JP6528440B2 - Background paper for wallpaper - Google Patents

Description

  The present invention relates to a backing paper for wallpaper.

  Wallpaper or foam wallpaper such as vinyl wallpaper, paper wallpaper, olefin wallpaper etc. is mainly composed of a two-layer structure of an upper layer which gives design and a backing paper which supports the upper layer and gives workability. At the time of construction, these wallpapers are pasted to the wall by starch or water-based glue such as vinyl acetate, but the water in the glue is absorbed by the backing paper in this pasting process, and the foam wallpaper becomes soft, backing paper May extend due to increased water content. And there existed a problem of generation | occurrence | production of a curl becoming large, the sticking operation | work of the foam wallpaper to the wall surface becoming difficult, and making of the wallpaper of the wallpaper after sticking being easy to occur. Furthermore, when the glue is dried, the backing paper shrinks, and there is a problem (open space) that a gap is generated at the joint between adjacently pasted wallpapers when the attachment with good construction productivity is performed (opened). There was a drawback such as impairing the design.

  Therefore, as the backing paper for foam wallpaper which is hardly curled even when pasted and whose dimensional stability is also improved, the backing paper made by the drying part of the paper making process being dried by a so-called Yankee dryer is used. (See Patent Document 1).

  In addition, there has been proposed a backing paper which is less fluffing of backing paper, is excellent in printability, and is excellent in peelability when peeling a wallpaper from a wall surface (see Patent Document 2). However, in these inventions, in addition to the peelability when peeling the wallpaper from the wall surface, the technology to simultaneously satisfy the wet tensile strength, the dimensional stability in water, and the curl is not considered, and the above characteristics are insufficient. Met.

  In addition, it is difficult to curl even when glue is applied at the time of construction, and there is no opening after sticking, and it is easy to peel off at the time of pasting, and the backing for wallpaper for which the backing paper layer remaining on the wall after peeling is uniform Paper has been proposed (see Patent Document 3). Furthermore, a backing paper for wallpaper has been proposed in which occurrence of fuzzing is small at the time of coating of a vinyl chloride paste or the like or in a subsequent drying step and no opening occurs after the wallpaper construction (see Patent Document 4). However, in these inventions, when the melting point of the core-sheath fiber is low, there is a concern about dryer fouling in the paper making process or the drying process. In addition, polyethylene fibers have a high calorie content after natural fibers and polyester fibers, and the calorie content after wallpaper processing is increased, which is insufficient for imparting flame resistance.

JP 2005-82894 A JP, 2009-242982, A Japanese Patent Application Publication No. 2007-077526 JP, 2010-229604, A

  The present invention relates to a backing paper for wallpaper, which is free from stains on the dryer in a papermaking process or a drying process, provides dimensional stability at the time of wallpaper construction, and provides a backing paper for wallpaper having excellent peelability when peeling wallpaper from a wall surface. The main purpose is to

The inventors of the present invention conducted intensive studies in view of the above prior art, and as a result, contained synthetic fibers having a core-sheath structure, and adjusted the paper interlayer strength after heating at 110 ° C. for 10 minutes to 55 N / m or less. The background paper for wallpaper has solved the above problems. That is, the present invention relates to the following backing paper for wallpaper.

Item 1: A backing paper for wallpaper comprising a fiber comprising at least a pulp fiber and a synthetic fiber having a core-sheath structure, and a paper base containing a filler, wherein the filler is 2% by mass in the total solid amount of the paper base The melting point of the core of the synthetic fiber having the core-sheath structure is 200 ° C. or higher, the melting point of the sheath is 115 ° C. or higher, and the paper interlayer strength after heating at 110 ° C. for 10 minutes is Backing paper for wallpaper characterized by being 55 N / m or less.

  Item 2: The backing paper for wallpaper according to Item 1, which contains the synthetic fiber having the core-sheath structure at a ratio of 5 to 30% by mass in the solid amount of all the fibers.

  Item 3: The backing paper for wallpaper according to Item 1 or 2, wherein the filler is one selected from the group consisting of kaolin, calcium carbonate, aluminum hydroxide, titanium dioxide, amorphous silica and calcined clay.

  Item 4: The backing paper for wallpaper according to any one of Items 1 to 3, wherein the melting point of the sheath part is 140 ° C. or more.

  Item 5: The backing paper for wallpaper according to any one of Items 1 to 4, wherein the synthetic fiber having a core-sheath structure is a polyester fiber having a core-sheath structure.

  Item 6: The wallpaper backing according to any one of items 1 to 5, wherein the melting point of the sheath is lower than the melting point of the core, and the difference between the melting points of the sheath and the core is 40 to 120 ° C. paper.

  Item 7: A backing paper for wallpaper according to any one of Items 1 to 6, further comprising a coating layer containing a water-soluble resin and / or a water-dispersible resin on at least one surface of the paper substrate.

  The backing paper for wallpaper of the present invention does not have a dryer stain in a paper making process or a drying process, is excellent in dimensional stability at the time of wallpaper construction, and is excellent in peelability when peeling wallpaper from a wall surface. In addition, fuzzing can be significantly suppressed.

