JP2003003397A - Two-layered foamed paper and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamed paper useful as a base paper for a wall paper or the like, and having excellent dimensional stability, flexibility and curl resistance. SOLUTION: This method for producing a double layered foamed paper is characterized in that the first layer (2) comprising a pulp and a synthetic fiber as essential components, and the second layer (3) formed thereon, and comprising the pulp, the synthetic fiber and a heat-foamable agent as essential components are made into two layers by papermaking, and the obtained paper is heated to foam the heat-foamable agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a foamed paper having excellent dimensional stability, flexibility and curl resistance, which is useful as a base paper for wallpaper, fusuma paper, exhibition paper, booth paper and the like.

[0002]

2. Description of the Related Art As a conventional wallpaper, a so-called vinyl chloride wallpaper in which a vinyl chloride resin layer is provided on a sheet base material has been widely used. Vinyl chloride wallpaper is easy to emboss and has excellent design, but in the manufacturing process,
When adhering the vinyl chloride resin layer to the sheet base material, an adhesive containing an organic solvent must be applied, and the organic solvent volatilizes in the work environment and deteriorates the work environment. Also,
When such a vinyl chloride wallpaper is used as a home interior material, it is feared that the organic solvent will gradually evaporate from the adhesive layer, deteriorating the indoor environment and contributing to chemical sensitivity. ing.

Therefore, a wallpaper made of a paper material coated with a non-organic solvent type adhesive has come to be used. But,
Since it is difficult to emboss the wallpaper of paper materials, usually a heating foaming agent is blended with the raw material pulp, and it is applied on heat-foamed paper or paper material after papermaking and heat foamed as the base material. Often.

[0004]

However, the conventional wallpaper made of foamed paper has insufficient dimensional stability and is slightly poor in flexibility. In particular, if a water-soluble adhesive is applied to a wallpaper made of conventional foamed paper, and the glue surface is applied with water when attempting to stick it on a wall, the wallpaper will curl and the construction efficiency will drop significantly. There is a problem.

The problem to be solved by the present invention is to provide a foamed paper which is useful as a base paper for wallpaper or the like and which is excellent in dimensional stability, flexibility and curl resistance.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies and have found that the above problems can be solved by blending synthetic fibers and further making a two-layer papermaking, and completed the present invention.

That is, according to the present invention, a first layer containing pulp and synthetic fibers as essential components and a second layer containing pulp, synthetic fibers and a heat-foaming agent as essential components on top of them are made into two layers and heated. The present invention relates to a method for producing a two-layer foam paper, which comprises foaming a heating foaming agent.

The present invention also relates to 2
The present invention relates to a wallpaper comprising an aqueous resin adhesive layer provided on the surface of the first layer surface or the second layer surface of the multi-layer foam paper.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

The present invention is characterized in that two layers of a first layer and a second layer containing a heat-foaming agent shown below are produced, and the heat-foaming agent is foamed by heating.

First, the first layer is a paper made from a slurry containing pulp and synthetic fibers as essential components.

The pulp as the first raw material for the first layer is not particularly limited, but is preferably a mixed pulp of waste paper pulp and virgin pulp. With virgin pulp alone,
It has large expansion and contraction, and when printed with water-soluble ink on the surface of the paper, it will curl and distort, and when it is installed as wallpaper or fusuma paper, it will curl on the front side because it is different on the front side and back side, and after drying, As a result, the entire fusuma is warped and the joints of the wallpaper are opened, which is not preferable. By using waste paper pulp in combination, it is possible to obtain the effects of suppressing stretchability and increasing dimensional stability and flexibility. The mixing ratio of the waste paper pulp and the virgin pulp may be appropriately selected within a range of 74 to 52 parts by weight of waste paper pulp and 18 to 10 parts by weight of virgin pulp. Waste paper pulp is below the above range,
When the virgin pulp exceeds the above range, the dimensional stability and the flexibility of the obtained two-layer foam paper are deteriorated, which is not preferable.

Examples of the virgin pulp include wood pulp such as chemical and mechanical pulp of softwood and hardwood, and non-wood pulp.

