WO2020195551A1

WO2020195551A1 - Hygroscopic coating agent, hygienic material molded body having dry film formed thereon by coating agent, and method for manufacturing coating agent

Info

Publication number: WO2020195551A1
Application number: PCT/JP2020/008446
Authority: WO
Inventors: 秀治辻内; 佐々木　寛人; 友記岡田; 勉古川
Original assignee: 大阪印刷インキ製造株式会社; 大王製紙株式会社
Priority date: 2019-03-27
Filing date: 2020-02-28
Publication date: 2020-10-01
Also published as: TWI816985B; JP2020158662A; JP7329785B2; TW202034871A

Abstract

[Problem] An objective of the present invention is to provide: a coating agent that can form a hygroscopic dry film by being coated on a moisture-permeable waterproof film; a hygienic material molded body on which the coating agent is formed; and a method for manufacturing the coating agent. [Solution] A coating agent according to the present invention forms a hygroscopic dry film, the coating agent comprising cellulose nanofibers, an acid-containing copolymer and a solvent, the cellulose nanofibers and the acid-containing copolymer being dispersed by the solvent, the acid-containing copolymer being formed from at least one (meth) acrylate monomer and at least one vinyl monomer, and the acid-containing copolymer being one acid-containing copolymer having an acid value of 50-150mgKOH/g and a glass translation point of 20-50°C.

Description

A coating agent having hygroscopicity, a molded product for sanitary materials in which a dry film is formed by the coating agent, and a method for producing the coating agent.

The present invention relates to a hygroscopic coating agent, a molded product for sanitary materials in which a hygroscopic dry film is formed by the coating agent, and a method for producing the coating agent.

Absorbent molded products are used for disposable diapers and the like, but the absorbent molded products are required to have excellent breathability and moisture permeability not only to absorb water but also to prevent stuffiness after urination. Has been done. In addition to preventing stuffiness, there are a number of diapers that improve the feel of the part that comes into contact with the skin, and sheets and the like that combine a breathable film and a non-woven fabric are used (Patent Documents). See 1 and 2).

However, if the air permeability and moisture permeability of the disposable diaper are increased in order to prevent stuffiness after urination, the moisture permeated from the disposable diaper to the outside is absorbed by the clothes and the like, causing a problem that the clothes become moist.

Japanese Unexamined Patent Publication No. 2008-21382 Japanese Patent Application Laid-Open No. 178- Japanese Unexamined Patent Publication No. 2018-154699 Japanese Patent No. 6350569 Japanese Unexamined Patent Publication No. 2018-119073

In order to solve such problems in conventional disposable diapers and the like, the present invention provides hygroscopicity, which can impart hygroscopicity to a molded body for sanitary materials such as disposable diapers without impairing breathability and moisture permeability. It is an object of the present invention to provide a coating agent having a coating agent, a molded body for a sanitary material in which a dry film having hygroscopicity is formed by the coating agent, and a method for producing the coating agent.

The coating agent of the present invention is a coating agent that forms a dry film having a hygroscopic property, and contains a cellulose nanofiber, an acid-containing copolymer, and a solvent, and the cellulose nanofiber and the acid-containing copolymer are produced by the solvent. Dispersed, the acid-containing copolymer is formed from at least one (meth) acrylate-based monomer and at least one vinyl-based monomer, and the acid-containing copolymer has an acid value of 50 to 150 mgKOH / g. It is characterized by being one kind of acid-containing copolymer having a glass transition point of 20 to 50 ° C.

The coating agent of the present invention, a coating agent to form a dried coating having a hygroscopic, cellulose nanofibers, acid-containing copolymers, and includes a solvent, the cellulose nanofibers are dispersed by the solvent, containing said acid The copolymer is dissolved or dispersed by the solvent, the acid-containing copolymer is formed from at least one (meth) acrylate-based monomer, and at least one vinyl-based monomer, and the acid-containing copolymer has an acid value. It is characterized in that it is at least two kinds of acid-containing copolymers having a glass transition point of 50 to 300 mgKOH / g and a glass transition point of −10 to 150 ° C.

The coating agent contains the cellulose nanofibers in a proportion of 2 to 10% by weight and the acid-containing copolymer in a proportion of 95 to 70% by weight.

The thixotropic index value (TI value) of the coating agent is preferably 10 or less.

The molded article for sanitary material of the present invention is a molded article for sanitary material in which a dry film having hygroscopicity is formed on a part of one side of a moisture-permeable waterproof film, and the dry film is formed by the coating agent. It is characterized by being.

The dry film is formed at a ratio of 30 to 70% of the flat area on one side of the breathable waterproof film.

The molded article for sanitary materials can be used as a disposable diaper.

In the method for producing a coating agent of the present invention, a dispersion of the cellulose nanofibers is prepared, the acid-containing copolymer is stirred at a speed of 50 to 1000 rpm, and the cellulose nanofibers are dispersed in the acid-containing copolymer in a stirred state. It is characterized in that the liquid is added while being beaten.

After adding an amino acid-type amphoteric surfactant or a polyvinyl acetamide-based compound to the dispersion of cellulose nanofibers, the dispersion of cellulose nanofibers can be added to the acid-containing copolymer in a stirred state.

The coating agent of the present invention is a coating agent that forms a dry film having a hygroscopic property, and contains a cellulose nanofiber, an acid-containing copolymer, and a solvent, and the cellulose nanofiber and the acid-containing copolymer are produced by the solvent. Dispersed, the acid-containing copolymer is formed from at least one (meth) acrylate-based monomer and at least one vinyl-based monomer, and the acid-containing copolymer has an acid value of 50 to 150 mgKOH / g. By using one kind of acid-containing copolymer having a glass transition point of 20 to 50 ° C., it is possible to form a dry film having hygroscopicity.

The coating agent of the present invention is a coating agent for forming a dry film having hygroscopicity, and contains cellulose nanofibers, an acid-containing copolymer, and a solvent, and the cellulose nanofibers are dispersed by the solvent and contains the acid. The copolymer is dissolved or dispersed by the solvent, the acid-containing copolymer is formed from at least one (meth) acrylate-based monomer, and at least one vinyl-based monomer, and the acid-containing copolymer has an acid value. By using at least two kinds of acid-containing copolymers having a temperature of 50 to 300 mgKOH / g and a glass transition point of −10 to 150 ° C., it is possible to form a dry film having hygroscopicity.

By containing the cellulose nanofibers in a proportion of 2 to 10% by weight and the acid-containing copolymer in a proportion of 95 to 70% by weight, sufficient coatability is ensured and a dry film having appropriate hygroscopicity is formed. It becomes possible to do.

By setting the thixotropic index value (TI value) of the coating agent to 10 or less, a coating agent having excellent coatability can be obtained.