  The wallpaper backing paper of the present invention comprises a fiber comprising at least a pulp fiber and a synthetic fiber having a core-sheath structure, and a paper base containing a filler. Such a paper substrate can be obtained, for example, as a web-like paper substrate by forming a paper layer by a paper making process using these raw material slurries and drying in a paper making process or a drying process. The paper making conditions are not particularly limited. As the paper machine, known ones such as a Fourdrinier paper machine, a twin wire paper machine, a cylinder paper machine and the like can be appropriately used. The drying conditions are not particularly limited. For example, a cylinder drier, a Yankee drier, an infrared drier, a hot air drier or the like can be used singly or in combination of two or more. The paper substrate is placed at a high temperature of about 100 to 110 ° C. by using, for example, superheated steam in a paper making process or a drying process. At this time, the synthetic fiber having a core-sheath structure is slightly softened even at a high temperature and lower than the melting point, causing fusion and staining the dryer, and this stain is transferred to the paper substrate, etc. As a result, there is a risk that paper dust and uneven defects may deteriorate the quality.

  The synthetic fiber having a core-sheath structure is not particularly limited as long as the sheath part is a heat-fusion component, and the core part may be concentric or eccentric. From the viewpoints of adhesion to the main fiber, blocking resistance in the paper making process, dispersibility, etc., it is more preferable to dispose synthetic fibers of high melting point in the core and synthetic fibers of low melting point in the sheath. In the synthetic fiber, various stabilizers, ultraviolet light absorbers, thickening / branching agents, matting agents, coloring agents and other various improving agents may be blended as needed.

  The wallpaper backing paper comprising this paper base material can be provided with a decorative layer on at least one side thereof to form a wallpaper. As wallpaper, for example, vinyl wallpaper provided with a vinyl chloride resin layer as a decorative layer, olefin wallpaper provided with an olefin resin layer, woven wallpaper provided with a woven layer, paper wallpaper provided with a paper layer, inorganic material provided with an inorganic layer Wallpaper products such as wallpaper can be mentioned. In any case, the cosmetic layer can be printed, foamed or embossed as required. At the time of formation of this wallpaper, heat treatment is usually performed at a high temperature of about 200.degree. At this time, the fibers of the paper base are fused to each other to increase the strength between paper layers, and a sufficient strength as a wallpaper is developed. However, excessive increase in the interlayer strength of the paper may impair the peelability. Peel aptitude is a property contrary to the paper interlayer strength. For example, when the wallpaper is peeled off at the time of reworking such as a reform, a certain cohesive failure is caused in the thickness direction of the paper layer forming the backing paper for wallpaper, and the paper interlayer Is required to be uniformly destroyed and not to make the wall surface uneven.

In the present invention, attention is paid to the fact that synthetic fibers having a core-sheath structure cause fusion even below the melting point, and the interlayer strength of paper for backing paper for wallpaper after heating at 110 ° C. for 10 minutes is 55 N / m or less, preferably 50 N It adjusts to / m or less. Thereby, there is no risk of staining the dryer in the papermaking process or the drying process, and it is possible to potentially give the paper interlayer strength developed at the time of wallpaper production. After heating at a temperature lower than 100 ° C., it is difficult to obtain a correlation with the paper interlayer strength developed at the time of wallpaper production. In addition, the paper interlayer strength in the present invention is described in JAPAN TAPPI No. According to 19-2, it measures at an angle of 180 degrees.

  In the present invention, in order to adjust the inter-layer strength of the backing paper for wallpaper after heating to 55 N / m or less, the melting point of the sheath portion of the synthetic fiber having a core-sheath structure is 115 ° C. or higher, or It can adjust by containing a filler in the ratio of 2 mass% or more in the total solid amount of a paper base material. 140 degreeC or more is preferable, as for melting | fusing point of a sheath part, 150 degreeC or more is more preferable, and 180 degreeC or more is still more preferable. The lower limit of the paper interlayer strength is not particularly limited, and may be adjusted according to the melting point of the sheath and the upper limit of the content ratio of the filler, preferably 10 N / m or more, more preferably 15 N / m or more, further preferably 20 N / m. m or more.

  If the melting point of the sheath portion of the synthetic fiber having a core-sheath structure is less than 115 ° C., dryer stains are significantly generated in the papermaking process or the drying process. Furthermore, there is a possibility that fusion occurs to excessively increase the strength between paper layers and to deteriorate the handling property and the peelability at the time of wallpaper production. On the other hand, if the melting point of the core portion is lower than 200 ° C., softening and melting may occur at the time of wallpaper production, and desired dimensional stability can not be obtained. The upper limit of the melting point is not particularly limited, and can be appropriately selected from the viewpoint of enhancing the type and productivity of industrially available synthetic fibers. The temperature at the sheath portion is preferably 200 ° C. or less, more preferably 180 ° C. or less. On the other hand, in the core portion, the temperature is preferably 300 ° C. or less.

  As a synthetic fiber having a core-sheath structure, it is preferable that the melting point of the sheath be lower than the melting point of the core from the viewpoint of improving the adhesion to the pulp fiber and effectively suppressing the drier stain. About 40-120 degreeC is preferable, and, as for the difference of melting | fusing point, about 80-110 degreeC is more preferable. The adhesion property of the fiber can be improved by having a core-sheath type structure in which a polymer having a melting point lower by 40 ° C. or more than the polymer forming the core part is disposed on the surface as a heat fusion component. On the other hand, by setting the difference in melting point to 120 ° C. or less, it is possible to effectively suppress dryer stains.

