Oil resistant paper and packaging bag

Abstract

To provide oil resistant paper which is environmentally friendly and excellent in oil resistance and heat sealability, and a packaging bag having said oil resistant paper.SOLUTION: An oil-resistant paper according to one embodiment of the present invention is heat-sealable oil-resistant paper, which comprises a paper base material containing an oil-resistant agent and a heat-seal layer, with the paper base material laminated on one or both surfaces of the heat-seal layer, and a smoothness of the surface of the heat-seal layer measured according to JIS-P 8119 (1998) is 9 to 200 seconds.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to oil-resistant paper and packaging bags.

Background Art

[0002] In packaging materials for foods such as prepared foods and fast foods, oil-resistant paper is widely used to prevent the outer surface from being soiled by oil due to the oil content of the packaged contents seeping out to the outside.

[0003] In recent years, with the changes in eating habits, laminated paper laminated with resin films such as polyethylene and polyethylene terephthalate has been used in oil-resistant paper for making bags by heat sealing, such as bags for takeout of prepared foods of fried foods fried with oil and packaging bags for microwave ovens (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in laminated paper laminated with a resin film, the surface on which the resin film is laminated has oil resistance, but there is a possibility that the non-laminated surface, the inside, and the side surface of the paper base material cannot be imparted with oil resistance. Also, when the contents to be packaged have moisture, there is a possibility that water droplets accumulate in the package and adhere to the contents, causing the contents to swell and the quality to deteriorate. Furthermore, since the above laminated paper has a film remaining, it cannot be recycled into waste paper and may lead to marine pollution as microplastics. Therefore, there is a demand for oil-resistant paper that is environmentally friendly, replaces laminated paper, and has excellent oil resistance and heat sealability.

[0006] The present invention has been made based on the above circumstances, and an object thereof is to provide an oil-resistant paper that is environmentally friendly and excellent in oil resistance and heat sealability, and a packaging bag having the oil-resistant paper.

Means for Solving the Problems

[0007] The oil-resistant paper according to an embodiment of the present invention is an oil-resistant paper having heat sealability, and includes a paper base material containing an oil-resistant agent and a heat seal layer, and the paper base material has a heat seal layer laminated on one or both sides, and the smoothness measured in accordance with JIS-P8119 (1998) on the surface of the heat seal layer is 9 seconds or more and 200 seconds or less.

Effects of the Invention

[0008] According to the present invention, it is possible to provide an oil-resistant paper that is environmentally friendly and excellent in oil resistance and heat sealability.

Modes for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Invention] The oil-resistant paper according to an embodiment of the present invention is an oil-resistant paper having heat sealability, and includes a paper base material containing an oil-resistant agent and a heat seal layer, and the paper base material has a heat seal layer laminated on one or both sides, and the smoothness measured in accordance with JIS-P8119 (1998) on the surface of the heat seal layer is 9 seconds or more and 200 seconds or less.

[0010] Since the oil-resistant paper contains an oil-resistant agent in the paper base material, it is excellent in oil resistance also inside and on the side surfaces of the paper base material. Further, since the smoothness on the surface of the heat seal layer is 9 seconds or more and 200 seconds or less, the blocking suppression effect between the heat seal layers can be improved. Therefore, the oil-resistant paper can provide an oil-resistant paper excellent in oil resistance and heat sealability. Further, since the oil-resistant paper does not use a resin film, it is environmentally friendly.

[0011] It is preferable that the oil-resistant paper has a smoothness measured in accordance with JIS-P8119 (1998) on the surface of the paper base material on which the heat-sealing layer is laminated, and the smoothness is 8 seconds or more and 30 seconds or less. By having the smoothness of 8 seconds or more and 30 seconds or less, the blocking suppression effect between the heat-sealing layers can be further improved.

[0012] It is preferable that the heat-sealing layer contains an olefin resin as a main component. By containing an olefin resin as a main component in the heat-sealing layer, the heat-sealing strength can be exhibited not only at normal temperature but also at low temperature.

[0013] It is preferable that the main component of the oil-resistant agent is a fluororesin, an acrylic resin, a synthetic rubber latex, or a combination thereof. By having the main component of the oil-resistant agent as a fluororesin, an acrylic resin, or a synthetic rubber latex, the oil-resistant paper has good oil resistance.

