JP2007002347A - Processing stock paper for impregnation and impregnated paper for processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a processing stock paper for impregnation suitable for producing impregnated paper for processing, having a high 3-dimensional processing aptitude, and the impregnated paper for processing obtained from the processing stock paper for impregnation. <P>SOLUTION: This impregnated paper for processing is obtained by obtaining the processing stock paper for impregnation having ≤10 sec Stockigt sizing degree specified by JIS P 8122, ≥18% tensile elongation at break in moist time in lengthwise direction and ≥8% in transverse direction, and ≥0.20 km breaking length in moist time in lengthwise direction, and impregnating a resin on the processing stock paper for impregnation by <50 wt.%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an impregnated processing base paper suitable for producing a processing impregnated paper having high three-dimensional processing suitability, and a processing impregnated paper manufactured from the impregnated processing base paper.

Conventionally, impregnated paper in which a base material made of paper or nonwoven fabric made of 100% pulp is impregnated with resin or wax is known (for example, see Patent Document 1). The impregnated paper impregnated with these resins and waxes can impart water resistance, oil resistance, strength and flexibility to the paper by impregnating chemicals to be impregnated, and are used in various applications. For example, by impregnating a base material with latex-based resin to give folding strength, water resistance, etc. to paper, posters, printed materials such as maps, packaging materials for fats and oils, adhesive tape base paper and dust-free paper It is used for corrugated cardboard, which has been improved in suitability for high moisture content such as frozen foods and fruits by impregnating a base material with wax. In addition, it is also used for laminates, electrical insulating papers and the like produced by laminating impregnated paper impregnated with phenolic resin on a base material and hot pressing.
JP 2004-250615 A

  The impregnated paper may be used as a paper container or a decorative board. In applications involving such deformation or deformation along complicated surface shapes such as curved surfaces, impregnated papers are required to have high three-dimensional processability and high elongation characteristics may be required. Since the paper made of the material has a small elongation, the actual condition is that the impregnated paper based on the paper made of natural pulp could not be used.

  On the other hand, as paper having high elongation characteristics and high three-dimensional workability, there is, for example, stretched paper manufactured by a manufacturing method disclosed in Japanese Patent No. 3407114. Paper containers made of stretched paper often require oil resistance and water resistance, and in many cases, a laminate of stretched paper is used. However, although the laminate has oil resistance and water resistance to the paper surface, it does not replace the impregnated paper because it has no effect on the penetration from the cross section.

  In view of the above points, the present inventors have conducted intensive research on processing-impregnated paper having high three-dimensional processing suitability. As a result, the advantages of conventional impregnated paper are not impaired, and processing paper having high elongation characteristics that stretched paper has. The present inventors have found an impregnated processing base paper capable of producing an impregnated paper and a processing impregnated paper manufactured from the impregnated processing base paper.

  An object of the present invention is to provide an impregnated processing base paper suitable for producing an impregnated paper for processing having high three-dimensional processability, and an impregnated paper for processing obtained from the impregnated processed base paper.

  In order to solve the above problems, the impregnated paper for processing according to claim 1 has a Steecht sizing degree defined by JIS P 8122 of 10 seconds or less and a tensile elongation at break of 18% or more in the longitudinal direction when wet. It is characterized by being 8% or more in the transverse direction and a tearing length when wet of 0.20 km or more in the longitudinal direction.

  According to the processing base paper for impregnation according to claim 1 configured as described above, since the Steecht sizing degree defined in JIS P 8122 is 10 seconds or less, the resin is uniformly impregnated in the paper layer. . In addition, since the tensile elongation at break when wet is 18% or more in the vertical direction and 8% or more in the horizontal direction, the three-dimensional workability that can withstand practical use can be maintained. Further, since the tearing length when wet is 0.20 km or more in the vertical direction, it is possible to effectively prevent the processing base paper for impregnation before drying in the process of impregnating the resin.

  The impregnated processed base paper according to claim 2 is manufactured from the stock obtained by blending the impregnated processed base paper according to claim 1 with a wet paper strength agent in a solid content of 0.01 wt% to 1.0 wt%. It is characterized by being.

  According to the processing base paper for impregnation according to claim 2 configured as described above, the wet paper strength agent is produced from a paper stock containing 0.01 wt% or more and 1.0 wt% or less of the solid content of the wet paper strength agent. Therefore, the breaking length when wet can be set to a sufficient target strength.

  The impregnated paper for processing according to claim 3 is characterized in that the impregnated processed base paper according to claim 1 or 2 is impregnated with less than 50% by weight of resin with respect to the impregnated processed base paper. .

  According to the processing-impregnated paper according to claim 3 configured as described above, the processing-impregnated paper having high elongation characteristics can be obtained.

  The impregnated paper for processing of the present invention obtained by impregnating the processed base paper for impregnation of the present invention with a resin has high elongation characteristics and high three-dimensional processability. Therefore, for example, if it is used for a decorative board, a printed wiring board, etc., what can be used only on a plane until now can be used also for complicated shapes, such as a thing with a curved surface and an unevenness | corrugation. In addition, when used in paper containers, etc., it is possible to obtain oil and water resistance superior to conventional laminated paper, as well as to modify the weakness of stretch that is a drawback of stretched paper. It becomes possible.