The blending amount of pulp per first layer is 60-
It may be appropriately selected within the range of 92% by weight. If the amount of pulp is within the above range, dimensional stability, water-based printability,
Workability is good, but if it is out of the above range, dimensional stability, water-based printability, and workability are deteriorated, which is not preferable.

A heating foaming agent may be added for the purpose of making the first layer thick and bulky.

The synthetic fiber used as the second raw material for the first layer is at least one selected from rayon, acrylic, polyester and vinylon. By blending these synthetic fibers, flexibility, bulkiness, dimensional stability, and embossing (irregularities) easily occur, and workability is improved. For the purpose of improving dispersibility and making it bulky, these synthetic fibers are
You may mix and mix it in 1 or more types. As these synthetic fibers, those having a thickness of 0.5 to 6 denier and a fiber length of 2 to 5 mm can be used.

The blending amount of the synthetic fiber per the first layer is 5 to 5.
It may be appropriately selected within the range of 30% by weight. If the content of the synthetic fiber is less than 5% by weight, the dimensional stability is not obtained and the paper becomes hard, which is not preferable, and if it exceeds 30% by weight, the printability and the adhesiveness of the glue after construction are poor and the material is cut off. It is not preferable because it worsens.

By making the first layer from the slurry having the above composition, the surface of the first layer is excellent in smoothness, so that the printing in water-based or oil-based printing is good (clear). Suitable for water-based printing with less shrinkage. In addition, embossing is easy to occur and the embossed pattern is difficult to stretch.

As the pulp which is the first component of the second layer, it is preferable to use a mixed pulp of waste paper pulp and virgin pulp, as with the pulp of the first layer. The mixing ratio of the waste paper pulp and the virgin pulp may be appropriately selected within the range of 82 to 63 parts by weight of the waste paper pulp and 13 to 7 parts by weight of the virgin pulp.

The blending amount of pulp per second layer is 70-
It may be appropriately selected within the range of 95% by weight. If the amount of pulp is within the above range, dimensional stability, water-based printability,
Workability is good, but if it is out of the above range, dimensional stability, water-based printability, and workability are deteriorated, which is not preferable.

As the synthetic fiber as the second component of the second layer, at least one kind selected from rayon, acrylic, polyester and vinylon can be used as in the synthetic fiber of the first layer. The thickness and fiber length of the synthetic fiber are the same as those of the synthetic fiber.

The compounding amount of the synthetic fiber per second layer is 5 to
It may be appropriately selected within the range of 30% by weight. If the compounding amount of the synthetic fiber is less than 5% by weight, there is no dimensional stability.
If it is blended in excess of weight%, it is not preferable because it will be detached when dried after construction.

By blending synthetic fibers in the second layer,
Dimensional stability and flexibility can be improved.

The heating foaming agent which is the third component of the second layer is not particularly limited as long as it foams in the dryer step after the paper making step, and examples thereof include thermally expandable microcapsules containing various core substances. be able to. Examples of the core substance include low boiling point hydrocarbons such as isobutane. Examples of the shell material of the microcapsules include acrylonitrile / methyl methacrylate copolymer.

These heat-foaming agents preferably have a foaming temperature of about 85 to 120 ° C. so as to foam in the drying step after papermaking.

The compounding amount of the heating foaming agent per second layer is 3
It may be appropriately selected within the range of 5 wt%. If the content of the heat-foaming agent is less than 3% by weight, the effect of the foaming agent is not exerted, and if it exceeds 5% by weight, a crease remains after the construction or it is detached when dried, which is not preferable.

By blending the heat-foaming agent, the second layer becomes bulky and minute irregularities are formed on the back surface.

The second layer is bulky, is excellent in flexibility and dimensional stability, and has a rough back surface (unevenness) when applied, which easily sticks to glue and is detached even after drying after application. Absent.

Various types of conventionally used anionic, nonionic, cationic or amphoteric retention aids, paper strength enhancers, sizing agents, pigments, dyes, etc. are used in the pulp slurries for the first and second layers. May be added to the extent that the effects of the present invention are not impaired.

