WO2013008938A1

WO2013008938A1 - Food packaging paper

Info

Publication number: WO2013008938A1
Application number: PCT/JP2012/068016
Authority: WO
Inventors: 秀治辻内; 孝志吉本; 成博和田
Original assignee: 大阪印刷インキ製造株式会社; 株式会社ヨシモト印刷社; 睦化学工業株式会社
Priority date: 2011-07-14
Filing date: 2012-07-13
Publication date: 2013-01-17
Also published as: TW201326515A; JP2013035600A

Abstract

A food packaging paper which has water resistance, oil resistance, curling resistance and releasability without damaging the air permeability and moisture permeability of paper, is not fused by heat of steam or oil generated from a food in the course of re-heating, and can be easily opened. The food packaging paper is obtained by forming a coating layer by the flexo printing method on a paper with a basis weight of 19-700 g/m² and then drying the same, said coating layer being formed of a filler-containing water-based varnish which comprises, as the main component, an acid-containing copolymer consisting of one or more kinds of (meth)acrylate-based monomers and one or more kinds of vinyl-based monomers and having a glass transition point of -10^oC to 50^oC.

Description

Food wrapping paper

The present invention relates to a food packaging paper coated with a coating agent in order to prevent the moisture and oil of the food from seeping out to the outer surface and to prevent the food containing moisture from adhering to the packaging paper.

Currently, fast food wrapping paper such as hamburgers prevents food moisture and oil from leaching to the outside, prevents moisture-containing food from adhering to the wrapping paper (release), and heat-sealed bags. Most of the paper is polyethylene-laminated paper laminated with polyethylene on the surface that comes into direct contact with food (see Patent Document 1 below). However, when polyethylene, which is significantly inferior in moisture permeability and air permeability as compared with paper, is laminated, vapor generated from hot food tends to condense on the polyethylene surface, and the food tends to be sticky.

In addition, fast food may be heated again in a microwave oven, and polyethylene laminated paper may not be able to open the wrapping paper easily due to the softening and fusion of polyethylene due to the heat and oil of steam generated from food. is there.

In addition, since polyethylene laminated paper cannot be disaggregated as waste paper, there is a problem that it is impossible to recycle in a general waste paper recycling line, and only a dedicated recycling line can be processed.

There is also a method of coating water and oil resistance to fast food wrapping paper by coating the paper with a fluororesin. However, when such paper is incinerated, it may affect the environment. Hydrogen fluoride may be generated. Currently, there is no provision for fluororesins in the Food Sanitation Law. However, fluororesins cannot wipe out the possibility of affecting the global environment and human health. It has been.

Furthermore, as a paper that has been given water resistance and oil resistance to the fast food wrapping paper, there is a wax paper in which the paper is impregnated or surface-coated with waxes such as paraffin wax and carnauba wax, particularly steam and oil such as a hamburger. When a food containing a large amount of is packaged, there is a problem in water resistance and oil resistance. Further, depending on the amount of heat of the heated food, the wax may remelt and adhere to the food.

In general, when a water-based coating agent is applied to a thin paper such as a thin paper, the paper swells, and the resin impregnated in the meantime dries to form a film. The processing suitability at the time of cutting or molding may be significantly reduced. As a general method for solving this problem, there is a method of adding a polyhydric alcohol solvent such as glycerin or propylene glycol having high moisture retention as a moisture adjusting agent for paper to the coating agent, but as a fast food wrapping paper containing moisture. When used, there is a possibility that the water resistance of the coating agent is lowered and the ingredients of these humectants adhere to food due to bleeding.

Japanese Patent Laid-Open No. 9-2540

The present invention has water resistance, oil resistance, curl resistance, and release properties that are indispensable for food packaging without impairing the air permeability and moisture permeability of the paper, and is further heated by a microwave oven or the like. Another object of the present invention is to provide a food wrapping paper that can be easily opened without being fused by the heat of steam or oil generated from the food.

