JPH043475B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a deinking agent used for recycling high-quality waste paper such as newspaper waste paper and magazine waste paper, as well as high-quality waste paper such as imitation waste paper and colored waste paper. [Conventional technology] Recently, due to shortages of raw material pulp for paper manufacturing, rising prices of wood and wood chips, and policies to conserve resources, recycling of waste paper has become more important, but on the other hand, printing inks and printing methods have diversified. Furthermore, with the increase in types of processed paper, it has become more difficult to deink waste paper than before.
Due to the expansion of uses such as replacement of paper, there is a demand for recycled paper with less residual ink, and there is a need for the development of high-performance deinking agents. 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. Representative bleaching agents,
Along with sequestering agents such as EDTA and DTPA,
Nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene block polymer, higher fatty acid alkanolamide, alkylbenzene sulfonate, higher alcohol sulfate, higher alcohol ether sulfate, dialkyl Anionic surfactants such as sulfosuccinates have been used as deinking agents. [Problems to be Solved by the Invention] However, these deinking agents do not have sufficient ability to collect desorbed ink, and only low-quality recycled paper can be obtained. There was a strong desire to develop a powerful deinking agent. Mineral oil, fatty acids, or their salts are known as additives that increase the collection power of detached ink during the flotation process, but mineral oil has insufficient collection power and has little practical effect. Furthermore, there are many problems in working with it, such as a low flash point and a strong odor. Furthermore, although fatty acids have a high ink-capturing ability, they have poor foaming properties during the flotation process, resulting in problems such as insufficient removal of ink and contamination of product pulp. [Means for Solving the Problems] An object of the present invention is to provide a deinking agent that improves the drawbacks of fatty acids while maintaining the strong ink-collecting ability of fatty acids in the flotation process. The deinking agent of the present invention has the general formula [However, _R1 : _C8 to _C20 alkyl group or alkenyl group, p=0 to 20, q=0 to 20, p+q=1 to
30] Nonionic surfactant (a) with general formula R2 _- O-( _CH2CH2O ) _rSO3M [However, _R2 : _{C8 to C20 alkyl} or alkenyl group, or _C8 ~ Alkylphenyl group containing a _C12 alkyl group, r: 1-20, M: alkali metal or ammonium] An anionic surfactant (b) having 8 carbon atoms
~24 higher fatty acids or their salts, (a) + (b) + (c)
(a) = 1 to 45 parts by weight, (b) = 1 to 45 as 100 parts by weight
(c) is contained in a proportion of 50 to 90 parts by weight. [Function] Nonionic surfactant used in the deinking agent of the present invention
(a) is a higher fatty acid alkanolamide or its ethylene oxide (EO) adduct, which increases the foaming properties of the anionic surfactant (b) without interfering with the ink collection properties of the higher fatty acid (c). It has the effect of causing Specifically, coconut fatty acid diethanolamide, coconut fatty acid diethanolamide polyethylene oxide adduct, coconut fatty acid monoethanolamide polyethylene oxide adduct, stearic acid monoethanolamide polyethylene oxide adduct, oleic acid monoethanolamide polyethylene oxide adduct, etc. can be used, but a coconut fatty acid monoethanolamide polyethylene oxide adduct is particularly good in both ink collection power and foaming power, and the number of moles of polyoxyethylene oxide added is preferably 5 to 15 moles. Anionic surfactant used in the deinking agent of the present invention
(b) means that the alkyl group or alkenyl group has 8 carbon atoms.
-20, and if it is outside this range, the foamability in the flotation process will decrease. Also, carbon number 8-12
The same applies to an alkylphenyl group having an alkyl group. Furthermore, if r is out of the range of 1 to 20, the foaming properties will decrease, so r is set to be in the range of 1 to 20. It is important that the higher fatty acid (c) used in the deinking agent of the present invention has 8 to 24 carbon atoms; if the carbon number is less than 8, the ink collection ability will be significantly reduced;
Even if it exceeds 24, the deinking effect will decrease. Specific examples of higher fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and behenic acid. It may also be a mixture of various carbon numbers such as fatty acids, tallow fatty acids, or fish oil fatty acids. In addition, since alkaline chemicals are used in the waste paper disintegration process,
Higher fatty acids act as fatty acid soaps. Therefore, higher fatty acids are salts (sodium,
Potassium, ammonium, etc.) may be used. In the deinking agent of the present invention, 3 of the above (a), (b), and (c)
It is important to make the ingredients essential; no significant effect can be obtained with just any two ingredients. That is, nonionic surfactants (a) and anionic surfactants (b) act as foaming agents, but higher fatty acids (c)
A combination of only a nonionic surfactant (a) and a nonionic surfactant (a) results in less foaming during the flotation process, and a combination of only a higher fatty acid (c) and an anionic surfactant (b) reduces the ink collection ability. decreases. Furthermore, almost no ink collection power can be expected from the nonionic surfactant (a) and anionic surfactant (b) alone. In the deinking agent of the present invention, each of the above components (a), (b) and (c) is 1 to 45 parts by weight (a) + (b) + (c) is 100 parts by weight.
The best deinking performance can be obtained when the ink is mixed in parts by weight, 1 to 45 parts by weight, and 50 to 90 parts by weight. Outside this range, the balance between foaming properties and ink collection properties in the flotation process is not achieved, resulting in unstable operation of the flotation process, making it difficult to obtain recycled paper with high whiteness and little residual ink. . The deinking agent of the present invention may be added in an amount of 0.1 to 0.6% by weight based on the raw waste paper, depending on the type of waste paper, and it can be added to either the pulper or the retention tower to exhibit its effect. Furthermore, the deinking agent of the present invention can also be used in combination with conventionally known deinking agents. [Example] The present invention will be explained below using Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 and Comparative Example 1 (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 treat the waste paper with Deinking agent shown in Table 1 0.3% by weight, caustic soda 1.5% by weight, No. 3 sodium silicate 3.5%
% by weight and 1% by weight of hydrogen peroxide are added to carry out disintegration treatment. This was held at 60°C for 2 hours, then diluted with water at a temperature of 30°C, and 0.6% calcium chloride (based on waste paper weight) was added to make the waste paper concentration 1%. Perform a tissue treatment to remove floss. The treated pulp was hand-sheeted using a Tatsupi standard sheet machine, and its Hunter whiteness, residual carbon content, and average foam height were measured. The results are shown in Table 1. During the evaluation, the average foam height was 10 on the floatator.
The average value for a minute is measured, and Hunter whiteness is determined by Nippon Denshoku Kogyo's colorimetric color difference meter Digital Color Studio.
Measured with CS-101 model, and the remaining carbon within the field of view was measured using a 100x microscope: large: 9 points, medium: 4 points.
Point, small: 1 point and expressed as a score.

