JPH04308289A - Deinking - Google Patents

Abstract

PURPOSE:To carry out the subject deinking of high whiteness, high b value and low unremoved ink using simple operations by adding a specified surfactant during break of waste paper and adding a mixture of specified fatty acids during a mixing process after break of waste paper. CONSTITUTION:(A) Deinking is carried out by adding (A) one or more kinds of surfactants selected from (i) a compound of formula (R1 is 8-22C alkyl, alkenyl, etc.; AO is 2-4C alkylene oxide and, in case of presence of two or more kinds of alkylene oxides, may be block polymer chain, etc., p is >=1 corresponding to 800-10000 total molecular weight), (ii) a compound of formula II (R2 is 7-22C alkyl, etc.), (iii) a compound of formula 111 (R3 is 8-24C alkyl, etc.; n is 1-5; M is alkaline metal, etc.) and (iv) a reaction product synthesized by adding an alkylene oxide to a mixture of a natural fat and oil and polyvalent alcohol during break of waste paper and adding (B) a mixture containing 8-24C higher fatty acids or salts thereof so as to satisfy 12.7-22.5 average carbon number, 9.6-70.6wt.% content of 20-24C higher fatty acids, etc., and 45 iodine value during mixing process and/or only flotation process.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking method used for recycling used paper such as newspapers, magazines, and OA used paper. More specifically, when deinking newspapers, magazines, OA waste paper, etc. using the flotation method, washing method, or a combination thereof, it is possible to obtain deinked pulp with high whiteness, high b value, and little unpeeled ink. Regarding the deinking method that can be used.

0002

[Prior art and problems to be solved by the invention] Newspapers,
Recycling of magazines, OA waste paper, etc. has been carried out for a long time, but recently, the effective use of waste paper has become increasingly important, especially in conjunction with global environmental issues such as forest resource protection and garbage disposal. Furthermore, deinked pulp is increasingly being used to produce a higher grade of pulp, as seen in the use of waste newspapers to medium-quality paper. On the other hand, recently used paper is printed using printing technology.
Due to changes in printing methods, printing ink components, etc., the situation is becoming increasingly difficult from the standpoint of deinking. For this reason, improvements have been made to devices to further promote deinking. Chemicals traditionally used to separate and remove ink and other impurities from waste paper include:
Can be used as a deinking agent along with alkaline agents such as caustic soda, sodium silicate, soda carbonate, and sodium phosphate, bleaching agents such as hydrogen peroxide, hyposulfite, and hypochlorite, and sequestering agents such as EDTA and DTPA. , alkylbenzene sulfonates, higher alcohol sulfuric ester salts, α-olefin sulfonates, dialkyl sulfosuccinates, and other anionic activators; higher alcohols, alkylphenols and fatty acid ethylene oxide adducts, alkanolamides, and other nonionic activators. These agents have been used singly or in combination of two or more. However, although these deinking agents have high foaming properties in flotation treatment, their ink collection ability is low, and in addition, their cleaning power is weak in washing methods, and their high foaming properties prevent foaming problems in wastewater treatment. As a result, only low grade deinked pulp was obtained. Furthermore, even with high brightness, it is dull, so there are restrictions on the use of deinked pulp (reducing the amount used under the surface of paperboard, reducing the amount added to newspapers, etc.), and bleaching agents are required to eliminate dullness. The situation forced us to increase usage. In order to obtain deinked pulp that is free from dullness and has a bright tone, it is sufficient to increase the b value of the Hunter color difference Lab display system. Deinked pulp with a high b value indicates a high removal rate of fine ink of 4 μm or less. The higher the b value, the brighter the color tone of the pulp.
It is possible to reduce the amount of bleaching agents such as hydrogen peroxide used, increase the content of deinked pulp, and use it for higher-grade applications.

There are two methods for increasing the b value: either by efficiently removing fine ink of 4 μm or less as described above, or by using a large amount of alkali. However, the latter has the drawbacks of increased stickiness, increased drainage load, and embrittlement of the pulp. Regarding the former technique of collecting and removing fine ink of 4 μm or less, several examples have been given, but none have been effective.

[0004] Higher fatty acids have been known for a long time as deinking agents with high ink collecting ability. For example, Japanese Patent Registration No. 80988, Japanese Patent Registration No. 82089, and Japanese Patent Registration No. 83901 disclose the use as a deinking agent with excellent ink collecting ability when used alone. Also, JP-A-51-13762, JP-A-53-130309, and JP-A-54-6840.
Publication No. 3 discloses that even more excellent effects can be obtained by combined use with other surfactants.

