JP2015124448A - Lining paper for wallpaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lining paper for a foamed wallpaper excellent in peeling suitability when the wallpaper is peeled from a wall surface, the wet tensile strength of the lining paper, the dimensional change rate in water of the lining paper, the curling property of the lining paper, and the mutual peeling property of the lining paper with a wallpaper.SOLUTION: The lining paper for a wallpaper produced from a paper substrate containing pulp is produced by papermaking the pulp in which a wet paper strengthening agent is contained in a content of 0.5 mass%-3.0 mass%; a rosin sizing agent is contained in a content of 0.05 mass%-0.3 mass%; kaolin is contained in a content of 5 mass%-25 mass%; and a yield improver is contained in a content of 0.001 mass%-0.035 mass%, and the lining paper has an aspect ratio of the tensile strength measured according to JIS P 8113 (2006) of 1.0-2.5 and a sizing degree measured by the Stockigt method specified in JIS P 8122 (2004) of 1-20 second(s).

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing paper for wallpaper used for foamed wallpaper and the like, and in particular, a backing paper for wallpaper excellent in peelability when peeling the wallpaper from the wall surface, wet tensile strength of the backing paper, underwater dimensional stability, curl, and peelability. About.

Foamed wallpaper such as vinyl foamed wallpaper, paper foamed wallpaper, and olefin foamed wallpaper is mainly composed of a two-layer structure of an upper layer that imparts designability and a backing paper that supports the upper layer and imparts workability. These foamed wallpaper is pasted on the wall with water-based glue such as starch or vinyl acetate at the time of construction, but the water in the glue is absorbed by the backing paper in this gluing process, and the foamed wallpaper becomes soft or lining. Paper may stretch due to increased moisture. Further, due to this, there are problems such as the occurrence of curling becomes large, the work of sticking the foamed wallpaper to the wall surface becomes difficult, and the wallpaper after the sticking tends to curl. In addition, when the glue dries, the backing paper shrinks, and when performing sticking with good construction productivity, there is a problem (gap) that creates a gap in the joint portion between adjacent bonded wallpapers. There were drawbacks such as impaired designability.
For this reason, the backing paper made by making the drying part of the paper making process dry with a so-called Yankee dryer is used as the backing paper for foamed wallpaper which is difficult to curl even when glued and the dimensional stability is improved. (Patent Document 1, Patent Document 2).

Also, a backing paper has been proposed that has less fluffing of the backing paper, excellent printability, and good peelability when peeling wallpaper from a wall surface (Patent Document 3).
However, in these inventions, in addition to the peelability when peeling the wallpaper from the wall surface, no consideration is given to a technique that simultaneously satisfies wet tensile strength, underwater dimensional stability, curl, and phase peelability. Was not enough.

JP 2005-82894 A JP 2007-92223 A JP 2009-242982 A

  Accordingly, an object of the present invention relates to a backing paper for wallpaper, and provides a backing paper for wallpaper that is excellent in peelability when peeling the wallpaper from the wall surface, wet tensile strength of the backing paper, underwater dimensional stability, curl, and peelability. There is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have included kaolin, a wet paper strength agent, and a rosin sizing agent as fillers in a specific range, and have a tensile strength aspect ratio and size. It has been found that good results can be obtained when the degree is controlled, and the present invention has been completed.

That is, the present invention includes the following inventions.
(1) In the backing paper for wallpaper which consists of a paper base material containing a pulp, 0.5-3.0 mass% of wet paper strength agents, 0.05-0.3 mass% of rosin sizing agents, Paper is made by containing 5 to 25% by mass of kaolin and 0.001 to 0.035% by mass of a yield improver, and the aspect ratio of tensile strength measured according to JIS P 8113: 2006 is 1.0 to 2. 5. A backing paper for wallpaper characterized in that the sizing degree of the Steecht method measured in accordance with JIS P 8122: 2004 is 1 to 20 seconds.

(2) The backing paper for wallpaper according to (1), wherein the Canadian standard freeness (CSF) measured according to JIS P 8121-2012 of the pulp is 400 to 600 ml.

(3) JAPAN TAPPI paper pulp test method no. 27: The backing paper for wallpaper according to (1) or (2), wherein the underwater elongation measured in accordance with 27: 2000 is 2.0% or less.

