JPS6411756B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a deinking agent used for recycling high-quality waste paper such as waste newspapers and magazines, imitation waste paper, and colored waste paper. Waste paper is generally recycled using alkali metal hydroxides such as caustic soda, soda carbonate, and No. 3 sodium silicate, inorganic chemicals such as carbonates and silicates, hydrogen peroxide, and hypochlorites. bleaching agents, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polyoxypropylene block polymers, nonionic surfactants such as higher fatty acid alkanolamides, alkylbenzene sulfonates, higher alcohol sulfates, higher alcohol ethers. Anionic activators such as sulfates and dialkyl sulfosuccinates, other higher fatty acids and their salts, mineral oil, etc. are added during the disintegration process of waste paper, and in some cases during the soaking process, and these chemicals have chemical and mechanical effects. This is accomplished by (1) separating printing ink and other foreign matter from the waste paper, (2) emulsifying and dispersing the separated ink and other foreign matter, and (3) causing the dispersed particles to adhere to air bubbles and float. Recently, the recycling of waste paper has become more important due to the shortage of raw material pipes for paper manufacturing, the soaring prices of main materials and chips, and policies to conserve resources.
Due to the diversification of printing methods and the increase in types of processed paper, it has become more difficult to remove ink from waste paper than before, and the use of recycled paper is expanding, such as replacing newspaper, magazine printing paper, or BKP. Therefore, recycled paper with less residual ink is required, and the development of surfactants with good ink removal performance is desired. An object of the present invention is to provide a deinking agent that can produce finished pulp with higher Hunter whiteness and less residual ink than conventional deinking agents for various types of waste paper. The deinking agent of the present invention has the general formula (1) R ₁ COO(-AO)- _l1
H and general formula (2) R ₁ COO (−A′O) − _l2 COR ₂ [However,
R ₁ and R ₂ are alkyl or alkenyl groups having 7 to 21 carbon atoms, and may be the same or different, (-AO
) _-l1 and (-A′O) _-l2 are alkylene groups having 2 to 4 carbon atoms, and if two or more types of alkylene groups are present in the chain, it may be a block polymer or a random polymer, and the total The molecular weight is 2,000 to 20,000] and contains one or both of the compounds as essential components. The deinking agent of the present invention can be obtained, for example, by reacting a polymer to which an alkylene oxide has been added with a fatty acid to perform an esterification reaction, or by adding an alkylene oxide to a fatty acid. Specific fatty acids include capric acid, lauric acid, myristic acid, palmitic acid,
Stearic acid, oleic acid, linoleic acid, behenic acid, etc., and coconut oil fatty acids containing these fatty acids, soybean fatty acids, tall oil fatty acids, beef tallow fatty acids,
Fish oil fatty acids, etc., or fatty acids obtained from natural products of hydrogenated products of these fatty acids, synthetic fatty acids, etc. can be used. Considering the foaming properties and ink collection properties of the deinking agent of the present invention during flotation, the alkylene oxide is preferably ethylene oxide alone, ethylene oxide and propylene oxide, or a combination of ethylene oxide and butylene oxide. Similarly, R in the formula is preferably an alkyl group or alkenyl group having 11 to 17 carbon atoms, and if the overall molecular weight is less than 2,000, the ink collection property is weak, and if it exceeds 20,000, the solubility is poor. Because of the problem, it needs to be between 2000 and 20000, and especially preferably between 4000 and 16000. Regarding the use of the deinking agent of the present invention, it may be used alone, or other deinking agents may be used, such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene block polymer, high grade nonionic activators such as fatty acid alkanolamides,
It may be used in combination with anionic activators such as alkylbenzene sulfonates, higher alcohol sulfates, higher alcohol ether sulfates, and dialkyl sulfosuccinates.In general, deinking agents are often used in combination depending on the target waste paper. The inking agent is generally added in an amount of 0.05 to 0.5% by weight to the raw waste paper, depending on the type of waste paper, but when the deinking agent of the present invention is used alone, this range is sufficient; When used in combination with a deinking agent, it is effective if 1% by weight or more of the deinking agent is the deinking agent of the present invention. In addition, regarding the locations where the deinking agent of the present invention is added, (1) pulper, (2) retention tower, and (3) floatator, (1), (1) and (2), (1) and ( It is best to add it to 3). As described above, by adding and using the deinking agent of the present invention,
