Greaseproof paper and its manufacturing method

Abstract

To provide oil-resistant paper with high oil-resistant performance, in which problems of local penetration of oil are suppressed.SOLUTION: There is provided oil-resistant paper having an oil-resistant layer containing an oil-resistant agent on one or both sides of base paper in which a main component is pulp containing a linear fatty acid having a content of 1,600 ppm or less, wherein at least a part of the oil-resistant agent in the oil-resistant layer permeates into the base paper.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to grease-resistant paper and a method for producing the same, and more particularly to grease-resistant paper with high oil resistance and a method for producing the same. [Background technology]

[0002] Greaseproof paper, which is paper that is resistant to oil, is used as a packaging material for foods that contain oil and fat, such as hamburgers and fried foods, sold at convenience stores and fast food restaurants, and for paper containers such as paper plates. In recent years, greaseproof paper that contains fluorine-based resin as an oil-resistant agent has been widely used (for example, see Patent Document 1).

[0003] However, even if an oil-resistant agent containing a fluorine-based resin as a main component is used, there are cases where the oil penetration into the grease-resistant paper cannot be sufficiently prevented. Specifically, there are cases where the oil penetrates locally into the grease-resistant paper, and there is a demand for an improvement in this respect. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-209590 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above problems, the present invention proposes an greaseproof paper having excellent oil resistance and a manufacturing method thereof. More specifically, the object of the present invention is to provide an greaseproof paper having excellent oil resistance and suppressing the problem of localized oil penetration.

[0006] Other objects and advantages of the present invention will become readily apparent to those skilled in the art by reading the following description. [Means for solving the problem]

[0007] In order to solve the above problems, the greaseproof paper according to the present invention is characterized in that it has an oil-resistant layer containing an oil-resistant agent on one or both sides of a base paper mainly composed of pulp with a linear fatty acid content of 1600 ppm or less, and at least a part of the oil-resistant agent in the oil-resistant layer permeates into the base paper. Furthermore, the manufacturing method of the greaseproof paper according to the present invention is a manufacturing method of the greaseproof paper in which a processing liquid containing an oil-resistant agent is applied to or impregnated into the base paper mainly composed of pulp, and the base paper is characterized in that the linear fatty acid content is 1600 ppm or less. By adopting such a configuration, it is possible to manufacture greaseproof paper with high oil resistance performance in which the problem of localized oil penetration is suppressed.

[0008] In the present invention, the straight-chain fatty acid may have a carbon number selected from the group consisting of 24, 26 and 28, and the content in the base paper may be 1200 ppm or less. If the content is within this range, greaseproof paper with even higher oil resistance can be produced.

[0009] In the present invention, it is preferable that the base paper does not contain a sizing agent. By not containing a sizing agent in the base paper, the oil-proofing agent can easily permeate into the base paper, thereby achieving even higher oil resistance.

[0010] In the present invention, the processing fluid containing the oil-proofing agent may contain a nonionic surfactant. This not only reduces the surface tension of the processing fluid containing the oil-proofing agent, making it easier for the oil-proofing agent to penetrate into the base paper, but also allows the oil-proofing agent and auxiliary agents, which have ionic properties, to be aggregated without causing high oil resistance. Effect of the Invention

[0011] According to the present invention, it is possible to provide an grease-resistant paper having high oil resistance, in which the grease-resistant agent penetrates the base paper widely and evenly, thereby suppressing localized oil penetration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, the present invention will be described in detail with reference to the embodiments, but the present invention is not limited to these descriptions. Various modifications of the embodiments may be made as long as the effects of the present invention are achieved.

[0013] The grease-resistant paper of the present invention is characterized in that it has an oil-resistant layer containing an oil-resistant agent on a base paper mainly composed of pulp, and at least a part of the oil-resistant agent in the oil-resistant layer permeates into the base paper, thereby exhibiting excellent oil resistance. In the present invention, the oil-resistant layer is on one or both sides of the base paper of the grease-resistant paper, but it is preferable that the oil-resistant layer is on both sides. Therefore, the following mainly describes an embodiment of the present invention having an oil-resistant layer on both sides, but in the present invention, the grease-resistant paper having an oil-resistant layer on one side of the base paper is also intended to be the grease-resistant paper of the present invention. The manufacturing method of the grease-resistant paper of the present invention may be any method, but in one embodiment of the manufacturing method of the grease-resistant paper, a processing liquid containing an oil-resistant agent is applied to or impregnated into the base paper mainly composed of pulp. Thereby, an oil-resistant layer can be formed on the grease-resistant paper of the present invention, where the oil-resistant layer is not only present in a layer on the surface of the base paper, but also a part of its components, particularly at least a part of the oil-resistant agent, uniformly and evenly permeates into the base paper. Thereby, it is possible to provide an grease-resistant paper with high oil resistance performance in which local oil penetration is suppressed.