[0005] Subsequently, with the development of technology, a high-performance deinking agent was invented, which is made of a compound to which alkylene oxide such as ethylene oxide or propylene oxide is added, and which can significantly improve the whiteness of deinked pulp (
JP-A-58-109696, JP-A-59-130
Publication No. 400).

However, even if the deinking agents disclosed in these techniques were used, it was not sufficient to obtain deinked pulp with a high b value. Furthermore, when conventionally known higher fatty acids or salts thereof are used, there is a drawback that there is a large amount of unreleased ink and the degree of whiteness is low.

[0007]

[Means for Solving the Problems] The present inventors have demonstrated excellent ink removal ability using the flotation method, washing method, and a hybrid method thereof, and have good operability, especially at high whiteness and high b value. As a result of intensive research to develop a deinking agent that can obtain deinked pulp with less unpeeled ink, it was surprising to find that a certain surfactant was used only during pulping of waste paper, and a specific The present inventors have discovered that the above drawbacks can be overcome by adding a mixture of higher fatty acids or salts thereof only to the mixing step and/or flotation step after the pulping step, and have completed the present invention.

That is, the present invention provides the following general formula (a-1)
1 selected from the group consisting of compounds represented by (a-3) and reaction products (a-4) obtained by adding alkylene oxide to a mixture of natural oils and fats and polyhydric alcohols
(b) higher fatty acids having 8 to 24 carbon atoms or their salts in a range with an average carbon number of 12.7 to 22.5; , the content of higher fatty acids having 20 to 24 carbon atoms or their salts is 9.6 to 70.6% by weight, and the iodine value (I
The present invention provides a deinking method characterized in that a mixture having V) of 45 or less is added only to the mixing step and/or flotation step after the pulping step. R1-O-(-AO-)p-H
(a-1) [In the formula, R1 represents an alkyl group or alkenyl group having 8 to 24 carbon atoms, or an alkylphenyl group having an alkyl group having 6 to 14 carbon atoms, and AO is an alkyl group having 2 to 24 carbon atoms.
~4 alkylene oxide, when two or more types of alkylene oxides are present, it may be a block polymer chain or a random polymer chain, and p has an overall molecular weight of 800~
It is a number greater than or equal to 10000. ] R2-COO-(-AO-)m-H
(a-2) [In the formula, R2 represents an alkyl group or alkenyl group having 7 to 23 carbon atoms, AO is an alkylene oxide having 2 to 4 carbon atoms, and when two or more types of alkylene oxide are present, a block It may be a polymer chain or a random polymer chain, and m has an overall molecular weight of 800 to 10,000.
It is a number greater than or equal to 1. ] R3-O-(-AO-)n-SO3M
(a-3) [In the formula, R3 is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, a cycloalkyl group, or a cycloalkyl group having 8 to 12 carbon atoms.
represents an alkylphenyl group having an alkyl group of AO
is an alkylene oxide having 2 to 4 carbon atoms, and when two or more types of alkylene oxide are present, it may be a block polymer chain or a random polymer chain, n is 1 to 5, and M represents an alkali metal or ammonium. ] The numerical specifications regarding compounds (a-1) to (a-4) according to the present invention are critical, and even if there are similar compounds, those that do not fall under the provisions of the present invention are considered to be particularly important in the present invention. No effect can be obtained. Therefore, limitations on the functional groups or numerical values represented by general formulas (a-1) to (a-3) are extremely important. When R1 in the general formula (a-1) is an alkyl group or an alkenyl group, if the number of carbon atoms is less than 8, the ink collecting ability will be weak and it will be impossible to obtain a deinked pulp with high whiteness. When the number of carbon atoms exceeds 24, the releasability of ink from cellulose decreases, so that a large amount of unremoved ink remains, resulting in deinked pulp with poor appearance.

Further, the compound represented by the general formula (a-1) is produced by adding alkylene oxide to alcohol by a conventionally known method, and the total molecular weight of the alkylene oxide adduct to alcohol is 800. ~100
00, preferably in the range of 1000 to 4000. This molecular weight is a number average molecular weight determined by GPC (gel permeation chromatography) as a polyethylene glycol equivalent molecular weight. If the molecular weight is less than 800, the ink scavenging ability will be weak and a deinked pulp with high whiteness cannot be obtained. On the other hand, the molecular weight is 1000
If it exceeds 0, the ability to form bubbles on the liquid surface of the flotator is weak, making it difficult for the aggregated ink to be rejected by the flotator, and as a result, only deinked pulp with low whiteness can be obtained.