[0014] As the addition amount of the oil-resistant agent, it is preferably 4.0 kg / t or more and 10.0 kg / t or less based on the pulp fibers of the paper base material. By having the addition amount of the oil-resistant agent to the pulp fibers of the paper base material within the above range, the oil resistance and the adhesion between the paper base material and the heat-sealing layer are excellent. "kg / t" represents the addition amount (kg) per ton of the pulp fibers of the paper base material.

[0015] The moisture permeability of the oil-resistant paper conforming to JIS-Z0208 (1976) is 2 · 600 g / m 2 · 24 h or more and 1500 g / m

[0016] · 24 h or less, which is preferable. By having the moisture permeability of the oil-resistant paper within the above range, the moisture of the contents to be packaged is less likely to become water droplets and can maintain an appropriate humidity, so that the quality of the contents can be kept good.

[0017] [Details of Embodiments of the Present Invention] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. Hereinafter, an oil-resistant paper according to an embodiment of the present invention will be described in detail. In addition, the blending amount (dry internal addition amount) of each material blended in the paper base material described below refers to the mass ratio with respect to the dry mass of the pulp of the paper base material, unless otherwise specified. Further, the content rate of each material blended in the composition for forming the heat-sealing layer refers to the dry mass ratio of each material with respect to the total mass of the heat-sealing layer, unless otherwise specified.

[0018] <Oil-resistant paper> The oil-resistant paper includes a paper base material and a heat-sealing layer provided on at least one surface of the paper base material. The heat-sealing layer may have either a single-layer or a multilayer structure.

[0019] [Paper base material] The paper base material is obtained by papermaking a slurry containing raw material pulp. The paper base material may be either single-layer or multilayer. (Raw material pulp) The paper base material preferably consists mainly of raw material pulp. As the raw material pulp constituting the paper base material, for example, virgin pulp, waste paper pulp, a combination of these pulps, etc. can be used.

[0020] Examples of virgin pulp include chemical pulps such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached kraft pulp (NUKP), hardwood semi-bleached kraft pulp (LSBKP), softwood semi-bleached kraft pulp (NSBKP), hardwood sulfite pulp, softwood sulfite pulp, etc.; mechanical pulps (MP) such as stone ground pulp (SGP), pressure stone ground pulp (TGP), chemiground pulp (CGP), groundwood pulp (GP), thermomechanical pulp (TMP), etc., which are produced chemically or mechanically, can be used alone or in combination of a plurality.

[0021] Examples of waste paper pulp include repulped waste paper pulp, deinked waste paper pulp (DIP), and deinked and bleached waste paper pulp produced from, for example, tea waste paper, kraft envelope waste paper, magazine waste paper, newspaper waste paper, leaflet waste paper, office waste paper, cardboard waste paper, high-quality waste paper, Kent waste paper, imitation waste paper, deed waste paper, etc. These can be used alone or in combination.

[0022] (Oil-resistant agent) The oil-resistant agent can be added by using one or more compounds such as fluororesins, starches, cellulose derivatives, gelatin, casein, soy protein, polyvinyl alcohol, polymers or copolymers of polyisoprene, chloroprene, polydienes, polyalkenes, polymers or copolymers of vinyl monomers, synthetic rubber latexes, polyurethane resins, polyester resins, polyamide resins, olefin-maleic anhydride resins, silicone resins, acrylic resins, melamine resins, plant waxes, animal waxes, mineral waxes, petroleum waxes, synthetic hydrocarbon waxes, 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, higher fatty acid amides or esters or ketones or ethers of chlorinated hydrocarbons. Among the above oil-resistant agents, from the perspective of oil resistance, it is preferable to add an oil-resistant agent mainly composed of an acrylic resin, synthetic rubber latex, or fluororesin, and particularly a fluororesin is preferred. The oil-resistant paper has excellent oil resistance with a lower addition amount even inside and on the side surfaces of the paper substrate by adding an oil-resistant agent whose main component is a fluororesin to the paper substrate. It is presumed that the oil-resistant agent whose main component is a fluororesin is affected by the high surface tension of the fluororesin, is easily dispersed in the paper substrate, and can exhibit oil resistance even with a low addition amount.