【table】

[Table] Example 2 and Comparative Example 2 (High-quality waste paper processing) 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 then process the waste paper. 0.3% by weight of the deinking agent shown in Table 2, 1.5% by weight of caustic soda, and 3.5% by weight of No. 3 sodium silicate.
% by weight and 1.2% by weight of hydrogen peroxide are added to perform disintegration treatment. This was maintained at 50°C for 16 hours, then diluted with water at a temperature of 25°C, and 0.6% calcium chloride (based on waste paper weight) was added to make the waste paper concentration 1%. Perform a tissue treatment to remove floss. The treated pulp was hand-sheeted using a Tatsupi standard sheet machine, and the Hunter brightness and residual carbon content were measured. The results are shown in Table 2.

【table】

〔Effect of the invention〕

As described above, by adding and using the deinking agent of the present invention,
When waste paper is recycled, the ink moderately aggregates, adheres to air bubbles, and collects and floats to the surface during the flotation process, which facilitates the removal of ink and other foreign substances, resulting in high Hunter whiteness. Moreover, recycled paper with less residual ink can be obtained.

Claims (1)

[Claims] 1. General formula [However, _R1 : _C8 to _C20 alkyl group or alkenyl group, p=0 to 20, q=0 to 20, p+q=1 to
30] A nonionic _surfactant (a) represented by the general formula _R2 -O-( _CH2CH2O ) _rSO3M [however,
_R2 : _C8 - _C20 alkyl or alkenyl group, or alkyl phenyl group containing a _C8 - _C12 alkyl group, r: 1-20, M: alkali metal or ammonium] Anionic surfactant represented by agent (b), and a higher fatty acid having 8 to 24 carbon atoms or a salt thereof (c),
(a) = 1 to 45 parts by weight, where (a) + (b) + (c) is 100 parts by weight,
A deinking agent for recycling waste paper, characterized in that the deinking agent is contained in a ratio of (b) = 1 to 45 parts by weight and (c) = 50 to 90 parts by weight. 2. The deinking agent for waste paper recycling according to claim 1, wherein the nonionic surfactant (a) is a higher fatty acid monoethanolamide polyoxyethylene oxide adduct.