JP6657763B2 - How to make wallpaper - Google Patents

Description

  The present invention relates to the manufacture of wallpaper.

In order to improve the concealing property of concealing dents, gaps, steps, and the like existing on the wall surface of the base, the wallpaper may require a sense of volume.
Here, in the wall covering composed of the backing paper for wallpaper and the resin layer, the volume feeling is increased by thickening the resin layer or foaming the resin and increasing the expansion ratio as in the wallpaper of Patent Document 1. Can be raised.
However, when the resin layer is simply thickened, the pressure resistance and the surface strength cannot be maintained, and the pressure resistance and the surface strength are reduced.
Here, as a method of achieving both the expansion ratio and the strength of the resin layer, it is conceivable to form a multilayer by extrusion molding or a coating method, but all require specialized processing machines, and productivity is difficult due to difficulty in processing. descend.

JP 2008-38265 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a wallpaper comprising a backing paper and a foamed resin layer, which can improve pressure resistance and surface strength by simple means.

  In order to solve the problem, a method for manufacturing a wallpaper, which is one embodiment of the present invention, is a method for manufacturing a wallpaper having a backing paper and a foamed resin layer formed on the backing paper. At least a first foaming agent and a second foaming agent having a foaming start temperature higher than the first foaming agent are added to the resin constituting the above, and the foaming start temperature of the first foaming agent or more is added. A first foaming step of heating at a first heating temperature, which is a temperature lower than the foaming start temperature of the second foaming agent, for a preset time, and a foaming of the second foaming agent after the first foaming step. A second foaming treatment step of heating at a second heating temperature that is equal to or higher than the starting temperature.

  ADVANTAGE OF THE INVENTION According to the wallpaper which is the aspect of this invention, even if it foams until the volume feeling sufficient to obtain non-landing concealment property is obtained, it is possible to provide wallpaper with improved pressure resistance and surface strength by simple means.

It is a typical sectional view for explaining wallpaper concerning an embodiment based on the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the wallpaper base paper of the present embodiment has a foamed resin layer 2 formed on one surface of a backing paper 1, and a printing layer 3 and a coat layer 4 are formed on the foamed resin layer 2. Is formed. The surface of the wallpaper is provided with an uneven pattern 5 by processing such as embossing. Here, as the wallpaper of the present embodiment, the print layer 3, the coat layer 4, and the uneven pattern 5 may be omitted.

<Backing paper 1>
The backing paper 1 is not particularly limited as long as it has mechanical strength, heat resistance, and the like suitable as a base material of the foamed wallpaper. The backing paper 1 is made of, for example, a resin sheet, a fibrous sheet (such as paper), or the like.
As the backing paper 1, a fibrous sheet such as paper is particularly preferable. Examples of the fibrous sheet include plain paper, flame-retardant paper (a pulp-based sheet treated with a flame retardant such as guanidine sulfamate and guanidine phosphate), and inorganic additives such as aluminum hydroxide and magnesium hydroxide. Inorganic paper, high-quality paper, thin paper, and the like. In the present embodiment, paper containing little or no inorganic additive, for example, plain paper is used.
As the backing paper 1, for example, a paper having a basis weight of 50 to 100 g / m ² and a thickness of 80 to 150 μm is employed. This makes it possible to secure the rigidity required for the wall covering material.

<Foam resin layer 2>
The foamed resin layer 2 is a foamed resin layer containing a resin such as a vinyl chloride resin or an olefin resin as a main component and containing a foaming agent.
The degree of polymerization of the resin constituting the foamed resin layer 2 is preferably 1000 or more. By setting the degree of polymerization to 1,000 or more, the surface strength of the wallpaper can be increased.
A foaming agent is mixed in the foamed resin layer 2 and foamed by a heat treatment. The expansion ratio is 3 times or more and 6 times or less.
As the foaming agent, known or commercially available foaming agents can be used. For example, azo compounds such as azodicarbonamide and azobisisobutyronitrile; sulfonyl hydrazide compounds such as paratoluenesulfonyl hydrazide and oxybisbenzenesulfonyl hydrazide; nitroso compounds such as N, N'-dinitrosopentamethylenetetramine; A pyrolytic blowing agent such as ammonium, sodium boron hydride, potassium hydrogen carbonate, sodium hydrogen carbonate, or the like can be used. Of these, two or more foaming agents having different foaming start temperatures are added.

For example, ADCA (azodicarbonamide foaming agent) and OBSH (oxybissulfonylhydrazide foaming agent) are used as foaming agents to be added. For example, the two foaming agents ADCA and OBSH are mixed at a ratio of 3: 1 to 1: 1 in order to secure the foaming ratio and prevent the foaming surface from being roughened. Mix to make 4 parts.
As the foam stabilizer, two kinds of stabilizers (barium salt-based and zinc salt-based) are added at a ratio of 1: 4 to 4: 1 in order to impart thermal stability and increase the foam thickness. It can be mixed so as to become 1 to 4 parts with respect to 100 parts of the resin.

