JP2000328499A - Low density wallpaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low density wallpaper having excellent embossing finish property and allowing easy perparing work by laminating a surface protecting film composed of a thermoplastic resin onto a specific low-density paper laminated through a heat-melting resin film to a backing paper. SOLUTION: A low-density paper having 0.1-0.5 g/m3 density and >=300 μm thickness and obtained by carrying out wet papermaking of a pulp raw material comprising 10-100 wt.% thermomechanical pulp (TMP), 0-90 wt.% curled fiber and 0-40 wt.% of the other pulp based on total pulp fiber weight and having >=2.3 mm weight-average fiber length of TMP when the above curled fiber content is 0 wt.% is laminated through a heat-melting resin film such as a polyolefin-based film having 10-50 μm thickness to a backing paper and a surface protecting film comprising a thermoplastic resin having 5-20 m thickness onto the above low-density paper to provide the objective low-density wallpaper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall covering material obtained by laminating a backing paper on low-density paper, and more particularly to a wall covering material having excellent embossability and workability.

[0002]

2. Description of the Related Art Up to now, foamed embossed vinyl chloride wallpaper has been widely used as interior decoration material for interior decoration with the upsizing and diversification of living space. Foamable embossed vinyl chloride wallpaper is inexpensive, easy to process such as printability, foamability, embossability, etc., and has excellent design, and many of the general commercial wallpapers are Occupied by this foamed embossed vinyl chloride wallpaper.

However, in the case of foamable embossed vinyl chloride wallpaper, the plasticizer contained in the vinyl chloride resin bleeds to the surface, and the wallpaper surface becomes dirty, and a large amount of harmful gas such as hydrogen chloride gas is generated at the time of fire or waste incineration. It generates black smoke and high heat, polluting the environment. For this reason, the vinyl chloride resin is replaced with an ethylene / vinyl acetate copolymer (JP-A-58-4879), or an amorphous polyester resin is used (JP-A-5-116255).
However, the former has a drawback that generation of odor of the resin is pointed out and that the volume feeling of the foamed embossed / vinyl chloride wallpaper cannot be obtained. The latter is made of paper or non-woven fabric, so that flexibility can be obtained, but there is a drawback that dust and dirt tend to adhere and maintenance and management become difficult.

On the other hand, as a paper wallpaper made of pulp fiber which has been used for a long time, techniques for improving workability are disclosed in Japanese Utility Model Publication No. Sho 61-23240 and Japanese Utility Model Publication No. Sho 61-200.
No. 76, where a surface decorative paper is bonded onto a backing paper via a hot-melt resin extruded from an extruder, and a resin layer interposed between the surface decorative paper and the backing paper. Drying of the construction glue applied to the back side during construction is suppressed, so that the open time after the application of the construction glue can be lengthened.
In Japanese Patent No. 76, a foamable ink is printed on a surface decorative paper, and the foamed ink is foamed to form an uneven surface protection layer.

[0005] However, these paper wallpapers can improve the workability, but cannot provide a paper having the same volume feeling as the foamed embossed / vinyl chloride wallpaper. Therefore,
As a part of wallpaper using a pulp material, the present inventors used a low-density non-woven fabric made of pulp fibers in Japanese Patent Application No. 8-327609, stuck it to a backing paper via a hot-melt resin, A method was proposed in which a printed surface protection film was attached to the surface layer.

[0006] However, this nonwoven fabric wallpaper has good workability and embossability compared to conventional paper wallpaper, but also has a larger embossed volume feel than foamed embossed / vinyl chloride wallpaper. When the nonwoven fabric is crushed and thinned during lamination with the backing paper, the concealment of the construction base is low.

A method has also been proposed in which a heat-expandable microcapsule is added to pulp fiber, and a foamed paper formed and foamed with a wet paper machine is bonded to a backing paper. Although the mixed foamed paper has good embossability, the basis weight of the foamed paper increases,
When the thickness is greatly increased, the wallpaper is hard and the wrinkles during construction are hard to return. Also, since the thermally expandable microcapsules are expensive, the resulting wallpaper is expensive.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a wall covering material which has good workability, has embossability (volume feeling) equal to or higher than that of foamed embossed / vinyl chloride wallpaper, is inexpensive and has high environmental safety. The purpose is to provide.