As the alkylene oxide to be added to the alcohol, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), and butylene oxide (hereinafter abbreviated as BO) can be used alone or in combination. Particularly preferred is a mixture of EO and PO, the molar ratio of which is EO/PO=0.5/1 to 3/1. Furthermore, in order to reduce foaming troubles in the papermaking process and wastewater treatment process, random addition is a good method for adding alkylene oxide.

[0011] The alcohol used for producing the compound represented by the general formula (a-1) has 8 to 8 carbon atoms.
Those having 24 alkyl or alkenyl groups, or those having an alkylphenyl group having an alkyl group having 6 to 14 carbon atoms. Specific examples include 1-octanol, 1-nonanol, 1-decanol, 1- undecanol, 1-dodecanol, 1-tridecanol, 1
-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-icosanol, 1-
Henicosanol, 1-docosanol, 1-tricosanol, 1-tetracosanol, 2-octanol, 2-
nonanol, 2-decanol, 2-undecanol, 2
-dodecanol, 2-tridecanol, 2-tetradecanol, 2-pentadecanol, 2-hexadecanol, 2-heptadecanol, 2-octadecanol, 2-
Nonadecanol, 2-icosanol, 2-octene-1
-ol, 2-dodecen-1-ol, 2-undecen-1-ol, 2-tetradecen-1-ol, 2-pentadecen-1-ol, 2-hexadecen-1-ol, 2-octadecen-1-ol , 8-nonene-1-
ol, 10-undecen-1-ol, 11-dodecen-1-ol, 12-tridecen-1-ol, 15
-hexadecen-1-ol, oleyl alcohol, elaidyl alcohol, linoleyl alcohol, linolenyl alcohol, eleostearyl alcohol, ricinoyl alcohol, cyclononanol, cyclodecanol,
Cycloundecanol, cyclododecanol, cyclotridecanol, cyclotetradecanol, cyclopentadecanol, cyclohexadecanol, cycloheptadecanol, cyclooctadecanol, cyclononadecanol, cyclocosanol, octylphenol, Examples include nonylphenol.

The compound represented by the general formula (a-1) is preferably one in which R1 has 14 to 24 carbon atoms, and more preferably R1 is an alkyl group.

When the number of carbon atoms in R2 of the compound represented by the general formula (a-2) according to the present invention is less than 7, the ink collecting ability is weak and it is impossible to obtain a deinked pulp with high whiteness. Furthermore, when the number of carbon atoms in R exceeds 24, the releasability of ink from cellulose decreases, so that a large amount of unremoved ink remains, resulting in deinked pulp with poor appearance.

Further, the compound represented by the general formula (a-2) is produced by adding alkylene oxide to a fatty acid by a conventionally known method, and the compound represented by the general formula (a-1) As in the case of , it is important that the total molecular weight of the alkylene oxide adduct to the fatty acid is in the range of 800 to 10,000, preferably 1,000 to 4,000. If the molecular weight is less than 800, the ink scavenging ability will be weak and a deinked pulp with high whiteness cannot be obtained. On the other hand, when the molecular weight exceeds 10,000, the ability to form bubbles on the liquid surface of the flotator is weak, making it difficult for the aggregated ink to be rejected by the flotator, and as a result, only deinked pulp with low whiteness can be obtained.

[0015] As the alkylene oxide to be added to the fatty acid, EO, PO, and BO can be used alone or in combination. Particularly preferred is a mixture of EO and PO, the molar ratio of which is EO/PO=0.5/1 to 3/1. Furthermore, in order to reduce foaming troubles in the papermaking process and wastewater treatment process, random addition is a good method for adding alkylene oxide.

[0016] The fatty acid used to produce the compound represented by general formula (a-2) is one in which the portion corresponding to R2 has 7 to 23 carbon atoms. , caprylic acid, pelargonic acid, capric acid,
Undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, elaidic acid, linoleic acid,
Linoleic acid, stearolic acid, ricinoleic acid, ricinoelaidic acid, nonadecanoic acid, arachidic acid, henicosanoic acid, behenic acid, brassicic acid, erucic acid, tricosanoic acid, tetracosanoic acid, coconut oil fatty acid, tallow fatty acid, palm oil fatty acid, Mention may be made of tall oil fatty acids, rapeseed oil fatty acids, fish oil fatty acids, and the like.

The compound represented by the general formula (a-2) is preferably one in which R2 has 11 to 23 carbon atoms, and more preferably R2 is an alkyl group.