The two-layer foamed paper of the present invention is not particularly limited as long as it is a two-layer paper making method. For example, the first layer and the two layers, which are made of round steel or long steel, are made into a paper, Pressurized to produce a two-layer sheet, and then physically remove water to some extent with a press roll, and then 85 ° C with a dryer.
By foaming the foaming agent by heating to ~ 120 ° C,
It should be a product. Also, as a base paper for the product, the basis weight is 60 g /
It is preferably set to m ^{2 to} 150 g / m ² .

In order to use the two-layer foam paper of the present invention as a wallpaper, it is sufficient to apply an adhesive to the two-layer foam paper at the construction site and attach it to the wall. A wallpaper coated with a resin adhesive may be used.

The wallpaper of the present invention comprises the above-mentioned two-layer foamed paper as a base paper and a water-based resin adhesive applied thereto to form a water-based resin adhesive layer. The water-based resin adhesive in the present invention is not particularly limited as long as it is an adhesive containing no organic solvent, and examples thereof include water-based resin adhesives such as polyacryl, polyurethane, latex, polyvinyl acetate and polyvinyl alcohol. it can. The surface to which the adhesive is applied may be any surface of the two-layer foam paper. That is, it may be provided on the surface of the first layer side or the surface of the second layer side. When a water-based adhesive layer is provided on the foamed surface of the second layer, the water-based adhesive is applied to the surface of the second layer, which has fine irregularities on the surface due to the action of the foaming agent. Will increase. Further, when the water-based adhesive layer is provided on the surface of the first layer side, the foamed second layer becomes the surface of the wallpaper, and thus the surface having fine irregularities gives a visually graceful effect. Release paper is preferably attached to the surface of the water-based resin adhesive layer.

Further, the wallpaper of the present invention has a thickness.
, Lengthen the blocking time after applying glue, and
Efficiently delaminates from one side of the backing paper when replacing
The paper may be lined for the purpose. Backing paper is single-layer paper, double-layer paper
40 g / m² ~ 80g / m²Has a good basis weight and has a backing adhesive
The agent is an aqueous resin and is 10 g / m on a dry basis.² ~ 20 g / m
² Is good.

FIG. 1 is a sectional view of a two-layer foam paper 1 of the present invention. 2 is the first layer containing pulp and synthetic fibers. Reference numeral 3 is a second layer formed on the first layer. Second
The layer is a foamed paper layer in which a slurry containing pulp, synthetic fibers and a heating foaming agent is made into paper and heated to foam the foaming agent.

FIG. 2 is a sectional view of the wallpaper 5 of the present invention.
Reference numeral 2 is a first layer, and 3 is a foamed second layer. Reference numeral 4 is an aqueous resin adhesive layer provided on the second layer.

[0036]

Example 1 (1) First-layer raw material-containing waste paper pulp 60 wt% Virgin pulp (softwood, hardwood) 10 wt% Polyester (manufactured by Teijin Limited, TT04SD 6.6 dt × 5.5 mm cut) 30 wt% Dry paper strength agent (Manufactured by Japan PMC Co., Ltd.) ^* 0.8 wt% wet paper strength agent (manufactured by Japan PMC Co., Ltd.) ^* 0.6 wt% liquid sulfuric acid band (pH 5.5) ^* 2 wt% Note *: It is a compounding amount with respect to 100 wt%. (2) Second-layer raw material-blended waste paper pulp 63 wt% Virgin pulp (softwood, hardwood) 10 wt% Polyester (manufactured by Teijin Ltd., TT04SD 6.6dt x 5 mm cut) 19 wt% Vinylon (manufactured by Teijin Ltd., LPB107-2 1dt) 3mm cut) 5wt% Foaming agent (Matsumoto Yushi Co., Ltd., Matsumoto Microsphere F-46) 3wt% Dry paper strength agent (Japan PMC Co., Ltd.) ^* 0.8wt% Wet paper strength agent (Japan PMC ( ^* 0.6 wt% liquid sulfuric acid band (pH 5.5) ^* 2 wt% Note *: The chemical compounding amount of ~ is the compounding amount relative to ~ 100 wt%.

A wet sheet was formed from the slurry by using a round steel paper machine for the first layer composition and a long steel paper machine for the second layer composition. The first layer and the second layer were pasted together, sucked, and roll-pressed. After physically removing water to some extent, it was heated and dried at 100 ° C. with a drying dryer to produce a two-layer foam paper.

