JP6733171B2 - Foam wallpaper - Google Patents

Description

The present invention relates to wallpaper. Particularly, it relates to a foamed wallpaper having a function of adsorbing formaldehyde.

In recent years, due to the soaring price of timber due to depletion of natural timber and the rise in forest protection activities related to global environmental problems, as a less expensive material with less waste of resources than so-called solid wood of natural timber, for example, plywood, Various wood-based materials obtained by artificially processing natural wood, such as laminated wood, particle board, hard board, and medium density fiber board (MDF), have been used more than ever before. ..
Such materials that can be called artificial wood are highly uniform in terms of performance, stable in dimensional accuracy and strength, and have excellent workability. Therefore, for example, industrial production of houses such as prefabricated houses is possible. It can be said that it has supported.

Such a wood-based substrate is made by once cutting or decomposing wood into a thin plate shape, a small piece shape, or a fibrous shape, and connecting the pieces together with an adhesive to reconstitute. Therefore, it is attractive that the price is relatively cheap and stable. Further, as the adhesive, an adhesive containing formaldehyde such as urea or phenol is often used from the viewpoints of adhesive strength to wood fibers, workability of adhesion, and price.
However, in actual production, formaldehyde is often added and used for the purpose of improving the adhesive strength and the adhesive speed, and in addition, the heat treatment for curing the adhesive causes the formaldehyde to volatilize from the adhesive. In some cases, residual formaldehyde remains on the wood-based base material in some cases because it may remain in the wood fiber or wood chips, which is the actual situation.

Formaldehyde gas, which is said to be harmful to the human body and has a peculiar unpleasant odor called formalin odor, is emitted from the building members and furniture produced in this way, which causes discomfort to residents of the house and furniture users. It has been pointed out that not only the allergic symptoms but also health hazards may occur. Formaldehyde is one of the causes of the phenomenon called sick house syndrome, which has been attracting attention in recent years.
As a solution to this problem, for example, in Patent Document 1, by printing a wood grain on a paper impregnated with a formaldehyde adsorbent and pasting it on the surface of a wood-based substrate, the formaldehyde diffused from the wood-based substrate is adsorbed and removed. Although a method has been proposed, it has been used only as a decorative plywood.

Alternatively, Patent Document 2 proposes that a resin layer containing a formaldehyde adsorbent is provided on a base sheet, but its designability is limited and its effect is limited to the range in which the surface resin layer contacts. It was
Under such circumstances, interior materials that can efficiently adsorb formaldehyde without impairing the design and surface properties, especially wallpaper that can be used in large areas such as wall surfaces and ceiling surfaces have been demanded. It was

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

The present invention has been made in view of the above points, and an object thereof is to provide a foamed wallpaper that can effectively adsorb formaldehyde in the atmosphere.

In order to solve the problem, the foamed wallpaper of one embodiment of the present invention has a foamed resin layer and a surface layer formed in this order on a base sheet, and the base sheet contains a formaldehyde adsorbent, It has a plurality of small holes having a depth up to an intermediate position of the foamed resin layer.
The surface layer is, for example, any one of a coat layer, a pattern layer, and a surface protection layer, or a combination thereof.

According to the aspects of the present invention, it becomes possible to provide a foamed wallpaper having a predetermined stain resistance while effectively adsorbing formaldehyde in the atmosphere.
Further, since the formaldehyde adsorbent is provided on the back surface side of the foam wallpaper, formaldehyde can be absorbed from the base material to which the foam wallpaper is attached.

It is an example of the foaming wallpaper which concerns on embodiment based on this invention, Comprising: It is a partial cross-sectional schematic diagram of the state pasted on the base material plate.

Embodiments of the present invention will be described below 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 material sheet 1, and a coat layer 3, a pattern layer 4, and a surface protective layer 5 provided in this order. There is. The coat layer 3, the pattern layer 4, and the surface protective layer 5 form a surface layer. The surface layer may be formed by omitting any one of the coat layer 3, the pattern layer 4, and the surface protective layer 5 or a plurality of layers, if not necessary.
In addition, in the present embodiment, the case where the three-dimensional design property is given to the wallpaper 10 by providing the foamed resin layer 2 with a surface layer, followed by heat-foaming, and embossing from the surface to give unevenness is illustrated. ing.