Hereinafter, the best mode for carrying out the present invention will be described.
The processed base paper for impregnation of the present invention has a Steecht sizing degree defined by JIS P 8122 of 10 seconds or less, a tensile elongation at break of 18% or more in the longitudinal direction, and 8% or more in the transverse direction. The breaking length at the time is 0.20 km or more in the longitudinal direction.

  As described above, it is essential that the processed base paper for impregnation of the present invention has a Steecht sizing degree of 10 seconds or less. By setting the Steecht sizing degree to 10 seconds or less, the resin can be uniformly impregnated into the paper layer. If the Steecht sizing degree is longer than 10 seconds, it becomes difficult to uniformly impregnate the resin into the paper layer.

  In addition, the impregnated processed base paper of the present invention must have a breaking elongation when wet of 18% or more in the vertical direction and 8% or more in the horizontal direction. The term “wet” as used herein refers to a state after the processed base paper for impregnation is immersed in water for 10 minutes. In the present invention, stretched paper is used as an impregnated processing base paper for impregnating the resin. However, the stretched paper is stretched by the impregnating liquid at the time of impregnation with the resin, and loses the stretch properties of the original stretched paper. As a result of intensive studies by the present inventors, if the elongation at break when wet is 18% or more in the vertical direction and 8% or more in the horizontal direction, the impregnated paper for processing after impregnation is three-dimensionally processed enough to withstand practical use. It was found that suitability was maintained.

  Furthermore, the processing base paper for impregnation of the present invention is also essential in the present invention that the breaking length when wet is at least 0.20 km in the longitudinal direction. In the present invention, stretched paper is used as the impregnating base paper used for impregnation, and the stretched paper is preferably stretched paper produced by the production method disclosed in Japanese Patent No. 3407114. The stretched paper produced by the manufacturing method of Japanese Patent No. 3407114 has characteristics such as excellent three-dimensional processing suitability because it can give a stretch property higher than that of the stretched paper so far.

  However, as a disadvantage of the production method, there is a property that the breaking length decreases as the elongation property is increased. When the tear length is small, the disadvantage is that the processed base paper for impregnation in the state before drying during the resin impregnation process is torn. As described above, the breaking length of the impregnated processed base paper when wet is at least 0.20 km in the longitudinal direction. This tear length is lower than that of the base material of ordinary impregnated paper. This is because the base paper for impregnation of the present invention is stretched paper, which is the cause of tearing in the process of resin impregnation due to stretch characteristics. This is because it absorbs external force. However, when the tearing length when wet is less than 0.20 km, tearing during impregnation increases. This is thought to be because the strength of the base paper for processing cannot compensate for the force beyond the absorption due to the elongation characteristics.

  In the impregnated processed base paper of the present invention, the tearing length when wet is preferably 0.20 km or more in both length and width.

  Further, in order to make the impregnated processed base paper of the present invention have a target breaking strength when wet, the impregnated processed base paper has a wet paper strength agent in a solid content of 0.01% by weight or more and 1.0% by weight. It is preferable to produce from a stock containing less than 1%. If the blending amount of the wet paper strength agent is less than 0.01% by weight, there is a possibility that the target sufficient tearing length at the time of wetness may not be obtained. Cause failure.

  The wet paper strength agent that can be used in the present invention may be those commonly used, and examples thereof include polyamide resin, melamine resin, urea resin, glyoxal-modified polyacrylamide, polyamine resin, and polyethyleneimine. Of these, good results were obtained with polyamide resin in the present invention.

  The impregnated paper for processing of the present invention is obtained by impregnating the impregnated processed base paper of the present invention with a resin in an impregnation amount of less than 50% by weight. The amount of impregnation refers to the dry weight of the impregnated resin in the total dry weight of the impregnated paper for processing after impregnation.

  The reason why the impregnation amount of the impregnated processing base paper is less than 50% by weight is that if the impregnation amount exceeds 50% by weight, the load applied to the environment when the processing impregnated paper is used or discarded after being used or incinerated. Since it becomes high, it is not preferable. Further, the impregnation amount of the resin is desirably 3% by weight or more. If the impregnation amount is 3% by weight or more, the processed impregnated paper has sufficient stiffness.

  There are no particular limitations on the type of resin impregnated into the impregnated processed base paper, impregnation means and apparatus. For example, as a kind of resin, melamine resin, phenol resin, polyester resin, silicone resin, epoxy resin, rubber latex, resin latex and the like which are generally used for impregnated paper are impregnated. As long as it has physical properties that can be used, it can be appropriately selected according to the final application.

