JP2011202325A - Backing paper for wallpaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide backing paper for wallpaper, causing no such a case that: in undergoing embossing, part of a thermoplastic synthetic fibers is fused and deposited as foreign matter (so-called fiber-seized phenomenon) to the back roll.SOLUTION: The backing paper for wallpaper includes ground paper that is obtained by undergoing a papermaking of slurry including: wood pulp; thermoplastic synthetic fibers; and a wax of a melting point of 50°C or higher and lower than 110°C. In the backing paper, it is preferable that 0.005 mass% or greater and less than 0.2 mass% of the wax is included, and the wax is paraffin-based or polyethylene-based one.

Description

  The present invention relates to a backing paper for wallpaper used for vinyl chloride wallpaper and the like.

  The wallpaper is used by sticking to a wall for a long time for indoor interior in a general house, a hotel, a hospital or the like. The wallpaper includes vinyl chloride wallpaper (hereinafter referred to as vinyl wallpaper), olefin wallpaper, fabric wallpaper, paper wallpaper, inorganic wallpaper, etc. These wallpapers include vinyl chloride resin layer, olefin resin layer, fabric layer, paper layer. And a decorative layer such as an inorganic layer and a backing paper for holding the decorative layer.

  These wallpapers are glued to the wall with starch or vinyl acetate resin water-based glue during construction, but the backing paper absorbs moisture in the glue during the gluing process, so the wallpaper becomes soft or the backing paper May increase due to increased moisture. For these reasons, the wallpaper is curled, making it difficult to apply to the wall, and causing problems such as the tendency of wrinkling after application. Furthermore, since the backing paper contracts when the glue dries, there is a problem in that a gap (opening) is generated at the joint portion between the adjacently bonded wallpapers, and the design properties after construction are impaired.

  For improving the dimensional stability of backing paper, backing paper blended with inorganic fibers such as glass fibers that are less stretched by moisture (Patent Documents 1, 2, and 3), backing blended with thermoplastic synthetic fibers such as polyolefin and polyester Paper (Patent Documents 4 and 5) is disclosed.

JP-A-4-21496 JP-A-8-1000039 JP-A-8-325997 JP-A-5-59699 Japanese Patent Laid-Open No. 2007-077526

However, since inorganic fibers such as glass fibers do not have self-adhesive properties, the fibers tend to fall off the sheet, resulting in poor workability, and fiber fluffing occurs during papermaking, wallpaper processing, and wallpaper construction. In addition, since the glass fiber is rigid, when it comes into contact with the skin, a tingling irritation occurs, which causes discomfort to humans. Therefore, backing paper containing inorganic fibers has not been widely used.
In addition, when thermoplastic synthetic fiber is blended, the thermoplastic fiber is melted by heating in the process of embossing the vinyl chloride layer, which is a decorative layer. For example, one thermoplastic synthetic fiber is placed on an embossed back roll (rubber roll). There was a problem of so-called fiber removal, in which the part was fused and adhered as foreign matter.
Accordingly, an object of the present invention is to provide a wallpaper backing paper in which a part of thermoplastic synthetic fiber is not fused and adhered as foreign matter (so-called fiber removal) to the back roll during embossing.

  As a result of intensive studies on the above-mentioned problems, the present inventors have found that fibers generated during embossing can be removed by internally adding a wax having a specific melting point to a wallpaper backing paper containing a thermoplastic synthetic fiber. It was found that (hereinafter referred to as back roll removal) can be improved, and the present invention was reached.

  That is, the present invention is a backing paper for wallpaper comprising a base paper obtained by papermaking a slurry containing wood pulp, thermoplastic synthetic fibers, and a wax having a melting point of 50 ° C. or higher and lower than 110 ° C. In addition, it is preferable that the content rate in the backing paper of the said wax is the range of 0.005 mass% or more and less than 0.2 mass%. The wax is preferably a paraffin wax and a polyethylene wax.

  The wallpaper backing paper of the present invention can prevent foreign matters such as fibers from adhering to the back roll (rubber roll) used during embossing even though no expensive material is used. In addition, when the wax is blended, surface fibers do not rise at the time of vinyl paste coating, so that the occurrence of fuzz is reduced.

  The wallpaper backing paper of the present invention comprises a base paper on which a slurry containing at least wood pulp, thermoplastic synthetic fibers, and a wax having a melting point of 50 ° C. or higher and lower than 110 ° C. is made. This facilitates peeling after contacting the back roll in embossing, so it is possible to reduce fuzz and reduce paper dust adhering to the back roll, which can also improve operability. It becomes.

