JP2008132689A - Manufacturing method of gypsum board and moisture conditioning gypsum board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a gypsum board of good production efficiency capable of shortening a drying time period at the time of manufacture of the gypsum board even in the case of using raw paper for the gypsum board, which is obtained by applying a printing pattern to the surface of cardboard as the raw paper of the gypsum board and forming a clear layer which has thickness of a degree having surface physical properties such as abrasion resistance, tape peeling resistance, etc., on the printing pattern applied to the surface of the cardboard. <P>SOLUTION: A baked gypsum slurry is held between two raw sheets for the gypsum board to be molded into a predetermined shape and the molded one is cured and dried to manufacture the gypsum board. In this manufacturing method, at least one of the raw sheets for the gypsum board is constituted by laminating a printing pattern layer and the clear layer on the surface of the cardboard in this order and the clear layer is formed of a specific porous film forming aqueous dispersion type composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a gypsum board having a decorative finish and a humidity control gypsum board.

  A gypsum board is generally manufactured by sandwiching a gypsum slurry as a gypsum core material between two base papers for gypsum board, molding and curing the gypsum board into a plate shape, and then cutting to a predetermined size through a drying process. Gypsum board is widely used as a building material because it has excellent fire resistance, heat insulation, workability, and economy. In recent years, humidity control gypsum boards having humidity control properties have begun to be used in order to cope with dew condensation caused by airtightness in houses and the like.

  When these gypsum boards are used as interior finishing materials such as walls, ceilings or storage, gypsum board base paper with a printed pattern on the surface is used at the time of gypsum board production, and design characteristics are given to the gypsum board. . Further, the above base paper used for the plasterboard with this makeup has a clear layer formed of a resin composition on the surface of the printed pattern layer in order to impart surface properties necessary as an interior finishing material. Is provided.

  However, since the conventional clear layer is composed of a resin film having low moisture permeability and low air permeability, excess moisture in the gypsum slurry is dried and released into the atmosphere in the drying process during the production of the gypsum board. It was difficult to say that the production efficiency of the gypsum board provided with the clear layer was long because drying took a long time.

  In particular, when a printed pattern layer and a clear layer are provided on a humidity control gypsum board, there is a strong tendency for drying to take a long time for the reasons described below. Most of the humidity control gypsum board is, for example, a gypsum core material having a moisture control property and further a gas adsorption property by containing a moisture absorbing / releasing material in the gypsum core material, such as the gypsum board described in Patent Document 1. Is granted. This moisture-absorbing / releasing material absorbs a large amount of moisture before the drying process at the time of manufacture, and therefore requires a longer drying time than ordinary gypsum board, which improves the production efficiency of humidity control gypsum board. This was significantly worse, and this led to an increase in cost.

  Further, when the conventional resin composition is used for forming the clear layer of the humidity control gypsum board subjected to the makeup, the clear layer inhibits the humidity control property and gas adsorbability imparted to the gypsum core material. For this reason, there is a problem that the imparted performance is not sufficiently exhibited.

  In order to deal with these problems described above, a method is conceivable in which the thickness of the clear layer formed on the surface of the base paper for gypsum board is significantly reduced to improve the moisture permeability and air permeability of the clear layer. However, in this case, the surface properties of the resulting gypsum board, such as wear resistance and tape peel resistance, are insufficient, and the basic function as an interior finish material is impaired.

JP 2005-247635 A

  Accordingly, an object of the present invention is to form a clear layer having a thickness sufficient to have surface properties such as abrasion resistance and tape peeling resistance by applying a printed pattern on the surface of the paperboard as a base paper for gypsum board. An object of the present invention is to provide a method for producing a gypsum board with good production efficiency, which can shorten the drying time during the production of the gypsum board even when using the base paper for gypsum board. Another object of the present invention is to provide a humidity control gypsum board excellent in surface properties such as design properties, abrasion resistance and tape peel resistance, humidity control properties, and gas adsorption properties.

  The above problems are solved by the present invention described below. That is, the present invention is a gypsum board in which a gypsum slurry mainly composed of calcined gypsum serving as a gypsum core and water is sandwiched between two base papers for gypsum board, molded into a predetermined shape, cured, and dried. In this manufacturing method, at least one of the base paper for gypsum board is formed by laminating a printed pattern layer and a clear layer on the surface of the paper board in the order described, and the clear layer is dispersed in a porous film forming water. The porous film-forming water-dispersed composition is composed mainly of a film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm and water and colloidal silica. The film-forming aqueous emulsion is an emulsion obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer and acrylic silane or vinyl silane, and the colloidal silica is The synthetic resin particles have a particle size of 1/3 or less, and the amount of the colloidal silica is 0.5 to 30 times the mass that completely covers the synthetic resin particles. It is the manufacturing method of the gypsum board characterized.