The molded body for sanitary materials of the present invention is a molded body for sanitary materials in which a dry film having hygroscopicity is formed on a part of one side of a moisture-permeable waterproof film, and the dry film is formed by the coating agent. This makes it possible to have a desired hygroscopicity without impairing the moisture permeability and waterproofness of the moisture-permeable waterproof film.

By using the molded product for sanitary materials as a disposable diaper, the moisture that has permeated the disposable diaper can be absorbed by the dry film, and the moisture is absorbed by the clothes or the like to prevent the clothes from feeling damp. It is possible to improve the usability of disposable diapers.

In the method for producing a coating agent of the present invention, a dispersion of the cellulose nanofibers is prepared, the acid-containing copolymer is stirred at a speed of 50 to 1000 rpm, and the cellulose nanofibers are dispersed in the acid-containing copolymer in a stirred state. By adding the liquid while performing the beating treatment, the cellulose nanofibers can be appropriately dispersed and the coatability of the coating agent can be ensured.

It is a top view of the molded article for sanitary material of this invention.

The hygroscopic coating agent of the present invention, the molded article for sanitary materials on which a hygroscopic dry film is formed, and the method for producing the coating agent will be described in detail below with reference to Examples.

First, the coating agent of the present invention will be described. The coating agent of the present invention is a coating agent that forms a film having hygroscopicity when a dry film is formed, and contains cellulose nanofibers, an acid-containing copolymer, and a solvent, and the cellulose nanofibers are said to be said. Dispersed by a solvent, the acid-containing copolymer is dissolved or dispersed by the solvent. The acid-containing copolymer is formed from at least one (meth) acrylate-based monomer and at least one vinyl-based monomer.

When only one type of the acid-containing copolymer is used as the coating agent, an acid-containing copolymer having an acid value of 50 to 150 and a glass transition point of 20 to 50 ° C. is used. When two or more kinds of the acid-containing copolymers are used as the coating agent, an acid-containing copolymer having an acid value of 50 to 300 and a glass transition point of −10 to 150 ° C. is used. By using such an acid-containing copolymer, the coatability of the coating agent can be ensured. When an acid-containing copolymer having a low acid value is used, the coating agent agglomerates and cannot be used as a coating agent. The (meth) acrylate-based monomer and vinyl-based monomer used in the acid-containing copolymer are not particularly limited, as long as the acid-containing copolymer satisfies the acid value and the glass transition point as described above. It is possible to use a general monomer.

The cellulose nanofibers are used to improve the hygroscopicity of the dry film formed by the coating agent, and by using cellulose nanofibers having a fiber average width of several nm to several hundred nm, the specific surface area is increased. Due to the influence of the hydroxyl groups present on the surface, it becomes possible to have high hygroscopicity when the dry film is formed.

The form of the cellulose nanofibers can be powdery, aqueous dispersion, slurry, paste, gel, etc., and is not particularly limited, but dispersibility when added to the coating agent. From the viewpoint of fluidity and the thixotropic index value (TI value) of the coating agent described later, it is preferable to use the form of an aqueous dispersion for the cellulose nanofibers.

The type of the cellulose nanofibers is not particularly limited, and a cellulose nanofiber obtained by mechanically defibrating the raw material pulp, a chemical method before defibration, a pretreated cellulose nanofiber, or the like can be used. it can. As pretreatment, the cellulose nanofibers are hydrolyzed with an acid (acid treatment), hydrolyzed with an enzyme (enzyme treatment), swelled with an alkali (alkaline treatment), and oxidized with an oxidizing agent (oxidation). Treatment), reduction of polysaccharide with a reducing agent (reduction treatment), and the like can also be used.

The physical property value of the cellulose nanofibers is not particularly limited, but from the viewpoint of controlling the TI value (viscostropic index) of the coating agent, B of the dispersion liquid (concentration 1.5%) of the cellulose nanofibers. The mold viscosity is preferably 20,000 cps or less, more preferably 5,000 cps or less. Limiting the B-type viscosity of the dispersion of cellulose nanofibers facilitates the adjustment of the TI value of the coating agent, and makes it easy to apply the coating agent to the base film to which the coating agent is applied, or to dry the coating agent at the time of coating. It has a good effect from a sexual point of view.

As the solvent, water or a water-alcohol-based mixed solvent can be used, and the weight ratio of the water: alcohol-based mixed solvent is preferably 100: 0 to 50:50.

The coating agent preferably contains the cellulose nanofibers in a proportion of 2 to 10% by weight and the acid-containing copolymer in a proportion of 95 to 70% by weight. If the proportion of cellulose nanofibers is large, the coatability of the coating agent may deteriorate and coating may not be possible. If the proportion of cellulose nanofibers is too small, the hygroscopicity will be insufficient when a dry film is formed. In some cases.

The coating agent preferably has a thixotropic index value (TI value) of 10 or less, and when the TI value becomes large, the coatability of the coating agent may deteriorate and coating may not be possible.

As other components, the coating agent may be a filler, a pigment, a wax, a surface conditioner, a defoaming agent, a defoaming agent, a settling inhibitor, a thickener, a preservative, a lubricant, or a release agent, depending on the conditions of use. A mold, a water resistant agent, a cross-linking agent, a hygroscopic material other than cellulose nanofibers (CNF) (glycerin, propylene glycol, sorbitol, a highly water-absorbent resin typified by polyacrylic acid), etc. may be added as appropriate. It is possible, and it is also possible to color the coating agent by adding a pigment to form a dry film of various colors.

By containing the cellulose nanofibers and the acid-containing copolymer, the coating agent of the present invention can secure sufficient coatability as a coating agent and can form a dry film having sufficient hygroscopicity. It becomes.

Next, the method for producing the coating agent of the present invention will be described. First, a dispersion of cellulose nanofibers, an acid-containing copolymer, and a solvent are prepared. The acid-containing copolymer is placed in a stainless steel container equipped with a stirrer and stirred at a speed of 50 to 1000 rpm. A dispersion of cellulose nanofibers is placed in another stainless steel container and beaten with a high-pressure homogenizer while being added dropwise to the agitated acid-containing copolymer. When a predetermined amount of the dispersion liquid of cellulose nanofibers is dropped and stirring is completed, the coating agent is completed.

When using two or more types of acid-containing copolymers, put all the acid-containing copolymers in a stainless steel container and stir, and then drop the dispersion of the cellulose nanofibers. When an amino acid-type amphoteric surfactant or a polyvinyl acetamide-based compound is added, it is added to a dispersion of cellulose nanofibers, and then added dropwise to an acid-containing copolymer in a stirred state while beating with a high-pressure homogenizer.

When adding wax, surface conditioner, antifoaming agent, etc., add to the acid-containing copolymer in a stirred state after the dispersion liquid of cellulose nanofibers is completely added dropwise.

In this way, the method for producing a coating agent of the present invention makes it possible to ensure the coatability of the coating agent by appropriately dispersing the cellulose nanofibers.

