An oil-proof label paper, a preparation method and application thereof

Abstract

The application provides an oil-proof label paper and a preparation method and application thereof, and relates to the field of paper processing. The oil-proof label paper comprises a fiber layer, a pre-coating layer and a surface coating layer, the fiber layer is provided with the pre-coating layer on both sides, the surface coating layer is arranged on the pre-coating layer of one side of the fiber layer, and the raw material of the fiber layer comprises wood pulp, kaolin and a functional additive; the coating of the pre-coating layer comprises modified starch and a water-soluble polyacrylate copolymer; and the coating of the surface coating layer comprises an adhesive, kaolin, titanium white and an epoxy resin. The raw materials of the layers are matched with each other and jointly act, so that the label paper forms a multi-stage oil-proof structure from inside to outside, and finally the front and back surfaces of the label paper reach a high oil resistance grade; no fluoride oil-proof agent and film coating are used, the production cost is low, the label paper is degradable and friendly to the environment; meanwhile, the label paper has good smoothness, glossiness and opacity, and is fine in printing, meets different labeling requirements, is suitable for high-speed printing and labeling, and can be used for the packaging label of products containing oil and grease.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paper processing, in particular to an oil-proof label paper and a preparation method and application thereof. BACKGROUND

[0002] Paper labels are increasingly favored by the market due to their good decoration, economy and good environmental retention, and are widely used as an environmentally friendly material for the packaging of various products, such as cigarette packages, wine packages, cosmetics, food, etc., and are also used for laser anti-counterfeiting labels, tags, signs, etc. The labels applied to the packaging of oil and fat products generally use oil-proof label paper to prevent oil from penetrating the label paper and affecting the appearance of the packaging and the readability of the label content.

[0003] Currently, oil-proof labels generally use film labels, such as labels made of polyester or polyethylene film, which can effectively prevent oil and water erosion. In addition, film-coated labels are also commonly used, which are generally coated with polyethylene (PE) particles. Although film labels or film-coated labels can have some oil-proof effect, these types of products have problems such as harmful substance migration, non-biodegradable, and environmental pollution. In the field of packaging paper, a method of coating a coating layer on the surface of the base paper is often used to achieve oil-proof effect. For example, the most commonly used fluorine-containing oil-proof agent can bring good oil-proof effect, but it can easily produce harmful substances such as perfluorooctane sulfonic acid (PFOS) or perfluorooctane amide (FOSE), which can cause health problems, especially in the food packaging field. The risk is higher; polysaccharide oil-proof agent is safe and biodegradable, but high concentration and high viscosity are required to achieve good oil-proof effect, which is not conducive to coating and implementation. The application of the aforementioned oil-proof agent to label paper also introduces the corresponding problems, thereby restricting its use and promotion.

[0004] In addition, as a label paper, in addition to considering the printing and oil-proof effect of the front surface, it is also necessary to ensure that the back surface has good pasteability, i.e. the fiber layer is pasted to the surface of the product packaging by glue, which ensures the firmness of the paste, but does not consider the oil-proof performance of the pasting surface, which may also affect the appearance due to oil penetration.

[0005] Therefore, how to provide an oil-proof label paper that takes into account safety, biodegradability, implementability and good oil resistance has become a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0006] Therefore, the technical problem to be solved by the present application is to overcome the defects of the prior art that the oil-proof label paper and the oil-proof coating cannot simultaneously take into account safety, biodegradability, implementability and good oil resistance, thereby providing a new oil-proof label paper and a preparation method and application thereof.

[0007] To achieve the above object, the present application provides the following technical solutions.

[0008] In the first aspect, the present application provides an oil-proof label paper, comprising a fiber layer, a pre-coating layer and a surface coating layer, the pre-coating layer is arranged on both sides of the fiber layer, and the surface coating layer is arranged on the pre-coating layer of one side of the fiber layer,

[0009] The raw material of the fiber layer comprises the following components in parts by weight: wood pulp 89-94 parts, kaolin 5-10 parts, and functional additives 0.8-1.8 parts;

[0010] The coating of the pre-coating layer comprises the following components in parts by weight: modified starch 50-85 parts and water-soluble polyacrylate copolymer 15-50 parts;

[0011] The coating of the surface coating layer comprises the following components in parts by weight: adhesive 15-30 parts, kaolin 65-85 parts, titanium dioxide 3-10 parts, and epoxy resin 0.5-3 parts.

