JPH0480151B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a deinking agent, and particularly to a deinking agent suitable for deinking waste paper using a floatation method. [Prior Art] Conventionally, due to the shortage of pulp resources and the rising price, it has been widely practiced to recycle and utilize waste paper such as newspapers and magazines. When recycling waste paper,
First, the waste paper is deinked and then paper is made again. The deinking agent first puts waste paper into a pulper filled with an alkaline solution, crushes it into fibers, and then uses the action of the deinking agent to remove colorants, printing ink vehicles, pigments, etc. separated from the fibers. This is done by flotation and separation using a floatator. However, recent waste paper has become extremely difficult to deink due to changes in printing technology, printing methods, diversification of printing ink components, etc., and improvements in deinking processes and deinking agents are required. Moreover, when separating using a floatator in the deinking process, fine carbon particles and pigment particles are extremely difficult to be entrained by air bubbles and tend to remain in the pulp, so it is necessary to generate a large amount of air bubbles. There is. Moreover, in recent years, perpendicular type floatators have come into widespread use in order to reduce the installation area, and a larger amount of foam is required than ever before. Generally, when the amount of foam in a floatator is insufficient, some particles of carbon, pigment, etc. remain in the pulp. As a result, when the waste paper is sent to the washing process in the subsequent process and washed with water, the bubbles break and the once separated particles re-adhere to the pulp, resulting in the so-called ink flow phenomenon. This causes a decline in quality. however,
On the other hand, if a deinking agent with too strong foaming power is used in the floatator, the pulp will also rise to the surface due to the foam, resulting in poor pulp yield. As described above, the selection of the foaming power of the deinking agent is an extremely important factor in the recycling of waste paper. As a deinking agent, use the following formula (), RO(XO)nH...() (In the formula, R is an alkyl group having 8 to 22 carbon atoms, an alkenyl group, or an alkylaryl having an alkyl group having 4 to 12 carbon atoms. Group; (XO)n is C ₂ H ₄ O and C ₃
A mixed polyoxyalkylene group of C ₂ H ₄ O and C ₃ H ₆ O formed by random or block addition polymerization with H 6 O and having a C ₂ H ₄ O content of 15 _to 95% by weight. and n represents an integer from 7 to 150. ) are known. (Japanese Patent Publication No. 51-13762, Japanese Patent Application Laid-open No. 55-51891) [Problems to be solved by the invention] However, with the deinking agent made of the surfactant represented by the above formula (), the ink is removed from the waste paper. Although it has an excellent effect of removing ink and coagulating ink into bubbles, it has a weak foaming power and cannot sufficiently remove ink components with a floatator. As a result, the ink that could not be removed aggregated during the washing process and papermaking process.
There is a problem in that an ink flow phenomenon that remains as a black spot on the sheet occurs, degrading the quality of the product. [Means for Solving the Problems] The present invention has been made to solve the above conventional problems, and is characterized by containing nonionic surfactants represented by the following general formulas () and (). A deinking agent. RO(XO)nH...() (In the formula, R is an alkyl group having 8 to 22 carbon atoms, an alkenyl group, or an alkylaryl group having an alkyl group having 4 to 12 carbon atoms; (XO)n is C ₂ H ₄ O and C ₃
A mixed polyoxyalkylene group of C ₂ H ₄ O and C _{3 H 6 O obtained by random or block addition polymerization with H 6 O and having a C 2 H 4 O content} of 15 to 95% by weight. and n represents an integer from 7 to 150. ) R'O(C ₂ H ₄ O) mH ...() (In the formula, R' is a secondary alkylene group having 8 to 22 carbon atoms; m is an integer of 5 to 30.) It is. That is, as a result of intensive studies to improve the drawbacks of the deinking agent made of the surfactant represented by the above formula (), the present inventors have found that, together with the surfactant represented by the above formula (), a specific surface By using an activator in combination, the degree of bubbles in the floatator increases,
The inventors have discovered that the number of inks remaining on the paper surface of the product is reduced, the average particle size thereof is also reduced, and the whiteness of the product is improved, and the present invention has been achieved. The present invention will be explained in detail below. The deinking agent of the present invention has the above general formulas () and ().
It contains the surfactant shown below. The compound represented by the above general formula () (hereinafter referred to as "surfactant ()") is produced by adding a basic catalyst or an acidic catalyst to a higher alcohol or alkylphenol, and simultaneously introducing ethylene oxide and propylene oxide at high temperature. It can be produced by a known method of adding. Higher alcohols used as raw materials include octyl alcohol, lauryl alcohol,
Examples of the alkylphenol include cetyl alcohol, stearyl alcohol, oleyl alcohol, and synthetic higher alcohols (eg, oxo alcohol), and examples of the alkylphenol include octylphenol, nonylphenol, and dodecylphenol. In addition, the compound represented by the above general formula () (hereinafter referred to as "surfactant ()") is a product obtained by addition polymerization of a secondary alcohol C ₂ H ₄ O group, and the secondary alcohol includes 2,
6,8-trimethyl-4-nonanol, 2-methyl-7-ethyl-4-undecanol, 2-butyloctanol, 6-dodecanol, 3-ethyl-6-undecanol, 3,9-diethyl-6-
