JP2018053402A - Water- and oil-resistant paper and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-and oil-resistant paper that prevents the occurrence of blocking and shows high water and oil resistance.SOLUTION: The water- and oil-resistant paper contains a base paper provided with, at least on one side, a coating layer containing an inorganic pigment and a binder. The coating layer contains 50-100 pts.mass of the binder per 100 pts.mass of the inorganic pigment, 25 mass% or more of the total amount of the binder is an acrylic resin having a glass-transition temperature of 20-50°C, the coating layer contains 3-7 pts.mass of a film-forming assistant having a boiling point of 190-270°C per 100 pts.mass of the binder, and a coating amount of the coating layer is 10-18 g/mper one side of the base paper.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a water and oil resistant paper and a method for producing the same. More specifically, the present invention relates to a water / oil resistant paper having offset printing suitability and hardly causing blocking, and a method for producing the same.

  In fields such as packaging materials for freezing and wine labels, water- and oil-resistant paper such as laminated paper and synthetic paper that do not generate undulations or wrinkles even when wet due to condensation has been used. However, these water- and oil-resistant papers have a problem in incineration processing that generates a large amount of heat when incinerated, and some of them have poor offset printing suitability. Instead, a coating containing an aqueous binder and an inorganic pigment is used. Water- and oil-resistant paper with a layer is used.

As such a water and oil resistant paper, Patent Document 1 discloses a paint comprising 50 to 200 parts by weight of a mixture of acrylic dispersion (A) and styrene / butadiene dispersion (B) per 100 parts by weight of pigment. A water- and oil-resistant paper coated with 5 to 25 g / m ² is proposed.

JP 2002-13095 A

  However, the water- and oil-resistant paper of Patent Document 1 is satisfactory in water resistance and oil resistance (hereinafter sometimes referred to as “water and oil resistance”), but has a problem that blocking is likely to occur. Blocking is a phenomenon in which paper sticks to each other, and occurs when the coated layers of the coated paper stick to each other when stored in the form of winding or cut into a flat plate and stacked. There are many cases. When such blocking occurs, there is a possibility of causing a paper feed failure to a printing machine or the like.

  One method for suppressing blocking is to use a binder having a relatively high glass transition temperature. However, as the glass transition temperature of the binder increases, the film formability of the coating layer decreases, and as a result, the water and oil resistance tends to decrease. In particular, when the coating amount of the coating layer is relatively small, it has been difficult to satisfy the water and oil resistance.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a water- and oil-resistant paper that is hardly blocked and has high water and oil resistance.

  Other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the following description.

The water / oil resistant paper of the present invention is a water / oil resistant paper having a coating layer containing an inorganic pigment and a binder on at least one surface of a base paper, and the coating layer has 100 parts by weight of an inorganic pigment. 50-100 mass parts binder is contained, 25 mass% or more of the binder total amount is an acrylic resin having a glass transition temperature of 20-50 ° C., and the coating layer has a boiling point of 190-270 ° C. 3 to 7 parts by mass with respect to 100 parts by mass of the binder, and the coating amount of the coating layer is 10 to 18 g / m ² per one side of the base paper. .

  According to such a configuration, by making 25% by mass or more of the total amount of the binder an acrylic resin having a glass transition temperature of 25 to 50 ° C., the water resistance is excellent, and blocking is difficult to occur, and the boiling point is further reduced. By adding a film forming auxiliary at 190 to 270 ° C., the water and oil resistance can be further improved and a water and oil resistant paper having high water and oil resistance can be obtained.

  In a preferred embodiment of the present invention, the binder may further include a styrene-butadiene resin. According to such a configuration, it is possible to provide higher water and oil resistance by using the acrylic resin and the styrene-butadiene resin together.

In addition, the water- and oil-resistant paper according to the present invention has a JAPAN TAPPI No. 1 in which the surface of the coating layer is the measurement surface. It is preferable that the oil resistance by the kit method of 41 is 7 or more and the water absorption at a contact time of 120 seconds by the Cobb method of JIS P 8140 is 3.0 g / m ² or less.