[0012] Further, the functional additives comprise wet strength agent 0.8-1.5 parts, sizing agent 0.03-0.3 parts, and retention aid 0.001-0.01 parts.

[0013] Further, the sizing agent is alkyl ketene dimer, and the retention aid is polyacrylamide.

[0014] Further, the wood pulp comprises bleached coniferous wood pulp and bleached broad-leaved wood pulp, and the mass ratio of the bleached coniferous wood pulp to the bleached broad-leaved wood pulp is 3-5:5-7.

[0015] The kaolin in the raw material of the fiber layer is superfine kaolin.

[0016] Further, the adhesive is one of styrene acrylic latex, butadiene styrene latex and acrylic latex.

[0017] The kaolin in the coating of the surface coating layer is flaky kaolin.

[0018] The titanium dioxide is rutile titanium dioxide.

[0019] Further, the raw material of the fiber layer comprises the following components in parts by weight: bleached coniferous wood pulp 40 parts, bleached broad-leaved wood pulp 50-55 parts, kaolin 5-10 parts, wet strength agent 1.0 part, alkyl ketene dimer 0.12 part and polyacrylamide 0.007 part.

[0020] The coating of the pre-coating layer comprises the following components in parts by weight: modified starch 70-85 parts and water-soluble polyacrylate copolymer 15-30 parts.

[0021] The coating of the top coating layer comprises the following components by weight: adhesive 15-25 parts, kaolin 70-75 parts, titanium white 3.5-10 parts, and epoxy resin 1-1.5 parts.

[0022] Further, the solid content of the pre-coating layer coating is 5%-15%, and the viscosity is 5-100 cp;

[0023] The solid content of the top coating layer coating is 40%-70%, and the viscosity is 400-1000 cp;

[0024] The single-side coating amount of the pre-coating layer coating is 3-10 g / m 2 ;

[0025] The single-side coating amount of the top coating layer coating is 5-15 g / m 2 .

[0026] Further, the solid content of the pre-coating layer coating is 8%-12%, and the viscosity is 10-55 cp;

[0027] The solid content of the top coating layer coating is 55%-62%, and the viscosity is 500-750 cp;

[0028] The single-side coating amount of the pre-coating layer coating is 3-8 g / m 2 ;

[0029] The single-side coating amount of the top coating layer coating is 8-13 g / m 2 .

[0030] In a second aspect, the application provides a preparation method of the oil-proof label paper, comprising the following steps:

[0031] (1) uniformly mixing the wood pulp, kaolin and functional additives in a proportion, and preparing the fiber layer by using a papermaking process;

[0032] (2) uniformly mixing the modified starch and water-soluble polyacrylate copolymer in a proportion to obtain a pre-coating layer coating, coating the pre-coating layer coating on both sides of the fiber layer, drying, and forming the pre-coating layer;

[0033] (3) uniformly mixing the adhesive, kaolin, titanium white and epoxy resin in a proportion to obtain a top coating layer coating, coating the top coating layer coating on the surface of the pre-coating layer on one side of the fiber layer, drying, and forming the top coating layer;

[0034] (4) finishing the label paper obtained in step (3) to obtain the oil-proof label paper.

[0035] Further, in step (1), when the fiber layer is prepared by using the papermaking process, the speed is 350-700 m / min, and the basis weight is 45-70 g / m2 ;

[0036] Further, in step (2), the pre-coating paint is coated by using a metering rod coating process; and dried by using an infrared hot air drying process, with a temperature of 105-120 DEG C and a vehicle speed of 350-700 m / min.

[0037] Further, in step (3), the top-coating paint is coated by using a doctor blade coating process; and dried by using an infrared hot air drying process, with a temperature of 105-120 DEG C and a vehicle speed of 350-700 m / min.

[0038] Further, in step (4), the label paper is finished by using a super-calendering process, with a vehicle speed of 800 m / min, a line pressure of 70-85 kN / m, and a nip temperature of 95-190 DEG C.

[0039] In a third aspect, the application provides the application of the oil-proof label paper in the packaging of oil-containing products.

[0040] The technical scheme of the application has the following advantages:

[0041] The oil-proof label paper provided by the application is mainly composed of a fiber layer, a pre-coating layer and a top-coating layer, wherein the fiber layer is prepared from wood pulp, kaolin and functional additives.

