JP2015155582A - Water repellent oil-resistant paper having heat seal ability and production method of it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide oil-resistant paper for preventing impregnation of a fat component such as animal and vegetable oil and the like, excellent in bag packaging processing ability (heat seal ability) and excellent in moisture permeability and a production method of it.

SOLUTION: A coating liquid mainly formed of acrylic-resin emulsion having oil resistance and heat seal ability, and acrylic-resin emulsion having no heat seal ability but having water repellency are added to at least one surface of a substance, and then the coating liquid is coated and dried for forming a coating layer. Thereby, water repellent oil-resistant paper having heat seal ability is produced.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a water- and oil-repellent paper having heat sealing properties and a method for producing the same. Specifically, the present invention relates to a water- and oil-repellent paper that prevents permeation of oil and fat components such as animal and vegetable oils and fats, has excellent bag packaging processability, and excellent moisture permeability, and a method for producing the same.

Paper or paperboard is widely used for packaging materials such as food. In particular, oil-resistant paper and paperboard are used for food wrapping paper that contains a large amount of oil and fat components derived from animal and vegetable oils such as chocolate, pizza, and donuts, so that the oil and fat components of food do not penetrate into the packaging paper. Has been devised. When oil and fat components contained in food penetrate into the wrapping paper, the oil penetrates to the surface of the paper, creating an oil stain on the surface and impairing the appearance, and the printed part becomes black due to the oil stain and characters cannot be read. There is a possibility that the suitability of OCR such as a code and a QR code (registered trademark) may be lowered.
In addition, there are problems such as transfer of oil to clothes and contamination. For this reason, paper and paperboard which gave oil resistance to the part which touches food are used for the packaging paper of the foodstuff containing fats and oils components.
Furthermore, a coated paper obtained by processing a polyolefin such as polyethylene or polypropylene at a high speed by a T-die extrusion melt laminating method is generally used for the water and oil resistant paper. Paper coated with this polyolefin (laminate) is not only excellent in water resistance and oil resistance, but also is inexpensive, and is therefore frequently used as a packaging material. Such polyolefin laminated paper has oil repellency and water repellency, but is not completely oil resistant and has no function of releasing moisture (water vapor) of the contents to the outside.

  Oil resistant paper contains an oil resistant agent in order to exhibit oil resistance, and conventionally, a fluororesin-based oil resistant agent has been used as the oil resistant agent (for example, Patent Document 1). For example, oil-resistant paper in which a fluororesin-based oilproofing agent is applied to the surface of paper or paperboard to provide an oilproof layer, and oil-resistant paper in which a fluororesin-based oilproofing agent layer is provided between paper layers are known. However, when oil-resistant paper using a fluororesin-based oil-resistant agent is heated at a cooking temperature of 100 to 180 ° C., it is confirmed that components that tend to remain for a long time such as a fluorine-based alcohol compound having 8 to 10 carbon atoms are generated. ing. Also, when oil-resistant paper using these fluororesin-based oil-proofing agents is incinerated after use, fluorine compounds such as perfluorooctanoic acid and perfluorosulfonic acid are generated, and there is a concern that it may adversely affect health or the environment. ing.

  In order to solve these problems, oil-resistant paper using a polyvinyl alcohol-based resin as a non-fluorinated oil-resistant agent has been developed (for example, Patent Documents 2 and 3). Since the polyvinyl alcohol-based resin forms a strong hydrophilic film, it can prevent oil permeation and can exhibit excellent oil resistance. Fluorine-based oil resistant agents have exhibited oil resistance by utilizing the oil repellency derived from fluorine, whereas polyvinyl alcohol resins exhibit oil resistance due to the barrier effect of the coating layer film. Oil-resistant paper containing a non-fluorine-based oil resistant agent does not generate a fluorine compound or the like when heated, and thus has an advantage of high safety and low environmental burden.

However, when such a non-fluorine-based oil resistant agent is applied with a bar coater or a blade coater, coating defects such as foaming of the coating liquid and generation of bubbles in the oil resistant layer may occur. Furthermore, when foaming is severe, uneven coating occurs, which may reduce the oil resistance of the oil resistant layer.
In order to cope with such a problem, a method of adding a silicone-based antifoaming agent or a hydrophobic silica-based antifoaming agent to a coating liquid containing a non-fluorinated oilproofing agent has been proposed (for example, Patent Document 4 and 5). This suppresses foaming of the coating liquid and enhances the coating suitability.

  In addition, water resistance and oil resistance are provided with a coating layer that is a mixture of acrylic dispersion, styrene-butadiene dispersion and wax dispersion, and can be recycled for recovery and regeneration, etc. However, a water- and oil-resistant paper having printability imparted has been proposed (for example, Patent Document 6), but there is a problem that adhesion is insufficient when imparting heat sealability with a wax component.

JP 2009-120996 A JP 2011-26745 A JP 2011-185812 A Japanese Patent Laid-Open No. 11-277877 JP 2009-84404 A JP 2002-13095 A

As described above, the polyolefin laminated paper has oil repellency and water repellency. However, the polyolefin resin film has a problem in air permeability because vapor does not escape.
On the other hand, foaming at the time of coating can be suppressed to some extent by adding an antifoaming agent or the like to the coating liquid containing a non-fluorinated oilproofing agent. However, when the antifoaming agent itself has a strong lipophilicity, the oil penetrates and there is a problem that the oil resistant layer cannot sufficiently exhibit the oil resistance. That is, in the coating liquid containing the conventional non-fluorine-based oil resistant agent, coating stability and oil resistance are not compatible, and further improvement has been demanded.