It is important that the number of carbon atoms in R3 of the compound represented by the general formula (a-3) according to the present invention is in the range of 8 to 24. If the number of carbon atoms in R3 is less than 8, the ink scavenging property will be low and a deinked pulp with high whiteness will not be obtained. Also,
When the number of carbon atoms in R3 exceeds 24, the releasability of ink from cellulose decreases, resulting in a large amount of unremoved ink remaining, resulting in deinked pulp with poor appearance. Furthermore, the same applies to alkylphenyl groups having an alkyl group having 8 to 12 carbon atoms, and if the alkyl group has less than 8 carbon atoms, the ink scavenging property is low and a deinked pulp with high whiteness cannot be obtained. Furthermore, if the number of carbon atoms in the alkyl group exceeds 12, there will be a large amount of unreleased ink, and only deinked pulp with poor appearance will be obtained.

The compound represented by the general formula (a-3) can be prepared by a conventionally known method to obtain an alcohol having an alkyl group or alkenyl group having 8 to 24 carbon atoms, or an alkylphenyl group having an alkyl group having 8 to 12 carbon atoms. It can be obtained by adding alkylene oxide to, followed by sulfonation and neutralization. The alkyl group may be linear or cyclic. Specific examples of such alcohols include 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-icosanol, 1-heicosanol, 1-docosanol, 1-tricosanol, 1-tetracosanol, 2-octanol, 2-nonanol, 2-decanol, 2-undecanol, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-pentadecanol, 2-
hexadecanol, 2-heptadecanol, 2-octadecanol, 2-nonadecanol, 2-icosanol,
2-henicosanol, 2-docosanol, 2-tricosanol, 2-tetracosanol, 2-octene-1-
All, 2-dodecen-1-ol, 2-undecen-
1-ol, 2-tetradecen-1-ol, 2-pentadecen-1-ol, 2-hexadecen-1-ol, 2-octadecen-1-ol, 8-nonen-1-ol, 10-undecen-1-ol ol, 11-dodecen-1-ol, 12-tridecen-1-ol, 15-
Hexadecen-1-ol, oleyl alcohol, elaidyl alcohol, linoleyl alcohol, linolenyl alcohol, eleostearyl alcohol, ricinoyl alcohol, cyclononanol, cyclodecanol, cycloundecanol, cyclododecanol, cyclotri Examples include decanol, cyclotetradecanol, cyclopentadecanol, cyclohexadecanol, cycloheptadecanol, cyclooctadecanol, cyclononadecanol, cyclocosanol, octylphenol, nonylphenol, and the like. The alcohol preferably has an alkyl group.

As the alkylene oxide to be added to the alcohol, EO, PO, and BO can be used alone or in combination. Particularly preferred is a mixture of EO and PO, the molar ratio of which is EO/PO=1/1 to 5/1. Also,
The number of moles of alkylene oxide added is preferably 1 to 5 moles. When the number of moles added is less than 1, the foam forming power on the liquid surface of the flotator is small, so that the flotator rejects the agglomerated ink insufficiently, and as a result, only deinked pulp with low whiteness is obtained. In addition, if the number of added moles exceeds 5, the foam removal properties of the flotation reject will deteriorate.
Backflow of flotation rejects into the flotator cell occurs, resulting in low deinking rate, low whiteness,
Only deinked pulp with low b value can be obtained.

In the general formula (a-3), M represents an alkali metal such as sodium or potassium or ammonium.

Component (a-4) according to the present invention is an alkylene oxide adduct of a mixture of natural oil and fat and polyhydric alcohol. The mixing ratio of natural oil and fat and polyhydric alcohol, the number of moles of alkylene oxide added, etc. of component (a-4) of the present invention are extremely important. It is desirable to add 5 moles or more of alkylene oxide to 1 mole of natural oil or fat. Particularly preferred is 20 to 100 mol. If the number of moles of alkylene oxide added is less than 5 moles, foaming properties during flotation will be insufficient, and the agglomerated ink will be difficult to be smoothly rejected out of the system. As a result, only deinked pulp with low whiteness can be obtained. The mixing ratio of natural oil and fat and polyhydric alcohol is preferably 1/0.1 to 1/3 in molar ratio of natural oil and fat/polyhydric alcohol. Particularly preferably 1/0.2 to 1/2. This molar ratio is 1/
If it exceeds 0.1, foaming properties during flotation will be insufficient, making it difficult for the agglomerated ink to be smoothly rejected out of the system. As a result, only deinked pulp with low whiteness may be obtained. Furthermore, if the molar ratio is less than 1/3, the flotation rejects will flow back into the flotator cell, resulting in a low deinking rate and only deinked pulp with low whiteness and low b value can be obtained. There are cases.

[0023] The alkylene oxide to be added to the mixture of the natural oil and fat and polyhydric alcohol may be EO, PO, BO, etc., singly or in combination. Particularly preferred are EO and PO. As methods for adding alkylene oxide, there are a method in which different types of alkylene oxides are mixed and added (random addition), or sequentially added (block addition). Although any method of addition may be used, random addition is preferred, especially in view of foaming problems in the papermaking process and wastewater treatment process.

