Foam wallpaper

Abstract

To provide foamed wall paper having an ability to conceal roughness and high surface strength.SOLUTION: Foamed wall paper is constituted by laminating: a paper substrate 2; a foamed resin layer 3 composed of a resin composition containing an aqueous emulsion-based resin, a foaming agent, and an inorganic filler; and a surface protective layer 5 containing an acrylic resin as a main constituent in this order, where the paper substrate 2 has a basis weight of within a range of 50 g / m2 or more and 100 g / m2 or less, and a thickness of 80 μm or more and 150 μm or less, the resin composition includes 50 pts.mass or more and 150 pts.mass or less of the inorganic filler to 100 pts.mass of the aqueous emulsion-based resin in a dry state, and 1 pt.mass or more and 20 pts.mass or less of the foaming agent to 100 pts.mass of the aqueous emulsion-based resin, the basis weight after drying of the foamed resin layer 3 is within a range of 120 g / m2 or more and 170 g / m2 or less, the expansion ratio is 5 times or more, and the basis weight of the surface protective layer 5 is 1 g / m2 or more and 40 g / m2 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to foam wallpaper for use as interior materials for buildings such as walls and ceilings. [Background technology]

[0002] When renovating a house, the backing paper from the previous wallpaper may remain in some places on the base. The unevenness of this base is called unevenness. In general, the ability to make unevenness less noticeable is called unevenness hiding ability.

[0003] If the surface to be installed is uneven, it requires time-consuming and labor-intensive base preparation work such as applying a sealer or repairing with putty, resulting in poor overall installation efficiency. Furthermore, in areas where wallpaper has been replaced multiple times, the unevenness of the base is likely to be very noticeable, making it necessary to carefully prepare the base. In other words, if the preparation of the base is not done properly, the unevenness of the base may be picked up when the wallpaper is installed, and the unevenness may be noticeable on the surface of the wallpaper.

[0004] For this reason, wall covering materials such as foam laminate sheets that have sufficient volume to conceal unevenness have been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-142202 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional wall coverings can absorb unevenness in the substrate by providing a sense of volume, but this has the problem of reducing surface strength. The present invention has been made to solve such problems, and an object of the present invention is to provide a foam wallpaper having unevenness hiding properties and high surface strength. [Means for solving the problem]

[0007] According to one aspect of the present invention, a paper substrate, a foamed resin layer formed from a resin composition containing an aqueous emulsion resin, a foaming agent, and an inorganic filler, and a surface protective layer mainly composed of an acrylic resin are laminated in this order, and the paper substrate has a basis weight of 50 g / m 2 More than 100g / m 2 and a thickness of 80 μm or more and 150 μm or less, the resin composition in a dry state contains the inorganic filler in a range of 50 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the aqueous emulsion resin, and contains the foaming agent in a range of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the aqueous emulsion resin, and the foamed resin layer has a basis weight after drying of 120 g / m 2 More than 170g / m 2 and the foaming ratio is 5 times or more, and the dried basis weight of the surface protective layer is 1 g / m 2 More than 40g / m 2 The following foam wallpaper is provided: [Effects of the Invention]

[0008] According to the present invention, foam wallpaper having unevenness hiding properties and high surface strength can be obtained. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view schematically showing an example of foam wallpaper according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of each thickness, etc., differ from the actual ones. Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, shapes, etc. of the components described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0011] <Configuration> 1 is a cross-sectional view showing a schematic example of foamed wallpaper 1 according to the present invention, in which a foamed resin layer 3, an optional pattern printed layer 4, and a surface protective layer 5 are laminated in this order on one side of a paper substrate 2 serving as a base material. Furthermore, an embossed pattern 6 is formed on the surface of foamed wallpaper 1 facing the surface protective layer 5.

[0012] <Paper base material> The paper substrate 2 is a so-called wallpaper backing paper (fibrous sheet). 2 More than 100g / m 2 The general wallpaper paper having a thickness of 80 μm or more and 150 μm or less can be used. By using such general wallpaper paper, the rigidity required for use as a wall covering can be ensured.