Next, the molded article for sanitary materials of the present invention will be described. As shown in FIG. 1, in the molded product 1 for sanitary materials of the present invention, a hygroscopic dry film 2 made of the coating agent is formed on a part of one side of the moisture permeable waterproof film 3, and the dry film 2 is formed. Is formed on a part of one side of the moisture permeable waterproof film 3. The molded article 1 for sanitary materials of the present invention having such a structure can be used for disposable diapers and the like because the moisture that has passed through the moisture-permeable waterproof film 3 can be absorbed by the dry film 2.

The dry film 2 is formed by being coated on one side of the moisture-permeable waterproof film 3 and dried. The method for forming the dry film 2 is not particularly limited, but for example, it can be applied to one side of the moisture-permeable waterproof film 3 using a flexographic printing machine. From the viewpoint of ensuring the moisture permeability of the moisture-permeable waterproof film 3, the dry film 2 is preferably formed in a range of 30 to 70% of the flat area of one side of the moisture-permeable waterproof film 3. Further, regarding the thickness of the dry coating 2, it is preferable to adjust the dry coating weight of the coating agent to 0.1 to 5 μm in consideration of hygroscopicity and the like, and further, 0.3 to 5 μm. It is more preferably 2 μm. When the thickness of the dry film 2 is 0.1 μm or less, the sanitary material molded product 1 cannot obtain sufficient hygroscopicity, and when the thickness is 5 μm or more, the cost for drying the coating agent・ It is not practical considering the time.

As a method of forming the dry film 2 on a part of the moisture permeable waterproof film 3, for example, as shown in FIG. 1A, a method of forming a plurality of strips on one side of the moisture permeable waterproof film 3, FIG. Various methods can be used, such as a method of forming a plurality of strips vertically and horizontally as shown in 1 (b), and a method of forming a plurality of figures at predetermined intervals as shown in FIGS. 1 (c) and 1 (d). it can. In addition, it can be formed as characters and patterns. Then, by adding a pigment to the coating agent, the dry film 2 can be colored in various colors. Therefore, the dry film 2 is colored with a coating agent containing a pigment, and molding for the sanitary material. It is also possible to improve the design of the body 1.

As the moisture-permeable waterproof film 3, a conventional film can be used, and the film is not particularly limited, and a film having moisture permeability and waterproofness used as a molded body for sanitary materials such as disposable diapers should be used. Can be done. As the moisture-permeable waterproof film 3, for example, a microporous plastic obtained by kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet and then stretching it in a uniaxial or biaxial direction. A film can be used. As the moisture-permeable waterproof film 3, other methods such as strengthening leakage resistance by reducing the voids of fibers by applying heat or pressure, and coating with a highly water-absorbent resin or a hydrophobic resin or a water-repellent agent can be used. It is possible to use a liquid-impermeable non-woven fabric without using a plastic film, a laminated non-woven fabric in which a plastic film is provided on the surface of the non-woven fabric, a laminated sheet in which a non-woven fabric or the like is laminated on a plastic film and bonded.

Assuming that the sanitary material molded body 1 is used for a disposable diaper or the like, the moisture permeable waterproof film 3 may be a film having a moisture permeability of 6000 to 12000 g / m2 / 24 hr measured according to JIS Z0208. It is preferable to use a film of 8000 to 10000 g / m2 / 24 hr. When the sanitary material molded body 1 is used for a disposable diaper or the like, it is not possible to create a comfortable environment for stuffiness for infants if the moisture permeability is less than 6000 g / m2 / 24 hr, and if it exceeds 12000 g / m2.24 hr, urine Exudation is a problem. In order to produce a moisture-permeable waterproof film 3 having moisture permeability suitable for paper diapers and the like, an inorganic filler is kneaded into an olefin resin such as polyethylene or polypropylene to form a sheet, and then uniaxial or biaxial. When forming a microporous sheet by stretching in the direction, a method is used in which a large amount of an inorganic filler is mixed to form a large number of micropores.

When the molded body 1 for sanitary materials of the present invention is used for a disposable diaper, the moisture that has permeated the disposable diaper can be absorbed by the dry film 2, and the moisture is absorbed by the clothes or the like to make the clothes feel moist. Can be prevented and the usability can be improved.

The coating agent and the molded article for sanitary materials of the present invention will be described with reference to Examples and Comparative Examples. First, the acid-containing copolymer used for the coating agent will be described.

(Synthesis of acid-containing copolymer A aqueous dispersion)
150 parts by weight of propylene glycol methyl ether acetate is charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and heated to 145 ° C. To the reaction vessel, 2 parts by weight of dit-butyl peroxide as a polymerization initiator, 75 parts by weight of styrene as a monomer component, 12.5 parts by weight of acrylic acid, and 12.5 parts by weight of methacrylic acid were added dropwise over 2 hours. After further reacting for 40 hours, the solvent was removed by distillation under reduced pressure to obtain a styrene: acrylic acid: methacrylic acid = 6: 1: 1 (weight ratio) copolymer [1].

Next, 120 parts by weight of water, N- (1,2-dicarboxyethyl) -N-octadecylsulfone was added to a closed pressure reactor equipped with a pressure gauge, a thermometer, a stirrer, a nitrogen gas introduction pipe and two dropping tanks. 0.02 parts by weight of the tetrasodium salt of succinate, 40 parts by weight of the styrene: acrylic acid: methacrylic acid = 6: 1: 1 (weight ratio) copolymer [1], and 2 parts by weight of 25% by weight aqueous ammonia were charged. , Stirred and dissolved under the conditions of 85 ° C.

20 parts by weight of butyl acrylate, 10 parts by weight of 2-ethylhexyl acrylate, and 30 parts of styrene were charged in the first dropping tank, dropped into the reactor over 3 hours, and 30 parts by weight of water and 0.3 weight of ammonium persulfate were added to the second dropping tank. The lysate of the part was charged and added dropwise to the reactor over 4 hours. During the polymerization, the reaction vessel was adjusted to a temperature of 85 ° C. In this way, an acid-containing copolymer A aqueous dispersion having a glass transition point Tg = 30 ° C. and an acid value = 72 mgKOH / g was obtained. The solid content of the acid-containing copolymer A aqueous dispersion was about 40% by weight.

(Synthesis of acid-containing copolymer B aqueous solution)
150 parts of propylene glycol methyl ether acetate was charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and heated to 145 ° C. To the reaction vessel, 2 parts by weight of dit-butyl peroxide as a polymerization initiator, 60 parts by weight of styrene as a monomer component, 20 parts by weight of acrylic acid, and 20 parts by weight of methacrylic acid were added dropwise over 2 hours, and further 40 hours. After the reaction, 150 parts by weight of water and 5 parts by weight of 25% by weight aqueous ammonia were added to the copolymer obtained by removing the solvent by vacuum distillation, and the mixture was stirred and dissolved under the condition of 85 ° C. In this way, an aqueous solution of the acid-containing copolymer B having Tg = 115 ° C. and an acid value = 286 mgKOH / g was obtained. The solid content of the acid-containing copolymer B was about 40% by weight.

