JP2005248400A - Paper wallpaper and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide paper wallpaper having recyclability and excellent designability such as embossing suitability and printing suitability and further excellent removability. <P>SOLUTION: The paper wallpaper is obtained from ≥3 plies of multiply combination paper composed of the top paper ply having ≥10 to ≤30 g/m<SP>2</SP>Cobb water absorption degree, at least one middle paper ply consisting essentially of heat fusible synthetic fibers and natural pulp and at least one backing paper ply consisting essentially of natural pulp. The top paper ply has preferably ≥10 to ≤50 g/m<SP>2</SP>basis weight and ≥70% brightness degree. The middle paper ply has preferably ≥50 to ≤200 g/m<SP>2</SP>basis weight in (95:5) to (5:95) compounding ratio of the heat fusible synthetic fibers to the natural pulp expressed in terms of weight ratio. The backing paper ply has preferably ≥50 to ≤200 g/m<SP>2</SP>basis weight, ≥40% brightness degree and ≥10 to ≤30 g/m<SP>2</SP>Cobb water absorption degree. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The product of the present invention relates to a paper wallpaper having reproducibility, and relates to a paper wallpaper made of multilayered laminated paper that can be produced in a batch in a papermaking process, which has excellent design properties such as embossability and printability, and excellent removability.

  Conventionally, vinyl chloride wallpaper has been widely used as most wallpaper. Vinyl chloride wallpaper is superior to other materials in terms of cost, design, workability, etc., but dioxins may be generated when it is incinerated as waste. The demand for “vinyl chloride wallpaper” is increasing in the market. Under these circumstances, in recent years, wallpaper or paper wallpaper in which a synthetic resin such as an olefin type resin is coated or bonded instead of vinyl chloride wallpaper is increasing.

   In general, the paper wallpaper is composed of two layers of upper layer paper and backing paper. In addition, an adhesive or a heat-fusible film is used for bonding between the upper layer paper and the backing paper, and after the upper layer paper and the backing paper are bonded, printing or embossing is performed on the paper itself, It is constructed as a paper wallpaper.

  However, the paper wallpaper obtained by these methods is individually produced with an upper layer paper and a backing paper, and the upper layer paper contains synthetic fibers. The inferiority and the pasting processing of the upper layer paper and the backing paper are indispensable. Therefore, the cost is higher than that of the vinyl chloride wallpaper, and there is a problem of removability like the vinyl chloride wallpaper. JP-A-2003-13397 (Patent Document 1), JP-A-2003-25503 (Patent Document 2), and JP-A-2003-286699 (Patent Document 3) disclose wallpaper for multilayer paper. Thus, providing a layer containing synthetic fibers is effective in improving embossability.

JP 2003-13397 A Japanese Patent Laid-Open No. 2003-25503 JP 2003-286699 A

  However, the above-described multilayer paper wallpaper has problems in printability and surface strength. Accordingly, an object of the present invention is to provide a multilayer paper that can be manufactured at low cost by batch production in the paper making process and is excellent in embossability, printability, and removability.

Therefore, as a result of intensive studies to solve the above-mentioned drawbacks, the inventors have made an upper layer paper layer that has natural pulp as a main component and imparts printability, a heat-fusible synthetic fiber and natural pulp as main components to have embossability. At least one layer of intermediate paper layer to be applied, and three or more layers of laminated paper composed of at least one backing paper layer mainly composed of natural pulp. Further, printability, surface strength, dirt, water repellency, and dimensional stability The above problems have been solved by using a paper wallpaper having a bump water absorption of 10 g / m ² or more and 30 g / m ² or less for the upper layer paper layer due to its properties.

In the present invention, the upper paper layer that imparts printability has a blending ratio of natural pulp of 80% by weight or more with respect to the total fiber content, and the basis weight is in the range of 10 g / m ^{2 to} 50 g / m ² , The whiteness is preferably 70% or more so that the printed pattern will flourish.

