JP2008087854A - Carton for thin paper and thin paper box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carton for thin paper which is excellent in printability and processing aptitude, and in addition, which also has an action decomposing a harmful substance by application of a light and which has restrained discoloration. <P>SOLUTION: The carton for the thin paper using coated paper which is provided with a coated layer having a pigment and an adhesive as principal components on base paper contains titanium oxide with an average particle diameter of a secondary particle of 300-2,000 nm in an amount of 1-30 pts.wt. per 100 pts.wt. of the pigment in the coated layer, and the thin paper is stored in the carton for the thin paper in which this coated paper has been printed, stamped out and made into case. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thin paper carton having good processability and an excellent air cleaning effect, and a thin paper box containing thin paper in a thin paper carton.

  With increasing interest in the living environment, the demand for removal of harmful substances such as bad odors in daily life is increasing, and titanium oxide is attracting attention. Titanium oxide has traditionally been used as a pigment with excellent opacity and whiteness for papermaking, but fine titanium oxide uses light energy to cause a redox reaction and decompose various harmful substances in the air. In order to take advantage of this phenomenon, development is being carried out so as to be carried on paper, and cartons for thin paper having photocatalytic activity using these papers have been demanded.

  As the development of photocatalyst paper, for example, photocatalyst paper in which a water-soluble polymer and a substance having a photocatalytic action such as titanium oxide are embedded in paper is disclosed (see Patent Document 1), but the photocatalytic substance is exposed to light. Therefore, the method having a photocatalytic substance inside the paper layer is not efficient and the effect is not sufficient. In addition, the print quality when color printing such as ink fillability, printing glossiness, and sharpness of printed matter is not sufficient. In addition, a printing sheet is disclosed in which a titanium oxide fine powder is bonded to an inorganic binder such as silica sol, and a coating material in which the surroundings are bonded with an organic adhesive is applied (see Patent Documents 2 and 3). However, when a titanium oxide / silica sol mixed paint is applied, the particle diameter of titanium oxide and silica sol is small, the viscosity of the paint is extremely increased, and the coating suitability is poor. In addition, the coating property by the paint is insufficient, and there is a problem that the printing quality such as printing glossiness, printing surface feeling and surface strength is inferior. Further, as printing paper, in an environment exposed to ultraviolet rays such as sunlight, there is a problem of fading due to a decrease in whiteness, and there is a problem in storage stability.

In addition, when coated paper with photocatalytic ability is used for thin paper carton, there is also a problem that processing suitability is inferior, it has good printability, fading property, processing suitability, and the action of decomposing harmful substances when exposed to light There has been a demand for a thin paper carton and a thin paper box.
Japanese Patent Laid-Open No. 10-226983 JP 2000-129595 A Japanese Patent Laid-Open No. 11-117196

  In view of such circumstances, the object of the present invention is to provide a thin paper carton and a thin paper box which have excellent printability and processability, and also have an action of decomposing harmful substances when exposed to light, and which suppresses fading. To provide a body.

  In order to achieve the above-mentioned object, the present inventors have conducted intensive research.As a result, the printing quality is good, and there is an action of decomposing harmful substances and odor components when exposed to light, and it is possible to suppress fading. The inventors have found that a thin paper carton having excellent processability can be obtained, and have completed the present invention.

  The invention according to claim 1 is a thin paper carton using a coated paper in which a base paper is provided with a coating layer mainly composed of a pigment and an adhesive. The average particle diameter of secondary particles in the coating layer is 1 to 30 parts by weight of titanium oxide having a wavelength of 300 nm to 2000 nm is contained per 100 parts by weight of the pigment.

  Invention of Claim 2 mix | blends 5-40 weight part organic adhesive with respect to 100 weight part of pigments in the said coating layer of Claim 1, and 50-90 weight% of organic adhesives Is a copolymer latex.

  Invention of Claim 3 uses the copolymer latex whose glass transition temperature is -20-40 degreeC as an adhesive agent in the said coating layer of Claim 1 or 2, It is characterized by the above-mentioned. To do.

  The invention according to claim 4 is characterized in that the primary particle diameter of the titanium oxide according to any one of claims 1 to 3 is 5 to 100 nm.

  The invention according to claim 5 is characterized in that the cast coated paper according to any one of claims 1 to 4 is used to cast finish the wet coated layer.

  The invention according to claim 6 is characterized in that the coated paper according to claims 1 to 5 is subjected to printing, punching, and box making.

  The invention according to claim 7 is a thin paper box, wherein the thin paper is stored in the thin paper carton according to claim 6.

  In the invention according to claim 1, in the carton for thin paper using the coated paper in which the base paper is provided with a coating layer mainly composed of a pigment and an adhesive, the average particle diameter of the secondary particles is in the coating layer. By containing 1 to 30 parts by weight of titanium oxide of 300 nm to 2000 nm per 100 parts by weight of pigment, the printing quality is good, and it also has the action of decomposing harmful substances and odor components when exposed to light, and suppresses fading. A thin paper carton having excellent processability can be obtained.