[0042] The kaolin is added to the fiber layer as an inorganic filler, and the kaolin has the characteristics of high diameter-thickness ratio and high refractive index, and can effectively fill the gaps between the wood pulp fibers, form a compact structure between the fiber network structure, and impart certain barrier properties to the fiber layer.

[0043] The pre-coating layer is arranged on both sides of the fiber layer, and the paint of the pre-coating layer mainly includes modified starch and water-soluble polyacrylate copolymer, which can form a dense and smooth film on the surface of the fiber layer with the interwoven network structure, improve the sealing property of the fiber layer, reduce the porosity, block the penetration of oil and water to the fiber layer, and impart certain oil-proof property to the two sides of the fiber. The pre-coating layer plays multiple roles in the oil-proof label paper: on the one hand, it can ensure certain water-proof and oil-proof property on the back of the fiber layer, and also allow the adhesive to penetrate, providing good adhesion, that is, it can meet the requirements of subsequent labeling on the back of the label, and overcome the problem of aesthetic appearance caused by the penetration of oil on the inside of the label; on the other hand, it provides better flatness and hiding power on the front of the fiber layer, which can effectively prevent the migration of the adhesive in the top-coating paint to the fiber layer, resulting in the reduction of the water-proof and oil-proof property of the top-coating layer, that is, it can provide certain oil-proof property, and enhance the strength and water-proof and oil-proof performance of the top-coating layer.

[0044] The top coating is coated on one side of the pre-coating layer of the fiber layer, and the top coating mainly comprises a binder, kaolin, titanium white and an epoxy resin. The titanium white has good light scattering performance, good whiteness, strong hiding power and high tinting power, can give the label paper good whiteness and opacity, and improve the printing beauty; the sheet structure of the kaolin can make the top coating have good performance of blocking grease and water, and has good glossiness; the titanium white with higher fineness fills the gap between the sheet structure of the kaolin, and the two can make the top coating more dense; the binder is used to combine various raw materials to form a uniform and stable top coating to block grease and water; the resin containing an epoxy group is added to the top coating, can react with the hydrophilic group in the binder, significantly improve the wet friction performance of the coating, and is also beneficial to further improve the water resistance and oil resistance of the label paper.

[0045] The raw materials of the various layers of the label paper cooperate with each other and jointly act, so that the label paper forms a multi-level grease-proof structure from inside to outside, and finally the front oil resistance grade of the label paper reaches more than 10 levels, and the back oil resistance grade also reaches more than 6 levels.

[0046] The grease-proof label paper provided by the application does not use fluoride grease-proof agent and film coating, has low production cost, is overall degradable (the proportion of non-degradable components is very small and can be ignored), is friendly to the environment, has good smoothness, glossiness and opacity, has fine printing, meets different labeling requirements, is suitable for high-speed printing and labeling, has excellent oil resistance, and can be used for packaging labels of grease-containing products, such as edible oil and other grease-containing food. DETAILED DESCRIPTION

[0047] The following examples are provided to better further understand the application, and do not limit the content and protection scope of the application, and do not constitute a limitation on the content and protection scope of the application, and any person who obtains any product the same as or similar to the application under the inspiration of the application or by combining the application with other prior art features falls within the protection scope of the application.

[0048] The raw material information used in the examples is as follows:

[0049] Wet strength agent: polyamide epoxy chloropropane, solid content 12.5%;

[0050] Polyacrylamide: anionic polyacrylamide;

[0051] Water-soluble polyacrylate copolymer: solid content 45%, viscosity <300CP;

[0052] Acrylic latex: solid content ≥48%-51%, viscosity <300CP;

[0053] Epoxy resin: epoxy value 0.59-0.64 equivalents / 100g;

[0054] Ultra-fine kaolin: particle size ≤2.0um ≥92%, whiteness ≥86%;

[0055] Flaky kaolin: particle size ≤2.0um ≥90%, whiteness ≥86, ratio of diameter to thickness is 10-30;

[0056] Rutile titanium white: rutile crystal content in titanium dioxide ≥98% (mass fraction);

[0057] Heavy calcium carbonate: particle size ≤2.0um ≥95%, whiteness ≥92%.

[0058] The weight of each raw material defined in the present application is absolute dry weight.

[0059] If the specific experimental steps or conditions are not specified in the examples, the operation or conditions can be carried out according to the conventional experimental steps described in the literature in the art. The raw materials or instruments used are conventional products that can be obtained by purchase, including but not limited to the raw materials or instruments used in the examples of the present application.

