JP5215638B2 - Water and oil resistant paper and method for producing the same - Google Patents

Description

  The present invention relates to a water- and oil-resistant paper used for paper plates and food packaging, and a method for producing the same.

  Oil-resistant paper is a generic term for “1) oil-resistant paper in JIS P 0001: 1998“ Paper / Board and Pulp Terminology. ”Reference: Paper made with highly beaten chemical pulp and oils and fats There are papers that have been chemically treated and / or coated to be resistant to 2) papers or paperboards that are extremely resistant to the penetration of grease or fat, eg some types of paper, eg carbon The base paper completely prevents the penetration of these substances. "

  Examples of the oil resistant paper include glassine paper, polyethylene processed paper, vinylidene chloride processed paper, moisture-proof cellophane paper, and aluminum foil laminated paper.

  Some oil-resistant papers require air permeability in addition to oil resistance. For example, packaging paper such as a hamburger requires both oil resistance that does not allow oils and fats to pass and air permeability that allows water vapor to pass. . However, the glassine paper is good because it has a mechanism for reducing the gaps in the base paper by finishing the base paper at a high density or a mechanism for closing the gaps in the base paper by applying, impregnating or pasting an oil-resistant material. Oil resistance is obtained, but air permeability is not obtained.

  In order to obtain air permeability while imparting oil resistance, there is a method of making the critical surface tension of the processed surface smaller than the surface tension of the oily substance. The method of using a fluorine-based oil-resistant agent containing a fluorine-based compound such as a perfluorinated hydrocarbon acrylate or a phosphoric acid ester of perfluorinated hydrocarbon is referred to as an oil-resistant agent. The method has become mainstream. In the method using a fluorinated oil proofing agent, it is a mechanism that lowers the surface tension of the paper and reduces the wettability of the oil to prevent the penetration of the oil, and it is not necessary to reduce or close the gap of the base paper. Permeability equivalent to that of a new base paper is maintained. Furthermore, when using a fluorinated oil-resistant agent, when oil-resistant paper is used, the oil is sufficiently repelled on the surface, so that the voids through which the gas passes are not easily blocked by the oil, and as a result, the gas permeability is unlikely to decrease. . For these reasons, oil-resistant agents treated with fluorine-based oil-resistant agents are widely used (see, for example, Patent Document 1 or Patent Document 2). At the same time, the fluorine-based oilproofing agent is characterized by being able to impart water resistance.

JP 2000-169735 A JP 2001-98033 A

  However, in recent years, a problem has been raised that a fluorine-based oil proofing agent manufacturer generates off-gas of a perfluoroalkyl compound having a carbon chain length of 8 or more when heated in a microwave oven or the like. In addition, there are problems such as global environmental impact of perfluorooctanoic acid that is used as a raw material for fluorinated oilproofing agents and may remain in the final product. Perfluoroalkyl having a carbon chain length of 8 or more The use of fluorine-based oil-resistant agents containing compounds in water-resistant and oil-resistant paper for foods has been stopped. Furthermore, in order to solve these problems, a perfluoroalkyl group fluorine-based oil resistance agent having a carbon chain length of 6 or less has been proposed. However, for properties such as oil resistance and water resistance, the carbon chain length is 8 The current situation is inferior to the above-described perfluoroalkyl group fluorine-based oil resistance agents.

  Therefore, the present invention was created to solve such problems. The purpose is to use a perfluoroalkyl group fluorine-based oil resistant agent having a carbon chain length of 6 or less, which is not a concern for environmental problems, to bring the oil resistance, water resistance and air permeability to practical levels as water-resistant oil-resistant paper for foods. That is.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have permeated a perfluoroalkyl group fluorine-based oil resistant agent having a carbon chain length of 6 or less into a base paper mainly composed of porous fibers, and adhered. And the present invention has been completed by finding that it can be solved by performing a temperature aging treatment. That is, the oil-resistant paper according to the present invention is a water-resistant oil-resistant paper in which a fluorocarbon oil-containing agent containing a perfluoroalkyl compound is infiltrated and adhered to a base paper mainly composed of porous fibers. Is a compound having only a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group, and the adhesion amount of the fluorinated oilproof agent is 0.3 g / m ² or more as a solid content, and Further, after drying the base paper to which the fluorine-based oilproof agent is infiltrated and attached, a temperature aging treatment is further performed at 40 ° C. or more for 3 days or more .