[0009]

Means for Solving the Problems In developing a wall covering material for interior decoration, the inventors of the present invention have good embossability (volume feeling) which is good in workability and equal to or higher than that of foamed embossed / vinyl chloride wallpaper. As a result of intensive studies to obtain a wall covering material having high environmental safety, the paper is made on a wet paper machine with curled fiber and / or TMP as a main component, and the sheet density is 0.1 to 0.5 g. Bonding low density paper adjusted to not more than / cm ³ and thickness not less than 300 μm to backing paper via a hot-melt resin film, and bonding a surface protective film made of thermoplastic resin on low density paper As a result, the present inventors have found that a wall covering material having both embossability and embossed volume, good workability, and high environmental safety can be obtained, thereby completing the present invention.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the low-density wallpaper according to the present invention, the low-density paper on the front side is made of the same pulp fiber as the backing paper, is bulky and irregular, and has a thin thermoplastic surface. Since it is covered with a resinous surface protection film, it is not easily contaminated like a foamed embossed / vinyl chloride wallpaper, it is flexible and flexible and has a voluminous feel. Since the heat-fusible resin film layer that adheres to the water-impervious waterproof layer forms, the glue does not seep into the low-density paper layer, just like foamed embossed / vinyl chloride wallpaper, and its moisture evaporates from the surface. Open time after application of the application glue (time that can be applied after application of the adhesive) can be taken, making it easier to perform the application.

As the backing paper, those commonly used for wallpaper are used. However, in consideration of the concealing property with respect to the wallpaper application base and the application adhesiveness of the application paste, those having a thickness of 50 to 150 g / m ² , especially wallpaper, are used. In terms of flame retardancy, it is preferable to use a flame retardant backing paper having a flame retardant or an inorganic paper.

The backing paper and the low-density paper are pressed with a hot-melt resin film coated with an adhesive therebetween, and pressed.
Lamination is performed via the film that is melted by heat, or a hot-melt resin film that is melted and extruded from an extruder (T-die extruder) is sandwiched between a backing paper and a low-density paper to be laminated.

As the heat-fusible resin, various heat-fusible resins such as polyester resin, ethylene / vinyl acetate resin, polypropylene resin, polyethylene resin, and attack polypropylene resin are used. In terms of chemical conversion, it is preferable to use a polyolefin resin that emits a small amount of smoke during combustion, and this is the same in the case of a surface protective film. Note that a flame retardant may be kneaded in advance in the polyolefin resin used for bonding. The thickness of the heat-fusible resin film is preferably from 10 μm to 50 μm, and if the thickness is less than 10 μm, a pinhole is formed, and as a moisture-impermeable waterproof layer that suppresses the transfer of moisture in the application paste applied during construction to the surface. The effect of is diminished. If it exceeds 50 μm, the low-density paper wallpaper becomes hard,
It becomes difficult to perform the construction according to the corners or undulations, and furthermore, the flame retardancy of the low density paper wallpaper is hindered.

The bonding between the surface protective film and the low-density paper is performed in the same manner as in the case of the backing paper and the low-density paper. When bonding the hot-melted surface protection film to low-density paper, use an engraving roll (embossing roll) for the pressing roll that presses the hot-melted surface protection film onto low-density paper. It is good to emboss. Also, when bonding using an adhesive,
The adhesive may be applied to the entire surface protective film by a doctor, but in order to facilitate the subsequent embossing, it is preferable to apply the adhesive partially in a dot shape using a gravure roll or the like. Alternatively, the surface protective film may be bonded through a hot-melt resin that is extruded by being hot-melted from the extruder. When the backing paper is bonded to the low-density paper bonded to the surface protection film via the heat-fusible resin film, it is preferable to perform embossing simultaneously with the bonding.

The thickness of the surface protective film is 5 to 20 μm. If it is less than 5 μm, it will be easy to tear during press embossing, while if it exceeds 20 μm, it will be difficult to form sharp (sharp) irregularities in the press embossing, and the irregularities will be hard and the effect of using bulky low-density paper will be lost. Would. Further, the calorific value at the time of combustion increases, and the flame retardancy of the low-density paper wallpaper is hindered.

