JP2006161180A - Moisture-proof/water-repellent food packaging paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide moisture-proof/water-repellent food packaging paper given by mixing a rayon fiber thereinto, having a Japanese paper-like feeling, and having water resistance. <P>SOLUTION: This packaging paper comprises the food packaging paper which has a basis weight of 9-30 g/m<SP>2</SP>and contains the rayon fiber, wherein the rayon fiber having a size of 0.5-5 dtex and a fiber length of 1-7 mm is mixed into the paper in an amount of 5-70 mass%, a wet paper strength reinforcing agent is internally or externally added to the paper, a wet breaking length (longitudinal) Lw [Lw=(S×10<SP>3</SP>)/(g/9.81), wherein S is a wet tensile strength (kN/m) for an immersion time of 10 min according to JIS P8135; and g is a basis weight (g/m<SP>2</SP>) in a wet state after water is removed by blotting paper according to JIS P8135] is made to be 1.2 km or more, the packaging paper is coated with a water repellent, and a degree of water repellency (JIS P8137) is made to be R7 to R10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture- and water-repellent food wrapping paper, and more particularly to a moisture- and water-repellent food wrapping paper that exhibits water resistance in a food wrapping paper blended with rayon fibers and having a Japanese paper-like texture.

  As a food wrapping paper having a Japanese paper-like texture, one obtained by binding rayon fibers with polyvinyl alcohol (PVA) as a binder is known. This food wrapping paper has good paper-making properties and is relatively inexpensive, so it is often used, but it does not have water resistance, so it cannot be used for applications where there is a risk of getting wet. there were. In addition, when such a food wrapping paper is subjected to a brazing process and imparted water resistance, there is a problem that the surface becomes flat and the texture of the Japanese paper is impaired.

  On the other hand, as wrapping paper having water resistance, those using non-hydrophilic fibers such as polyethylene fiber and polypropylene fiber are known, but because they are non-hydrophilic, paper-making properties are poor and productivity is low. There was a drawback of high cost.

Therefore, the rayon fiber is suspended in a viscose solution as a binder and then made into paper, and then acid-treated, so that the rayon fiber is bound by cellulose obtained by acid-treating viscose, water resistance, and contact with water. It has been proposed to obtain a rayon paper that has the durability and the property of being excellent in biodegradability (see Patent Document 1).
JP-A-9-296387

  However, the rayon paper described in Patent Document 1 requires man-hours for the acid treatment after papermaking and the subsequent post-treatment necessary for the paper making, and it is difficult to stably produce the paper without damaging the properties such as texture. There is a problem that the cost is high and it is difficult to stabilize the quality.

  In view of the above-described conventional problems, an object of the present invention is to provide a moisture- and water-repellent food wrapping paper that is blended with rayon fibers and has a Japanese paper-like texture and water resistance.

The moisture- and water-repellent food wrapping paper of the present invention is a food wrapping paper containing rayon fibers having a basis weight of 9 to 30 g / m ² and having a fineness of 0.5 to 5 dtex and a fiber length of 1 to 7 mm. 5 to 70% by mass, and a wet paper strength enhancer is added internally or externally,
Lw = (S × 10 ³ ) / (g / 9.81)
Where Lw: wet tear length
S: Wet tensile strength (kN / m) Compliant with JIS P8135 Immersion time 10 minutes
g: Basis weight when wet (g / m ² ) Based on JIS P8135, the wet tear length (longitudinal) defined by the basis weight after removing water by blotting paper is set to 1.2 km or more. A water agent is applied, and the water repellency (JIS P8137) is set to R7 to R10.

  According to this configuration, a paper having a wet paper strength with a wet tear strength (longitudinal) of 1.2 km or more, using a raw slurry containing rayon fibers, internally or externally adding a required amount of wet paper strength enhancer. Thus, gravure coating or the like can be applied by using the paper having the wet paper strength, and a paper having a water repellency R7 to R10 can be obtained by stably applying a water repellent with good productivity. It is possible to produce food wrapping paper with the required water resistance by having moisture resistance and water repellency while having a Japanese paper-like texture containing rayon fibers. be able to.

  Further, rayon fibers having a fineness of 0.5 to 5 dtex, preferably 1.1 to 3.3 dtex, and a fiber length of 1 to 7 mm, preferably 3 to 7 mm, are 5 to 70% by mass, preferably 30 to 30%. Since 50 mass% is mix | blended, the food wrapping paper which has required paper strength and water resistance can be obtained, ensuring the desired texture as a Japanese paper-like food wrapping paper.