(Synthesis of acid-containing copolymer C aqueous dispersion)
120 parts by weight of water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfosuccinate in a closed pressure reactor equipped with a pressure gauge, thermometer, stirrer, nitrogen gas introduction tube and two dropping tanks. 0.02 parts by weight of the tetrasodium salt of the above, 40 parts by weight and 25 parts by weight of the copolymer [1] (styrene: acrylic acid: methacrylic acid = 6: 1: 1 (weight ratio)) synthesized at the time of preparing the acid-containing copolymer A. 2 parts by weight of% aqueous ammonia was charged and dissolved by stirring under the condition of 85 ° C.

30 parts by weight of butyl acrylate, 20 parts by weight of 2-ethylhexyl acrylate, and 10 parts of methyl methacrylate were charged in the first dropping tank, dropped into the reactor over 3 hours, and 30 parts by weight of water and 0.3 parts of ammonium persulfate were added to the second dropping tank. A heavy part of the lysate was charged and added dropwise to the reactor over 4 hours. During the polymerization, the reaction vessel was adjusted to a temperature of 85 ° C. In this way, an acid-containing copolymer C aqueous dispersion having Tg = -6 ° C. and an acid value of 72 mgKOH / g was obtained. The solid content of the acid-containing copolymer C aqueous dispersion was about 40% by weight.

(Synthesis of acid-containing copolymer D)
120 parts by weight of water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfosuccinate in a closed pressure reactor equipped with a pressure gauge, thermometer, stirrer, nitrogen gas introduction tube and two dropping tanks. 0.02 parts by weight of the tetrasodium salt of the above, 40 parts by weight and 25 parts by weight of the copolymer [1] (styrene: acrylic acid: methacrylic acid = 6: 1: 1 (weight ratio)) synthesized at the time of preparing the acid-containing copolymer A. 2 parts by weight of% aqueous ammonia was charged and dissolved by stirring under the condition of 85 ° C.

25 parts by weight of ethyl acrylate, 10 parts by weight of styrene, 20 parts by weight of α-methylstyrene, and 5 parts by weight of methyl methacrylate were charged in the first dropping tank, dropped into the reactor over 3 hours, and 30 parts by weight of water was added to the second dropping tank. A lysate of 0.3 parts by weight of ammonium persulfate was charged and added dropwise to the reactor over 4 hours. During the polymerization, the reaction vessel was adjusted to a temperature of 85 ° C. In this way, an acid-containing copolymer D having Tg = 72 ° C. and an acid value = 72 mgKOH / g was obtained. The solid content of the acid-containing copolymer D was about 40% by weight.

(Synthesis of acid-containing copolymer E)
120 parts by weight of water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfosuccinate in a closed pressure reactor equipped with a pressure gauge, thermometer, stirrer, nitrogen gas introduction tube and two dropping tanks. 0.02 parts by weight of the tetrasodium salt, 24 parts by weight, and 25 parts by weight of the copolymer [1] (styrene: acrylic acid: methacrylic acid = 6: 1: 1 (weight ratio)) synthesized at the time of preparing the acid-containing copolymer A. 2 parts by weight of% aqueous ammonia was charged and dissolved by stirring under the condition of 85 ° C.

24 parts by weight of butyl acrylate, 42 parts by weight of styrene, and 10 parts by weight of 2-ethylhexyl acrylate were charged in the first dropping tank, dropped into the reactor over 3 hours, and 30 parts by weight of water and ammonium persulfate were added to the second dropping tank. 3 parts by weight of the lysate was charged and added dropwise to the reactor over 4 hours. During the polymerization, the reaction vessel was adjusted to a temperature of 85 ° C. In this way, an acid-containing copolymer E having Tg = 22.7 ° C. and an acid value = 43 mgKOH / g was obtained. The solid content of the acid-containing copolymer E was about 40% by weight.

Next, the coating agents of Examples 1 to 10 using the acid-containing copolymers A to D and the molded article for sanitary materials formed by applying the coating agents to the film will be described.

48 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 14 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. The mixture was added dropwise to the acid-containing copolymer A aqueous dispersion at a stirring speed of 700 rpm while performing a beating treatment using the above. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Example 1 having an acid-containing copolymer content of 90.1% in the solid content was prepared. The coating agent of Example 1 uses one kind of acid-containing copolymer.

When the coating agent of Example 1 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.54. The thixotropic index value was calculated by the following formula.
TI value = Viscosity under low speed rotation at 6 rpm / Viscosity under high speed rotation at 60 rpm

The coating agent of Example 1 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded article 1 for sanitary material of Example 1. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.25 g / m2, and the dry coating thickness was 0.5 μm.

48 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) having a solid content of 3% by weight, which was mechanically disintegrated after enzymatically treating wood pulp, as an amic acid-type amphoteric surfactant, N- 0.1 part by weight of sodium salt of lauroyl-N-methylglycine and 13.9 parts by weight of water are mixed, and the acid-containing copolymer A aqueous dispersion under a stirring speed of 700 rpm is subjected to beating treatment using a high-pressure homogenizer. Dropped into. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Example 2 having an acid-containing copolymer content of 89.7% in the solid content was prepared. The coating agent of Example 2 uses one kind of acid-containing copolymer.

When the coating agent of Example 2 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. Regarding the ink foamability immediately after the adjustment, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.88.

The coating agent of Example 2 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 2 for sanitary material of Example 2. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.24 g / m2, and the dry coating thickness was 0.5 μm.

In a stainless steel container equipped with a stirrer, 8 parts by weight of the acid-containing copolymer B aqueous solution, 8 parts by weight of the acid-containing copolymer C aqueous dispersion, and 27 parts by weight of the acid-containing copolymer D aqueous dispersion are weighed, and the speed is 700 rpm. It was in a stirred state below. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 19 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. The mixture was added dropwise to the acid-containing copolymers B, C, and D mixed solution under a stirring speed of 700 rpm while performing a beating treatment using. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.7%, total. The coating agent of Example 3 having an acid-containing copolymer content of 89.1% in the solid content was prepared. The coating agent of Example 3 uses three kinds of acid-containing copolymers.

When the coating agent of Example 3 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.77.

The coating agent of Example 3 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 300-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 3 for sanitary material of Example 3. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.30 g / m2, and the dry coating thickness was 0.6 μm.