Here, FIG. 1 exemplifies a state in which the foamed resin layer 2 is bonded to a gypsum board which is the base material plate 12 via the adhesive layer 11. The base material plate 12 to which the foamed wallpaper 10 is attached is obtained by artificially processing natural wood such as plywood, laminated wood, particle board, hard board, and medium density fiber plate (MDF) other than gypsum board. Various types of wood-based substrates can be used as the substrate plate. It is also possible to directly attach it to the wall surface or ceiling surface at the construction site. The gypsum board may be a gypsum board having a formaldehyde adsorption function. Known means may be applied to give the gypsum board a formaldehyde adsorption function.

<Small hole>
The wallpaper 10 also has a large number of small holes 7. Each small hole 7 is a hole having a depth from the surface of the foamed wallpaper 10 to an intermediate position of the foamed resin layer 2. The depth of the small holes 7 is, for example, 50% or more and 90% or less 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 the opening area of each small hole 7 at the surface layer position is 100 μm or more and 1000 μm or less, preferably 200 μm or more and 500 μm or less. Is adjusted. When the cross-sectional shape of the small hole 7 is not circular, the value is converted to the area of a circle.

The small hole 7 is formed by puncturing 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 as shown in the schematic view of FIG. 1, and the opening cross section tends to become smaller toward the tip. For this reason, the small hole 7 is defined by the opening area at the surface layer position which is estimated to be substantially equal to the diameter of the needle.
By adjusting the amount of the plurality of small holes 7 per unit area, the opening area of the small holes 7 and the middle position in the thickness direction of the foamed resin layer ² , the moisture permeability of the foamed resin layer is 500 g/m ² ·. It is adjusted to be not less than day and not more than 1500 g/m ² ·day.

By setting the water vapor permeability to 500 g/m ² ·day or more, formaldehyde in the base material sheet 1 having a formaldehyde adsorption function can be more effectively absorbed.
Further, since the small holes 7 do not penetrate the foamed resin layer, stain resistance can be provided. In particular, it has been confirmed that the wallpaper can have a predetermined stain resistance at 1500 g/m ² ·day or less.
Here, the water vapor transmission rate in this specification is a value calculated by measurement at a temperature of 40° C. and a humidity of 90% in accordance with JIS Z 0208 “Moisture vapor transmission test method for moisture-proof packaging material (cup method)”.

<Base material sheet 1>
For the base sheet 1, not only a general paper base but also wallpaper base paper can be used. 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} .
The base sheet 1 of this embodiment contains a formaldehyde adsorbent.
For example, the formaldehyde adsorbent is contained in the base sheet 1 by applying and drying an aqueous formaldehyde adsorbent solution on the surface of the base sheet 1.

The formaldehyde adsorbent aqueous solution is an aqueous solution containing one or more organic substances selected from urea, ethylene urea, a hydrazide compound, an alcohol amine compound, an azole compound, and an azine compound as a formaldehyde adsorbent. A formaldehyde adsorbent is provided on the base material sheet 1.
The concentration of the formaldehyde adsorbent in the formaldehyde adsorbent aqueous solution is 30% by mass or more, preferably 50% by mass or more. A higher concentration improves formaldehyde adsorption.
A primer layer for adhesion may be provided between the base material sheet 1 and the foamed resin layer 2 in order to secure adhesiveness above a predetermined level. In this case, the formaldehyde adsorbent aqueous solution may be applied to the base material sheet 1 itself and the formaldehyde adsorbent may be added to the primer layer. In this case, the amount of adsorbent blended is, for example, 0.1 to 10 parts by mass of adsorbent with respect to 100 parts by mass of the primer in the primer layer.