(4) The backing paper for wallpaper according to any one of (1) to (3), wherein the paper substrate has a basis weight of 60 to 100 g / m ² .

  The backing paper for wallpaper of the present invention is excellent in peelability when peeling the wallpaper from the wall surface, wet tensile strength of the backing paper, underwater dimensional stability, curl, and phase peelability, even though expensive materials are not used. A backing paper for wallpaper.

  In the backing paper for wallpaper of the present invention, it is necessary to contain the wet paper strength agent in the range of 0.5 to 3.0% by mass with respect to the paper base material. It is preferable to make it contain 0.5 mass%, More preferably, it is 0.8-2.0 mass%. When the content of the wet paper strength agent is less than 0.5% by mass, the underwater dimensional change rate and curl are large, and the workability at the time of pasting the wallpaper deteriorates. When the content of the wet paper strength agent exceeds 3.0% by mass, the dimensional change rate in water is small, but the operational problem that the disaggregation property of the waste paper deteriorates occurs.

  In addition, since a paper interlayer strength becomes high by containing a wet paper strength agent in a relatively higher ratio than usual, it is possible to improve re-peelability when the wallpaper is peeled from the wall surface at the time of replacement.

  Examples of the wet paper strength agent used in the present invention include polyamide / epichlorohydrin, polyamine / epichlorohydrin, epoxy resin, melamine resin and the like, and in particular, polyamide / epichlorohydrin or polyamine / epiamine. Preference is given to using chlorohydrin.

It is necessary to contain the rosin sizing agent internally added in the present invention at a lower ratio than usual, that is, 0.05 to 0.3% by mass, and in particular, 0.07 to 0.25% by mass. Is more preferable, and 0.08 to 0.22 mass% is more preferable. When the content of the rosin sizing agent is less than 0.05% by mass, the water permeability becomes excessively high, the elongation in water and the curl become excessively large, and the workability at the time of pasting the wallpaper deteriorates.
On the other hand, even if the content of the rosin sizing agent exceeds 0.3% by mass, the degree of sizing does not improve any more, which is uneconomical and causes stains on the paper machine. The rosin sizing agent can be used for both acidic and neutral use.

  In order to improve the opacity, the paper base material used for the wallpaper backing paper of the present invention needs to contain 5 to 25% by mass of kaolin as a filler, but 7 to 20% by mass is included. Preferably, it is 8-18 mass%. When the content of kaolin is less than 5% by mass, the opacity becomes insufficient, and the peelability at the time of peeling the wallpaper from the wall surface at the time of replacement becomes insufficient. Conversely, when the kaolin content exceeds 25 mass%, the wet tensile strength becomes insufficient. Other than these, delaminated kaolin, heavy calcium carbonate, light calcium carbonate, light calcium carbonate-silica composite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, water You may use together inorganic fillers, such as aluminum oxide, calcium hydroxide, magnesium hydroxide, and zinc hydroxide, and organic fillers, such as urea-formalin resin, a styrene resin, and a phenol resin, in the range which does not inhibit a desired effect.

  By the way, when the wallpaper is replaced, it is important that when the wallpaper is peeled off, the space between the backing papers is uniformly broken and the wall surface is not made uneven. By using a flat kaolin as a filler for the backing paper, the inter-sheet strength of the backing paper can be lowered with a small amount of addition, and the wallpaper can be peeled uniformly.

Examples of the yield improver used in the present invention include polyacrylamide compounds, polyethylene glycol compounds, and polyvinylamine compounds, with cationic polyacrylamide compounds being particularly preferred. When kaolin is used as the filler, the overall yield decreases and the productivity tends to decrease. Therefore, an appropriate retention agent can be appropriately selected in order to maintain the productivity.
The content of the yield improver needs to be 0.001 to 0.035% by mass, preferably 0.005 to 0.030% by mass, and preferably 0.008 to 0.020% by mass.

  The paper substrate used for the wallpaper backing paper of the present invention includes softwood bleached kraft pulp (NBKP), hardwood bleached kraft pulp (LBKP), groundwood pulp (GP), thermomechanical pulp (TMP), chemithermo. Paper is made from a slurry prepared by mixing mechanical pulp (CTMP), deinked pulp (DIP), etc., alone or as appropriate.