Further, if the basis weight is less than 9 g / m ² , the strength as a wrapping paper is insufficient, and papermaking properties are deteriorated. If the basis weight exceeds 30 g / m ² , the texture of the wrapping paper is impaired. 30 g / m ² .

According to the present invention, in a food wrapping paper containing rayon fibers having a basis weight of 9 to 30 g / m ² , 5 to 70 mass% of rayon fibers having a fineness of 0.5 to 5 dtex and a fiber length of 1 to 7 mm are blended. The wet paper strength enhancer was added internally or externally to make the wet tear length (longitudinal) 1.2 km or more, and a water repellent was applied to the wrapping paper, and the water repellency was set to R7 to R10. Thus, a food wrapping paper having a Japanese paper-like texture and water resistance can be obtained at low cost.

  Hereinafter, embodiments of the moisture- and water-repellent food wrapping paper of the present invention will be described in detail.

The moisture-resistant / water-repellent food wrapping paper of the present invention is a food wrapping paper containing rayon fibers, which is internally or externally added with a wet paper strength enhancer, and has a wet tear length (length) Lw (Lw = (S × 10 ³ ) / (G / 9.81), where S: wet tensile strength (kN / m) in 10 minutes according to JIS P8135, g: wetness after removing water with blotting paper based on JIS P8135 The basis weight (g / m ² )) is 1.2 km or more, a water repellent is applied to the wrapping paper, and the water repellency (JIS P8137) is R7 to R10.

Depending on the required properties of the food wrapping paper, the papermaking raw material is a blend of 93-22 mass% of pulp raw materials such as NBKP, 5-70 mass% of rayon fibers, and 2-8 mass% of binders such as vinylon binder. It is prepared so as to have a ratio, and is made so that the basis weight is in the range of 9 to 30 g / m ² .

  As a raw material for pulp, NBKP is suitable for obtaining a Japanese paper-like texture, but LBKP may be blended, and other mechanical pulps such as GP, PGW, RMP, TMP, CTMP, CMP, and CGP depending on applications. Waste paper pulp such as DIP can also be blended. As the rayon fiber, those having a fineness of 0.5 to 5 dtex, preferably 1.1 to 3.3 dtex, and a fiber length of 1 to 7 mm, preferably 3 to 7 mm are suitably used.

  Any commonly used wet paper strength enhancer can be applied. For example, “WS4024” (manufactured by Seiko PMC), which is an epichlorohydrin-based wet paper strength enhancer, is preferably used. Moreover, the addition amount is an amount necessary for ensuring the wet tearing length, and the actual addition amount is about 5 to 40 kg / t for the dry pulp / fiber raw material.

As the water repellent, commonly used ones such as paraffin wax can be applied. For example, “WR3908” (manufactured by Seiko PMC, main component paraffin wax, non-volatile content 30%) is preferably used. It is done. The coating amount is an amount necessary to ensure the above-mentioned water repellency. For example, in the case of “WR3908”, it is about 0.5 to 10 g / m ^{2 in} terms of a stock solution. As the coating method, various coating methods such as roll, air knife, blade coating and the like can be applied. According to gravure coating, in addition to the concentration and viscosity of the coating liquid, the cell depth and mesh of the gravure roll are determined. By adjusting, the amount of coating can be easily adjusted, and uniform coating is preferable.

  Next, some examples and comparative examples of the present invention will be described.

Example 1
NBKP (Freeness 380ml CSF) 50% by mass
Rayon fiber (fineness 3.3 dtex, fiber length 5 mm) 45% by mass
Binder (polyvinyl alcohol fiber, melting point 80 ° C., fineness 1.1 dtex, fiber length 3 mm) 5% by mass
6 kg / t of “AD1602” (manufactured by Seiko PMC, solid content 20%) as a sizing agent, and 20 kg / t of “WS4024” (manufactured by Seiko PMC, non-volatile content of 30%) as a wet paper strength enhancer. The paper was made to have a basis weight of 15 g / m ² . Next, the paper was passed through a gravure coating machine, and a 10-fold diluted solution of paraffin wax “WR3908” (manufactured by Seiko PMC, main component paraffin wax, nonvolatile content 30%) was applied at an application amount of 15 g / m ² , Dried food packaging paper.