<Foam resin layer>
The resin used for the foamed resin layer 2 may be a vinyl chloride resin, an ethylene vinyl acetate copolymer (EVA) resin, an acrylic resin, a polyolefin resin, or the like. For forming the resin layer, a suitable one can be selected from a coating method, a method using an extruder, a method using a calendar machine, and the like.
If, for example, a vinyl chloride sol, an acrylic resin, or an ethylene-vinyl acetate copolymer emulsion type resin is used as the resin used for the foamed resin layer 2, it can be applied using a coating machine such as a die coater or a comma coater. It is possible.

Recently, there are growing concerns about the impact on the global environment, but when considering them, it is preferable to use ethylene vinyl acetate copolymer resin other than vinyl chloride resin, acrylic resin, polyolefin resin, etc. desirable.
As the foaming agent contained in the foamed resin layer 2, a known foaming agent may be adopted, but a thermal decomposition type foaming agent is preferably used. For example, an azodicarbonamide (ADCA) type foaming agent, an oxybisbenzenesulfonyl hydrazide (OBSH) type foaming agent, etc. can be illustrated. Among these, the ADCA-based foaming agent is preferable because it has a high thermal decomposition temperature and thus has a high film-forming property, and there is little risk of abnormal foaming during extrusion film-forming.

The content of the thermal decomposition type foaming agent can be appropriately set according to the type of foaming agent, the expansion ratio, and the like. The foaming agent is preferably about 0.01 to 20 parts by mass, more preferably about 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin component.
The foaming agent foams when the wallpaper 10 is heated to form voids in the foamed resin layer 2.
Here, the foamed resin layer 2 may also be mixed with a formaldehyde adsorbent. The formaldehyde adsorbent to be blended must contain one or more organic substances selected from urea, ethylene urea, hydrazide compounds, alcohol amine compounds, azole compounds and azine compounds.

The formaldehyde adsorbent is contained in an amount of 0.1 to 10 parts by mass of the adsorbent with respect to 100 parts by mass of the resin of the foamed resin layer 2 so that the wallpaper production process is not hindered. Further, the effect of adsorbing formaldehyde is preferably exhibited without impairing the design and the like.
In addition, the foamed resin layer 2 may be blended with one or more inorganic substances selected from natural zeolite, acid clay, diatomaceous earth, synthetic zeolite, artificial zeolite, activated carbon, titanium oxide, and phosphate. By containing the inorganic substance, the adsorption of formaldehyde in the foamed resin layer 2 can be further promoted.

For example, since the main components of zeolite are silicon dioxide and aluminum oxide, which have a porous structure, they not only have an adsorbing function themselves, but also act to aid the adsorption of the formaldehyde adsorbent of the compounded organic compound. .. This also applies to acid clay, diatomaceous earth, activated carbon, etc., and can be appropriately selected in consideration of adsorption performance and price.
Various additives may be added to the foamed resin layer 2. For example, an antioxidant, an inorganic filler, a pigment and a foaming stabilizer, a zinc compound, a cross-linking agent, a surface treatment agent, a fluorescent brightening agent, an antifungal agent, a lubricant and the like can be used as an additive.

<Surface>
If necessary, the pattern layer 4 may be provided on the surface of the foamed resin layer 2 for the purpose of improving the design. The pattern layer 4 can be provided by a known printing method, and although not particularly limited, for example, a gravure printing method can be used.
Printing is performed after the foamed resin layer 2 is formed, and in addition to the picture layer 4, the coat layer 3 and the surface protective layer 5 are provided, if necessary, before heat foaming. The ink used for printing is not particularly limited, but can be appropriately selected according to the printing method, the ink adhesion, the light resistance, and the like.