[0060] Example 1

[0061] The present example provides a preparation method of an oil-proof label paper, and the specific steps are as follows:

[0062] (1) The raw materials are weighed according to the following proportions: bleached coniferous pulp 40 parts, bleached broadleaf pulp 55 parts, ultra-fine kaolin 5 parts, wet strength agent 1.0 part, alkyl alkene ketone dimer 0.12 part, and polyacrylamide 0.007 part; mix uniformly, and wet papermaking on a paper machine to form a fiber layer, with a speed of 600 m / min and a fiber layer basis weight of 60 g / m 2 ;

[0063] (2) The raw materials are weighed according to the following proportions: modified starch 80 parts, and water-soluble polyacrylate copolymer 20 parts; the modified starch is cooked into a paste, and then the water-soluble polyacrylate copolymer is added to obtain a pre-coating paint (solid content 8%, viscosity 25 cp); the pre-coating paint is coated on both sides of the fiber layer by using a metering rod coating process, with a single-side coating amount of 5 g / m 2 , and dried by infrared hot air at 105℃, with a speed of 610 m / min, to form a pre-coating layer;

[0064] (3) The raw materials are weighed according to the following proportions: acrylic latex 20 parts, flaky kaolin 75 parts, rutile titanium white 4.2 parts, and epoxy resin 1 part; water is added and uniformly dispersed by a paint dispersion system to obtain a top-coating paint (solid content 60%, viscosity 580 cp); the top-coating paint is coated on the surface of the pre-coating layer on one side of the fiber layer by using a doctor blade coating process, with a coating amount of 10 g / m 2Infrared hot air drying at 120℃, speed 650m / min, to form the surface coating layer;

[0065] (4) The label paper obtained in step (3) is finished by using a multi-roll super calender, speed 800m / min, linear pressure 78kN / m, nip temperature 120℃, to obtain the oil-proof label paper.

[0066] Example 2

[0067] The embodiment provides a preparation method of an oil-proof label paper, and specific steps are as follows:

[0068] (1) The raw materials are weighed according to the following proportions: bleached coniferous pulp 40 parts, bleached broadleaf pulp 55 parts, ultra-fine kaolin 5 parts, wet strength agent 1.0 part, alkyl alkene ketone dimer 0.12 part, and polyacrylamide 0.007 part, which are uniformly mixed to form a fiber layer on a paper machine, speed 600m / min, and the basis weight of the fiber layer is 60g / m 2 ;

[0069] (2) The raw materials are weighed according to the following proportions: modified starch 70 parts and water-soluble polyacrylate copolymer 30 parts, the modified starch is boiled into a paste, then the water-soluble polyacrylate copolymer is added, to obtain a pre-coating paint (solid content 12%, viscosity 55cp), the pre-coating paint is coated on both sides of the fiber layer by using a metering rod coating process, and the single-side coating amount is 8g / m 2 , infrared hot air drying at 105℃, speed 610m / min, to form the pre-coating layer;

[0070] (3) The raw materials are weighed according to the following proportions: acrylic latex 25 parts, flaky kaolin 70 parts, rutile titanium dioxide 3.5 parts and epoxy resin 1.5 parts, water is added and uniformly dispersed through a paint dispersion system, to obtain a surface coating paint (solid content 55%, viscosity 750cp), the surface coating paint is coated on the surface of the pre-coating layer of one side of the fiber layer by using a doctor blade coating process, and the coating amount is 13g / m 2 , infrared hot air drying at 120℃, speed 650m / min, to form the surface coating layer;

[0071] (4) The label paper obtained in step (3) is finished by using a multi-roll super calender, speed 800m / min, linear pressure 78kN / m, nip temperature 120℃, to obtain the oil-proof label paper.