In a stainless steel container equipped with a stirrer, 8 parts by weight of the acid-containing copolymer B aqueous solution, 8 parts by weight of the acid-containing copolymer C aqueous dispersion, and 27 parts by weight of the acid-containing copolymer D aqueous dispersion were weighed at 700 rpm. It was put into a stirring state at a low speed. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) with a solid content of 3% by weight, which was mechanically disintegrated after enzymatically treating wood pulp, was prepared as polyvinylacetamide by Showa Denko Co., Ltd. "GE191- 103 ”(10% aqueous solution) and 18 parts by weight of water were mixed and added dropwise to the acid-containing copolymers B, C, and D mixed solution under a stirring speed of 700 rpm while beating with a high-pressure homogenizer. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.7%, total. The coating agent of Example 4 having an acid-containing copolymer content of 88.6% in the solid content was prepared. The coating agent of Example 4 uses three kinds of acid-containing copolymers.

When the coating agent of Example 4 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. Regarding the ink foamability immediately after the adjustment, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.02.

The coating agent 4 of Example 4 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 300-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. It was processed, dried, and wound into a roll to obtain a molded product 4 for sanitary material of Example 4. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.30 g / m2, and the dry coating thickness was 0.6 μm.

48 parts by weight of the acid-containing copolymer A aqueous dispersion prepared above was weighed in a stainless steel container equipped with a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 30 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) with a solid content of 2% by weight obtained by mechanically decomposing wood pulp, N-lauroyl-N-methylglycine as an amic acid type amphoteric surfactant 0.1 part by weight and 20.9 parts by weight of water were mixed and added dropwise to the acid-containing copolymer A aqueous dispersion at a stirring speed of 700 rpm while beating with a high-pressure homogenizer. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 2.9%, total. The coating agent of Example 5 having an acid-containing copolymer content of 92.3% in the solid content was prepared. The coating agent of Example 5 uses one kind of acid-containing copolymer.

When the coating agent of Example 5 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. Regarding the ink foamability, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 7.03.

The coating agent of Example 5 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 5 for sanitary material of Example 5. Although some blurring and ink skipping were confirmed during coating, it did not affect mass productivity. In addition, no variation in the coating amount or poor drying was confirmed. The dry coating weight of the coating agent was 0.27 g / m2, and the dry coating thickness was 0.5 μm.

48 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) having a solid content of 3% by weight, which was mechanically disintegrated after enzymatically treating wood pulp, was N- as an amic acid type amphoteric surfactant. 0.1 part by weight of sodium salt of lauroyl-N-methylglycine, 7.0 parts by weight of water and 6.9 parts by weight of ethanol were mixed and beaten using a high-pressure homogenizer at a stirring speed of 700 rpm. It was added dropwise to the acid-containing copolymer A aqueous dispersion. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Example 6 having an acid-containing copolymer content of 89.7% in the solid content was prepared. The coating agent of Example 6 uses one kind of acid-containing copolymer.

When the coating agent of Example 6 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. Regarding the ink foamability, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.54.

The coating agent of Example 6 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 6 for sanitary material of Example 6. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.25 g / m2, and the dry coating thickness was 0.5 μm.

48 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) having a solid content of 3% by weight, which was mechanically disintegrated after enzymatically treating wood pulp, as an amic acid-type amphoteric surfactant, N- 0.1 part by weight of sodium salt of lauroyl-N-methylglycine and 8.9 parts by weight of water are mixed, and the acid-containing copolymer A aqueous dispersion under a stirring speed of 700 rpm is subjected to beating treatment using a high-pressure homogenizer. Dropped into. After that, 0.3 parts by weight of a silicone defoamer, 0.3 parts by weight of wax, 0.4 parts by weight of a surface conditioner, and 5.0 parts by weight of glycerin were added under stirring to contain cellulose nanofibers in the total solid content. The coating agent of Example 7 having a rate of 4.2% and a content of the acid-containing copolymer in the total solid content of 72.7% was prepared. The coating agent of Example 7 uses one kind of acid-containing copolymer.

When the coating agent of Example 7 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. Regarding the ink foamability, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.22.

The coating agent of Example 7 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 500-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 7 for sanitary material of Example 7. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.24 g / m2, and the dry coating thickness was 0.5 μm.

20 parts by weight of the acid-containing copolymer B aqueous solution and 20 parts by weight of the acid-containing copolymer C aqueous dispersion were weighed in a stainless steel container having a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 22 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. The mixture was added dropwise to the acid-containing copolymers B and C mixed solution at a stirring speed of 700 rpm while performing a beating treatment using the above. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 6.1%, total. The coating agent of Example 8 having an acid-containing copolymer content of 88.3% in the solid content was prepared. The coating agent of Example 8 uses two kinds of acid-containing copolymers.

When the coating agent of Example 8 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. Regarding the ink foamability, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 7.22.

The coating agent of Example 8 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 250-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 8 for sanitary material of Example 8. Although some blurring and ink skipping were confirmed during coating, it did not affect mass productivity. The dry coating weight of the coating agent was 0.31 g / m2, and the dry coating thickness was 0.6 μm.

In a stainless steel container equipped with a stirrer, 10 parts by weight of the acid-containing copolymer C aqueous dispersion and 35 parts by weight of the acid-containing copolymer D aqueous dispersion were weighed and stirred at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 17 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. Was added dropwise to the acid-containing copolymers C and D mixed solution under a stirring speed of 700 rpm while performing a beating treatment using the above. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.5%, total. The coating agent of Example 9 having an acid-containing copolymer content of 89.5% in the solid content was prepared. The coating agent of Example 9 uses two kinds of acid-containing copolymers.

When the coating agent of Example 9 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 6.95.

The coating agent of Example 9 is applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product 9 for sanitary material of Example 9. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent was 0.24 g / m2, and the dry coating thickness was 0.5 μm.

The molded article 10 for sanitary material of Example 10 is obtained by using the coating agent of Example 1 to increase the coating weight, and the coating agent of Example 1 is 150 wires / in ceramic anilox roll, and the plate area is 50%. A breathable film (15 g / m2) is coated at a speed of 200 m / min with a flexographic printing machine having a striped printing plate, dried, and wound into a roll for the sanitary material of Example 10. Mold 10 was obtained. The dry coating weight of the coating agent was 0.60 g / m2, and the dry coating thickness was 1.2 μm. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good.

Next, Comparative Examples 1 to 12 using the acid-containing copolymers A to E will be described.

・ Comparative example 1
The molded product of Comparative Example 1 was coated on a breathable film (15 g / m2) by a flexographic printing machine using the coating agent of Example 2 so as to have a printing area of 75%, dried, and rolled. It is wound into a shape. In the molded product of Comparative Example 1, the dry coating weight of the coating agent was 0.38 g / m2, and the dry coating thickness was 0.4 μm.

・ Comparative example 2
The molded product of Comparative Example 2 was coated with a flexographic printing machine on a breathable film (15 g / m2) using the coating agent of Example 2 so as to have a printing area of 20%, dried, and rolled. It is wound into a shape. In the molded product of Comparative Example 2, the dry coating weight of the coating agent was 0.12 g / m2, and the dry coating thickness was 0.5 μm.

