KR890000997B1 - Method for preparing insulating paper of vulcanized fiber - Google Patents

Abstract

The method is such that the kraft pulp rolled up on a roller is passed through a vessel containing an impregnating agent including concentrated zinc chloride added with acryl emulsion and synthetic latex solution. The impregnating solution comprises 75 wt.% zinc chloride, 7-8 wt.% acryl emulsion and 0.5-1.0 wt.% synthetic latex and mainains temp. at 60 degree C for impregnating the kraft pulp.

Description

Insulation Paper Manufacturing Method of Balkanized Fiber

The present invention is a balkanized fiber having high electrical insulation and excellent dielectric breakdown strength through a container of an impregnant in which an acrylic emulsion zone solution and a synthetic latex solution are added to a zinc chloride solution in which kraft pulp (papermaking paper) concentrated in a roller is added. It relates to a manufacturing method.

Conventionally, cotton or wood pulp (also used as cotton rag fibers) and coniferous pulp and hardwood pulp are used as papermaking in a single batch method through a container containing zinc chloride or aluminum chloride as an impregnating agent. Balkanized fibers were prepared in a continuous manner. In the manufacturing method, zinc chloride is an organic industrial material, swelling and exchanging, dissolving at 71-73% by weight, impregnating paper at 60-70 ℃, compressing with roller, and excess zinc chloride. Remove solution, ammonium salt, calcium salt, iron salt, etc., and keep aged at 27-50 ℃ for 30-60 minutes, wash the paper with pure water, and then dissolve by adding strong alkali of sodium hydroxide or potassium hydroxide to water tank. The paper is immersed in the solution and washed.

This is achieved by neutralizing metal oxides or non-fibrous lignin organic substances or strong acid hydrochlorides or sulfates in the fiber solution dissolved by zinc chloride or strong acid, which was removed by pressing with a roller to remove excess zinc chloride. Acid salts can be cleaned quickly because the pH changes to neutral. The dried Balkanized fiber board is dried 2-3 days at room temperature in the air, pressurized with 90 ° C heat using a heat press to make a finished product. do.

In addition, as a continuous method, the paper itself is wound on several rollers, aged with batch chemicals using a calender, washed with water, and dried by washing. Make a product through This is a method of producing a continuous fiber from papermaking to a product, which has been used to produce thin fibers, usually 0.25 mm to 1.8 mm in thickness.

As mentioned above, when the batched and continuously manufactured balkanized fiber boards are dilute in the water bath during the manufacturing process, zinc hydroxide precipitates on the fiber and is difficult to remove. Not only was it degrading the strength of the product, it was also likely to break well, it was used only in limited applications and was not available for high electrical insulators.

In order to reinforce such drawbacks, the present invention adds an acrylic emulsion zone solution to the zinc chloride solution to increase wear resistance, oil resistance, and electrical insulation, thereby improving fracture strength, and adding synthetic latex (SBR ratex) to shrinkage, bending resistance, Excellent impact resistance and water content and ash content is also reduced as much as possible to invent a method for producing a good Balkan nitrided fiber board as described the manufacturing method as follows.

After adding 7-8% by weight of acrylic emulsion solution to 73% by weight zinc chloride, 0.5-1.0% by weight of synthetic latex was added to zinc chloride to form a edification bath (copolymerizing acrylic emulsion and synthetic latex to zinc chloride). Solution) When impregnated with kraft pulp while maintaining the temperature of the refining bath, the paper pulp is swelled while dissolving a certain amount of cellulose in the paper, forming OH bonds between the chemical solution copolymerized with zinc chloride. As the enlightenment takes place. At this time, the room temperature is to maintain a temperature of 18 ℃ and no ventilation. When the reaction solution is pressed with a roller, excess zinc chloride and copolymerized solution are removed, but metal salts, strong salts (hydrochlorides) contained in balkanized fiber insulation boards, or lignin contained in the papermaking process are placed on the fiber boards. It has it. To remove this, first wash with pure water, and then again with strong alkaline aqueous solution such as sodium hydroxide or potassium hydroxide, neutralized to give a clean product that is not dried.

When the cylinder dryer is heated to 90-100 ℃ and completely dried, pressurized with a hot plate press to produce a smooth and beautiful balkanized fiber insulating board. The test analysis results of the Balkanized fiber board manufactured in this way are as follows.

As described above, the Balkanized fiber board is particularly emphasized as an electric insulator, and is used in an electric motor part or other parts requiring strong electric insulating properties, and the acrylic emulsion itself acts as a binder, thus providing an adhesive layer as an excellent adhesive. It is better to have a good safety without cracking or cracking phenomenon, and particularly good dielectric breakdown strength has the useful effect of being used as insulating paper for generators, transformers, switchgear, various motors.

EXAMPLE

[1st process]

After adding 7-8% by weight of an acrylic emulsion solution to 73% by weight of zinc chloride, 0.5-1.0% by weight of synthetic latex was added to the zinc chloride solution to form a correction bath.

Second Process

Kraft pulp wound in several rollers is wound by impregnating the refining bath while maintaining the temperature of the refining bath at 60 ° C. Swelling and entrainment occurs. At this time, the room temperature is maintained at 18 ℃.

[Third process]

The reacted solution is pressed into a compression roller to remove excess zinc chloride and copolymerized solution. At this time, the metal salt, strong acid salt (hydrochloride), or lignin contained in the balkanized fiber insulating board remain in the fiber board.

[4th process]

In order to remove the solution that was not completely removed in the third step, first wash with pure water, and then again with strong alkaline aqueous solution such as sodium hydroxide or potassium hydroxide to neutralize and give a clean product that is not dried.

[5th process]

When the fiber board is not dried, it is completely dried by applying heat of 90-100 ℃ in a cylinder dryer, and then pressurized by a hot plate press to produce a smooth and beautiful balkanized fiber insulation board.

Claims (1)

A method of manufacturing insulating paper for balkan fibers prepared by incorporating a concentrated zinc chloride impregnating agent, the method comprising: preparing an insulating paper for balkan-fiber fibers prepared by adding a solution obtained by copolymerizing acrylic emulsion and synthetic latex to the zinc chloride solution.