  In a preferred embodiment of the present invention, the glass transition temperature of the styrene-butadiene resin may be 0 to 50 ° C.

  According to such a configuration, by selecting a styrene-butadiene resin having a glass transition temperature of 0 to 50 ° C., oil resistance is further improved and blocking is less likely to occur.

  In a preferred embodiment of the present invention, the acrylic resin and the styrene-butadiene resin in the binder may be included in the range of acrylic resin: styrene-butadiene resin = 25: 75 to 75:25. .

  According to such a structure, since the compounding ratio of acrylic resin and styrene-butadiene resin is in an appropriate range, water resistance and oil resistance can be further improved.

  In a preferred embodiment of the present invention, 20 to 80% by mass of the total amount of the inorganic pigment may be one or more kinds of flat pigments selected from kaolin, delaminated clay or engineered kaolin. According to such a structure, oil resistance can be improved more according to the effect of a flat pigment.

  In a preferred embodiment of the present invention, the inorganic pigment may include one or more flat pigments selected from kaolin, delamiclay, or engineered kaolin, and calcium carbonate.

  According to such a configuration, calcium carbonate is effective in improving the water resistance, and the flat pigment is effective in improving the oil resistance. By using these together, the water resistance and the oil resistance are well balanced. Can be improved.

  In a preferred embodiment of the present invention, the film forming aid may include one or more selected from ethylene glycol diethyl ether, benzyl alcohol, butyl cellosolve, ester alcohol, and texanol.

  According to such a structure, it can be set as the water-resistant oil-resistant paper excellent in blocking resistance and water-and-oil resistance.

The present invention can also be understood as a method for producing water- and oil-resistant paper. The method for producing water- and oil-resistant paper of the present invention comprises a step of preparing a base paper, an inorganic pigment, 50 to 100 parts by mass of binder with respect to 100 parts by mass of inorganic pigment, and 3 to 7 with respect to 100 parts by mass of binder. A step of preparing a coating liquid containing part by mass of a film forming aid, and applying the coating liquid in a range of 10 to 18 g / m ^{2 in} terms of solid content on at least one surface of the base paper. Wherein 25% by mass or more of the total amount of the binder is an acrylic resin having a glass transition temperature of 20 to 50 ° C., and the film forming aid has a boiling point of 190 to 270 ° C. Is. According to such a configuration, it is difficult to produce blocking, and a water- and oil-resistant paper having high water and oil resistance can be easily produced.

  According to the present invention, it is possible to obtain a water- and oil-resistant paper that hardly causes blocking and has high water and oil resistance.

It is a chart which shows the mixing | blending of the coating layer in an Example. It is a chart which shows the mixing | blending of the coating layer in a comparative example. It is a graph which shows the physical property of the water-resistant oil-resistant paper obtained by the Example and the comparative example.

  Hereinafter, the present invention will be described, but the present invention is not construed as being limited to these embodiments.

  As the base paper used in the present invention, a base paper containing pulp as a main component can be used. As pulp used for the base paper, chemical pulp such as LBKP (hardwood bleached kraft pulp), NBKP (softwood bleached kraft pulp), TMP (thermomechanical pulp), GP (crushed wood pulp), CTMP (chemothermomechanical pulp), RMP (refiner mechanical pulp), mechanical pulp such as DIP (deinked pulp), and non-wood pulp such as cotton, kenaf, bamboo, bagasse, etc. Can do. From the viewpoint of environmental conservation, it is preferable to contain ECF (Elemental Chlorine Free) pulp and TCF (Total Chlorine Free) pulp.

  Here, the base paper is a filler, an internal sizing agent, a paper strength enhancer, a pitch control agent, a fluorescent whitening agent, a coloring dye, a coloring pigment, and a fluorescent decoloring as long as the intended effect of the invention is not impaired. Various known paper additives such as an agent can be appropriately blended.