[0023] Examples of the fluororesin include anionic fluororesin or cationic fluororesin. Examples of commercially available anionic fluororesistant oils include Asahi Guard (registered trademark) AG-E080, AG-E090 manufactured by Asahi Glass Co., Ltd., Unidyne (registered trademark) TG-8111, TG8731 manufactured by Daikin Industries, Ltd., Solvera (registered trademark) PT5060, PT5045 manufactured by Solvay, etc. Examples of commercially available cationic fluororesistant oils include Asahi Guard (registered trademark) AG-E060, AG-E070 manufactured by Asahi Glass Co., Ltd., CAPSTONE (registered trademark) P620, P623 manufactured by DuPont, etc. Among these, anionic fluororesin is preferred from the viewpoint of obtaining oil resistance with a low addition amount.

[0024] As the lower limit of the addition amount of the oil-resistant agent, 4.0 kg / t is preferably relative to the pulp fibers of the paper substrate. As the upper limit of the addition amount of the oil-resistant agent, 10.0 kg / t is preferably relative to the pulp fibers of the paper substrate, and 8.0 kg / t is more preferably. When the addition amount of the oil-resistant agent relative to the pulp fibers of the paper substrate is within the above range, the oil resistance and the adhesion between the paper substrate and the heat-seal layer are excellent.

[0025] (Other Additives) Other additives can be added to the paper substrate as necessary. Examples of the additives include fillers, pigments, sizing agents, coagulants, oil-resistant agents, fluorescent brighteners, sulfuric acid bands, yield improvers, drainage improvers, dry paper strength enhancers, wet paper strength enhancers, coloring dyes, coloring pigments, water resistance agents, etc., which can be used alone or in combination of multiple ones.

[0026] (Paper Making) The paper-making method of the paper substrate can be carried out using a known paper-making machine for the raw material slurry containing the above raw material pulp and additives. If necessary, a calendar process can also be provided.

[0027] [Heat-Seal Layer] The heat-seal layer is formed by coating a heat-seal layer-forming composition on one or both sides of the paper substrate.

[0028] The heat seal layer preferably contains an olefin resin as a main component. Examples of the olefin resin include polyethylene resins and polypropylene resins. Examples of the polyethylene resin include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-vinyl acetate copolymer (EVA), carboxylic acid-modified polyethylene, ionomer, and derivatives thereof, and mixtures thereof. Examples of the polypropylene resin include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, carboxylic acid-modified polypropylene, and derivatives thereof, and mixtures thereof. Among these, an ethylene acrylic acid copolymer is more preferable from the viewpoint of heat sealability in a low temperature region around 100 to 130°C.

[0029] The lower limit of the content of the olefin resin with respect to the total solid content of the heat seal layer is 50.0% by mass, preferably 90.0% by mass. If the content of the olefin resin is less than 50.0% by mass, sufficient heat sealability may not be obtained. On the other hand, the upper limit of the content of the olefin resin is 100.0% by mass, preferably 95.0% by mass.

[0030] (Other Additives) Other additives other than those described above can be blended in the heat seal layer of the present invention. As the other additives, for example, water-soluble polymers, adhesives, inorganic pigments, organic pigments, sizing agents, viscosity modifiers, coloring dyes, coloring pigments, water resistance agents, lubricants, etc. can be used alone or in combination of a plurality.

[0031] [Physical Properties of Greaseproof Paper] (Smoothness) The lower limit of Bekk smoothness measured in accordance with JIS-P8119(1998) on the surface of the heat-sealing layer is 9 seconds, and more preferably 15 seconds. The upper limit of the smoothness is 200 seconds, and more preferably 150 seconds. When the smoothness is below the lower limit, the surface of the oil-resistant paper becomes rough (the contact area becomes small), and the heat-sealing strength may decrease. When the smoothness exceeds the upper limit, the blocking suppression effect of the heat-sealing layer may decrease. When the smoothness of the surface of the heat-sealing layer is 9 seconds or more and 200 seconds or less, the blocking suppression effect between the heat-sealing layers can be improved, and the adhesion of the contents can be prevented.