  Further, in the method for producing a gypsum board of the present invention, the printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is A film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm and water and colloidal silica, and the film-forming aqueous emulsion comprises an α, β-ethylenically unsaturated monomer and An emulsion obtained by emulsion polymerization of acrylic silane or vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and the compounding amount of the colloidal silica is the synthetic resin. It is preferable to have a configuration that is 0.5 to 30 times the mass that completely covers the particles.

  Further, the present invention is a gypsum board in which a gypsum slurry mainly composed of calcined gypsum serving as a gypsum core and water is sandwiched between two base papers for gypsum board, molded into a predetermined shape, cured, and dried. In this manufacturing method, at least one of the base paper for gypsum board is formed by laminating a printed pattern layer and a clear layer on the surface of the paper board in the order described, and the clear layer is dispersed in a porous film forming water. The porous film-forming water-dispersed composition contains a resin emulsion having a solid content of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass. It is the manufacturing method of the gypsum board characterized by having the structure to do.

  In the method for producing a gypsum board of the present invention, the printed pattern layer is formed of a printing ink using a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is a solid It is preferable to have a configuration containing a resin emulsion having a content of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass.

  In the method for producing a gypsum board according to the present invention, the clear layer preferably has an average film thickness of 2 to 50 μm.

  The present invention also provides a humidity control gypsum board in which a gypsum core material containing a moisture absorbing / releasing material is sandwiched between two base papers for gypsum board, wherein at least one of the base papers for gypsum board is paperboard. A printed pattern layer and a clear layer are laminated in the order described here, and the clear layer is formed of a porous film-forming water-dispersed composition, and the porous film-forming water-dispersed type The composition mainly comprises a film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm and water, and colloidal silica, and the film-forming aqueous emulsion comprises an α, β-ethylenically unsaturated monomer. An emulsion obtained by emulsion polymerization of a monomer and acrylic silane or vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and If the amount of a gypsum board humidity control, characterized in that it has a configuration which is 0.5 to 30 times the mass that completely covers the synthetic resin particles.

  In the humidity control gypsum board of the present invention, the printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition has a particle size of A film-forming aqueous emulsion composed of 0.03 to 10 μm of synthetic resin particles and water and colloidal silica are the main components, and the film-forming aqueous emulsion comprises an α, β-ethylenically unsaturated monomer and acrylsilane or An emulsion obtained by emulsion polymerization with vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and the amount of the colloidal silica blended completely with the synthetic resin particles. It is preferable to have a configuration that is 0.5 to 30 times the mass of coating.

  The present invention also provides a humidity control gypsum board in which a gypsum core material containing a moisture absorbing / releasing material is sandwiched between two base papers for gypsum board, wherein at least one of the base papers for gypsum board is paperboard. A printed pattern layer and a clear layer are laminated in the order described here, and the clear layer is formed of a porous film-forming water-dispersed composition, and the porous film-forming water-dispersed type It is a humidity control gypsum board characterized by having a composition in which the composition contains a resin emulsion having a solid content of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass.

  In the humidity control gypsum board of the present invention, the printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition has a solid content. It is preferable to have a configuration containing a resin emulsion of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass.

  In the humidity control gypsum board of the present invention, the clear layer preferably has an average film thickness of 2 to 50 μm.

  According to the present invention, as a base paper for a gypsum board used for the production of a gypsum board, a printed pattern is applied to the surface of the paperboard, and a clear layer having a surface property such as abrasion resistance and tape peeling resistance is provided thereon. When using the base paper for gypsum board formed, the manufacturing method of the gypsum board improved in the production efficiency which can shorten drying time compared with the past is provided. In addition, according to the present invention, it is possible to provide a humidity control gypsum board having excellent surface properties such as design properties, abrasion resistance and tape peel resistance, humidity control properties, and gas adsorption properties.

Next, the present invention will be described in more detail with reference to preferred embodiments of the invention.
As a result of intensive investigations to solve the problems in the method for producing a gypsum board using a base paper for gypsum board in which a clear layer is formed by a conventional resin composition, the present inventors have obtained a porous film-forming water dispersion composition described later. It has been found that by using a base paper for gypsum board having a clear layer formed by a product, the production efficiency of a gypsum board having a cosmetic finish having sufficient surface properties can be improved. That is, a film formed by a porous film-forming water-dispersed composition described later becomes a porous continuous film in which fine pores having a pore diameter of about 0.01 to 0.5 μm are uniformly formed. For this reason, since the base paper for gypsum board which has the clear layer comprised by this film | membrane becomes a thing excellent in moisture permeability and air permeability, when manufacturing a gypsum board using this base paper for gypsum board, manufacture The drying time at the time can be shortened compared to the conventional case. In addition, even when the film is formed to a certain extent thick, fine pores that are continuous in the thickness direction are formed. Therefore, the gypsum board formed using the base paper maintains moisture permeability and air permeability. However, sufficient surface properties such as abrasion resistance and tape peel resistance are imparted to the gypsum board.

