JPH0157194B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] 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 that can obtain deinked pulp with high whiteness and a small number of residual ink when newspapers, magazines, etc. are deinked by the flotation method. [Conventional techniques and problems] Recycling of newspapers, magazines, etc. has been carried out for a long time, but recently, the effective use of waste paper has become increasingly important due to the shortage of pulp resources and the rising price of pulp. Furthermore, the uses of deinked pulp are expanding to advanced uses. On the other hand, recently used paper is printed using printing technology.
Changes in printing methods, changes in printing ink components, and even the use of waste paper that was previously unrecoverable are making the situation even more difficult in terms of deinking. Improvements have also been made to it. Chemicals traditionally used to separate and remove ink and other impurities from waste paper include alkaline agents such as caustic soda, sodium silicate, soda carbonate, and sodium phosphate, hydrogen peroxide,
Bleach such as hyposulfite and hypochlorite, EDTA,
Along with metal ion sequestering agents such as DTPA, anionic activators such as alkylbenzene sulfonates, higher alcohol sulfate ester salts, α-olefin sulfonates, dialkyl sulfosuccinates, higher alcohols, alkyl phenols, and fatty acids are used as deinking agents. Nonionic surfactants such as ethylene oxide adducts and alkanolamides are used alone or in combination.
It has been used in combination with more than one species. However, although these deinking agents have a high foaming property during flotation treatment, they have a low ink collection ability and only low grade deinked pulp can be obtained. [Means for Solving the Problems] The present inventors have developed a deinking pulp for waste paper recycling that exhibits excellent ink collection ability in flotation treatment and can obtain deinked pulp with high whiteness and low residual ink count. As a result of intensive research to develop an inking agent, the inventors discovered that a deinking agent containing a specific nonionic activator as an essential component satisfies the above performance, and thus arrived at the present invention. That is, the present invention relates to a deinking agent for recycling used paper, which is characterized by containing a reaction product obtained by adding an alkylene oxide to a mixture of natural oils and fats and polyhydric alcohols having a valence of 3 or more. [Function] The fats and oils used in the present invention include vegetable oils such as coconut oil, palm oil, olive oil, soybean oil, rapeseed oil, and linseed oil, animal oils such as pig oil, beef oil, and bone oil, fish oils, and hydrogenated oils thereof; Examples include semi-hardened oils and recovered oils obtained in the refining process of these oils and fats. Examples of the trihydric or higher polyhydric alcohol used in the present invention include glycerin, trimethylolpropane, trimethylolethane, 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,1,1-trimethylol Examples include hexane, pentaerythritol, tetramethylolcyclohexanol, diglycerin, and the like. Examples of the alkylene oxide used in the present invention include ethylene oxide, propylene oxide, butylene oxide, and the like. The addition of alkylene oxides can be carried out by mixing (random addition) or sequential addition (block addition), and random addition or sequential addition of ethylene oxide and alkylene oxides other than ethylene oxide is preferred. The mixing ratio of natural oil and fat and polyhydric alcohol having a valence of 3 or more is 1:0.1 to 1:3 in molar ratio, preferably 1:
The ratio is 0.3 to 1:2. Alkylene oxide is 10 to 100 mol, especially 50 to 90 mol, per 1 mol of the sum of natural oil and fat and polyhydric alcohol.
Preference is given to using moles. If it deviates from this range, the ability to remove ink from waste paper will decrease, and the foaming ability during flotation treatment will also decrease. The addition reaction is not particularly limited, and can be carried out under the conditions of commonly used alkylene oxide addition reactions to compounds having active hydrogen. That is, a catalytic amount of an alkaline substance is added to a mixture of natural oils and fats and polyhydric alcohol prepared at the above molar ratio, and the mixture is heated at about 100 to 200°C for 1 hour.
This can be achieved by reacting alkylene oxide at ~3 Kg/cm ² for several hours. The deinking agent of the present invention is a known deinking agent such as higher alcohol sulfate, alkylbenzene sulfonate,
It also exhibits excellent performance when used in combination with higher alcohols, ethylene oxide adducts of alkylphenols, etc. The deinking agent of the present invention may be added separately to either the waste paper disintegration process, the high-concentration bleaching process, or both processes, but it is most effective when added to the waste paper disintegration process. Also, the amount added is based on the raw material waste paper.
0.2-1.0% by weight is preferred. [Examples and Effects] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. Example 1 After shredding municipally collected newspapers into 2 x 5 cm pieces, put a certain amount of them into a tabletop disintegrator, and add water, caustic soda (based on raw materials) 1.0%, and sodium silicate No. 3 (based on raw materials).
2.5%, 30% hydrogen peroxide (based on raw material) 3.0%, deinking agent shown in Table 1 (based on raw material) 0.4% added, pulp concentration 5
After disintegration at 45°C for 20 minutes, aging treatment was performed at 45°C for 60 minutes. Then add water to adjust the pulp density.
It was diluted to 1.0% and subjected to flotation treatment at 30°C for 10 minutes. The pulp slurry after flotation was concentrated to a concentration of 6%, water was added to dilute it to a concentration of 1%, and a pulp sheet was produced using a tuppy sheet machine. The whiteness of the obtained pulp sheet was measured using a colorimeter and the number of remaining inks was measured using an image analyzer (126x magnification). The results are shown in Table 2.

【table】

【table】

[Table] Example 2 After shredding municipally collected waste newspaper into 2 x 5 cm pieces, put a certain amount of it into a high-concentration pulper, and add water, caustic soda (based on raw materials) at 1.5%, and sodium silicate No. 3 (based on raw materials). Raw materials) 3.0%, 30% hydrogen peroxide (based on raw materials) 3.0%,
Add 0.4% of the deinking agent shown in Table 3 (based on the raw material), and perform decomposition treatment at 45°C for 20 minutes at a pulp concentration of 15%. Thereafter, water was added to the mixture to dilute it to a pulp concentration of 4.0%, and then water was further added to make the pulp concentration 1.0%.
This was subjected to flotation treatment at 30°C for 10 minutes. The pulp slurry after flotation was concentrated to a concentration of 6%, water was added to dilute it to a concentration of 1%, and a pulp sheet was produced using a tuppy sheet machine. The whiteness of the obtained pulp sheet was measured using a colorimeter, and the number of remaining inks was measured using an image analyzer (126x magnification). The results are shown in Table 4.

【table】

【table】

【table】

【table】

Claims (1)

[Scope of Claims] 1. A deinking agent for recycling used paper, characterized by containing a reaction product obtained by adding alkylene oxide to a mixture of natural oils and fats and polyhydric alcohols having a valence of 3 or more. 2. Claim 1, wherein the reaction product is obtained by adding 10 to 100 moles of alkylene oxide to 1 mole of the sum of a mixture of natural oils and fats and trihydric or higher polyhydric alcohols. A deinking agent for recycling used paper. 3. The deinking agent for waste paper recycling according to claim 1, wherein the mixing ratio of the mixture of natural oil and fat and trihydric or higher polyhydric alcohol is 1:0.1 to 1:3 in molar ratio.