・ Comparative example 3
The acid-containing copolymer A aqueous dispersion was weighed in 48 parts by weight in a stainless steel container equipped with a stirrer, and the mixture was brought into a stirring state at a speed of 3500 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 14 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. Was added dropwise to the acid-containing copolymer A aqueous dispersion at a stirring speed of 3500 rpm while performing a beating treatment using the above. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Comparative Example 3 having an acid-containing copolymer content of 90.1% in the solid content was prepared. The coating agent of Comparative Example 3 was prepared by changing the stirring speed of the acid-containing copolymer A dispersion to 3500 rpm when preparing the coating agent of Example 1, and the other conditions were implemented. Same as Example 1.

When the coating agent of Comparative Example 3 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. However, the ink foamability immediately after the adjustment was remarkable, and the breathable film could not be coated. Therefore, it was not possible to form a molded product in which the coating agent of Comparative Example 3 was applied to the film.

・ Comparative example 4
25 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was brought into a stirring state at a speed of 700 rpm. In another stainless steel container, 55 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 19 parts by weight of water that were mechanically disintegrated after enzymatically treating wood pulp were mixed, and a high-pressure homogenizer was used. The mixture was added dropwise to the acid-containing copolymer A aqueous dispersion at a stirring speed of 700 rpm while performing a beating treatment using the above. After that, 0.3 parts by weight of the silicone defoamer, 0.3 parts by weight of the wax, and 0.4 parts by weight of the surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 13.0%. The coating agent of Comparative Example 4 having an acid-containing copolymer content of 79.1% in the solid content was prepared.

When the coating agent of Comparative Example 4 was filtered using a 200 μm filter in order to evaluate the suitability for inking, there was a level of filtration residue that could not be mass-produced. Further, regarding the ink foamability immediately after the adjustment, there was remarkable foaming, and the breathable film could not be coated. Therefore, it was not possible to form a molded product in which the coating agent of Comparative Example 4 was applied to the film.

・ Comparative example 5
80 parts by weight of the acid-containing copolymer A aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was brought into a stirring state at a speed of 700 rpm. In another stainless steel container, 15 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) and 4 parts by weight of water, which were mechanically disintegrated after enzymatically treating wood pulp, were mixed and a high-pressure homogenizer. The mixture was added dropwise to the acid-containing copolymer A aqueous dispersion at a stirring speed of 700 rpm while performing a beating treatment using the above. After that, 0.3 part by weight of the silicone defoamer, 0.3 part by weight of the wax, and 0.4 part by weight of the surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 1.3%. The coating agent of Comparative Example 5 having an acid-containing copolymer content of 95.7% in the solid content was prepared.

When the coating agent of Comparative Example 5 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent of Comparative Example 5 was measured using a B-type viscometer and found to be 2.04.

The coating agent of Comparative Example 5 was applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 700-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product of Comparative Example 5. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. In the molded product of Comparative Example 5, the dry coating weight of the coating agent was 0.23 g / m2, and the dry coating thickness was 0.4 μm.

-Comparative example 6
48 parts by weight of the acid-containing copolymer B aqueous solution was weighed in a stainless steel container having a stirrer, and the mixture was put into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Co., Ltd.) with a solid content of 3% by weight, which was mechanically disintegrated after enzymatically treating wood pulp, was N- as an amic acid type amphoteric surfactant. 0.1 part by weight of sodium salt of lauroyl-N-methylglycine and 13.9 parts by weight of water are mixed and added dropwise to an aqueous acid-containing copolymer B solution under a stirring speed of 700 rpm while beating with a high-pressure homogenizer. did. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Comparative Example 6 having an acid-containing copolymer content of 89.7% in the solid content was prepared. The coating agent of Comparative Example 6 is obtained by changing the acid-containing copolymer A aqueous dispersion of the coating agent of Example 2 to an acid-containing copolymer B aqueous solution, and other conditions are the same as those of Example 2.

When the coating agent of Comparative Example 6 was filtered using a 200 μm filter in order to evaluate the inking suitability, it could not be used as a coating agent due to significant aggregation and a large amount of filtration residue. Therefore, it was not possible to form a molded product in which the coating agent of Comparative Example 6 was applied to the film.

-Comparative example 7
48 parts by weight of the acid-containing copolymer C aqueous dispersion was weighed in a stainless steel container having a stirrer, and the mixture was brought into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) having a solid content of 3% by weight and 14.0 parts by weight of water, which were mechanically disintegrated after enzymatic treatment of wood pulp, were mixed. While beating with a high-pressure homogenizer, the mixture was added dropwise to the acid-containing copolymer C aqueous dispersion at a stirring speed of 700 rpm. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Comparative Example 7 having an acid-containing copolymer content of 90.1% in the solid content was prepared. The coating agent of Comparative Example 7 is obtained by changing the acid-containing copolymer A aqueous dispersion of the coating agent of Example 1 to the acid-containing copolymer C aqueous dispersion, and other conditions are the same as those of Example 1.

When the coating agent of Comparative Example 7 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent of Comparative Example 7 was measured using a B-type viscometer and found to be 7.2.

The coating agent of Comparative Example 7 was applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product of Comparative Example 7. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. The dry coating weight of the coating agent of Comparative Example 7 was 0.24 g / m2, and the dry coating thickness was 0.5 μm.

-Comparative example 8
48 parts by weight of the acid-containing copolymer D aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was brought into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) having a solid content of 3% by weight and 14.0 parts by weight of water, which were mechanically disintegrated after enzymatic treatment of wood pulp, were mixed. While beating with a high-pressure homogenizer, the mixture was added dropwise to the acid-containing copolymer D aqueous dispersion at a stirring speed of 700 rpm. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Comparative Example 8 having an acid-containing copolymer content of 90.1% in the solid content was prepared. The coating agent of Comparative Example 8 is obtained by changing the acid-containing copolymer A aqueous dispersion of the coating agent of Example 1 to an acid-containing copolymer D aqueous dispersion, and other conditions are the same as those of Example 1.

When the coating agent of Comparative Example 8 was filtered using a 200 μm filter in order to evaluate the inking suitability, some agglomerates were confirmed, but there was no problem in mass productivity. Regarding the ink foamability, it was confirmed that bubbles were generated on the liquid surface, but it did not affect the mass productivity. Next, when the thixotropic index value (TI value) of the coating agent of Comparative Example 8 was measured using a B-type viscometer, it was 6.42.

The coating agent of Comparative Example 8 was applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 400-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product of Comparative Example 8. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. In the molded product of Comparative Example 8, the dry coating weight of the coating agent was 0.28 g / m2, and the dry coating thickness was 0.5 μm.