Natural oils and fats used in component (a-4) of 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; Examples include fish oils, hydrogenated oils and semi-hardened oils thereof, and recovered oils obtained in the refining process of these oils and fats.

Further, as the polyhydric alcohol used in component (a-4) of the present invention, ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, 1,6-hexane glycol, 2-ethylbutane-1,2 ,3-triol, glycerin, trimethylolpropane, trimethylolethane, 1,2
, 4-butanetriol, 1,2,6-hexanetriol, 1,1,1-trimethylolhexane, tetramethylolcyclohexanol, diglycerin, mannitan, pentaerythritol, erythritol, arabitol, sorbitol, D-glycero-D -galactoheptose, D-glycero-D-glucoheptose,
D-glycero-D-mannoheptose, D-glycero-L-mannoheptose, D-altroheptulose, D-mannoheptulose, D-altro-
3-heptulose, D-glycero-D-galaheptitol, D-erythro-D-galaoctitol, D
-glycero-D-mannooctulose, D-erythro-L-gulononurose, cellobiose, maltose, lactose, gentianose, cellotriose, stachyose and the like. Particularly preferred are dihydric to hexahydric alcohols.

The numerical specifications regarding the fatty acid mixture of component (b) related to the present invention are critical, and even compounds similar to this, which do not fall under the provisions of the present invention, will not have the significant effects of the present invention. I can't get it. Therefore, numerical limitations such as limitations on the number of carbon atoms in the compound of the present invention are extremely important. As will be clarified by the Examples and Comparative Examples described below, if the average carbon number is smaller than 12.7, the fine ink aggregation effect will be reduced, making it impossible to obtain a deinked pulp with a high b value. Further, even if the average carbon number exceeds 22.5, the foaming property in the flotation step is insufficient, and the agglomerated ink is difficult to be rejected out of the system. Furthermore, if the content of fatty acids having 20 to 24 carbon atoms is less than 9.6% by weight, the fine ink aggregation effect is reduced, making it impossible to obtain deinked pulp with a high b value. On the other hand, if it is greater than 70.6% by weight, the ink releasability becomes weak and a large amount of unremoved ink remains, resulting in
Only deinked pulp with poor appearance is obtained. The compound of the present invention may contain any fatty acid having 8 to 24 carbon atoms within the scope of the present invention. In particular, 2 fatty acids with 20 carbon atoms or their salts.
．． 0 to 33.2% by weight of fatty acids having 22 carbon atoms 9
．． The content is preferably 5 to 32.0% by weight.

Furthermore, if the iodine value (IV) is higher than 45, the foaming property in the flotation process will be insufficient, and the agglomerated ink on the foam layer will be difficult to be rejected out of the system, resulting in the removal of low whiteness. Only ink pulp can be obtained. Furthermore, since the ink removability is low, a large amount of unremovable ink remains.

As described above, the component (b) of the present invention can include any fatty acid having 8 to 24 carbon atoms and its salt within the scope of the present invention, but specifically, caprylic acid, pelargonic acid, Capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, elaidic acid, linoleic acid, linoleic acid, stearolic acid, ricinoleic acid, ricinoelaidic acid , nonadecanoic acid, arachidic acid, henicosanoic acid, behenic acid, brassicic acid,
Erucic acid, tricosanoic acid, tetracosanoic acid, coconut oil, fatty acids, beef tallow fatty acids, palm oil fatty acids, tall oil fatty acids,
Mention may be made of rapeseed oil fatty acids, fish oil fatty acids, semi-hardened or hardened fatty acids thereof, and salts of all these fatty acids. Examples of the salt include sodium salt, potassium salt, ammonium salt, magnesium salt, calcium salt, and the like. Among these, semi-hardened or hardened fish oil fatty acids or salts thereof are preferred from the viewpoint of cost and ease of use alone. Examples of the fish oil that is a raw material for the fish oil fatty acid of the present invention include cod oil, sardine oil, saury oil, mackerel oil, herring oil, menhaden oil, and recovered oil obtained in the refining process of these oils.

Although it has been known in the prior art that higher fatty acids are used as a deinking agent, it is completely unknown that such a deinking effect is exhibited only by a mixture containing fatty acids with a specific number of carbon atoms in a specific ratio. It wasn't. In other words, the prior art merely uses anionic surfactants derived from coconut oil or tallow oil, or higher fatty acids commonly used as raw materials thereof, without regard to the number of carbon atoms. The prior art does not disclose the use of higher fatty acids in a specific ratio. Even in the above patent publications, there are almost no examples in which the fatty acid mixture disclosed in the present invention is used. Furthermore, these mainly contain fatty acids having 12 to 18 carbon atoms, which are clearly different from the scope of the present invention.

