JPS59223390A - Deinking agent for regenerating used 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 The present invention relates to a deinking agent used when recycling used paper such as newspapers and magazines. More specifically, the present invention relates to a deinking agent capable of obtaining deinked pulp with high whiteness and a small amount of residual ink when newspapers, magazines, etc. are deinked by a 70-thickening method or a 70-thickening/washing combination method.

Recycling of used paper such as newspapers and magazines has been carried out for a long time, and in the past it was mostly used as a bulking agent, but now due to structural changes in the procurement of raw materials, it is becoming more popular. Waste paper is recognized as an important resource. With the development of deinking technology, it has become possible to obtain deinked pulp that is equivalent to virgin pulp in terms of quality. In particular, deinked newspaper pulp is now being used instead of ground pulp, and its added value has increased. The use of waste paper Nyu is not only a part of raw material measures, but also one of the energy costs of ground pulp and kraft pulp.
It is 15 to 1/8 υ, and is also effective as an energy saving measure. In addition, from the perspective of preserving forest resources and countering urban waste, deinking waste paper can be said to have the advantage of being a dog.

In this way, while the energy-saving deinking process for used paper is increasing, the adhesion between paper and ink has become stronger due to changes in printing technology, printing methods, and printing ink components. It is difficult to remove from the sea waste paper. Under these circumstances, it has become difficult to obtain recycled paper with high whiteness using conventionally known deinking agents.

To separate and remove ink and other impurities from waste paper, alkaline agents such as sodium hydroxide, sodium silicate, sodium carbonate, and sodium phosphate, bleaching agents such as hydrogen peroxide 9-hyposulphite, 9-hypochlorite, etc. EDTA,D
Chemicals such as metal ion sequestering agents such as TPA, NTA, and 5TPP are used, but along with these agents, conventionally known chemical substances used in deinking agents for waste paper recycling include alkylbenzene sulfonates, alkyl sulfates, α-olefin sulfonates, etc. , dialkyl sulfosuccinates, anions such as higher fat 1″) salts + 4″ surfactants, higher alcohol ethylene oxide adducts,
Alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts/fatty acid amide ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, ethylene oxide adducts of fats and oils, higher alcohol ethylene oxide propylene oxide (
Examples include nonionic surfactants such as block or random (block or random) adducts, and amphoteric ionic surfactants such as amine oxides and alkyl betaines. Also, these chemicals and /l? It is also a known fact that the effect can be increased by blending with certain organic saw builders and organic solvents. However, with these chemical substances and their compounds, the deinking efficiency in the flotation process is not necessarily high, and the demand for obtaining recycled paper with high whiteness cannot necessarily be met. For example, fatty acids and soaps that have excellent ink-capturing ability in the flotation process have a drawback that their foaming properties in the flotation process are very low, and that the ink that has coagulated and floated cannot be removed sufficiently.

In addition, anionic surfactants, nonionic surfactants, and zwitterionic surfactants have sufficient foaming properties and ink removal properties from paper in the flotation process, but their ink collection ability is weak and foaming It has the disadvantage that less ink is present on the layer and in the foam layer. As described above, no chemical substance has been found that has both the ability to remove ink from highly foaming paper in the flotation process and the ability to collect ink.

As a result of our earnest efforts to obtain a deinking agent with high deinking efficiency that can meet the demands for technological innovation, the present inventors have succeeded in achieving the above-mentioned results by using a deinking agent for waste paper recycling that contains a certain chemical substance. The inventors have found a way to achieve the objective and have arrived at the present invention.

That is, the present invention provides a deinking agent for recycling waste paper characterized by containing protein.

Proteins according to the present invention include albumin, globulin,
Gluteli/, prolamin, phosphoprotein.

- secondary induced protein, secondary induced protein JR, etc. Specifically, serum albumin, lactalbumin, ovalbumin, myogen, leucosin (albumin),
Serum globulin, β-lactoglobulin, lysodeme,
Myosin, edestino, insulin, fibrinogen, thyropropurine (globulin), glutenin.

Oryzenin (or glutelin), gliadin.

hordin, zein (prolamin), casein, vitellin, pitellinin, bosvitin C (phosphoprotein), prothian, metaprotein.

Examples include denatured protein (secondary derived protein), secondary glothiose, secondary groteose, peptone, and peptide (secondary derived protein).