  In the present invention, it is preferable to adjust the freeness (Canadian standard CSF) measured according to JIS P 8121-2012 of the pulp to be used to 400 to 600 ml. The freeness of the pulp may be adjusted to the above range by beating at least one kind of pulp. When two or more types of pulp are used, the pulps beaten separately may be mixed to make the above range, or the premixed pulp may be beaten and adjusted to the above range. When the freeness of the pulp is lower than 400 ml, the elongation when the wallpaper is constructed with aqueous glue increases, and the shrinkage during drying also increases. ) Is undesirably large. When the freeness of the pulp is higher than 600 ml, the paper strength is lowered, so that the wet strength is lowered and fuzzing is likely to occur on the substrate, which is not preferable.

  Further, the backing paper for wallpaper of the present invention uses a dry paper strength agent, a sulfuric acid band, a dye, a pigment, etc. as an internal additive other than rosin sizing agent and wet paper strength agent, as long as the quality is not affected. be able to.

  The backing paper for wallpaper of the present invention can be produced by a known paper machine. The paper making conditions are not particularly limited. As the paper machine, a known machine such as a long net paper machine, a twin wire paper machine, or a circular net paper machine can be appropriately used.

  In order to obtain the desired backing paper for wallpaper, the ratio of the longitudinal direction and the transverse direction (aspect ratio) of the tensile strength measured according to JIS P 8113: 1998 of the substrate is required to be 1.0 to 2.5. However, it is preferably 1.3 to 2.2, more preferably 1.5 to 2.0. When the aspect ratio of the tensile strength exceeds 2.5, curling is likely to occur, and swelling and wrinkles after gluing are likely to occur. Conversely, when the aspect ratio of the tensile strength is less than 1.0, industrial production is difficult and the operability during papermaking decreases.

As a method for controlling the aspect ratio of the tensile strength to 1.0 to 2.5, for example, a method for appropriately adjusting the jet / wire ratio at the time of papermaking, a method for appropriately adjusting the L / b value of the head box (L is the protruding length of the lower lip with respect to the upper lip of the slice lip, and b is the opening degree of the slice.), A method of increasing the shaking strength of wire shaking, a method of appropriately selecting pulp raw materials and beating conditions Etc. Here, the jet / wire ratio is the ratio of the speed of the raw material ejected from the head box, that is, the speed of the slice jet and the speed of the wire. Generally, the jet / wire ratio is sometimes expressed as a J / W ratio.
Among these, the aspect ratio of the tensile strength of the base material is 1.0 to 2.5 by making paper under the conditions of 20 to 80 for the shaking strength of the wire and 0.950 to 1.050 for the jet / wire ratio. Therefore, it is possible to obtain a backing paper for wallpaper having excellent texture and curling.
Regarding shaking, TAPPI (1966) Vol. 49, no. No. 10 discloses the relationship between the formation of the long paper machine and the shaking strength, and the shaking strength is defined by the following general formula 1.

Formula 1 I = F ² × A / S
I: Shaking strength [ ² times / minute]
F: Frequency [times / minute]
A: Amplitude [inch]
S: Paper machine speed [feet / min]

Moreover, it is necessary to set the Steecht method sizing degree of the backing paper for wallpaper of the present invention according to JIS P 8122 to 1 to 20 seconds, preferably 1 to 15 seconds, and preferably 1 to 10 seconds. It is more preferable. If the Steecht method sizing degree is less than 1 second, there is a problem that the rate of change in water becomes too large and the curl becomes too large. On the other hand, when the Steecht method sizing degree exceeds 20 seconds, the phase peeling property becomes insufficient.
The wallpaper is affixed with water-based glue at the time of construction, folded with the glue side inside, left on the wall for a while, and then the wall is pasted. Need a lot of time. The curing time at the time of leaving is called open time, and when it is left beyond this open time, a phenomenon called phase peeling tends to occur. This delamination refers to a phenomenon in which the backing paper of the folded wallpaper sticks to each other due to drying of the glue, and the paper layer is peeled off.
The lower the sizing of the backing paper, the more easily the water-based glue soaks into the backing paper, and the moisture of the glue is less likely to evaporate.

The basis weight of wallpaper backing paper of the present invention is preferably 50 to 120 / ^{m 2,} and more preferably 60 to 100 / ^{m 2.} If the basis weight is less than 50 g / m ² , the strength is low, and there is a possibility that paper breakage is likely to occur during processing. On the other hand, if the basis weight exceeds 120 g / m ² , curling may increase.