In the oil-resistant paper according to the present invention, the amount of the fluorine-based oil-resistant agent attached is preferably ² g / m ² or less as a solid content. The gap between the porous fibers is not blocked by the fluorine-based oilproofing agent, and the air permeability is not deteriorated, and more than necessary fluorine-based oilproofing agent is not used.

In the water- and oil-resistant paper according to the present invention, the oil resistance specified in TAPPI UM 557 “Repelency of Paper and Board to Grade, Oil, and Waxes (Kit Test)” is 5th grade or more, and JIS P 8117: 1998 “ Paper and paperboard—Air permeability test method—Gurley test machine method ”and the air resistance specified in“ Gurley test machine method ”is 50 seconds or less, and JAPAN TAPPI paper pulp test method no. 68: 2000 It is preferable that the water repellency specified in "Paper and paperboard-water repellency test method" is R4 or more. By performing temperature aging, the three conditions of oil resistance, air resistance, and water repellency can be satisfied. Further, the water and oil resistant paper according to the present invention is a water and oil resistant paper in which a fluorocarbon oil-containing agent containing a perfluoroalkyl compound is infiltrated and adhered to a base paper mainly composed of porous fibers. The compound is a compound having only a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group, and the adhesion amount of the fluorinated oilproof agent is 0.3 g / m ² or more as a solid content , In addition, a temperature aging treatment is performed until the condition 1 is further satisfied after the base paper to which the fluorine-based oil proofing agent has been impregnated and dried is dried.
(Condition 1) The oil resistance specified in TAPPI UM 557 “Repelency of Paper and Board to Grade, Oil, and Waxes (Kit Test)” is 5th grade or higher, and JIS P 8117: 1998 “Paper and board-transparent” The air permeability resistance defined by “Temperature Test Method—Gurley Tester Method” is 50 seconds or less, and JAPAN TAPPI Paper Pulp Test Method No. 68: 2000 “Paper and paperboard—water repellency test method” has a water repellency specified by R4 or more.

Further, the method for producing a water and oil resistant paper according to the present invention comprises a step of making a base paper mainly composed of porous fibers, and a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group on the base paper. A step of infiltrating a fluorine-containing oil-proofing agent containing a compound having only from one side of the base paper, drying the base paper, and 0.3 g / m of the fluorine-based oilproofing agent as a solid content on the base paper It has the process of attaching ² or more, and the process of performing the temperature aging process for 3 days or more at 40 degreeC or more, It is characterized by the above-mentioned.

  In the method for producing water- and oil-resistant paper according to the present invention, it is preferable that the fluorine-based oil-resistant agent is permeated into the base paper by a coating machine attached to the paper machine. The production efficiency of water and oil resistant paper can be increased.

  The water and oil resistant paper of the present invention is a water and oil resistant paper having oil resistance and water resistance at a practical level as a water and oil resistant paper for foods while having air permeability equivalent to general paper.

  Hereinafter, although an embodiment is shown and explained in detail about the present invention, the present invention is limited to these descriptions and is not interpreted. Further, the embodiment may be modified as long as the effects of the present invention are achieved.

The water and oil resistant paper according to the present embodiment is a water and oil resistant paper in which a fluorocarbon oil-containing agent containing a perfluoroalkyl compound is infiltrated and adhered to a base paper mainly composed of porous fibers. , A compound having a perfluoroalkyl group having a carbon chain length of 6 or less, and the adhesion amount of the fluorinated oil proofing agent is 0.3 g / m ² or more as a solid content, and the fluorinated oil proofing agent is infiltrated. After the base paper adhered in this manner is dried, a temperature aging treatment is further performed.