<Wax>
In the present invention, the wax is an organic substance that becomes solid at room temperature and becomes liquid when heated. Specifically, natural wax such as beeswax, spermaceti, wood wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene Examples thereof include synthetic waxes such as waxes, oil-based synthetic waxes (fatty acid esters, fatty acid amides, ketones / amines), hydrogenated oils, and the like. In the present invention, it is preferable to use paraffin-based or polyethylene-based wax because it can be obtained at a relatively low cost.

  In the present invention, among the waxes, a wax having a melting point of 50 ° C. or higher and lower than 110 ° C. is used. Usually, the surface temperature of the back roll at the time of embossing is about 110 ° C. Therefore, when the melting point of the wax is 110 ° C. or higher, the wax present in the paper is not melted by the heat of the back roll surface. The peelability of the paper becomes insufficient, and back roll removal cannot be reduced. On the other hand, when the melting point is less than 50 ° C., the wax melts and flows during storage in a warehouse or the like, and the quality of the backing paper changes, which is not preferable. In addition, the range of especially preferable melting | fusing point is 55 to 100 degreeC at the point that a back roll is taken and the suppression effect is large.

In the present invention, the wax is preferably contained in the backing paper in a range of 0.005% by mass to less than 0.2% by mass. When the content of the wax in the paper is less than 0.005% by mass, the back roll peelability at the time of embossing is insufficient, and the back roll cannot be removed. In addition, in order to manufacture stably, it is preferable that wax contains more than 0.01 mass%.
On the other hand, when the content of the wax in the paper is 0.2% by mass or more, the adhesion between the decorative layer and the base paper tends to be lowered. Furthermore, if the content of the wax is high, bubbles tend to be generated when the raw material slurry is extruded onto the wire during papermaking, and sheet defects due to the bubbles tend to occur. Further, when drying with a Yankee dryer, the paper peels off from the Yankee dryer during the drying process, and the drying efficiency deteriorates. The wax content in the paper is preferably 0.15% by mass or less.

  In the present invention, a wax is mixed and dispersed in a slurry of wood pulp and pulp containing thermoplastic synthetic fibers, which will be described later, and paper is made. For this reason, it is desirable that the wax is emulsified (emulsified), and in particular, a cationic emulsion is preferable. Due to the cationic nature, in the case of acidic papermaking, it is possible to stably and uniformly disperse in the pulp slurry and to be easily adsorbed on the anionic wood pulp surface, thereby improving the wax yield. In the case of neutral papermaking, it can be similarly adsorbed on the surface of anionic wood pulp, and the yield is high.

  On the other hand, when the wax emulsion is nonionic, the yield tends to be low and the effect tends to be small. In addition, when the wax emulsion is anionic, in the case of acidic papermaking, the distribution in the raw slurry is unstable and the wax particles agglomerate, resulting in a non-uniform distribution. There is a tendency. Furthermore, the agglomerated wax particles tend to adhere to the piping of the paper machine and cause dirt. However, in the case of neutral papermaking, it is possible to adsorb an anionic wax emulsion on the anionic wood pulp surface by adding a cationic chemical such as a sulfuric acid band to the pulp slurry.

<Pulp>
The base paper used for the wallpaper backing paper of the present invention is obtained by papermaking wood pulp and thermoplastic synthetic fiber, which will be described later. As wood pulp, various wood pulps such as bleached kraft pulp (NBKP) of conifers, bleached kraft pulp (LBKP) of hardwood, groundwood pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), etc. are used alone. Or it can mix and use by arbitrary compounding ratios. Although it is possible to use deinked pulp (DIP), it is preferable not to mix it because dimensional stability is deteriorated. Moreover, it is also possible to contain non-wood pulp (kenaf, bamboo, etc.) as long as the effects of the present invention are not impaired.

  The wood pulp used in the present invention is preferably adjusted to a Canadian standard freeness (CSF) of 450 ml to 550 ml. The CSF of the pulp may be adjusted to the above range by beating at least one kind of pulp described above. 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. If the pulp CSF is less than 450 ml, when the paper is constructed using aqueous glue, not only will the wallpaper stretch, but also the shrinkage during drying will increase, and the wallpaper (gap) between the walls pasted will be larger. Since it becomes large, it is not preferable. Furthermore, since the fiber-to-fiber bond is strengthened, the interlayer strength is increased, and the peelability when peeling the wallpaper from the wall surface is deteriorated. If the CSF of the pulp is larger than 550 ml, the paper strength becomes insufficient, so that paper breakage is likely to occur during coating of vinyl paste and the like, and fluffing is likely to occur on the base paper, which is not preferable.