[0072] Example 3

[0073] The embodiment provides a preparation method of an oil-proof label paper, and specific steps are as follows:

[0074] (1) Take the raw materials in the following proportions: 40 parts of bleached coniferous wood pulp, 50 parts of bleached broadleaf wood pulp, 10 parts of ultra-fine kaolin, 1.0 part of wet strength agent, 0.12 part of alkyl alkene ketone dimer, and 0.007 part of polyacrylamide, mix uniformly, wet-form papermaking on a paper machine to form a fiber layer, speed 600 m / min, fiber layer basis weight 60 g / m 2 ;

[0075] (2) Take the raw materials in the following proportions: 85 parts of modified starch, 15 parts of water-soluble polyacrylate copolymer, heat the modified starch into a paste, then add the water-soluble polyacrylate copolymer to obtain a pre-coating coating (solid content 8%, viscosity 10 cp), coat the pre-coating coating on both sides of the fiber layer using a metering rod coating process, single-side coating amount 3 g / m 2 , infrared hot air drying at 105°C, speed 610 m / min, to form a pre-coating layer;

[0076] (3) Take the raw materials in the following proportions: 15 parts of acrylic latex, 75 parts of flaky kaolin, 10 parts of rutile titanium dioxide, and 1 part of epoxy resin, add water and disperse uniformly through a coating dispersion system to obtain a top-coating coating (solid content 62%, viscosity 500 cp), coat the top-coating coating on the surface of the pre-coating layer on one side of the fiber layer using a doctor blade coating process, coating amount 8 g / m 2 , infrared hot air drying at 120°C, speed 650 m / min, to form a top-coating layer;

[0077] (4) Use a multi-roll super-calender to finish the label paper obtained in step (3), speed 800 m / min, linear pressure 78 kN / m, nip temperature 120°C, to obtain an oil-proof label paper.

[0078] Comparative Example 1

[0079] This comparative example provides a method for preparing an oil-proof label paper, the specific steps refer to Example 1, the only difference is that step (2) is omitted, and only the top-coating coating is coated on one side of the fiber layer.

[0080] Comparative Example 2

[0081] This comparative example provides a method for preparing an oil-proof label paper, the specific steps refer to Example 2, the only difference is that step (3) is omitted, and only the pre-coating coating is coated on both sides of the fiber layer.

[0082] Comparative Example 3

[0083] This comparative example provides a method for preparing an oil-proof label paper, the specific steps refer to Example 2, the only difference is that the rutile titanium dioxide in step (3) is replaced with an equal amount of heavy calcium carbonate.

[0084] Comparative Example 4

[0085] The comparative example provides a preparation method of an oil-proof label paper, and the specific steps refer to example 2, and the only difference is that the pre-coat coating is replaced by carboxymethyl cellulose (solid content 7%), the pre-coat coating is coated by using a metering rod coating process, and the single-side coating amount is 15 g / m 2 .

[0086] Experimental example

[0087] The oil-proof label papers obtained by the examples and the comparative example are subjected to performance testing, and the testing methods of various indexes are as follows:

[0088] 1. Water permeability: the paper sample is cut into a size of 60x60 mm, and the sample is taken from an edge of more than 12 cm; an appropriate amount of water (23°C) is placed in a surface dish, two drops of blue ink are dropped, and stirring is uniformly performed; the front surface of the paper sample (i.e., the side coated with the coating) is placed upward into the water (the back surface contacts the water), and the stopwatch is started from the time when the paper sample is placed into the water, and the timing is stopped when the first water permeation point appears; the minimum seconds are recorded as the detection result of the water permeability.

[0089] 2. Oil-proof grade: the KIT method is used for testing, wherein the front surface refers to the side coated with the coating;

[0090] 3. Smoothness: the testing is performed according to GB / T456;

[0091] 4. Opacity: the testing is performed according to GB / T1543;

[0092] 5. Glossiness: the testing is performed according to GB / T8941.

[0093] The test results obtained by using the above method are as follows:

[0094] Table 1 Performance indexes of the oil-proof label paper

[0095]

[0096] As shown in Table 1, the oil-proof label paper prepared by the embodiment of the present application can achieve strong oil resistance on both the front and back sides, the front side can achieve more than 10 levels, and the back side can achieve more than 6 levels, and also has excellent water resistance, gloss, smoothness and opacity, and can be used as a label for packaging edible oil and other oil-containing foods. It is found from Comparative Example 1 that only a top coating layer is coated on one side of the fiber layer, the front side can achieve an oil resistance level of 8, but the back side can only achieve an oil resistance level of 3, which is prone to cause the problem of oil stains on the pasted surface, and in addition, the water resistance and smoothness are far inferior to those of Example 1. It is found from Comparative Example 2 that after the fiber layer on both sides is coated with a pre-coating layer, the front and back sides can achieve an oil resistance level of 8, but the water resistance and smoothness are poor, and the opacity is also weak, which affects the printing aesthetics. It is found from Comparative Example 3 that the top coating layer is composed of flaky kaolin and rutile titanium dioxide, which significantly improves the front oil resistance level, smoothness, opacity and gloss compared with replacing rutile titanium dioxide with calcium carbonate commonly used in the art, and has a significant advantage. It is found from Comparative Example 4 that the pre-coating layer provided by the present application can simultaneously impart higher oil resistance to the front and back sides of the label paper compared with the pre-coating layer of carboxymethyl cellulose, has a significant advantage, and also has certain improvement in water resistance, front side smoothness and gloss.