(1) The main component is an acid-containing copolymer formed from one or more (meth) acrylate monomers and one or more vinyl monomers, and having a glass transition point of −10 ° C. to 50 ° C. And having a coating layer formed by applying and drying an aqueous varnish containing a filler on a paper having a weight of 19 to 700 g / m ^{2 by} a flexographic printing method, and having air permeability, moisture permeability, water resistance and oil resistance. Wrapping paper for foods that has excellent curling resistance and food release properties.
(2) The food according to (1), wherein the aqueous varnish further contains at least one additive selected from a wax, an antifoaming agent, a dispersant, and a leveling agent. Wrapping paper.
(3) The acid-containing copolymer is one or more selected from butyl acrylate (BA), ethyl acrylate (EA), ethyl methacrylate (EMA), methyl acrylate (MA), methyl methacrylate (MMA), and N-propyl methacrylate. The monomer is contained so as to be 50% by weight or more of the total monomer constituting the acid-containing copolymer, and acrylic acid (AA), fumaric acid, glycidyl methacrylate (GMA), N-hexyl methacrylate (HMA), itaconic acid, methacrylic acid (MAA) containing at least one monomer selected from (MAA) in an amount of 5% by weight or less of the total monomer constituting the acid-containing copolymer, and acrylonitrile, butadiene, 2-ethylhexyl acrylate, styrene, vinyl acetate, vinyl The above-mentioned (1), which is a polymer obtained by copolymerizing one or more monomers selected from rholide and vinylidene chloride so as to be 50% by weight or less of the total monomers constituting the acid-containing copolymer. ) Or (2) food packaging paper.
(4) The foodstuff according to any one of (1) to (3), wherein the filler is one or more fillers selected from calcium carbonate, talc, kaolin, and mica. wrapping paper.
(5) The food packaging paper as described in any one of (1) to (4) above, wherein the dry thickness of the coat layer is 3 to 15 g / m ² .
(6) All the constituents described in the positive list of FDA 176.170 and further having a composition with no restrictions on FDA use conditions (food type, temperature limit) (1) Thru | or the packaging paper for foodstuffs as described in any one of (5).
(7) The food packaging paper according to any one of (1) to (6), wherein the food packaging paper is used for fast food.

Since the food wrapping paper of the present invention has the above-described configuration, it also has water resistance, oil resistance, release properties that are indispensable for food packaging, while maintaining the breathability and moisture permeability of the paper, and also a microwave oven, etc. Even if it is reheated by, it can be easily opened without fusing with the heat of steam or oil generated from food. It is highly recyclable and can be recycled using existing waste paper recycling equipment. Furthermore, while using an aqueous coating agent, it is also excellent in curling resistance. In addition, by forming the coat layer by flexographic printing, it is possible to print the pattern and form the coat layer without moving to another line or place. Compared with conventional polyethylene laminated paper, the equipment Economics such as reduction of investment and maintenance costs, shortening of delivery time, reduction of transportation cost, and reduction of transportation distance can reduce the burden on the environment such as CO ₂ . Currently, there is no clear hygiene standard for paper in Japan's Food Sanitation Law, so all components are based on the FDA 176.170 positive list (paper, paperboard ingredients-for food contact with oil, moisture) More safe food wrapping paper can be provided.

The food wrapping paper of the present invention is formed from one or more (meth) acrylate monomers and one or more vinyl monomers, and has a glass transition point of −10 ° C. to 50 ° C. It has a coating layer formed by coating and drying an aqueous varnish containing an acid-containing copolymer as a main component and containing a filler on paper weighing 19 to 700 g / m ² by flexographic printing.

Examples of the (meth) acrylate monomer constituting the acid-containing copolymer include butyl acrylate (BA), ethyl acrylate (EA), ethyl methacrylate (EMA), methyl methacrylate (MMA), N-propyl methacrylate, and glycidyl methacrylate (GMA). N-hexyl methacrylate (HMA), 2-ethylhexyl acrylate, methacrylic acid (MAA) and the like. Examples of vinyl monomers constituting the acid-containing copolymer include acrylic acid (AA), fumaric acid, itaconic acid, methyl. Examples include acrylate (MA), acrylonitrile, butadiene, styrene, vinyl acetate, vinyl chloride, vinylidene chloride, and the like.

The acid-containing copolymer used in the present invention is one kind selected from butyl acrylate (BA), ethyl acrylate (EA), ethyl methacrylate (EMA), methyl acrylate (MA), methyl methacrylate (MMA), and N-propyl methacrylate. The above monomers are contained so as to be 50% by weight or more of the total monomers constituting the acid-containing copolymer, and acrylic acid (AA), fumaric acid, glycidyl methacrylate (GMA), N-hexyl methacrylate (HMA), itaconic acid, One or more kinds of monomers selected from methacrylic acid (MAA) are contained so that the amount of each monomer is 5% by weight or less of the total monomers constituting the acid-containing copolymer, and acrylonitrile, butadiene, 2-ethylhexyl acrylate, styrene, vinyl acetate It is a breathable polymer that contains at least one monomer selected from the group consisting of vinyl chloride and vinylidene chloride in an amount of 50% by weight or less of the total monomer constituting the acid-containing copolymer. Moisture permeability, water resistance, oil resistance, and release properties are effectively expressed, which is preferable.