  The content ratio of the synthetic fiber having a core-sheath type structure is not particularly limited, and is preferably about 5 to 30% by mass in the solid amount of all the fibers. 7-25 mass% is preferable, and 8-20 mass% is more preferable. By setting the content to 5% by mass or more, the dimensional stability in water can be improved. On the other hand, tensile strength can be improved by setting it as 30 mass% or less.

  In the present invention, the synthetic fiber having a core-sheath structure is preferably a polyester fiber having a core-sheath structure. Such polyester fibers have very low water absorbency compared to pulp and are less likely to swell in the presence of water. It is believed that the presence of such polyester fibers in the paper layer reduces the swelling inside the paper layer and, as a result, improves the dimensional stability of the paper in water. Further, in the present invention, by having a core-sheath structure, it is melted by heat in the drying step, and light adhesion is developed, so that it adheres to pulp fibers in the papermaking step or synthetic fibers It is believed that a large number of water-insoluble bonding points are formed by bonding, so that a wallpaper backing paper having excellent dimensional stability in water can be obtained.

  Although it does not specifically limit as a form of the polyester fiber which has a core-sheath structure, It is preferable that polyester and a heat-fusion component are core-sheath type. In this core-sheath type polyester fiber, polyester is the core, and the heat-fusion component of the low melting point polyester is the sheath.

  The polyester fiber in the present invention is a fiber composed of a polyester homopolymer or copolymer. Specific examples of such polyesters include polyesters such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, stereocomplex polylactic acid, and copolyesters obtained by copolymerizing the third component. Among these, polyethylene terephthalate is preferable from the viewpoint of industrial availability and high dimensional stability and adhesion. The material may also be polyester recycled by material recycling or chemical recycling, or polyethylene terephthalate formed using the biomass described in JP 2009-091694A, that is, a monomer component obtained using a biological material as a raw material. Furthermore, the polyester obtained using the catalyst containing a specific phosphorus compound and a titanium compound which are described in Unexamined-Japanese-Patent 2004-270097 and Unexamined-Japanese-Patent 2004-211268 may be sufficient. In the polymer, as necessary, within the range not impairing the object of the present invention, a micropore forming agent, a cationic dye dyeable agent, a coloring inhibitor, a heat stabilizer, a brightening agent, a matting agent and a coloring agent A hygroscopic agent and inorganic fine particles may be contained alone or in combination of two or more.

  Here, as polyester-based elastomers disposed as a heat fusion component, polyether ester copolymers obtained by copolymerizing thermoplastic polyester as hard segment and poly (alkylene oxide) glycol as soft segment, more specifically Aliphatic acid such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid Aliphatic dicarboxylic acids such as dicarboxylic acids, succinic acids, oxalic acids, adipic acids, sebacic acids, dodecanedioic acids, dimer acids, etc., or at least one dicarboxylic acid selected from ester forming derivatives thereof, etc. 4-butanediol, ethylene glycol, trimethylene glycol Aliphatic diols such as tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol or alicyclic rings such as 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanemethanol At least one diol component selected from formula diols or ester-forming derivatives thereof and the like, and polyethylene glycol having an average molecular weight of about 400 to about 5,000, poly (1,2- and 1,3-polypropylene oxides ) Poly (alkylene oxide) glycols such as glycol, poly (tetramethylene oxide) glycol, copolymer of ethylene oxide and propylene oxide, copolymer of ethylene oxide and tetrahydrofuran Out it can be mentioned terpolymer composed of at least one.

  In particular, from the viewpoint of adhesion, temperature characteristics and strength, block copolymerized polyetheresters are preferred, in which polybutylene terephthalate is a hard component and polyoxybutylene glycol is a soft segment. In this case, the polyester portion constituting the hard segment is polybutylene terephthalate in which the main acid component is terephthalic acid and the main diol component is the butylene glycol component. Of course, a part of this acid component (usually 30 mol% or less) may be substituted with another dicarboxylic acid component or an oxycarboxylic acid component, and a part of the glycol component (usually 30 mol% or less) May be substituted with a dioxy component other than the butylene glycol component. Also, the polyether portion constituting the soft segment may be a polyether substituted with a dioxy component other than butylene glycol.

  Copolymerized polyester-based polymers include aliphatic dicarboxylic acids such as adipic acid and sebacic acid, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and naphthalenedicarboxylic acid, and / or fats such as hexahydroterephthalic acid and hexahydroisophthalic acid A co-polycarbonate containing a predetermined number of cyclic dicarboxylic acids and aliphatic or alicyclic diols such as diethylene glycol, polyethylene glycol, propylene glycol and paraxylene glycol, and optionally adding an oxyacid such as parahydroxybenzoic acid Polymerized ester etc. can be mentioned, for example, polyester etc. which add isophthalic acid and 1, 6- hexanediol in terephthalic acid and ethylene glycol are copolymerized.

  In addition, as long as the effects of the present invention are not impaired, synthetic fibers of polyolefin polymers such as low density polyethylene, high density polyethylene, polypropylene, and those obtained by modifying them can be contained.