[0013] <Foamed resin layer> The foamed resin layer 3 is formed by applying a resin composition containing a foaming agent (hereinafter referred to as a foaming agent-containing resin composition) to the surface of the paper substrate 2, and then heating and foaming the foaming agent contained in the applied foaming agent-containing resin composition. The foaming agent-containing resin composition is an appropriate mixture of an aqueous emulsion resin, a foaming agent, and an inorganic filler as a filler. The foamed resin layer 3 has a basis weight of 120 g / m after drying. 2 More than 170g / m 2 The expansion ratio of the foamed resin layer 3 is preferably 5 times or more and 7 times or less from the viewpoint of unevenness hiding ability and quasi-nonflammability.

[0014] The foaming agent-containing resin composition may further contain other additives such as colorants. The foaming ratio is expressed as the value of (thickness of resin before foaming) / (thickness of resin after foaming). The thickness of the foamed resin here refers to the thickness after foaming and before the embossing process described below is applied.

[0015] As the aqueous emulsion resin, a resin that can be used in the form of an aqueous emulsion, such as a polyolefin resin, can be used. In particular, at least one ethylene copolymer containing ethylene and a component other than ethylene as monomers is more preferred.

[0016] The foaming agent used is a thermally expandable microcapsule foaming agent. While foaming agents commonly used in foam wallpapers can be used, thermally expandable microcapsule foaming agents are preferred from the standpoint of performance (expansion ratio, strength). Other foaming agents that can be used include azo-based, hydrazide-based, and nitroso-based foaming agents.

[0017] The foaming agent is added in an amount of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the aqueous emulsion resin. Examples of inorganic fillers contained in the foaming agent-containing resin composition include calcium carbonate, aluminum hydroxide, magnesium hydroxide, silica sand, talc, silicas, magnesium silicate, zinc borate, and titanium dioxide.

[0018] The inorganic filler is added in an amount of 50 parts to 150 parts by mass relative to 100 parts by mass of the aqueous emulsion resin. The foaming agent-containing resin composition can be applied in the form of a paste by a coating method such as knife coating, nozzle coating, die coating, lip coating, comma coating, gravure coating, rotary screen coating, or reverse roll coating.

[0019] <Picture printing layer> The picture printed layer 4 is intended to impart design features such as a picture pattern to the foamed wallpaper 1. The picture printed layer 4 may be provided as needed. The thickness of the pattern printed layer 4 varies depending on the pattern, but is generally preferably about 0.1 μm or more and 10 μm or less.

[0020] The picture printed layer 4 is formed by gravure printing, screen printing, flexographic printing, ink jet printing, etc. using a printing ink (non-foaming ink), a foaming ink mainly composed of an aqueous emulsion resin, a foaming ink mainly composed of a vinyl chloride paste resin, etc. The picture printed layer 4 is printed before the foaming agent in the foaming agent-containing resin composition that will become the foamed resin layer 3 is foamed.

[0021] <Surface protective layer> The surface protection layer 5 is formed by applying a resin containing an acrylic resin as a main component onto the picture print layer 4. The surface protection layer 5 is formed on the surface of the pattern print layer 4 to adjust the gloss and protect the pattern print layer 4. In addition, it has the function of preventing the wallpaper from expanding when a water-based adhesive (glue) is applied during construction, and also prevents shrinkage that occurs as the wallpaper dries.

[0022] In order to achieve this function, the main component must be acrylic resin. The surface protective layer 5 has a basis weight of 1 g / m 2 More than 40g / m 2 The following is the result. A filler (such as silica) may be added to the surface protective layer 5 for the purpose of adjusting the gloss. Alternatively, the surface protection layer 5 may be made of an acrylic resin as the main component and a silicone resin added thereto.

[0023] The surface protection layer 5 is formed by applying a resin whose main component is acrylic resin onto the pattern printing layer 4, or, if the pattern printing layer 4 is not provided, onto the foaming agent-containing resin composition that will become the foamed resin layer 3, and then heating and drying it. The resin mainly composed of acrylic resin that will become the surface protective layer 5 can be applied to the surface of the pattern printed layer 4 or the foaming agent-containing resin composition by gravure printing, knife coating, nozzle coating, die coating, lip coating, comma coating, etc.

[0024] As described above, the foaming agent-containing resin composition that will become the foamed resin layer 3, the picture printed layer 4, and the surface protective layer 5 are laminated on the paper base material 2, and then the foamed resin layer 3 is heated to foam, and immediately after foaming, embossed from the surface protective layer 5 side. Embossing may be performed as needed.