  In addition, since the polyvinyl alcohol-based resin forms a strong hydrophilic film, it can prevent the permeation of oil, but there is a problem that it may permeate water and cannot exhibit sufficient water resistance. It was.

  Accordingly, the present inventors provide an oil-resistant paper having a good coated surface state, excellent heat sealability, and excellent oil resistance and water repellency (water resistance) in order to solve the problems of the conventional technology. We proceeded with a study for this purpose. In addition, the present inventors have also studied for the purpose of enhancing the production efficiency of water- and oil-repellent paper having heat sealability by forming an oil-resistant layer from a coating solution having excellent coating stability.

As a result of diligent studies to solve the above problems, the present inventors, as a coating liquid for forming an oil-resistant layer, the heat sealability is mainly composed of an acrylic resin emulsion having oil resistance and heat sealability. It has been found that the coating stability can be improved by adding an acrylic resin emulsion having no water repellency. Furthermore, the present inventors have found that the oil-resistant paper having the oil-resistant layer thus obtained has a good coated surface state and high heat seal adhesive force, and is excellent in oil resistance and water resistance. The present invention has been completed.
Specifically, the present invention has the following configuration.

[1] To a coating liquid mainly composed of an acrylic resin emulsion having oil resistance and heat sealability on at least one side of the substrate, an acrylic resin emulsion having no water sealability but water repellency is added, A water- and oil-repellent paper having heat sealability, wherein the coating layer is formed by applying and drying the coating solution.
[2] JAPAN TAPPI PAPER PULSE TEST METHOD No. ^{2 for} paper obtained by applying 5 g / m ^{2 of the} above acrylic resin emulsion having oil resistance and heat sealability onto a substrate and drying. 41: 2000 “Paper and paperboard—Oil repellency test method—Kit method” has a kit number of 6 or more, and has a water- and oil-repellent and heat-repellent property according to [1] paper.
[3] 5 g / m ^{2 of the} acrylic resin emulsion having oil resistance and heat sealability is applied and dried on a substrate, and the surfaces of the coating layers are thermocompression bonded at a temperature of 140 ° C. and a pressure of 2 kg / cm ² for 2 seconds. The water- and oil-repellent paper having heat sealing properties according to [1] or [2], wherein the base material breaks when T-peeled.
[4] JIS P 8137-1976 “Water repellency test of paper and paperboard” on paper obtained by applying and drying 5 g / m ^{2 of} acrylic resin emulsion having water repellency but not heat sealability. The water-repellent oil-resistant paper having heat sealability according to [1], wherein the water repellency measured according to “Method” is R6 or more.
[5] 100 parts by mass of the acrylic resin having oil resistance and heat sealability are contained in an amount of 1 to 20 parts by mass of an acrylic resin that does not have heat sealability but has water repellency [1] A water- and oil-repellent paper having heat sealing properties according to any one of to [4].
[6] The water- and oil-repellent paper having heat seal properties according to any one of [1] to [5], wherein the coating amount of the coating layer is 3.5 to 20.0 g / m ² .
[7] The heat sealability according to any one of [1] to [6], wherein the moisture permeability measured according to JIS K 7129: 2008 is 300 g / m ² · 24 h or more. Water repellent and oil resistant paper.
[8] The water- and oil-repellent paper having heat seal properties according to any one of [1] to [7], wherein the base material contains pulp as a main component.
[9] On at least one surface of the base material, an acrylic resin emulsion that does not have heat sealability but has water repellency is added to a coating liquid mainly composed of an acrylic resin emulsion having oil resistance and heat sealability. In the step of forming the coating layer, the coating solution is applied using a bar coater or a rod metering size press coater. A method for producing a water- and oil-repellent paper having heat sealing properties.
[10] A water- and oil-repellent paper having heat-sealability, which is produced by the production method according to [9].

  According to the present invention, it is possible to obtain a water- and oil-repellent paper having a good coated surface state, excellent heat sealability, and excellent oil resistance and water repellency (water resistance). In the present invention, the coating solution for the oil-resistant layer containing the oil-resistant agent is excellent in coating stability, so that the production efficiency of the water- and oil-repellent paper having heat sealability can be remarkably improved. Furthermore, since the water- and oil-repellent paper having heat sealability of the present invention has both oil resistance and water repellency (water resistance), it is preferably used as a packaging paper for foods and the like containing a large amount of oil and fat components and moisture.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Oil resistant paper)
The present invention relates to an oil-resistant paper having an oil-resistant layer excellent in heat sealability, water repellency and oil resistance, and a coating liquid mainly composed of an acrylic resin emulsion having oil resistance and heat sealability has heat sealability. The present invention relates to a water- and oil-repellent paper having a water-repellent acrylic resin emulsion added thereto, and applying and drying the coating liquid to form a coating layer. The water- and oil-repellent paper of the present invention can be used as packaging paper for foods containing oil and fat components, moisture, etc. It is possible to suppress the oil and fat component from leaching out while dissipating moisture (vapor) of the contents. The water- and oil-repellent paper having heat sealability of the present invention is used not only for packaging paper but also for sheets such as cooking paper, paper containers, and building material paper for kitchens that require oil resistance. You can also.
In addition, since the water- and oil-repellent paper of the present invention uses a non-fluorine-based oil-proof agent as an oil-proof agent, no fluorine compound is generated even when the water- and oil-repellent paper is heated or incinerated. For this reason, the water- and oil-repellent paper of the present invention has the advantages of high safety and low environmental load.