  The fiber length of the synthetic fiber having a core-sheath structure is preferably 3 to 7 mm. By setting the fiber length to 3 mm or more, dimensional stability can be improved. On the other hand, by setting the size to 7 mm or less, it is possible to reduce the generation amount of fuzzing, and at the time of preparation process such as fiber disaggregation or dispersion, synthetic fibers or synthetic fibers in piping, pulp storage tank, paper machine stock inlet, dewatering wire, etc. It is possible to improve papermaking suitability by reducing the possibility that the fibers and wood pulp fibers are intertwined to form flocs, and the possibility of deterioration of formation and breakage of paper easily occurring. A more preferable range of fiber length is 4 to 6 mm. The fiber length in the present invention is a value obtained by measuring a weight-weighted average fiber length using FIBER LAB manufactured by METSO, which is an optical fiber length measuring device.

  The fineness of the synthetic fiber having a core-sheath structure is preferably 0.1 to 4.0 dtex. By setting the fineness of the polyester fiber to 0.1 dtex or more, it is possible to enhance the paper strength of the backing paper for wallpaper and to reduce the possibility of the sheet breaking easily. On the other hand, by setting the density to 4.0 dtex or less, the generation amount of fuzz can be reduced. The range of the fineness is more preferably 0.5 to 3.3 dtex, and still more preferably 1.0 to 2.5 dtex. In addition, 1 dtex is the mass (number of grams) per 10000 m.

  Specific examples of pulp fibers that can be used for the paper base in the present invention include, for example, bleached softwood lumber kraft pulp (NBKP), hardwood lapped bleached kraft pulp (LBKP), ground pulp (GP), thermomechanical pulp (TMP) And natural pulp such as non-wood pulp such as bast pulp, linter pulp and hemp pulp, and wood-based pulp such as chemithermomechanical pulp (CTMP) and deinked pulp (DIP). These pulp fibers can be used singly or in combination of two or more. Among them, wood pulp is preferably used in terms of quality and cost.

  In addition, wet paper strengthening agents, sizing agents, fillers, retention aids, fixing agents, dry paper strengthening agents, dyes, pigments, etc. are internally added to the paper base of the backing paper for wallpaper insofar as the quality is not affected. It can be used as a medicine.

  In the present invention, it is preferable to contain the wet paper strengthening agent in a proportion of 0.5 to 3.0% by mass in the total solid amount of the paper base. The content ratio is more preferably 0.7 to 2.5% by mass, and further preferably 0.8 to 2.0% by mass. By setting the content ratio of the wet strength agent to 0.5% by mass or more, the reduction in dimensional stability in water and the curl can be effectively suppressed, and the workability at the time of sticking the wallpaper can be improved. On the other hand, if it exceeds 3.0% by mass, the effect on the dimensional stability in water becomes a ceiling, so by controlling it to 3.0% by mass or less, the cost is suppressed and the effect of improving the disaggregation property of the broke is also obtained. Be

  Specific examples of the wet strength agent include, for example, polyamide-epichlorohydrin, polyamine-epichlorohydrin, epoxy resin, melamine resin and the like. In particular, it is preferred to use polyamide-epichlorohydrin or polyamine-epichlorohydrin.

  In the present invention, a sizing agent can be used as needed. The sizing agent may be internal or external. As sizing agents to be used, rosin type sizing agents, rosin type emulsion sizing agents, α-carboxymethyl saturated fatty acids, alkyl ketene dimers, alkenyl succinic anhydrides, cationic polymer type sizing agents and the like can be mentioned. Among these, rosin type sizing agents are preferable. The content ratio is not particularly limited, but is preferably 0.5% by mass or less, and more preferably 0.4% by mass or less, based on the total solid amount of the paper substrate, from the viewpoint of reducing the possibility of soiling in the papermaking system. 0.3 mass% or less is still more preferable. A sulfuric acid band (aluminum sulfate) can be used as a fixing agent for this rosin-based sizing agent.

  In the present invention, for example, a polyacrylamide based compound, a polyethylene glycol based compound, a polyvinylamine based compound and the like can be contained as a retention aid. Among these, cationic polyacrylamide type compounds are particularly preferable. In the case where the filler is kaolin, the overall retention is likely to be reduced, so an appropriate retention agent may be selected appropriately to improve the productivity. The content of the retention aid is not particularly limited, but is preferably 0.001 to 0.035% by mass, more preferably 0.005 to 0.030% by mass, and still more preferably 0.008 to 0.020% by mass. .

  In the present invention, it is preferable to adjust the freeness (Canadian standard freeness) measured according to JIS P 8121-2012 of the pulp fiber to be used to 400 to 600 ml. The freeness of the pulp may be adjusted to the above range by beating the at least one kind of pulp described above. When two or more types of pulp are used, the pulps that have been separately beaten may be mixed to make the above-mentioned range, or the pre-mixed pulp may be beaten and adjusted to the above-mentioned range. By setting the freeness of the pulp to 400 ml or more, it is possible to effectively reduce the elongation when applying the wallpaper with an aqueous paste. In addition, shrinkage at the time of drying can also be reduced, and therefore, it is possible to further reduce the gap (gap) of the wallpaper pasted next to each other, which is preferable. On the other hand, by setting the amount to 600 ml or less, paper strength can be increased, wet strength can be improved, and fuzzing of the paper base can be suppressed.