Hereinafter, the manufacturing method of the gypsum board of this invention is demonstrated.
The gypsum board manufacturing method of the present invention sandwiches a gypsum slurry mainly composed of calcined gypsum serving as a gypsum core material and water between two base papers for gypsum board, molded into a predetermined shape, and cured, In the method for producing gypsum board to be dried, a base paper for gypsum board in which a clear layer is formed with a porous film-forming water-dispersed composition described later is used. Therefore, the gypsum board production method of the present invention is basically the same as the known gypsum board production method except that a specific base paper for gypsum board is used. The gypsum board may be manufactured by using a gypsum board base paper in which a clear layer is formed with a porous film-forming water-dispersed composition described later on at least one of the gypsum board paper.

  Furthermore, the method for producing a gypsum board of the present invention is particularly effective in producing a humidity control gypsum board comprising a hygroscopic material in a gypsum core material. In other words, the moisture-absorbing / releasing material absorbs a large amount of moisture, so that moisture conditioning gypsum board contains more moisture than normal gypsum board in the stage before the drying process during the production of gypsum board. The effect obtained by shortening the drying time in the manufacturing process of gypsum board is great.

  The base paper for gypsum board that characterizes the present invention is formed by laminating a printed pattern layer and a clear layer on a paper board in the order described above, and the clear layer is formed by a porous film-forming water-dispersed composition described later. Has been. As described above, the film formed by the later-described porous film-forming water-dispersed composition is a porous continuous film in which a large number of uniform fine pores are formed. The clear layer has appropriate moisture permeability and gas permeability. Further, since the paperboard originally has moisture permeability and gas permeability, the base paper for gypsum board provided with the clear layer itself has moisture permeability and gas permeability. For this reason, if a gypsum board is manufactured using the said base paper for gypsum boards, the drying time at the time of manufacture can be shortened. Further, by using the same porous film-forming water-dispersed composition as that used for forming the clear layer as the ink binder used for forming the printed pattern layer of the above base paper, the moisture permeability of the base paper and Air permeability can be improved and the said subject can be solved.

  There is no restriction | limiting in particular about the structure especially in the said paperboard, For example, paperboards, such as a 2 layer structure which consists only of a surface layer and a back layer, and a 3 layer structure which consists of a surface layer, a middle layer, and a back layer, can be used. Moreover, each said layer can also be made into the laminated structure which consists of two or more layers. The back layer of the paperboard is adhered to a gypsum core material, and a printed pattern layer and a clear layer are laminated on the surface layer.

  There is no restriction | limiting in particular as a raw material of the said paperboard, Any conventionally well-known thing can be used. For example, kraft pulp, kraft pulp waste paper, newspaper waste paper, magazine waste paper, corrugated waste paper or deinked waste paper can be used, and these can be used alone or in combination. The paperboard is produced, for example, by using the above-mentioned raw materials and making paper by a conventional method using a multilayer paper machine.

The basis weight of the paperboard is not particularly limited, is preferably ^{100g / m 2 ~350g / m 2} . If it is less than 100 g / m ² , the strength as a base paper for gypsum board will be weak, and if it exceeds 350 g / m ² , the cost performance will be poor. Further, the basis weight of the paperboard, taking into account also the point of moisture permeability and air permeability of the base paper, it is, particularly preferably ^{100g / m 2 ~250g / m 2} .

  The printed pattern layer is provided on the surface of the paperboard, and the printed pattern layer imparts design properties to the gypsum board. The printed pattern layer is formed by a known printing method, for example, gravure printing, flexographic printing, screen printing, or the like, using an ink obtained by adding a pigment or the like to a binder. In addition, the binder of the printing ink for forming the printed pattern layer is not particularly limited when the printed pattern layer is formed with a small area that has little influence on the moisture permeability and gas permeability of the base paper, and a conventionally known ink. Binders can be used. From the viewpoint of further improving the moisture permeability and gas permeability of the base paper, it is more preferable to use a porous film-forming water-dispersed composition described later as an ink binder. In particular, when the printed pattern layer is formed in a large area by, for example, full-surface printing, the moisture permeability and gas permeability of the base paper are remarkably hindered with an ink using a normal binder. It is preferred to use the formed water-dispersed composition as an ink binder. In addition, the pigment in the ink is not particularly limited, and a known pigment can be used. Further, the ink may contain additives such as a viscosity modifier and a filler depending on required properties. it can.