  In the present invention, the base paper can be made using a papermaking raw material containing pulp and a papermaking additive. The paper making method is not particularly limited, and various paper machines such as a twin wire paper machine, a long paper machine, a circular multi-layer paper machine, a long multi-layer paper machine, a circular net paper machine, and a long-mesh multi-layer paper machine. You can use the machine.

  In the present invention, a coating layer containing an inorganic pigment, a binder, and a film forming aid is provided on at least one surface of the base paper.

  Inorganic pigments to be included in the coating layer include light calcium carbonate and heavy calcium carbonate calcium carbonate, calcium sulfate, kaolin, delaminated clay, engineered kaolin, calcined kaolin, clay, talc, magnesium carbonate, magnesium oxide, silicic acid, silicic acid Inorganic pigments such as salt, colloidal silica, satin white, aluminum hydroxide, calcium hydroxide, zinc hydroxide, zinc oxide, barium sulfate, titanium oxide, white clay, synthetic amorphous silica, bentonite and the like can be used. By including an inorganic pigment in the coating layer, it is possible to impart printing suitability to offset printing or the like on the water and oil resistant paper.

  In the present invention, among these inorganic pigments, it is preferable to use calcium carbonate in combination with one or more flat pigments selected from kaolin, delamy clay or engineered kaolin, particularly 20 to 80% by mass of the inorganic pigment, Preferably, oil resistance is easily improved by using 30 to 70% by mass as a flat pigment.

  In the coating layer of the present invention, the binder is contained in the range of 50 to 100 parts by mass with respect to 100 parts by mass of the inorganic pigment, and more preferably in the range of 60 to 80 parts by mass. If the blending amount of the binder is less than 50 parts by mass, the water and oil resistance cannot be satisfied. Conversely, if it exceeds 100 parts by mass, blocking tends to occur.

  As a binder to be included in the coating layer, acrylic resin, styrene-butadiene resin, acrylonitrile-butadiene resin, ethylene vinyl acetate resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, silicon resin, However, 25% by mass or more, preferably 40% by mass or more of the total binder is used as an acrylic resin having a glass transition temperature of 20 to 50 ° C. The acrylic resin is essential for imparting water resistance to the coating layer. If the ratio of the acrylic resin to the total amount of the binder is less than 25% by mass, sufficient water resistance cannot be imparted to the coating layer.

  Furthermore, blocking can be suppressed by using an acrylic resin having a glass transition temperature of 20 to 50 ° C. among the acrylic resins. If the glass transition temperature of the acrylic resin is less than 20 ° C., blocking is likely to occur, and conversely if the glass transition temperature exceeds 50 ° C., the film forming property is lowered, or the water and oil resistance is lowered. In addition, as an acrylic resin used here, it can select from a well-known thing suitably, and can use it, However, Among these, the styrene-acryl copolymer resin excellent in the improvement effect of water resistance is preferable.

  In the present invention, an acrylic resin is used as a binder as described above. However, since oil resistance is further improved by using an acrylic resin and a styrene-butadiene resin in combination, a styrene-butadiene resin is also used. It is preferable. Here, the blending ratio of the acrylic resin and the styrene-butadiene resin is not particularly limited, but is preferably acrylic resin: styrene-butadiene resin = 25: 75 to 75:25. If the ratio of the styrene-butadiene resin exceeds 75, there is a possibility that the problem of blocking between the coating layer surfaces tends to occur. On the other hand, if the ratio of the styrene-butadiene resin is less than 25, the oil resistance cannot be satisfied. There is a fear.

  As the styrene-butadiene resin used in the present invention, a styrene-butadiene copolymer is suitable. Moreover, 0-50 degreeC is preferable and, as for the glass transition temperature of a styrene-butadiene type resin, More preferably, it is 10-40 degreeC.

  As described above, in the present invention, a coating aid is included in the coating layer. The coating layer of the present invention uses a binder having a relatively high glass transition temperature. By selecting such a binder, blocking can be suppressed, while water and oil resistance is hardly improved at a low coating amount. However, by including a film forming aid here, it is possible to improve water and oil resistance while suppressing blocking.