  The paper base in the present invention contains a filler at a proportion of 2% by mass or more in the total solid amount of the paper base. The content ratio is preferably 3% by mass or more. On the other hand, 20 mass% or less is preferable, 18 mass% or less is more preferable, and 17 mass% or less is still more preferable. When the content ratio is less than 2% by mass, the opacity is insufficient, the paper interlayer strength is excessively increased, and the peelability at the time of peeling the wallpaper from the wall surface at the time of reworking becomes insufficient. On the other hand, if it exceeds 20% by mass, the tensile strength becomes insufficient.

  The filler contained in the paper base is not particularly limited, and kaolin, delaminated kaolin, ground calcium carbonate, light calcium carbonate, light calcium carbonate-silica composite, magnesium carbonate, barium carbonate, titanium dioxide, oxidized Inorganic fillers such as zinc, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, calcined clay, and organic fillers such as urea-formalin resin, styrene resin, and phenol resin are desired. You may use together in the range which does not inhibit an effect. Among them, at least one selected from kaolin, aluminum hydroxide, calcium carbonate, titanium dioxide, amorphous silica and calcined clay is preferable from the viewpoint of improving the peelability. In addition, kaolin, aluminum hydroxide, calcium carbonate, titanium dioxide and an amorphous material are adjusted from the viewpoint of suppressing a drop in paper stiffness at the time of paste application by adjusting so as not to excessively suction the paste for bonding to a wall. At least one selected from silica is preferred. In the present invention, by containing flat sheet kaolin as a filler for wallpaper backing paper, the interlayer strength of the wallpaper backing paper can be lowered with a small amount of addition, and when the wallpaper is peeled off, it is uniformly peeled off. Is preferable.

  The wallpaper backing paper of the present invention produced as described above preferably has a Canadian standard freeness (CSF) of 400 to 600 ml when redisintegrated. By setting the freeness of Canada at the time of re-disintegration to 400 ml or more, when applying and applying a water-based paste to a wallpaper product, the elongation can be effectively reduced and the shrinkage upon drying can be reduced. This makes it possible to further reduce the gaps (gaps) of the wallpaper pasted next to each other. On the other hand, by setting the amount to 600 ml or less, it is possible to increase the paper strength and to suppress the generation of fuzzing on the paper substrate. In addition, when the backing paper for wallpaper contains a filler, the freeness at the time of re-disintegration from the freeness of pulp alone tends to decrease. The Canadian standard freeness at the time of redisintegration may be the same as or different from the Canadian standard freeness of the pulp used alone.

  The tensile strength of the backing paper for wallpaper is preferably 1.50 kN / m or more, more preferably 2.00 kN / m or more. By setting the tensile strength to 1.50 kN / m or more, sufficient tensile strength can be obtained in handling at the time of production or processing during winding, and there is a risk that paper breakage may occur at the time of winding and productivity may be reduced. Absent.

  The wet tensile strength of the backing paper for wallpaper is preferably 0.30 kN / m or more, more preferably 0.35 kN / m or more. By setting the wet tensile strength to 0.30 kN / m or more, it is possible to enhance the strength after application of the paste, to suppress the occurrence of breakage or the like at the time of construction, and to improve the working efficiency. The wet tensile strength may be adjusted, for example, by adjusting the type and amount of wet strength agent.

  The underwater elongation of the backing paper for wallpaper is preferably 1.5% or less, more preferably 1.0% or less, from the viewpoint of improving the curling prevention and the opening prevention. In addition, the water elongation was measured using the JAPAN TAPPI Paper Pulp Test Method No. 27: measured according to 2000.

  In the present invention, it is preferable to provide a coating layer containing a water-soluble resin and / or a water-dispersible resin on at least one surface of the paper substrate. As a result, it is possible to significantly suppress the occurrence of fuzzing caused by dryer fouling in a paper making process or a drying process caused by a synthetic fiber having a core-sheath type structure.

  Examples of water-soluble resins include fully saponified or partially saponified polyvinyl alcohol, ethylene modified polyvinyl alcohol, acetoacetyl modified polyvinyl alcohol, diacetone modified polyvinyl alcohol, modified polyvinyl alcohol such as carboxy modified polyvinyl alcohol and silicon modified polyvinyl alcohol, starch and the like Derivatives, methoxycellulose, carboxymethylcellulose, hydroxypropyl methylcellulose, cellulose derivatives such as methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic acid amide-acrylic acid ester copolymer, acrylic acid amide-acrylic acid ester-methacrylic acid copolymer Polymer, styrene-maleic anhydride copolymer salt, styrene-acrylic acid copolymer salt, polyacek Ruamido, sodium alginate, gelatin, casein, and the like. As a salt, a sodium salt, a potassium salt, an ammonium salt, or a coexistence of these salts is also applicable.

  Examples of water dispersible resins include polyvinyl acetate, polyurethane, styrene-butadiene copolymer, styrene-acrylic copolymer, styrene-butadiene-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyacrylic acid, poly Homopolymers or copolymers of acrylic acid ester, vinyl chloride-vinyl acetate copolymer, polybutyl methacrylate, ethylene-vinyl acetate copolymer, silylated urethane, acrylic-silicon complex, acrylic-silicon-urethane complex, etc. Coalesced resin is mentioned. These may be used in the form of an emulsion or latex.