In the intermediate paper layer imparting embossability, the blending ratio of the heat-fusable synthetic fiber and the natural pulp is preferably 5:95 to 95: 5 by weight. The basis weight of the intermediate paper layer is preferably 50 g / m ² or more and 200 g / m ² or less.

The backing paper layer has a natural pulp content of 80% by weight or more based on the total fiber content, and a basis weight of 50 g / m ² or more and 200 g / m ² or less, and whiteness is 40% to prevent show-through. In order to prevent penetration of the pressure-sensitive adhesive and to stabilize the size of the cover, it is preferable that the water absorption of the bumps is 10 g / m ² or more and 30 g / m ² or less.

  The paper wallpaper of the present invention is excellent in embossability, printability, and removability, and can be manufactured at low cost because it does not require a bonding process by manufacturing by multi-layer bonding in the papermaking process.

  Hereinafter, the present invention will be described in detail.

  The paper wallpaper of the present invention comprises an upper paper layer composed mainly of natural pulp, an intermediate paper layer composed mainly of heat-fusable synthetic fibers and natural pulp, and at least one layer, and natural pulp composed of at least one layer. The synthetic paper and the natural pulp are not particularly limited.

The upper paper layer imparting printability preferably has a natural pulp content of 80% by weight or more based on the total fiber content. When the blending ratio of natural pulp is less than 80% by weight, smoothness and printability are poor. The basis weight of the upper paper layer is preferably in the range of 10 g / m ^{2 to} 50 g / m ² . When the basis weight is less than 10 g / m ² , smoothness and printability are inferior, and when it exceeds 50 g / m ² , embossability is inferior. The whiteness is preferably 70% or more, and if it is less than 70%, the printed pattern does not grow.

It is essential that the water absorption of the upper paper layer is 10 g / m ² or more and 30 g / m ² or less. If the Cobb water absorption is less than 10 g / m ² , the water-based ink is repelled, so the printability is inferior, and if it exceeds 30 g / m ² , the water repellency is inferior and stains easily occur.

  In the intermediate paper layer, the blending ratio of the heat-fusable synthetic fiber and the natural pulp is preferably 5:95 to 95: 5, and particularly preferably 20:80 to 80:20. When the blending ratio of the heat-fusible synthetic fiber is less than 5% by weight, the embossability of the multilayer paper is inferior, and even if the blending ratio is increased beyond 95% by weight, the embossing suitability is not expected and the interlaminar strength decreases. , So-called peeling occurs.

  Examples of heat-fusible synthetic fibers used in the intermediate paper layer include polyolefin fibers such as polyethylene and polypropylene, polyester fibers, acrylonitrile fibers, vinylon fibers, polyamide fibers, and rayon fibers regenerated from cellulose. It is done. Further, examples include pulp-like multi-branched fibers obtained by processing polyolefin-based resins such as polyethylene and polypropylene into multi-branched fibers, and polyolefin-based composite fibers represented by a core-sheath type composed of a combination of two components having different melting points. As such a pulp-like multi-branched fiber, as described in Japanese Patent No. 2734832, it is a form composed of a trunk fiber and a branched fiber branched from the trunk fiber, and the average fiber diameter of the trunk fiber Is in the range of 0.5 to 5 μm, the average fiber diameter of the branched fibers is less than 0.5 μm, and the average fiber length from the tip of the branched fiber to the tip of the other branched fiber is 0.01 mm to 10 mm. Synthetic pulp is preferred. A preferred example of such a pulp-like multi-branched fiber is a polyolefin-based synthetic pulp marketed by Mitsui Chemicals, Inc. under the trade name SWP.

  The melting point of the heat-fusible synthetic fiber is preferably 100 to 180 ° C. This is because the embossing is usually performed in this temperature range, so that the heat-fusible synthetic fiber melts in the embossing process and the embossing process is improved.