  Invention of Claim 2 mix | blends 5-40 weight part organic adhesive with respect to 100 weight part of pigments in the said coating layer of Claim 1, and 50-90 weight% of organic adhesives Since it is a copolymer latex, it is possible to obtain a good balance between printing quality such as good coating suitability, workability, excellent printing glossiness, printing surface feel, and surface strength, and photocatalytic effect.

  Since invention of Claim 3 uses the copolymer latex whose glass transition temperature is -20-40 degreeC as an adhesive agent in the said coating layer of Claim 1 or 2, it is for printing. It is possible to obtain a sufficient balance between the sufficient surface strength that can be tolerated, the suitability for carton processing, and the photocatalytic effect.

  Since the primary particle diameter of the titanium oxide according to any one of claims 1 to 3 is 5 to 100 nm, the print quality and printing workability and the photocatalytic effect are obtained in a more balanced manner. It becomes possible.

  Since the invention according to claim 5 uses the cast coated paper that casts the wet coated layer according to any one of claims 1 to 4, high printability and photocatalytic effect can be obtained in a more balanced manner. It becomes possible.

  The invention according to claim 6 is a thin paper carton having good print quality, deodorizing and air purifying effects since the coated paper according to claims 1 to 5 is printed, stamped and boxed. Can be obtained.

  The invention according to claim 7 is a thin paper box, and the thin paper carton according to claim 6 contains the thin paper, so that it is widely used for household, industrial field and business use. A thin paper box having a cleaning effect can be easily obtained industrially at low cost.

  Embodiments of the present invention will be described below.

  The coated paper provided with a coating layer mainly composed of a pigment and an adhesive on the base paper used for the thin paper carton according to the present invention is oxidized with an average particle diameter of secondary particles in the coating layer of 300 nm to 2000 nm. 1-30 parts by weight of titanium is contained per 100 parts by weight of pigment.

  Titanium oxide itself blended as a part of the pigment in the coating liquid for forming the coating layer has a photocatalytic performance that imparts an air cleaning effect to the coated paper regardless of the particle diameter. Titanium oxide whose average particle size is 300 nm to 2000 nm is used at a specific blending ratio. The average particle diameter of the secondary particles of titanium oxide is not particularly limited as long as it is in the range of 300 nm to 2000 nm, but is preferably 500 to 1500 nm, and more preferably 700 to 1300 nm.

  If the average particle diameter of the secondary particles of titanium oxide is less than 300 nm, the dispersibility of the titanium oxide slurry is lowered and the viscosity of the paint is extremely high, so that the productivity is lowered, and further, the print quality due to the lack of titanium oxide, Printing workability is reduced. On the other hand, when the average particle diameter of the secondary particles exceeds 2000 nm, the smoothness of the coated paper is lowered and the printing quality is lowered.

  The primary particle diameter of titanium oxide is preferably 5 to 100 nm, more preferably 10 to 50 nm. When the primary particle size is less than 5 nm, the dispersibility of the titanium oxide slurry and the fluidity of the coating are liable to deteriorate, and the printing quality and printing workability tend to be inferior. Moreover, since a specific surface area will become small when it exceeds 100 nm, it exists in the tendency for photocatalytic performance to not be enough.

  As described above, in the present invention, it is important to use titanium oxide having a secondary particle average particle size of 300 nm to 2000 nm at a specific blending ratio.

  Fine titanium oxide can have the ability to decompose harmful substances in the air when exposed to light. The compounding ratio of titanium oxide is 1 to 30 parts by weight, preferably 5 to 25 parts by weight, more preferably 5 to 20 parts by weight, out of 100 parts by weight of the pigment. When the compounding ratio of titanium oxide is less than 1 part by weight, the amount of the photocatalyst is too small to obtain a sufficient air cleaning effect.

  In the present invention, it is important to use fine titanium oxide having a high photocatalytic effect. However, fine titanium oxide has very poor fluidity, and the slurry concentration is extremely low when slurried for use in paints. Become. Therefore, when blended in an amount exceeding 30 parts by weight, an air cleaning effect can be obtained, but the coating concentration is greatly reduced, so that it becomes difficult to apply a coating amount of a certain value or more, and a general coating When compared with the amount of coating applied with paper, it is inferior in printing quality such as surface strength and choking resistance. The choking resistance suitability indicates resistance to powder falling due to photodegradation and deterioration of the coating layer surface and the base paper layer after light irradiation.

  In addition to titanium oxide, titanium oxide in the present invention is manufactured from hydrous titanium oxide, hydrated titanium oxide, metatitanic acid, orthotitanic acid, and all titanium oxides or hydroxides called titanium hydroxide. Can do.

  In addition to an ultraviolet light responsive photocatalyst generally used as a photocatalyst, a visible light responsive photocatalyst exhibiting a photocatalytic effect in response to light in the visible light region can also be used.