[0032] Also, the lower limit of the smoothness of the surface of the paper base material on which the heat-sealing layer is laminated is preferably 5 seconds, and more preferably 8 seconds. The upper limit of the smoothness is preferably 180 seconds, and more preferably 30 seconds. When the smoothness is below the lower limit, the surface of the oil-resistant paper becomes rough (there are many voids), and the heat-sealing layer coating liquid penetrates too much into the paper base material, so the heat-sealing strength may decrease. When the smoothness exceeds the upper limit, the blocking suppression effect between the heat-sealing layers may decrease.

[0033] (Oil resistance) The lower limit of the Kit value, which is an index of the oil resistance of the oil-resistant paper, is preferably 5 or more, and more preferably 6 or more. If the Kit value is less than 5, the oil-resistant paper may not function as such. The upper limit of the Kit value of the oil-resistant paper is not particularly limited. Here, the "Kit value" indicates the oil resistance of the surface and cross-section measured under the conditions of 23°C and 50% humidity (Kit value by the Kit method in JAPAN TAPPI No.41 Paper and Paperboard - Oil resistance test method - Kit method), and the higher the numerical value, the higher the oil resistance.

[0034] (Moisture permeability) The moisture permeability of the oil-resistant paper is measured based on Condition B in accordance with JIS-Z0208

[1976] Test method for moisture permeability of moisture-proof packaging materials [Cup method]. When the oil-resistant paper is used after being made into a bag, the lower limit of the moisture permeability is 600 g / m2 · Preferably 24 hours, 900 g / m 2 · More preferably 24 hours. Further, as the upper limit of the moisture permeability, 1500 g / m 2 · Preferably 24 hours, 1200 g / m 2 · More preferably 24 hours. When the moisture permeability is within the above range, while having good oil resistance, the moisture of the packaged contents is less likely to become water droplets, and the quality of the contents can be kept good by maintaining an appropriate humidity.

[0035] According to the oil-resistant paper, an oil-resistant paper excellent in oil resistance and heat sealability can be provided. Further, since the oil-resistant paper has a heat-sealable layer that can be released, it can be recycled, and since no resin film is used, environmental protection can be achieved.

[0036] [Manufacturing method of oil-resistant paper] The manufacturing method of the oil-resistant paper is not particularly limited. For example, it includes a step of papermaking a pulp slurry that is a raw material of the paper base material, a step of producing a composition for forming a heat-sealable layer, and a step of coating the composition for forming a heat-sealable layer on at least one surface of the paper base material.

[0037] In the papermaking step, the raw material slurry containing the above-mentioned raw pulp, oil-resistant agent, and other additives is carried out using a known papermaking machine.

[0038] Next, it is preferable to include a step of drying one side of the paper base material formed in the above papermaking process with a Yankee dryer to form a glossy surface. In this step, the contact surface with the Yankee dryer is formed as the glossy surface. More specifically, the wet paper is pressed against the Yankee dryer with a so-called felt, and the mirror surface of the cylinder surface of the Yankee dryer is copied onto the wet paper to obtain the glossy surface of the single-sided glossy kraft paper. In the drying process with the Yankee dryer, the surface temperature of the dryer is in the range of 100°C or higher and 150°C or lower, and it is pressed against the mirror surface of the Yankee dryer. Also, the non-contact surface with the Yankee dryer is formed as the non-glossy surface. On the non-glossy surface side, the smoothness is adjusted by the material of the felt and the pressure adjustment of the touch roll that presses the felt against the Yankee dryer. Among the above adjustment methods, the method by the pressure adjustment of the touch roll is preferable. As a result, it is possible to widen the front-back difference in smoothness between the glossy surface and the non-glossy surface while maintaining the density of the paper base material. The paper base material having the glossy surface and the non-glossy surface can exhibit a blocking suppression effect by laminating a heat-sealing layer on the non-glossy surface side, and the non-glossy surface side can exhibit an excellent effect on printability. Here, the "glossy surface" refers to a surface having gloss. The "non-glossy surface" refers to a surface having no glossiness.

[0039] As described above, the Bek smoothness of the surface of the paper base material on which the heat-sealing layer is laminated is preferably 8 seconds or more and 30 seconds or less. However, when the greaseproof paper has a heat-sealing layer on one side, the Bek smoothness of the non-glossy surface of the paper base material is adjusted to this range.