Examples include undecanol, 3,9-diethyl 6-tridecanol, and the like, but the present invention is not limited to these, and any known secondary alcohol can be used. The number m of added moles of C ₂ H ₄ O group is not particularly limited,
Any integer from 5 to 30 is selected. The deinking agent of the present invention acts effectively in the process of deinking using the flotation method. In the present invention, the above-mentioned surfactant () and surfactant () may be mixed in advance and added, or each may be added separately at the same time in the same step of the waste paper recycling process, or may be added separately in different steps. The deinking agent may be added to the pulper or tower, although there is no particular restriction as long as it is before the floatator. Also surfactant ()
When adding and () separately, the surfactant () is added to the pulper or tower, and the surfactant () is added to the pulper or tower.
is preferably added at the pulper, tower or floatator inlet. The concentration of the surfactant () is 0.03 to 1% by weight, especially 0.05 to 0.5% by weight, based on the waste paper;
In particular, it is preferably added in an amount of 0.03 to 0.3% by weight. When surfactants () and () are added to the pulper or tower at the same time, their addition ratio (weight) is surfactant (): surfactant () = 20-95:80-5. It is preferable to add it so that [Function] Although the surfactant () is excellent in the effect of removing ink from waste paper and the effect of coagulating ink into foam, it does not have sufficient foaming power. On the other hand, surfactants () have excellent foaming power and are extremely effective in emulsifying and dispersing ink. Therefore, the foaming power of the surfactant (2) increases the amount of foam in the floatator, making it easier to remove ink that has aggregated into foam. In particular, the vertical type floatator, which has been widely used in recent years, requires a large amount of foam for operation, so it is not possible to increase the foam amount by using a surfactant () with this type of floatator. It becomes effective. Moreover, since the surfactant () has excellent ink emulsifying and dispersing properties, it can also prevent excessive agglomeration of ink caused by the surfactant (), thereby reducing the ink flow phenomenon in the subsequent process. It can be prevented. Therefore, by using the surfactants () and () in combination, an extremely good deinking effect can be obtained. In the present invention, it is extremely important that the surfactant () is made by addition polymerizing a C ₂ H ₄ O group to a secondary alcohol, and the excellent deinking effect of the deinking agent of the present invention is due to the surfactant. It cannot be obtained by using the agent () in combination with a primary alcohol prepared by addition polymerization of C ₂ H ₄ O groups. [Examples] The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. Example 1, Comparative Example 1 Deinking treatment was performed using the deinking agent shown in Table 1. Note that the deinking processing method is as follows. Disintegration of waste paper Mainichi, Asahi, and Yomiuri newspapers (all 1 day after printing)
70g of waste paper containing 80% (2 months old) and 20% flyers cut with a turbo cutter and mixed, 10
% sodium hydroxide, 21 g of 10% sodium silicate (No. 3), 0.7 g of hydrogen peroxide, 1% surfactant () in the amount shown in Table 1, and 1280 g of water.
was added, the waste paper concentration was set to 5%, and the waste paper was treated at 55℃ for 20 minutes using a 3-liter Hydrapulper (3000 rpm), and then 933 g of water was added to dilute the waste paper concentration to 3%.
Complete disintegration was achieved by stirring for 5 minutes. Next, 4,666 g of water was added to the completely disintegrated paper stock to further dilute the waste paper concentration to 1%, and the ink was removed using the following method. Ink removal (flotation method) The sample was poured into a 5l photoflotator, and after adding 1% surfactant () in the amount shown in Table 1-1, it was floated for 5 minutes, and the carbon agglomerated in the upper layer. The material was removed and a pulp sheet was obtained by hand-sheeting using a Tatsupi standard sheet machine. The foam height in such deinking treatment, the whiteness of the obtained pulp sheet, and the number of remaining inks were evaluated by the following method. Foam height: Foam height was measured after 1, 2, 3, and 4 minutes using a floatator, and these were averaged and displayed. Whiteness: The reflectance was measured using a photoelectric reflectance meter, assuming that the reflectance of magnesium oxide was 100.
The values in the table are the average values of 5 points x 5 sheets. Number of remaining inks: The number of remaining inks (1
The number of particles in mm ² ) and the average particle size were measured. The results are shown in Table-1.

【table】

〔effect〕

As detailed above, the deinking agent of the present invention is a combination of a conventional surfactant () and a secondary alcohol.
It is used in combination with a surfactant () which is a C ₂ H ₄ O adduct, and deinking can be carried out while maintaining a sufficient amount of bubbles in the floatator. Moreover, the obtained product has no ink running phenomenon, has high whiteness, and is of extremely excellent quality.

Claims (1)

[Scope of Claims] 1. A deinking agent characterized by containing a nonionic surfactant represented by the following general formulas () and (). RO(XO)nH...() (In the formula, R is an alkyl group having 8 to 22 carbon atoms, an alkenyl group, or an alkylaryl group having an alkyl group having 4 to 12 carbon atoms; (XO)n is C ₂ H ₄ O and C ₃
A mixed polyoxyalkylene of C ₂ H 4 O and C _{3 H 6 O, which is formed by random or block addition polymerization with H 6 O and has a C 2 H 4 O content of} 15 _to 95% by weight. group, where n represents an integer of 7 to 150; ) R'O(C ₂ H ₄ O) mH...() (In the formula, R' represents a secondary alkyl group having 8 to 22 carbon atoms; m represents an integer of 5 to 30.)