When a pattern required for surface decoration is printed on a low-density paper wallpaper, it is preferable to print the back surface of the surface protection film facing the low-density paper on the surface protection film. In addition, by performing white solid printing after the pattern printing on the back surface of the film, the concealing property can be further improved and the printing can be sharpened.

The curled fiber used in the low-density paper used in the present invention has an apparent length as compared with the original fiber length, in which deformation such as curl or twist is fixed by chemical bonding due to an intramolecular crosslinking reaction. Pulp fibers whose length has become smaller. Known carded fibers can be used. For example, there are a dry crosslinking method, an aqueous solution crosslinking method, and a substantially non-aqueous solution crosslinking method, and US Pat. Nos. 3,224,926 and 3,241,55, respectively.
No. 3,035,147. The most known crosslinking agents are formaldehyde and formaldehyde adducts.
2 to C8 dialdehyde and C2 to C2 having an acid function
A method of cross-linking the inside of a cellulosic fiber using C8 monoaldehyde (Japanese Patent Publication No. 5-71702) can be used. After adding a cross-linking agent to the pulp fiber, mechanical stirring is performed, followed by fluffing and heat treatment, and when the fiber is fixed while being deformed, a curled fiber having a large curl is obtained.

In the present invention, the wet curl factor is 0.4
A curled fiber in the range of 1.0 to 1.0 is used, and a fiber in the range of 0.5 to 1.0 is preferably used. When the wet curl factor is less than 0.4, the bulkiness becomes small and the density becomes high. On the other hand, if the wet curl factor exceeds 1.0, the fiber strength is reduced due to damage to the pulp fiber caused by strengthening the mechanical treatment when deforming the pulp fiber rather than the effect on the bulkiness. It is not preferable because the occurrence becomes remarkable.

Incidentally, the wet curl factor is an index indicating the degree of deformation of a fiber in a wet state, and the actual fiber length (L) of a curled fiber after immersion in pure water at room temperature for 24 hours.
A) and the maximum projected length of the fiber (the length LB of the longest side of the rectangle surrounding the fiber) was measured using a microscope, and [[LA / L
B) -1] This is a calculated value. When the wet curl factor is in the range of 0.4 to 1.0, the pulp fiber is bent with a considerable amount of deformation, and the fiber is rigid because of the cross-linking treatment. The paper made has a low density.

Further, the carded fiber preferably has a water retention value indicating the ability to retain water of 10 to 80%, and more preferably 25 to 60%. If the water retention is less than 10%, the (-OH) of the cellulose molecule is too small to weaken the fiber bond, and if it exceeds 80%, the curl returns in a short time in a wet state, which is not preferable. By the way, the water retention degree is 3000 G for 15 minutes for the fiber in the wet state.
Is defined as a value (%) expressed as an amount per 1 g of absolutely dried fiber, which is the amount of water held by the fiber after dehydration by centrifugal force of JAPAN TAPPI No. 26-7
8. This value is based on the hydroxyl group (-
OH), that is, the hydrogen bonding ability between fibers.

However, in these pulp fibers having cross-linking, hydroxyl groups (-OH) of cellulose molecules are reduced by the cross-linking treatment, and therefore, the hydrophilicity of such fibers is smaller than that of pulp not subjected to the cross-linking treatment. ,
The ability to form interfiber bonds is low, making papermaking difficult.
When the sheet is made of only the curled fiber, the sheet strength after drying is extremely low. In JP-A-9-41300, it is essential to mix fine fibers together with curled fibers.

