JPH04281084A - Deinking agent - Google Patents

Abstract

PURPOSE:To obtain a deinking agent, containing a mixture of higher fatty acids (salt) and a specific polyalkylene glycol in a constant proportion and capable of providing deinked pulp having a high whiteness and high (b) value with hardly any unpeeled ink. CONSTITUTION:A deinking agent containing (A) a mixture, containing 8-24C higher fatty acids (salts) such as caprylic acid or pelargonic acid within a range so as to afford 12.7-22.5 average number of carbon atoms and having 9.6-70.6wt.% content of the 20-24C higher fatty acids (salts) and <=45 iodine value and (B) a compound expressed by the formula [R is 8-24C alkyl, alkenyl or alkylphenyl having a 6-14C alkyl group; AO is 2-4C alkylene oxide and may be a block or a random polymerization chain if >=2 kinds of alkylene oxides are present; (1) is a number of >=1 so as to provide the whole with 800-10000 molecular weight] at (90/10) to (40/60) weight ratio of the components [(A)/(B)]. The aforementioned deinking agent exhibits excellent ink removing ability and is improved in operating efficiency.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking agent 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 deinking agents 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:
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. Anionic activators such as alkylbenzene sulfonates, higher alcohol sulfate ester salts, α-olefin sulfonates, dialkyl sulfosuccinates, nonionic activators such as higher alcohols, ethylene oxide adducts of alkylphenols and fatty acids, and alkanolamides. 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
400).

However, even when using the deinking agents disclosed in these techniques, it has not been possible 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 yield deinked pulp with less unremoved ink, surprisingly, a mixture of higher fatty acids having 8 to 24 carbon atoms or their salts was found. The average carbon number of the fatty acids or salts thereof is in the range of 12.7 to 22.5, and the content of higher fatty acids having 20 to 24 carbon atoms or salts thereof is 9.6 to 70.6% by weight, In addition, the inventors discovered that a deinking agent obtained by using a mixture having an iodine value (IV) of 45 or less and a specific surfactant in a specific weight ratio can overcome the above drawbacks, and have completed the present invention. Ta.

That is, the present invention provides: (a) higher fatty acids having 8 to 24 carbon atoms or salts thereof with an average carbon number of 12.7 to 22.5; The content of fatty acids or their salts is 9
．． 6 to 70.6% by weight and an iodine value (IV) of 45 or less, and (b) the following general formula (1)
The compound R-O-(-AO-)l-H represented by
(1) [In the formula, R 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 represents an alkyl group having 2 to 24 carbon atoms.
When two or more types of alkylene oxides are present in the alkylene oxide of 4, it may be a block polymer chain or a random polymer chain, and l is an overall molecular weight of 800 to 1.
It is a number greater than or equal to 0000. ] in weight ratio (
The present invention provides a deinking agent characterized in that it contains a)/(b) in a ratio of 90/10 to 40/60, preferably 85/15 to 50/50.

(a) The numerical specifications regarding the components are critical, and even if the compound is similar, it will not be possible to obtain the remarkable effects of the present invention if it does not fall under the specifications of the present invention. 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. Also, the number of carbon atoms is 2
When the content of fatty acids 0 to 24 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 more than 70.6% by weight, the ink releasability becomes weak and a large amount of unremoved ink remains, resulting in deinked pulp with poor appearance. 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, it is preferable to contain 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. In addition, (a) the iodine value (IV) of the component;
If it is larger than 45, the foamability in the flotation step is insufficient, and the agglomerated ink on the foam layer is difficult to be rejected out of the system, and as a result, only deinked pulp with low whiteness can be obtained. Furthermore, since the ink removability is low, a large amount of unremovable ink may remain in some cases.

As mentioned above, fatty acids having 8 to 24 carbon atoms and their salts can be optionally blended into the component (a) of the present invention within the scope of the present invention, but specifically, caprylic acid, pelargonic acid, etc. , 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, brassic acid, erucic acid, tricosanoic acid, tetracosanoic acid, coconut oil fatty acid, beef tallow fatty acid, palm oil fatty acid, tall oil fatty acid,
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.

[0011] 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 having 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 or salts thereof used in the mixture of higher fatty acids or salts thereof which is component (a) of the present invention is fish oil fatty acids or salts thereof. Prior art JP-A-61-89394, JP-A-62-
Although Publication No. 250291 describes the combined use of fish oil fatty acids containing fatty acids with carbon atoms 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 described. suggests 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.
Fish oil fatty acids themselves cannot be used for this purpose because their iodine value (IV) is too high.

