JPS6350590A - Deinking agent for regenerating old paper - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a deinking agent for recycling used paper used when recycling pulp from used printed paper such as newspapers and magazines.

[Conventional technology]

It is well known that fatty acids or fats and oils are used as one of the active ingredients of deinking agents for waste paper recycling, and that these mainly act as flocculants for the ink after it has been removed from the waste paper (Japanese Patent Application Laid-Open No. Publication No. 50-25805, Japanese Patent Application Laid-Open No. 142804-1980, Japanese Patent Application Publication No. 15579-1987
Publication No. 4, etc.).

These fatty acids or fats and oils are used in the disintegration step of deinking processing, that is, while disintegrating printed waste paper in a pulper, alkali and deinking agent are applied to it in the presence of a bleaching agent as necessary to form ink. When added to the above-mentioned disintegration step in a method of desorbing ink from waste paper and then flotating the desorbed ink to separate it from the pulp slurry,

[Problem that the invention seeks to solve]

However, when fatty acids or fats and oils that are solid at room temperature are used, the energy cost for melting them is extremely high.Furthermore, even when using fatty acids or fats that are liquid at room temperature or melted, they can be directly used in the disintegration process. When added to water, the dispersibility in water is poor and a sufficient ink aggregation effect cannot be obtained.

[Means for solving problems]

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention found that by using a fatty acid or oil as an emulsion in which the fatty acid or oil is emulsified in water in advance, even when using a fatty acid or oil that is solid at room temperature, the The present invention was achieved based on the discovery that it can be handled as a liquid, and that even when added to an aqueous system such as in a disintegration process, it is easily dispersed and an effective flocculating effect can be obtained.

That is, the present invention relates to a deinking agent for recycling used paper, which contains as an active ingredient an emulsion of fatty acids or an emulsion of a mixture of fats and oils and fatty acids.

[Structure and operation of the invention]

The fatty acid constituting the fatty acid or fat used in the present invention usually has 4 to 30 carbon atoms, preferably 1O to 22 carbon atoms.
It is. Examples of particularly suitable fatty acids include valmitic acid, stearic acid, oleic acid, tallow fatty acid, hydrogenated tallow fatty acid, coconut oil fatty acid, palm oil fatty acid, soybean oil fatty acid,
These include palm kernel oil fatty acids. Particularly suitable fats and oils include beef tallow, soybean oil, coconut oil, palm oil, and palm kernel oil.

In the present invention, the above-mentioned fatty acids are used either as an emulsion alone or as an emulsion of a mixture with oil or fat, but the proportion of fatty acids in the above-mentioned mixture is 30% by weight or more, preferably 50% by weight or more. It is better to do so.

When the ratio of fatty acids is less than 30% by weight, adsorption to the desorbed ink is poor (and no effective coagulation effect can be obtained).

The emulsifier used to obtain the emulsion of the present invention is not particularly limited, as long as it does not adversely affect the aggregation effect of the detached ink or the foaming effect of the foaming agent used at the same time. Anything is fine.

That is, examples of the emulsifier include commonly used anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. Specific examples include, for example, Part ``Surfactant Handbook''
(Sangyo Tosho Co., Ltd.) and "Elucidation of the Functional Effects of New Surfactants and the Development and Practical Comprehensive Technical Data Collection of Applied Products" edited by Soft Giken Publishing Department (Management Development Center Publishing Department), etc. can be mentioned. Furthermore, part of the fatty acid or the mixture of fat and oil and fatty acid used may be converted into salt to serve as an emulsifier.

The composition of the emulsion obtained using such an emulsifier differs depending on the type of fatty acid used or the mixture of the fatty acid and fat or oil. However, in general, it is preferable that the concentration of the fatty acid or the mixture thereof with fat or oil be 5 to 50% by weight in water, and the concentration of the emulsifier be 2 to 30% by weight.

The present invention is characterized in that such an emulsion is used as one of the active ingredients of a deinking agent for waste paper recycling, but as is clear from what has been described above, this emulsion causes the aggregation of desorbed ink. It mainly acts as an agent, and therefore, appropriate foaming is usually used to effectively remove the ink from the waste paper and to effectively separate the agglomerated ink from the system in the next flotation step. agents are used simultaneously. That is, the purpose of removing ink can be effectively achieved by using a combination of the emulsified flocculant and the foaming agent as a deinking agent.

As the above-mentioned foaming agent, a wide range of conventionally known foaming agents can be used, such as nonionic foaming agents such as ethylene oxide adducts or ethylene oxide propylene oxide adducts to higher alcohols, fatty acids, higher alkyl amines, fatty acid amides, polypropylene glycols, alkylphenols, etc. surfactants, sulfonated products of these nonionic surfactants, and anionic surfactants such as alkylbenzene sulfonic acids.