The backing paper for wallpaper of the present invention produced as described above preferably has a Canadian standard freeness (CSF) of 400 to 600 ml when re-disaggregated. If the Canadian freeness is less than 400ml when re-disaggregated, the wall paper product will be stretched when applied with water-based glue, and the shrinkage during drying will increase. Undesirably, the opening (gap) of the wallpaper becomes large.
On the other hand, if the Canadian freeness is higher than 600 ml at the time of re-disaggregation, the paper strength becomes low, which is not preferable because fluffing tends to occur on the base material. In addition, when the backing paper for wallpaper contains a filler, the freeness when re-disaggregated from the freeness of the pulp alone is lowered, so the Canadian standard freeness of the pulp used alone is 400 ml to 600 ml. There is no need to become.

  The paper interlayer strength of the wallpaper backing paper of the present invention is preferably in the range of 10 to 40 N / m, and more preferably 12 to 30 N / m. When the paper interlayer strength is less than 10 N / m, the wallpaper backing paper is affixed to the wall, and then the paper backing layer tends to sag, which is not preferable. If it exceeds 40 N / m, the strength between the paper layers becomes too strong, and it is not preferable because the work efficiency decreases, for example, it is difficult to peel off when it is peeled off after being attached to the wall, and the upper resin layer is easily cut off.

  In addition, the backing paper for wallpaper of the present invention preferably has an underwater elongation of 2.0% or less, more preferably 1.8% or less, from the viewpoint of curling prevention and opening prevention. More preferably, it is 5% or less. In addition, the elongation in water is the value of JAPAN TAPPI paper pulp test method No. It is a value measured according to 27: 2000.

  A decorative layer is provided on the upper layer of the wallpaper backing paper of the present invention to obtain a wallpaper. As wallpaper, for example, vinyl wallpaper provided with a vinyl layer as a decorative layer, olefin wallpaper provided with an olefin layer, fabric wallpaper provided with a fabric layer, paper wallpaper provided with a paper layer, inorganic wallpaper provided with an inorganic layer, etc. Wallpaper products. In any case, after providing a layer to be a decorative layer, printing or foaming or embossing is performed as necessary to form a decorative layer.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
About backing paper for wallpaper produced in Examples and Comparative Examples, peelability when peeling wallpaper from wall surface, tensile strength, wet tensile strength, elongation in water, disintegration, curl, steecht method Size, peelability, filler yield, and texture were evaluated.

<Peel aptitude>
A 50 μm polyester laminate film was laminated on one side of the backing paper to obtain a strip-shaped sample having a flow direction of 5 cm and a width direction of 11 cm. The wallpaper paste is applied to the backing paper side of this sample at a coating amount of 120 g / m ² using wallpaper construction paste (manufactured by Yayoi Chemical Industry Co., Ltd., trade name: “Lure Mild”). The paste-coated surface was bonded to a gypsum board using a roller to obtain a peel suitability evaluation sample.
The peel aptitude evaluation sample was held at 23 ° C. and 50% RH for 24 hours, and then the peel aptitude evaluation sample was peeled off from the gypsum board, and the wall condition was evaluated according to the following criteria.
○: The backing paper is uniformly peeled between the papers, and no irregularities are seen on the wall surface.
×: The backing paper is peeled off unevenly (breaking, etc.).

<Tensile strength>
About the sample cut | judged in width 15mm x length 250mm, based on JISP8113: 2006, the tension | tensile_strength of the backing paper for wallpaper was measured by setting the space | interval of a holding tool to 180 mm, and displayed it in kN / m unit. The tensile strength was measured in the longitudinal direction and the transverse direction of the paper, and the aspect ratio was evaluated.