  Natural pulps used in the upper paper layer, intermediate paper layer, and backing paper layer include chemical pulp (conifer bleached kraft pulp (NBKP) or unbleached kraft pulp (NUKP), hardwood bleached kraft pulp (LBKP) or not Bleached kraft pulp (LUKP), softwood bleached sulfite pulp (NBSP) or unbleached sulfite pulp (NUSP), hardwood bleached sulfite pulp (LBSP) or unbleached sulfite pulp (LUSP), etc., mechanical pulp ( Non-wood fiber pulp such as ground pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), deinked pulp (DIP), cotton, kenaf, etc. It is done. These natural pulps are used alone or mixed at an arbitrary ratio.

The basis weight of the intermediate paper layer is preferably 50 g / m ² or more and 200 g / m ² or less. If the basis weight is less than 50 g / m ² , the embossability is inferior, and if it exceeds 200 g / m ² , further improvement in embossability cannot be expected, and the cost increases.

  In the present invention, the backing paper layer containing natural pulp as a main component preferably has a natural pulp content of 80% by weight or more based on the total fiber content. If the blending ratio of natural pulp is less than 80% by weight, machine dirt or paper breakage, so-called paper breakage, is likely to occur in operability.

The basis weight of the backing paper layer mainly composed of natural pulp is preferably 50 g / m ² or more and 200 g / m ² or less. If the basis weight is less than 50 g / m ² , sufficient strength cannot be obtained, and if it exceeds 200 g / m ² , there is a drawback that it becomes too hard as a wallpaper product and construction becomes difficult. The whiteness of the backing paper layer is preferably 40% or more, and when it is less than 40%, the color of the surface layer portion changes and the printed pattern does not prosper. Moreover, it is preferable that a Cobb water absorption is 10 g / m ² or more and 30 g / m ² or less. If the water absorption of the bumps is less than 10 g / m ² , the adhesion of the water-based paste becomes worse, and it becomes easy to peel off after construction. On the other hand, when the water absorption of the bumps exceeds 30 g / m ² , the water-based paste is easily soaked, and the dimensional stability of the weathering after construction is deteriorated.

  In order to make the multilayer paper of the present invention, the paper can be made with a paper machine having a structure capable of three or more layers of paper, for example, a long mesh paper machine, a long mesh paper mesh Conventional papermaking techniques such as papermaking machines, short netting papermaking machines, circular netting papermaking machines, etc. can be applied as appropriate, or papermaking can be performed with a papermaking machine with a headbox for multilayer papermaking. Also good.

  The sheet structure of the paper wallpaper comprising the multilayer paper of the present invention is basically an upper layer / intermediate layer / backing layer, but the intermediate layer or the backing layer may be two or more layers, It can be appropriately selected according to the purpose.

  In addition, as long as the effects of the present invention are not impaired, fillers and auxiliary agents such as sizing agents, yield improvers, paper strength agents, and the like can be used as needed in the paper, and the pH during papermaking is acidic papermaking. There is no problem even if it is in the range from about 4.5 to about 6-8 of neutral papermaking. In addition, starch, polyvinyl alcohol, polyacrylamide, styrene-acrylic co-polymerized paper on the surface of the obtained multilayer paper by a size press device such as a 2-roll coater or a gate roll coater, a blade coater, a rod coater, a spray device, etc. Various surface sizing agents such as coalescence, styrene / butadiene-based; acrylic acid ester-based; ethylene vinyl acetate-based; vinyl acetate-based; urethane-based latex, surface strength agents, pigments, dyes, and the like can be applied.

  The layer configuration of the multilayer paper of the present invention, the basis weight of each layer, the compounding chemicals, and the like are appropriately determined according to the purpose and application. The multilayer paper of the present invention thus obtained has high bulkiness, has good operability during papermaking, and is extremely useful in practice.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. “%” Represents “% by weight” unless otherwise specified.

<Heat-synthetic synthetic fiber (raw material A)>
Polyolefin-based synthetic pulp (trade name: SWP E790, average fiber length of 1.6 mm, density of 0.96 g / cm ³ , pulp-like multibranched fiber having a melting point of 135 ° C., manufactured by Mitsui Chemicals, Inc.) was disaggregated to obtain raw material A.