The present invention exhibits an excellent de-inking effect due to the strong adsorption of these proteins to ink and the excellent foaming properties, but the amount of the deinking agent for waste paper recycling containing the proteins of the present invention is The amount of protein in the waste paper is 0.005 to 1.5% by weight, preferably 0.05 to 0.5% by weight. Also 1,
If the number is more than 5 times, the dispersibility of the ink in the waste paper disintegration process is too strong, resulting in an insufficient ink removal rate in the flotation process. Therefore, satisfactory results cannot be obtained.

Furthermore, the combination of protein and water-soluble polyvalent metal salt shows even better deinking performance. As a water-soluble polyvalent metal salt,
Examples include galcium chloride, magnesium chloride, aluminum sulfate, and among these, calcium chloride is preferred.

In this case, the blending ratio (weight) of protein and water-soluble polyvalent metal salt
Particularly excellent effects are exhibited in the range of 10/1 to 1/100. If the blending ratio is greater than 1071, sufficient effects of the combined use cannot be obtained in terms of adsorption of proteins to ink and foaming properties with flocheater.

If the blending ratio is less than 1/100, the adsorption of polyvalent metal ions to the ink becomes significant, which acts to neutralize the negative charge of the ink floating in the pulp suspension, making re-adhesion to the pulp more likely. . Therefore, it becomes difficult to obtain pulp with high whiteness. In this case, the steps for adding the water-soluble polyvalent metal salt include a waste paper disintegration step, an aging tower step, and a 70%
Any of the stationary processes may be used. In other words, it exhibits the expected effects in a process prior to flotation.

From the above, the deinking agent of the present invention can provide pulp with high whiteness even when added to either the waste paper disintegration process or the aging tower process.

In implementing the present invention, as long as the effects of the present invention are not impaired,
Surfactants, fatty acids, polymers, oligomers, solvents, acids, alkalis, etc. can be added.

Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.
□'In addition, to evaluate the deinking performance, the whiteness of the recycled valve seat (by colorimeter) and the number of remaining inks (by image analysis device
) was used.

Example 1 After shredding waste newspaper recovered in cloth into 2 x 5 crn pieces, put a certain amount of it into a #M machine on the car, and add water, 1.5% sodium hydroxide (based on raw waste paper), and sodium silicate. No. 3 (used paper as raw material) 4.5%, 3O hydrogen peroxide (used paper as raw material) 1.0
%, deinking agent (for raw waste paper) 0.2% added, pulp density 5
After that, it was disintegrated at 60°C for 20 minutes, and then aged at 45°C for 90 minutes. The drained water was added to dilute the pulp to a concentration of 1.0%, and pulp was prepared using a TAPP entomachine.

Table 1 shows the evaluation results of deinking property.

Table 1 Example 2 After shredding the recovered newspaper in cloth into 2 x 5 cm I/C shreds,
Put a certain amount of it into a tabletop asthmaticizer and add water and hydroxide therein.) I) Rum (based on waste paper as a raw material) 1.096, sodium silicate No. 3 (based on waste paper as a material) 3.0%, and 30% filtrate. After adding 1.0% hydrogen oxide (based on the raw material used paper) and part or all of the deinking agent (Table 2), and decomposing the mixture at a pulp density of 4% at 40°C for 20 minutes,
Add water to bring the pulp density to 1. The mixture was diluted to Oqb, the remainder of the deinking agent was added, and a flotation treatment was performed at 30° C. for 10 minutes. After 70 hours, the pulp slurry was concentrated to a concentration of 6%, water was added to dilute it to a concentration of 1%, and a valve seat was expanded using a Puchuner funnel.

Table 2 shows the evaluation results of deinking properties.

Claims (1)

[Scope of Claims] 1. A deinking agent for recycling waste paper characterized by containing protein. 2. The waste paper according to claim 1, wherein the protein is one or more selected from the group consisting of 7/lz7°min, globulin, glutelin prolamin, protein, secondary induction protein, and secondary induction protein. Deinking agent for recycling. 3. A deinking agent for recycling used paper, characterized by containing protein and a water-soluble polyvalent metal salt. 4. The deinking agent for waste paper recycling according to claim 5, wherein the blending amount of protein and water-soluble polyvalent metal salt is 10/1 to 1/100 in weight ratio. 5. The deinking agent for waste paper recycling according to claim 3 or 4, wherein the water-soluble polyvalent metal salt is a calcium salt.