In the present invention, the glass transition point of the acid-containing copolymer needs to be −10 ° C. to 50 ° C. By configuring the acid-containing copolymer so that the glass transition point is −10 ° C. to 50 ° C., water resistance, oil resistance, release essential for food packaging while maintaining the breathability and moisture permeability inherent in paper It also has sex. Furthermore, even if reheating is performed using a microwave oven or the like, it can be easily opened without being fused by the heat of steam or oil generated from food.

The method for producing the acid-containing copolymer is not particularly limited, and a general polymerization method such as emulsion polymerization can be used.

In the present invention, the blending ratio of the acid-containing copolymer contained in the aqueous varnish forming the coat layer is preferably 10% by weight or more based on the entire aqueous varnish at the time of coating. When it is less than 10% by weight with respect to the entire aqueous varnish at the time of coating, the water resistance and oil resistance of the food packaging paper are likely to be lowered.

In the present invention, the aqueous varnish forming the coating layer contains a filler. Examples of the filler include calcium carbonate, talc, kaolin, mica, aluminum hydroxide, barium sulfate, calcium silicate, calcium sulfate, silica, zinc carbonate, zinc oxide, and titanium oxide. , One or more fillers selected from kaolin and mica are preferred. By containing a filler, the problem of curling on the coating side when a conventional aqueous coating agent is applied is solved, and even if a coating layer is formed with an aqueous varnish, the curling resistance is excellent. Moreover, the release property of food and the anti-blocking property when forming a coat layer are also improved.

In the present invention, the proportion of the filler contained in the aqueous varnish forming the coating layer is preferably 5 to 50% by weight with respect to the entire aqueous varnish at the time of coating. When the amount is less than 5% by weight with respect to the entire aqueous varnish at the time of coating, the curl resistance tends to decrease, and when it exceeds 50% by weight, the viscosity of the aqueous varnish increases and the flexographic printability tends to decrease.

In the present invention, the aqueous varnish forming the coating layer preferably contains a wax. By containing a wax, water resistance and oil resistance are improved. As waxes, plant waxes (wood wax, carnauba wax), animal waxes (bee wax, lanolin), petroleum wax (paraffin wax, microcrystalline wax, petrolatum), polyolefin wax (polyethylene wax, polypropylene wax), polyamide wax , Silicon wax, fluorine wax, ethylene acrylic acid wax and the like.

In the present invention, the aqueous varnish forming the coating layer preferably contains an antifoaming agent. By containing an antifoaming agent, the coating suitability when the coating layer is applied by the flexographic printing method is improved. Examples of the antifoaming agent include hydrophobic silica-based, metal soap-based, amide-based, silicon-based, polyether-based, mineral oil-based, wax-based, acrylic-based, and acetylenic diol-based antifoaming agents.

In the present invention, the aqueous varnish forming the coating layer may contain a dispersant. By containing a dispersing agent, the coating suitability at the time of coating a coat layer by a flexographic printing method improves. Dispersants include surfactants (anionic, nonionic, cationic), polycarboxylic acids, naphthalene condensation, aliphatic alcohol sulfates, polyesters, polyethers, vinyl polymers, acetylenic diols, Examples thereof include polyaminoamide-based dispersants.

In the present invention, the aqueous varnish forming the coating layer may contain a leveling agent. By containing the leveling agent, the coating suitability when the coating layer is applied by the flexographic printing method is improved. Examples of the leveling agent include surfactant-based (anionic, nonionic, and cationic), silicon-based, fluorine-based, vinyl polymer-based, alcohol alkoxylate-based, and acetylenic diol-based leveling agents.

In the present invention, the blending ratios of the wax, antifoaming agent, dispersant, and leveling agent contained in the aqueous varnish forming the coating layer are appropriately set according to the desired properties of the coating layer. The wax is preferably 40% by weight or less based on the entire aqueous varnish during coating. If the wax exceeds 40% by weight with respect to the entire aqueous varnish at the time of coating, the air permeability tends to decrease. The antifoaming agent is preferably 3% by weight or less based on the entire aqueous varnish during coating. If the antifoaming agent exceeds 3% by weight with respect to the entire aqueous varnish during coating, pinholes (extraction) are likely to occur during coating. The leveling agent or dispersant is preferably 3% by weight or less based on the entire aqueous varnish during coating. If the leveling agent or dispersant exceeds 3% by weight with respect to the entire aqueous varnish at the time of coating, the water resistance and oil resistance tend to be lowered.

In the present invention, to the aqueous varnish, a thickener, a defoaming agent, a surface conditioner, a preservative, a pigment, a lubricant, a tackifier, a wetting agent, a water-proofing agent, a crosslinking agent, and the like are added as necessary. You may contain an agent in the range which does not inhibit the effect | action of this invention.