The coat layer 3 is provided for the purpose of strengthening the ink adhesion between the foamed resin layer 2 and the pattern layer 4, or for strengthening the adhesion between the foamed resin layer 2 and the surface protective layer 5. Therefore, if it is not necessary to provide the pattern layer 4 and the surface protective layer 5, they may be omitted.
The surface protective layer 5 is provided for the purpose of protecting the wallpaper surface such as improving stain resistance, but an appropriate material may be used depending on the required quality. For example, when the purpose is to improve peeling resistance or surface hardness. The type of coating agent can be appropriately selected according to the purpose, and the composition can be designed.

<Action and others>
In the wallpaper 10, formaldehyde 6 in the surrounding atmosphere effectively penetrates into the foamed resin layer 2 through the small holes 7, and formaldehyde 6 that penetrates into the foamed resin layer 2 through the small holes 7 effectively penetrates into the foamed resin. Diffuses into layer 2.
Further, as shown by the arrow in FIG. 1, the formaldehyde 6 that has entered through the small holes 7 penetrates the foamed resin layer 2 and reaches the base sheet 1. Then, formaldehyde is captured and adsorbed by the base material sheet 1 having a formaldehyde adhesion function. In this way, formaldehyde is effectively adsorbed through the small holes 7.

Here, when only taking in formaldehyde into the base material sheet 1 is taken into consideration, there is no problem even if the foamed resin layer has a high water vapor transmission rate, but if the water vapor transmission rate becomes high, the contamination resistance such as weather resistance may be affected. There is. From this viewpoint, it is preferable to suppress the moisture permeability of the foamed resin layer to 1500 g/m ² ·day or less.
Further, the larger the diameter of the small holes 7, the higher the air permeability, and the higher the efficiency of trapping and adsorbing formaldehyde. However, it is important not to impair the design, and considering the range that does not impair the surface stain resistance, the opening of the small holes 7 in the surface layer is preferably in the range of 100 μm to 1000 μm in diameter, and 200 μm to 500 μm in diameter. The following range is more preferable.

If the number per unit area is too large, the small holes come too close to each other, and the same thing as when the diameter of the small holes 7 is increased. Therefore, the number of the small holes 7 is, for example, 4 per 1 cm ^2. A number from 1 to 12 is preferred.
As described above, in the foamed wallpaper of the present embodiment, it is possible to provide the foamed wallpaper having a predetermined stain resistance while effectively adsorbing formaldehyde in the atmosphere.
Further, since the formaldehyde adsorbent is provided on the back surface side of the foam wallpaper, formaldehyde can be absorbed from the base material to which the foam wallpaper is attached.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples.
<Sample 1>
Sample 1 was prepared with the following material configuration and procedure.
A base resin sheet 1WK685 (made of KJ special paper) was laminated with a foamed resin, and a texture-like pattern layer was provided on the foamed resin, and heat-foamed. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 6 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 1.

<Sample 2>
Sample 2 was prepared with the following material configuration and procedure.
A base material sheet 1WK685 (made by KJ special paper) was coated with a 10 mass% formaldehyde adsorbent aqueous solution, laminated with a foaming resin, and a textured pattern layer was provided on the foamed resin for foaming by heating. Subsequently, using a needle having a diameter of 300 μm from the pattern layer side, needle holes having a density of 6 pieces/1 cm ² were made up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 2.
<Sample 3>
Sample 3 was prepared with the following material configuration and procedure.
A base material sheet 1WK685 (made by KJ special paper) was coated with a 30% by mass aqueous formaldehyde adsorbent solution, laminated with a foaming resin, and a textured pattern layer was provided on the foamed resin for heat foaming. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 6 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 3.

<Sample 4>
Sample 4 was prepared with the following material configuration and procedure.
A base material sheet 1WK685 (made by KJ special paper) was coated with a 40% by weight formaldehyde adsorbent aqueous solution, laminated with a foaming resin, and a texture pattern layer was provided on the foamed resin for heat foaming. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 6 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 4.
<Sample 5>
Sample 5 was prepared with the following material configuration and procedure.
A 50% by weight formaldehyde adsorbent aqueous solution was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated thereon, and a texture pattern layer was provided on the foamed resin to heat and foam. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 6 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 5.

