JPH0423036B2 - - 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, when deinking newspapers, magazines, etc. by the flotation method, in order to obtain deinked pulp with high whiteness and a small number of residual inks derived from offset ink, especially deinked pulp with a small number of unpeeled inks. This invention relates to a deinking agent for recycling used paper. [Prior art and problems] Recycling of newspapers, magazines, etc. has been carried out for a long time, but recently it has become especially important, and the use of deinked pulp is also becoming more advanced. Demand is increasing. On the other hand, in recent years, the situation with waste paper has become even more difficult from the perspective of deinking due to changes in printing technology, printing methods, changes in printing ink components, weight reduction, etc., and improvements have also been made to equipment to further promote deinking. are being added. Chemicals traditionally used to separate and remove ink and other impurities from waste paper include alkaline agents such as caustic soda, sodium silicate, and sodium phosphate, and bleaching agents such as hydrogen peroxide, hyposulfite, and hypochlorite. There are metal ion sequestering agents such as DTPA and EDTA, and along with these agents, anionic active agents such as alkylbenzene sulfonates, higher alcohol sulfate ester salts, α-olefin sulfonates, and dialkyl sulfosuccinates are used as deinking agents. agent,
Nonionic surfactants such as higher alcohols, EO adducts of alkylphenols, EO/PO adducts, and alkanolamides have been used singly or in combination of two or more. However, these deinking agents have a low ability to separate and remove ink during flotation treatment, and therefore there has been a demand for the development of a deinking agent that has excellent ink coagulation ability. In addition, it is difficult to completely separate ink from waste paper, and as the use of deinked pulp has expanded and the blending ratio has increased recently, the presence of ink that has not separated from waste paper, that is, unreleased ink, has become a problem. There is a growing demand for the development of deinking agents with even better ink release properties. [Means for Solving the Problems] Therefore, the present inventors have developed a paper that has excellent ink removal power from waste paper, and furthermore, in the flotation process, the released ink is adsorbed to air bubbles and separated and removed from the pulp fibers, resulting in high whiteness and As a result of intensive research to develop a deinking agent that can obtain deinked pulp with a low number of residual inks, especially a deinked pulp with a low number of unreleased inks,
The invention has been completed. That is, the present invention provides (a) a compound represented by general formula (1) R ₁ COO−(AO)− _o R ₂ ...(1) (in formula (1), R ₁ is an OH group as a substituent) _R2 represents H or an alkyl group, alkenyl group or acyl having 1 to 22 carbon atoms, and AO
represents an oxyalkylene group having 2 to 4 carbon atoms,
n is a number such that the overall molecular weight is 2000 or less. ) and (b) Deinking for used paper recycling, which is made by mixing the reaction products of natural oils and fats, polyhydric alcohols, and alkylene oxides in a weight ratio of (a)/(b) = 70/30 to 5/95. It is intended to provide an agent for The compound represented by the general formula (1) according to the present invention is critical, and even if it is a similar compound, it cannot obtain the remarkable effects of the present invention. I can't do it. Therefore, the limitations and numerical values of the functional groups represented by general formula (1) are extremely important. For example, instead of R ₁ COO- group, R ₁ O- group (R ₁ is a general formula
The same conditions as in (1)) are inferior in ink collection and ink release properties during flotation. Examples of the alkylene oxide constituting the oxyalkylene group include ethylene oxide, propylene oxide, butylene oxide, etc., and two or more types of alkylene oxides may be added. The addition of two or more alkylene oxides can be carried out by random addition or block addition, but random addition or block addition of ethylene oxide and alkylene oxides other than ethylene oxide is preferred. _R2 is H or an alkyl group, alkenyl group, or acyl group having 1 to 22 carbon atoms, and preferably H, a methyl group, or an acyl group having 8 to 22 carbon atoms. Furthermore, it is important that the total molecular weight is 2000 or less; if it exceeds 2000, the ink collection and foaming properties during flotation will be poor, making it impossible to obtain high-quality recycled pulp. Next, (b) reaction products will be explained. Natural oils and fats 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 lard, beef tallow, and bone oil, fish oils, and hydrogenated and semi-hardened oils thereof. Further examples include recovered oils obtained in the refining process of these oils and fats. Polyhydric alcohols include ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, glycerin, trimethylolpropane, trimethylolethane,
Examples include 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,1,1-trimethylolhexanol, pentaerythritol, tetramethylolcyclohexanol, diglycerin, and the like. Examples of the alkylene oxide 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), but random addition or block addition of ethylene oxide and alkylene oxides other than ethylene oxide is preferred. . The mixing ratio of natural oil and fat and polyhydric alcohol is 1:0.1 to 1:3 in molar ratio, preferably 1:0.3 to 1:2.
It is. Alkylene oxide is 5 mol or more, especially 20 to 100, per 1 mol of the sum of natural oil and fat and polyhydric alcohol.
Preference is given to using moles. If the amount is less than 5 moles, the ink release property from waste paper and the foaming property during flotation treatment will be reduced. The reaction between natural fats, polyhydric alcohols, and alkylene oxides is usually carried out by blowing alkylene oxide into a mixture of natural fats, polyhydric alcohols, and natural oils mixed in the above proportions, and reacting with the addition reaction of the alkylene oxides between the natural fats and polyhydric alcohols. However, even if you change the order and first react the alkylene oxide with the polyhydric alcohol, and then react it with the natural oil, you will not be able to obtain a product that has the same deinking performance. is obtained. The addition reaction is not particularly limited, and can be carried out under the conditions of a commonly used alkylene oxide addition reaction to a compound having active hydrogen. For example, a catalytic amount of an alkaline substance is added to a mixture of natural oils and fats and polyhydric alcohol prepared in the above molar ratio, and the mixture is heated at about 100 to 200°C and 1 to 3 kg/cm ^{2 .}
This can be achieved by reacting an alkylene oxide for several hours. In the deinking agent of the present invention, the blending ratio of components (a) and (b) is in a weight ratio of (a)/(b) = 70/30 to 5/95, preferably 60 to 40. ~30/70. If it is outside this range, the balance between ink cohesiveness and foamability during flotation will be disrupted, making it impossible to obtain pulp with high whiteness and a low number of remaining inks. That is,
If (a)/(b) is greater than 70/30, flotation results in high foaming, pulp outflow is large, and ink cohesion is poor. Furthermore, when (a)/(b) is smaller than 5/95, the flotation results in low foaming, making it impossible to efficiently remove aggregated ink from the system, making it impossible to obtain high-quality deinked pulp.
As a result, outside the above range, a large amount of unpeeled ink is present and only low-quality deinked pulp can be obtained. The deinking agent of the present invention may be added separately to either the waste paper disintegration process, the aging tower process, or both processes, but it is most effective when added to the waste paper disintegration process. The amount added is preferably 0.2 to 1.0% by weight based on the raw waste paper. Further, the deinking agent of the present invention can also be used in combination with known deinking agents that have been commonly used. [Examples and Effects of the Invention] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. Example 1 First, component (b) of the present invention (samples 1 to 7) was prepared with the composition shown in Table 1. Next, after shredding the recycled newspapers into 2 x 5 cm pieces, put a certain amount of them into a tabletop disintegrator, and add water and caustic soda (to the raw material).
1.0% (by weight, same below), sodium silicate (based on raw materials) 3.0%, 30% hydrogen peroxide solution (based on raw materials) 3.0%,
Add 0.4% of various deinking agents (based on raw materials) shown in Table 2, and dissolve at 55℃ for 20 minutes at a pulp concentration of 5%.
Aged for 60 minutes at ℃. Thereafter, water was added to dilute the pulp to 1.0%, 1.0% CaCl ₂ (based on raw materials) was added, and a flotation treatment was performed at 30° C. for 10 minutes. After the pulp slurry after flotation was concentrated to a concentration of 6%, water was added to dilute it to a concentration of 1%.
A pulp sheet was produced using a TAPPI sheet machine. The whiteness of the obtained pulp sheet was measured using a colorimeter, and the number of remaining inks and the number of unpeeled inks was measured using an image analyzer (×126 magnification). The results are also shown in Table-2.