<Beat hardwood bleached kraft pulp (raw material B)>
Hardwood bleached kraft pulp (LBKP, Nippon Paper Industries Co., Ltd.) was beaten using a double disc refiner to obtain a raw material B having a Canadian Standard Freeness (hereinafter, CSF) of 440 ml.

<Cotton linter pulp (raw material C)>
After understanding a commercially available cotton linter pulp for papermaking (manufactured by Bukeye), it was beaten using a double disc refiner to obtain 650 ml of raw material C.
<Beat-conifer bleached kraft pulp (raw material D)>
Softwood bleached kraft pulp (NBKP, Nippon Paper Industries Co., Ltd.) was beaten using a double disc refiner to obtain DF 550 ml of raw material D.

<Beat thermomechanical pulp (raw material E)>
Thermomechanical pulp (TMP, manufactured by Nippon Paper Industries Co., Ltd.) was beaten using a double disc refiner to obtain 220 ml of CSF raw material E.

[Example 1]
<Upper paper layer>
The raw material (B) has a sulfuric acid band of 1.0% by weight per pulp dry weight, a rosin sizing agent of 0.5% by weight of pulp dry weight, and a paper strength agent (polyacrylamide) by 0.5% by weight of pulp dry weight. It added so that it might become paper stock.
<Intermediate paper layer>
The mixing ratio of raw material (A) and raw material (C) is adjusted to A / C = 50/50, the sulfuric acid band is 1.0% by weight per pulp dry weight, and the rosin size is per dry pulp weight 0.5% by weight and a paper strength agent (polyacrylamide) was added to a weight of 0.5% by weight based on the absolute dry weight of the pulp to obtain a paper stock.
<Backing paper layer>
The raw material (B), the raw material (D), and the raw material (E) were adjusted so that the blending ratio was B / D / E = 50/30/20, and the sulfuric acid band was 1.0% by weight with respect to the absolute dry weight of the pulp, rosin A sizing agent was added at 0.5% by weight per pulp dry weight, and a paper strength agent (polyacrylamide) was added at 0.5% by weight per pulp dry weight to obtain a paper stock.
<Making of multi-layer paper>
The above-prepared paper is made with a multi-layer paper machine, the upper paper layer is made with a long mesh, the intermediate paper layer is made with an inclined wire, and the backing paper layer is made with a multi-layer multi-layer paper machine. Three-layer papermaking was performed so that the basis weight of the paper layer was 70 g / m ² , the intermediate paper layer had a basis weight of 100 g / m ² , and the upper layer paper layer had a basis weight of 40 g / m ^2, and the total basis weight was 210 g / m ^2. A multilayer paper of m ² was obtained.

[Example 2]
Using the paper stock prepared in Example 1, the basis weight of the upper layer paper layer is 20 g / m ² , the basis weight of the intermediate paper layer is 100 g / m ² , and the basis weight of the backing paper layer is 90 g / m on a multilayer paper machine. ^A three-layer paper was made so as to obtain a multilayer paper having a total basis weight of 210 g / m ² .

[Example 3]
Using the paper stock prepared in Example 1, the basis weight of the upper layer paper layer is 40 g / m ² , the basis weight of the intermediate paper layer is 80 g / m ² , and the basis weight of the backing paper layer is 90 g / m on a multilayer paper machine. ^A three-layer paper was made so as to obtain a multilayer paper having a total basis weight of 210 g / m ² .

[Comparative Example 1]
Without providing an upper paper layer in a multilayer paper machine, the paper weight used for the intermediate paper layer of Example 1 was used, the basis weight was 100 g / m ² , and the paper material used for the backing paper layer of Example 1 was used. Two-layer paper was made so that the basis weight of the backing paper layer was 100 g / m ^2, and a two-layer paper having a total basis weight of 200 g / m ² was obtained.

[Comparative Example 2]
The paper stock prepared in Example 1 was used, the paper stock used for the intermediate paper layer was used for the upper paper layer in the multilayer paper machine, and the paper stock used for the upper paper layer was used for the intermediate paper layer. Three-layer papermaking was performed so that the basis weight of the layer was 40 g / m ² , the basis weight of the intermediate paper layer was 100 g / m ² , and the basis weight of the backing paper layer was 70 g / m ^2, and the total basis weight was 210 g / m ² . A multilayer paper was obtained.