  The water-soluble resin and / or the water-dispersible resin can be used singly or in combination of two or more. Among these, the water-soluble resin is preferably one selected from the group consisting of polyvinyl alcohol and styrene-acrylic acid copolymer salt. Further, it is preferable that the water dispersible resin is a styrene-acrylic copolymer resin. This makes it possible to significantly suppress fuzzing by the synthetic fiber having a core-sheath type structure.

  In the present invention, the water-soluble resin is preferably ethylene-modified polyvinyl alcohol. This can effectively suppress fuzzing. Ethylene-modified polyvinyl alcohol is commercially available, for example, as "EXEVAL" series manufactured by Kuraray Co., Ltd., and can be easily obtained and used.

  The ethylene-modified polyvinyl alcohol which can be used in the present invention is a polyvinyl alcohol in which an ethylene group is introduced into the main chain of polyvinyl alcohol. The content of ethylene units (degree of ethylene modification) is expressed in mol% with respect to the whole monomer units (ethylene units + vinyl alcohol units) (however, vinyl alcohol units also include unsaponified vinyl acetate units) . The ethylene modification degree is not particularly limited, but is preferably 2 to 12 mol%, and more preferably 4 to 8 mol%.

  The average degree of polymerization of ethylene-modified polyvinyl alcohol (measured according to JIS K 6726-1994) in the present invention is preferably 800-1500. When the average degree of polymerization is 800 or more, the coatability is improved. On the other hand, by setting the average degree of polymerization to 1,500 or less, the solubility in water can be improved, and it can be prevented that the viscosity becomes too high and coating becomes difficult.

  80 mol% or more is preferable, as for the saponification degree of ethylene modified polyvinyl alcohol in this invention, 90 mol% or more is more preferable, and 95 mol% or more is still more preferable. By setting the degree of saponification to 80 mol% or more, the water solubility can be enhanced to improve the coatability.

  The coating layer in the present invention is coated or impregnated with a coating liquid containing a water-soluble resin and / or a water-dispersible resin on at least one surface of a paper substrate, and dried to thereby obtain a paper substrate. It is surface-treated. In the coating solution, if necessary, various known assistants such as surfactants such as polyoxyethylene (5 mol addition) polyoxypropylene (30 mol addition) block polymer, antifoaming agents, dyes and pigments are used. May be

  The method for applying or impregnating the coating liquid is not particularly limited, and a generally known coating device can be used, and for example, a bar coater, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a curtain coater, a slot A die coater, a gravure coater, a chamfer coater, a brush coater, a slide bead coater, a size press coater of a two roll or metering blade system, a bill blade coater, a short dwell coater, a gate roll coater, a nip coater with a calender, etc. may be mentioned. Among these, in order to enhance production efficiency, it is preferable to use a film transfer type coater such as a gate roll coater or a rod metering size press coater.

The coating amount of the coating layer is not particularly limited, and is preferably in the range of 0.5 to 4.0 g / m ^{2 in} terms of the coating amount after drying per one side of the paper substrate, and 1.0 to 3.0 g. More preferably, it is in the range of / m ² . By setting the coating amount to 0.5 g / m ² or more, the effect of suppressing fuzz can be enhanced. On the other hand, by setting the amount to 4.0 g / m ² or less, equipment contamination in the paper making process or the drying process can be reduced. In the present invention, the coating layer is provided on at least one surface of the paper substrate, but may be provided on the other surface and the coating layer may be provided on both surfaces.

  The method for drying the coated layer is not particularly limited, and may be appropriately selected from those used in the paper making process or the drying process. Moreover, in the present invention, after forming a coating layer, smoothing processing can be performed as needed. The smoothing process is performed on-machine or off-machine using a smoothing apparatus such as a normal super calender, a gross calendar, a soft calendar or the like.

The basis weight of wallpaper backing sheet is preferably 40~150g / ^{m 2,} and more preferably 60 to 100 / ^{m 2.} By setting the basis weight to 40 g / m ² or more, the strength can be increased, and the possibility of sheet breakage during processing can be reduced. On the other hand, by setting it as 150 g / m < ² > or less, when it is processed into a wallpaper, it does not become too hard and construction becomes easy. In the present invention, from the viewpoint of adjusting the basis weight to a preferable range to exert the effects of the present invention without failure, it can be dried using a cylinder drier.

  The present invention will be described in more detail by way of examples, but the present invention is not limited by these. In addition, unless otherwise indicated, "part" and "%" show a "mass part" and "mass%", respectively.