The titanium oxide used in the present invention preferably has a specific surface area of 10 to 350 m ² / g. In addition, since the titanium oxide of the present invention is mixed with silica sol or alumina sol in the titanium oxide, the silica sol or alumina sol having an inorganic adhesion function is coated around the fine titanium oxide, and therefore, fading due to degradation of the paper due to the decomposition reaction of the photocatalyst. Can be further improved, and the deterioration of the print quality due to the decomposition of the ink components can be further suppressed. The mixing ratio of the titanium oxide and the inorganic adhesive of silica sol or alumina sol is about 5: 1 to 1: 5, preferably 2: 1 to 1: 2, in terms of polymerization ratio. Moreover, it is preferable to use a silica sol from the point of light transmittance. When preparing the coating solution, in order to efficiently coat the surroundings of fine titanium oxide, a colloidal solution of titanium oxide and silica or alumina is mixed at a certain ratio, and after stirring for a certain time, other pigments and auxiliaries are added. Is preferable. In the present invention, it is also possible to mix a mixture of silica sol and alumina sol inorganic adhesives with titanium oxide.

  In addition, when cast coated paper is used as coated paper, a high-quality white paper carton having high glossiness is obtained, but the surface of cast coated paper is rubbed during carton processing. The problem of scratching may occur. In this case, it is preferable to contain 5 parts by weight or more of the above-mentioned silica sol with respect to 100 parts by weight, and more preferably 5 to 50 parts by weight improves the scratch of the thin paper carton. This is important for improving the cosmetic properties of the thin paper box as the final product. Also, in order to improve the runnability without causing troubles such as carton base paper or carton printing or processing, the mixing ratio of titanium oxide and silica sol or alumina sol is 2 in polymerization ratio. : 1 to 1: 2 is preferable, and 2: 1 to 1: 1.5 is more preferable.

  In the present invention, other pigments provided in the coating layer include kaolin, clay, delaminated clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, which are conventionally used in coated paper production. Inorganic pigments such as calcium sulfate, zinc oxide, silicic acid, silicate, colloidal silica, and satin white, and organic pigments such as plastic pigment can be selected and used as necessary. In the present invention, when used for cast coated paper having a high white paper glossiness, kaolin such as engineered kaolin is preferably used from the viewpoint of photocatalytic effect and carton processing suitability improvement, and the blending amount is 100 weight of pigment. The amount is preferably 10 parts by weight or more, more preferably 40 parts by weight or more with respect to parts.

  In the present invention, an organic adhesive is used as an adhesive that is a main component of the coating layer together with the pigment. 40 parts by weight is preferable, more preferably 8 to 40 parts by weight, still more preferably 8 to 30 parts by weight, and particularly preferably 10 to 20 parts by weight. When the organic adhesive is less than 5 parts by weight, sufficient surface strength cannot be obtained, and the carton processing suitability is inferior. On the other hand, when the amount exceeds 40 parts by weight, the coating concentration decreases, it becomes difficult to control the coating amount, the drying load increases, the coating speed decreases, and the titanium oxide is an adhesive. It is not preferable because it has a disadvantage that the air cleaning effect is reduced. From the viewpoint of the air cleaning effect, it is preferable that the number of blended parts of the organic adhesive is small.

  Various adhesives such as styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, and vinyl acetate / butyl acrylate, which have been conventionally used for coated paper, are used as the adhesive of the present invention. Polymer latex, synthetic adhesives such as polyvinyl alcohol, maleic anhydride copolymer, acrylic acid / methyl methacrylate copolymer, casein, soybean protein, synthetic protein proteins, oxidized starch, positive starch, urea phosphorus One or more kinds of organic adhesives such as acid esterified starch, etherified starch such as hydroxyethyl etherified starch, starch such as dextrin, cellulose derivative adhesive such as carboxyethyl cellulose, hydroxyethyl cellulose or hydroxymethyl cellulose are appropriately selected. used.

  In order to make the surface strength, the air cleaning effect and the carton processing suitability good, the copolymer latex is preferably 50% by weight or more, more preferably 60% by weight or more in the organic adhesive as the organic adhesive. In the production of coated paper for printing, latex and starch are often used in combination.

  The UV transmittance of these simple substances is almost the same when compared at the same coating amount. On the other hand, since starch has poor adhesive strength compared to latex, starch can be obtained compared to latex to obtain the same surface strength. It is necessary to mix a lot. When the amount of latex in the organic adhesive is less than 50%, the photocatalytic effect tends to decrease, and the carton processing suitability is also poor.

  The copolymer latex used is preferably a copolymer latex having a glass transition temperature of -20 to 40 ° C, more preferably -20 to 30 ° C, and still more preferably -10 to 30 ° C. is there. When the glass transition temperature exceeds 40 ° C., it is difficult to obtain sufficient surface strength that can withstand printing and suitability for carton processing. Further, when the glass transition temperature is less than −20 ° C., the photocatalytic effect tends to be insufficient, and the operability tends to decrease due to stickiness to the roll. For a copolymer latex such as a core-shell type having different glass transition temperatures in the particles, the glass transition temperature of the shell layer (surface layer) is preferably within the above temperature range, and the core layer (inner layer) It is preferable that the glass transition temperature of is lower than that of the shell layer (surface layer). The particle diameter of the copolymer latex is preferably 50 to 250 nm from the viewpoint of printing quality and surface strength. The water-soluble polymer adhesive such as starch is preferably 10 parts by weight or less.

