KR870001395B1 - The method of preparing vulcanized fibre - Google Patents

Abstract

Vulcanized fibre is prepd. from kraft pulp. Thus, opt. coloured kraft pulp contg. 7-15 wt.% of resin powder is immersed into a gelatinization compn. contg. ZnCl2(90%) and HCl in a 9:1 ratio at 25≰C and roll-stacked to yield drafting paper. The paper is treated with 0.5% alkali soln. contg. 90 wt.% KOH based on the weight of HCl. The decolorized paper is washed, dried, and pressed at 90≰C. The pressed paper contg. 70% moisture is coated with paint to give the final product.

Description

Method for manufacturing vulcanized fiber

The present invention relates to a novel process for the manufacture of vulcanized fibers.

Preferably, the present invention adds 7-15 wt% of rosin powder 1 to known kraft pulp, and is based on a paper pulp made of conventional zinc chloride and hydrochloric acid. Was added to form a refining bath, heated to room temperature, and kraft pulp was immersed in it, and then laminated and dried to a constant thickness, immersed again in a strong alkaline aqueous solution, washed with water and dried under pressure to form a hot press. It is characterized by pigment coating on the surface.

Examples of strong alkalis include alkali metal hydroxides or alkaline earth hydroxides, and preferably sodium hydroxide or potassium hydroxide.

In the conventional method of manufacturing balkanized fiber, the pulp made by using the cotton wool is usually used in zinc chloride solution, copper ammonia solution, sulfur phase solution, or aluminum chloride solution in a rehabilitation bath, and then washed with saline solution. The vulcanized fiber is prepared by extracting and diluting and removing acid or metal salts impregnated into the pulp while immersing in water for 1 to 5 days through the refining bath. In other words, a hard water-resistant paper or paperboard made by treating with zinc salt is a method of producing a paper or paperboard, for example, by dipping a raw paper in a thick zinc chloride solution, and then washing it with water or completely washing it with water or drying it. During drying.

At this time, the fiber base paper is required to have excellent absorbency, high chemical purity, uniform degree of polymerization of cellulose, and no paper and harmful substances.

However, the above known method has a long working time and does not completely remove impurities impregnated in the pulp, so that the strength of the fiber is unnecessary so that it is easily broken when used, and only black and white fibers can be manufactured so that the color varies. I couldn't.

The reason for this is that the chemical used in the bathing bath is a salt of strong acid such as hydrochloride or sulfate, and the color of the pulp turns black, and even when washed with salt and water, metal oxides or non-fibrils lignin, etc. Only organic materials are washed and the color of discolored fiber solution should be washed for a long time without reduction. In addition, in the conventional process, there is a complicated process that requires washing with a salt bath and water, so that mass production is difficult and vivid colors cannot be obtained.

The present inventors invented the patent application number 80-4342 (published October 10, 1981. Publication No. 81-1282, Patent Registration No. 11088) to solve this conventional drawback. That is, when about 0.5% of potassium hydroxide or sodium hydroxide was immersed in 90% by weight of the hydrochloric acid solution, and when immersed in the rehabilitation bath, the excess acid or metal ion impregnated in the pulp was completely neutralized and discolored into a strong acid salt. The color is neutralized by alkaline neutralization to reduce the color back to its original color and shorten the washing time without using the salt bath to shorten the manufacturing time and reduce the color of the pulp that has turned into a strong acid. I am doing it.

However, since the method of Patent No. 11088 has a strong water absorption ability, it absorbs a large amount of chemicals unnecessarily, thus increasing the consumption of chemicals, resulting in uneconomical costs, and also increasing the production cost because it takes a relatively long time to wash the chemicals absorbed in the core. It is a factor, and the finished product is still hygroscopic, its weakness is weak.

As a result of continuing research to solve these drawbacks, the present inventors added rosin powder to kraft pulp that does not adversely affect acid, resulting in weak hygroscopicity, preventing unnecessary chemical loss and strengthening the product's own durability. It was also found to be easy, and the present invention was completed by protecting the color change from ultraviolet rays by surface pigment coating.

It is an object of the present invention to provide a novel method for producing a balkanized fiber.

In particular, the present invention relates to a method for producing a balkanized fiber that suppresses unnecessary chemical consumption by adding rosin powder to kraft pulp, enhances the durability of the product itself, and facilitates washing with water.

The present invention also relates to protecting the color change of the product by surface pigment coating.

The rosin powder is a powder prepared by using rosin which can be used as a raw material, and the amount of rosin powder added is 7 to 15% by weight based on kraft pulp.

The manufacturing method of the present invention will be described in detail in the following examples.

EXAMPLE

The kraft pulp containing 7-15 wt% of rosin powder was immersed in a kneading bath in which kraft pulp having an arbitrary color was added to a known 90% zinc chloride with hydrochloric acid at a ratio of 9: 1. At this time, the color of the pulp turns black) After passing through, it is wound up to be laminated by a known method, and again immersed in an aqueous solution of 0.5% potassium hydroxide or sodium hydroxide in about 90% by weight relative to the weight of hydrochloric acid. Immerse about 30 minutes per 1mm (the original color is reduced), wash and dry it with water, pressurize it with a heat press at 90 ℃, and pigment the surface at 70% dry state to obtain a finished product.

Compared with the conventional method, the balkanized fiber manufactured as described above has a drastically reduced washing time, and the work is quicker, and the original color changed during passage of the rehabilitation bath when neutralized with alkaline aqueous solution is reduced to its original arbitrary. It can be produced to have the color of, and the pulp tissue is dense by completely removing the acid or metal remaining in the pulp as well as the lignin remaining in the papermaking process than when washed with conventional salt for a long time washed with water again. It is a product that strengthens its durability by keeping the strength that is tightly adhered to it, keeping it strong, and preventing the loss of unnecessary chemicals and removing the hygroscopicity of the finished product. That is, the present invention enhances the durability of the product itself, makes water washing much easier, and can mass-produce a surface pigment coated balkanized fiber at a low production cost.

Claims (1)

In the known method for manufacturing balkanized fiber, a reforming bath in which hydrochloric acid was added at a ratio of 9: 1 to zinc chloride was mixed at 25 ° C., and then immersed in crayon pulp of any color, and then wound and laminated to cut to arbitrary specifications. In the present invention, kraft pulp containing 7-15% by weight of rosin powder was immersed in 0.5% alkaline aqueous solution of about 90% by weight relative to the weight of hydrochloric acid to reduce color, washed with water and dried under pressure with a hot press. And then a pigment coating on the surface in a 70% dry state.