One of the fatty acids used in the present invention is fish oil fatty acids or salts thereof. Prior art Japanese Patent Application Laid-Open No. 61-89394, Japanese Patent Application Laid-Open No. 62-250291
Although the publication describes the combined use of fish oil fatty acids containing fatty acids having a carbon number of 20 or more, no specific examples are described, and the effect of increasing the b value by removing fine ink of 4 μm or less according to the present invention is not clear. It has a different effect. Furthermore, it is essential for the present invention to have a specific iodine value (IV), and the fish oil fatty acid of the prior art has an iodine value (IV) of approximately 175, and the fish oil fatty acid itself has an iodine value (IV) of approximately 175. It is too expensive to be used for this purpose.

Component (b) of the present invention exhibits a sufficient deinking effect even when used alone, so it is not necessary to use other surfactants in combination or to add alkylene oxide. Therefore, the present invention discloses an invention that is extremely useful industrially, not only in terms of deinking performance but also in simplifying processes such as manufacturing and compounding a deinking agent, thereby improving versatility and safety.

Most of the fatty acids constituting component (b) of the present invention are derived from natural oils and fats, and the method for producing fatty acids is the conventionally known technology Twitchell.
There are decomposition, medium pressure catalytic decomposition, and continuous high pressure decomposition methods. Further, as a general method of lowering the iodine value (IV), there can be mentioned a method of hydrogenation using a nickel catalyst under high temperature and high pressure.

Components (a-1) to (a-4) according to the present invention are used only during pulping of waste paper, and (b)
Excellent effects can be obtained by adding the component only to the mixing step and/or flotation step after the pulping step. Although it is possible to obtain deinked pulp of a certain level of quality by mixing the components (a) and (b) or by reversing the timing of their addition, the method of the present invention can produce deinked pulp of even higher quality, that is, with higher whiteness. The present invention discloses that it is possible to obtain deinked pulp with a high b value and a small amount of unreleased ink.

Components (a-1) to (a-4) and (b)
The addition ratio of components is also important. That is, in terms of weight ratio, (a-1)/(b) = 10/90 to 90/10, respectively.
Preferably 40/60 to 60/40, (a-2)/(b
) = 10/90 to 90/10, preferably 40/60
~60/40, (a-3)/(b) =5/95~30
/70, preferably 10/90 to 25/75, (a-4
)/(b) = 10/90 to 70/30, preferably 2
0/80 to 50/50 is preferable. If the weight ratio is above the minimum value,
The ink releasability from cellulose is further improved, and as a result, the amount of unremovable ink remaining is reduced. On the other hand, if the weight ratio is below the maximum value, it is possible to obtain a deinked pulp with strong ink scavenging properties, high whiteness, and high b value. Especially (a-3)
In the case of the weight ratio of /(b), if it is below the maximum value, the foam removal property of the flotation reject will be very good, so it will be very difficult for the flotation reject to flow back into the flotator cell. The inking ratio becomes high, and a deinked pulp with high whiteness and high b value can be obtained.

Component (a) and (b) according to the present invention
The sum of the added amounts of the components is preferably within a range that does not impair operability and is economical, but it is preferably 0.03 to 1.0% by weight based on the raw material waste paper.

[0036]

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto.

Examples 1 to 5 The present examples are examples of adding a deinking agent in a pulping process and a chemical mixing process separately. Municipally collected newspaper 2 x 5 cm
After shredding, put a certain amount of it into a tabletop disintegrator, and add water, 0.2% caustic soda (based on raw materials), and the specified amount of deinking agent shown in Table 1 and/or Table 2 to determine the pulp density. 15%,
After decomposition at 45°C for 12 minutes, aging treatment was performed at 55°C for 120 minutes. After that, it was dehydrated to 23% in a high-speed dehydrator, and 0.6% of caustic soda (based on raw materials) and sodium silicate No. 3 (
2.2% (based on raw materials), 30% hydrogen peroxide (based on raw materials) 3.
5%, add the specified amount of deinking agent shown in Table 1 and/or Table 2, adjust the pulp concentration to 22% with water, and mix with a tabletop disintegrator.
Mixed for a minute. Thereafter, kneading treatment was performed using a two-screw lab kneader with a rotational speed of 300 rpm. Then, add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. The slurry was diluted to 1% with water and then subjected to flotation treatment at 30°C for 10 minutes. In addition, CaCl2 (relative to raw material) 0.4 during flotation
% added. 8 Pulp slurry after flotation
After concentrating to a concentration of 4% using a 0-mesh wire, water was added to dilute to a concentration of 1%, and a pulp sheet was produced using a Tappy standard paper machine. The hardness of the water used was 5°d.
The hardness was adjusted to Ca/Mg=8/2 (molar ratio) using CaCl2 and MgCl2. The whiteness and b value of the obtained pulp sheet were measured using a colorimeter and the number of unpeeled inks was measured using an image analyzer (x100 magnification). The b value here refers to the b value in the Hunter color difference Lab color system, and is the tristimulus value XYZ.
The relationship with is shown below.