[0014] Here, the main component refers to the component that is the most abundant on a mass basis among the components that make up the base paper, and refers to a component that is contained in 50 mass% or more of the components. In this embodiment, the pulp is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 100 mass% of the components that make up the base paper. As the raw material pulp used for the base paper, softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP) are preferable. Chemical pulps such as hardwood unbleached kraft pulp (LUKP) and softwood unbleached kraft pulp (NUKP), mechanical pulps such as groundwood pulp (GP) and thermomechanical pulp (TMP), and waste paper pulp such as deinked pulp contain lignin, impurities, etc., so it is preferable to use them to a minimum or to use them unused. The pulp is preferably mainly composed of hardwood bleached kraft pulp (LBKP), and the hardwood bleached kraft pulp (LBKP) may be 50% by mass or more of the total pulp. For example, the hardwood bleached kraft pulp (LBKP) may be 50 to 90% by mass, preferably 60 to 80% by mass, for example, 65 to 75% by mass, and the softwood bleached kraft pulp (NBKP) may be 10 to 50% by mass, preferably 20 to 40% by mass, for example, 25 to 35% by mass. In the present invention, for packaging applications, the basis weight is 20 to 100 g / m 2 In this region, there is a concern of breakage, so it is preferable to incorporate NBKP.

[0015] The wood chips used to make the LBKP used here are mainly acacia and eucalyptus. Examples of acacia include Acacia mangium, Acacia auriculformis, Acacia catechu, Acacia decarens, Acacia holoserisia, Acacia leptocarpa, Acacia maydenii, Acacia melanthy, Acacia melanoxylon, Acacia neriphora, Acacia silivestris, Acacia peregrinalis, and hybrids thereof, and it is preferable to use at least one of these tree species. Acacia wood has a low specific gravity, is easy to obtain, and is inexpensive, but contains a lot of straight-chain fatty acids, especially straight-chain fatty acids with carbon numbers selected from the group consisting of 24, 26, and 28. Therefore, in order to reduce the amount of straight-chain fatty acids, it is preferable not to mix a large amount of acacia wood. In the case of Japan, when importing from a relatively nearby country, such as Southeast Asia such as Vietnam or Australia, the distance is short, so the seasoning period is short, and the amount of straight-chain fatty acids is likely to be high.

[0016] Examples of eucalyptus include Eucalyptus camaldrensis, Eucalyptus deglupta, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus maculata, Eucalyptus punctata, Eucalyptus saligna, Eucalyptus telenicornis, Eucalyptus europhylla, Acacia aulacocarpa, and Acacia crassicarpa, and hybrids thereof. Eucalyptus is expensive to obtain, but contains a small amount of straight-chain fatty acids with carbon numbers selected from the group consisting of 24, 26, and 28. In order to reduce the amount of straight-chain fatty acids, it is preferable to incorporate a large amount of eucalyptus. In the method for producing grease-resistant paper of the present invention, the straight-chain fatty acid content in the base paper must be 1600 ppm or less, but the straight-chain fatty acid content can be adjusted by appropriately adjusting the ratio of acacia wood and eucalyptus wood, the place of origin, etc., or by appropriately adjusting the processing process of the pulp raw material. For example, the mass ratio of acacia wood and eucalyptus wood may be 10:90 to 60:40, preferably 20:80 to 50:50.

[0017] The coniferous wood used to make NBKP is not particularly limited, but preferably used are spruce or holly trees, fir trees, pines, cedars, etc. In NBKP obtained from these tree species, the amount of straight-chain fatty acids having carbon numbers selected from the group consisting of 24, 26, and 28 is low, for example, 400 ppm or less.