  In the present invention, as the film forming aid, among the film forming aids used in paints such as paints and adhesives (see Patent Nos. 384269 and 5307443), those having a boiling point of 190 to 270 ° C. Use. As such a film forming aid, ethylene glycol diethyl ether, benzyl alcohol, butyl cellosolve, ester alcohol, and texanol can be used, but texanol is particularly preferable from the balance of film forming property and blocking. If the boiling point of the film forming aid is lower than 190 ° C., the water and oil resistance cannot be improved, and if it exceeds 270 ° C., the coating layer becomes too soft, or blocking tends to occur.

  Content of the film-forming auxiliary agent in a coating layer shall be 3-7 mass parts with respect to 100 mass parts of binders. When the content of the film forming aid is in the above range, the coating layer can satisfy high water / oil resistance while suppressing blocking. When the content of the film-forming auxiliary is less than 3 parts by mass, the water and oil resistance cannot be satisfied. Conversely, when the content exceeds 7 parts by mass, the water and oil resistance is satisfactory, but blocking tends to occur.

In the present invention, a coating solution for a coating layer is applied to at least one surface of the base paper and dried to provide a coating layer. The coating amount of the coating layer per side of the base paper, 10~18g / m ² in terms of solid content, preferably 12~16g / m ^2. If the coating amount is less than 10 g / m ² , the coating layer cannot sufficiently cover the base paper, and the water and oil resistance cannot be satisfied. Conversely, if the coating amount exceeds 18 g / m ² , the water and oil resistance can be satisfied, but blocking tends to occur.

  Moreover, the application method to the base paper of a coating liquid is not specifically limited, The well-known coating apparatus used in the general coated paper manufacturing field can be used suitably. For example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a curtain coater, a bar coater, a gravure coater, a size press coater, a bill blade coater, and the like can be used.

As a measure of the water resistance of the water- and oil-resistant paper of the present invention, it is recognized that the water absorption is 3 g / m ² or less with Cobb water absorption at a contact time of 120 seconds according to JIS P 8140. In addition, as a measure of oil resistance, JAPAN TAPPI paper pulp test method No. 41 (2000), paper and paperboard-oil repellency test method-kit method If the oil resistance in the oil resistance is 7 or more, it is recognized as having sufficient oil resistance.

  Examples of the water and oil resistant paper according to the present invention will be specifically described below, but the present invention is not limited thereto. In addition, unless otherwise indicated, the part and% in each Example and a comparative example show a dry mass part and mass%.

Example 1
<Creation of base paper>
Add 1.0 parts by weight of sulfuric acid band and 3.0 parts by weight of light calcium carbonate as a filler to a pulp dispersion consisting of 60 parts by weight of hardwood bleached kraft pulp (350 ml CSF) and 40 parts by weight of softwood bleached kraft pulp (450 ml CSF). Then, 0.2 parts by mass of rosin sizing agent and 0.7 parts by mass of cationic starch were added to make paper. As the surface treatment agent, oxidized starch was applied to the base paper by a total of 3.2 g / m ^{2 on} both sides of the base paper, and the surface sizing agent was applied to the base paper on both sides by a total of 1.6 g / m ² . A base paper having a basis weight of 100 g / m ² was made.

<Preparation of coating solution for coating layer>
As inorganic pigments, kaolin (trade name: Century HC, manufactured by IRCC, Brazil) 60 parts by mass, heavy calcium carbonate (trade name: Softon # 2200, manufactured by Bihoku Powdered Company), and titanium oxide (trade name) : CR-85, manufactured by Ishihara Sangyo Co., Ltd.) 20 parts by mass, and further added 0.4 parts of a dispersant (trade name: Aron T-50, 40% concentration, manufactured by Toa Gosei Co., Ltd.) An inorganic pigment dispersion having a solid content of 60% was prepared using a disperser. Next, in the inorganic pigment dispersion, 30 parts by mass of a styrene acrylic copolymer (trade name: Cybinol EK-81, glass transition temperature: 40 ° C., made by Seiden Chemical Co., Ltd.) as a binder, and a styrene butadiene copolymer (product) Name: PA-3820, glass transition temperature: 21 ° C., manufactured by Nippon A & L Co., Ltd., 40 parts by mass, and a film forming aid (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) 4 .9 parts by mass (based on 7% by mass of the binder) was added and stirred to prepare a coating solution for a coating layer having a solid content concentration of 50%.

