 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Then, using a needle having a diameter of 300 μm from the picture layer side, the density is 12 pieces / cm ^{2 to} about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper is about 3000 g / m ² · day. And a foamed wallpaper of Sample 5 was obtained.

<Sample 6>
Sample 6 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Subsequently , using a needle having a diameter of 10 μm from the picture layer side, a density of 1.5 pieces / cm is increased to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper becomes about 800 g / m ² · day. A 1 cm ² needle hole was made to obtain a foamed wallpaper of Sample 6.

<Sample 7>
Sample 7 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Subsequently , using a needle having a diameter of 300 μm from the picture layer side, a density of 1.5 pieces / cm is increased to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper becomes about 800 g / m ² · day. A 1 cm ² needle hole was made to obtain a foamed wallpaper of Sample 7.

<Sample 8>
Sample 8 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Then, using a needle having a diameter of 1500 μm from the picture layer side, a density of 1.5 pieces / cm to about 80% of the thickness of the foamed resin layer so that the moisture permeability of the entire foamed wallpaper is about 800 g / m ² · day. A 1 cm ² needle hole was opened to obtain a foamed wallpaper of Sample 8.

<Sample 9>
Sample 9 was prepared according to the following material configuration and procedure.
The foamed resin laminated on the substrate sheet WK685 (KJ manufactured by Tokushu Paper), thereon a pattern layer of textured tone provided, was heated foam.
Subsequently , using a needle having a diameter of 300 μm from the picture layer side, a small hole having a density of 1.5 pieces / 1 cm ² is reached so that the moisture permeability of the entire foamed wallpaper becomes about 800 g / m ² · day. To obtain a foamed wallpaper of Sample 9.
The foamed wallpapers of Samples 1 to 9 were evaluated according to the following test items, evaluation methods, and evaluation criteria.

<Formaldehyde adsorption test>
The evaluation method is as follows.
Here, each sample of 15 cm × 15 cm was stuck on a gypsum board having a formaldehyde adsorption function to obtain a sample for evaluation.
(1) Placing an unglazed plate with a hole in the constricted part of a desiccator (inner diameter 24 cm) having a volume of 1.6 l.
(2) A glass container containing 300 ml of distilled water is placed under the unglazed plate.
(3) A sample for evaluation is placed on the unglazed plate, and a polyethylene container containing a formaldehyde generation source (solution) is placed thereon.
At this time, the concentration of the formaldehyde generation source was 0.38 mg / ml, and the solution volume was 25 ml.
(4) Collect distilled water after 24 hours.
(5) The formaldehyde concentration of distilled water is measured according to the method of JIS A6921. Here, the amount of distilled water collected from the desiccator containing only the formaldehyde generation source is 1.5 mg / ml.
The concentration of distilled water collected from the desiccator containing the sample was measured and evaluated according to the following evaluation criteria.
The evaluation criteria are as follows.
0.0-0.2 mg / ml: ○
0.3-0.5mg / ml: △
0.6-1.5 mg / ml: ×
And

<Stain resistance test>
The evaluation method is as follows.
1) The standard was established with reference to the standard "Performance of anti-fouling wallpaper" established by the Council of Wall and Barbers.
2) A4 size test piece is collected from each sample, and the following contaminants are applied to the test piece.
Coating materials: water-based felt-tip pens, crayons, coffee, soy sauce.
3) After leaving it to stand for 24 hours, wipe off the coffee / soy sauce with water and the aqueous felt-tip crayon with water or a neutral detergent.
4) Visually compare the contaminated part and the uncontaminated part.
The evaluation criteria are as follows.
Dirt comes off ： ○
Does not remove dirt: ×

<Construction test>
The evaluation method is as follows.
A sample of the same size is stuck on a 150 mm square gypsum board with construction glue.
Visually observe the absence of glue after construction.
The evaluation criteria are as follows.
No glue from small holes: ○
There is glue loss from small holes: ×
And

<Evaluation results>
Table 1 shows the evaluation results.

Samples 3 to 5 and 7 to 9 show that the formaldehyde adsorption is improved by setting the moisture permeability of the foamed resin layer to 800 g / m ² · day or more. However, even if the moisture permeability is set to 800 g / m ² · day as in sample 6, if the openings of the small holes are too small, the air permeability to the foamed resin layer is not ensured. Therefore, it is preferable that the small holes have a diameter of 100 μm or more.
Here, it was confirmed that even when a needle having a diameter of 100 μm was used and the moisture permeability was set to 500 g / m ² · day in the configuration of Sample 3, the formaldehyde adsorption on the gypsum board was good.
Further, when the moisture permeability is 3000 g / m ² · day as in sample 5, the workability is evaluated as ×, and when the moisture permeability is 1500 g / m ² · day as in sample 4, the workability is evaluated as Δ. Thus, from the viewpoint of workability, the moisture permeability is preferably 1500 g / m ² · day or less.

On the other hand, when the diameter of the needle to be used is 1500 μm as in the case of Sample 8, the result is evaluated as x in the stain resistance test. Further, even when the needle has a diameter of 300 μm as in sample 9, even when the small hole is penetrated to the base material sheet, the evaluation is x in the contamination resistance test. For this reason, it is preferable that the depth of the small holes is limited to a position in the middle of the foamed resin layer, and the diameter of the small holes is 1000 μm or less. Here, it has been confirmed that even when a needle having a diameter of 1000 μm is used in the configuration of Sample 3, the result is evaluated as “○” in the stain resistance test.
From the above results, that the depth of the small hole and to the foamed resin layer, the moisture permeability of the foamed resin layer was ^{500g / m 2 · day~1500g / m} 2 · day, and 100μm~1000μm the diameter of small holes It was found that the formaldehyde adsorption performance, the stain resistance performance, and the workability of the gypsum board were all good.

DESCRIPTION OF SYMBOLS 1 ... Base sheet 2 ... Foamed resin layer 3 ... Coat layer (surface layer)
4 ... Pattern layer (surface layer)
5 Surface protective layer (surface layer)
6 Formaldehyde 7 Small holes 10 Foamed wallpaper 11 Adhesive layer 12 Gypsum board (base plate)

Claims (7)

It is a foam wallpaper to be pasted on a gypsum board having a formaldehyde adsorption function,
A foamed resin layer and a surface layer are formed in this order on the base sheet,
A plurality of small holes of depth from the surface layer to a thickness direction intermediate position of the foamed resin layer, Ri moisture permeability 500g ^/ m 2 · day or more 1500g ^/ m 2 · day der following whole picture,
The small hole opening in the surface layer, foam wallpaper, wherein Rukoto der within the scope of the following more in diameter 100 [mu] m 1000 .mu.m. It said surface layer, undercoat layer, picture layer, and foam wallpaper according to claim 1, characterized in that it comprises at least one layer of the surface protective layer. The foamed wallpaper according to claim 1, wherein an opening area of the small hole gradually decreases from the surface layer toward a thickness direction of the foamed resin layer. 4. The small hole is 1cm ² The foamed wallpaper according to any one of claims 1 to 3, wherein the foamed wallpaper is provided within a range of 4 or more and 12 or less. The foamed wallpaper according to any one of claims 1 to 4, wherein a depth of the small hole is in a range of 50% to 90% of a thickness of the foamed resin layer. The foamed wallpaper according to any one of claims 1 to 5, wherein an opening in the surface layer of the small hole has a diameter of 200 µm or more and 500 µm or less. A wall material comprising: the foamed wallpaper according to any one of claims 1 to 6 ; and a gypsum board having a formaldehyde adsorption function to which the foamed wallpaper is attached.

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