JPS61167099A - Production of chemicals impregnated paper - 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] [Field of Industrial Application] The present invention uses a paper machine for making ordinary paper and paperboard, and uses chemical impregnation to impregnate various chemical solutions such as humectants and bactericides in the paper making process. It concerns the method of manufacturing paper.

[Conventional technology]

Conventionally, the method of impregnating water-soluble chemicals into paper or paperboard (hereinafter referred to as paper) during the papermaking process has resulted in poor chemical yield, contamination of papermaking equipment, and the need for cleaning. Because of this, it causes problems in the paper making of other papers.
Generally, it has been manufactured by using manufactured paper, impregnating it with a chemical solution in a secondary processing machine, and drying it.

[Problem that the invention seeks to solve]

In this way, in order to impregnate paper with chemicals using a secondary processing machine, it was necessary to choose water-absorbent paper, as once dry paper was used, the chemical solution would be difficult to penetrate into the paper. . This is due to the fact that the wood pulp used as a raw material for papermaking is dried during the papermaking process, which causes the pulp fibers to become keratinized.In order to improve the bonding of the fibers in the paper, the wood pulp is further beaten to improve the density of the paper. In particular, for printing and writing paper, where sizing agents are added, the water absorption becomes poor as the water resistance increases, and the basis weight also decreases. As the amount increased, it became more difficult to uniformly impregnate the entire paper layer with chemicals. For this reason, paper materials such as sizeless blotting paper and door paper with good water absorption are used, but they lack rigidity and are not suitable for processing such as printing and box making.

It is used only for special purposes and is manufactured using a secondary processing machine, which inevitably leads to high costs.

Therefore, the applicant of the present invention invented a method of impregnating a chemical solution during the papermaking process, and in particular, a method of obtaining good chemical-impregnated paper even when using a paper web mixed with a sizing agent, and filed patent application No. 163353 in 1983 with constant humidity These problems were solved by filing an application as a method for creating chemical-containing paper, but in order to impregnate the paper web with a certain amount of chemical solution during the papermaking process, K required mixing raw materials, adjusting raw materials, moisture content of the paper, and impregnating chemicals. It was necessary to adequately control and control the concentration, etc.

The present invention aims to provide a method for easily controlling and controlling the amount of impregnating chemicals in a method for impregnating paper with chemicals during the papermaking process.

[Means for solving problems]

In the method of manufacturing chemical-impregnated paper by impregnating a chemical solution in the papermaking process, the present invention provides a method for impregnating raw material papermaking pulp with a chemical solution into wet paper that is dehydrated and dried at a paper web moisture content of 15 to 45 weight St. This is a production method in which the amount of chemical impregnation is adjusted by changing the amount of sizing agent added to the raw material pulp.

[Effect]

By changing the amount of sizing agent added to the raw pulp, if the type of chemical and MM are constant, the amount of chemical impregnation is inversely proportional to the amount of sizing agent added, making it easy to create products with the required chemical impregnation. This is what you get.

〔Example〕

The present invention will be explained according to examples.

Example 1 Paper impregnated with chemicals such as chlorine compounds such as calcium chloride, 1-iron chloride, 2-iron chloride, and lithium chloride was produced.

The mixing ratio of paper raw materials, adjustment method, target weightage, paper moisture during impregnation, etc. are determined by following the papermaking conditions shown below, using a Fourdrinier multi-tube paper machine, and using chemicals during the papermaking process. The solution was impregnated.

[Papermaking conditions]

(1) Pulp blend NBKP 50% LBKP 50% (2) Addition amount of sizing agent 0.02 to 0.20 inch (3
) Aluminum sulfate addition amount 1.0 Chi (4) Target basis weight 270 f, Taka (5
) Moisture of paper during chemical impregnation: Approximately 30 cmNote, 1.
NBKP is softwood kraft pulp, and LBKP is hardwood kraft pulp.

2. All values are expressed as weight percentages.

3. The amount of sizing agent and aluminum sulfate added is expressed as a weight percentage relative to pulp (solid content).

4. Freeness is measured in accordance with JIS, R8]21 after beating the pulp with the above blending ratio in accordance with the conventional method.

5. The target basis weight is the basis weight when pulp is made into paper with only the addition of sizing agent and sulfuric acid and dried.

During papermaking, the amount of sizing agent added to the raw material pulp is adjusted from 0.02 to 0.20! The concentration of the impregnated chemical solution was varied from 10 to 40% by weight to obtain chemical impregnated paper, and the content of each chemical was analyzed and the results are summarized in Table 1.

Ao, 1. Since the iron chloride is saturated at 38.5% by weight, the 40% weight is omitted.

2. The size addition rate is expressed in relation to the pulp weight, and the impregnating solution concentration is expressed in weight % when the chemical is dissolved in water.

As is clear from the above results, it was found that chlorine compounds exhibit the same amount of chemical impregnation at the same concentration if the size amount is constant, and when the correlation coefficient was investigated, it was found that )' = 0.078 ax ' Here, X... Size addition rate (vs. valve weight qb) y.
...... Chemical content (relative to product weight 1) a...
・It was found that it indicates the concentration of impregnating chemicals (heavy electric current). That is, when impregnating a product with a chlorine compound, if the set chemical content is known, a product having the desired chemical content can be obtained by determining the chemical concentration and size addition amount.

Example 2 Sulfuric acid compounds, lithium sulfate, magnesium sulfate,
We manufactured paper containing chemicals such as sodium sulfate.

The papermaking conditions etc. are the same as in Example 1. As in Example 1, the results are shown in Table 2.

Sulfuric acid compounds, like chlorine compounds, show the same amount of impregnation when the size amount is constant, but it has been found that they show different amounts of impregnation from chlorine compounds. When we investigated the relationship between the size addition rate and the impregnating solution concentration, we found that y -0,104ax ',
・・・・Chemical content (% of product weight) a・・・・・・
It was found that the concentration of impregnating chemicals (heavily tchi) was indicated. That is, when impregnating with a sulfuric acid compound, a product having the required chemical content can be obtained by using the above formula different from that for the chlorine compound.

〔Effect of the invention〕

The present invention provides that when paper containing chemicals is produced in the paper manufacturing process, once the desired chemical content is set, the chemical concentration during impregnation and the amount added to the size of the paper can be determined using a calculation formula specific to the chemical. It is possible to obtain a product with little variation in chemical content. Therefore,
This allows for savings in chemicals and stabilization of products.

Claims (1)

[Claims] The amount of sizing agent added to the raw material pulp when impregnating the wet paper with a chemical solution, which is dehydrated and dried to a moisture content of 15 to 45% by weight in the papermaking process where paper and paperboard are made using papermaking pulp as the main raw material. A method for producing chemical-impregnated paper, which comprises adjusting the amount of chemical solution impregnated by changing the amount of chemical solution.