  In addition to the above pigments and adhesives, the coating layer contains sodium chloride, ammonium chloride, zinc chloride, magnesium chloride, sodium sulfate, potassium sulfate, ammonium sulfate, zinc sulfate, magnesium sulfate, ammonium nitrate, and sodium monophosphate. , Ammonium phosphate, calcium phosphate, sodium polyphosphate, sodium hexametaphosphate, sodium formate, ammonium formate, sodium acetate, potassium acetate, sodium monochlorophosphate, sodium malonate, sodium tartrate, potassium tartrate, sodium citrate, potassium citrate, lactic acid Ammonium salts and metal salts of inorganic and organic acids such as sodium, sodium gluconate, sodium adipate, sodium dioctylsulfosuccinate, methylamine, diethanolamine, diethylene Triamine, can be appropriately used various additives such as diisopropylamine.

  In addition, if necessary as a auxiliaries, it is possible to use ordinary coatings such as dispersants, thickeners, water retention agents, antifoaming agents, colorants, mold release agents, flow modifiers, water resistance agents, preservatives, and printability improvers Various auxiliaries blended in the coating composition for industrial paper are appropriately used.

  Ordinary pulp, filler and the like are blended in the base paper for coating of the present invention. In the present invention, the type of pulp blended into the base paper is not particularly limited. For example, hardwood kraft pulp (hereinafter referred to as LBKP), softwood kraft pulp (hereinafter referred to as NBKP), thermomechanical pulp, groundwood pulp, waste paper pulp, etc. are used. When used in a large amount, it deteriorates and discolors when exposed to light. Therefore, the mechanical pulp preferably has a content of 60% by weight or less of the total pulp, and the chemical pulp is most preferably 100% from the viewpoint of print quality.

  In addition, as fillers to be mixed in the base paper for coating, heavy calcium carbonate, light calcium carbonate, kaolin, clay, talc, amorphous silicate, amorphous silica, light calcium carbonate-silica composite, hydrated silicic acid, white Known fillers such as carbon, titanium oxide, and synthetic resin fillers can be used. The compounding quantity of a filler is about 1-30 weight% with respect to a pulp weight, Preferably it is 3-20 weight%.

  These fillers may be used alone or in combination of two or more for the purpose of adjusting papermaking suitability and strength characteristics of the paper stock slurry. Also, if necessary, chemicals usually used in the papermaking process, such as paper strength enhancers, sizing agents, antifoaming agents, colorants, softening agents, bulking agents (low density agents), etc. As long as the effect is not hindered, it can be added to the paper to make paper.

  The paper making method of the base paper for coated paper is not particularly limited, and the base paper made by acid paper making, neutral paper making, alkaline paper making method using a long net machine including a top wire, a round net machine, etc. Any of them may be used, and of course, a medium base paper containing mechanical pulp can be used.

  Furthermore, for the purpose of improving the surface strength and sizing properties, a surface treatment agent containing a water-soluble polymer as a main component may be applied to the base paper. As the water-soluble polymer, those usually used as surface treating agents such as oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, etc. can be used alone or a mixture thereof. .

In addition to the water-soluble polymer, a paper strength enhancer for the purpose of water resistance and surface strength improvement and an external sizing agent for the purpose of imparting sizing can be added to the surface treatment agent. The surface treatment agent can be applied by a coating machine such as a 2-roll size press coater, a gate roll coater, a blade metering size press coater, a rod metalling size press coater, and a film transfer type roll coater such as a shim sizer. As the coating base paper, those having a basis weight of about 230 to 600 g / m ² used for general coated paper and coated paperboard are used, and more preferably 230 to 500 g / m ² .

As a method of coating the coating liquid adjusted on the coating base paper, using a blade coater, bar coater, roll coater, air knife coater, reverse roll coater, curtain coater, size press coater, gate roll coater, etc. Or two or more layers are coated on one or both sides of the base paper. Scope of coverage of the present invention is not particularly limited, print quality, photocatalytic effect, in order to better balance the coatability, preferably per side 2 g / m ² or more 40 g / m ² or less, more preferably at 5 g / ^{m 2} or more 35 g / ^{m 2} or less, further preferably 10 g / ^{m 2} or more 30 g / ^{m 2} or less.

  In the present invention, when photocatalytic titanium oxide is blended in the coating layer, titanium oxide distributed in the upper layer of the coating layer is effective for the photocatalytic effect. Therefore, in the present invention, two or more coating layers are provided, the outermost layer is provided with a coating layer containing titanium oxide as defined above, and the inner layer is provided with a prepared coating layer different from the outermost layer. Thus, a coated paper for printing having a photocatalytic effect and further improved in printing quality, surface strength and the like can be obtained.

In that case, the coating containing the photocatalytic titanium oxide applied to the outermost layer is preferably 1 g / m ² or more and 20 g / m ² or less, more preferably 3 g / m ² or more and 15 g / m ² or less, and still more preferably. Is 5 g / m ² or more and 15 g / m ² or less.

  As a method for drying the wet coating layer, for example, usual methods such as a steam heater, a gas heater, an infrared heater, an electric heater, a hot air heater, a microwave, and a cylinder dryer are used.

  After drying, if necessary, smoothness can be imparted by finishing processes such as super calendering and high-temperature soft calendering, which are post-processing, and any calendering treatment can be performed as long as coated paper of the desired quality is obtained. Alternatively, uncalendar processing may be used. However, due to the calendering process, the coating layer has a dense structure and the smoothness becomes higher, so the surface area with air is reduced, so the contact probability between the photocatalyst compounded in the coating layer and harmful components in the air. Decreases, and the air cleaning effect decreases. Therefore, in the present invention, weak calendar processing with a linear pressure of 150 kN / m or less is preferable, and uncalender processing is more preferable.