-Comparative example 9
48 parts by weight of the acid-containing copolymer E aqueous dispersion was weighed in a stainless steel container equipped with a stirrer, and the mixture was brought into a stirring state at a speed of 700 rpm. In another stainless steel container, 37 parts by weight of a cellulose nanofiber dispersion (manufactured by Daio Paper Corporation) having a solid content of 3% by weight and 14.0 parts by weight of water, which were mechanically disintegrated after enzymatic treatment of wood pulp, were mixed. While beating with a high-pressure homogenizer, the mixture was added dropwise to the acid-containing copolymer E aqueous dispersion at a stirring speed of 700 rpm. After that, 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and 0.4 parts by weight of a surface conditioner were added under stirring, and the cellulose nanofiber content in the total solid content was 5.2%, total. The coating agent of Comparative Example 9 having an acid-containing copolymer content of 90.1% in the solid content was prepared. The coating agent of Comparative Example 9 is obtained by changing the acid-containing copolymer A aqueous dispersion of the coating agent of Example 1 to an acid-containing copolymer E aqueous dispersion, and other conditions are the same as those of Example 1.

When the coating agent of Comparative Example 9 was filtered using a 200 μm filter in order to evaluate the suitability for inking, there was a level of filtration residue that could not be mass-produced. Therefore, it was not possible to form a molded product in which the coating agent of Comparative Example 9 was applied to the film.

-Comparative example 10
72 parts by weight of the acid-containing copolymer A aqueous dispersion and 27 parts by weight of water are mixed in a stainless steel container equipped with a stirrer to prepare 0.3 parts by weight of a silicon-based defoamer, 0.3 parts by weight of wax, and surface adjustment. 0.4 parts by weight of the agent was added to prepare a coating agent of Comparative Example 10 containing 96.6% of the acid-containing copolymer in the total solid content, which did not contain cellulose nanofibers.

When the coating agent of Comparative Example 10 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent of Comparative Example 10 was measured using a B-type viscometer and found to be 1.04.

The coating agent of Comparative Example 10 was applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 600-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product of Comparative Example 10. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. In the molded product of Comparative Example 10, the dry coating weight of the coating agent was 0.24 g / m2, and the dry coating thickness was 0.5 μm.

-Comparative example 11
In a stainless steel container equipped with a stirrer, 15 parts by weight of the acid-containing copolymer B aqueous solution, 15 parts by weight of the acid-containing copolymer C aqueous dispersion, and 50 parts by weight of the acid-containing copolymer D aqueous dispersion are weighed, and 9 parts by weight of water is used. Parts were mixed, 0.3 parts by weight of silicon-based defoamer, 0.3 parts by weight of wax, 0.4 parts by weight of surface conditioner, and 10 parts by weight of glycerin were added, and the acid-containing copolymer was contained in the total solid content. The coating agent of Comparative Example 11 having a rate of 74.4% was prepared.

When the coating agent of Comparative Example 11 was filtered using a 200 μm filter in order to evaluate the inking suitability, no agglomerates were confirmed. In addition, almost no bubbles were observed in the ink foamability immediately after the adjustment. Next, the thixotropic index value (TI value) of the coating agent was measured using a B-type viscometer and found to be 1.05.

The coating agent of Comparative Example 11 was applied to a breathable film (15 g / m2) at a speed of 200 m / min by a flexographic printing machine having a 900-line / in ceramic anilox roll and a striped printing plate having a plate area of 50%. Then, it was dried and wound into a roll to obtain a molded product of Comparative Example 11. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good. In the molded product of Comparative Example 11, the dry coating weight of the coating agent was 0.22 g / m2, and the dry coating thickness was 0.4 μm.

-Comparative example 12
The molded product of Comparative Example 12 was obtained by using the coating agent of Example 1 to reduce the coating weight, and the coating agent of Example 1 was a striped product of 1000 wires / in ceramic anilox roll and a plate area of 50%. A breathable film (15 g / m2) was coated at a speed of 200 m / min with a flexographic printing machine having a printing plate, dried, and wound into a roll to obtain a molded product 12 of Comparative Example 12. .. The dry coating weight of the coating agent of Comparative Example 12 was 0.10 g / m2, and the dry coating thickness was 0.05 μm. During coating, printing defects such as variation in coating amount, blurring, poor drying, and ink skipping did not occur, and the printability was good.

The following tests and evaluations were carried out for Examples 1 to 10 and Comparative Examples 1 to 12.
(1) Test and evaluation of coating agent ・ Ink suitability: Ink (coating agent) is filtered using a 200 μ filter, and the amount of residue remaining on the filter surface is evaluated in the following four stages.
◎ ・・・ No filtration residue at all ○ ・・・ There is some filtration residue, but it does not affect mass productivity △ ・・・ There is a level of filtration residue that cannot be mass-produced.
×: There is significant aggregation, and there is a large amount of filtration residue.
-Ink foamability: The foamability immediately after inking is visually evaluated in the following four stages.
◎ ・・・ No bubbles on the ink surface ○ ・・・ Some bubbles remain on the ink surface, but it does not affect mass productivity △ ・・・ There is a level of foaming that cannot be mass-produced × ・・-Remarkable foaming-Coating suitability: The degree of occurrence of printing defects such as variation in coating amount, blurring, drying defects, and ink skipping during printing is evaluated in the following four stages.
◎ ・・・ No printing defects occur ○ ・・・ Minor printing defects occur, but they do not affect mass productivity △ ・・・ Printing defects occur at a level that cannot be mass-produced × ・・-Printing is not possible.

(2) Test and evaluation of dry film formed on the surface of the molded product ・ Water resistance: After immersing the molded product in water for 30 minutes, a fir test was conducted 10 times to visually determine the degree of ink dropout, and the following Evaluate on a 4-point scale.
◎ ・・・ No ink dropout ○ ・・・ Slight ink dropout, but practically no problem level △ ・・・ Practical problematic level of ink dropout × ・・・ Significant Ink may fall off ・ Blocking property: The peeling resistance when peeling the printed matter wound in a roll shape and the degree of ink adhesion to the back surface of the film are evaluated in the following four stages.
◎ ・・・ No adhesion at all.
○ ・・・ There is some resistance when peeling the film, but there is no problem in practical use △ ・・・ There is no ink adhesion to the back surface of the film, but there is strong resistance when peeling × ・・・ Back side of the film There is ink adhesion to the ink. ・ Fir property: A fir test is carried out 10 times on the printed matter, the degree of ink dropout is visually judged, and the evaluation is made in the following four stages.
◎ ・・・ No ink drop ○ ・・・ Slight ink drop, but practically no problem level △ ・・・ Practically problematic level of ink drop × ・・・ Significant ink drop There is shedding ・ Moisture absorption: 20 sheets of 100 mm square filter paper are stacked on a horizontal test table, and a molded body with a dry film formed is placed and fixed on the molded body, and artificial urine composed of urea or the like is placed on the molded body. 70 cc is injected, and after the artificial urine disappears from the surface, a weight with a bottom area of 100 cm2 and a weight of 3 kg is placed on the surface of the injection part and held for 15 minutes, then the filter paper is taken out and the weight is measured before the artificial urine is injected. The weight change of the filter paper obtained by subtracting the weight of the filter paper is measured four times, and the average value is taken as the wetness of the molded product, and the evaluation is made in four stages of ⊚, ◯, Δ, and ×.
-Humidity permeability: Based on JIS Z 0208 "Permeability test method for moisture-proof packaging material (cup method)", moisture permeability is tested and evaluated on a scale of ◎, ○, Δ, and ×.
In the evaluation of the above tests, ◎ and 〇 are passed, and △ and × are rejected.