The foamed resin layer 2 has a basis weight of 50 to 280 g / m ² and a foaming ratio of 3 times or more, so that the foamed resin layer 2 has a sufficient volume feeling to obtain non-landing concealability and has excellent surface strength. The embossed surface uneven pattern 5 can also be reproduced sharply.
In the foamed resin layer 2, a plasticizer, a viscosity reducing agent and other organic additives and an inorganic powder may be appropriately mixed according to the intended use.
The inorganic powder includes calcium carbonate, aluminum hydroxide, magnesium hydroxide, silica sand, talc, silicas, magnesium silicate, zinc borate, titanium dioxide and the like. It is preferable to add 40 to 150 parts of the inorganic powder to 100 parts of the vinyl chloride resin constituting the foamed resin layer 2. Here, when the amount of the inorganic powder exceeds 150 parts, the non-combustibility is increased, but the volume feeling may be reduced.

<Printing layer 3>
The printing layer 3 is provided on the foamed resin layer 2 in a sheet shape or a pattern shape by a calender molding method, a coating method, a screen printing method, or the like.
The printing layer 3 is formed using a printing ink (non-foamable ink) and / or a foamable ink mainly containing an aqueous emulsion resin, a foamable ink mainly containing a vinyl chloride paste resin, or the like.
<Coat layer 4>
The coat layer 4 is a layer that protects the surface of the wallpaper.
<Uneven pattern 5>
The concavo-convex pattern 5 may be partially foamed with a foam-suppressing ink or chemically embossed by partially heating and foaming with hot air or infrared rays. On the other hand, it is preferable because sharp unevenness can be obtained.

<Foaming treatment>
Here, the foaming start temperatures T1 and T2 of the two types of foaming agents added to the foamed resin layer 2, where T1 <T2. Here, another foaming agent may be contained.
As a first foaming treatment step, the above-mentioned wallpaper base paper is first heated at a first heating temperature which is a heating temperature higher than T1, preferably higher than T1 and lower than T2 for a predetermined time (for example, 5 seconds or more), The foaming agent having the lower foaming start temperature is foamed first. At this time, the predetermined heating time is not necessarily required to be a heating time for 100% foaming of the foaming agent having a low foaming start temperature. % Or more heating time until foaming.

Next, as a second foaming treatment step, the non-foamed foaming agent is foamed by heating at a heating temperature of T2 or more, preferably higher than T2 for a predetermined time (for example, 10 seconds or more).
The foaming start temperature T1 is, for example, in the range of 140 ° C. to 180 ° C., and the foaming time is 20 seconds to 40 seconds. The foaming start temperature T2 is, for example, in the range of 190 ° C. to 230 ° C., and the foaming time is 5 seconds to 60 seconds.
Here, it is preferable that the foaming start temperatures T1 and T have a temperature difference of 10 ° C. or more.

In this way, by performing foaming in two stages, the foamed cells in the foamed resin layer 2 become denser than when foaming is performed in two stages. As a result, even if the foaming ratio is set to 3 times or more and a sufficient volume feeling is imparted to the foamed resin layer 2 to obtain the non-landing concealing property, the wallpaper has excellent pressure resistance and surface strength.
This means that even if the uneven pattern 5 is provided by embossing or the like, the uneven shape can be sharply reproduced.
Here, by adding 40 parts or more of the inorganic powder to the foamed resin layer 2, the foaming gas can be appropriately released, and the shape of the void (cell) formed by foaming can be made appropriate.
However, if the amount of the inorganic powder exceeds 150 parts, the volume is reduced, so the upper limit is 150 parts.

Next, examples of the present invention will be described.
<Example 1>
Plain paper having a basis weight of 65 g / m ^{2 and a} thickness of 110 μm (Nippon Paper Industries Co., Ltd .: “NI65AT”) was used as the backing paper 1 for wallpaper.
On the backing paper 1 for the wallpaper, 100 parts of an inorganic powder in a vinyl chloride resin (manufactured by Tosoh Corporation: "SP-039", degree of polymerization 1050), 2 parts of ADCA as a foaming agent, and 1 part of OBSH The paste to which 0.5 part was added was applied by a coating method so as to have a basis weight of 300 g / m ² to form a foamed resin layer 2, which was heated and foamed (foaming ratio 3 times), and further pressurized and cooled with an embossing roll. Then, it was dried to obtain the wallpaper of Example 1.
The above-mentioned thermal foaming was performed by heating at a paper surface temperature of 145 ° C. for 10 seconds as a first foaming process, and then performing foaming by heating at a paper surface temperature of 210 ° C. for 20 seconds as a second foaming process.