  The clear layer is formed on the printed pattern layer of the paperboard using a porous film-forming water-dispersed composition described later. As described above, since the clear layer formed of the composition is porous, moisture permeability and gas permeability of the base paper for gypsum board can be ensured. In addition, by increasing the coating amount of the composition and forming the clear layer to an appropriate thickness, the base paper has excellent surface properties such as high abrasion resistance, tape peel resistance, and the like. It can be given in combination with air permeability. Moreover, there is no restriction | limiting in particular in the coating method of the said composition, A conventionally well-known method can be used, for example, a gravure coat, a roll coat, a spray coat etc. can be used. Drying after applying the composition may be natural drying or artificially heat-dried, but is preferably equal to or higher than the minimum film-forming temperature of the copolymer (resin) in the composition. Moreover, it is preferable that the average film thickness of the clear layer formed with the said composition is 2 micrometers or more and 50 micrometers or less. When the average film thickness is less than 2 μm, the abrasion resistance and tape peel resistance are inferior compared to the above range. On the other hand, even when the clear layer is formed thick, moisture permeability and air permeability can be secured, but when the average film thickness exceeds 50 μm, the cost performance of the gypsum board is poor. It becomes. Furthermore, the average film thickness of the clear layer is more preferably 4 μm or more and 30 μm or less.

  In the present invention, the formation of a clear layer or, if necessary, the porous film-forming water-dispersed composition used as a binder for printing picture layer forming ink will be described in detail. One embodiment of the composition is mainly composed of a film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm, water, and colloidal silica, and the film-forming aqueous emulsion comprises α, An emulsion obtained by emulsion polymerization of a β-ethylenically unsaturated monomer and acrylic silane or vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, The blending amount is 0.5 to 30 times the mass of completely covering the synthetic resin particles. The porous film-forming water-dispersed composition having the above-described configuration is disclosed in, for example, Japanese Patent Publication No. 7-110906, and can be synthesized by itself, or can be synthesized (for example, trade name: Mobile 8020, Nichigo Movinyl Co., Ltd.) can be used.

  In the porous film-forming water-dispersed composition having the above structure, the synthetic resin particles in the composition have a silane group and are bonded to colloidal silica. Then, when the composition is dried to form a film, the synthetic resin particles are partially inhibited from being fused by the colloidal silica, and voids surrounded by the colloidal silica are generated to form a porous film. The pores of the porous film are controlled by the particle diameter of the synthetic resin particles, and the particle diameter is within a range of 0.03 μm to 10 μm. . In order to obtain uniform pores, the synthetic resin particles preferably have a substantially uniform particle size.

  Moreover, the particle size of colloidal silica needs to be 1/3 or less of the size of the synthetic resin particles, and even if colloidal silica having a particle size exceeding 1/3 is used, a porous film cannot be obtained. Particularly preferably, the particle size of colloidal silica is 0.01 μm or less. In addition, the amount of colloidal silica is required to be 0.5 to 30 times the mass covering the synthetic resin particles, and when the amount is less than 0.5 times or more than 30 times, The vacancies cannot be obtained or the vacancies cannot be obtained uniformly.

  The film-forming aqueous emulsion can be obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer and acrylic silane or vinyl silane using a polymerization catalyst in the presence of an emulsifier. In addition, the emulsion is obtained by adding a silane compound having reactivity with the functional group to an emulsion obtained by emulsion polymerization using an α, β-ethylenically unsaturated monomer having a functional group instead of acrylic silane or vinyl silane. It can also be obtained by a reaction method. Considering this point, the latter is more likely to be present near the surface of the copolymer particles (externally) than when the silane groups are uniformly present in the synthetic resin. Emulsions obtained by the method are preferred.

  The α, β-ethylenically unsaturated monomer is not particularly limited, and examples thereof include acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. One or more of methacrylic acid esters such as ethyl methacrylate, acrylonitrile, methacrylonitrile, styrene, methylstyrene, chlorostyrene, and the like can be used. In particular, a monomer in which a monomer having a high glass transition temperature and a monomer having a low glass transition temperature are combined is preferable.

  The monomer can be copolymerized with other monomers, for example, unsaturated carboxylic acid other than acrylic acid ester and methacrylic acid ester such as methyl crotonic acid, ethyl crotonic acid, dibutyl maleate and diethyl fumarate. 1 type such as vinyl ester, vinyl chloride, vinylidene chloride, ethylene or the like such as acid ester or unsaturated polyvalent carboxylic acid ester, vinyl acetate, vinyl ester of saturated carboxylic acid branched at α-position such as vinyl 2-propionate Two or more kinds can be used.

  Examples of the α, β-ethylenically unsaturated monomer having a functional group include unsaturated carboxylic acids such as acrylic acid and methacrylic acid or unsaturated polycarboxylic acid derivatives, unsaturated carboxylic acid amides such as acrylamide, and N-methylol. One or more of N-methylol unsaturated carboxylic acid amides such as acrylamide, unsaturated glycidyl compounds such as glycidyl acrylate, alkylolized unsaturated compounds, diallyl phthalate, divinylbenzene or diallyl compounds. The α, β-ethylenically unsaturated monomer having a functional group can be used in combination at 30% by mass or less of the α, β-ethylenically unsaturated monomer.