The results of the tests and evaluations of Examples 1 to 10 are shown in Table 1, and the results of the tests and evaluations of Comparative Examples 1 to 12 are shown in Table 2.

With reference to Examples 1 to 10, it can be seen that the coating agent of the present invention sufficiently satisfies practicality and has no problem in coatability. It can also be seen that the dry film of the molded article for sanitary materials of the present invention also sufficiently satisfies the practicality. In addition, it was found that both hygroscopicity and moisture permeability are compatible.

With reference to the results of Comparative Examples 1 and 2, there is no problem in the test and evaluation of the coating agent and the molded product coated with the coating agent, but as described in Remark 1, if the coated area is too large. It can be seen that the moisture permeability is insufficient (Comparative Example 1), and if the coating area is too small, the hygroscopicity is insufficient (Comparative Example 2), and the molded product for sanitary materials of the present invention is not suitable.

Referring to the results of Comparative Examples 3, 4, 6 and 9, when the stirring speed was high (3500 rpm) and the TI value was high (20.4) (Comparative Example 3), the proportion of cellulose nanofibers was high (55 parts by weight). ), When the TI value is high (12.3) (Comparative Example 4), when the acid value of the acid-containing copolymer is high (286 mgKOH / g) (Comparative Example 6), when the acid value of the acid-containing copolymer is low (43 mgKOH /). It can be seen that g) (Comparative Example 9) does not satisfy the practicality as a coating agent.

With reference to the result of Comparative Example 5, when the proportion of the cellulose nanofibers is low, there is no problem in the test and evaluation of the coating agent and the molded product coated with the coating agent, but as described in Remark 1, It can be seen that the problem of insufficient hygroscopicity arises and the molded product for sanitary materials of the present invention is not suitable.

With reference to the results of Comparative Examples 7 and 8, when the glass transition point is low (Tg = -6 ° C) (Comparative Example 7) and the glass transition point is high (Tg = 72 ° C) (Comparative Example 8), the coating is applied. Although it satisfies the practicality as an agent, it can be seen that there is a problem in the practicality because all the conditions cannot be satisfied with respect to the dry film on the surface of the molded product.

With reference to the results of Comparative Example 10, when the cellulose nanofibers are not contained, there is no problem in the test and evaluation of the coating agent and the molded product coated with the coating agent, but as described in Remark 1, It can be seen that the problem of insufficient hygroscopicity arises and the molded product for sanitary materials of the present invention is not suitable.

With reference to the results of Comparative Example 11, when the cellulose nanofibers are not contained and a large amount of glycerin is contained, there is no problem in practicality as a coating agent, but there are problems in water resistance and blocking property as a dry film. It can be seen that it is not suitable as a molded product for sanitary materials of the present invention.

With reference to the results of Comparative Example 12, it can be seen that when the dry coating weight of the coating agent is small, the thickness of the dry coating becomes thin and the hygroscopicity is insufficient, which makes it unsuitable for the molded article for sanitary materials of the present invention. ..

From the above test results, it can be seen that the coating agent of the present invention has sufficient coatability in practical use and can form a dry film having hygroscopicity. With such a coating agent, it becomes possible to form a dry film having hygroscopicity on a molded product for sanitary materials such as disposable diapers, and it becomes possible to add hygroscopicity without impairing moisture permeability. By using the molded article for sanitary material of the present invention as a disposable diaper, it is possible to solve the problem that clothes and the like are moistened by the moisture that has permeated the disposable diaper.

1 Molded body for sanitary materials 2 Dry film 3 Water permeable waterproof film

Claims

A coating agent that forms a hygroscopic dry film.
Contains cellulose nanofibers, acid-containing copolymers, and solvents
The cellulose nanofibers and the acid-containing copolymer are dispersed by the solvent.
The acid-containing copolymer is formed from at least one (meth) acrylate-based monomer and at least one vinyl-based monomer.
The acid-containing copolymer is a coating agent having an acid value of 50 to 150 mgKOH / g and a glass transition point of 20 to 50 ° C., which is one kind of acid-containing copolymer.
A coating agent that forms a hygroscopic dry film.
Contains cellulose nanofibers, acid-containing copolymers, and solvents
The cellulose nanofibers are dispersed in the solvent and the acid-containing copolymer is dissolved or dispersed in the solvent.
The acid-containing copolymer is formed from at least one (meth) acrylate-based monomer and at least one vinyl-based monomer.
The acid-containing copolymer is a coating agent characterized by being at least two kinds of acid-containing copolymers having an acid value of 50 to 300 mgKOH / g and a glass transition point of −10 to 150 ° C.
The coating agent according to claim 1 or 2, wherein the cellulose nanofibers are contained in a proportion of 2 to 10% by weight, and the acid-containing copolymer is contained in a proportion of 95 to 70% by weight.
The coating agent according to any one of claims 1 to 3, wherein the thixotropic index value (TI value) is 10 or less.
A molded product for sanitary materials in which a dry film having hygroscopicity is formed on a part of one side of a moisture-permeable waterproof film.
A molded article for a sanitary material, wherein the dry film is formed by the coating agent according to any one of claims 1 to 4.
The molded article for sanitary materials according to claim 5, wherein the dry film is formed at a ratio of 30 to 70% of the flat area of one side of the moisture-permeable waterproof film.
The molded article for sanitary materials according to claim 5 or 6, which is characterized by being used for disposable diapers.
The method for producing a coating agent according to any one of claims 1 to 4.
Prepare a dispersion of the cellulose nanofibers and prepare
The acid-containing copolymer is stirred at a rate of 50-1000 rpm and
A method for producing a coating agent, which comprises adding a dispersion of cellulose nanofibers to the acid-containing copolymer in a stirred state while performing a beating treatment.
The claim is characterized in that after adding an amino acid-type amphoteric surfactant or a polyvinylacetamide-based compound to the dispersion liquid of the cellulose nanofibers, the dispersion liquid of the cellulose nanofibers is added to the acid-containing copolymer in a stirred state. 8. The method for producing a coating agent according to 8.