Here, the water and oil resistant paper according to the present embodiment includes, for example, a step of making a base paper mainly composed of porous fibers, and a compound having a perfluoroalkyl group having a carbon chain length of 6 or less on the base paper. A step of infiltrating the fluorine-based oilproof agent from at least one side of the base paper, a step of drying the base paper, and attaching a fluorine-based oilproof agent to the base paper in an amount of 0.3 g / m ² or more as a solid content, and 40 ° C. or higher. And a step of performing a temperature aging treatment for 3 days or more.

  The porous fibers are mainly composed of wood pulp fibers because of their availability, but other non-wood pulp fibers may be used. Wood pulp is recycled from chemical pulp such as softwood kraft pulp, hardwood kraft pulp, sulfite pulp, stone grind pulp, thermomechanical pulp, mechanical pulp of refiner grind pulp, or newspaper, coated paper, fine paper, etc. Pulp can be used. Moreover, these can also be mix | blended suitably and used.

  The porous fiber is preferably beaten with a beater so that the Canadian Freeness Standard (CFS) is 550 to 250 ml, and more preferably 450 to 300 ml. For the purpose of adjusting the air permeability of the base paper, the degree of beating process (CFS) is appropriately adjusted. Here, if the beating process is advanced, the porosity of the porous fiber also increases.

  The base paper is mainly composed of porous fibers, but may be mixed with inorganic fibers and fillers. In addition, known internal additives such as dyes, paper strength agents, and wet strength agents can be added as necessary.

  The base paper is made by a long paper machine, a circular paper machine, a long paper machine with a top wire, a short paper machine, or a combination paper machine thereof, but is not limited thereto. .

  As the fluorine-based oilproofing agent, a fluorine-based oilproofing agent containing a compound having a perfluoroalkyl group having a carbon chain length of 6 or less is used. When a compound having a perfluoroalkyl group having a carbon chain length of 7 or more is used, problems such as concern for the environmental load occur. Of the compounds having a perfluoroalkyl group having a carbon chain length of 6 or less, those having a larger carbon chain length are preferred, and compounds having a perfluoroalkyl group having a carbon chain length of 5 or 6 are more preferred. This is because a larger carbon chain length provides better oil resistance, and a carbon chain length of 6 is most preferred.

  Additives can be added to the fluorine-based oilproofing agent solution as necessary. Examples of such additives include dispersants, antifoaming agents, thickeners, water resistance agents, plasticizers, fluorescent whitening agents, coloring pigments, coloring dyes, reducing agents, ultraviolet absorbers, antioxidants, There are fragrances or deodorants.

  The penetration of the fluorinated oil proofing agent into the base paper may be performed by an on-machine coating performed by a coating machine attached to the paper machine or by an off-machine coating performed by a coating machine separated from the paper machine. In the method for producing oil-resistant paper according to the present embodiment, in the step of infiltrating the fluorine-based oil resistant agent, it is preferable that the fluorine-based oil resistant agent is infiltrated into the base paper by a coating machine attached to the paper machine. As a result, the production efficiency of oil-resistant paper is increased. As the coating machine attached to the paper machine, a coating machine generally attached to the paper machine such as a size press, a gate roll, and a shim sizer can be used.

For drying the base paper infiltrated with the fluorinated oil proofing agent, a dryer generally attached to the paper machine such as a multi-cylinder paper machine or a Yankee paper machine can be used. By drying, the fluorine-based oilproof agent adheres to the base paper. The adhesion amount of the fluorinated oil proofing agent is 0.3 g / m ² or more as a solid content. More preferably, it is 0.5 g / m ² or more. If the adhesion amount of the fluorinated oil-proofing agent is less than 0.3 g / m ² as a solid content, the adhesion amount is insufficient, so that the oil resistance and water repellency cannot be practically used as food and oil-resistant paper. Further, adhesion of the fluorine-based oil-proofing agent is preferably 2 g / m ² or less as solids. If the amount of the fluorinated oil proofing agent exceeds ² g / m ² as a solid content, the fluorinated oil proofing agent may block the gap between the porous fibers and lower the air permeability. Will be used. In the present invention, as described above, an additive may be included in the solution of the fluorinated oil proofing agent. The amount of the fluorinated oil proofing agent refers to a perfluoroalkyl group having a carbon chain length of 6 or less. It may be determined that the amount is the same as the adhesion amount of the compound having.