  As the above-mentioned acrylic silane or vinyl silane, a hydrolyzable type is suitable. For example, vinyl trimethoxy silane, vinyl triethoxy silane, γ-methacryloxypropyl trimethoxy silane, etc. can be used, especially copolymerization. From the viewpoint of properties, γ-methacryloxypropyltrimethoxysilane and the like are preferable. The use ratio of the acrylic silane or vinyl silane is suitably 0.5 to 15 parts by mass when the total mass of the α, β-ethylenically unsaturated monomer and the acrylic silane or vinyl silane is 100 parts by mass. . Preferably, it is 2.0-10 mass parts.

  As the emulsifier, for example, a polymerizable emulsifier or a non-polymerizable emulsifier such as an alkali salt of alkylallylsulfosuccinate or a sodium salt of alkylphenyl ether sulfonic acid can be used. From the viewpoint of water resistance, a polymerizable emulsifier is preferable. 0.5-10 mass parts is suitable with respect to 100 mass parts of all monomers, and, as for the usage-amount of a polymerizable emulsifier, Preferably it is 1-5 mass parts.

  The method for emulsion polymerization is not particularly limited, and the monomer charging method may be a batch method or a continuous feeding method. Moreover, after superposing | polymerizing a part previously, the system which sends in the remainder continuously may be used. The monomer to be continuously fed may be used as it is, but a method of feeding it as a monomer emulsion using water and an emulsifier is very suitable. In addition, high-temperature polymerization or redox polymerization can be used for producing the film-forming aqueous emulsion.

  As the reactive silane compound, aminosilane and / or epoxysilane is used. Aminosilane is particularly effective for an aqueous emulsion of a copolymer into which a glycidyl group or a carboxyl group is introduced. For example, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane can be used. Epoxysilane is particularly effective for aqueous copolymer emulsions having amino groups or carboxyl groups introduced therein, such as 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexane) ethyl. Trimethoxysilane or the like can be used.

  Examples of the colloidal silica include ultrafine silica sol dispersed in water in a colloidal form, and ultrafine powder silica.

  In another embodiment of the porous film-forming water-dispersed composition, the composition comprises a resin emulsion having a solid content of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass. It has the composition to contain.

  When the blended amount (solid content) of the resin emulsion in the porous film-forming water-dispersed composition having the above structure is less than 60% by mass, the surface properties (abrasion resistance) of the clear layer formed by the composition Etc.) is insufficient, and when it exceeds 95% by mass, the moisture permeability and gas permeability of the clear layer are insufficient. Further, when the blending amount (solid content) of the moisture permeability imparting agent is less than 5% by mass, the moisture permeability and gas permeability of the clear layer become insufficient, and when it exceeds 40% by mass, Since tack becomes strong, it is not preferable.

  The resin constituting the resin emulsion is not particularly limited, and examples thereof include a vinyl acetate resin, an ethylene-vinyl acetate resin (EVA resin), an acrylic resin, a urethane resin, and an acrylic silicon resin. And at least one selected from these groups can be used.

  The moisture permeability-imparting agent is a material for imparting moisture permeability and air permeability by making a film formed of the composition having the above-described configuration containing the moisture permeability-imparting agent into a porous continuous film. .

  Examples of the moisture permeability-imparting agent include water glass, silicone resin emulsion, calcium stearate or aluminum stearate based on alkali metal silicate such as lithium silicate, sodium silicate, potassium silicate or cesium silicate. it can. Preferably, it is water glass. Further, water glass mainly composed of lithium silicate, which has good water resistance of the formed film, is particularly preferable. The moisture permeability imparting agent can be used in the form of a solid, an aqueous solution or a water dispersion.

  In the above-described porous film-forming water-dispersed composition, if it is an amount that does not impair the moisture permeability and gas permeability of the film formed from the composition, a colorant, a thickener, an antiseptic, an anticorrosive, Additives such as fluorescent agents, fragrances, and deodorants can be appropriately blended.

  The humidity control gypsum board of the present invention is a humidity control gypsum board in which a gypsum core material containing a moisture absorbing / releasing material is sandwiched between two base papers for gypsum board, at least one of the base papers for gypsum board However, the printed pattern layer and the clear layer are laminated on the surface of the paperboard in the order described here, and the clear layer is formed from the porous film-forming water-dispersed composition. And The above humidity control gypsum board has a clear layer formed with a specific porous film, so even if the clear layer is formed with a film thickness that can impart surface properties such as abrasion resistance and tape peel resistance, it is excellent. High humidity control and gas adsorption. Moreover, the humidity control gypsum board of the present invention using the porous film-forming water-dispersed composition as a binder for the printing ink for forming the printed pattern layer has further improved humidity control and gas adsorption. It will be a thing. The average film thickness of the clear layer of the humidity control gypsum board is preferably 2 μm or more and 50 μm or less. The average film thickness is more preferably 4 μm or more and 30 μm or less.