  In the present invention, it is preferable that the PPS roughness is in the range of 0.5 to 5.0 μm in order to have good print quality and a photocatalytic function. When the PPS roughness exceeds 5.0 μm and the numerical value is high, the smoothness is inferior, so that the ink inking property at the time of printing is deteriorated and the printing surface feeling and the printing gloss are inferior. On the other hand, when the PPS roughness value is low, the smoothness is high, but the coating layer has a dense structure, and the surface area with air is small, so the contact between the photocatalyst compounded in the coating layer and harmful components in the air The probability decreases and the air cleaning effect decreases. The PPS roughness is preferably 1.0 to 4.0 μm, more preferably 2.0 to 4.0 μm. The PPS roughness can be prepared according to calendar processing conditions, pulp blending, paint blending, coating amount, and the like.

  In the present invention, the base paper is provided with a coating layer mainly composed of a pigment and an adhesive, and the coating layer in a wet state is pressed onto a heated mirror drum (cast drum) surface and dried to finish. When obtaining coated paper, the following method is used.

For the base paper for cast coating, as described above, the base paper made by the normal paper making method can be used, and the surface treatment with a water-soluble polymer as the main component is used for the purpose of improving the surface strength and size. An agent may be applied. In addition to the application of the surface treatment agent, the base paper coated with a coating liquid containing a pigment and an adhesive used for general coated paper using the coating machine, or the surface treatment agent is applied and dried. After that, a base paper coated with a blade coater, a roll coater, an air knife coater or the like can also be used as a base paper for the coated paper. The coating amount in that case is preferably about 1 to 40 g / m ² in terms of dry weight per side.

  Moreover, it is possible to apply one side and both sides according to a use. As a method for drying the wet coating layer, for example, various types of dryers such as the above heating cylinder, heated hot air air dryer, gas heater dryer, electric heater dryer, infrared heater dryer and the like are used alone or in combination. The degree of drying of the coated paper varies depending on the type of base paper, the type of coating composition, etc., but is generally in the range of about 1 to 10% as paper moisture, and preferably dried in the range of about 2 to 7%. . Further, if necessary, the precoated base paper can be subjected to a smoothing process such as a super calendar or a soft calendar in advance.

As a method for applying the cast coating composition prepared on the base paper, a two-roll size press coater, a gate roll coater, a blade metering size press coater and a rod metering size press coater, Simsizer, JF sizer, Film transfer type roll coater such as reverse roll coater, flooded nip / blade coater, jet fountain / blade coater, short dwell time application type coater, rod using grooved rod, plain rod, etc. instead of blade It can be applied by a known coater such as a metering coater, an air knife coater, a curtain coater or a die coater, and the coating amount is preferably 4 to 40 g / m ² per side of the base paper. Properly in 5~35g / ^{m 2,} more preferably from 10 to 30 g / ^{m 2.}

  After coating the cast layer, cast finish. Cast finishing methods include the direct method of casting in a wet state, the solidification method of solidifying and casting a wet coating layer, and once drying the wet coating layer and applying with a rewetting liquid. There are rewetting methods in which the work layer is rewet and cast finish, and the rewetting method and the coagulation method are preferred in terms of the photocatalytic effect and carton processing suitability. Depending on the purpose, one or both sides can be cast. In the cast finishing, the surface temperature of the heated mirror drum is preferably 100 ° C. or higher.

  In the present invention, even a cast coated paper having a high white paper glossiness of 80% or more, preferably 85 to 98% according to JIS-P8142, can have a good effect. When the glossiness of white paper increases, the coating layer has a dense structure, the contact probability between the photocatalyst blended in the coating layer and harmful components in the air decreases, and the air cleaning effect tends to decrease. However, according to the production method of the present invention, even a cast coated paper having high white paper glossiness can exhibit an excellent air cleaning effect and can have high printability.

  In the present invention, a thin paper carton and a thin paper box are made using the coated paper.

  Next, a method for processing and manufacturing a thin paper carton and a thin paper box using the above coated paper will be described.

  The thin paper of the present invention is sanitary paper such as tissue, toilet paper, paper towel, table napkin, and wiper made of paper or nonwoven fabric.

  The method for producing the thin paper carton is not particularly limited, and for example, it is produced by the following method. Printing and processing of white board is outlined in Page 167 from Page 153 of white board / paper container '95 edition published by Paper Industries Times.

An example of manufacturing a thin paper box from a thin carton base paper (coated paper) will be described. Tissue paper carton base paper 640 g / m ² of the light entering the catalyst from a basis weight of 230 g / m ² created in the above method (coated paper), in order to improve the beautification of when used by consumers as thin paper box body Print the design, precautions, brand name, quality indication, JAN code, product characteristic appeal, and other indications. Printing can be mainly done by offset printing by lithographic printing, gravure printing by intaglio, etc. In addition, UV printing, silk screen printing by stencil, flexographic printing by letterpress, hot stamping that heat-presses foil film Can print. In hot stamp printing, a foil film of gold, silver or the like is overlaid as a printing layer.