<Thermoplastic synthetic fiber>
The thermoplastic synthetic fiber used in the present invention is a chemical fiber made from a synthetic resin obtained by polymerizing a low molecular weight organic material, and contains a thermoplastic synthetic resin. Specifically, polyolefin resin fibers such as polyethylene and polypropylene, polyester resin fibers such as polyethylene terephthalate, polyamide resin fibers such as nylon, acrylic resin fibers such as polyacrylonitrile, polyurethane resin fibers, and polyvinyl chloride. And halogen-containing resin fibers. In addition, it is also possible to use a synthetic fiber in which the above synthetic resin is a copolymer resin, or a composite fiber containing two or more different synthetic resins in one fiber having a core-sheath structure, a sea-island structure, or the like. it can. These synthetic fibers may be used alone or as a mixture of a plurality of types.

  The wallpaper backing paper of the present invention preferably contains 5% by mass or more and 25% by mass or less of thermoplastic synthetic fibers in the fiber constituting the base paper. By using a synthetic fiber that hardly undergoes stretching due to moisture, it is possible to prevent the wallpaper from curling due to water absorption and the opening after drying. If the synthetic fiber is less than 5% by mass, the dimensional stability is inferior, and openings are generated. Moreover, when the content rate of a thermoplastic synthetic fiber exceeds 25 mass%, there exists a tendency for the generation | occurrence | production amount of fuzz and a fiber removal to increase. More preferably, it is 15 mass% or less.

<Others>
In order to improve the opacity, the backing paper for wallpaper of the present invention preferably contains 1 to 30% by mass of filler. As said filler, at least 1 sort (s) selected suitably from the fillers used in a general papermaking can be used. Examples of such fillers include kaolin, calcined kaolin, delaminated kaolin, clay, calcined clay, delaminated clay, illite, heavy calcium carbonate, light calcium carbonate, light calcium carbonate-silica composite, magnesium carbonate, Inorganic fillers such as barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, urea-formalin resin, polystyrene resin, phenol resin, etc. Organic fillers, etc. are mentioned and mixed with the above-mentioned pulp slurry to make paper. In the present invention, among the above-mentioned fillers, it is preferable to use a baked clay that can suppress the occurrence of blisters (blowing between the backing paper and the vinyl chloride layer) during vinyl paste coating. .

  In the wallpaper backing paper of the present invention, a coating liquid containing a water-soluble polymer and / or a water-dispersible polymer (binder) is applied to at least the surface on the side where the decorative layer is provided in order to increase the surface strength. It is preferable to do. For example, in the case of vinyl wallpaper, a vinyl chloride paste is applied to the surface of the wallpaper backing paper, heated and gelled, and then subjected to a printing process so that the vinyl chloride layer becomes a decorative layer. When the surface strength of the backing paper for wallpaper is low, the fibers on the paper surface become fluffy when the decorative layer is applied, and the fluffed part becomes a protrusion on the wallpaper surface after gelation, which causes printing failure.

  Water-soluble polymers include various modified starches such as oxidized starch and enzyme-modified starch, polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, casein, and the like, and water-dispersible polymers include styrene / butadiene copolymer latex, methyl methacrylate Acrylate / butadiene copolymer latex, acrylic emulsion, vinyl acetate emulsion and the like can be used alone or in combination as appropriate.

  In particular, polyvinyl alcohol is particularly preferable because the effect of suppressing fuzz of fibers on the surface of the wallpaper backing paper is increased. Furthermore, the higher the degree of saponification of polyvinyl alcohol, the greater the fuzz suppression effect. For this reason, it is preferable to use polyvinyl alcohol having a saponification degree of 90 or more in the present invention. Moreover, when the polymerization degree of polyvinyl alcohol is low, the effect of suppressing fuzzing is small, and when it is high, the viscosity of the coating solution increases and the coating property tends to deteriorate. For this reason, it is preferable that the polymerization degree of polyvinyl alcohol is 1000-2000 in this invention.

  In the present invention, flame retardancy can be imparted to the backing paper for wallpaper. In order to impart flame retardancy, it is possible to apply or impregnate the above-mentioned coating solution containing a flame retardant, or to mix aluminum hydroxide, magnesium hydroxide or the like into the backing paper as a filler. preferable. As the flame retardant, guanidine sulfamate, guanidine sulfamate methylolated product, guanidine phosphate, ammonium sulfamate, ammonium polyphosphate and the like can be used alone or in combination.