In the present invention, the constituent components of the aqueous varnish are used as a varnish after being dissolved and dispersed in a solvent such as water or water / ethanol = 10/0 to 5/5.

The paper used as a base material for the food wrapping paper of the present invention must have a basis weight of 19 to 700 g / m ² . If the basis weight is less than 19 g / m ² , paper breakage is likely to occur during papermaking and printing (formation of a coat layer), and it is difficult to produce stable food packaging paper. Further, when the food wrapping paper of the present invention is used for a hamburger wrap, the paper preferably has a basis weight of 19 to 40 g / m ² . When used for a hamburger wrap, if a paper having a weight exceeding 40 g / m ² is used, problems such as paper return when the hamburger is packaged and a decrease in texture are likely to occur. When the food wrapping paper of the present invention is used as a material such as a carton, a paperboard of 200 to 700 g / m ² is suitable. When the weight is less than 200 g / m ^2, the rigidity after box making is weak, and when it exceeds 700 g / m ² , the moldability is remarkably lowered. The structure of the paper used as the substrate is not particularly limited, and paper normally used for food packaging paper can be used. Since the food wrapping paper of the present invention is paper used for food, it is necessary to use paper that satisfies the standards of the Food Sanitation Law. Specifically, the PCB content in the material is 5 ppm or less (Cyclic erosion No. 442), there is no elution of fluorescent substances (Cyclic erosion No. 244), and the elution amount of heavy metals (as lead) is 1 ppm or less. It is.

In the present invention, it is safer that all the constituents are described in the positive list of FDA 176.170, and further, the FDA usage conditions (food type, temperature limit) are not limited. A high food packaging paper can be provided, which is preferable.

In the present invention, the coat layer is formed by applying and drying the aqueous varnish by a flexographic printing method. By forming the coat layer by flexographic printing method, if you have a flexographic printing device, you can print the pattern and form the coat layer without moving to another line or place like conventional polyethylene laminated paper It can be carried out. Furthermore, if there is an equipment that performs reversal and simultaneous double-sided flexographic printing, it is possible to simultaneously form a pattern and a coat layer in 1 pass. Therefore, it is possible to use conventional flexographic printing equipment and reduce costs such as capital investment, maintenance and management costs, shortened delivery time, and transportation costs compared to polyethylene laminated paper that requires laminating equipment. In addition, since the transport distance is reduced, the generation of CO _{2 and the} like is reduced, and the burden on the environment can be reduced.

In the present invention, the coating and drying conditions of the coating layer by the flexographic printing method can be appropriately set depending on the components of the aqueous varnish and the like, but the dry thickness of the coating layer is preferably 3 to 15 g / m ² . When the dry thickness is less than 3 g / m ² , oil resistance and water resistance are remarkably lowered. ^{On the other hand} , if it exceeds 15 g / m ² , in terms of function, problems such as air permeability, reduced paper texture, and flexographic printing suitability such as wrinkles on the paper and inability to coat uniformly are likely to occur. In addition, a coating layer may apply by one application | coating of aqueous varnish, and may apply it several times. The coat layer may be formed on only one side of the paper or on both sides. A pattern or the like may be printed on the surface of the paper. Since the food wrapping paper of the present invention forms the coat layer by the flexographic printing method, as described above, it is more advantageous when there is pattern printing. Therefore, the figure side printing is performed by the flexographic printing method. preferable. As the pattern printing ink, those generally used can be used.

Example 1
(Synthesis of acid-containing copolymer A)
A sealed pressure reactor equipped with a pressure gauge, a thermometer, a stirrer, a nitrogen gas inlet tube and two dropping tanks was added to 120 parts by weight of deionized water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfone. 0.02 part by weight of tetrasodium salt of succinate, 12 parts by weight of a polymer having a monomer component of styrene: acrylic acid: methacrylic acid = 2: 1: 1 (weight ratio), and 2 parts by weight of 25% by weight aqueous ammonia are charged. And dissolved under stirring at 85 ° C.
The dropping tank 1 was charged with 20 parts by weight of ethyl acrylate, 54 parts by weight of ethyl methacrylate, and 14 parts by weight of 2-ethylhexyl acrylate, and dropped into the reaction tank over 3 hours, 30 parts by weight of water in the dropping tank 2 and 0. 2 parts by weight of the dissolved material was charged and dropped into the reaction vessel over 4 hours. During the polymerization, the reactor was adjusted to a temperature of 85 ° C.
Thus, an acid-containing copolymer A having Tg = 32 ° C. was obtained, and its solid content was about 40% by weight.