The physical properties of the two-layer foam paper of Example 1 and a general base paper (white kraft paper) having almost the same thickness as that of the two-layer foam paper were measured,
The measurement results are shown in Table 1.

Each physical property value was measured as follows.

(Basis weight) JIS P8124 "Measurement method of paper grammage"

(Thickness) JIS P8118 "Testing method for thickness and density of paper and board"

(Water immersion elongation) J. TAPPI No. 27 "Method for testing water immersion elongation of paper and paperboard", Method A, immersion time 15 minutes

(Clark Rigidity) JIS P8143 “Clarke stiffness test method for paper by Clark stiffness tester” In addition, since the length of the test piece is insufficient, it is based on TAPPI standard test method T451 “Paper bending property (Clark stiffness)”. Then, a weight was attached to one end of the test piece for measurement.

(Curl degree) J. TAPPI No. 16 "Paper Curl Test Method II"

[0045]

[Table 1]

As is clear from the above results, 2 of the present invention
The layer-foamed paper was excellent in dimensional stability (water immersion elongation), flexibility (Clark stiffness), and curl resistance (curl degree).

Example 2 A water-based resin adhesive (trade name "Aminol", manufactured by Yayoi Chemical Industry Co., Ltd.) wet 180 g / m ^{2 was} applied on the second layer of the two-layer foam paper obtained in Example 1. Then, the wallpaper was prepared.

The above-mentioned wallpaper was used as an interior material and stuck on a wall.
During the construction, it could be attached without curling. Also,
Even after drying, the seams did not open and the seams did not turn up even after drying.

[0049]

INDUSTRIAL APPLICABILITY The two-layer foamed paper of the present invention is excellent in dimensional stability, flexibility and curl resistance, and therefore, wallpaper, fusuma paper,
It is useful as a base paper for exhibition paper and booth paper. Further, the two-layer foamed paper of the present invention is excellent in flexibility, and thus has a characteristic that it is easily embossed and that the formed emboss is hard to disappear.

The wallpaper of the present invention is excellent in dimensional stability, flexibility and curl resistance, and does not impair the production environment and the indoor environment because no organic solvent is used, and is excellent in curl resistance. Therefore, the construction efficiency is improved and the seams do not turn up after construction.

Further, since the wallpaper of the present invention has two layers, it is peeled off from the first layer (upper layer) at the time of re-covering or reworking after construction, so that the base is not damaged and the next re-walling is easy. It has the characteristics of

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a two-layer foam paper of the present invention.

FIG. 2 is a schematic cross-sectional view of the wallpaper of the present invention.

[Explanation of symbols]

1 2 layer foam paper 2 First layer 3 Second layer 4 Water-based resin adhesive layer 5 wallpaper

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4L055 AA02 AA03 AC06 AC09 AF33                       AG99 AH34 AJ01 AJ08 BD17                       BE09 FA16 FA30 GA23

Claims (7)

[Claims] 1. A heat-foaming agent comprising a first layer containing pulp and synthetic fibers as essential components and a second layer on top of which a second layer containing pulp, synthetic fibers and heating foaming agents as essential components is heated and heated. A method for producing a two-layer foam paper, which comprises foaming. 2. The method for producing a two-layer foam paper according to claim 1, wherein the heat-foaming agent is a heat-expandable microcapsule containing a low boiling point hydrocarbon. 3. The method for producing a two-layer foam paper according to claim 1, wherein the synthetic fiber is at least one selected from rayon, acrylic, polyester and vinylon. 4. The method for producing a two-layer foam paper according to any one of claims 1 to 3, wherein the pulp is a mixed pulp of waste paper pulp and virgin pulp. 5. The method for producing a two-layer foam paper according to any one of claims 1 to 4, wherein the first layer further contains a heating foaming agent. 6. A two-layer foam paper produced by the production method according to any one of claims 1 to 5. 7. A first two-layer foam paper according to claim 6.
A wallpaper comprising an aqueous resin adhesive layer provided on the surface of the layer surface or the second layer surface.