  In the present invention, the non-fluorinated oil-resistant layer means that the content of the fluorine-based oil resistant agent is 5% by mass or less, preferably 1% by mass or less, more preferably 0% by mass with respect to the oil-resistant layer. is there. The non-fluorinated oil resistant layer preferably uses a non-fluorinated oil resistant agent as the oil resistant agent, and preferably contains the following acrylic resins (A) and (B) as the non-fluorinated oil resistant agent.

(Water and oil repellent layer)
In the present invention, the acrylic resin (A) having oil resistance and heat sealability is copolymerizable with (a) (meth) acrylic acid alkyl ester monomer and (b) the (meth) acrylic acid alkyl ester monomer. It is a copolymer comprising at least one monomer selected from other monomers.

  The acrylic resin (B) having no water-sealability in the present invention but having water repellency includes (c) an ethylenically unsaturated carboxylic acid-containing monomer as an essential component, and (a) (meth) acrylic acid. An alkyl ester monomer; and (b) a copolymer comprising at least one monomer selected from other monomers copolymerizable with these monomers.

  Examples of the (a) (meth) acrylic acid alkyl ester monomer used in the present invention include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic 2-ethylhexyl acid, n-nonyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, ( Meta) dodecyl acrylate, etc., and at least one of them It is preferably used.

  (B) Other monomers copolymerizable with these monomers used in the present invention include styrene, vinyl acetate, vinyl chloride, vinylidene chloride, (meth) acrylonitrile, ethylene, propylene, 2-hydroxyethyl (meth) acrylate. 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol Mono (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) Chrylate, dipropylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane Tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, divinylbenzene, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate , Diallyl (meth) acrylate, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (Meth) acrylamide, N, N′-methylenebis (meth) acrylamide, sodium vinyl sulfonate, sodium p-styrene sulfonate, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphoxyethyl (meth) acrylate ethanolamine half Salt, sodium 3-allyloxy-2-hydroxypropanesulfonate, sodium polyoxyethylene styrenated phenyl sulfate, sodium glycerol monoallyl ether monosulfosuccinate, sodium 2-sulfoethyl (meth) acrylate, (meth) acrylamide, n-amyl (Meth) acrylate, isoamyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, capro Lactone-modified (meth) acrylate, acrolein, diacetone (meth) acrylamide, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, (meth) acrylooxyalkylpropenal, diacetone (meth) acrylate, acetonyl (meth) acrylate, acetoacetoxy Examples include ethyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, diallyl phthalate, triallyl cyanurate, and the like, and it is preferable to use at least one of these. Of these, styrene is particularly preferable in terms of adhesion.

  Examples of the (c) ethylenically unsaturated carboxylic acid-containing monomer used in the present invention include (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, monoalkylmaleic acid, monoalkylfumaric acid, and monoalkyl. Itaconic acid and the like can be mentioned, and it is preferable to use at least one of these. Among these, methacrylic acid is particularly preferable from the viewpoint of water repellency.

  In order to ensure coating suitability with a coater, it is preferable to control the high shear viscosity of the oil-resistant layer coating solution. If the viscosity is too low, the desired coating amount cannot be obtained and the oil resistance may deteriorate. If the high shear viscosity is too high, coating unevenness occurs on the coater, and a uniform coated surface cannot be obtained, and sufficient oil resistance may not be obtained.

In the present invention, for example, by controlling the weight average molecular weight and acid value of the acrylic resin (B) used in the oil-resistant layer, the high shear viscosity of the coating liquid is controlled to a desired viscosity range, and the oil-resistant layer coating liquid in the coater is controlled. Application suitability can be ensured.
Even if the weight average molecular weight is controlled within a predetermined range, if the acid value is 50 mgKOH or less, the viscosity at the time of application is lowered, and if it is 200 mgKOH or more, the viscosity is higher than the desired viscosity, so that applicability cannot be secured. There is.
On the other hand, even if the acid value of the acrylic resin (B) is controlled within a predetermined range, if the weight average molecular weight is 50,000 or less, the high shear viscosity becomes too low, and conversely if the weight average molecular weight exceeds 2 million. In addition, the high shear viscosity of the oil-resistant layer coating solution becomes too high, and thus there is a possibility that application suitability cannot be ensured.