(Adjustment of aqueous varnish A)
Using the acid-containing copolymer A obtained by the above method, an aqueous varnish A having the following formulation was prepared (unit: parts by weight).
Talc for food additives: 10 (average particle size: 8 μm)
Acid-containing copolymer A: 80
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 8.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare aqueous varnish A.

(Preparation of food packaging paper No. 1)
The aqueous varnish A was diluted with water until Zan Cup # 3/25 sec. Manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. by flexographic printing using a flexo printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Example 2
(Synthesis of acid-containing copolymer B)
A sealed pressure reactor equipped with a pressure gauge, a thermometer, a stirrer, a nitrogen gas inlet tube and two dropping tanks was added to 120 parts by weight of deionized water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfone. 0.02 part by weight of tetrasodium salt of succinate, 12 parts by weight of a polymer having a monomer component of styrene: acrylic acid: methacrylic acid = 2: 1: 1 (weight ratio), and 2 parts by weight of 25% by weight aqueous ammonia are charged. And dissolved under stirring at 85 ° C.
A dropping tank 1 was charged with 20 parts by weight of butyl acrylate, 36 parts by weight of ethyl methacrylate, and 34 parts by weight of 2-ethylhexyl acrylate, and dropped into the reaction tank over 3 hours, and 30 parts by weight of water and 0. 2 parts by weight of the dissolved material was charged and dropped into the reaction vessel over 4 hours. During the polymerization, the reactor was adjusted to a temperature of 85 ° C.
Thus, an acid-containing copolymer B having a Tg of −3 ° C. was obtained, and its solid content was about 40% by weight.

(Adjustment of aqueous varnish B)
Using the acid-containing copolymer B obtained by the above method, an aqueous varnish B having the following formulation was prepared (unit: parts by weight).
Talc for food additives: 20 (average particle size: 8 μm)
Acid-containing copolymer B: 60
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 18.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare aqueous varnish B.

(Preparation of food wrapping paper No. 2)
The aqueous varnish B was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. by flexographic printing using a flexo printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Example 3
(Synthesis of acid-containing copolymer C)
A sealed pressure reactor equipped with a pressure gauge, a thermometer, a stirrer, a nitrogen gas inlet tube and two dropping tanks was added to 120 parts by weight of deionized water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfone. 0.02 part by weight of tetrasodium salt of succinate, 12 parts by weight of a polymer having a monomer component of styrene: acrylic acid: methacrylic acid = 2: 1: 1 (weight ratio), and 2 parts by weight of 25% by weight aqueous ammonia are charged. And dissolved under stirring at 85 ° C.
The dropping tank 1 was charged with 34 parts by weight of ethyl acrylate, 50 parts by weight of ethyl methacrylate and 6 parts by weight of styrene, and dropped into the reaction tank over 3 hours, and 30 parts by weight of water and 0.2 part by weight of ammonium peroxodisulfate were added to the dropping tank 2. The lysate was charged and dropped into the reaction vessel over 4 hours. During the polymerization, the reactor was adjusted to a temperature of 85 ° C.
In this way, an acid-containing copolymer C having a Tg of 44 ° C. was obtained, and its solid content was about 40% by weight.

(Adjustment of aqueous varnish C)
Using the acid-containing copolymer C obtained by the above method, an aqueous varnish C having the following formulation was prepared (unit: parts by weight).
Talc for food additives: 8 (average particle size: 8 μm)
Acid-containing copolymer C: 82
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 8.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare aqueous varnish C.

(Creation of food wrapping paper No. 3)
The water-based varnish C was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and the flexographic printing method using a 400 wire / in ceramic anilox roll was used to produce 21 g / The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Example 4
(Adjustment of aqueous varnish D)
A commercially available polymer (trade name: PDX-7326 BASF Co., Ltd., glass transition point: 9 ° C.) was used as the acid-containing copolymer to prepare aqueous varnish D according to the following formulation (unit: parts by weight).
Talc for food additives: 20 (average particle size: 8 μm)
PDX-7326: 60 (Styrene acrylic polymer BASF)
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 18.4
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare an aqueous varnish D.

(Preparation of food wrapping paper No. 4)
The aqueous varnish D was diluted with water until Zahn Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co. The coating was applied inline three times to an m ² thin paper and dried to form a coat layer having a dry thickness of 5.5 to 6.0 g / m ² .

Example 5
(Preparation of food wrapping paper No. 5)
Aqueous varnish A prepared in Example 1 was diluted with water until Zan Cup # 3/25 seconds made by Koiso Co., Ltd., first 400 lines / in, second 235 lines / in, third 235 lines / in Using a flexographic printing machine using ceramic anilox rolls with different coating amounts, the inline coating was applied three times on 21 g / m ² thin paper manufactured by Oji Paper Co., Ltd. by a flexographic printing method, dried, and the dry thickness was 10.0 to 10. A coat layer of 5 g / m ² was formed.