(Example 2)
A food wrapping paper was obtained in the same manner as in Example 1 except that the blending amount of the rayon fiber was changed to 5% by mass and NBKP was increased by the reduced amount.

(Example 3)
A food wrapping paper was obtained in the same manner as in Example 1 except that the amount of the rayon fiber was changed to 70% by mass and NBKP was decreased by the increased amount.

Example 4
A food wrapping paper was obtained in the same manner as in Example 1 except that the fineness of the rayon fiber was changed to 1.1 dtex.

(Example 5)
A food wrapping paper was obtained in the same manner as in Example 1 except that the fineness of the rayon fiber was changed to 4.4 dtex.

(Example 6)
A food wrapping paper was obtained in the same manner as in Example 1 except that the addition amount of the wet paper strength enhancer (“WS4024” (manufactured by Seiko PMC)) was changed to 5 kg / t.

(Example 7)
A food wrapping paper was obtained in the same manner as in Example 1 except that the addition amount of the wet paper strength enhancer (“WS4024” (manufactured by Seiko PMC)) was changed to 40 kg / t.

(Example 8)
A food wrapping paper was obtained in the same manner as in Example 1 except that the coating amount of the water repellent (“WR3908” (manufactured by Seiko PMC) 10-fold diluted solution) was changed to 5 g / m ² .

Example 9
A food wrapping paper was obtained in the same manner as in Example 1 except that the coating amount of the water repellent (“WR3908” (manufactured by Seiko PMC)) was changed to 10 g / m ² .

(Example 10)
A food wrapping paper was obtained in the same manner as in Example 1 except that the fiber length of the rayon fiber was changed to 7 mm and the basis weight was changed to 9 g / m ² .

(Example 11)
A food wrapping paper was obtained in the same manner as in Example 1 except that the fineness of the rayon fiber was changed to 0.8 dtex, the fiber length was changed to 4 mm, and the basis weight was changed to 30 g / m ² .

(Comparative Example 1)
A food wrapping paper was obtained in the same manner as in Example 1 without adding the wet paper strength enhancer.

(Comparative Example 2)
A food wrapping paper was obtained in the same manner as in Example 1 except that the addition amount of the wet paper strength enhancer (“WS4024” (manufactured by Seiko PMC)) was changed to 4 kg / t.

(Comparative Example 3)
Except for changing the fineness of the rayon fiber to 5.6 dtex, changing the addition amount of the wet paper strength enhancer (“WS4024” (manufactured by Seiko PMC)) to 4 kg / t, and changing the basis weight to 30 g / m ² . In the same manner as in Example 1, a food wrapping paper was obtained.

(Comparative Example 4)
Example except that the blending amount of rayon fiber was changed to 3% by mass and the coating amount of the water repellent (“WR3908” (manufactured by Seiko PMC) 10-fold diluted solution) was changed to 3 g / m ^2. In the same manner as in Example 1, a food wrapping paper was obtained.

(Comparative Example 5)
A food wrapping paper was obtained in the same manner as in Comparative Example 2 except that the fiber length of the rayon fiber was changed to 10 mm and the basis weight was changed to 32 g / m ² .

  About the food packaging paper of the above Examples 1-11 and Comparative Examples 1-5, the said wet tear length and water repellency were measured. Each food wrapping paper was evaluated for water repellent coating properties and texture.

Regarding the coating property of the water repellent agent, it was as follows. ◎: Continuous coating was possible without any problems. ○: Although there was a tendency to be slightly wavy, continuous coating was possible. X: Relative evaluation was performed in four stages, ie, the paper was cut immediately after the water repellent coating and the coating could not be performed.

As for the texture, compared to food-quality paper with high-quality paper, we asked 10 people whether or not it has a texture of Japanese paper. ◎: Has a texture of Japanese paper ○: Has a texture of Japanese paper, but slightly fine paper ×: Evaluation was made in three stages, which is not much different from fine paper, and a large number of evaluations were evaluated for the samples.

上記実施例１〜１１及び比較例１〜５について、原料の配合量、そのレーヨン繊維の繊度と繊維長、湿潤紙力増強剤の添加量、坪量、撥水剤の塗布量、及び上記測定値と記評価結果を表１に示した。

About the said Examples 1-11 and Comparative Examples 1-5, the compounding quantity of a raw material, the fineness and fiber length of the rayon fiber, the addition amount of a wet paper strength enhancer, a basic weight, the application quantity of a water repellent, and the said measurement The values and the evaluation results are shown in Table 1.