  The lining agent for wallpaper of the present invention may be internally and / or externally added with a sizing agent in the same manner as ordinary paper. As the sizing agent, in the case of acidic papermaking, a rosin sizing agent, a rosin emulsion sizing agent, an α-carboxylmethyl saturated fatty acid, and the like can be used. In the case of neutral papermaking, neutral papermaking rosin sizing agents, alkyl ketene dimers, alkenyl succinic anhydrides, and cationic polymer sizing agents can be used. The addition amount of the sizing agent is not particularly limited, but it is preferable to use the sizing agent so that it has a Steecht sizing degree of 10 seconds or more. In addition, in the external addition using a size press or the like, it is possible to use a surface sizing agent such as rosin or synthetic resin.

  Further, in the backing paper for wallpaper of the present invention, a fixing agent, a dry paper strength agent, a wet paper strength agent, a sulfuric acid band, a yield improver, and a dye may be used as internal additives within a range that does not affect the quality. it can. Further, surface paper strength agents, dyes, pigments (clay, kaolin, calcium carbonate, titanium dioxide, silica, etc.), and the like can be used as external chemicals to be applied or impregnated using a size press or the like.

The basis weight of the backing paper for wallpaper of the present invention is preferably 40 g / m ² or more and 120 g / m ² or less. If the basis weight is less than 40 g / m ² , the strength is low and paper breakage is likely to occur during processing. On the other hand, if the basis weight exceeds 120 g / m ² , it becomes too hard when processed into wallpaper, resulting in a drawback that the construction becomes difficult.
The backing paper for wallpaper of the present invention can be appropriately produced by a known paper machine, and the paper making conditions are not particularly limited. As the paper machine, a long net paper machine, a twin wire paper machine, a circular net paper machine, or the like can be used. In the case of multiple layers, an inclined paper machine or the like can be used.

  In addition, the evaluation of taking back roll is done by heat-pressing the wallpaper backing paper and a specific rubber material for a certain period of time with a heat seal tester, and then peeling the wallpaper backing paper, and deposits such as fibers are generated on the rubber material. Evaluate whether it remains.

  The backing paper for wallpaper of the present invention becomes a wallpaper by providing a decorative layer on the upper layer. For example, wallpaper products such as vinyl wallpaper provided with a vinyl layer as a decorative layer, olefin wallpaper provided with an olefin layer, woven wallpaper provided with a fabric layer, paper wallpaper provided with a paper layer, inorganic wallpaper provided with an inorganic layer, etc. It is done. In any case, after providing a layer to be a decorative layer, printing is performed as necessary, or a foaming process or an embossing process is performed to obtain a decorative layer. The present invention can be suitably used as a backing paper for vinyl wallpaper, but can also be used as a backing paper for other wallpaper.

  EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. In addition, about the backing paper for vinyl wallpaper produced in the Example and the comparative example, the content rate of the paper in a paper and evaluation of the back roll taking were performed by the method shown below.

<Measurement of wax content in paper>
1. A base paper containing no wax is uniformly impregnated with a wax having a changed concentration and then dried to prepare a sample in which the content of the wax is changed. The content (%) of the wax in the paper is calculated by the following formula. In order to uniformly impregnate the base paper, the wax and base paper are put into a decompression container, and a decompression process is performed until no bubbles are generated from the base paper.

2. A GC-MS analysis is performed on the sample and the base paper before impregnation, and a relational expression between the content (%) of the wax in the paper and the total peak area is obtained.
3. GC-MS analysis is performed on the samples produced in the examples and comparative examples, and the content of wax contained in the backing paper in the paper is calculated from the relational expression 2.

<Evaluation of taking back roll>
The wallpaper backing paper was conditioned for 24 hours in an environment of 23 ° C. and 50 RH%, and then cut to 15 cm (MD direction) × 3 cm (CD direction). In sampling, sufficient care was taken not to rub the paper.
Using a heat seal tester, the upper / lower temperature was set to 175/130 ° C., and from the upper side, pressure-bonding was performed in the configuration of wallpaper backing paper (W surface) / nitrile rubber / aluminum foil. The pressure bonding time was 7 minutes, and the pressure was 2.5 kgf / cm ² . After 7 minutes, a sample was taken out immediately, the wallpaper backing paper was peeled 180 °, and the degree of adhesion of the fibers to the nitrile rubber was evaluated. If it is more than Δ, it can be used practically without problems.
A: No fiber remains at all.
○: Slightly remained but almost no problem.
Δ: Fiber remains.
X: A lot of fibers remain and are lumped in some places.