Most of the fatty acids constituting component (a) of the present invention are derived from natural oils and fats, and the method for producing fatty acids is the conventionally known technique of 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.

On the other hand, the compound represented by the general formula (1), which is the component (b) of the present invention, can be prepared by a conventionally known method to form an alkyl group or alkenyl group having 8 to 24 carbon atoms, or an alkyl group having 6 to 14 carbon atoms. It is produced by adding alkylene oxide to an alcohol having an alkylphenyl group having an alkyl group. 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-octen-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-nonen-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,
Examples include cyclononadecanol, cyclocosanol, octylphenol, and nonylphenol.

The compound represented by the general formula (1) is preferably one in which R has 14 to 24 carbon atoms,
More preferably R is an alkyl group. (b)
The numerical specifications regarding the compound represented by the general formula (1), which is a component, are also critical, and even if the compound is similar to this, it will not be able to obtain the significant effects of the present invention if it does not fall under the provisions of the present invention. I can't do it. Therefore, limiting the functional groups or numerical values represented by general formula (1) is extremely important. As will be clarified by the Examples and Comparative Examples described later, when the number of carbon atoms in R in the general formula (1) is 7 or less, 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 is 25 or more, the releasability of ink from cellulose becomes low, so that a large amount of unremoved ink remains, and only deinked pulp with poor appearance can be obtained.

It is also important that the total molecular weight of the alkylene oxide adduct of alcohol is in the range of 800 to 10,000, preferably 1,000 to 4,000. 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, 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.

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.

In the present invention, (a) component and (b)
The mixing ratio of the components is (a)/(b) = 90 by weight
It is also important that the ratio is in the range of /10 to 40/60. If the weight ratio is greater than 90/10, 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. . Also, the weight ratio is 40
If the value is smaller than /60, the flotation reject will have poor bubble removal properties, causing the flotation reject to flow back into the flotator cell, resulting in a low deinking rate, resulting in low whiteness and low b value. Only ink pulp can be obtained.

The deinking agent of the present invention is a known deinking agent, such as higher alcohol sulfates, alkylbenzene sulfonates, ethylene oxide adducts of higher alcohols and alkylphenols other than those of the present invention, fatty acids and their salts, fatty acid alkylenes. Even when used in combination with oxide adducts, fat and oil alkylene oxide adducts, monostearylglyceride alkylene oxide adducts, polyhydric alcohol partial esters or complete ester alkylene oxide adducts, the weight ratio of component (a) and component (b) is (a)
/(b) = within the range of 90/10 to 40/60, excellent deinking performance is exhibited. When the deinking agent of the present invention and a conventionally known deinking agent are used together, the ratio of the present invention/conventional product is preferably 90/10 to 10/90 (weight ratio), particularly preferably 20 /80~60/40(
weight ratio).

[0020] The amount of the deinking agent of the present invention to be added is preferably within an economical range that does not impair operability.
．． 03 to 1.0% by weight is preferred.

[0021]

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

Example 1 This example is an example of adding a deinking agent all at once during the pulping process. 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) 0.8%, and silicate soda No. 3 (based on raw materials) 2.2%. %
, 30% hydrogen peroxide (based on the raw material), 3.5%, and the deinking agent shown in Tables 1 to 3 (based on the raw material) 0.5% were added, and the pulp density was 1.
5%, decomposed at 45°C for 12 minutes, then at 55°C 120
Aging treatment was performed for 1 minute. Thereafter, it was dehydrated to 23% using a high-speed dehydrator, and kneaded using a twin-screw lab kneader with a rotational speed of 300 rpm. Then add water to 4%
Dilute to 50% 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. After the pulp slurry after flotation was concentrated to a concentration of 4% using an 80 mesh wire, 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 5°dH, and the hardness was Ca
Using Cl2, MgCl2, 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). The b value here refers to the b value in the Hunter color difference Lab color system, and its relationship with the tristimulus values XYZ is as shown below.