<Coating of coating layer>
Apply the coating solution for the coating layer on both sides of the base paper with an air knife coater so that the solid coating amount per side of the base paper is 14.0 g / m ² and dry. A water and oil resistant paper having a final moisture content of 6% by mass was produced.

(Example 2)
In Example 1, except that the addition amount of the film-forming auxiliary (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) was changed to 2.1 parts by mass (3% by mass of binder). In the same manner as in Example 1, a water and oil resistant paper was obtained.

(Example 3)
In Example 1, the amount of film forming aid (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) was changed to 2.1 parts by mass (3% by mass of binder), and coating was performed. A water- and oil-resistant paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid for the layer was 16 g / m ^{2 in} terms of solid text per side of the base paper.

Example 4
In Example 1, as a binder, a styrene acrylic copolymer (trade name: Cybinol EK-81, glass transition temperature: 40 ° C., manufactured by Seiden Chemical Co., Ltd.) and a styrene butadiene copolymer (trade name: PA-3820, Glass transition temperature: 21 ° C., manufactured by Nippon A & L Co., Ltd. was not added. Instead, 80 parts by mass of a styrene copolymer (trade name: Cybinol EK-61, glass transition temperature: 24 ° C., manufactured by Seiden Chemical Co., Ltd.) was added. Except for the above, water and oil resistant paper was obtained in the same manner as in Example 1.

(Example 5)
In Example 1, the inorganic pigment to be added to the coating layer coating solution is kaolin (trade name: Century HC, manufactured by IRCC, Brazil), 80 parts by mass, heavy calcium carbonate (trade name: Softon # 2200, A water- and oil-resistant paper was obtained in the same manner as in Example 1 except that 20 parts by mass of Bihoku Flour Chemical Co., Ltd.) and titanium oxide (trade name: CR-85, manufactured by Ishihara Sangyo Co., Ltd.) were not added. In the adjustment of the water / oil resistant coating, the inorganic pigment is kaolin (trade name: Century HC, average particle size 0.9 μm, manufactured by IRCC, Brazil), heavy calcium carbonate (trade name: Softon # 2200, average particle size). A water- and oil-resistant paper was obtained in the same manner as in Example 1 except that the content was changed to 20 parts by mass (1.1 μm, manufactured by Bihoku Powder Chemical Co., Ltd.).

(Example 6)
In Example 1, the amount of the inorganic pigment added to the coating layer coating solution was 20 parts by weight of kaolin (trade name: Century HC, manufactured by IRCC, Brazil), heavy calcium carbonate (trade name: Softon #). 2200, manufactured by Bihoku Powder Chemical Co., Ltd.) 60 parts by mass and titanium oxide (trade name: CR-85, manufactured by Ishihara Sangyo Co., Ltd.) 20 parts by mass were obtained in the same manner as in Example 1 to obtain a water and oil resistant paper.

(Example 7)
In Example 1, 4.9 parts by mass (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) of 4.9 parts by mass (based on binder 7% by mass) A water- and oil-resistant paper was obtained in the same manner as in Example 1 except that it was changed to 4.9 parts by mass (with respect to binder 7% by mass) (Dawanol DPM, boiling point: 190 ° C., dipropylene glycol methyl ether, manufactured by Dow Chemical Company).

(Example 8)
In Example 1, 4.9 parts by mass (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) of 4.9 parts by mass (based on binder 7% by mass) Water and oil-resistant paper was obtained in the same manner as in Example 1 except that it was changed to 4.9 parts by mass (with respect to binder 7% by mass) (Dawanol DPnB, boiling point 229 ° C., dipropylene glycol-n-butyl ether, manufactured by Dow Chemical Co., Ltd.). .