The deinking agent of the present invention is added to the disintegration step in the deinking treatment as is commonly done, and this addition can be carried out by directly adding it as a liquid at room temperature to the aqueous system such as the above-mentioned step. The amount added at this time is usually 0.05 to 2% by weight of the fatty acid or the mixture of this and fat and oil in the emulsion that serves as the coagulant component, based on the recycled waste paper.
In the above-mentioned foaming agent component, it is preferable that the same proportion as above is usually 0.05 to 2% by weight.

In addition, in the disintegration step, as is well known, alkaline aids such as sodium hydroxide and sodium silicate, and bleaching agents such as hydrogen peroxide can be added at the same time.

〔Effect of the invention〕

As described above, if the deinking agent for waste paper recycling containing the emulsion of fatty acids or the emulsion of a mixture of fats and oils and fatty acids of the present invention as an active ingredient is used, it is liquid at room temperature and can be added as is without heating. Furthermore, since an excellent agglomeration effect of the ink released during the disintegration process can be obtained, a bulb with excellent whiteness can be regenerated.

〔Example〕

EXAMPLES Below, the present invention will be explained in more detail by describing examples.

Examples 1 to 9 As a foaming agent component, coconut alcohol PO (5 mol) E
Using a 1:1 mixture of a sulfonated product of O (7 mol) adduct and an EO (10 mol) adduct of nonylphenol, this and the flocculant components shown in Table 1 below were mixed according to the weight ratio of both components (solid The deinking agent for waste paper recycling of the present invention was prepared by combining the two in a ratio that gave a ratio of 3. In addition, the above EO means ethylene oxide and PO means propylene oxide, respectively.

Table 1 Note that each emulsion shown in Table 1 above uses a nonionic surfactant as an emulsifier in Examples 1 to 5, and a nonionic surfactant and an anionic surfactant in Examples 6 to 9. The concentration of each fatty acid or its mixture with fats and oils in water was 20% by weight.

Comparative Examples 1 to 6 Except for changing the flocculant components to those shown in Table 2 below,
Comparative deinking agents for waste paper recycling were obtained in the same manner as in Examples 1 to 9.

Table 2 Using each of the deinking agents according to the above Examples and Comparative Examples, a deinking treatment test was conducted in the following manner.

Disintegration of waste paper〉 Mainichi, Asahi, Yomiuri newspapers (both 1 to 2 months old) and 20 weight% of leaflets were cut into 70g of used paper and mixed with a turbo cutter.
10.5 g of wt.% sodium hydroxide, 21 g of 10 wt.% sodium silicate (No. 3), 0.7 g of hydrogen peroxide, 14 g of deinking agent diluted with water to a concentration of 2 wt.% and 1.2 g of water.
Add 80g and reduce the waste paper concentration to 5% by weight to make the capacity 3I! After processing for 20 minutes at 55° C. using Hydra pulper (3,00 Or pm), 933 g of water was added to dilute the waste paper concentration to 3% by weight, and the paper was stirred for 5 minutes to completely disintegrate.

Flotation method> After the above complete disintegration, 4,666 g of water was added to dilute the waste paper concentration to 1% by weight, and this was poured into a 51 fluorite flotator and floated for 10 minutes to remove the upper layer. Carbon aggregates were removed and a valve seat was obtained by hand-sheeting using a Tarapee standard sheet machine.

<Deinking effect evaluation method> The whiteness and the number of remaining inks of the valve sheets obtained by the above method were examined by the following method to evaluate the deinking effect. The results were as shown in Table 3 below.

9 Whiteness: Photoelectric reflectance meter (SM manufactured by Suga Test Instruments Co., Ltd.
Blue reflectance was measured using a color computer Model 5M-4). Note that the values in Table 3 are the average values of 5 points x 5 sheets.

5 Number of remaining inks 2 The number of remaining inks was counted using an image analyzer (x l O0 times) and converted into a value per cnt.

Table 3 From the results shown in Table 3 above, excellent deinking effects can be obtained when the deinking agent containing the fatty acid emulsion of the present invention or the emulsion of a mixture of fat and oil and fatty acid as an active ingredient is used. However, it can be seen that the deinking effect is inferior when the deinking agent of the comparative example is used.

Claims (3)

[Claims] (1) A deinking agent for recycling used paper, which contains as an active ingredient an emulsion of fatty acids or an emulsion of a mixture of fats and oils and fatty acids. (2) The number of carbon atoms in fatty acids or fatty acids constituting fats and oils is 4
30. The deinking agent for waste paper recycling according to claim (1). (3) The deinking agent for waste paper recycling according to claim (1) or (2), wherein the content of fatty acid in the mixture of fat and oil is 30% by weight or more.