Example 1
Hardwood bleached kraft pulp (Canadian standard freeness 450 ml) as a fiber, polyester fiber having a core-sheath structure with a fiber length of 5 mm and a fineness of 2.2 dtex (polyethylene terephthalate homopolymer having a melting point of 260 ° C., a sheath having a melting point) Polyester fiber having a core-sheath structure is 15 mass% of the total amount of fibers using a polyethylene terephthalate copolymer at 150 ° C. and kaolin (trade name: “UW-90”, manufactured by BASF) as a filler. The raw material slurry was prepared such that the% of kaolin was 5% by mass in the total solid amount of the paper base. The raw material slurry contains 0.5 parts by mass of a sulfuric acid band, and a rosin sizing agent (trade name: “size pine N 775”, solid content concentration 50%, Arakawa Chemical Co., Ltd.) based on 100 parts by mass of pulp raw material in terms of solid content. 0.1% by mass, and as a wet paper strength agent, polyamide epichlorohydrin resin (trade name: "ARAFIX 255", solid content concentration 25%, manufactured by Arakawa Chemical Industries, Ltd.) 1.0 Parts by weight were added. Furthermore, 0.01 parts by mass of cationic polyacrylamide (trade name: “Ke's Lock RP 401L”, manufactured by Kyowa Sangyo Co., Ltd.) was added as a retention aid. Using a mixture obtained by adding these, through a paper making process and a drying process using a Fourdrinier paper machine and a cylinder drier, a paper base material having a basis weight of 70 g / m ² is obtained, and a backing paper for wallpaper did.

Example 2
Hardwood bleached kraft pulp (Canadian standard freeness 450 ml) as a fiber, polyester fiber having a core-sheath structure with a fiber length of 5 mm and a fineness of 2.2 dtex (polyethylene terephthalate homopolymer having a melting point of 260 ° C., a sheath having a melting point) Using polyester terephthalate copolymer at 150 ° C and using kaolin as a filler (trade name: "UW-90", manufactured by BASF Corp.) The raw material slurry was prepared so that the percentage of kaolin was 9% by mass in the total solid amount of the paper base. The raw material slurry contains 0.5 parts by mass of a sulfuric acid band, and a rosin sizing agent (trade name: “size pine N 775”, solid content concentration 50%, Arakawa Chemical Co., Ltd.) based on 100 parts by mass of pulp raw material in terms of solid content. 0.1% by mass, and as a wet paper strength agent, polyamide-epichlorohydrin resin (trade name: "ARAFIX 255", solid content concentration 25%, manufactured by Arakawa Chemical Industries, Ltd.) 1.0 Parts by weight were added. Furthermore, 0.01 parts by mass of cationic polyacrylamide (trade name: “Ke's Lock RP 401L”, manufactured by Kyowa Sangyo Co., Ltd.) was added as a retention aid. Using a mixture obtained by adding these, a paper base of 70 g / m ^{2 in} basis weight was obtained through a paper making process and a drying process using a Fourdrinier paper machine and a cylinder drier. While obtaining this paper base, using a size press coater in the paper making process, using a 4% aqueous solution of ethylene-modified polyvinyl alcohol (trade name: "EXEVAL HR 3010, manufactured by Kuraray Co., Ltd.) as a coating liquid, The coating layer was applied so that the coating amount after drying was 1.0 g / m ² per one side, and a backing paper for wallpaper having a basis weight of 72 g / m ² was obtained.

Example 3
In Example 2, except for changing the melting point of the sheath of polyester fiber to 150 ° C. to 180 ° C., and changing the content ratio of polyester fiber to 25 mass% to 15 mass%, for wallpaper in the same manner as in Example 2. I got a backing paper.

Example 4
In Example 2, the fiber length of the polyester fiber is changed to 5 mm to 3 mm, the melting point of the sheath is changed to 150 ° C. to 180 ° C., and the content ratio is changed to 25 mass% to 20 mass%, and the kaolin content ratio Was changed to 9% by mass to 8% by mass, and in the same manner as in Example 2, a backing paper for wallpaper was obtained.

Example 5
In Example 2, the fiber length of the polyester fiber is changed to 5 mm to 7 mm, the sheath melting point is changed to 150 ° C. to 180 ° C., and the content ratio is changed to 25 mass% to 8 mass%, and the kaolin content ratio The backing paper for wallpaper was obtained in the same manner as in Example 2 except that 17 mass% was substituted for 9 mass%.

Example 6
A backing paper for wallpaper was obtained in the same manner as in Example 5 except that the basis weight of the paper base was changed to 50 g / m ² in Example 5. The basis weight of the backing paper for wallpaper was 52 g / m ² .

Example 7
In Example 2, the melting point of the sheath of polyester fiber is changed to 150 ° C. to 180 ° C., the content ratio of polyester fiber is changed to 25 mass% to 20 mass%, and the content ratio of kaolin is substituted to 9 mass%. A backing paper for wallpaper was obtained in the same manner as in Example 2 except that it was 3% by mass.

Comparative Example 1
A backing paper for wallpaper was obtained in the same manner as in Example 2 except that the melting point of the sheath of polyester fiber was changed to 150 ° C. to 130 ° C. in Example 2.

Comparative example 2
In Example 2, the melting point of the sheath of polyester fiber is changed to 150 ° C. to 180 ° C., the content ratio is changed to 25 mass% to 15 mass%, and the content ratio of kaolin is further changed to 9 mass% to 1 mass% A backing paper for wallpaper was obtained in the same manner as in Example 2 except for the above.

Comparative example 3
In Example 2, the melting point of the sheath of polyester fiber is changed to 150 ° C. to 180 ° C., the content ratio is changed to 25 mass% to 15 mass%, and the content ratio of kaolin is changed to 9 mass% to 25 mass% A backing paper for wallpaper was obtained in the same manner as in Example 2 except for the above.