<Sample 6>
Sample 6 was prepared with the following material configuration and procedure.
A base material sheet 1WK685 (made by KJ special paper) was coated with a 60 mass% formaldehyde adsorbent aqueous solution, laminated with a foaming resin, and a texture pattern layer was provided on the foamed resin to heat foam. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 6 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 6.
<Sample 7>
Sample 7 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make a needle hole having a density of 1 piece/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 7.

<Sample 8>
Sample 8 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 3 pieces/1 cm ² up to about 80% of the thickness to obtain a foamed wallpaper of Sample 8.
<Sample 9>
Sample 9 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Subsequently, using a needle having a diameter of 300 μm from the pattern layer side, needle holes having a density of 6 pieces/1 cm ² were made up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 9.

<Sample 10>
Sample 10 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Then, using a needle having a diameter of 300 μm from the pattern layer side, needle holes having a density of 10 pieces/1 cm ² were made up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 10.
<Sample 11>
Sample 11 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Subsequently, using a needle having a diameter of 300 μm from the pattern layer side, needle holes having a density of 15 pieces/1 cm ² were made up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 11.

<Sample 12>
Sample 12 was prepared with the following material configuration and procedure.
A 50% by weight aqueous solution of formaldehyde adsorbent was applied onto a base sheet 1WK685 (made by KJ special paper), a foaming resin was laminated, and a texture-like pattern layer was provided on the foaming resin to heat and foam. Subsequently, a needle having a diameter of 300 μm was used from the pattern layer side to make needle holes having a density of 20 pieces/1 cm ² up to about 80% of the thickness of the foamed resin layer to obtain a foamed wallpaper of Sample 12.
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.
(1) Arrange a biscuit plate with holes in the constricted part of a desiccator (internal 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 15 cm×15 cm sample is placed on the unglazed plate, and a polyethylene container containing a formaldehyde generation source (solution) is placed on the sample.
At this time, the concentration of the formaldehyde generating source was 0.38 mg/ml, and the solution amount 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. Distilled water collected from a desiccator containing only a formaldehyde source is 1.5 mg/ml.

The concentration of distilled water collected from a desiccator containing the test piece was measured and evaluated according to the following evaluation criteria.
The evaluation criteria are as follows.
0.0-0.2 mg/ml: ○
0.3-0.5 mg/ml: △
0.6-1.5 mg/ml: ×

<Stain resistance test>
The evaluation method is as follows.
1) It was carried out with reference to the standard "Performance of anti-stain wallpaper" established by the Council of Wall Wholesalers.
2) Take an A4 size test piece and apply the following contaminants to the test piece.
Pollutants: water-based pens, crayons, coffee, soy sauce.
3) After leaving this for 24 hours,
Wipe off coffee and soy sauce with water, and water-based felt-tip pens and crayons with water or neutral detergent.
4) Visually compare the contaminated and uncontaminated areas.
The evaluation criteria are as follows.
Dirt is removed: ○
Dirt does not come off: ×

<Construction test>
The evaluation method is as follows.
A test piece of the same size is mounted on a 150 mm square gypsum board with a construction glue.
Visually observe the presence or absence of glue removal after construction.
The evaluation criteria are as follows.
No glue comes out from the through hole: ○
There is glue removal from the through hole: ×

<Coatability>
The evaluation method is as follows.
The foamed resin is applied to the base material sheet 1 using an applicator, dried, and then visually observed.
The evaluation criteria are as follows.
A uniform film can be formed: ○
Some lack of uniformity in film: △
Cannot form a uniform film: ×

<Evaluation result>
The evaluation results are shown in Table 1.