  The hygroscopic material used for the humidity control gypsum board of the present invention is a material having humidity control and / or gas adsorption, and any conventionally known material can be used. For example, siliceous shale, activated carbon, zeolite or silica gel can be used, and these can be used alone or in combination. The gypsum board may contain various additives such as a water reducing agent, a gypsum curing regulator, a reinforcing fiber, a foaming agent, a lightweight aggregate, or an adhesion aid in the gypsum core material.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, comparative examples, and reference examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

<Preparation of porous film-forming water-dispersed composition>
A mixed monomer composed of 70 parts by mass of butyl acrylate and 30 parts by mass of methyl methacrylate was dropped into an aqueous solution in which 2 parts by mass of sodium alkylphenyl ether sulfonate (non-polymerizable emulsifier) was dissolved in 107 parts by mass of water. Synthetic resin particles containing a silane group by emulsion polymerization by dropping 5 parts by mass of γ-methacryloxypropyltrimethoxysilane from the time when the remaining of the mixed monomer is reduced to 1/5. A water-based film-forming emulsion (solid content concentration 50% by mass, resin particle size 0.6 μm) was obtained.

  Next, 24 parts by mass (solid content) of an aqueous colloidal silica solution having a solid content concentration of 40% by mass and a particle size of 0.05 μm is added to 76 parts by mass (solid content) of the obtained film-forming aqueous emulsion and stirred uniformly. A porous film-forming water-dispersed composition 1 (solid content: 47.2% by mass) obtained by blending colloidal silica was obtained. In addition, the compounding quantity of colloidal silica was 1 time of the mass which coat | covers a synthetic resin particle.

  Next, to the obtained film-forming aqueous emulsion (70 parts by mass (solid content)), 30 parts by mass (solid content) of water glass made of lithium silicate is added and stirred uniformly, and a porous film formed by blending water glass. A formed water-dispersed composition 2 was obtained.

  Next, 20 parts by mass (solid content) of water glass composed of lithium silicate is added to 80 parts by mass (solid content) of the obtained film-forming aqueous emulsion, and the mixture is uniformly stirred, and a porous film obtained by blending water glass. A formed water-dispersed composition 3 was obtained.

<Manufacture of base paper for plasterboard>
A small-sized printed pattern layer having moisture permeability and air permeability was formed on a paperboard having a basis weight of 200 g / m ² using a gravure printing machine. Next, the porous film-forming water-dispersed composition 1 (solid content: 47.2% by mass) was applied onto the surface of the printed pattern layer using a roll coater so that the average film thickness after drying was 4 μm. The base paper 1 for gypsum board was produced by drying for 30 minutes at a drying temperature of 50 ° C. to form a clear layer.

  Next, the coating amount of the porous film-forming water-dispersed composition 1 is changed from the coating amount at which the average film thickness is 4 μm to the coating amount at which the average film thickness is 10 μm, 20 μm, 30 μm, or 50 μm. Other than that, gypsum board base papers 2 to 5 were produced under the same conditions as the base paper 1 for gypsum board.

  Next, the porous film-forming water-dispersed composition 1 in the base paper 1 for gypsum board is changed to the porous film-forming water-dispersed composition 2, and the coating amount of the composition 2 is changed to the composition. Gypsum board base papers 6 to 10 were prepared under the same conditions as the base paper 1 for gypsum board except that the average film thickness after coating and drying 2 was 4 μm, 10 μm, 20 μm, 30 μm or 50 μm. .

  Next, the porous film-forming water-dispersed composition 1 in the base paper 1 for gypsum board is changed to the porous film-forming water-dispersed composition 3, and the coating amount of the composition 3 is changed to the composition. Gypsum board base papers 11 to 15 were prepared under the same conditions as the base paper 1 for gypsum board except that the average film thickness after coating and drying 3 was 4 μm, 10 μm, 20 μm, 30 μm or 50 μm. .

  Next, the porous film-forming water-dispersed composition 1 in the base paper 1 for gypsum board is changed to the film-forming aqueous emulsion (acrylic resin emulsion), and the amount of the emulsion applied is applied to the emulsion. Gypsum board base papers 16 to 20 were prepared under the same conditions as the base paper 1 for gypsum board except that the average film thickness after drying was 4 μm, 10 μm, 20 μm, 30 μm, or 50 μm. In addition, the base paper in which the clear layer was not formed in the base paper 1 for gypsum board was produced, and it was set as the base paper 21 for gypsum board.

  The obtained gypsum board base papers 1 to 21 were subjected to the following tests. The obtained results are shown in Tables 1 to 4. In the table below, “◯” indicates excellent, “Δ” indicates good, and “×” indicates poor.

(Abrasion resistance test)
The surface of the base paper for gypsum board was visually checked for the state after 1,000 rotations using a Taber abrasion tester (abrasion wheel CS-17, load 500 g), and evaluated according to the following criteria.
○: There are no wear marks or scratches.
Δ: Slightly worn or scratched.
X: There are remarkable wear marks or scratches.

(Tape peel resistance test)
After the cellophane tape was pressure-bonded to the clear layer of the base paper for gypsum board, it was strongly peeled off at an angle of 90 degrees, and the state of the clear layer was visually confirmed and evaluated according to the following criteria.
○: The clear layer is hardly peeled off.
Δ: Clear layer is slightly peeled off.
X: Most of the clear layer is peeled off.