TMP in the present invention is an abbreviation of thermomechanical pulp. In the pulping method by steam heating treatment and refining treatment, the state of fiber opening can be controlled by heating, pressurizing and steaming conditions. it can. In TMP used for papermaking, the chip is at a temperature not exceeding the glass transition point of lignin, that is, lignin is softened,
It is heated to a temperature that exists as a glass state. In this case, the fibers are mainly cleaved between the primary membrane and the outer layer of the secondary membrane by refining, and the fiber surface becomes rough, resulting in a pulp containing many hydrophilic long fibers. This results in a bulky sheet. There is also a CTMP method in which a chip is chemically treated and then refined under pressure. Some BCTMPs have been bleached. The species of tree used as a raw material may be coniferous or broadleaf. However, in order to obtain a bulky sheet with TMP alone, it is preferable to use softwood having a long fiber length as a raw material. In order to obtain a bulky sheet, it is more preferable that the refining in the pulp manufacturing process is of the primary refining only type.

Depending on the desired sheet properties, TMP may be used alone or other pulp may be mixed. Other pulp may be NBKP, LBKP, other non-wood pulp such as wood pulp, linter pulp, hemp pulp, or fine fiber such as microfibril.
It is preferable that the curled fiber and TMP are used without being beaten without being beaten, but other pulp may be beaten or not beaten, and may be appropriately selected. The pulp content is as follows: density: 0.1 to 0.5 g / cm ³ and thickness: 300 μm
If it is above, there is no particular limitation. However, if the blended amount of the curled fiber exceeds 90% by weight, not only papermaking becomes difficult, but also sheet strength is hardly developed, so that the curled fiber content is 90% by weight or less. It is good to make paper.

When TMP is used as a main component without blending curled fiber, the density is 0.1 to 0.5 g / cm.
^In order to secure ³ , it is preferable to use it without beating, but even after beating, it is preferable that the fiber length of TMP is not less than 2.3 mm in weight-weighted average. In general, when TMP is used, it is a standard method to perform sufficient beating in order to develop sheet strength. However, in the present invention, when curled fibers are not blended, if the fiber length of TMP is less than 2.3 mm, the TMP should be 0.3 mm. It is difficult to develop a density of 5 g / cm ³ or less, and is not suitable as low-density paper. In addition, more preferably, when the curled fiber is not blended,
When 70% by weight or more of TMP having a weight-weighted average of 2.3 mm or more is blended, a density of 0.5 g / cm ³ or less is easily exhibited.

When the density of the low-density paper is less than 0.1 g / cm ³ , the sheet strength and the interlayer strength are generally low, and the paper is easily crushed at the time of lamination and easily peeled from the interlayer of the low-density paper at the time of embossing. If the thickness is less than 300 μm, a voluminous embossed pattern cannot be obtained. Gurley stiffness in the flow direction (longitudinal direction) (TAPPI T543om
-94) is preferably 40 mN or less, and when it exceeds 40 mN, the resulting low-density paper wallpaper is hard and easily wrinkled when wound around a 2-inch paper tube for storage. In addition, there is a problem that the outer corner and the inner corner of the wall in the construction are not clearly determined. Therefore, the basis weight of the low-density paper is not particularly limited and can be appropriately selected as long as the paper quality is satisfied. However, even if the total wallpaper weight is too heavy,
Since it may have an adverse effect on flame retardancy, it is preferably 5
It is good to make paper in the range of 0 to 150 g / m ² .

Examples of papermaking chemicals include sizing agents, fixing agents, paper strength agents, wet paper strength agents and the like used in ordinary papermaking. As the sizing agent, there are internal sizing agents such as alkyl ketene dimer, styrene acrylic resin, and rosin.
As the fixing agent, a chemical such as a cationized starch or a sulfate band is selected. Examples of paper strength agents and wet strength agents include polyacrylamide resins, polyamide epichlorohydrin resins, and the like. Of course, the present invention is not limited to the chemicals. Further, since the curled fiber has low hydrophilicity, it is difficult to uniformly disperse the same, and a chemical such as a surfactant may be added as a disintegration / dispersion aid.

The raw material / slurry of the above-mentioned materials is made into a paper by a conventional method. The papermaking may be any of ordinary fourdrinier paper machine, circular net paper machine, short net paper machine, inclined paper machine, various combination paper machine, and the like, and is not particularly limited. Drying may be performed by any of ordinary multi-cylinder dryers, Yankee dryers, through dryers, etc., and is not particularly limited. In order to further reduce the density, it is preferable to reduce the pressing pressure as much as possible.