In the present invention, in order to control the high shear viscosity of the oil-resistant layer coating solution containing the acrylic resin (B), the acid value is adjusted to 50 to 200 mgKOH, more preferably by adjusting the blending amount of the ethylenically unsaturated carboxylic acid-containing monomer. It is 70-180 mgKOH, Most preferably, it is 100-150 mgKOH.
When the acid value of the acrylic resin is less than 50 mgKOH, the mechanical stability, re-solubility, viscosity, etc. of the resin are inferior, and the polymerization stability and application suitability are adversely affected. In particular, the high shear viscosity of the oil-resistant layer coating solution becomes too low, and a desired coating amount cannot be obtained, resulting in deterioration of oil resistance. Conversely, when the acid value exceeds 200 mgKOH, the drying and water resistance of the oil-resistant layer coating film is poor, and the coating film becomes too hard, so that cracks are likely to occur and the oil resistance deteriorates. Here, the acid value is the number of mg of KOH required to neutralize free fatty acids contained in 1 mg of resin.

  The acrylic resins (A) and (B) used in the present invention can be obtained by a known emulsion polymerization method. For example, it can be obtained by charging the above-mentioned various monomers, emulsifier and water in a predetermined reaction vessel, adding a radical polymerization initiator, and heating with stirring.

  Examples of radical polymerization initiators include persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, peroxides such as hydrogen peroxide, t-butyl hydroxide, and t-butyl peroxybenzoate, and 2,2-azo. Examples thereof include azo compounds such as bisisobutyronitrile, 2,2-azobis (2-diaminopropane) hydrochloride, and 2,2-azobis (2,4-dimethylvaleronitrile). If acceleration of polymerization rate or low temperature reaction is desired, a reducing agent such as sodium bisulfite, ferrous chloride, ascorbic acid, formaldehyde sulfooxylate salt is combined with the radical polymerization initiator (redox polymerization initiation). Agent).

  Although the usage-amount of a polymerization initiator is 0.02-3 mass parts normally with respect to 100 mass parts of monomer components, Preferably it is 0.05-1 mass part.

The emulsifier to be used is not particularly limited, and examples thereof include an anionic emulsifier, a nonionic emulsifier, and a reactive emulsifier.
Examples of anionic emulsifiers include fatty acid metal salts such as potassium oleate, alkyl sulfates such as sodium lauryl sulfate, alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate, alkyl sulfonates such as sodium alkyl naphthalene sulfonate, and dialkyl sulfosuccinates. Examples thereof include sodium acid, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl allyl ether phosphate, and the like.
Nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block polymers, polyethylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and the like.
As reactive emulsifiers, polyethylene glycol mono (meth) acrylate, polyoxyethylene alkylphenol ether (meth) acrylate, ammonium 2- (meth) acryloyloxyethylsulfonate, polyethylene glycol having various molecular weights (different EO addition mole numbers) Monomaleic acid esters and derivatives thereof, (meth) acryloyl polyoxyalkylene alkyl ether phosphates, and the like.

  The amount of the emulsifier used is usually about 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the monomer component. By using the amount of the emulsifier within this range, an acrylic resin emulsion having an appropriate average particle diameter can be obtained without producing a coagulated product.

  The acrylic resin used in the present invention is obtained by an emulsion polymerization method in an aqueous medium as described above. The acrylic resin emulsion has a solid content concentration of 30 to 75% by mass, preferably about 40 to 65% by mass. be able to. In the case of starting single polymerization, the polymerization reaction is usually performed at a reaction temperature of about 40 to 95 ° C., preferably about 60 to 90 ° C., for 1 to 10 hours, preferably about 4 to 8 hours. In the case of a redox polymerization initiator, the reaction temperature is lower, usually 5 to 90 ° C, preferably about 20 to 70 ° C. As a monomer addition method, a batch addition method, a divided addition method, a continuous addition method, or the like, such as a monomer tap method or a monomer pre-emulsification tap method can be used. The monomer pre-emulsification tapping method is preferred by the continuous addition method.

  The acrylic resin emulsion used in the present invention preferably has an average particle size of 0.01 to 1.0 μm. If the average particle diameter is within this range, water dispersibility will be good. If the average particle size is less than 0.01 μm, the mechanical stability at the time of application may be deteriorated. If it exceeds 1.0 μm, the high shear viscosity is low, and a desired application amount may not be obtained, There is a risk of uneven coating such as streaks. In addition, about an average particle diameter, it can adjust by setting suitably the kind and addition amount, addition method, stirring conditions, etc. of an emulsifier and a polymerization initiator. Here, the average particle size of the emulsion is measured with a light scattering particle size distribution analyzer (trade name: “LA-950”, manufactured by HORIBA).

  In the present invention, it is necessary to control the high shear viscosity of the water-repellent and oil-resistant layer coating liquid in order to ensure coating suitability with a coater. Therefore, when the acrylic resin is emulsion-polymerized, the molecular weight (weight average molecular weight) can be appropriately adjusted by controlling the reaction temperature, reaction time, average particle diameter, and acid value. Furthermore, it is a preferred embodiment to use a known chain transfer agent. Examples of such chain transfer agents include butyl mercaptan, dodecyl mercaptan, octyl thioglycolate, isopropyl alcohol, methanol, carbon tetrachloride and the like. The usage-amount is 0.001-2.0 mass parts with respect to 100 mass parts of monomer components, Preferably it is 0.05-1.0 mass part.