[0040] In the heat-sealing layer forming composition generation step, a heat-sealing layer forming composition containing an olefin resin as a main component is generated.

[0041] As the coating method of the composition for forming a heat-sealing layer, a known coating method can be adopted. For example, known coating machines such as a two-roll size press coater, a gate roll coater, a blade metering coater, a rod metering coater, a blade coater, an air knife coater, a roll coater, a brush coater, a kiss coater, a squeeze coater, a curtain coater, a die coater, a bar coater, and a gravure coater can be used.

[0042] As the lower limit of the coating amount (in terms of solid content) on one side of the composition for forming a heat-sealing layer, 2.5 g / m 2 is preferable. If the above coating amount does not meet the above lower limit, the heat-sealing layer may not have sufficient oil resistance and heat-sealing properties. On the other hand, as the upper limit of this coating amount, 3.5 g / m 2 is preferable. If the above coating amount exceeds the above upper limit, the blocking inhibitory property may decrease. In addition, if the coating layer becomes too thick, there is a possibility that coating waste may easily occur in the folding process when processing into a packaging bag.

[0043] For drying the coated composition for forming a heat-sealing layer, a known drying device can be adopted. For example, an infrared drying device, a hot air drying device, a contact-type dryer drying device, etc. can be used.

[0044] The oil-resistant paper thus obtained can utilize various known finishing devices, such as a super calender, a gloss calender, a soft calender, a mat calender, etc., and can also perform appropriate product finishing.

[0045] <Packaging bag> The packaging bag according to another embodiment of the present invention has the oil-resistant paper. Since the packaging bag has the oil-resistant paper, it is excellent in oil resistance and heat-sealing properties. In addition, since the moisture permeability is high, the moisture of the contents is less likely to become water droplets, and the quality of the contents can be kept good to maintain an appropriate humidity.

[0046] <Other embodiments> The present invention is not limited to the above-described embodiments, and can be implemented in various modified and improved forms in addition to the above aspects.

[0047] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0048] [Examples 1 to 9 and Comparative Examples 1 to 2] (Manufacture of paper base material) First, 100% by mass of hardwood kraft pulp [LBKP] was prepared to obtain a pulp slurry. To this pulp slurry, an oil-resistant agent (fluororesin: "Unidine TG8811" manufactured by Daikin Industries, Ltd., synthetic rubber latex: commercially available product, acrylic resin: commercially available product) in the addition amounts shown in Table 1 was added respectively. Further, as other additives, a sizing agent, a retention aid, and a sizing agent were added internally, respectively. The obtained pulp slurry was made into paper using an on-top type fourdrinier paper machine to obtain a paper base material. The basis weight of the paper base material was 50.0 g / m 2 It was.

[0049] (Lamination of heat seal layer) Next, a heat seal layer was formed on one side of the paper base material to obtain an oil-resistant paper having a basis weight of 53.0 g / m 2 The composition of the heat seal layer-forming composition was as shown in Table 1. Further, the following products were used for the olefin resin and the coating amount used in the heat seal layer-forming composition. In addition, "-" in Table 1 below indicates that the corresponding component was not used.

[0050] [Comparative Example 3] A single-layer laminated paper containing a polypropylene film was produced. The base paper was composed of commercially available kraft paper (basis weight 50.0 g / m 2 ) was used. The polypropylene film was produced by extrusion laminating a commercially available polypropylene resin with a pelletizer and laminating it on only one side of the base paper with a thickness of 20 μm.

[0051] Various evaluations of the oil-resistant paper obtained as described above were performed.

[0052] (Smoothness) The Bekk smoothness of the surface of the heat-sealing layer and the surface of the paper base material on which the heat-sealing layer is laminated was measured in accordance with JIS-P8119 (1998).

[0053] (Oil resistance) The kit values of the surface and cross-section of the oil-resistant paper were measured in accordance with JAPAN TAPPI No.41 Paper and Paperboard - Oil Resistance Test Method - Kit Method. When the kit value is 5 or more, the oil resistance is good.