【table】

[Table] Oxide.

[Table] 〓 〓 means random addition.
Example 2 After shredding municipally collected newspaper waste into 2 x 5 cm pieces, put a certain amount of it into a tabletop disintegrator, and add water, caustic soda (based on raw materials) 1.0%, and sodium silicate No. 3 (based on raw materials).
0.5%, various deinking agents shown in Table 3 (based on raw materials) 0.4
%, pulp concentration 5%, 45℃, 20 separations,
Dehydrate the pulp to a concentration of 18%, and add 1.5% caustic soda (based on the raw material), 2.5% sodium silicate No. 3 (based on the raw material), and 3.0% hydrogen peroxide solution (based on the raw material).
After adding and mixing, 55℃, 90 minutes, pulp density
Aging treatment was performed at 15%. Then pulp concentration 4%
Add water and disintegrate for 5 minutes using a tabletop disintegrator, add water to dilute the pulp to 1.0%, add 1.0% CaCl ₂ (based on raw materials), and store at 30℃.
Flotation treatment was performed for 10 minutes. After concentrating the pulp slurry after flotation to a concentration of 6%,
The mixture was diluted with water to a concentration of 1%, and a pulp sheet was produced using a TAPPI sheet machine. The whiteness of the obtained pulp sheet was measured using a colorimeter, and the number of remaining inks and the number of unpeeled inks was measured using an image analyzer (×126 magnification). The results are also shown in Table 3.

【table】

Claims (1)

[Claims] 1 (a) Compound represented by general formula (1) R ₁ COO−(AO)− _o R ₂ ...(1) (In formula (1), R ₁ is OH as a substituent) an alkyl group or alkenyl group having 7 to 21 carbon atoms which may have a group, _R2 represents H or an alkyl group having 1 to 22 carbon atoms, alkenyl group or acyl, AO
represents an oxyalkylene group having 2 to 4 carbon atoms,
n is a number such that the overall molecular weight is 2000 or less. ) and (b) Deinking for used paper recycling, which is made by mixing the reaction products of natural oils and fats, polyhydric alcohols, and alkylene oxides in a weight ratio of (a)/(b) = 70/30 to 5/95. agent. 2. The deinking agent for waste paper recycling according to claim 1, wherein the reaction product is obtained by adding 5 moles or more of alkylene oxide to 1 mole of the sum of natural oil and fat and polyhydric alcohol. 3 The mixing ratio of natural oil and fat and polyhydric alcohol is
The deinking agent for waste paper recycling according to claim 1, which has a molar ratio of 1:0.1 to 1:3.