[0018] In the grease-resistant paper and its manufacturing method of the present invention, the linear fatty acid content in the base paper is 1600 ppm or less. Here, in this specification, ppm is parts per million by mass. The performance required for grease-resistant paper, especially for grease-resistant paper used for packaging materials such as food, is the performance of being resistant to edible oil even when in contact with the oil for a long time. Considering such performance, the grease-resistant paper is required to have little variation in oil resistance even locally over the entire surface of the paper. By making the linear fatty acid content in the base paper as small as 1600 ppm or less, the oil-resistant agent penetrates into the base paper evenly, so that not only the oil-resistant layer but also the oil-resistant agent penetrates into the base paper at a constant rate, thereby obtaining excellent oil resistance. In other words, the oil-resistant agent penetrates not only into the oil-resistant layer on the surface but also into the thickness direction of the paper, thereby obtaining better oil resistance. On the other hand, when the content of linear fatty acids in the base paper is high, some of the hydrophilic pulp fibers become hydrophobic, which results in uneven penetration of the processing liquid containing the oil-resistant agent into the base paper, which is thought to lead to a local decrease in oil resistance on the surface of the grease-resistant paper, that is, local penetration of oil into the grease-resistant paper. Therefore, in the grease-resistant paper of the present invention, the content of linear fatty acids in the base paper is set to 1600 ppm or less. This gives the paper a performance that makes it difficult for oil to penetrate even when it is in contact with edible oil for a long time. By setting the content of linear fatty acids in the base paper to 1600 ppm or less, preferably 1300 ppm or less, uneven penetration of the processing liquid containing the oil-resistant agent into the base paper is suppressed, and local variation in oil resistance of the grease-resistant paper is suppressed. In addition, there are various linear fatty acids, but linear fatty acids with carbon numbers of 24, 26 and 28, which are abundant in acacia wood, have the greatest effect, and it is preferable to reduce them. For example, the content of the linear fatty acid is preferably 1200 ppm or less, and more preferably 1000 ppm or less.

[0019] The raw pulp is made into a pulp slurry having an appropriate degree of beating using a disintegrator and a beater. In the present invention, the Canadian standard freeness (JIS P 8121:1995 Pulp freeness test method) is preferably 150 to 500 ml, more preferably 200 to 350 ml, and even more preferably 250 to 310 ml.

[0020] Pulp slurry adjusted to an appropriate degree of beating is used as a raw material slurry, and paper is made in a papermaking machine to form a base paper for greaseproof paper. Any known papermaking machine can be used as the papermaking machine. That is, paper can be made using a Fourdrinier papermaking machine, a cylinder papermaking machine, a hybrid former, a gap former, or the like. The basis weight of the base paper is not particularly limited, but for packaging purposes, it is 20 to 300 g / m 2 The base paper has a basis weight of 20 to 100 g / m 2 In the range above, single-ply paper is preferable. If multiple layers are used, not only will the basis weight per layer be small, making production difficult, but the paper will also be hard, making it unsuitable for packaging purposes.

[0021] The base paper may contain a sizing agent such as a rosin emulsion sizing agent. However, in the present invention, it is preferable not to contain such a sizing agent in the base paper. By not containing a sizing agent, the processing liquid containing the oil-resistant agent can easily penetrate into the base paper, and as a result, oil resistance is easily achieved. The Stockigt sizing degree of the base paper is preferably 1 second or less, and more preferably 0 seconds. The Stockigt sizing degree is measured according to JIS P8122:04 Paper and paperboard - Method for measuring sizing degree - Stockigt method.

[0022] To the raw material slurry, additives for papermaking such as fillers, wet strength agents, paper strength enhancers, retention aids, coloring dyes, coloring pigments, and aluminum sulfate may be appropriately added within a range that does not impair the intended effect of the present invention. For example, 0.1 to 1 part by mass of aluminum sulfate can be added to 100 parts by mass of pulp. For example, 0.1 to 1 part by mass of amphoteric starch or amphoteric polyacrylamide can be added to 100 parts by mass of pulp as a paper strength enhancer. For example, 0.1 to 1 part by mass of a wet strength agent can be added to 100 parts by mass of pulp. On the other hand, in order to improve the oil resistance performance, the filler, especially the inorganic filler, is preferably 1% by mass or less in the grease-resistant paper, more preferably 0.5% by mass or less. In this specification, the inorganic filler includes ash that is unintentionally mixed in due to the raw material pulp. The lower limit of the content of the inorganic filler contained in the grease-resistant paper is not particularly limited, but may be 0.1% by mass or more in consideration of the unintentionally mixed ash.