(Air permeability test)
The air permeability of the base paper for gypsum board was measured by a method based on JISP8117.

(Moisture permeability test)
The moisture permeability of the base paper for gypsum board was measured by a method based on the JISA1324 cup method.

※原紙１７〜２０の透気度試験は、石膏ボード用原紙の透気性が悪く計測できなかった。

* In the air permeability test of the base papers 17 to 20, the air permeability of the base paper for gypsum board was poor and could not be measured.

  As a result of the above test, the gypsum board base papers 1 to 15 in which the clear layer is formed from the porous film-forming water-dispersed composition have good wear resistance and tape peel resistance, and also have air permeability and moisture permeability. It was confirmed to be excellent. On the other hand, gypsum board base papers 16 to 20 in which a clear layer is formed by a film-forming aqueous emulsion (emulsion of acrylic resin) have good abrasion resistance and tape peel resistance, but have poor gas permeability and moisture permeability. The gypsum board base paper 21 that is confirmed to be sufficient and has no clear layer has good air permeability and moisture permeability, but has insufficient wear resistance and tape peel resistance. Was confirmed.

<Manufacture and evaluation of gypsum board>
(Dryness test during production)
The base paper 1 for gypsum board produced as described above was sized on a table with a size of 300 mm × 300 mm and the printed pattern surface facing downward. Next, a 12 mm × 12 mm × 300 mm acrylic resin presser plate was placed on the four ends of the base paper 1 to create a 300 mm square box shape. A gypsum slurry mixed with 70 parts by mass of calcined gypsum, 30 parts by mass of siliceous shale and 150 parts by mass of water is poured into the box shape, and a 300 mm × 300 mm gypsum board base paper 1 is placed with the printed pattern surface facing upward. The plaster slurry was cured (in a state where the plaster and the base paper 1 were bonded). The obtained dry gypsum board 1 having a thickness of 12 mm and a width of 300 mm × 300 mm is made 50 mm × 50 mm in size, and the four sides are sealed with aluminum tape to block moisture and air permeability at the sides. Thus, a test specimen of the gypsum board 1 was obtained. After measuring the mass (W ₀ ) of the obtained specimen, it was put in a 200 ° C. hot air dryer and dried. The mass (W _n ) of the specimen was measured at regular intervals, and the mass reduction rate (%) was calculated using the following formula. The results obtained are shown in Table 5.
Mass reduction rate (%) = (W _n −W ₀ ) / W ₀ × 100

  Moreover, also about the base papers 2-4, 6-9, 11-14, 16-19, and 21 for gypsum board, it is the same as the case of the base paper 1 for gypsum board, and gypsum boards 2-4, 6-9, 11 -14, 16-19, and 21 specimens were prepared, and the mass reduction rate (%) was calculated. The obtained results are shown in Tables 5-8.

  When the gypsum board is produced using the gypsum board base paper in which the clear layer is formed by the porous film-forming water-dispersed composition, the above base paper is resistant to abrasion and tape. It was confirmed that drying can be performed efficiently during production, despite the formation of a clear layer having a property. In addition, the humidity control gypsum board produced using the above base paper has good air permeability and moisture permeability test results of the above base paper, so that the moisture absorbing / releasing material contained in the gypsum core material is It can be said that the humidity control and gas adsorption properties can be effectively exhibited.

[Other embodiments]
A printing pattern layer printed on the entire surface using a flexographic printing machine with ink having a binder of the porous film-forming water-dispersed composition 1 (solid content: 47.2% by mass) on a paperboard having a basis weight of 200 g / m ^2. Then, a clear layer was formed using the porous film-forming water-dispersed composition 1 to obtain a base paper 22 for gypsum board. Then, the gypsum board 22 was created on the same conditions as the said method. About the said base paper 22 for gypsum board or the said gypsum board 22, when it carried out similarly to the above and carried out abrasion resistance, tape peeling resistance, air permeability, moisture permeability, and the drying test at the time of manufacture, all evaluations were carried out. Good results were obtained for the items.

Moreover, after forming a printing pattern layer of a full surface printing on a paperboard with a basis weight of 200 g / m ² using a flexographic printing machine with an ink having the porous film-forming water-dispersed composition 2 as a binder, A clear layer was formed using the water-based film-forming water-dispersed composition 2 to obtain a base paper 23 for gypsum board. Then, the gypsum board 23 was created on the conditions similar to the said method. About the said base paper 23 for gypsum board or the said gypsum board 23, when it carried out similarly to the above and carried out abrasion resistance, tape peeling resistance, air permeability, moisture permeability, and the drying test at the time of manufacture, all evaluations were carried out. Good results were obtained for the items.