  Examples 1 to 3 are examples in which the blending ratio of the rayon fibers was changed in the range of 5 to 70% by mass. However, the higher the blending ratio of the rayon fibers, the lower the wet breaking length, but the wet The addition of the paper strength enhancer has a sufficient wet tearing length, and the evaluation of the water repellent coating property is good. Further, in Example 2 where the blending amount of rayon fiber is as low as 5% by mass, the evaluation of the texture of Japanese paper is slightly lower than in Examples 1 and 3.

  Example 4 is an example in which the fineness of the rayon fiber is smaller than that of Example 1, and the wet tear length is slightly higher than that of Example 1, while the Japanese paper-like texture evaluation is slightly lower. On the other hand, Example 5 is an example in which the fineness of the rayon fiber is larger than that of Example 1, and the wet tear length is slightly lower than that of Example 1.

  In Example 6, the addition amount of the wet paper strength enhancer was 5 kg / t, which was less than 20 kg / t of Example 1, the wet tear length was 1.3 km, which was lower than 1.5 km of Example 1, and the water repellent property Although the evaluation of the agent coating property is somewhat low, it is a practically satisfactory evaluation. On the other hand, in Example 7, the addition amount of the wet paper strength enhancer is 40 kg / t, which is larger than 20 kg / t of Example 1, and the wet breaking length is 1.8 km, which is higher than 1.5 km of Example 1, Evaluation of water repellent coating properties is also good.

In Example 8, the application amount of the water repellent was as small as 0.5 g / m ² and the water repellency was as low as R7. On the other hand, in Example 9, the application amount of the water repellent was as large as 5.0 g / m ^2, and the water repellency was the highest value of R10.

Example 10 is lower than 15 g / m ² of Example 1 having a basis weight between 9 g / m ^2, made wet breaking length is lower than 1.5km of Example 1 and 1.2km, coatability of the water-repellent agent The evaluation is also slightly lower. On the other hand, Example 11 having a basis weight greater than 15 g / m ² of 30 g / m ² as in Example 1, the wet breaking length is higher than 1.6km and 1.5km of Example 1. Moreover, compared with Example 1, the texture evaluation of a Japanese paper tone is somewhat low because of the large basis weight and the fineness and fiber length of the rayon fiber.

In Comparative Example 1, since the wet paper strength enhancer was not added, the wet tear length was as low as 0.8 km, so that the water repellent could not be applied. In Comparative Example 2, 4 kg / t of wet paper strength enhancer was added, but the wet tearing length was as low as 1.0 km due to the small addition amount, and the water repellent could not be applied. . In Comparative Example 3, the basis weight of Comparative Example 2 was increased to 30 g / m ² , but the wet tear length was slightly increased to 1.1 km, and the coatability evaluation was slightly improved. Since the fineness of the paper is large, the evaluation of the texture of Japanese paper is getting worse.

In Comparative Example 4, the blended amount of rayon fiber is 3% by mass, which is lower than 5% by mass of Example 2, so that the evaluation of the texture of Japanese paper is worse. The coating amount of the water repellent less than 1.5 g / m ² of 0.3 g / m ² as in Example 2, water repellency is also summer low as R6. In Comparative Example 5, the basis weight is 32 g / m ^2, which is higher than that of Comparative Example 3 and the fiber length is long. Moreover, the wet tear length is low, and the applicability evaluation of the water repellent is also poor.

  From the above results, in Examples of the present invention, the food wrapping paper having the required water resistance can be obtained with high paper-making properties by having moisture resistance and water repellency while having a Japanese paper-like texture containing rayon fibers. It can be manufactured with productivity.

Claims (1)

A food wrapping paper containing rayon fibers having a basis weight of 9 to 30 g / m ² , containing 5 to 70% by weight of rayon fibers having a fineness of 0.5 to 5 dtex and a fiber length of 1 to 7 mm, and wet paper Internally or externally adding a force enhancer, the wet tear length (length) defined by the following formula is 1.2 km or more, a water repellent is applied to this wrapping paper, and the water repellency (JIS P8137) is set. Moisture- and water-repellent food wrapping paper characterized by R7 to R10.
Lw = (S × 10 ³ ) / (g / 9.81)
Where Lw: wet tear length
S: Wet tensile strength (kN / m) Compliant with JIS P8135 Immersion time 10 minutes
g: Basis weight when wet (g / m ² ) Basis weight after removing water with blotting paper based on JIS P8135.