  The drying temperature in the drying process of the base paper is, for example, 90 to 130 ° C.

  In addition, the water- and oil-resistant paper according to the present embodiment may have a preferable smoothness or dehydrated state by adjusting a press pressure, a drying temperature, a calendar pressure, a paper making speed, and the like, which are performed in a normal paper machine. it can.

  The water / oil resistant paper according to the present embodiment is subjected to a temperature aging (thermal aging) process as a final process after the drying process. Here, it is preferable to perform the temperature aging (thermal aging) treatment of the water / oil resistant paper at 40 ° C. or more, more preferably at 50 to 80 ° C. for 3 days or more, more preferably 5 to 10 days. When the temperature is lower than 40 ° C., the aging time may be long, or the treatment such as the improvement of water repellency may not be completed sufficiently. If the aging time is less than 3 days, the treatment such as water repellency may not be completed sufficiently, and if it exceeds 10 days, the treatment may be completed and time may be wasted. . The temperature aging treatment is preferably performed while being stored in an aging room. When the temperature aging treatment is performed, it is performed as it is with the water- and oil-resistant paper wound product, but may be performed after the water- and oil-resistant paper is cut into a predetermined size.

Before and after performing the temperature aging treatment, the morphological change observed on the appearance is not observed, but there is a change that the water repellency becomes particularly good. When the temperature aging treatment at 40 ° C. or higher for 3 days or more is completed, the water-resistant and oil-resistant paper according to the present embodiment is (Condition 1) TAPPI UM 557 “Repellency of Paper and Board to Green, Oil, and Wax (Kit Test)” The oil resistance specified in JIS P 8117: 1998 “Paper and paperboard—Air permeability test method—Gurley test machine method” has an air resistance of 50 seconds or less. It has temper and is a JAPAN TAPPI paper pulp test method No. 68: 2000 “Paper and paperboard—water repellency test method”, the water repellency specified by R 4 or higher. By checking whether the oil resistance, air permeability and water resistance satisfy the above condition 1 , it is possible to determine whether or not the temperature aging treatment has been properly completed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the content of this invention is not limited to an Example. “%” And “parts” indicate “mass%” and “parts by mass” in terms of solid content.

Example 1
[Preparation of paint]
A coating material was prepared by diluting with water using a fluorine-based oilproofing agent (trade name: AG-E060, manufactured by Asahi Glass Co., Ltd.). This fluorine-based oilproofing agent contains a compound having a perfluoroalkyl group having a carbon chain length of 6 as a main component.
[Making paper]
Coniferous pulp (N-BKP) and hardwood pulp (L-BKP) are mixed at a ratio of 30% and 70%, respectively, and beaten with a beating machine to a Canadian Freeness Standard (CFS) of 400 ml. did. To these pulp slurries, with respect to 100 parts of the total pulp, 0.3 parts of polyamidoepichlorohydrin (trade name: WS-4020, manufactured by Seiko PMC) as a wet strength agent and 0.14 parts of a sulfuric acid band were added. Paper making was performed with a net paper machine to obtain a base paper having a basis weight of 50 g / m ² .
[Penetration of paint]
Then, the base paper is directly impregnated with a size press installed in the long paper machine to impregnate the paint shown in [Preparation of paint] to a solid content of 1 g / m ² , dried with a dryer, A system oil proofing agent was adhered.
[aging]
Further, an aging treatment was performed at 50 ° C. for 5 days to obtain a water- and oil-resistant paper of Example 1.