  The glass transition temperature of the acrylic resin used in the present invention is preferably 50 ° C. or lower, may be 20 ° C. or lower, and may be 0 ° C. or lower. Thus, by setting the glass transition temperature (Tg) to 50 ° C. or less, the oil resistant layer can exhibit high film forming ability and excellent oil resistance. In the present invention, Tg is obtained by differential scanning calorimetry (DSC) according to the method for measuring the transition temperature of JIS K 7121-1987 plastic.

  The acrylic resin used in the present invention preferably has an average particle size of 0.01 to 1.0 μm. If the average particle diameter is within this range, water dispersibility will be good. If the average particle size is less than 0.01 μm, the mechanical stability during coating may be deteriorated, and if it exceeds 1.0 μm, the high shear viscosity is low, and a desired coating amount cannot be obtained. There is a risk that coating defects such as streaks may occur on the coated surface. Here, the average particle size of the resin emulsion is measured with a light scattering particle size distribution analyzer (trade name: LA-950, manufactured by HORIBA).

As the acrylic resin (acrylic resin (A)) having heat sealability used in the present invention, a paper prepared by applying JAPAN TAPPI paper pulp test method No. 5 on a base material coated with 5 g / m ^{2 of the} resin and dried. It is preferable that the kit number measured based on 41: 2000 "paper and paperboard-oil repellency test method-kit method" is 6 or more.
If the kit number is less than 6, the oil content of the food in the package may ooze out.

Moreover, as an acrylic resin (acrylic resin (A)) having heat sealing properties used in the present invention, the resin is applied and dried at 5 g / m ^{2 on a} substrate, and the temperature of the coating layers is 140 ° C. It is preferable that the substrate breakage occurs when the pressure is 2 Kg / cm ² and the thermocompression bonding is performed for 2 seconds and the T-shaped peeling is performed.
In the said thermocompression bonding conditions, when base material peeling does not generate | occur | produce at the time of T character peeling, there exists a possibility that an adhesion part may peel and a bag packaging may be torn.

  Specific examples of the acrylic resin (A) used in the present invention include a trade name: “Yodosol AE41” (Tg: 5 ° C.) manufactured by Henkel Japan, which is a styrene- (meth) acrylic acid alkyl ester copolymer, A product name “Cartaseal SW-DP” manufactured by Chrome Japan Co., Ltd. may be mentioned.

As an acrylic resin (acrylic resin (B)) having no water-sealing property but having water repellency used in the present invention, a JIS P of paper obtained by applying and drying 5 g / m ^{2 of the} resin on a substrate. It is preferable that the water repellency measured according to 8137-1976 “Test method for water repellency of paper and paperboard” is R6 or more.
If the water repellency is less than R6, the paper may be broken by the moisture of the food.

  Moreover, as a specific example of acrylic resin (B) used in the present invention, a product name manufactured by Clariant Japan Co., Ltd., which is a methacrylic acid- (meth) acrylic acid alkyl ester-styrene copolymer: “Cartaseal HFU” (Tg : 20 ° C.), trade name manufactured by Meisei Chemical Co., Ltd .: “Maycatex HP-68C”, product name “Size Pine W-116H” manufactured by Arakawa Chemical Co., etc.

In this invention, it is preferable to contain 1-20 mass parts of acrylic resin (B) with respect to 100 mass parts of acrylic resin (A). When content of acrylic resin (B) exceeds 20 mass parts, there exists a possibility that the adhesion defect of a heat seal part may generate | occur | produce. On the other hand, if the content is less than 1 part by mass, the water repellency becomes too low, and the paper may be broken by the moisture of the food.
As a preferable range of content of acrylic resin (B), it is 3-18 mass parts, More preferably, it is 5-15 mass parts.

  In the present invention, it is necessary to control the viscosity of the oil-resistant layer coating solution in order to ensure coating suitability in a bar coater or a rod metering size press coater. For this reason, it is preferable that the molecular weight (weight average molecular weight) of acrylic resin shall be 50,000-2 million. The molecular weight of the acrylic resin can be appropriately adjusted by controlling the reaction temperature, reaction time, average particle size, and acid value during polymerization. Furthermore, you may use a well-known chain transfer agent. Examples of such chain transfer agents include butyl mercaptan, dodecyl mercaptan, octyl thioglycolate, isopropyl alcohol, methanol, carbon tetrachloride and the like. The usage-amount is 0.001-2.0 mass parts with respect to 100 mass parts of monomer components, Preferably it is 0.05-1.0 mass part.

  In addition, the water-repellent and oil-resistant layer coating solution may be added with various commonly used auxiliaries such as a dispersant, a thickener, a water retention agent, an antifoaming agent, and a colorant, if necessary. . The content of these auxiliaries is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 1% by mass or less, based on the total solid mass of the oil-resistant layer. preferable.

(Base material)
The substrate used in the water- and oil-repellent paper of the present invention is not particularly limited as long as it can be provided with a water- and oil-repellent layer on at least one surface. It is preferable to use one. For example, high-quality paper, medium-quality paper, fine-coated paper, coated paper, glossy paper, bleached or unbleached kraft paper (acidic paper or neutral paper), or for corrugated board, for building materials, for white balls, Paperboard, white paperboard or the like used for chipboard can be used. Although there is no restriction | limiting in particular in the basic weight of a base material, 150-500 g / m < ² > is suitable for molded containers, such as 20-150 g / m < ² > and boxes, for wrapping paper.