When waste paper is recycled, the ink components moderately aggregate, adhere to air bubbles, and are collected and floated to the surface during the flotation process using a floatator, which facilitates the removal of ink and other foreign substances, resulting in improved Hunter whiteness. It is possible to obtain a finished pulp with high ink and low residual ink. Examples will be described below, but the present invention is not limited thereto. Example (refined waste paper processing) After cutting 50 g of newspaper and magazine waste paper into approximately 2 cm squares, put it in a mixer, add water at 30°C to make the waste paper concentration 5%, and apply 0.2 weight of deinking agent to this waste paper. %, 1.5% by weight of caustic soda, 3.5% by weight of No. 3 sodium silicate, and 1% by weight of hydrogen peroxide for disintegration treatment. This was maintained at 60°C for 2 hours, and then diluted with water to a temperature of 30°C and a waste paper concentration of 1%, and subjected to flotation treatment for 5 minutes using a floatator (manufactured by Kyokuto Shinko) to remove the floss. The treated pulp was hand-sheeted using a Tatsupi standard sheet machine, and the Hunter brightness and residual carbon content were measured. During the evaluation, Hunter whiteness was measured using a colorimeter Digital Color Studio CS-101 manufactured by Nippon Denshoku Kogyo, and residual ink was measured using a 100x microscope in the field of view, large: 9 points, medium: 4 points. Point, small: 1 point and expressed as a score. Example (Processing of high-quality waste paper) After cutting 50 g of imitation and colored waste paper into approximately 2 cm squares, put it in a mixer, add water at 30°C to make the waste paper concentration 5%, and add 0.2 weight of deinking agent to this waste paper. %, caustic soda 1.5% by weight, No. 3 sodium silicate 3.5% by weight, and hydrogen peroxide 1.2% by weight to perform disintegration treatment. This was maintained at 50° C. for 16 hours, and then diluted with water to a temperature of 25° C. and a waste paper concentration of 1%, followed by flotation treatment for 5 minutes in a floatator (manufactured by Kyokuto Shinko Co., Ltd.) to remove the floss. The treated pulp was hand-sheeted using a Tatsupi standard sheet machine, and the Hunter whiteness and amount of remaining ink were measured. During the evaluation, Hunter whiteness was measured using a colorimetric colorimeter Digital Color Studio CS-101 manufactured by Nippon Denshoku Kogyo. : 4 points, small: 1
It was expressed as a score. The following deinking agent was used in Examples and in the following examples: Deinking agent A Deinking agent B Deinking agent C Deinking agent D Deinking agent E R ₂ COO (−CH ₂ CH ₂ O) − ₄₀ COR ₂ Deinking agent F Deinking agent G Deinking agent H R ₂ COO (-CH ₂ CH ₂ O) - ₃₀ COR ₂ Deinking agent I Deinking agent J Deinking agent K Higher alcohol ethoxylate (9 mol adduct of EO) Deinking agent L Higher alcohol ether sulfate (3 mol adduct of EO) However, R ₁ CO in the formula of deinking agents A to J is a lauric acid residue, R ₂ CO represents an oleic acid residue, R ₃ CO represents a fish oil fatty acid residue, R ₄ CO represents a caproic acid residue, and R ₅ CO represents a lignoceric acid residue. The results are shown in Table 1 and Table 2 for each example of the present invention and a comparative example.

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[Table] Table-1 Refined Waste Paper Processing (Example) and Table-
From the results of high-quality waste paper treatment (Example) in 2, it is clear that the product of the present invention increases Hunter whiteness and reduces residual ink compared to general deinking agents such as nonionic activators and anionic activators. It can be seen that it has excellent deinking performance that reduces the number of inks.

Claims (1)

[Claims] 1 General formula (1) R ₁ COO−(AO−) l ₁ H and General formula (2) R ₁ COO(−A′O) − _l2 COR ₂ [However, R ₁ , R ₂ are an alkyl group or an alkenyl group having 7 to 21 carbon atoms, and may be the same or different, and (-AO) _-l1 and (-A′O) _-l2 are
~
In a polyoxyalkylene chain formed by polymerizing the oxyalkylene of 4, if two or more types of oxyalkylene groups are present in the chain, even if it is a block polymer chain,
Random polymer chains may be used, and the overall molecular weight is 2000
A deinking agent for waste paper recycling, characterized by containing one or both of the compounds shown in the following formula.