The low-density paper thus obtained is impregnated with various polymer aqueous solutions by off or on machine (size press),
Coating and spraying may be used. The impregnating chemical can be appropriately selected according to the required characteristics. For example, natural or synthetic resins such as polyvinyl alcohol, starch methylolated melamine, SBR latex, and NBR latex are impregnated to improve surface strength and enhance embossability.
To impart flame retardancy, a water-soluble flame retardant such as guanidine phosphate or guanidine sulfamate is impregnated and coated.

[0029]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. In the following, “%” indicates “% by weight”.

Example 1 A curl having a wet curl factor of 0.65 and a water retention of 50%
Dofiber (trademark HBA-FF, Wearhauser, USA)
90% (not beaten) and NBKP (Housand)
Beaten to 450mlcsf) 10% mixed, papermaking chemical
At the next absolute dry weight percent. Polyacryl as a paper strength agent
Luamide resin (trade name: Polystron 117, Arakawa Chemical)
0.3%, Alkyl Ketenda
Immer (trademark: Size Pine K287, Arakawa Chemical Co., Ltd.)
0.1%, cationized starch as a fixing agent
(Trademark: Soldine CP-10A, manufactured by Daiwa Chemical Industry Co., Ltd.)
0.8%, polyamide resin (trademark: A
Rapix 125, Arakawa Chemical Industries) 0.3%
You. From the stock thus prepared, use a real short netting machine
100g / m ^TwoWas made. Drying is multi-cylinder
Performed at 110 ° C. using a layerer. Low density paper obtained
Was measured for thickness, density and Gurley stiffness.

Next, an ethylene / vinyl alcohol copolymer resin film gravure-printed on one side of this low-density paper (trade name: EVAL HF-M, thickness 12 μm, manufactured by Kuraray Co., Ltd.)
Are bonded together via a molten resin film (thickness: 20 μm) of a low-density polyethylene resin (Mirazon 16P, manufactured by Mitsui Petrochemical Industries, Ltd.) extruded by an extrusion laminator, and at the same time, the other surface of the low-density paper is difficult to adhere to. A low-density polyethylene resin (Mirazon 16P, manufactured by Mitsui Petrochemical Co., Ltd.) extruded by extrusion lamination with a fired backing paper (basis weight 60 g / m ² ) through a molten resin film (thickness 30 μm). Make a density paper wallpaper.

The raw wallpaper was passed through a heated embossing roll at 100 ° C. to obtain a low-density paper wallpaper. The thus obtained low-density paper wallpaper was applied to a wall surface using a starch-based application paste, and the workability was evaluated.

Measurement Method Thickness: The thickness was measured under a load of 2 KPa according to JIS L 1906. Density: The density was calculated according to JIS P8118. Gurley stiffness: TAPP as a measure of sheet flexibility
Gurley stiffness was measured according to IT543m-94. Embossing property: A good low-density paper wallpaper having good embossing and volume was evaluated as ○. A sample that was not embossed well and that lacked a sense of volume were rated as x. Workability: Try installing low-density paper wallpaper, how to wrinkle,
Observations were made on how the outgoing corners and inset corners were determined, open types, etc., and those with good overall workability were rated as good, and those with poor workability were rated as poor.

Example 2 In the same manner as in Example 1 except that the curled fiber of Example 1 was mixed with TMP (manufactured by Pampak, Radiatapine 100%, unbeaten) and 50% of curled fiber and 50% of TMP were used. The low-density paper was made and laminated to obtain a low-density paper wallpaper.

Example 3 A low-density paper wallpaper was obtained by making and bonding low-density paper in the same manner as in Example 1 except that the TMP in Example 1 was changed to 100%. The weight-weighted average fiber length of TMP was 2.7 mm. (Measured by Kayani fiber length measuring device)

Comparative Example 1 A low-density paper was obtained by making and bonding low-density paper in the same manner as in Example 1 except that the curled fiber in Example 1 was changed to 100%.

Comparative Example 2 The TMP of Example 3 was beaten by DDR, the weight-weighted average fiber length was 2.2 mm, and the TMP was 100%. A density paper wallpaper was obtained.