  As the pulp constituting the substrate, any of those usually used for papermaking can be used. For example, chemical pulp such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood bleached sulfite pulp (LBSP), softwood bleached sulfite pulp (NBSP), stone grand pulp (GP), pressure stone Unbleached, semi-bleached or bleached pulp, sulfite pulp, waste paper such as ground pulp (PGW), refiner ground pulp (RGP), chemiground pulp (CGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP) Pulp etc. can be used. In blending the pulp of the base material, it is preferable to blend a large amount of LBKP excellent in dimensional stability, and it is preferable to blend 60 to 100% by mass of 100% by mass of the total pulp.

The basis weight of the substrate that can be used in the present invention is preferably 20 to 70 g / m ² , and the Oken air permeability is preferably 70 seconds or more. By setting the basis weight of the base material within the above range, it is possible to maintain a required strength that can maintain a required strength when the oil-resistant layer is formed. When the basis weight of the base material exceeds 70 g / m ² , the base material is likely to buckle at the fold portion, so that the base material is cracked and the oil resistance of the fold tends to be lowered. In addition, the JAPAN TAPPI paper pulp test method No. When the Oken air permeability measured according to 5-2: 2000 is less than 70 seconds, the elongation of the folded portion of the base paper becomes small, and the oil resistance tends to decrease. The upper limit of the Oken air permeability is not particularly limited, but is preferably 400 seconds or less.

  Furthermore, in order to increase the air permeability of the base material, it is preferable that the Canadian standard freeness measured by pulsing the pulp to be used according to JIS P 8121-1995 is 300 ml or less. A more preferable range of beating degree is 80 to 250 ml. By setting the beating degree within the above range, the oil resistance of the entire oil resistant paper can be enhanced.

  In addition, the pulp to be used has been described above using a beater such as a beater, a Jordan, a single disc refiner, a conical refiner, a cylindrical refiner, a deluxe refiner, a double disc refiner (DDR), a medium agitating mill, a vibration mill, or the like. It is adjusted to be beaten. The beating conditions are not particularly limited, but the shape of the refiner blades, rotation speed, pulp concentration, pulp fiber length, pulp roughness, etc. will affect the physical properties of the pulp after beating, so the desired beating degree can be obtained. The beating conditions are selected as appropriate.

In order to enhance the air permeability of the base material, it is preferred that the density of the base material and 0.8~1.2g / cm ^3, and more preferably to 0.85~1.1g / cm ³ . Specific methods for increasing the density of the substrate include applying pressure in the wet paper state when making the substrate, using a machine calendar, soft nip calender, gloss calendar after drying, or using a super calender after making the substrate. It may be used.

  Further, the thickness of the substrate is preferably 50 μm or more, and more preferably 70 μm or more. Further, the thickness of the substrate is preferably 500 μm or less, and more preferably 300 μm or less. By setting the thickness of the substrate within the above range, it is possible to have an appropriate strength and to improve the coating suitability of the oil resistant layer.

  The substrate may further contain an additive. As additives, sizing agents represented by rosin, alkyl ketene dimer, alkenyl succinic acid, etc., fixing agents represented by sulfuric acid bands, cationic polymer electrolytes, clay, talc, calcium carbonate, calcined kaolin, aluminum oxide, Aluminum hydroxide, titanium oxide, amorphous silica, fillers typified by urea-formalin resin particles, polyacrylamide polymers, paper strength enhancers typified by starch, melamine resins, urea resins, polyamide-polyamines Examples include wet paper strength enhancers typified by epichlorohydrin resins and the like, and other auxiliaries such as dyes, pigments, and fluorescent dyes for color tone adjustment such as filtering agents and bluing.

(Manufacturing method of water and oil repellent paper)
<Manufacturing method of substrate>
The base material can be obtained by making paper with various paper machines by a conventional method, forming wet paper, and then drying. The base material preferably contains starch, polyvinyl alcohol, gelatin, filler, etc., if necessary, and is preferably manufactured through a conventional process such as a smoothing process using a surface size press machine calendar. .
Examples of the paper machine used in the present invention include a long net paper machine having an air cushion head box or a hydraulic head box, a twin wire paper machine, an on-top type twin wire paper machine, and a Yankee paper machine.

<Method for producing water- and oil-repellent layer>
As a coating method for the water and oil repellent and oil resistant layer of the present invention, generally known coating devices can be used, for example, blade coater, air knife coater, roll coater, reverse roll coater, bar coater, curtain coater, slot die coater. For example, a coater, a gravure coater, a champlex coater, a brush coater, a slide bead coater, a two-roll or metering blade type size press coater, a bill blade coater, a short dwell coater, a gate roll coater, a nip coater using a calendar, and the like are appropriately used. Among these, in order to increase production efficiency, it is preferable to use a bar coater or a rod metering size press coater, and it is more preferable to use a rod metering size press coater.

  In addition, by using a bar coater or a rod metering size press coater, high-speed coating becomes possible and production efficiency can be increased. However, coating by a bar coater or rod metering size press coater is as described above. It is performed under the harshest conditions among various coating methods. This means that heat and pressure are likely to be applied to the coating liquid during coating with a bar coater or a rod metering size press coater. In addition, when reducing the coating amount and reducing the paint to be dried, it is necessary to increase the pressing pressure of the rod when scraping a lot of coating liquid using a rod metering size press coater, It tends to be an excessive pressing pressure and tends to cause streaks.