Comparative example 4
In Example 2, the melting point of the sheath of the polyester fiber is changed to 150 ° C. to 180 ° C., the content ratio is changed to 25 mass% to 40 mass%, and the kaolin content ratio is changed to 9 mass% to 20 mass% A backing paper for wallpaper was obtained in the same manner as in Example 2 except for the above.

Comparative example 5
A backing paper for wallpaper was obtained in the same manner as in Example 2 except that polyester fiber was not used and the content of kaolin was changed to 9% by mass to 15% by mass.

  The following evaluation was performed about the paper backing for wallpaper obtained in this way, and each used fiber. The results are as shown in Table 1.

(Paper interlayer strength)
After cutting the backing paper for wallpaper into a width direction 25 mm × flow direction 250 mm as a sample and heating at 110 ° C. for 10 minutes, JAPAN TAPPI No. The interlaminar strength of the backing paper for wallpaper was measured at an angle of 180 degrees according to 19-2, and displayed in N / m units, and evaluated according to the following criteria.
○: 55 N / m or less, and there is no practical problem with peel aptitude.
X: larger than 55 N / m, peel aptitude is a problem in practical use.

(Tensile strength)
After cutting the backing paper for wallpaper in width direction 15 mm × flow direction 250 mm as a sample and heating it at 110 ° C for 10 minutes, the paper backing material for wallpaper is set to 180 mm according to JIS P 8113: 2006. The tensile strength was measured, expressed in kN / m, and evaluated according to the following criteria.
◎: 2.00 kN / m or more, no problem.
○: 1.50 kN / m or more and less than 2.00 kN / m, there is no problem in practical use.
X: less than 1.50 kN / m, which is a problem in practical use.

(Underwater elongation)
With regard to the backing paper for wallpaper, as an index of dimensional stability in the width direction, the JAPAN TAPPI Paper and Pulp Test Method No. 1 is used. The elongation in water was measured according to 27: 2000 and evaluated according to the following criteria.
○: 1.5% or less, there is no problem in practical use.
X: larger than 1.5%, which is a problem in practical use.

(Dryer dirt)
The dryer stain in the paper making process or the drying process was visually observed and evaluated according to the following criteria.
○: There is no transfer of fibers or resin to the dryer.
X: Transfer of fibers, resin, etc. to the dryer.

(Peel aptitude)
A cross tape (made by Oji Tac) was attached to one side of the backing paper for wallpaper to make a strip-like sample having a width of 11 cm and a flow of 5 cm. On the backing paper side of this sample, using a paste coating machine for wallpaper, a coating paste for wallpaper (Yayoi Kagaku Kogyo Co., Ltd., trade name: “ruemailed”) was applied at a coating amount of 120 g / m ² . The paste-coated surface was bonded to a gypsum board using a roller to obtain a sample for evaluation of peelability.

After holding the above-mentioned sample for evaluation of peelability for 24 hours under the condition of 23 ° C. and 50% RH, the sample for evaluation of peelability is peeled off from the gypsum board, and the gypsum board surface (wall surface) is visually observed. It evaluated by.
○: The backing paper for wallpaper is uniformly peeled between the paper layers, and no unevenness is observed on the wall surface.
X: The backing paper for wallpaper peeled off unevenly (occurrence of tear etc.), and unevenness was generated on the wall surface.

(Fiber length)
For polyester fibers having a core-sheath type structure, the weight-weighted average fiber length was measured using FIBER LAB manufactured by METSO, which is an optical fiber length measuring device.

(Fineness)
The denier of a polyester fiber having a core-sheath structure was measured using a motorcycle Blo-type denier measurement device Denior Computer DC-11 (manufactured by Search Control Electric Co., Ltd.).

  The backing paper for wallpaper of the present invention does not have a dryer stain in the paper making process or the drying process, has excellent dimensional stability at the time of wallpaper construction, peelability when peeling wallpaper from the wall, tensile strength of backing paper, underwater dimension It is a highly stable wallpaper backing paper, and is extremely useful industrially.

Claims (5)

A backing paper for wallpaper comprising a fiber comprising at least a pulp fiber and a synthetic fiber having a core-sheath structure, and a paper base containing a filler, wherein the filler is 3 % by mass to 18% of the total solid amount of the paper base %, And the melting point of the core of the synthetic fiber having a core-sheath structure is 200 ° C. or higher, and the melting point of the sheath is 150 ° C. to 180 ° C. after heating at 110 ° C. for 10 minutes paper interlayer strength Ri der following 20 N / m or more 55N / m, wallpaper backing paper, wherein the synthetic fiber having a core-sheath structure is a polyester fiber having a core-sheath structure.   The wallpaper backing paper according to claim 1, wherein the synthetic fiber having the core-sheath structure is contained in a ratio of 5 to 30% by mass in the solid amount of all the fibers.   The wallpaper backing paper according to claim 1 or 2, wherein the filler is one selected from the group consisting of kaolin, calcium carbonate, aluminum hydroxide, titanium dioxide, amorphous silica and calcined clay. The wallpaper backing paper according to any one of claims 1 to 3 , wherein the melting point of the sheath is lower than the melting point of the core, and the difference between the melting points of the sheath and the core is 40 to 120 ° C. The wallpaper backing paper according to any one of claims 1 to 4 , further comprising a coating layer containing a water-soluble resin and / or a water-dispersible resin on at least one surface of the paper substrate.