Example 6
(Preparation of food wrapping paper No. 6)
Aqueous varnish A prepared in Example 1 was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouai Co., Ltd., and flexographic printing using a flexographic printing machine using a 235 wire / in ceramic anilox roll. The 21 g / m ² thin paper made by Oji Paper Co., Ltd. was coated twice inline on the side that would be the food contact surface and dried. Furthermore, on the opposite side of the paper (the side that does not contact the food), the flexographic printing method using a 400-line / in ceramic anilox roll is applied once inline by flexographic printing, and dried. A coat layer having a total dry thickness of 10.0 to 10.5 g / m ² was formed.

Example 7
(Adjustment of aqueous varnish E)
Using the acid-containing copolymer B obtained in Example 2, an aqueous varnish E having the following formulation was prepared (unit: parts by weight).
Hydrous kaolin: 20 (average particle size: 0.4 μm)
Acid-containing copolymer B: 60
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 18.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare an aqueous varnish E.

(Creation of food wrapping paper No. 7)
The aqueous varnish E was diluted with water until Zahn Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. by flexographic printing using a flexographic printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Example 8
(Adjustment of aqueous varnish F)
Aqueous varnish F having the following formulation was prepared using the acid-containing copolymer A obtained in Example 1 (unit: parts by weight).
Talc for food additives: 10 (average particle size: 8 μm)
Acid-containing copolymer A: 80
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
SN Dispersant 5040: 0.5
(Polycarboxylic acid-based dispersant San Nopco)
Water: 8.15
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare an aqueous varnish F.

(Creation of food wrapping paper No. 8)
The aqueous varnish F was diluted with water until Zahn Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. produced by flexographic printing using a flexo printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Reference example 1
(Production of food packaging paper No. 9)
Aqueous varnish A prepared in Example 1 was diluted with water until Zan Cup # 3/25 seconds manufactured by Kouaisha Co., Ltd., and was printed by flexographic printing using a 400 line / in ceramic anilox roll. It was applied once to a 21 g / m ² thin paper manufactured by Paper Industries Co., Ltd. and dried to form a coat layer having a dry thickness of 1.2 to 1.5 g / m ² .

Reference example 2
(Preparation of food wrapping paper No. 10)
Aqueous varnish A prepared in Example 1 was diluted with water until Zan Cup # 3/25 seconds made by Koiso Co., Ltd., and was printed by flexographic printing using a flexographic printing machine using a 200 wire / in ceramic anilox roll. In-line coating was performed three times on 21 g / m ² thin paper manufactured by Paper Industries Co., Ltd. and dried to form a coating layer having a dry thickness of 16.0 to 16.5 g / m ² .

Reference example 3
(Adjustment of aqueous varnish J)
Aqueous varnish J was prepared by the following formulation using a commercially available polymer (trade name: PDX-7341 BASF Co., Ltd., glass transition point: 15 ° C.) as the acid-containing copolymer (unit: parts by weight). Note that PDX-7341 has restrictions on the use conditions (food type, use temperature) of FDA 176.170.
Talc for food additives: 20 (average particle size: 8 μm)
PDX-7341: 60 (Styrene acrylic polymer BASF)
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 18.4
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare an aqueous varnish J.

(Preparation of food packaging paper No. 11)
The water-based varnish J was diluted with water until Zan Cup # 3/25 sec. Manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Comparative Example 1
(Synthesis of acid-containing copolymer E)
A sealed pressure reactor equipped with a pressure gauge, a thermometer, a stirrer, a nitrogen gas inlet tube and two dropping tanks was added to 120 parts by weight of deionized water, N- (1,2-dicarboxyethyl) -N-octadecyl sulfone. 0.02 part by weight of tetrasodium salt of succinate, 12 parts by weight of a polymer having a monomer component of styrene: acrylic acid: methacrylic acid = 2: 1: 1 (weight ratio), and 2 parts by weight of 25% by weight aqueous ammonia are charged. And dissolved under stirring at 85 ° C.
The dropping tank 1 is charged with 10 parts by weight of ethyl acrylate, 50 parts by weight of ethyl methacrylate, and 28 parts by weight of styrene, and dropped into the reaction tank over 3 hours, and 30 parts by weight of water and 0.2 part by weight of ammonium peroxodisulfate are added to the dropping tank 2. Was dissolved in the reaction vessel over 4 hours. During the polymerization, the reaction layer was adjusted to a temperature of 85 ° C.
Thus, an acid-containing copolymer E having Tg = 71 ° C. was obtained, and the solid content thereof was about 40% by weight.