  According to the present invention, as a base paper for a gypsum board, a printed pattern is applied to the surface of the paperboard, and a clear layer having a surface physical property such as abrasion resistance and tape peeling resistance is formed thereon. By using the base paper, it is possible to shorten the drying time at the time of manufacturing the gypsum board and provide a method for manufacturing the gypsum board with high production efficiency. Further, according to the present invention, it is possible to provide a humidity control gypsum board excellent in surface properties such as design properties, abrasion resistance and tape peel resistance, humidity control properties, and gas adsorption properties. Therefore, the gypsum board manufactured by this invention can be used suitably as interior finishing materials, such as a wall, a ceiling, or accommodation, and also at low cost.

Claims (10)

  In the gypsum board manufacturing method in which a gypsum slurry mainly composed of calcined gypsum serving as a gypsum core and water is sandwiched between two base papers for gypsum board, molded into a predetermined shape, cured, and then dried. At least one sheet of base paper for gypsum board is formed by laminating a printed pattern layer and a clear layer on the surface of the paper board in the order described above, and the clear layer is formed of a porous film-forming water-dispersed composition. The porous film-forming water-dispersed composition is composed mainly of a film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm and water and colloidal silica, and the film-forming aqueous emulsion. Is an emulsion obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer and acrylic silane or vinyl silane, and the colloidal silica is the synthetic resin particle A gypsum board having a particle size of 1/3 or less, and further having a constitution in which the amount of the colloidal silica is 0.5 to 30 times the mass that completely covers the synthetic resin particles Manufacturing method.   The printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is a synthetic resin particle having a particle size of 0.03 to 10 μm. And a water-based film-forming emulsion composed of water and colloidal silica, and the film-forming water-based emulsion was obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer and acrylsilane or vinylsilane. It is an emulsion, and the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and the blending amount of the colloidal silica is 0.5 to 0.5% of the mass for completely covering the synthetic resin particles. The manufacturing method of the gypsum board of Claim 1 which has a structure which is 30 times.   In the gypsum board manufacturing method in which a gypsum slurry mainly composed of calcined gypsum serving as a gypsum core and water is sandwiched between two base papers for gypsum board, molded into a predetermined shape, cured, and then dried. At least one sheet of base paper for gypsum board is formed by laminating a printed pattern layer and a clear layer on the surface of the paper board in the order described above, and the clear layer is formed of a porous film-forming water-dispersed composition. The porous film-forming water-dispersed composition contains a resin emulsion having a solid content of 60 to 95% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass. A method for producing a gypsum board.   The printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is a resin emulsion having a solid content of 60 to 95% by mass. The manufacturing method of the gypsum board of Claim 3 which has a structure containing the moisture permeability imparting agent whose solid content is 5-40 mass%.   The average film thickness of the said clear layer is 2-50 micrometers, The manufacturing method of the gypsum board in any one of Claims 1-4.   In a humidity control gypsum board in which a gypsum core material containing a hygroscopic material is sandwiched between two base papers for gypsum board, at least one of the base papers for gypsum board is printed on the surface of the board. And the clear layer are laminated in the order described here, and the clear layer is formed of a porous film-forming water-dispersed composition, and the porous film-forming water-dispersed composition has a particle size of A film-forming aqueous emulsion composed of 0.03 to 10 μm of synthetic resin particles and water and colloidal silica are the main components, and the film-forming aqueous emulsion comprises an α, β-ethylenically unsaturated monomer and acrylsilane or An emulsion obtained by emulsion polymerization with vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and the amount of the colloidal silica is as described above. Humidity gypsum board characterized by having a structure which is 0.5 to 30 times the mass that completely covers the synthetic resin particles.   The printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is a synthetic resin particle having a particle size of 0.03 to 10 μm. And a water-based film-forming emulsion composed of water and colloidal silica, and the film-forming water-based emulsion was obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer and acrylsilane or vinylsilane. It is an emulsion, and the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and the blending amount of the colloidal silica is 0.5 to 0.5% of the mass for completely covering the synthetic resin particles. The humidity control gypsum board of Claim 6 which has a structure which is 30 times.   In a humidity control gypsum board in which a gypsum core material containing a hygroscopic material is sandwiched between two base papers for gypsum board, at least one of the base papers for gypsum board is printed on the surface of the board. And the clear layer are laminated in the order described here, and the clear layer is formed of a porous film-forming water-dispersed composition, and the porous film-forming water-dispersed composition has a solid content. A humidity control gypsum board comprising a resin emulsion having a solid content of 5 to 40% by mass and a moisture permeability imparting agent having a solid content of 5 to 40% by mass.   The printed pattern layer is formed of a printing ink having a porous film-forming water-dispersed composition as a binder, and the porous film-forming water-dispersed composition is a resin emulsion having a solid content of 60 to 95% by mass. The moisture-conditioning gypsum board according to claim 8, comprising a moisture permeability imparting agent having a solid content of 5 to 40% by mass.   The humidity control gypsum board according to any one of claims 6 to 9, wherein an average film thickness of the clear layer is 2 to 50 µm.