JP3135651B2 - Production method of base paper for release paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a base paper for release paper of adhesive paper for general adhesive, tape, casting, molding, and food hygiene applications.

[0002]

BACKGROUND ART base paper for release paper are those silicone release agent to the paper coating technique is roughly classified into the following three types. (1) A type in which a thin film of polyethylene is laminated on paper (2) A type in which paper is filled with pigment (mainly clay) coating (3) A type in which paper is coated directly with silicone (3) Is inexpensive and has high marketability. Most of those of the silicone straight coated type, Semigurashin, what is known as glassine paper, generally high freeness pulp (JIS P8121 Canadian Standard Freeness 250ml or more) as a raw material, after paper, strong line It is commercialized by super calendar processing with pressure.

[0003] It like Semigurashin, for calendered glassine base paper for release paper used as the starting material is Ko叩solutions and intensity line pressure in this manner, peeling aptitude after the silicone coating is stable are excellent dimensional There was a disadvantage that the properties were poor. In addition, in the case of this glassine paper type raw material, there is also a problem that the super calendering treatment has to be carried out in a separate step (offline) after being once wound up by a paper machine, resulting in poor productivity.

[0004]

SUMMARY OF THE INVENTION The present inventors have made the present invention to solve the problems of dimensional stability and productivity of such glassine type base paper for release paper.

[0005]

According to the present invention, a Canadian standard type pulp having a freeness of 300 ml or more is coated with polyvinyl alcohol on both sides by 1 to 3 g / m ² on one side and dried and then humidified by steam. those concerning the manufacturing how the release paper for stencil, characterized in that the calendering at 130 ° C. to 150 DEG ° C. to. The freeness of the pulp used in the present invention is
If it is not less than 300 ml, satisfactory dimensional stability cannot be obtained. Polyvinyl alcohol used in the present invention has a polymerization degree of 300 to 2000, and a saponification degree of 70 to 100% can be used.

The adhesion amount of polyvinyl alcohol is 1 to 3 g
/ M ² , and if it is 1 g / m ² or less, sufficient releasability cannot be obtained. Further, even if 3 g or more is applied, further releasability cannot be expected. Further, in order to obtain a sufficient peeling property by the calendering treatment, the heating steam treatment is indispensable. The heating steam treatment is only required to jet a fixed angle from the nozzle parallel to and facing the paper to the paper surface, and the steam adheres to the paper surface to appropriately raise and adjust the temperature and moisture of the paper. Flat 3-13885
Devices described in 2,140399, 169078, 166175, 143511, 138853 can be used.

The calendering treatment is performed at a temperature of 130 to 150 ° C. If the temperature is lower than 130 ° C., satisfactory surface properties and releasability cannot be obtained, and if the temperature is higher than 150 ° C., the durability of the roll deteriorates.
In order to carry out the present invention, it is desirable to use a soft calender method having a special resin roll excellent in heat resistance and pressure resistance. Urethane resin, polyether resin, ebonite rubber is used as the special resin of the soft calender used in the present invention, and the surface strength is 60 to 93 in Shore hardness D.
Are preferred. Further, surface roughness (center line average roughness in accordance with JIS B0601) and air permeability can be used as product management indexes.

In order to obtain good peelability, the surface roughness must be
The air permeability (measured by the JIS P8117 Oken-type air permeability test) is preferably 1.2 μm or less and 30,000 seconds or more. In addition to use in the present invention
The paper preferably has a basis weight of 40 to 150 g / m ² , and high-quality paper, medium-quality paper, or those containing recycled waste paper can also be used. Fillers for internally added to or paper, talc, clay, kaolin, calcium carbonate and the like, can be appropriately used. The further the paper <br/> are dyes, sizing agents, dry strength agents, wet strength agents, can be used as needed fixing agent, additives such as a retention aid.