(Adjustment of aqueous varnish G)
Using the acid-containing copolymer E obtained by the above method, an aqueous varnish G having the following formulation was prepared (unit: parts by weight).
Talc for food additives: 5 (Average particle size: 8μm)
Acid-containing copolymer E: 85
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 8.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare an aqueous varnish G.

(Creation of food wrapping paper No. 12)
The water-based varnish G was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. was manufactured by flexographic printing using a flexographic printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Comparative Example 2
(Adjustment of aqueous varnish H)
A commercially available polymer (trade name: PDX-7326 BASF Co., Ltd., glass transition point: 9 ° C.) was used as the acid-containing copolymer to prepare aqueous varnish H with the following formulation.
PDX-7326: 92 (Styrene acrylic polymer BASF)
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 6.4
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare aqueous varnish H.

(Creation of food packaging paper No. 13)
The aqueous varnish H was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. by flexographic printing using a flexo printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Comparative Example 3
(Adjustment of aqueous varnish I)
Using the acid-containing copolymer A obtained in Example 1, an aqueous varnish I having the following formulation was prepared (unit: parts by weight).
Acid-containing copolymer A: 92
Paraffin wax: 1
Dehydran 1513: 0.3 (silicon-based antifoaming agent Cognis Co., Ltd.)
1,2-benzisothiazolin-3-one: 0.05 (preservative)
Surfinol 420: 0.3
(Acetylene Range All Leveling Agent Air Products)
Water: 6.35
Total: A solution composed of 100 parts by weight or more was dispersed with a sand mill to prepare aqueous varnish I.

(Preparation of food wrapping paper No. 14)
The aqueous varnish I was diluted with water until Zan Cup # 3/25 seconds manufactured by Rouensha Co., Ltd., and 21 g / Oji Paper Co., Ltd. was manufactured by flexographic printing using a flexographic printing machine using a 400 wire / in ceramic anilox roll. The coating was applied in-line three times to m ² thin paper and dried to form a coating layer having a dry thickness of 5.5 to 6.0 g / m ² .

Comparative Example 4
(Preparation of food packaging paper No. 15)
Aqueous varnish A prepared in Example 1 was diluted with water / ethanol = 1/1 solvent until Zahn Cup # 3/20 seconds made by Koiso Co., Ltd., 175 lines / in, ∠0, stylus 120 °, helio plate With a gravure printing machine using a lacquer, it is applied twice to 21 g / m ² thin paper manufactured by Oji Paper Co., Ltd. by gravure printing and dried to form a coat layer with a dry thickness of 5.0 to 5.5 g / m ² did.

Comparative Example 5
(Food wrapping paper No. 16)
As a polyethylene laminated paper, McDonald's “Fillefish” wrapping paper, in which polyethylene having a film thickness of about 10 μm is laminated on 21 g / m ² thin paper, is used for food wrapping paper No.1. It was set to 16.

Comparative Example 6
(Food wrapping paper No. 17)
As a wax paper, McDonald's “Mc Crispy” wrapping paper, in which a wax having a thickness of about 10 μm is applied to a 21 g / m ² thin paper, is used for food wrapping paper No.1. It was set to 17.

Test method (1) Moisture penetration test (water resistance)
A white cotton cloth moistened with 100% water is placed on the surface of the coat layer of the wrapping paper of Examples, Reference Examples, and Comparative Examples, and the degree of water soaking into the paper after standing for 5 minutes is visually determined.
Evaluation criteria: Excellent 10 ← → Inferior

(2) Oil penetration test (oil resistance)
Salad oil is applied to the coat layer surface of the wrapping paper of Examples, Reference Examples, and Comparative Examples, and the degree of soaking of the salad oil after standing for about 30 minutes is visually determined.
Evaluation criteria: Excellent 10 ← → Inferior

(3) Resistance test (anti-hamburger test)
[1] Vans Release Test The wrapping papers of Examples, Reference Examples, and Comparative Examples are cut to a width of 25 × 29 cm to obtain test samples.
↓
After cooking, McDonald's “Fillefish” is packed with the above test sample and allowed to stand for about 1 hour.
↓
Unpack and sensory evaluate the releasability between the test sample and the "Filleofisch" buns.
Evaluation criteria: Excellent 10 ← → Inferior