However, in the present invention, by including an acrylic resin having a specific composition in the water- and oil-repellent layer, even when coating is performed using a bar coater or a rod metering size press coater. It is possible to improve the coating state without causing any problems. That is, the coating liquid used in the present invention does not increase the viscosity of the coating liquid even after coating using a bar coater or a rod metering size press coater. The immobilization can be prevented. Moreover, the occurrence of streaks due to the pressing pressure of the rod can be suppressed.
Thus, in the present invention, the water- and oil-repellent layer can be applied by a bar coater or a rod metering size press coater, and it can be applied even under such severe conditions. It means that the workability is sufficiently high.

The coating amount of the water-repellent oil resistant layer of the present invention is preferably in the range of 3.5~20.0g / ^{m 2,} more preferably in the range of 4.0~18.0g / ^{m 2,} More preferably, it is in the range of 5.0 to 10.0 g / m ² . By setting the coating amount of the water / oil repellent layer within the above range, a water / oil repellent layer capable of exhibiting sufficient oil resistance can be obtained.
In the present invention, only one layer of the water / oil repellent layer may be provided on at least one side of the substrate, but a plurality of layers may be provided on at least one side of the substrate. When the same coating amount is applied, a water / oil-repellent and oil-resistant layer tends to be obtained more easily in a multi-layer configuration than in a single-layer configuration. When the water / oil-repellent layer has a multi-layer structure, the number of layers is preferably 2 to 5 layers, and more preferably 2 to 4 layers. In the case of a multi-layer configuration, each layer may have the same configuration (composition) or may be different. In addition, when the water / oil repellent layer is a plurality of layers, the total coating amount is preferably within the above range.

After applying the water and oil repellent agent on one side of the substrate, a step of drying the water and oil repellent agent is provided.
Further, in the present invention, after forming the water- and oil-repellent and oil-resistant layer, a smoothing treatment can be performed as necessary. The smoothing process is performed on-machine or off-machine using a smoothing processing apparatus such as a normal super calendar, gloss calendar, or soft calendar.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>
(1) Preparation of sheet With respect to 100 parts of an acrylic emulsion resin having oil resistance and heat seal properties (Yodosol AE-41 made by Henkel Japan), an acrylic emulsion resin having a water repellency (Caltical HFU made by Clariant Japan) is used. A coating liquid (I) to which 1 part was added was prepared. The obtained coating liquid (I) was applied onto a fine paper of 50 g / m ^{2 with} a Mayer bar and dried at 5 g / m ² to prepare a sheet (I).

(2) Adhesive evaluation The coated surfaces of the sheet (I) were heat-pressed at 140 ° C. for 2 seconds using a TP-701S heat seal tester manufactured by Tester Sangyo Co., Ltd. .

(3) Evaluation of oil resistance and water repellency About sheet (I) JAPAN TAPPI Paper Pulp Test Method No. The oil resistance was measured according to 41-83, and the water repellency was measured according to JIS P 8137 “Testing method for water repellency of paper and paperboard”.

(4) Evaluation of moisture permeability The moisture permeability of the sheet (I) was evaluated in accordance with JIS K 7129: 2008.

<Example 2>
A coating liquid in which 10 parts of an acrylic emulsion resin having a water repellency (Caltasal HFU made by Clariant Japan) is added to 100 parts of an acrylic emulsion resin having oil resistance and heat sealing properties (Yodosol AE-41 made by Henkel Japan). (II) was prepared. The obtained coating liquid (II) was coated on a fine paper of 50 g / m ^{2 with} a Mayer bar at 5 g / m ² and dried to prepare a sheet (II). Adhesion and oil resistance were obtained in the same procedure as in Example 1. Water repellency and moisture permeability were evaluated.

<Example 3>
A coating liquid in which 20 parts of an acrylic emulsion resin having a water-repellent property (Calaseal HFU made by Clariant Japan) is added to 100 parts of an acrylic emulsion resin having oil resistance and heat sealability (Yodosol AE-41 made by Henkel Japan). (III) was prepared. The resulting coating solution (III) and 5 g / ^{m 2} coated with Meyer bar on a high-quality paper of 50 g / ^{m 2,} and dried to create a sheet (III), adhesion in the same manner as in Example 1, oil resistance Water repellency and moisture permeability were evaluated.

<Example 4>
A coating liquid in which 10 parts of an acrylic emulsion resin having a water repellency (Caltasal HFU made by Clariant Japan) is added to 100 parts of an acrylic emulsion resin having oil resistance and heat sealing properties (Yodosol AE-41 made by Henkel Japan). (IV) was prepared. The obtained coating liquid (IV) was applied onto a high-quality paper of 50 g / m ^{2 with} a rod metalling size press coater at 5 g / m ² and dried to prepare a sheet (IV), which was then bonded in the same procedure as in Example 1. Property, oil resistance, water repellency and moisture permeability were evaluated.