(Example 2)
In Example 1, the water and oil resistant paper of Example 2 was obtained in the same manner as in Example 1 except that the period of aging treatment was changed to 7 days.

(Example 3)
In Example 1, a water- and oil-resistant paper of Example 3 was obtained in the same manner as in Example 1 except that the coating material was infiltrated and adhered to a solid content of 2 g / m ² .

Example 4
In Example 1, the water and oil resistant paper of Example 4 was obtained in the same manner as in Example 1 except that the temperature of the aging treatment was changed to 60 ° C.

(Example 5)
In Example 1, a water- and oil-resistant paper of Example 5 was obtained in the same manner as in Example 1, except that the paint was infiltrated and adhered so that the solid content was 0.5 g / m ² .

(Example 6)
In Example 1, a water-resistant and oil-resistant paper of Example 6 was obtained in the same manner as in Example 1 except that the coating material was infiltrated and adhered to a solid content of 0.3 g / m ² .

(Comparative Example 1)
In Example 1, a water- and oil-resistant paper of Comparative Example 1 was obtained in the same manner as in Example 1 except that no aging treatment was performed.

(Comparative Example 2)
In [Preparation of paint], dilute the fluorinated oil-resistant agent with water using an oil-resistant fluorinated oil-resistant agent (trade name: AG-530, manufactured by Asahi Glass Co., Ltd.) containing a perfluoroalkyl group having a carbon chain length of 8 or more. Thus, a water- and oil-resistant paper of Comparative Example 2 was obtained in the same manner as in Example 1 except that the coating material was prepared and the aging treatment was not performed.

(Comparative Example 3)
In [Preparation of paint], dilute the fluorinated oil-resistant agent with water using an oil-resistant fluorinated oil-resistant agent (trade name: AG-530, manufactured by Asahi Glass Co., Ltd.) containing a perfluoroalkyl group having a carbon chain length of 8 or more. Thus, a water- and oil-resistant paper of Comparative Example 2 was obtained in the same manner as in Example 3 except that the coating material was prepared and the aging treatment was not performed.

(Comparative Example 4)
In Example 1, a water- and oil-resistant paper of Comparative Example 4 was obtained in the same manner as in Example 1 except that the coating material was infiltrated and adhered to a solid content of 0.2 g / m ² .

  About each sample of said Example 1, 2, 3, 4, 5 and 6 and Comparative Examples 1, 2, 3, and 4, oil resistance, air permeability resistance, and water repellency were measured. These measurement results are shown in Table 1. Next, the measurement method will be described.

(1) Oil resistance Measured by TAPPI UM 557 “Repelency of Paper and Board to Grade, Oil, and Waxes (Kit Test)”. Since the oil resistance of water-resistant and oil-resistant paper using a fluorine-based oil resistant agent currently on the market is grade 5 or higher, the oil resistance level that does not cause problems in general use is grade 5 or higher.

(2) Air permeability resistance Measured according to JIS P 8117: 1998 “Paper and paperboard—Air permeability test method—Gurley tester method”. The value of the air permeability resistance indicates the time required for 100 ml of air to pass through a certain area. Therefore, it shows that air is hard to pass, so that the value of air permeability resistance is large. The air resistance of 50 seconds or less was regarded as a practical level.

(3) Water repellency JAPAN TAPPI Paper pulp test method no. 68: 2000 "Paper and board-water repellency test method". When the water repellency is R4 or higher, the water repellency of the paper can be clearly confirmed visually. Therefore, the water repellency of R4 or higher, which does not cause a problem in general use, was set to a practical level.

In Examples 1, 2, 3, 4, 5 and 6, since a fluorine-based oil resistant agent having a carbon chain length of 6 was used and the amount of fluorine oil-resistant agent adhered was 0.3 g / m ² or more, temperature aging was performed. In both cases, the oil resistance is grade 5 or higher, the air permeability resistance is 50 seconds or less, and the water repellency is R4 or more.

  In Comparative Example 1, a fluorinated oil resistant agent having a carbon chain length of 6 is used and no aging treatment is performed. However, the water repellency is R2, which is not a practical level for water-resistant oil-resistant paper for foods. It was.