Comparative Example 3 A low-density paper having a basis weight of 250 g / m ² was prepared by blending 50% of curled fiber and 50% of TMP in Example 2.
Papermaking and bonding were performed in the same manner as in Example 1 to obtain a low-density paper wallpaper.

Comparative Example 4 Example 1 was repeated except that the TMP of Example 3 was set to 100%, and heat-expandable microcapsules (Expancel 007, manufactured by Nippon Philite Co., Ltd.) were added as expandable particles at 10%, followed by papermaking. Papermaking and bonding were performed in the same manner as in Example 1 to obtain a low-density paper wallpaper.

Comparative Example 5 NBKP (manufactured by Howsand, unbeaten) was sprayed from a dry pulp mat former to form a layered mat having a basis weight of 50 g / m ² , and a non-crosslinked ethylene vinyl acetate emulsion resin (Sumitomo Chemical Co., Ltd.) An aqueous solution of EVA (manufactured by Kogyo Co., Ltd.) was sprayed to produce a pulp nonwoven fabric having a basis weight of 75 g / m ² . Using this nonwoven fabric, it was bonded in the same manner as in Example 1 to obtain a nonwoven fabric wallpaper. Table 1 shows the evaluation results of the examples and the comparative examples.

[0041]

[Table 1]

As is clear from Table 1, the low-density paper wallpaper produced by using low-density paper of which density and stiffness are adjusted by blending curled fiber and TMP within a predetermined amount has a large volume feeling in emboss. The workability was good.
In particular, in Examples 1 and 2, the embossed volume was comparable to foamed embossed / vinyl chloride wallpaper.

On the other hand, curled fiber 100%
In this case, although the density is low, the papermaking property is poor and the strength is low, so that it is peeled between layers of the low-density paper during embossing (Comparative Example 1). When the density of the sheet exceeds 0.5 g / cm ³ , the embossed volume feeling is insufficient (Comparative Example 2). When the rigidity of the low density paper exceeds 40 mN,
The flexibility of the resulting low-density paper wallpaper is insufficient, causing wrinkles when wound on a roll during storage, and the corners of the wall at the time of construction are not clearly determined (Comparative Example 3). On the other hand, low-density paper containing heat-expandable microcapsules has good embossing properties, but hardly returns wrinkles at the time of breaking during construction (Comparative Example 4). The wallpaper using the pulp non-woven fabric is liable to be crushed at the time of lamination and the embossing is insufficient in volume (Comparative Example 5).

[0044]

As described above, according to the present invention,
It has a density of 0.1 to 0.5 g / cm ³ and a thickness of 300 based on carded fiber and / or TMP.
Low-density paper wallpaper with a surface protection film and a backing paper bonded to each other using low-density paper with a Gurley stiffness of 40 mN or less in the flow direction is 40 μm or more. Equipment can be provided. In addition, unlike foamed embossed vinyl chloride wallpaper, it also has environmental safety that hydrogen chloride gas is not generated during combustion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuhiro Sano 300 Ogaki Paper Manufacturing Co., Ltd., Fuji-shi, Shizuoka Prefecture (72) Inventor Satoshi Takahashi 5-12-8 Ginza, Chuo-ku, Tokyo Oji Paper 1 Building F-term (reference) 4L055 AC03 AF09 AF46 AG59 AG64 AG89 AJ02 AJ07 BE13 BE14 BE15 EA04 EA08 EA16 FA11 FA16 FA22 GA23

Claims (3)

[Claims] 1. A low density paper thickness pulp fibers through a hot-melt resin film to the backing paper in papermaking has been density 0.1 to 0.5 g / cm ³ by a wet paper machine as material is 300μm or more A low-density paper wallpaper characterized in that a surface protective film made of a thermoplastic resin is bonded on the low-density paper. 2. The low-density paper wallpaper according to claim 1, wherein the low-density paper has the following structure. (1) TMP 10 to 100% by weight based on the total pulp fiber weight (2) Curled fiber 0 to 90% by weight (3) Other pulp 0 to 40% by weight 3. The low-density paper wallpaper, wherein when the low-density paper does not contain curled fibers, the weight average fiber length of the TMP is 2.3 mm or more.