  There is a tendency that the air cleaning effect and the deodorizing effect of the thin paper carton containing the photocatalyst are lowered by the ink layer and the printed layer of the film, and the printing area of the thin paper carton is preferably 1 to 80% per area exposed to light, more preferably 1 to 50%. If necessary, varnishing and glazing may be performed when producing a thin paper carton. However, this process can be omitted because the photocatalytic effect tends to be insufficient.

  The intermediate product of the thin paper carton after printing is subjected to a punching process. In the punching process, a punching process, a picking perforation process, and a ruled line forming process for folding the box are performed in the form of a development of the box. An embossing treatment may be performed in the punching process for cosmetics.

  Further, the intermediate product of the thin paper carton after the punching process is further adhered with a polyethylene film with slits by a window pasting machine using a vinyl acetate type, EVA type adhesive or the like. At present, many filmless thin paper boxes have been put on the market due to the environmental problem of waste reduction, and the present invention may also be a filmless thin paper box.

  Next, the intermediate product of the thin paper carton with or without the film is glued with a sack machine and boxed to produce the thin paper carton. The thin paper carton produced in this way is supplied to the tissue processing step. In tissue processing, by supplying thin paper cartons with a processing machine called cartoner, raising the thin paper cartons, inserting thin tissue paper such as tissue from the side of the thin paper cartons, sealing with adhesive and crimping A thin paper box containing thin paper can be obtained.

What is packed in a thin paper box in the present invention is sanitary paper such as household tissue, business use, industrial facial tissue, toilet paper, paper towel, table napkin, and wiper made of paper or non-woven fabric. A sheet shape such as a V-shaped fold, a C-shaped fold, a Z-shaped fold, or a roll shape may be used. FIG. 1 shows an example of a thin paper box produced in this way, and the surfaces A, B, C, D, and E of the thin paper box shown in FIG. area practical standpoint surface), it is preferable from the standpoint of the air cleaning effect and deodorizing effect of 400 cm ² is 2,000 cm ^2.

  EXAMPLES The present invention will be specifically described below with reference to examples, but of course not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a weight part and weight%, respectively. In addition, when producing a thin paper box from thin carton base paper, which is cast coated paper, and thin paper carton, a test was performed based on the following evaluation method.

(Evaluation methods)
(1) Particle measurement of titanium oxide: calculated from a photograph taken with an electron microscope.
The fine titanium oxide slurry was thinly applied on a data base for an electron microscope and dried with a drier set at 40 ° C. Thereafter, the FE-SEM (field emission scanning electron microscope / JSM-6700F, JSM-6700F) was photographed and observed at a photographing magnification of 10,000 times, and the average particle size of secondary particles was 100 particles. Calculated from the average value.
(2) Blank paper glossiness: 75 ° glossiness was measured according to JIS P 8142: 1988.
(3) Surface strength: Using an RI-II type printing tester, SMX tack grade 20 (black) ink manufactured by Toyo Ink Manufacturing Co., Ltd. was compared, and the dry pick strength was compared, and the strength was visually evaluated in the following four stages.
◎: Extremely excellent, ○: Excellent, △: Slightly problematic, ×: Problem present
(4) Photocatalytic effect: Evaluated by Photocatalyst Performance Evaluation Test Method IIb “Gas Bag B Method” established by the Photocatalyst Product Technical Council. The acetaldehyde decomposition rate (%) after irradiation with ultraviolet rays for 20 hours was measured, and evaluated according to the following four levels according to the decomposition rate.
◎: Very good (decomposition rate: 70% or more), ○: Somewhat excellent (same: 69-50%), △: Somewhat inferior (49: 10%), ×: Very poor (same: 10%) Less than)
(5) Fading test: Evaluation was made by measuring the decrease rate of ISO whiteness before UV irradiation and after UV irradiation (irradiating UV light with 2.5 mW / cm ² intensity with a black light) after 24 hours. .
Decrease rate of whiteness (%) = (Whiteness before UV irradiation−Whiteness after UV irradiation) / Whiteness before UV irradiation × 100
(6) Suitability of carton scratches: When making a box from a carton base paper, the difficulty of scratching the coating layer surface was visually evaluated in the following four stages.
(Double-circle): Very excellent, (circle): Somewhat excellent, (triangle | delta): Somewhat inferior x: It is quite inferior.
◎: Very good, ○: Somewhat excellent, △: Somewhat inferior, ×: Inferior
[Example 1]
Fine titanium oxide slurry A (CSB-M, Sakai Chemical Co., Ltd .; primary particle size 20-30 nm, secondary particle average particle size 1000 nm) 10 parts (solid content), colloidal silica (Nissan Chemical Snowtex 40) 16 parts Was stirred with a serie mixer for 1 hour. Among them, a pigment composed of 60 parts of primary kaolin (trade name: UW-90 / manufactured by Engelhard) and 30 parts of light calcium carbonate (TP121 / manufactured by Okutama Kogyo), 0.2 part of sodium polyacrylate as a dispersant. The pigment slurry added and dispersed with a serie mixer was added to prepare a pigment slurry having a solid content concentration of 60%.

