JPH0551888A - Treatment of waste paper - Google Patents

Abstract

PURPOSE:To accomplish the title treatment by adding a specific pigment to a mixture of non-carbon waste paper and toner-print waste paper in deinking said mixture to obtain high-quality deinked pulp even in the presence of the encapsulated oil coated on the non-carbon waste paper. CONSTITUTION:The objective deinking treatment can be accomplished by adding an inorganic and/or organic pigment (e.g. white carbon, talc) >=45ml/100g in oil absorption to a mixture comprising at least non-carbon waste paper and toner-print waste paper among a various kinds of information-recorded waste paper. The amount of the pigment to be added is pref. 10-20wt.% based on the non-carbon waste paper in unscreened waste paper. Pigment addition may be made at either point; namely: (A) in disaggregating the waste paper, or (B) in its kneading for the purpose of removing toner ink along with disaggregation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes waste unrecorded information recording paper to obtain good deinked pulp (hereinafter referred to as DIP) by subjecting waste information recording paper generated from an office to uninking treatment. It is related to the ink method.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of resource / environmental protection and measures against municipal waste, there is a growing tendency to promote the use of waste paper. A particular problem here is the waste information recording paper discarded from offices and the like. This kind of waste paper is composed of toner prints from electrophotographic copying machines and laser printers, carbonless copy papers, thermal papers, back carbon copy papers, and the like. Of these information recording paper waste papers, carbonless paper, thermal paper, back carbon paper, etc. are so-called contraindicated products, because the DIP obtained when mixed with general waste paper causes coloring and colored spots appear. Has been done. Toner-printed waste paper is extremely inadequate to be deinked by a general deinking method consisting of disaggregation, floating sorting and washing. Thus, it can be said that all the information recording paper waste paper is difficult to deink ink waste paper. For some of the above-mentioned used information recording paper, a single processing method is known.

Regarding a method for independently treating waste carbonless carbon paper, Japanese Patent Publication No. Sho 64-3991, Japanese Patent Laid-Open No. Sho 60-231.
889, JP-A-55-98990, JP-A-55-658
No. 0, JP-A-54-138605 and the like. Further, it is well known that waste toner-printed paper can be efficiently separated and removed by adding disintegrated waste paper to a treatment step using a kneader or a disperser.

[0004]

As described above, a method of independently treating a specific used information recording paper is known to some extent. However, it takes a lot of labor and time to sort such used information recording paper that contains toner printed waste paper, carbonless waste paper, thermal paper waste, back carbon waste waste paper, etc. generated from the office. It's extremely difficult. The present invention provides a technique for obtaining good DIP from so-called unsorted waste information recording paper, which does not sort waste information recording paper generated from offices. Unsorted information recording waste paper, that is, carbon-free waste paper and toner printed waste paper In mixed waste paper, mechanical shearing force due to high-concentration kneading and ink separation and removal are inadequate even if washing is strengthened. It has been found that the stronger the ink is, the larger the amount of the coarse ink is, and the good DIP cannot be obtained.
As a result of various studies on this problem, it was found that the oil in the microcapsules coated on the carbonless paper was the cause. It is considered that the main reason for this is that the toner particles became sticky due to the oil in the capsules and aggregated to become coarse.

[0005]

As a result of the diligent efforts of the present inventors, when deinking used information recording paper waste paper generated from the office in an unsorted state in which waste carbonless paper and waste toner printed material are mixed, Inorganic and / or organic pigments with an oil absorption of 45 ml / 100 g or more, such as white carbon, talc, clay, precipitating calcium carbonate, urea resin, etc. are added, and deinking treatment is applied to carbonless waste paper. It was found that the desired good DIP can be obtained even in the presence of the prepared capsule oil.

Concretely, caustic soda, sodium silicate, hydrogen peroxide, a surfactant, etc. are added to the used waste paper as needed to disintegrate, and then deinking treatment such as aging, kneading, flotation, etc. To do. The pigment added at that time is
It is not particularly limited, either during disintegration of used paper or during needing for exfoliating and miniaturizing the toner ink. Further, the addition amount is 5% by weight to 25% by weight, preferably 10% by weight to 20% by weight, with respect to the non-carbon waste paper mixed in the unsorted waste paper. When the amount is 5% by weight or less, the sufficient effect cannot be obtained, and even when 25% by weight or more is added, the effect is almost leveled off, which is not economically advantageous. Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0007]

【Example】

Comparative Example 1 To 500 g of completely dried waste paper blended as shown in Table 1, 1.0% by weight of caustic soda and 2.0 silicate of sodium were used.
% By weight, 0.5% by weight of hydrogen peroxide, 0.3% by weight of a fatty acid derivative-type surfactant, and disintegrated with a pulper having a volume of 5 liters to give a pulp concentration of 15% by weight at 55 ° C. for 2 hours. After dehydration to 25% by weight and performing a kneading treatment with a biaxial kneader for experiments, the ink was removed with a floater (manufactured by Kyokuto Shinko Co., Ltd.) having a volume of 5 liters. After adjusting the pH of the obtained pulp slurry to pH 6.5 with a sulfuric acid band, JIS method hand-papermaking was performed, and residual ink was measured by an image analyzer manufactured by Nexus Co., Ltd. The results are as shown in Table 3.