  Further, as a means for impregnating the resin, for example, a method of continuously producing impregnated paper by an impregnation apparatus such as a pre-wet method, a float method, a doctor bar method or the like may be used. A method may be used in which processing base paper is subjected to processing such as molding in advance, and the processed base paper is impregnated with resin. Or you may use the method of shape | molding what was impregnated with resin before drying, and drying the thing in the shape | molded state.

  Further, the amount of resin impregnation can be determined within the above range from the function and cost required for the final application.

  The impregnated paper for processing has high elongation characteristics and can be used for applications that require high three-dimensional processing suitability, such as paper containers, decorative boards, and wallpaper.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this.

[Example 1]
A mixture of hardwood kraft pulp and softwood kraft pulp in a ratio of 7: 3 was used. A wet paper strength enhancer (polyamide / epichlorohydrin resin, 0.4% by weight of pulp) is mixed with this pulp to produce wet paper on a long net paper machine, and this wet paper is made of a hard substance and has ribs on its surface. And a shrinkage imparting device comprising a hard roll made of a soft substance and rotating at a slow speed, and having a smooth surface and a slow roll. Stretched paper with an amount of 80 g / m ² was obtained. The obtained stretched paper was immersed in water for 10 minutes and then measured for elongation at break and length (measured by the method specified in JIS P 8113). As a result, the tensile elongation at break when wet was 20% in the longitudinal direction and the transverse direction. At 10%, the breaking length was 0.26 km in the vertical direction and 0.20 km in the horizontal direction.

[Comparative Example 1]
A stretched paper obtained in the same manner as in Example 1 except that the difference in peripheral speed in the shrinkage imparting device was treated at 35% was used as Comparative Example 1. The obtained stretched paper had a tensile elongation at break of 28% in the vertical direction and 12% in the horizontal direction, and a breaking length of 0.19 km in the vertical direction and 0.17 km in the horizontal direction.

[Comparative Example 2]
A stretched paper obtained in the same manner as in Example 1 except that the difference in peripheral speed in the shrinkage imparting device was treated at 18% was used as Comparative Example 2. The resulting stretched paper had a tensile elongation at break when wet of 17% and a lateral direction of 7%, and the breaking length was 0.31 km in the vertical direction and 0.24 km in the horizontal direction.

[Comparative Example 3]
A mixture of hardwood kraft pulp and softwood kraft pulp in a ratio of 7: 3 was used. A wet paper strength enhancer (polyamide / epichlorohydrin resin, 0.4% by weight of pulp) was blended with this pulp to obtain a base paper of 80 g / m ² using a long net paper machine. When the obtained base paper was wet, the breaking elongation was 4% in the vertical direction and 6% in the horizontal direction, and the breaking length was 1.0 km in the vertical direction and 0.7 km in the horizontal direction.

[Preparation of impregnated paper and evaluation of suitability for impregnation]
To the stretched paper obtained in Example 1 and Comparative Examples 1 to 3, 90 parts by weight of a water-dispersed styrene acrylic resin copolymer (trade name: EK61, manufactured by Seiden Chemical Co., Ltd.) and a water-dispersed wax emulsion ( (Product name: EW1000, manufactured by Futaba Chemical Co., Ltd.) 10 parts by weight of solid content is mixed to form a resin liquid, which is impregnated with a tab-type table impregnator so that the impregnation amount is 20% by weight. An impregnated paper was prepared. And the processability at the time of impregnation (occurrence | occurrence | production of the tear with a wet paper etc.) was evaluated. In the evaluation, “No” indicates that tearing with wet paper did not occur, and processing suitability during impregnation was good, and “Tearing with wet paper” occurred and processing suitability during impregnation was poor. Was marked “x”.

[Formability evaluation]
The obtained impregnated papers of Example 1 and Comparative Examples 1 to 3 were molded into a round plate having a diameter of 180 mm and a depth of 20 mm, and the moldability (whether or not cracking or tearing occurred) was evaluated. The evaluation was that the molded round plate was not cracked or torn, and the moldability was good, and the molded round plate was cracked or torn. The moldability was poor. "X" was used.

  As shown in Table 1, Example 1 and Comparative Example 1, which have high tensile elongation at break when wet, have high three-dimensional processability even after resin impregnation, which is impossible with conventional impregnated paper. Can be processed easily. However, in Comparative Example 1, as a result of giving a high elongation at break, the tearing length was reduced, so that handling was difficult, such as tearing occurred during resin impregnation. Further, in Comparative Examples 2 and 3, since the tensile elongation at break was small, the moldability was poor.

Claims (3)

  The Steecht sizing degree specified in JIS P 8122 is 10 seconds or less, the tensile breaking elongation when wet is 18% or more in the longitudinal direction, and 8% or more in the transverse direction, and the breaking length when wet is longitudinal. A base paper for impregnation characterized by being 0.20 km or more.   The impregnated processed base paper according to claim 1, wherein the base paper is manufactured from a stock containing a wet paper strength agent in a solid content of 0.01 wt% or more and 1.0 wt% or less.   An impregnated processed paper according to claim 1 or 2, wherein the impregnated processed base paper is impregnated with a resin in an amount of less than 50% by weight.