[0038]

[Math 1]

As can be seen from this equation, the b value is a function of Y and Z, and a positive value indicates the intensity of yellowness, and a negative value indicates the intensity of bluishness. Table 3 shows the deinking performance of various deinking methods. In addition, the higher fatty acid mixture in Table 2 is No. All fatty acids α to δ are blended to have a predetermined carbon number composition.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

Examples 6 to 10 The present examples and comparative examples are examples in which the deinking agent is added separately in the pulping process and the kneading process. 2x5 municipally collected newspapers
After shredding into cm pieces, put a certain amount of it into a tabletop disintegrator, add water and 0.2% caustic soda (based on raw materials), Table 4 and /
Or add the specified amount of deinking agent shown in Table 5 to make the pulp density 15.
After decomposition at 45°C for 12 minutes, aging treatment was performed at 55°C for 120 minutes. After that, it was dehydrated to 23% in a high-speed dehydrator, and caustic soda (
(based on raw materials) 0.6%, Sodium silicate No. 3 (based on raw materials) 2.2
%, 30% hydrogen peroxide (based on the raw material), 3.5%, deinking agent shown in Table 4 and/or Table 5 (based on the raw material) 0.2%, adjusted to a pulp concentration of 22% with water, and prepared on a tabletop. The mixture was mixed for 1 minute using a disintegrator. Thereafter, kneading treatment was performed using a two-screw lab kneader with a rotational speed of 300 rpm. Then, add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. The slurry was diluted to 1% with water and then subjected to flotation treatment at 30°C for 10 minutes. Incidentally, 0.5% of CaCl2 (based on the raw material) was added during flotation. The pulp slurry after flotation was concentrated to a concentration of 4% using an 80 mesh wire, diluted to a concentration of 1% by adding water, and a pulp sheet was produced using a Tappy standard paper machine. The hardness of the water used was 10°dH, and the hardness was CaCl2, MgCl2, Ca/
Adjustment was made so that Mg=8/2 (molar ratio). The whiteness and b value of the obtained pulp sheet were measured using a colorimeter and the number of unpeeled inks was measured using an image analyzer (x100 magnification). Table 6 shows the deinking performance of various deinking methods. In addition, the higher fatty acids that are one of the components of the deinking agent in Table 5 are:
No. ε to η are hydrogenated products of sardine, saury, and mackerel oil fatty acids, respectively. Furthermore, θ and ι are stearic acid and sardine oil fatty acid (iodine value (IV)=175), respectively.

[0044]

[Table 4]

[0045]

[Table 5]

[0046]

[Table 6]

Examples 11 to 19 The present examples and comparative examples are examples in which a deinking agent is added in portions before the pulping process and the flotation process. 2 municipally collected newspapers
After shredding into 5 cm pieces, put a certain amount of it into a tabletop disintegrator, add water, 0.2% caustic soda (based on raw materials), and a certain amount of deinking agent shown in Table 7 and/or Table 8, Pulp concentration 15%, after 12 minutes of disintegration at 45℃, 120 minutes at 55℃
Aging treatment was performed for 1 minute. After that, it was dehydrated to 23% in a high-speed dehydrator, and 0.6% caustic soda (based on the raw material), 2.2% sodium silicate No. 3 (based on the raw material), and 3.5% hydrogen peroxide (based on the raw material) were added. In addition, the pulp concentration was adjusted to 22% with water and mixed for 1 minute using a tabletop disintegrator. After that, the rotation speed is 30
Kneading treatment was performed using a twin-screw lab kneader at 0 rpm. Then, add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. After adding a predetermined amount of the deinking agent shown in Table 7 and/or Table 8 to the pulp slurry, the slurry was diluted to 1% with water, and then subjected to flotation treatment at 30° C. for 10 minutes. The pulp slurry after flotation was concentrated with a 60 mesh wire to a concentration of 4%, water was added to dilute it to a concentration of 1%, and a pulp sheet was produced using a Tappy standard paper machine. The hardness of the water used was 40°dH, and the hardness was that of CaCl2, Mg
Using Cl2, the mixture was adjusted to Ca/Mg=8/2 (molar ratio). The whiteness and b value of the obtained pulp sheet were measured using a colorimeter and the number of unpeeled inks was measured using an image analyzer (x100 magnification). Table 9 shows the deinking performance of various deinking methods. In addition, all the higher fatty acid mixtures in Table 8 are sodium salts. Also, No. κ to π are obtained by blending single fatty acid sodium salts to have a predetermined carbon number composition.