Antifoaming agent (San Nopco 1407 / San Nopco) 0.5 part, release agent (Nopcoat C104 / San Nopco) 5 parts, styrene-butadiene copolymer latex A (glass transition temperature-10 ° C., particles as adhesive) 15 parts of diameter (190 nm) and 7 parts of casein were added (latex ratio: 68%), and water was further added to prepare a coating solution having a solid content of 50%. One side was coated on a white paperboard having a basis weight of 430 g / m ² with a blade coater so that the coating amount was 29 g / m ² and dried. The coated paper thus obtained was rewet on the surface of the coating layer with a rewetting liquid (polyethylene emulsion 0.5% concentration), and then passed through a press nip formed by a forming roll and a cast drum. / Min, pressed onto a cast drum having a surface temperature of 115 ° C., dried, and then released from the cast drum with a strip-off roll to obtain a cast coated paper having a basis weight of 460 g / m ² by a rewet cast method. This cast coated paper was used as a carton base paper for thin paper.

  The carton base paper for thin paper was printed so that letters and pictures would come on the faces A, B, C, D, and E in FIG. 1 when the thin paper box was formed in the printing process (offset printing). The printed area was 20% of the area of the whole surface of A + B + C + D + E. After that, a punching machine was used to punch out the shape of the box, and processing was performed so that the perforation for taking out the sewing machine and the ruled line for folding the box came to the part E on the top of FIG. .

  In addition, a film is pasted on the back side of the E side, which is the top surface of Fig. 1 with a window pasting machine, and then a vinyl acetate adhesive is applied to the glue area of the box developed by punching with a sack machine and folded and crimped. Went.

  Next, in the tissue processing manufacturing process (cartner) shown in FIG. 2, 180 sets of tissue were packed to obtain a box containing tissue.

[Example 2]
In Example 1, the cast paint was applied with a reverse roll coater attached to the cast coater so that the coating amount was 30 g / m ² per side, and then contacted with a coagulating liquid consisting of an aqueous calcium formate solution (10%). The wet coating layer is gelled, and the gelled coating layer is passed through a press nip formed by a forming roll and a cast drum, and pressed against a cast drum with a speed of 70 m / min and a surface temperature of 115 ° C. After drying, a box containing tissue was obtained in the same manner as in Example 1 except that the cast coated paper by the coagulation method was changed to a carton base paper for thin paper by releasing from the cast drum with a strip-off roll.

[Example 3]
In Example 1, to obtain a thin paper carton base paper is cast-coated paper having a basis weight of 360 g / ^{m 2} by using a white board for basis weight 330 g / ^{m 2} in place of the white board paper having a basis weight of 430 g / ^{m 2} .

  Next, printing was performed by offset printing so that the print area (A, B, C, D, E surface) was 40%. After the printing process in the manufacturing process of the thin paper carton described in Example 1, the same process was followed and the toilet paper was packed in the thin paper box processing process to obtain a box with toilet paper.

[Example 4]
In Example 1, fine titanium oxide slurry A (CSB-M manufactured by Sakai Chemical Co., Ltd .; primary particle diameter 20-30 nm, secondary particle average particle diameter 1000 nm) 10 parts (solid content), colloidal silica (Nissan Chemical Snow Co., Ltd.) Tex 40) Instead of 16 parts, fine titanium oxide slurry A (CSB-M manufactured by Sakai Chemical Co., Ltd .; primary particle diameter 20-30 nm, secondary particle average particle diameter 1000 nm) 10 parts (solid content), colloidal silica (Nissan) A box containing tissue was obtained in the same manner as in Example 1 except that it was changed to 10 parts by Snowtex 40 manufactured by Kagakusha.

[Comparative Example 1]
In Example 1, instead of 10 parts of titanium oxide slurry of coating liquid, 16 parts of colloidal silica, 60 parts of kaolin (trade name: UW-90 / manufactured by Engelhard), 30 parts of light calcium carbonate (TP121 / manufactured by Okutama Kogyo) In addition, a cast coated paper was obtained in the same manner as in Example 1 except that kaolin (trade name: UW-90 / manufactured by Engelhard) was changed to 70 parts and light calcium carbonate (TP121 / made by Okutama Kogyo) 30 parts. It was. This cast coated paper was used as a carton base paper for thin paper, and a box containing tissue was obtained in the same manner as in Example 1.

Table 1 shows the results.

  As is clear from Table 1, Examples 1 to 4 have high white paper gloss, and are excellent in photocatalytic effect, fading, carton damage suitability and carton processing suitability obtained from carton runnability. On the other hand, Comparative Example 1 is inferior in the photocatalytic effect, fading property, and carton processing suitability.