<Wet tensile strength>
The sample cut into 15 mm in the flow direction and 250 mm in the width direction was dried by heating at 110 ° C. for 10 minutes and then immersed in water at 20 ° C. for 10 minutes. Excess water on the surface of the sample was wiped off with filter paper, and the tensile strength of the backing paper for wallpaper was measured according to JIS P 8113: 2006, with the interval between the grips being 180 mm, and displayed in kN / m units. Evaluation was performed according to the following criteria.
A: 0.4 or more B: 0.35 kN / m or more and less than 0.4 X: 0.3 kN / m or less

<Underwater elongation>
As an index of dimensional stability in water, JAPAN TAPPI paper pulp test method No. 27: 2000, the underwater elongation was measured and evaluated according to the following criteria.
◎: 1.8% or less ○: 1.9% or more and 2.0% or less ×: 2.1% or more

<Disaggregation>
JIS P 8209: 1994 Using a standard disintegrator shown in the method for adjusting handsheets for pulp testing (using JAPAN TAPPI standard disintegrator: 3000 rpm) Was added in an amount of 3%, pH was adjusted to 8.5 with dilute sodium hydroxide aqueous solution, and disaggregation was performed at 30 ° C. for 30 minutes. Evaluation was visually judged according to the following criteria.
○: Completely disaggregated ×: Undissolved portion

<Curl>
The backing paper sample was 10 cm in the flow direction and 10 cm in the width direction, and a 50 μm polyester laminate film was laminated on one side of the backing paper for wallpaper to obtain a 10 cm × 10 cm curl evaluation sample. The curl evaluation sample was immersed in water at 23 ° C. for 10 minutes, then pulled up from the water, and the curl state was visually evaluated according to the following criteria.
A: There is no warping. O: A slight warping was observed.
X: A large warp was observed.

<Stechicht method size>
In accordance with JIS P 8122: 2004, the Steecht method sizing degree of the backing paper was measured.

<Phase peelability>
The backing paper sample was a strip of 5 cm in the flow direction and 11 cm in the width direction, and a polyester laminate film of 50 μm was laminated on one side of the backing paper to obtain a sample of 5 cm × 11 cm. After applying the coating paste for wallpaper (made by Yayoi Chemical Industry Co., Ltd., trade name: “Lure Mild”) to the backing paper side of this sample at a coating amount of 120 g / m ² , paste Folded with the surface inside, left at room temperature, peeled off about 30 mm after a predetermined time, and observed whether the paper layer was torn or not. The time during which the paper layer was not broken was measured and evaluated according to the following criteria.
○: 3 hours or more ×: less than 3 hours

<Filling yield>
Pulp slurry prepared by adding internal chemicals and filler to a solid content concentration of 0.25% is uniformly dispersed with a square sheet machine (manufactured by Kumagai Riki Kogyo Co., Ltd.). A filler yield evaluation sample was formed on top.
The ash content of the sample was measured, and the filler yield was calculated using the following formula. Evaluation was performed according to the following criteria.
Calculation formula: Filler yield (%) = Amount of ash in filler yield evaluation sample / Amount of added filler × 100
○: 70% or more ×: less than 70%

<Guide>
Lined paper samples were placed one by one on the Schaukasten and visually evaluated according to the following criteria.
○: Uniform formation ×: Non-uniform formation

<Example 1>
The papermaking pH is 4.5 in pulp slurry containing 80 parts by mass of hardwood bleached kraft pulp (Canadian standard freeness (CSF): 450 ml) and 20 parts by mass of softwood bleached kraft pulp (CSF: 500 ml). The sulfuric acid band was added to 0.5 mass%. Next, a rosin sizing agent (trade name: “Size Pine N775”, solid content concentration 50%, manufactured by Arakawa Chemical Industries, Ltd.) is added in an amount of 0.1% by mass in terms of solid content per dry pulp weight, and further, Polyamide-epichlorohydrin resin (trade name: “ARAFIX 255”, solid concentration 25%, manufactured by Arakawa Chemical Industries, Ltd.) as a wet paper strength agent was added in an amount of 1.0% by mass in terms of solid content. Furthermore, 0.01% by mass of cationic polyacrylamide (trade name: “Keith Rock RP401L”, manufactured by Kyowa Sangyo Co., Ltd.) as a yield improver and kaolin (trade name: “UW90”, manufactured by BASF Corp.) as a filler (volume) (Average particle diameter: 2.6 μm, aspect ratio: 10.0) was added so as to be 10% per the dry mass of pulp, paper was made with a jet / wire ratio set to 0.970, and a basis weight of 70 g / A m ² backing paper for wallpaper of the present invention was produced.