[0009]

Embodiments will be described below in detail with reference to embodiments. In this example, the following device was used. ○ Polyvinyl alcohol coating Gate roll coater (manufactured by SMT, for research) ○ Calendar treatment Two-stack soft calender with a two-stage soft nip consisting of a combination of chilled rolls and resin rolls (Minami Senju Seisakusho) ○ Heating and humidification Equipment Steam injection (Steam Foil of Aikawa Iron Works Co., Ltd.) on the paper surface on the side that hits the chill roll before each nip

Example 1 Commercially available polyvinyl alcohol (trade name Gosenal T-35) was applied to paper having a basis weight of 75 g / m ² using pulp having a freeness of 350 ml.
0: Nippon Synthetic Chemical Industry Co., Ltd.) 2 g / m ² on one side (4 g /
m ² ) After coating and drying, steam pressure 0.8 kg / cm ² , steam flow 5
Steam was injected at a width of 0 kg / Hr / m and calendered at 150 ° C.

Comparative Example 1 A paper having a basis weight of 75 g / m ² using pulp having a freeness of 200 ml was superposed at 80 ° C. using a test supercalender for research at 80 ° C. so as to have the same peelability as commercially available semi-glassine paper. Calendar processed.

Comparative Example 2 Commercially available polyvinyl alcohol (trade name: Gohsenal T-35)
0: 0.7 g / m ² on one side (1.4 g on both sides)
/ M ²⁾ except that the coating is used the same paper as in Example 1 was treated under the same conditions.

[0013] except that the treated soft calender in Comparative Example 3 100 ° C., using the same paper as in Example 1 was treated under the same conditions.

(Quality evaluation method) Surface roughness: SE-3C type universal surface shape measuring instrument: It was measured by a center line average roughness (μm) according to JISB0601 using Kosaka Laboratory. The smaller the value, the better the surface properties. -Air permeability: Measured with a JIS P8117 Oken type air permeability tester. The larger the value (second), the lower the air permeability.

Dimensional stability: According to J. Tappi No. 27-78,
After the paper test piece was immersed in water for 30 minutes, excess water was removed with blotting paper, and the water elongation (%) was measured by the following equation. L1: Length after immersion L2: Initial length before immersion

Peel strength: A commercially available silicone (trade name: KS 837: manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to a base paper for release paper at a rate of 1 g / m ² with a Meyer bar and dried, and then an adhesive (trade name: S)
K Dyne 801B: manufactured by Soken Chemical Co., Ltd. is applied with a 120 μm applicator, and the surface substrate (general high-quality paper: basis weight 65 g / m ² )
Paste. Further, the peel resistance of this sample having a width of 20 mm immediately after the surface substrate was peeled off with a Tensilon type tensile tester was shown in units of grams (g).

Table

[0018]

As is clear from the table, Example 1 has a low peel strength equivalent to that of Comparative Example 1 corresponding to a conventional semi-glassine paper, having a surface roughness of 1.2 μm and an air permeability of 30,000 seconds or more. And the elongation in water is small and the dimensional stability is very excellent. In Comparative Example 2 in which the coating amount of polyvinyl alcohol was 1 g / m ² or less, and in Comparative Example 3 in which the calendering temperature was 130 ° C. or less, the air permeability was 30,000 seconds or more, but the surface roughness was 1.2 μm or more. peel strength is inferior high peeling aptitude.
Thus, according to the method for producing a base paper for release paper according to the present invention,
In conventional Semigurashin, while maintaining the peel suitability of glassine paper, and at the same time can dramatically improve the dimensional stability, it can produce a base paper for high productivity release paper on-machine
Can be .

Claims (1)

(57) [Claims] 1. A Canadian standard freeness of more than 300ml Pal
Polyvinyl alcohol on both sides of the paper
After coating and drying at 3 g / m ² , it was humidified and heated with steam to 130 g / m ^2.
A method for producing base paper for release paper, wherein the base paper is calendered at a temperature of from 150C to 150C .