[0054] (Moisture vapor transmission rate) Regarding the moisture vapor transmission rate of the oil-resistant paper of the examples and comparative examples, it was measured based on Condition B in accordance with JIS-Z0208

[1976] Test Method for Moisture Vapor Transmission Rate of Moisture-proof Packaging Materials [Cup Method].[[]END]]

[0055] (Heat seal strength) After processing under the conditions of an atmospheric pressure of 2 atm, a sealer pressure of 2 kg / cm, a sealer time of 1 second, and a seal temperature of 140 °C using a thermal gradient tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the peel strength of the heat-sealed portion was measured using a load cell type tensile tester. The evaluation criteria were as follows in three levels. When the evaluation is ○ and △, the heat seal strength is good. ○: The peel strength is 3.0 N / 25 mm or more. △: The peel strength is 2.0 N / 25 mm or more and less than 3.0 N / 25 mm. ×: The peel strength is less than 2.0 N / 25 mm.

[0056] (Blocking inhibition) For each of the examples and comparative examples, the coated surfaces of the heat-sealing layers of two sheets of oil-resistant paper were brought into close contact with each other, and a reciprocating pressure was applied with a 1 kg crimping roller. Next, after storing under the condition of 40 °C for 1 day, the results of peeling with both hands were evaluated according to the following three-level criteria. When the evaluation is ○ and △, the blocking inhibition is good. ○: There is no blocking, and it peels smoothly. △: Some are blocking, but the peelability is within an acceptable range. ×: Blocking occurs and there are difficulties with peelability.

[0057] The evaluation results of each example and comparative example are shown in Table 1.

[0058]

Table 1

[0059] As shown in Table 1, Examples 1 to 9, which have a paper substrate containing an oil-resistant agent and the smoothness of the surface of the heat-sealing layer is 9 seconds or more and 200 seconds or less, had good oil resistance, heat-sealing strength, and blocking suppression. In particular, Examples 1 to 3, in which the smoothness of the surface of the paper substrate on which the heat-sealing layer is laminated is 8 seconds or more and 30 seconds or less, and the coating amount on one side of the composition for forming the heat-sealing layer is 2.5 g / m 2 or more and 3.5 g / m 2 or less, had excellent heat-sealing strength and blocking suppression. On the other hand, the oil-resistant papers of Comparative Examples 1 and 2, in which the smoothness of the surface of the heat-sealing layer is less than 9 seconds or more than 200 seconds, were inferior in either heat-sealing strength or blocking suppression. Comparative Example 3 is polypropylene (PP) laminated paper, which is not desirable from the perspective of environmental pollution. Also, since the moisture permeability is low, when used as a packaging bag, it is considered that the freshness of the contents may decrease. As described above, it was shown that the oil-resistant paper is excellent in oil resistance and heat-sealability. In addition, the oil-resistant paper has a heat-sealing layer that can be released, enabling recycling, and since it does not use a resin film, environmental conservation can be achieved.

Industrial Applicability

[0060] The oil-resistant paper of the present invention is environmentally friendly, excellent in oil resistance and heat-sealability, and suitable as a packaging material for foods and the like.

Claims

1. A grease-resistant paper having heat sealability, A paper base material containing an oil-resistant agent; Heat seal layer Equipped with The paper base material has a heat seal layer laminated on one or both sides, The grease-resistant paper has a surface smoothness of 9 seconds or more and 200 seconds or less, as measured in accordance with JIS-P8119 (1998).

2. 2. The grease-resistant paper according to claim 1, wherein the smoothness of the surface of the paper base material on which the heat seal layer is laminated, as measured in accordance with JIS-P8119 (1998), is 8 seconds or more and 30 seconds or less.

3. 3. The grease-resistant paper according to claim 1, wherein the heat seal layer contains an olefin resin as a main component.

4. 4. The grease-resistant paper according to claim 1, 2 or 3, wherein the main component of the grease-resistant agent is a fluorine-based resin, an acrylic resin, a synthetic rubber latex or a combination thereof.

5. 5. The grease-resistant paper according to claim 1, wherein the amount of the grease-resistant agent added is 4.0 kg / t or more and 10.0 kg / t or less based on the pulp fibers of the paper base material.

6. Moisture permeability according to JIS-Z0208 (1976) is 600 g / m ２ ・1500g / m for 24 hours or more ２ The grease-resistant paper according to any one of claims 1 to 5, which has a shelf life of 24 hours or less.

7. A packaging bag comprising the greaseproof paper according to any one of claims 1 to 6.

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