<Evaluation of fluff>
The wallpaper backing paper was conditioned for 24 hours in an environment of 23 ° C. and 50 RH%, and then cut to 70 cm (MD direction) × 30 cm (CD direction). In sampling, sufficient care was taken not to rub the paper. ^Two high quality papers with a basis weight of 150 g / m ² were laid on a glass plate and fixed with clips. Next, place a sample of backing paper for wallpaper so that the F surface, which is the vinyl chloride coating surface, is on top, and a vinyl chloride paste at a coating speed of 2 m / min with a knife coater so that the coating thickness is 150 μm. Was applied for 1 minute in a dryer at 145 ° C. to gel the vinyl chloride paste. The number of protrusions (defects) generated in an area of 30 cm in the CD direction and 60 cm in the MD direction at the center of the gelled vinyl chloride layer surface was measured. The measured values of four samples prepared in the same manner were summed to obtain the number of protrusions per sample (number per 0.72 m ² ). ○ If it is above, it can be used without any practical problems.
○: The number of measured protrusions is 5 or less. Δ: 5 to 10 ×: 11 or more

<Example 1>
In a pulp slurry containing 89 parts by mass of hardwood bleached kraft pulp (CSF: 500 ml), 11 parts by mass of thermoplastic resin fibers (core polyester fiber (melting point: 256 ° C.), sheath: polyethylene fiber (melting point: 125 ° C.) are contained in the pulp slurry. A sulfuric acid band was added so that the papermaking pH was 4.5.
0.15 mass% of alpha carboxymethyl saturated fatty acid salt (trade name: NSP-S, manufactured by Seiko PMC Co., Ltd.) was added as a sizing agent. Furthermore, 0.2% by mass of polyamide / epichlorohydrin resin (trade name: WS-547, manufactured by Seiko PMC Co., Ltd.) was added as a wet paper strength agent, and then an internal paper strength agent polyacrylamide resin (trade name: Police) TRON 117, manufactured by Arakawa Chemical Co., Ltd.) was changed to 0.3% by mass. As a filler, calcined clay was added so as to have an ash content of 7%. In addition, polyethylene wax (trade name: Meikax PEC-17; manufactured by Meisei Chemical Co., Ltd., melting point 100 ° C.) was added as an internal release agent so that the content in the paper was 0.01% by mass, and a wallpaper backing paper was produced. did. The basis weight at this time was 65 g / m ² .

<Example 2>
A backing paper for wallpaper was prepared in the same manner as in Example 1 except that polyethylene wax as an internal release agent was added so that the content in the paper was 0.05% by mass.

<Example 3>
A backing paper for wallpaper was prepared in the same manner as in Example 1 except that polyethylene wax as an internal release agent was added so that the content in the paper was 0.15% by mass, and the fiber length of the synthetic fiber was changed to 5 mm. Created.

<Example 4>
Instead of polyethylene wax, paraffin wax (trade name: Paragit ASZ-5, melting point 55 ° C., cationic, manufactured by Meisei Chemical Industry Co., Ltd.) is added so that the content in the paper is 0.05% by mass, and papermaking A wallpaper backing paper was produced in the same manner as in Example 1 except that.

<Comparative Example 1>
A wallpaper backing paper was produced in the same manner as in Example 1 except that polyethylene wax was not added.

<Comparative example 2>
Wallpaper backing paper was produced in the same manner as in Example 1 except that polyethylene wax was not added and the fiber length of the synthetic fiber was changed to 5 mm.

  Table 1 summarizes the results of evaluation of the backing paper for wallpaper obtained in Examples and Comparative Examples.

  In Examples 1 to 4 corresponding to the wallpaper backing paper of the present invention, the back roll was taken, and the wallpaper backing paper having no problem with fuzzing could be obtained. On the other hand, in Comparative Examples 1 and 2 in which the base paper did not contain the internal release agent, back roll removal at a problematic level occurred. In particular, in Comparative Example 5 containing a synthetic fiber having a fiber length of 5 mm, fuzzing was also inferior.

Claims (3)

  A backing paper for wallpaper comprising a base paper obtained by making a slurry containing wood pulp, thermoplastic synthetic fiber, and a wax having a melting point of 50 ° C or higher and lower than 110 ° C.   The backing paper for wallpaper according to claim 1, wherein the wax is contained in the backing paper for wallpaper in a range of 0.005% by mass or more and less than 0.2% by mass.   The backing paper for wallpaper according to claim 1 or 2, wherein the wax is a paraffin wax and a polyethylene wax.