[0025] Embossing is carried out simultaneously with or immediately after heat foaming. The surface temperature of the foamed wallpaper just before contact with the embossing plate in the embossing process is preferably 160°C or higher and 200°C or lower. In order to impart fire retardancy, the total basis weight of the paper substrate 2, foamed resin layer 3, and surface protective layer 5 after drying is 240 g / m 2 It is preferable that:

[0026] <Effects> The foamed wallpaper 1 according to this embodiment can easily absorb unevenness in the uneven parts of the base by increasing the thickness of the foamed resin layer, thereby making the unevenness less noticeable. Furthermore, when the foamed resin layer is foamed, its thickness increases, weakening its strength and reducing its surface strength. The foamed wallpaper 1 according to this embodiment has a resin coating formed on the surface of the foamed resin layer as a surface protective layer, which prevents the surface strength of the foamed resin layer from decreasing. In particular, the use of an aqueous emulsion primarily composed of acrylic as the surface protective layer not only protects the surface of the picture-printed layer 4, but also prevents the foamed wallpaper 1 itself from expanding or shrinking. [Example]

[0027] Examples and comparative examples of this embodiment are shown below, but this embodiment is not limited to the following. <Example> As the paper base material 2, paper containing only natural pulp and no synthetic resin ("WK665TMN" manufactured by KJ Specialty Paper Co., Ltd.) was used. The basis weight was 65 g / m 2 is. As the aqueous emulsion resin, ethylene-vinyl acetate copolymer (Sumika Chemtex Corporation's "S-7400 (HQ)") and a mixture of ethylene-vinyl acetate copolymer and acrylic (Japan Coating Resin Co., Ltd.'s "FK-715") were used. 80 parts of the ethylene-vinyl acetate copolymer (Sumika Chemtex Corporation's "S-7400 (HQ)") were mixed with 20 parts by mass of the mixture of ethylene-vinyl acetate copolymer and acrylic (Japan Coating Resin Co., Ltd.'s "FK-715"), 10 parts by mass of a thermally expandable microcapsule blowing agent (Matsumoto Yushi Pharmaceutical Co., Ltd.'s "FT-16"), and 80 parts by mass of calcium carbonate powder (Asahi Komatsu Co., Ltd.'s "MC-100") as an inorganic filler to produce a paste-like blowing agent-containing resin. This was applied to the paper substrate 2 to form a layer of the blowing agent-containing resin composition that would become the foamed resin layer 3.

[0028] On the foamed resin layer (layer of a foaming agent-containing resin composition) 3, a picture printed layer 4 was formed by gravure printing using a printing ink containing an acrylic resin as the resin component. The basis weight of the picture printed layer 4 after drying is 8 g / m 2 is.

[0029] A surface protective layer 5 was formed on the picture print layer 4 by gravure printing using a paint containing acrylic resin as the main component ("ATC-354" manufactured by DIC Corporation). The surface protective layer 5 had a basis weight of 20 g / m2 after drying. 2 is.

[0030] Finally, the layer of the foaming agent-containing resin composition was foamed by heating to form a foamed resin layer 3, and immediately thereafter, an embossing process was carried out from the surface protective layer 5 side using an embossing roll to form an embossed pattern, thereby producing foamed wallpaper.

[0031] Example 1 The foamed resin layer 3 has a post-drying mass of 120 g / m2 (Expansion ratio 5 times). Example 2 The foamed resin layer 3 has a post-drying mass of 170 g / m 2 (Expansion ratio 7 times).

[0032] <Comparative Example> In the foamed wallpaper in the <Example>, foamed wallpaper was produced using the same materials and procedures, except that the surface protective layer 5 was not provided and the mass of the foamed resin layer after drying was changed.

[0033] (Comparative Example 1) The foamed resin layer 3 has a post-drying mass of 120 g / m 2 (Expansion ratio 5 times). (Comparative Example 2) The foamed resin layer 3 has a post-drying mass of 100 g / m 2 (Expansion ratio 4 times). (Comparative Example 3) The foamed resin layer 3 has a post-drying mass of 190 g / m 2 (Expansion ratio 8 times).