Comparative Example 2 The same process as in Comparative Example 1 was carried out except that talc having an oil absorption of 35 ml / 100 g was added in an amount of 17% by weight with respect to the waste carbon paper when disintegrating the waste paper. The results are shown in Table 3.

Comparative Example 3 The same process as in Comparative Example 1 was carried out except that 17% by weight of clay having an oil absorption of 40 ml / 100 g was added to the waste carbon paper when disintegrating the waste paper. The results are shown in Table 3.

Comparative Example 4 As shown in Table 2, the same processing as in Comparative Example 1 was carried out with the used ratio of waste toner printed waste paper and carbonless waste paper being 1: 1. The results are shown in Table 3.

Example 1 Talc having an oil absorption of 45 ml / 100 g was added in an amount of 17% by weight to carbonless waste paper, and the same treatment as in Comparative Example 1 was performed. The results are shown in Table 3.

Example 2 Talc having an oil absorption of 80 ml / 100 g was added in an amount of 17% by weight to carbonless waste paper, and the same treatment as in Comparative Example 1 was performed. The results are shown in Table 3.

Example 3 The same treatment as in Comparative Example 1 was carried out by adding 17% by weight of precipitated calcium carbonate having an oil absorption of 45 ml / 100 g to waste carbonless paper. The results are shown in Table 3.

Example 4 Clay having an oil absorption of 45 ml / 100 g was added in an amount of 17% by weight to carbonless waste paper, and the same treatment as in Comparative Example 1 was performed. The results are shown in Table 3.

Example 5 A urea resin having an oil absorption of 150 ml / 100 g was added in an amount of 17% by weight with respect to waste carbonless paper, and the same treatment as in Comparative Example 1 was performed. The results are shown in Table 3.

Example 6 Talc having an oil absorption of 80 ml / 100 g was added in an amount of 10% by weight with respect to waste carbonless paper, and the same treatment as in Comparative Example 4 was carried out. The results are shown in Table 3.

Example 7 The same process as in Comparative Example 4 was carried out except that 10% by weight of white carbon having an oil absorption of 190 ml / 100 g was added to the non-carbon waste paper instead of talc. The results are shown in Table 3.
It was shown to.

[0018]

[0019]

[0020]

Remaining ink measurement: Overall magnification 20 times (microscope magnification 0.69 times, camera magnification 29 times) Minimum measurement target is 22 μm or more Remaining ink area ratio: (Measurement remaining ink area / Measurement total area)
× 100 Coarse ink: Ink with an average length of 100 μm or more Average particle size: √ (Average particle area × 4 / π) (Average particle area = total area of remaining ink measured × remaining ink area ratio / total number of remaining ink)

[0022]

As can be seen from Table 3, Examples 1 to 1 of the present invention
7 is excellent in the residual ink area ratio, the number of coarse inks, and the average particle diameter of the residual inks.
P was obtained. On the other hand, in all Comparative Examples, deinking was insufficient.

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[Procedure amendment]

[Submission date] December 6, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art In recent years, from the viewpoint of resource / environmental protection and measures against municipal waste, there is a growing tendency to promote the use of waste paper. A particular problem here is the waste information recording paper discarded from offices and the like. This kind of waste paper is composed of toner prints from electrophotographic copying machines and laser printers, carbonless copy papers, thermal papers, back carbon copy papers, and the like. Of these information recording paper waste papers, carbonless paper, thermal paper, back carbon paper, etc. are so-called contraindicated products, because the DIP obtained when mixed with general waste paper causes coloring and colored spots appear. Has been done. Toner printing material waste paper is macerated, is extremely insufficient deinking a general deinking process comprising a flotation and washing. Thus, it can be said that all the information recording paper waste paper is difficult to deink ink waste paper. For some of the above-mentioned used information recording paper, a single processing method is known.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Regarding a method for independently treating waste carbonless carbon paper, Japanese Patent Publication No. Sho 64-3991, Japanese Patent Laid-Open No. Sho 60-231.
889, JP-A-55-98990, JP-A-55-658
No. 0, JP-A-54-138605 and the like. The toner printing material waste paper, by adding a macerating the used paper a kneader or disperser by treatment step, a known street to the toner ink can be efficiently separated and removed.

Claims (1)

[Claims] 1. An oil absorption amount of 45 ml / 100 g upon deinking of a mixed waste paper containing at least two kinds of waste carbon paper of various kinds of information recording paper and waste paper of toner printed matter.
A method for deinking used paper, which comprises adding the above-mentioned inorganic and / or organic pigments.