[Example 5]
<Preparation of topcoat coating solution>
Fine titanium oxide slurry (CSB-M, Sakai Chemical Co., Ltd .; primary particle diameter 20-30 nm, average particle diameter of secondary particles 1000 nm) 5 parts (solid content), colloidal silica (Nissan Chemical Snowtex 40) 8 parts The mixture was stirred for 1 hour with a serie mixer. Into the pigment, sodium polyacrylate was added as a dispersant to a pigment composed of 60 parts of heavy calcium carbonate (FMT-90 manufactured by Pfematec Co., Ltd.) and 35 parts of secondary clay (KCS manufactured by Imerys Co., Ltd.) Pigment 0.2 parts) A pigment slurry dispersed with a serie mixer was added to prepare a pigment slurry having a solid concentration of 71%. To the pigment slurry thus obtained, 13 parts of styrene / butadiene copolymer latex A (glass transition temperature 0 ° C., particle size 100 nm) and 5 parts of hydroxyethyl etherified starch (PG295 manufactured by Penford) were further added. Water was added to obtain a coating solution having a solid content of 63%.

<Preparation of undercoat coating solution>
To a pigment slurry consisting of 100 parts of heavy calcium carbonate (Fmatec FMT-90), add 6 parts of styrene / butadiene copolymer latex A and 5 parts of hydroxyethyl etherified starch (PG295 made by Penford) and water. Was added to obtain a coating solution having a solid concentration of 68%.
As the coating base paper, a white paperboard having a basis weight of 328 g / m ² was used.

The base paper was coated on both sides of the base paper using a blade coater at a coating speed of 500 m / min so that the coating amount per side was 8 g / m ² . Furthermore, double-side coating is performed using a blade coater at a coating speed of 500 m / min so that the coating amount per side of the top coating liquid is 8 g / m ² , and the coated paper moisture becomes 5%. Thus, a coated paper for printing having a basis weight of 360 g / m ² was obtained. The coated paper was a carton base paper for thin paper. The PPS roughness (backing material is a hard backing material having a hardness of 95 IRHD, the clamp pressure is 1000 kPa, measured according to ISO8791 / 4) was 3.2 μm. A box containing tissue was obtained from the carton base paper for thin paper in the same manner as in Example 1.

[Comparative Example 2]
In Example 5, instead of 5 parts of titanium oxide fine particle slurry (solid content), 8 parts of colloidal silica, 60 parts of heavy calcium carbonate, and 35 parts of secondary clay in the top coat liquid, 65 parts of heavy calcium carbonate, 2 parts A coated paper for printing obtained in the same manner as in Example 4 except that 35 parts of grade clay was used was used as a carton base paper for thin paper. The PPS roughness was 2.5 μm. A box containing tissue was obtained from the carton base paper for thin paper in the same manner as in Example 1.

Table 2 shows the results.

As is apparent from Table 2, Example 5 is excellent in the carton processing suitability obtained from the photocatalytic effect, the fading property, the suitability of scratching the carton and the running property of the carton. On the other hand, Comparative Example 2 is inferior in photocatalytic effect and fading.
Other evaluation methods are shown below.

(8) PPS roughness: measured based on ISO8791 / 4. The backing material was a hard backing material having a hardness of 95 IRHD, and the clamp pressure was measured at 1000 kPa.
(9) Glossiness of printing: Printed material obtained by printing at a printing speed of 8000 sheets / hour using a flat-land printing ink (High Unity L, manufactured by Toyo Ink Co., Ltd.) on a Roland flat-screen printing machine (4 colors). The surface of (4-color solid printing part) was measured based on JIS P8142.
(10) Printing surface feeling: Printed on a Roland flat printing machine (4 colors) using a flat printing ink (High Unity L manufactured by Toyo Ink Manufacturing Co., Ltd.) at a printing speed of 8000 sheets / hour. The ink inking unevenness and printing glossiness unevenness were visually evaluated in the following four stages.
A: Very good, B: Good, B: Slightly inferior, X: Inferior
(11) Choking resistance (powder removal after light irradiation): UV light with 2.5 mW / cm ² intensity is irradiated with black light for 5 hours, cellophane tape is applied to the coated paper surface, and then slowly peeled off. The degree to which it was difficult to adhere to the tape was visually evaluated in 4 stages.
◎: Extremely excellent, ○: Excellent, △: Slightly problematic, ×: Problem present

The perspective view which shows an example of the thin paper box which concerns on this invention. Explanatory drawing which shows the process used as the thin paper box which accommodated the thin paper in the thin paper carton which concerns on this invention.

Claims (7)

  In a carton for thin paper using a coated paper in which a coating layer mainly composed of a pigment and an adhesive is provided on the base paper, titanium oxide having an average secondary particle size of 300 nm to 2000 nm is used as the pigment 100 in the coating layer. A thin carton for thin paper, containing 1 to 30 parts by weight per part by weight.   In the coating layer, 5 to 40 parts by weight of an organic adhesive is blended with respect to 100 parts by weight of the pigment, and 50 to 90% by weight of the organic adhesive is a copolymer latex. Carton for thin paper as described.   The carton for thin paper according to claim 1 or 2, wherein a copolymer latex having a glass transition temperature of -20 to 40 ° C is used as an adhesive in the coating layer.   The carton for thin paper according to any one of claims 1 to 3, wherein a primary particle diameter of the titanium oxide is 5 to 100 nm.   The carton for thin paper according to any one of claims 1 to 4, wherein a cast coated paper for finishing a wet coated layer is used.   A carton for thin paper, wherein the coated paper according to any one of claims 1 to 5 is printed, punched, or boxed.   A thin paper box, wherein the thin paper is stored in the thin paper carton according to claim 6.

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