[0097] The oil-proof label paper prepared by Examples 1-3 of the present application can achieve good oil resistance on both the front and back sides, and also has good flatness and firmness during the labeling process, and no label slipping phenomenon is found after multiple high-speed printing and labeling experiments. However, when the top coating layer is used to replace the pre-coating layer on the back side of the fiber layer, although the back side of the label paper can be imparted good oil resistance, the label slipping phenomenon occurs during the labeling process due to the too smooth and water-resistant coating layer, which cannot meet the labeling requirements.

[0098] Obviously, the above examples are only examples for clarity and do not limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. An oil repellent label paper, characterized in that The application relates to an oil-proof label paper, which comprises a fiber layer, a pre-coating layer and a surface coating layer, the pre-coating layer is arranged on both sides of the fiber layer, and the surface coating layer is arranged on the pre-coating layer of one side of the fiber layer. The raw material of the fiber layer comprises the following components in parts by weight: 40 parts of bleached coniferous wood pulp, 50-55 parts of bleached broadleaf wood pulp, 5-10 parts of kaolin, 1.0 part of a wet strength agent, 0.12 part of alkyl alkene ketone dimer and 0.007 part of polyacrylamide, wherein the kaolin is superfine kaolin. The application further discloses a preparation method of the oil-proof label paper. The coating of the pre-coating layer comprises the following components by weight: 70-85 parts of modified starch, 15-30 parts of water-soluble polyacrylate copolymer, wherein the solid content of the pre-coating layer is 8-12%, and the viscosity is 10-55 cp; the single-side coating amount of the pre-coating layer is 3-8 g / m 2 ; The coating of the surface coating layer comprises the following components by weight: adhesive 15-25 parts, kaolin 70-75 parts, titanium white 3.5-10 parts, epoxy resin 1-1.5 parts, wherein the adhesive is selected from one of styrene acrylic latex, butadiene styrene latex and acrylic latex; the kaolin is selected from flaky kaolin; the titanium white is selected from rutile titanium white; the solid content of the surface coating layer is 55%-62%, the viscosity is 500-750 cp; the single-side coating amount of the surface coating layer is 8-13 g / m 2 .

2. The method of producing an oil-proof label paper according to claim 1, characterized by, (1) uniformly mixing the wood pulp, the kaolin and the functional additives in proportion, and preparing the fiber layer by using a papermaking process; (2) uniformly mixing modified starch and a water-soluble polyacrylate copolymer in proportion to obtain a pre-coating layer coating, coating the pre-coating layer coating on both sides of the fiber layer, and drying to form the pre-coating layer; (3) uniformly mixing the adhesive, the kaolin, titanium white and the epoxy resin in proportion to obtain a surface coating layer coating, coating the surface coating layer coating on the surface of the pre-coating layer of one side of the fiber layer, and drying to form the surface coating layer; (4) finishing the label paper obtained in the step (3) to obtain the oil-proof label paper.

3. The preparation method of the oil-proof label paper according to claim 2, wherein in the step (2), the pre-coating layer coating is coated by using a metering rod coating process, and drying is carried out by using an infrared hot air drying process, the temperature is 105-120 DEG C, and the speed is 350-700 m / min. In the step (3), the surface coating layer coating is coated by using a doctor blade coating process, and drying is carried out by using an infrared hot air drying process, the temperature is 105-120 DEG C, and the speed is 350-700 m / min. In step (1), when the fibrous layer is prepared using a papermaking process, the speed is 350 to 700 m / min and the basis weight is 45 to 70 g / m 2 ; In the step (4), the label paper is finished by using a super-calendering process, the speed is 800 m / min, the linear pressure is 70-85 kN / m, and the pressure zone temperature is 95-190 DEG C.

4. Application of the oil-proof label paper according to claim 1 or the oil-proof label paper prepared by the preparation method according to claim 2 or 3 in the packaging of products containing oil. ​ ​

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