[0023] The base paper thus obtained is coated on both sides with a processing liquid containing an oil-resistant agent, or the base paper is impregnated from both sides with a processing liquid containing an oil-resistant agent. The oil-resistant agent used here is not particularly limited, and known oil-resistant agents such as fluorine-based resins and acrylic resins can be used, but fluorine-based resins are preferred. The method of applying or impregnating the processing liquid is also not particularly limited, and it may be an on-machine coater or an off-machine coater. The coating method is also not particularly limited, and it can be applied using a coater such as a two-roll size press, a gate roll size press, or a metering size press, or an impregnation machine attached to a vat containing the processing liquid. Among these, it is preferable to use a two-roll size press on the machine or an impregnation machine off the coater from the viewpoint of production efficiency and oil resistance. The content of the oil-resistant agent in the processing liquid is not particularly limited, but the amount of oil-resistant agent attached to both sides of the base paper is 0.03 to 0.30 g / m in terms of solid content. 2 It is preferable to adjust the thickness so as to be in the range of 0.07 to 0.15 g / m. 2 The range is.

[0024] It is preferable that the processing liquid contains a nonionic surfactant in addition to the oil-resistant agent. The nonionic surfactant not only reduces the surface tension of the solution containing the oil-resistant agent, making it easier for the oil-resistant agent to penetrate into the base paper, but also exerts high oil resistance without causing the ionic oil-resistant agent or auxiliary agent to aggregate. Nonionic surfactants include ester type, ether type, ester-ether type, etc. Ester type includes glycerin fatty acid ester, sorbitan fatty acid ester, and sucrose fatty acid ester. Ether type includes polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, etc. Ester-ether type has both ester bond and ether bond in the molecule. The content of the nonionic surfactant in the processing liquid is not particularly limited, but the amount of nonionic surfactant attached to the base paper on both sides is 0.01 to 0.0.10 g / m in terms of solid content. 2 It is preferable to adjust the thickness so as to be within a range of 0.03 to 0.08 g / m. 2 The range is.

[0025] In addition to the oil-resistant agent and nonionic surfactant, the processing liquid may contain known water-soluble polymers such as starch, oxidized starch, polyvinyl alcohol, and polyacrylamide. Of these, polyvinyl alcohol is preferred because it contributes to oil resistance. Therefore, it is preferable to contain a fluorine-based resin, a nonionic surfactant, and polyvinyl alcohol. The content of polyvinyl alcohol in the processing liquid is not particularly limited, but the amount of polyvinyl alcohol attached to both sides of the base paper is preferably 0.05 to 0.50 g / m2 in terms of solid content. 2 It is preferable to adjust the thickness so as to be in the range of 0.07 to 0.4 g / m. 2 The range is.

[0026] In this embodiment, the base paper after drying may be subjected to a smoothing treatment if necessary. The method of smoothing treatment is not particularly limited, and machine calendar, soft calendar, super calendar, etc. may be used. EXAMPLES

[0027] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" refer to "parts by mass" and "% by mass", respectively, unless otherwise specified. The number of parts added is a value calculated as a solid content.

[0028] <Example 1> 70 parts of LBKP (mass ratio of acacia wood to eucalyptus wood is acacia wood:eucalyptus wood = 40:60) and 30 parts of NBKP were dispersed in water and beaten to 300 ml of Canadian Standard Freeness (CSF) to obtain a pulp slurry. 0.5 parts of aluminum sulfate, 0.4 parts of amphoteric starch (product name: Neotack #110M / manufactured by Nihon Shokuhin Kako Co., Ltd.), 0.2 parts of wet strength agent (product name: WS4030 / manufactured by Seiko PMC Co., Ltd.), and 0.1 parts of amphoteric polyacrylamide (product name: Hermide RB234 / manufactured by Harima Kasei Co., Ltd.) were added to the obtained pulp slurry to obtain a raw material slurry. The obtained raw material slurry was used to make paper on a fourdrinier paper machine to obtain a base paper. The total straight chain fatty acid content of the obtained base paper was 1180 ppm. In addition, the straight chain fatty acid content of carbon numbers 24, 26, and 28 was 910 ppm. The base paper is pressed and dried, then processed with a two-roll size press using a processing solution of 0.2% oil-resistant agent (AG-E060, concentration 20% / AGC), 0.1% nonionic surfactant (Meikasurf-28, solid content 20% / Meisei Chemical Industry Co., Ltd.), and 0.3% polyvinyl alcohol (PVA117 / Kuraray Co., Ltd.) at 0.3 g / m on both sides of the base paper. 2 The paper was then dried in a cylinder dryer and smoothed using a multi-stage calendar to obtain the desired greaseproof paper. 2 It was.