(Comparative Example 1)
In Example 1, except for changing the addition amount of the film-forming aid (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) to 6.3 parts by mass (vs. binder 9% by mass). In the same manner as in Example 1, a water and oil resistant paper was obtained.

(Comparative Example 2)
In Example 1, this was carried out except that the amount of film forming aid (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) was changed to 0.7 parts by mass (1% by mass of binder). In the same manner as in Example 1, a water and oil resistant paper was obtained.

(Comparative Example 3)
In Example 1, 30 parts of a styrene-acrylic copolymer (trade name: Cybinol EK-81, glass transition temperature: 40 ° C., manufactured by Seiden Chemical Co., Ltd.) to be added as a binder was added to a styrene-acrylic copolymer (mobile LDM6740, glass). (Transition temperature: 15 ° C., manufactured by Nippon Synthetic Chemical Co., Ltd.) A water- and oil-resistant paper was obtained in the same manner as in Example 1 except for changing to 30 parts.

(Comparative Example 4)
In Example 1, 30 parts of a styrene acrylic copolymer (trade name: Cybinol EK-81, glass transition temperature: 40 ° C., manufactured by Seiden Chemical Co., Ltd.) to be added as a binder was added to a styrene acrylic copolymer (trade name: JONCRYL586). Water transition oil resistant paper was obtained in the same manner as in Example 1 except that the glass transition temperature was changed to 30 parts.

(Comparative Example 5)
In Example 1, a water- and oil-resistant paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid for the coating layer was set to 9.0 g / m ² on one side of the base paper. .

(Comparative Example 6)
In Example 1, a water- and oil-resistant paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid for the coating layer was 20.0 g / m ² per one side of the base paper. .

(Comparative Example 7)
In Example 1, 4.9 parts by mass (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) of 4.9 parts by mass (based on binder 7% by mass) Progreide DMM, boiling point: 175 ° C., dipropylene glycol dimethyl ether, manufactured by Dow Chemical Co., Ltd.) Except for changing to 2.1 parts (with respect to 3% by mass of binder), water and oil resistant paper was obtained in the same manner as in Example 1.

(Comparative Example 8)
In Example 1, 4.9 parts by mass (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) of 4.9 parts by mass (based on binder 7% by mass) Water and oil-resistant paper was obtained in the same manner as in Example 1 except that it was changed to 4.9 parts by mass (with respect to binder 7% by mass) (Dawanol TPnB, boiling point 274 ° C., tripropylene glycol-n-butyl ether, manufactured by Dow Chemical Co.). .

(Comparative Example 9)
In Example 1, a water- and oil-resistant paper was obtained in the same manner as in Example 1 except that the film forming aid (trade name: CS-12, boiling point: 253 ° C., Texanol, manufactured by JNC) was not added.

[Cobb water absorption]
In accordance with JIS P 8140: 1998 paper and paperboard-water absorption test method (Cobb method), the water absorption at a contact time of 120 seconds was measured.

[Kit method oil resistance]
JAPAN TAPPI No. 41: 2000 Paper and paperboard were measured by the oiliness test method (kit method).

[Blocking resistance]
4 layers of water- and oil-proof paper cut to 10 cm long × 5 cm wide are stacked and sandwiched between aluminum plates, and then left under pressure at 23 ° C. for 24 hours under a load of 50 kgf / cm. The adhesion situation was evaluated. The evaluation of the adhesion state was evaluated as the following three-step evaluation, where ◯ and Δ were acceptable levels.
○: Not adhered at all △: Slightly adhered but easily peeled ×: Entire surface adhered and not easily peeled off

  The structure of the coating layer of the water and oil resistant paper obtained in each example and each comparative example is shown in FIGS. 1 and 2, and the evaluation result of each water and oil resistant paper is shown in FIG.

  As is clear from FIG. 3, the water and oil resistant paper obtained in Examples 1 to 8 was excellent in water and oil resistance and excellent in blocking resistance.