[2] Permeability evaluation of water and oil (water resistance / oil resistance)
The wrapping papers of Examples, Reference Examples, and Comparative Examples are cut to a width of 25 × 29 cm and used as test samples.
↓
The McDonald's “Mac pork” immediately after cooking is packaged with the above test sample and allowed to stand for about 1 hour.
↓
Heat in 1700W microwave for 1 minute.
↓
After 5 minutes of heating, the degree of penetration of water and oil into the test sample is visually determined.
Evaluation criteria: Excellent 10 ← → Inferior

[3] Evaluation with solid buns Unpack the package after 5 minutes of heating in the microwave oven used in the above [2], and determine the degree of solid buns used on the “Mac pork” visually and by touch.
Evaluation criteria: Excellent 10 ← → Inferior

(4) Curl angle measurement (curling resistance)
Measuring method: JAPAN TAPPI Standard No. 15-3 Paper-Curl test method-Part 3: Curl angle measurement method-Temperature and humidity: 25 ° C, 60%
・ Humidity adjustment time: 4 hours ・ Measured with the horizontal direction of the wrapping paper as the curl axis and the coat layer surface on the outside.

(5) Breathability measurement method:
JIS P8117 - air permeability of the paper and board testing method - in a sample of the area of the compliant 645 mm ² time required to pass air 100 ml (sec)
* The lower the value, the better the air permeability

(6) Method for measuring moisture permeability:
JAPAN TAPPI Standard No. 7-Conforms to paper and paperboard moisture permeability test method * The higher the value, the higher the moisture permeability

(7) FDA evaluation and evaluation: ○: No limitation is imposed by restrictions on the use conditions of FDA 176.170 (food type, use temperature), and it is suitable as a paper coating agent used for food packaging.
Evaluation: Δ ····· FDA 176.170 limits the use conditions (food type, use temperature), and usable foods are limited. In particular, it is not suitable as a fast food wrapping paper such as a hamburger.

Tables 1 to 5 show the test results of the above tests for the wrapping papers of Examples, Reference Examples, and Comparative Examples.

* 1: Measurement not possible (over 1000 seconds)
* 2: “Wrinkles” entered the paper during coating, making it difficult to apply evenly.

* 3: After coating with an aqueous varnish, it is wound into a roll and stored at room temperature (20-30 ° C) for 7 days. Blocking occurs between the varnish and the back of the paper.

* 4: Spotted pattern is uneven.

The food wrapping paper of the present invention has excellent water resistance, oil resistance, curl resistance, and release property while maintaining the breathability and moisture permeability of the paper, and can be reheated by a microwave oven or the like. It can be easily opened without fusing with the heat of steam or oil generated from food, and is suitable for food packaging. In particular, fast food, especially hamburger wrapping paper, is important for water resistance, oil resistance, and release of buns, and the food wrapping paper of the present invention can be suitably used.

Claims

Filler composed mainly of an acid-containing copolymer formed from one or more (meth) acrylate monomers and one or more vinyl monomers and having a glass transition point of −10 ° C. to 50 ° C. Having a coating layer formed by applying and drying a water-based varnish containing a weight of 19 to 700 g / m 2 on a paper by a flexographic printing method, and having air permeability, moisture permeability, water resistance and oil resistance, Food packaging paper characterized by excellent curl resistance and food release properties.
2. The food wrapping paper according to claim 1, wherein the aqueous varnish contains at least one additive selected from a wax, an antifoaming agent, a dispersing agent, and a leveling agent.
The acid-containing copolymer includes at least one monomer selected from butyl acrylate (BA), ethyl acrylate (EA), ethyl methacrylate (EMA), methyl acrylate (MA), methyl methacrylate (MMA), and N-propyl methacrylate. Containing 50% by weight or more of the total monomer constituting the acid-containing copolymer, acrylic acid (AA), fumaric acid, glycidyl methacrylate (GMA), N-hexyl methacrylate (HMA), itaconic acid, methacrylic acid (MAA) One or more monomers selected from the group consisting of acrylonitrile, butadiene, 2-ethylhexyl acrylate, styrene, vinyl acetate, and vinyl chlora 2. A polymer obtained by copolymerizing one or more monomers selected from the group consisting of vinylidene chloride and 50% by weight or less of the total monomers constituting the acid-containing copolymer. Or Food packaging paper according to 2.
The food packaging paper according to any one of claims 1 to 3, wherein the filler is one or more fillers selected from calcium carbonate, talc, kaolin, and mica.
The food packaging paper according to any one of claims 1 to 4, wherein the dry thickness of the coating layer is 3 to 15 g / m 2 .
Any of the constituents described in the positive list of FDA 176.170 and having a composition with no restrictions on FDA usage conditions (food type, temperature limit) Food packaging paper according to claim 1.
The food wrapping paper according to any one of claims 1 to 6, wherein the food wrapping paper is for fast food.