[0029] <Example 2> Grease-resistant paper was obtained in the same manner as in Example 1, except that the mass ratio of acacia wood and eucalyptus wood in the LBKP was changed to acacia wood:eucalyptus wood = 20:80. The total straight-chain fatty acid content in the base paper was 820 ppm. In addition, the straight-chain fatty acid content with carbon numbers of 24, 26, and 28 was 630 ppm.

[0030] <Example 3> Grease-resistant paper was obtained in the same manner as in Example 1, except that the mass ratio of acacia wood and eucalyptus wood in the LBKP was changed to acacia core wood:eucalyptus wood = 60:40. The total linear fatty acid content of the base paper was 1550 ppm. In addition, the linear fatty acid content of carbon numbers 24, 26, and 28 was 1190 ppm.

[0031] <Example 4> Grease-resistant paper was obtained in the same manner as in Example 1, except that 0.1 parts of a rosin emulsion sizing agent (product name: CC-1404 / Seiko PMC Corporation) was further added to the pulp slurry. The total straight-chain fatty acid content in the base paper was 1180 ppm. In addition, the straight-chain fatty acid content with carbon numbers of 24, 26, and 28 was 910 ppm.

[0032] <Example 5> Grease-resistant paper was obtained in the same manner as in Example 1, except that a nonionic surfactant (Meikasurf-28, solid content 20% / manufactured by Meisei Chemical Industry Co., Ltd.) was not added to the pulp slurry. The total straight-chain fatty acid content in the base paper was 1180 ppm. The straight-chain fatty acid content of carbon numbers 24, 26, and 28 was 910 ppm.

[0033] <Comparative Example 1> Grease-resistant paper was obtained in the same manner as in Example 1, except that the mass ratio of acacia wood and eucalyptus wood in the LBKP was changed to acacia wood:eucalyptus wood = 70:30. The total straight-chain fatty acid content in the base paper was 1730 ppm. In addition, the straight-chain fatty acid content of carbon numbers 24, 26, and 28 was 1330 ppm.

[0034] <Comparative Example 2> In Comparative Example 1, the amount of processing liquid applied to the base paper was 0.3 g / m on each side. 2 From 0.5 g / m 2 A greaseproof paper was obtained in the same manner as in Comparative Example 1, except that the content of all straight-chain fatty acids in the base paper was 1730 ppm. In addition, the content of straight-chain fatty acids with carbon numbers of 24, 26, and 28 was 1330 ppm.

[0035] <Oil resistance rating 1> Measurements were performed based on JAPAN TAPPI Paper and Pulp Test Method No. 41:2000 Paper and Paperboard - Oil Repellency Test Method - Kit Method. The test results are shown in Table 1 as kit numbers. This test method involves dropping a test liquid containing castor oil onto the paper and evaluating the penetration 15 seconds later, and is a test that evaluates penetration over a relatively short period of time. Note that this method is a kit method test, and the higher the kit number, the better the oil resistance. In the present invention, it is sufficient for the oil resistance to be a kit number of 5 or more.

[0036] <Oil resistance rating 2> Salad oil was dropped onto the test piece, and the degree of penetration was visually confirmed. The evaluation criteria are as shown below. The salad oil used was Nisshin Salad Oil (manufactured by Nisshin Oillio Group, Ltd.). The test results are shown in Table 1 as salad oil resistance. This test evaluates the penetration of oil after prolonged contact with salad oil, and is a test of long-term oil resistance in comparison with Oil Resistance Evaluation 1. ◎: No penetration even after 3 hours or more. Passed. ○: Penetrated within 1 to 3 hours. Passed. ×: Penetration occurred within 1 hour. Failed.