[0048]

[Table 7]

[0049]

[Table 8]

[0050]

[Table 9]

[0051]

[Table 10]

As exemplified above, general formula (a-1) ~
One or more surfactants selected from the group consisting of the compound represented by (a-3) and the reaction product (a-4) obtained by adding alkylene oxide to a mixture of natural oils and fats and polyhydric alcohols. It is added only during pulping of waste paper, and contains higher fatty acids having 8 to 24 carbon atoms or their salts with an average carbon number of 12.7 to 22.5, and higher fatty acids having 20 to 24 carbon atoms. Or its salt content is 9.6
~70.6% by weight, and an iodine value (IV) of 45
By adding the following mixture only to the mixing step and/or flotation step after the pulping step, preferably at a certain ratio, deinked pulp with high whiteness, high b value, and less unpeeled ink can be obtained. be able to.

Claims (6)

[Claims] Claim 1: (a) The following general formulas (a-1) to (a-3
), and one or more surfactants selected from the group consisting of the reaction product (a-4) obtained by adding alkylene oxide to a mixture of natural oils and fats and polyhydric alcohols, using waste paper disintegration ( pulping) and (b)
) Higher fatty acids having 8 to 24 carbon atoms or salts thereof are contained in a range where the average number of carbon atoms is 12.7 to 22.5, and the content of higher fatty acids having 20 to 24 carbon atoms or salts thereof is 9.6.
~70.6% by weight, and an iodine value (IV) of 45
A deinking method characterized in that the following mixture is added only to the mixing step and/or flotation step after the pulping step. R1-O-(-AO-)p-H
(a-1) [In the formula, R1 represents an alkyl group or alkenyl group having 8 to 24 carbon atoms, or an alkylphenyl group having an alkyl group having 6 to 14 carbon atoms, and AO is an alkyl group having 2 to 24 carbon atoms.
~4 alkylene oxide, when two or more types of alkylene oxides are present, it may be a block polymer chain or a random polymer chain, and p has an overall molecular weight of 800~
It is a number greater than or equal to 10000. ] R2-COO-(-AO-)m-H
(a-2) [In the formula, R2 represents an alkyl group or alkenyl group having 7 to 23 carbon atoms, AO is an alkylene oxide having 2 to 4 carbon atoms, and when two or more types of alkylene oxide are present, a block It may be a polymer chain or a random polymer chain, and m has an overall molecular weight of 800 to 10,000.
It is a number greater than or equal to 1. ] R3-O-(-AO-)n-SO3M
(a-3) [In the formula, R3 is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, a cycloalkyl group, or a cycloalkyl group having 8 to 12 carbon atoms.
represents an alkylphenyl group having an alkyl group of AO
is an alkylene oxide having 2 to 4 carbon atoms, and when two or more types of alkylene oxide are present, it may be a block polymer chain or a random polymer chain, n is 1 to 5, and M represents an alkali metal or ammonium. ] 2. The deinking method according to claim 1, wherein the reaction product (a-4) is obtained by adding 5 moles or more of alkylene oxide to 1 mole of natural oil or fat. Claim 3: Claim 1, wherein the mixing ratio of the mixture of natural oil and fat and polyhydric alcohol is 1/0.1 to 1/3 in molar ratio.
Or the deinking method described in 2. 4. A claim in which the component (b) contains 2.0 to 33.2% by weight of a fatty acid having 20 carbon atoms or a salt thereof, and 9.5 to 32.0% by weight of a fatty acid having 22 carbon atoms. 1~
3. The deinking method described in any one of 3. 5. The deinking method according to claim 1, wherein the higher fatty acid having 8 to 24 carbon atoms or a salt thereof is a semi-hardened or hardened fish oil fatty acid or a salt thereof. [Claim 6] The weight ratio of components (a-1) to (a-4) and component (b) is (a-1)/(b) = 10/90 to 90/10, ( a
-2)/(b) =10/90~90/10, (a-3
)/(b) =5/95~30/70, (a-4)/(
b) Claim 1 in the range of =10/90 to 70/30
5. The deinking method according to any one of items 5 to 5.