  On the other hand, the water- and oil-resistant paper obtained in Comparative Example 1 was inferior in blocking resistance because the amount of film forming aid added was too large. In addition, since the water-resistant and oil-resistant paper obtained in Comparative Example 9 was not added with the film-forming auxiliary, the water-resistant oil-resistant paper obtained in Comparative Example 2 was too water-resistant because the amount of the film-forming auxiliary added was too small. It was inferior in oil resistance.

  Further, the water and oil resistant paper obtained in Comparative Example 3 was inferior in blocking resistance because the glass transition temperature of the acrylic resin was too low. On the contrary, the water and oil resistant paper obtained in Comparative Example 4 was inferior in water and oil resistance because the glass transition temperature of the acrylic resin was too high.

  In addition, the water and oil resistant paper obtained in Comparative Example 5 is inferior in water and oil resistance because the coating amount of the coating layer is too small. Conversely, the water and oil resistant paper obtained in Comparative Example 6 is Since there was too much coating amount of a construction layer, it became inferior to blocking resistance.

  Further, the water and oil resistant paper obtained in Comparative Example 7 was inferior in water and oil resistance because the film forming aid had a boiling point of less than 190 ° C. On the contrary, the water and oil resistant paper obtained in Comparative Example 8 was inferior in blocking resistance because the boiling point of the film forming aid exceeded 270 ° C.

Claims (9)

A water- and oil-resistant paper having a coating layer containing an inorganic pigment and a binder on at least one surface of a base paper,
The coating layer contains 50 to 100 parts by mass of binder with respect to 100 parts by mass of the inorganic pigment,
25% by mass or more of the total amount of the binder is an acrylic resin having a glass transition temperature of 20 to 50 ° C.,
The coating layer contains 3 to 7 parts by mass of a film forming auxiliary having a boiling point of 190 to 270 ° C. with respect to 100 parts by mass of the binder,
The water- and oil-resistant paper, wherein the coating amount of the coating layer is 10 to 18 g / m ² per side of the base paper.   The water- and oil-resistant paper according to claim 1, further comprising a styrene-butadiene resin as the binder. When the surface of the coating layer was the measurement surface, JAPAN TAPPI No. The oil resistance according to the kit method of 41 is 7 or more, and the water absorption at a contact time of 120 seconds according to the Cobb method of JIS P 8140 is 3.0 g / m ² or less. Water and oil resistant paper.   The water / oil resistant paper according to claim 2 or 3, wherein the styrene-butadiene resin has a glass transition temperature of 0 to 50 ° C.   The acrylic resin and the styrene-butadiene resin in the binder are included in the range of acrylic resin: styrene-butadiene resin = 25: 75 to 75:25. Water- and oil-resistant paper as described in 1.   The water- and oil-resistant paper according to any one of claims 1 to 5, wherein 20 to 80% by mass of the total amount of the inorganic pigment is one or more kinds of flat pigments selected from kaolin, delaminated clay and engineered kaolin. .   The water- and oil-resistant paper according to any one of claims 1 to 6, wherein the inorganic pigment includes one or more types of flat pigments selected from kaolin, delamiclay, or engineered kaolin and calcium carbonate.   The water- and oil-resistant paper according to any one of claims 1 to 7, wherein the film forming aid includes one or more selected from ethylene glycol diethyl ether, benzyl alcohol, butyl cellosolve, ester alcohol, and texanol. . Preparing a base paper;
Preparing a coating liquid comprising an inorganic pigment, a binder of 50 to 100 parts by mass with respect to 100 parts by mass of the inorganic pigment, and a film forming aid of 3 to 7 parts by mass with respect to 100 parts by mass of the binder;
Coating the coating liquid on at least one surface of the base paper in a range of 10 to 18 g / m ^{2 in} terms of solid content,
25% by mass or more of the total amount of the binder is an acrylic resin having a glass transition temperature of 20 to 50 ° C., and the boiling point of the film forming aid is 190 to 270 ° C. Production method.

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