[0037] <Determination of fatty acid amount> The base paper was methylated with tetramethylammonium hydrate (TMAH) and subjected to GCMS. The analysis conditions were ICP 590°C pyrofoil, heating for 15 seconds, and analysis was performed using a gas chromatograph mass spectrometer GCMS-QP2010 Ultra (Shimadzu Corporation). Tetracosanoic acid (C24) was quantified from the peak areas at retention times of 24.32 minutes, hexacosanoic acid (C26) was quantified from the peak areas at retention times of 25.73 minutes, and octacosanoic acid (C28) was quantified from the calibration curves of each standard substance obtained in advance. Linear fatty acids with other carbon numbers were also quantified in the same manner from the corresponding retention times. The quantitative results are shown in Table 1 along with the content of each pulp.

[0038] [Table 1]

[0039] As shown in Table 1, the greaseproof papers obtained in Examples 1 to 5 exhibited oil resistance over a long period of time and were suitable for use as greaseproof papers. These papers can be used appropriately as packaging papers, for example, as packaging materials for foods containing fats and oils, such as hamburgers and fried foods sold at convenience stores and fast food restaurants, as paper containers such as paper plates, and as greaseproof papers that are resistant to oil, and can be used appropriately for a relatively long period of time. On the other hand, the greaseproof papers obtained in Comparative Examples 1 and 2 had a large amount of linear fatty acids, so that the permeation of the processing liquid was uneven and, as a result, no particularly long-term oil resistance was obtained.

Claims

1. The paper has an oil-resistant layer containing an oil-resistant agent on one or both sides of a base paper mainly composed of pulp having a linear fatty acid content of 1600 ppm or less, This grease-resistant paper is characterized in that the content of bleached hardwood kraft pulp (LBKP) in the total pulp is 50% by mass or more.

2. 2. The oil-resistant paper according to claim 1, wherein at least a part of the oil-resistant agent in the oil-resistant layer permeates into the base paper.

3. 3. The greaseproof paper according to claim 1, wherein the straight-chain fatty acid has a carbon number selected from the group consisting of 24, 26 and 28, and the content of the straight-chain fatty acid in the base paper is 1200 ppm or less.

4. The greaseproof paper according to any one of claims 1 to 3, characterized in that the base paper does not contain a sizing agent.

5. The grease-resistant paper according to any one of claims 1 to 4, characterized in that the processing liquid containing the oil-resistant agent contains a nonionic surfactant.

6. A method for producing grease-resistant paper, comprising coating or impregnating a processing liquid containing an grease-resistant agent onto a base paper whose main component is pulp in which hardwood bleached kraft pulp (LBKP) accounts for 50 mass% or more of the total pulp, wherein the base paper has a straight-chain fatty acid content of 1,600 ppm or less.

7. 7. The method for producing grease-resistant paper according to claim 6, characterized in that the straight-chain fatty acid has a carbon number selected from the group consisting of 24, 26 and 28, and its content in the base paper is 1200 ppm or less.

8. An grease-resistant paper described in any one of claims 1 to 5, in which acacia wood and eucalyptus wood are used as wood chips for bleached hardwood kraft pulp (LBKP), and the mass ratio of acacia wood to eucalyptus wood in the wood chips is 10:90 to 60:

40.

9. The grease-resistant paper according to any one of claims 1 to 5 and 8, wherein the base paper is obtained from a pulp slurry having a beating degree of 200 to 350 ml CSF in Canadian Standard Freeness (JIS P 8121:1995 Test method for pulp freeness).

10. A method for producing grease-resistant paper as described in claim 6 or 7, wherein acacia wood and eucalyptus wood are used as wood chips for bleached hardwood kraft pulp (LBKP), and the mass ratio of acacia wood to eucalyptus wood in the wood chips is 10:90 to 60:

40.

11. A method for producing grease-resistant paper according to any one of claims 6, 7 and 10, comprising beating the pulp to a CSF of 200 to 350 ml according to Canadian Standard Freeness (JIS P 8121:1995 Testing method for pulp freeness) to obtain a pulp slurry, and making paper from the pulp slurry to obtain a base paper.

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