[0034] <Evaluation method and criteria> The foamed wallpapers of the Examples and Comparative Examples were evaluated by the following methods. (1) Concealment of unevenness To evaluate the ability to conceal unevenness, a circular sticker 100 μm thick and 20 mm in diameter was attached to a plasterboard (9.5 mm thick) that met the semi-fireproof standard, and foam wallpaper was attached on top of that with glue. Light was shone on it from the side to evaluate whether or not uneven areas (places that were not level) could be identified visually. Evaluations were made for both the case where one circular sticker was attached and the case where two circular stickers were attached on top of each other. The amount of glue applied when attaching the circular sticker to the plasterboard was 20 g / m. 2 (solid content). The evaluation criteria are as follows: ○ (Pass): Unable to identify unevenness. × (Fail): Unevenness can be identified.

[0035] (2) Surface strength To evaluate the surface strength, a test was conducted in accordance with the standard "Surface Strengthened Wallpaper Performance Standards" established by the Wallpaper Industry Association, in which the state of damage to the surface when scratched was visually determined and it was evaluated whether the base paper layer (paper substrate 2) was exposed. The evaluation criteria are as follows: ○ (pass): The base paper layer is not exposed. × (fail): The base paper layer is exposed.

[0036] (3) Semi-nonflammable To evaluate the non-combustibility of foamed wallpaper, a cone calorimeter C3 (a combustion tester manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to test the heat release rate of semi-non-combustible materials (50 kW / m) based on the heat release test method (ISO 5660) specified in the Building Standards Act. 2 Heating at 400 K for 10 minutes was carried out. The evaluation criteria are as follows: ○: Burned calories are 7.2MJ or less. ×: Burned calories are greater than 7.2MJ.

[0037] <Evaluation results> The evaluation results are shown in Table 1 below.

[0038] [Table 1]

[0039] From Table 1, it was confirmed that the foam wallpapers of Examples 1 and 2 satisfied all of the requirements for unevenness hiding ability, surface strength, and semi-non-flammability.

[0040] By comparing Example 1 with Comparative Examples 1 and 2, it was confirmed that increasing the amount of foamed resin layer applied improves unevenness concealment, but reduces surface strength, and in that case, surface strength can be obtained by providing a surface protection layer on the foamed resin layer. Furthermore, if the amount of foamed resin layer applied is small, unevenness concealment (Comparative Example 2) is not obtained, and if the amount of foamed resin layer applied is large, quasi-nonflammability decreases (Comparative Example 3). Furthermore, in order to satisfy all of unevenness concealment, surface strength, and quasi-nonflammability, the amount of foamed resin layer applied must be 120 g / m 2 More than 170g / m 2 The value is preferably within the following range. If the amount of foamed resin layer applied is too large, the quasi-nonflammable property decreases. Therefore, the amount of foamed resin layer applied is set to 170 g / m. 2 Hereinafter, it was confirmed that the expansion ratio is preferably 7 times or less (Example 2).

[0041] The above describes the embodiments and examples of the present invention, but the foam wallpaper 1 of the present invention is not limited to the above embodiments and examples, and various modifications are possible within the scope that does not impair the characteristics of the invention. [Explanation of symbols]

[0042] 1. Foam wallpaper 2 Paper base material 3. Foamed resin layer 4. Picture printing layer 5 Surface protective layer 6 Embossed Pattern

Claims

1. A paper substrate; a foamed resin layer formed of a resin composition containing an aqueous emulsion resin, a foaming agent, and an inorganic filler; A surface protection layer mainly composed of acrylic resin is laminated in this order. The paper substrate has a basis weight of 50 g / m ２ More than 100g / m ２ The thickness is within the range of 80 μm or more and 150 μm or less, The resin composition contains, in a dry state, the inorganic filler in a range of 50 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the aqueous emulsion resin, and the foaming agent in a range of 1 part by mass or more and 20 parts by mass or less relative to 100 parts by mass of the aqueous emulsion resin, and the foamed resin layer has a basis weight after drying of 120 g / m ２ More than 170g / m ２ The expansion ratio is within the following range, and the expansion ratio is 5 times or more, and the aqueous emulsion resin is an ethylene-vinyl acetate copolymer or a mixture of an ethylene-vinyl acetate copolymer and an acrylic resin, The surface protective layer has a dry basis weight of 1 g / m ２ 40g / m or more ２ Foam wallpaper characterized by the following:

2. 2. The foamed wallpaper according to claim 1, further comprising a pattern printed layer having a printed pattern between the foamed resin layer and the surface protective layer.

3. 3. The foam wallpaper according to claim 1, wherein the surface protective layer is embossed.

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