<Example 2>
Plain paper having a basis weight of 65 g / m ^{2 and a} thickness of 110 μm (Nippon Paper Industries Co., Ltd .: “NI65AT”) was used as the backing paper 1 for wallpaper.
On the backing paper 1 for the wallpaper, 100 parts of an inorganic powder in a vinyl chloride resin (manufactured by Tosoh Corporation: "SP-039", degree of polymerization 1050), 2 parts of ADCA as a foaming agent, and 1 part of OBSH The paste to which 0.5 part was added was applied by a coating method so as to have a basis weight of 300 g / m ² to form a foamed resin layer 2, and a pattern was printed thereon by gravure printing using an aqueous ink, Heat foaming (expansion ratio 3 times) was performed, embossing was further performed by pressing with an embossing roll, and then cooled and dried to obtain the wallpaper of Example 2.
The above-mentioned thermal foaming was performed by heating at a paper surface temperature of 145 ° C. for 10 seconds as a first foaming process, and then performing foaming by heating at a paper surface temperature of 210 ° C. for 20 seconds as a second foaming process.

<Comparative Example 1>
The wallpaper of Comparative Example 1 was obtained in the same manner as in Example 2, except that the first foaming step was omitted and only the second foaming step was performed as the heat foaming.
<Comparative Example 2>
A wallpaper of Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that the blowing agent was changed to only 2.5 parts of ADCA.

<Evaluation method>
The feeling of volume was measured by measuring the thickness using a dial thickness gauge and evaluating whether the thickness exceeded 0.5 mm.
The non-landing concealment property is to determine whether or not the location can be visually identified by illuminating one side with a circular seal with a thickness of 110 µm and a diameter of 20 mm on a gypsum board (thickness of 9.5 mm) of quasi-nonflammable standard. evaluated.
The pressure resistance was measured by applying a load of 1 kg / m ² using a blocking tester, storing the product at a temperature of 25 ° C. and a humidity of 60% for 24 hours, decompressing it for 24 hours, and setting the pressure to 100%. The evaluation was made based on whether or not the ratio of the thickness after elapse of 24 hours after decompression exceeded 90%.
The surface strength was determined by visually inspecting the state of surface damage at the time of scratching, and evaluating whether or not the base paper layer was exposed, by a test in accordance with the standard “Surface Reinforced Wallpaper Performance Rules” established by the Wallpaper Industry Association.
<Evaluation results>
Table 1 shows the evaluation results.

As can be seen from Table 1, it was confirmed that the wallpapers of Examples 1 and 2 based on the present invention had good volume feeling, non-landing concealability, pressure resistance, and surface strength.
On the other hand, in the wallpaper of Comparative Example 1, even when the same foaming agent as in Example 2 is applied, the pressure resistance and the surface strength are lower than those of Examples 1 and 2.

1 backing paper 2 foam resin layer 3 print layer 4 coat layer 5 uneven pattern

Claims (8)

A method for producing wallpaper having a backing paper and a foamed resin layer formed on the backing paper,
To the resin constituting the foamed resin layer, at least a first foaming agent and a second foaming agent having a foaming start temperature higher than the first foaming agent are added as foaming agents,
A first foaming treatment step of heating at a first heating temperature that is equal to or higher than the foaming start temperature of the first foaming agent and lower than the foaming start temperature of the second foaming agent for a preset time;
After the first foaming step, a second foaming step of heating at a second heating temperature that is equal to or higher than the foaming start temperature of the second foaming agent;
Equipped with a,
The total amount of the content of the first foaming agent and the content of the second foaming agent is within a range of 1 part by mass or more and 4 parts by mass or less based on 100 parts by mass of the resin constituting the foamed resin layer. Wallpaper method of manufacture, wherein the Rukoto Oh.   The method according to claim 1, wherein the foaming ratio of the foamed resin layer is 3 times or more. The foamed resin layer further contains a foaming stabilizer,
The foam stabilizer includes two types of a barium salt-based stabilizer and a zinc salt-based stabilizer,
The mass ratio between the content of the barium salt-based stabilizer and the content of the zinc salt-based stabilizer is in the range of 1: 4 to 4: 1. Item 3. A method for producing a wallpaper according to Item 2. The foamed resin layer further contains a foaming stabilizer,
The foam stabilizer includes two types of a barium salt-based stabilizer and a zinc salt-based stabilizer,
The total amount of the content of the barium salt-based stabilizer and the content of the zinc salt-based stabilizer is 1 part by mass or more and 4 parts by mass or less based on 100 parts by mass of the resin constituting the foamed resin layer. The method for producing wallpaper according to any one of claims 1 to 3, wherein the thickness is within the range of: The wallpaper according to any one of claims 1 to 4, wherein in the first foaming step, the first foaming agent is heated so as to leave a part of the first foaming agent in an unfoamed state. Production method. The said 2nd foaming process WHEREIN: The said 1st foaming agent and the said 2nd foaming agent which were not foamed in the said 1st foaming process are foamed, respectively, The foaming characterized by the above-mentioned. Wallpaper manufacturing method. The wallpaper manufacturing method according to any one of claims 1 to 6, wherein a heating time in the first foaming process is shorter than a heating time in the second foaming process. The wallpaper further has a printing layer formed on the foamed resin layer,
The method according to any one of claims 1 to 7, wherein the printing layer is formed using a foaming ink containing a vinyl chloride paste resin as a main component.

Images