  In Comparative Examples 2 and 3, a fluorine-based oil resistant agent having a carbon chain length of 8 or more was used and no aging treatment was performed, but all were good with respect to oil resistance, air resistance, and water repellency. It was of a practical level as water and oil resistant paper for food. However, off-gas is generated, and global environmental loads and safety must be considered.

In Comparative Example 4, the aging treatment was performed using a fluorine-based oil resistant agent having a carbon chain length of 6. However, the oil resistance and water repellency are low because the adhesion amount is 0.2 g / m ^2. It was found that it could not withstand practical use as food and water and oil resistant paper.

  In addition, even when a fluorine-based oil resistant agent having a carbon chain length of 5 is used as in the above examples, the oil resistance is grade 5 or higher, the air resistance is 50 seconds or less, and the water repellency is R4 or more. A practical level of water and oil resistant paper is obtained.

Claims (6)

In a water- and oil-resistant paper in which a fluorocarbon oil-containing agent containing a perfluoroalkyl compound is infiltrated and adhered to a base paper mainly composed of porous fibers,
The perfluoroalkyl compound is a compound having only a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group, and the adhesion amount of the fluorine-based oil proofing agent is 0.3 g / m ² as a solid content. A water- and oil-resistant paper, which is as described above, and is further subjected to a temperature aging treatment at 40 ° C. or more for 3 days or more after drying the base paper impregnated with the fluorine-based oil resistant agent. ^2. The water and oil resistant paper according to claim 1, wherein the adhesion amount of the fluorinated oil resistant agent is 2 g / m ² or less as a solid content. The oil resistance specified in TAPPI UM 557 “Repellency of Paper and Board to Grade, Oil, and Waxes (Kit Test)” is 5th grade or higher, and JIS P 8117: 1998 “Paper and Paperboard—Permeability Test Method”. -The air resistance specified in the "Gurley Tester Method" is 50 seconds or less, and the JAPAN TAPPI paper pulp test method No. 68: 2000 The water and oil resistant paper according to claim 1 or 2 , wherein the water repellency specified in "Paper and paperboard-water repellency test method" is R4 or more. In a water- and oil-resistant paper in which a fluorocarbon oil-containing agent containing a perfluoroalkyl compound is infiltrated and adhered to a base paper mainly composed of porous fibers,
The perfluoroalkyl compound is a compound having only a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group, and the adhesion amount of the fluorine-based oil proofing agent is 0.3 g / m ² as a solid content. A water- and oil-resistant paper which is as described above, and is subjected to a temperature aging treatment until condition 1 is satisfied after the base paper to which the fluorine-based oil-resistant agent has been impregnated and dried is dried.
(Condition 1) The oil resistance specified in TAPPI UM 557 “Repelency of Paper and Board to Grade, Oil, and Waxes (Kit Test)” is 5th grade or higher, and JIS P 8117: 1998 “Paper and board-transparent” The air permeability resistance defined by “Temperature Test Method—Gurley Tester Method” is 50 seconds or less, and JAPAN TAPPI Paper Pulp Test Method No. 68: 2000 “Paper and paperboard—water repellency test method” has a water repellency specified by R4 or more. A process of making a base paper mainly composed of porous fibers;
Infiltrating the base paper with a fluorine-based oilproof agent containing a compound having only a perfluoroalkyl group having a carbon chain length of 6 or less as a perfluoroalkyl group from at least one side of the base paper;
Drying the base paper, and attaching the fluorine-based oilproof agent to the base paper as a solid content in an amount of 0.3 g / m ² or more;
Performing a temperature aging treatment for 3 days or more at 40 ° C. or higher;
A method for producing a water- and oil-resistant paper, characterized by comprising: 6. The method for producing water- and oil-resistant paper according to claim 5 , wherein the fluorine-based oil resistant agent is allowed to penetrate into the base paper by a coating machine attached to a paper machine.