As can be seen from Samples 3 to 6 and 9 to 12, when the concentration of the adsorbent in the formaldehyde adsorbent aqueous solution provided on the surface of the base material sheet 1 is 30% by mass or more, preferably 50% by mass or more, formaldehyde adsorption It turns out that it becomes good. However, when the number of needle holes is too small as in Samples 7 and 8, the air permeability up to the base sheet 1 is not ensured.
Here, in the sample 3～6,9, although moisture permeability of the foamed resin layer is in the range of ^{500g / m 2 · day~1500g / m} 2 · day, the moisture permeability of the sample 7 and 8 foamed resin layer It was about 100 g/m ² ·day. The samples 11 and 12 had a moisture permeability of 3000 g/m ² ·day or more. In Sample 10, the water vapor transmission rate was 1500 g/m ² ·day.
In addition, since the needle holes (small holes) are in the middle of the foamed resin layer in all the samples, a predetermined stain resistance is secured.
When the number of needle holes is too large as in Samples 10 to 12, the moisture permeability becomes too high and the workability becomes poor.

From the above, it is preferable that the moisture permeability of the foamed resin layer is set to be in the range of ^{500g / m 2 · day~1500g / m} 2 · day. Note that when the moisture permeability of the base sheet is high, the moisture permeability of the entire foam wallpaper in a range of from ^{500g / m 2 · day~1500g / m} 2 · day, the moisture permeability of the foamed resin layer is 500 g / in the range of ^{m 2 · day~1500g / m 2 ·} day.
Further, if the concentration of the adsorbent in the aqueous formaldehyde adsorbent solution is too high, the coatability deteriorates, but if the concentration is 50 mass% or less, preferably 40 mass% or less, sufficient coatability is secured. You can see that it is done.

1... Substrate sheet 2... Foamed resin layer 3... Coat layer (surface layer)
4... Design layer (surface layer)
5: Surface protective layer (surface layer)
6... Formaldehyde 7... Small holes 10... Foaming wallpaper 11... Adhesive layer 12... Gypsum board (base plate)

Claims (11)

A foamed resin layer and a surface layer are formed in this order on the base material sheet,
The substrate sheet contains a formaldehyde adsorbent,
Having a plurality of small holes of a depth from the surface layer to the middle position of the foamed resin layer,
The small holes, Ri opening der following terms and diameter 20μm or more as 1000μm in a circular shape opening area at the surface layer,
The concentration of the formaldehyde adsorbent is 30% by mass or more,
The small pores, foamed wallpaper characterized that you have provided within the 1 cm ² per 4 or more 12 or less. Foam wallpaper according to claim 1, wherein the moisture permeability of the foamed resin layer is in the range of ^{500g / m 2 · day~1500g / m} 2 · day. The foamed wallpaper according to claim 1 or 2, wherein the opening area of the small holes gradually decreases from the surface layer in the thickness direction of the foamed resin layer. The one or more organic substances selected from urea, ethylene urea, a hydrazide compound, an alcohol amine compound, an azole compound, and an azine compound are contained as the formaldehyde adsorbent. The foamed wallpaper described in any one of 1. The foamed wallpaper according to any one of claims 1 to 4, wherein the surface layer is composed of at least one layer of a coat layer, a pattern layer, and a surface protective layer. The foamed resin layer contains natural zeolite, acid clay, diatomaceous earth, synthetic zeolite, artificial zeolite, activated carbon, titanium oxide, or any one or more inorganic substances of phosphate. The foamed wallpaper according to any one of claims 1 to 5. The surface layer has irregularities formed by embossing,
The said small hole penetrates the said surface layer in which the said unevenness was formed, and is formed only in the said surface layer side, The foam wallpaper as described in any one of Claims 1-6. The small pores, foamed wallpaper as set forth in any one of claims 1 to 7, characterized in that provided within the scope of 1 cm ² per 6 or more 12 or less. The foamed wallpaper according to any one of claims 1 to 8, wherein the depth of the small holes is within 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 9, wherein the small holes have a diameter within a range of 200 µm or more and 500 µm or less when the opening area in the surface layer is converted into a circular shape. .. The foamed wallpaper according to any one of claims 1 to 10, wherein the concentration of the formaldehyde adsorbent in the aqueous formaldehyde adsorbent solution provided on the surface of the substrate sheet is 30% by mass or more.

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