<Example 5>
A coating liquid in which 10 parts of an acrylic emulsion resin having a water repellency (Caltasal HFU made by Clariant Japan) is added to 100 parts of an acrylic emulsion resin having oil resistance and heat sealing properties (Yodosol AE-41 made by Henkel Japan). (V) was prepared. The resulting coating liquid (V) to 3 g / m ² coated with Meyer bar on a high-quality paper of 50 g / m ^2, and dried to create a sheet (V), the adhesive in the same manner as in Example 1, oil resistance Water repellency and moisture permeability were evaluated.

<Comparative Example 1>
A sheet (VI) is prepared by applying 5 g / m ² of an acrylic emulsion resin (Hendkel Japan Co., Ltd. Yodosol AE-41) having oil resistance and heat sealability onto a high quality paper of 50 g / m ^{2 with} a Mayer bar and drying. The adhesiveness, oil resistance, water repellency and moisture permeability were evaluated in the same procedure as in Example 1.

<Comparative Example 2>
A coating liquid (VII) was prepared by adding 10 parts of SBR latex (L-1571 manufactured by Asahi Kasei Co., Ltd.) to 100 parts of acrylic emulsion resin (Hendel Japan Co., Ltd. Yodosol AE-41) having oil resistance and heat sealability. . The obtained coating solution (VII) was coated on a high-quality paper of 50 g / m ^{2 with} a Mayer bar at 5 g / m ² and dried to prepare a sheet (VII). The same procedure as in Example 1 was followed for adhesion and oil resistance. Water repellency and moisture permeability were evaluated.

<Comparative Example 3>
A coating liquid (VIII) was prepared by adding 10 parts of an acrylic emulsion resin having a water repellency (Caltical HFU manufactured by Clariant Japan) to 100 parts of ethylene-vinyl acetate copolymer resin (Polysol AM3150 manufactured by Showa Denko KK). . The obtained coating solution (VIII) was coated on a high-quality paper of 50 g / m ^{2 with} a Mayer bar at 5 g / m ² and dried to prepare a sheet (VIII). The same procedure as in Example 1 was followed for adhesion and oil resistance. Water repellency and moisture permeability were evaluated.

  The sheets obtained in Examples and Comparative Examples were evaluated for adhesiveness, oil resistance, water repellency, and moisture permeability, and the results are shown in Table 1.

  As shown in Table 1, by providing a heat seal layer in which an acrylic emulsion resin having water repellency is added to a resin layer mainly composed of an acrylic emulsion resin having oil resistance and heat sealability on the base paper, moisture permeability is improved. Well, oil-resistant and water-resistant paper excellent in heat sealability could be obtained.

Claims (10)

  To the coating liquid mainly composed of an acrylic resin emulsion having oil resistance and heat sealability on at least one side of the substrate, an acrylic resin emulsion having no heat seal property but water repellency is added, and the coating liquid A water- and oil-repellent paper having heat-sealability, wherein a coating layer is formed by coating and drying. JAPAN TAPPI Paper Pulp Test Method No. 1 was applied to a paper obtained by applying 5 g / m ² of an acrylic resin emulsion having oil resistance and heat sealability onto a substrate and drying. 41: 2000 Water and oil repellency with heat sealability according to claim 1, characterized in that the kit number measured in accordance with 41: 2000 "Paper and paperboard-Oil repellency test method-Kit method" is 6 or more. paper. The above-mentioned acrylic resin emulsion having oil resistance and heat sealability is applied and dried on a substrate at 5 g / m ^2, and the surfaces of the coating layers are thermocompression bonded at a temperature of 140 ° C. and a pressure of 2 kg / cm ² for 2 seconds to form a T-shape. The water- and oil-repellent paper having heat sealability according to claim 1 or 2, wherein the base material breaks when peeled. According to JIS P 8137-1976 “Testing method for water repellency of paper and paperboard” of 5 g / m ² coated and dried acrylic resin emulsion having water repellency but not heat sealability. 2. The water- and oil-repellent paper having heat sealability according to claim 1, wherein the water repellency measured in conformity with the water repellency is R6 or more.   Applying and drying a coating solution containing 1 to 20 parts by mass of an acrylic resin that does not have heat sealability but has water repellency in 100 parts by mass of the acrylic resin having oil resistance and heat sealability, and then drying the coating layer The water- and oil-repellent paper having heat sealability according to any one of claims 1 to 4, which is formed. Repellent oil paper having a heat sealing property according to any one of claims 1 to 5, wherein the coating amount of the coating layer is 3.5~20.0g / m ^2. The water-repellent and oil-repellent paper having heat sealability according to any one of claims 1 to 6, wherein the moisture permeability measured in accordance with JIS K 7129: 2008 is 300 g / m ² · 24 h or more. .   The water- and oil-repellent paper having heat sealability according to any one of claims 1 to 7, wherein the base material contains pulp as a main component.   On at least one surface of the substrate, an acrylic resin emulsion that does not have heat sealability but has water repellency is added to a coating solution mainly composed of an acrylic resin emulsion having oil resistance and heat sealability. A step of forming a coating layer by applying and drying a solution, wherein the coating solution is applied using a bar coater or a rod metering size press coater. A method for producing a water and oil repellent paper having heat sealability.   A water- and oil-repellent paper having heat-sealability, which is produced by the production method according to claim 9.