<Example 2>
In Example 1, Example 1 was used except that 70 parts by mass of hardwood bleached kraft pulp (Canadian standard freeness (CSF): 550 ml) and 30 parts by mass of softwood bleached kraft pulp (CSF: 750 ml) were used. The wallpaper backing paper of the present invention was produced in the same manner as described above.

<Example 3>
Example 1 in Example 1 except that 80 parts by mass of hardwood bleached kraft pulp (Canadian standard freeness (CSF): 350 ml) and 20 parts by mass of softwood bleached kraft pulp (CSF: 450 ml) were used. The wallpaper backing paper of the present invention was produced in the same manner as described above.

<Example 4>
In Example 1, Example 1 except that 80 parts by mass of hardwood bleached kraft pulp (Canadian standard freeness (CSF): 450 ml) and 20 parts by mass of softwood bleached kraft pulp (CSF: 500 ml) were used. The paper was made in the same manner as above to produce a wallpaper backing paper of the present invention having a basis weight of 110 g / m ² .

<Example 5>
In Example 1, Example 1 except that 80 parts by mass of hardwood bleached kraft pulp (Canadian standard freeness (CSF): 450 ml) and 20 parts by mass of softwood bleached kraft pulp (CSF: 500 ml) were used. The paper was made in the same manner as above to produce a backing paper for wallpaper of the present invention having a basis weight of 50 g / m ² .

<Comparative Example 1>
In Example 1, paper making was performed in the same manner as in Example 1 except that the wet paper strength agent was changed to 4% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 2>
In Example 1, paper making was performed in the same manner as in Example 1 except that the wet paper strength agent was changed to 0.3% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 3>
In Example 1, paper was made in the same manner as in Example 1 except that the rosin sizing agent was changed to 0.5% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 4>
In Example 1, paper was made in the same manner as in Example 1 except that the rosin sizing agent was changed to 0.01% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 5>
In Example 1, paper was made in the same manner as in Example 1 except that kaolin was changed to 4% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 6>
In Example 1, paper was made in the same manner as in Example 1 except that kaolin was changed to 26% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 7>
In Example 1, paper was made in the same manner as in Example 1 except that the yield improver was changed to 0.05% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 8>
In Example 1, paper was made in the same manner as in Example 1 except that the yield improver was changed to 0.0005% by mass to produce a backing paper for wallpaper having a basis weight of 70 g / m ² .

<Comparative Example 9>
In Example 1, paper making was performed in the same manner as in Example 1 except that the jet / wire ratio was 0.920, and a backing paper for wallpaper having a basis weight of 70 g / m ² was produced.

<Comparative Example 10>
In Example 1, paper was made in the same manner as in Example 1 except that the jet / wire ratio was 1.025, and a wallpaper backing paper having a basis weight of 70 g / m ² was produced.

As is clear from Tables 1 and 2, the present invention includes a specific amount of kaolin, a wet paper strength agent, and a rosin sizing agent as fillers in the paper base material, and the aspect ratio of the tensile strength and the Steecht method sizing degree are controlled. It has been demonstrated that the paper backing paper can improve peelability, wet tensile strength, underwater dimensional stability, curl and peelability.

The backing paper for wallpaper of the present invention is excellent in peelability when peeling the wallpaper from the wall surface, wet tensile strength of the backing paper, dimensional change rate in water, curl, and phase peelability even though expensive materials are not used. This paper is very useful industrially.

Claims (4)

A backing paper comprising a paper base material containing pulp, wherein the pulp has a wet paper strength agent of 0.5 mass% to 3.0 mass%, a rosin sizing agent of 0.05 mass% to 0.3 mass%, kaolin 5% by mass to 25% by mass and a yield improver 0.001% by mass to 0.035% by mass, and a tensile strength aspect ratio measured according to JIS P 8113: 2006 is 1.0. Backing paper for wallpaper, characterized in that the Steecht sizing degree measured according to JIS P 8122: 2004 is 1 to 20 seconds. The backing paper for wallpaper according to claim 1, wherein the Canadian standard freeness (CSF) measured according to JIS P 8121-2012 of the pulp is 400 ml to 600 ml. JAPAN TAPPI paper pulp test method no. 27. The backing paper for wallpaper according to claim 1 or 2, wherein the underwater elongation measured according to 27: 2000 is 2.0% or less. Wallpaper backing paper according to claim 1, wherein the basis weight of the paper substrate is 60 to 100 / m ^2.