[Comparative Example 3]
Using the paper stock prepared in Example 1, without providing an intermediate paper layer with a multilayer paper machine, the basis weight of the upper paper layer is 100 g / m ² and the basis weight of the backing paper layer is 100 g / m ^2. A two-layer paper was obtained, and a two-layer paper having a total basis weight of 200 g / m ² was obtained.

[Comparative Example 4]
A multilayer paper was obtained in the same manner as in Example 1 except that, in the upper paper layer, a raw material (C) to which no sizing agent was added was used as a paper stock.

The paper wallpaper obtained in Examples and Comparative Examples was evaluated for the following items, and the results are shown in Table 1.
<Evaluation method and judgment>
(1) Evaluation of embossing suitability: The surface temperature of the embossing roll was set to 210 ° C. between the metal embossing roll and the back rubber roll having a flat surface, and embossing was performed on the sheet surface side. If the resulting embossed irregularities were clear, it was marked as ◯, if it was unclear, it was marked as x, and if it was between, it was marked as Δ.
(2) Evaluation of printability: Using a water-based medium ink, printing was performed with a gravure printability tester under a printing pressure of 10 kg / m ² and a speed of 20 m / min. The obtained printed surface was observed, and the one with a clean printed surface was marked with ◯, the one with much whitening was marked with ×, and the middle was marked with Δ.
(3) Cobb water absorption: Measured according to JIS P8140 or ISO 535.
(4) Whiteness: Measured according to JIS P8148 or ISO 2470.

As is clear from the results in Table 1, the paper wallpaper made of the multilayer paper of the present invention of Examples 1 to 3 is capable of batch production of paper wallpaper and has excellent practicality such as embossability and printability. there were. On the other hand, the paper wallpaper of the comparative example 1 which does not provide the upper paper layer which has a natural pulp as a main component was inferior in printability. Further, the paper wallpaper of Comparative Example 2 in which a layer mainly composed of heat-fusable synthetic fibers and natural pulp is provided as an upper layer paper layer and a layer mainly composed of natural pulp as an intermediate paper layer is inferior in printability. The embossability was also insufficient. The paper wallpaper of Comparative Example 3 in which no intermediate paper layer mainly composed of heat-fusible synthetic fibers and natural pulp was provided was inferior in embossability. The paper wallpaper of Comparative Example 3 in which the water absorption of the upper layer paper layer exceeds 30 g / m ² was inferior in printability.

Claims (5)

An upper paper layer having a natural pulp as a main component and having a water absorption of 10 g / m ² or more and 30 g / m ² or less, a heat fusible synthetic fiber and a natural pulp as a main component, and at least one intermediate paper layer and a natural pulp. A paper wallpaper which is a multi-layered laminated paper composed of at least one backing paper layer as a main component. The intermediate paper layer is characterized in that the blending ratio of the heat-fusible synthetic fiber and the natural pulp is 5:95 to 95: 5 by weight, and the basis weight is 50 g / m ² or more and 200 g / m ² or less. The paper wallpaper according to claim 1. The paper wallpaper according to claim 1 or ² , wherein the upper paper layer has a basis weight of 10 g / m ² or more and 50 g / m ² or less and a whiteness of 70% or more. The backing paper layer has a basis weight of 50 g / m ² or more and 200 g / m ² or less, a whiteness of 40% or more, and a bump water absorption of 10 g / m ² or more and 30 g / m ² or less. Paper wallpaper written in the crab. Three or more layers consisting of an upper layer paper layer mainly composed of natural pulp, a heat-fusible synthetic fiber and at least one intermediate paper layer mainly composed of natural pulp, and at least one backing paper layer mainly composed of natural pulp. A method for producing paper wallpaper, characterized in that a multi-layered paper is made by a multi-layer paper machine.