JPS5860096A - Production of neutralized decorative paperboard with improved press roll peeling property - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making a neutral decorative laminate base paper with improved press roll releasability.

Decorative laminate base paper is printed or twisted using resin for decorative laminate molding (melamine resin, polyester resin).

(allyl 7 talate resin, etc.) and then press-bonded to a decorative laminate base material 11 made of phenolic core, plywood, hardboard, verticle board, etc. to form a decorative laminate.

For this reason, the main properties required of the decorative laminate base paper include printability, impregnability, and shielding ability to shield the decorative laminate base material 1ii. Furthermore, when the decorative laminate base paper is impregnated with a water-bathable resin such as a decorative laminate molding resin or melamine resin, the decorative laminate base paper needs to have a certain degree of M1 in the aqueous impregnating liquid.

For this reason, decorative board base paper is usually made by adding a wet paper strength agent.

Conventionally, #L acid band resin has been used as a fixing agent for decorative board base paper. In this case, with the diversification of wet paper blur, a neutral paper making method has been developed in which paper is made in a neutral region. In this case, the melamine formaldehyde resin cannot exhibit its effectiveness as a wet paper strength enhancer. This is because the crosslinking reaction of the melamine formaldehyde resin is difficult to proceed in the neutral region. Therefore, polyamide boriamine epichlorohydrin resin is mainly used as a wet paper strength enhancer for neutral decorative board base paper.

The amount of this polyamide polyamine epichlorohydrin resin added varies depending on the amount of additives such as a screening agent (mainly titanium dioxide) and a pigment, and is added so that the decorative board base paper has a wet paper strength above a certain level.

Therefore, if it is necessary to add a large amount of titanium dioxide and/or pigment, etc., it is necessary to add a large amount of polyamide polyamine epichlorohydrin resin and to form the paper by adding more than a certain amount of tohydrin resin.

At 45, part of the surface of the wet paper was removed by the press roll, making it unsuitable for use as a base paper for decorative laminates. In the worst case, the wet paper may adhere to the roll and not be able to be peeled off.

As a result of detailed study by the present inventors to improve this drawback, we found that Il per colloid at pH 7 was 2.5 milliequivalents/
It has been discovered that press roll release properties are improved by using a sub-gram polyamide polyamine epichlorohydrin resin as a wet paper strength agent. The colloid equivalent value as used in the present invention refers to a value determined by a colloid titration method (titration is carried out with N/400 potassium polyvinylsulfonate using toluidine blue as an indicator).

The wet strength enhancing effect of polyamide polyamine epichlorohydrin resins generally increases with colloid equivalent value.

Therefore, in order to impart a certain level of wet paper strength to decorative board base paper, it is not necessary to use wet paper strength enhancers such as colloid and sulfuric acid, but this suppresses problems such as floating seeds and bubbles of raw materials. Therefore, 0 to 10 parts by weight may be added to 100 parts by weight of the valve.

At this time, caustic soda or sodium aluminate can be used as a neutralizing agent to neutralize the system. According to the method of the present invention, neutral decorative board base paper can be stably produced.

When the colloidal equivalent of polyamide epichlorohydrin is outside the range of the method of the present invention, stable production is poor, resulting in partial thickness and thinning of the paper and poor surface properties of the paper.

Downstream The present invention will be explained based on examples.

Example I LBKP adjusted to a freeness of 25°81' (100
The colloid equivalent values at pH 7 are 2.3° and 2.5°, respectively, in parts by weight. 2.8. 8.0 meq/gram of polyamidethane, 20 parts by weight, and sulfuric acid band were added, and the medium tensile strength was approximately 0.6 KgA5mm.

In order to measure the stars that were transferred from the surface of the wet paper to the press roll during papermaking, a knife with a constant blade width was pressed against the press roll for a certain period of time, and the deposits on the press roll surface were collected, completely dried, and weighed. The results are shown in Table 1.

From the table, it can be seen that as the colloidal equivalent value of the polyamide polyamine epichlorohydrin resin increases, the amount that adheres to the press roll increases. Paper obtained using a polyamide polyamine epichlorohydrin resin having a colloid equivalent value of 2.8 milliequivalents/g or more had dotted thinned areas and was unsuitable for use as a base paper for decorative laminates.

Table 1 Example 2 100N parts of LBKP, freeness B
1.8 parts by weight of polyamide polyamine epichlorohydrin resin, and further 80 parts by weight of titanium dioxide,
0.8 parts by weight of a yellow pigment, 0.2 parts by weight of a red pigment, and 0.01 parts by weight of a black pigment were added, and then sulfuric acid was added and then neutralized.

This paper stock was made into a paper having a size of 118,097♀ tsubo using a Fourdrinier paper machine. The amount of t removed from the surface of the wet paper by the press roll during this papermaking process is 0.044 when completely dry.

Fu et al.'s 7'L Nen product had no problems at all as a base paper for decorative laminates 0 Comparative example p) [? A large amount of polyamide polyamine epichlorohydride having a colloidal equivalent value of 8.0 mEq/g was distributed in the paper, making it unsuitable for use as a base paper for decorative laminates.

Patent Applicant Kojin Co., Ltd. Procedural Amendment Document Showa Δ/Her//Month/3■1 Special h1 Office 4f AnA-Isu (1South 1℃名5 Urar!i;i7宸)11 attached power jyu 1;1
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Claims (1)

[Claims] A polyamide polyamine epichlorohydrin resin having a colloidal equivalent value of 2.5 milliequivalents/gram or less at pH 7 is used as a wet paper strength agent.