[0023]

[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 1 shows the average carbon number, iodine value, fatty acid composition, and content of fatty acids having 20 to 24 carbon atoms of component (a) used in various deinking agents. Further, Table 2 shows the component (b), and Table 3 shows the weight ratio of the component (a) and the component (b). The deinking performance is shown in Table 4.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

Example 2 This example is an example in which a deinking agent is added separately in the pulping process and the chemical mixing process. Municipally collected newspaper 2 x 5 cm
After shredding, put a certain amount of it into a tabletop disintegrator, and add 0.2% of water and caustic soda (based on raw materials) and 0.1% of the deinking agent (based on raw materials) shown in Tables 5 to 7. Pulp concentration 15%
After decomposition at 45°C for 12 minutes, aging treatment was performed at 55°C for 120 minutes. After that, it is dehydrated to 23% in a high-speed dehydrator, and the resulting mixture is 0.6% caustic soda (based on raw materials), 2.2% sodium silicate No. 3 (based on raw materials), and 30% hydrogen peroxide (based on raw materials).
．． 5% and 0.2% of the deinking agent (based on the raw materials) shown in Tables 5 to 7 were added, the pulp concentration was adjusted to 22% with water, and the mixture was mixed for 1 minute using a tabletop disintegrator. Thereafter, kneading treatment was performed using a two-screw lab kneader with a rotational speed of 300 rpm. after that,
Add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. After diluting the slurry to 1% with water, 30℃
A flotation treatment was performed for 10 minutes. Incidentally, 0.4% 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 5°dH, and the hardness was Ca
Using Cl2, MgCl2, 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 5 shows the average carbon number, iodine value, fatty acid composition, and content of fatty acids having 20 to 24 carbon atoms of component (a) used in various deinking agents. In addition, (b) components are shown in Table 6, (a)
Table 7 shows the weight ratios of the components and component (b). The deinking performance is shown in Table 8.

[0030]

[Table 5]

[0031]

[Table 6]

[0032]

[Table 7]

[0033]

[Table 8]

Example 3 This example is an example in which a deinking agent is added separately in the pulping process and the kneading process. After shredding municipally collected newspapers into 2 x 5 cm pieces, put a certain amount of them into a tabletop disintegrator, and add water, 0.2% caustic soda (based on the raw material), and the deinking agent shown in Tables 9 to 11 (based on the raw material). )0.3% was added, the pulp concentration was 15%, 4
After decomposition at 5°C for 12 minutes, aging treatment was performed at 55°C for 120 minutes. After that, it was dehydrated to 23% using a high-speed dehydrator.
Caustic soda (based on raw materials) 0.6%, Sodium silicate No. 3 (based on raw materials) 2.2%, 30% hydrogen peroxide (based on raw materials) 3.5%
%, and 0.2% of the deinking agent (based on the raw material) shown in Tables 9 to 11 was added, the pulp concentration was adjusted to 22% with water, and the pulp was mixed for 1 minute using a tabletop disintegrator. Thereafter, kneading treatment was performed using a two-screw lab kneader with a rotational speed of 300 rpm. after that,
Add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. After diluting the slurry to 1% with water, 30℃
A flotation treatment was performed 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 of CaCl2, MgCl2, and C
Adjustment was made so that a/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). Average carbon number, iodine value, fatty acid composition, and carbon number 20 to 24 of component (a) used in various deinking agents
Table 9 shows the fatty acid content of . In addition, the (b) component is shown in Table 10, and the weight ratio of the (a) component and (b) component is shown in Table 1.
Shown in 1. The deinking performance is shown in Table 12. Note that component (a) in Table 9 is No. No. 26 to 29 are cod, sardine, saury, and mackerel oil fatty acids, respectively. 30
is no. It is a 50/50 (weight ratio) blend of 26 and 27. Also, No. 31 to 33 are No. The iodine value (IV) of 26 was changed. Furthermore, No. 3
4 to 38 are stearic acid, myristic acid, and commercially available stearic acid (manufactured by Kao Corporation, trade name Lunac S-4), respectively.
0), a hardened beef tallow fatty acid, and a sardine oil fatty acid (iodine value (IV) = 175).

[0035]

[Table 9]

[0036]

[Table 10]

[0037]

[Table 11]

[0038]

[Table 12]

Example 4 This example is an example of adding a deinking agent in portions before the pulping process and the flotation process. After shredding municipally collected newspapers into 2 x 5 cm pieces, put a certain amount of them into a tabletop disintegrator, and add water, 0.2% caustic soda (based on the raw material), and the deinking agent shown in Tables 13 to 15 (based on the raw material). )0.2% was added 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% using a high-speed dehydrator, resulting in 0.6% caustic soda (based on raw materials) and 3% sodium silicate.
No. 2.2% (based on raw materials), 30% hydrogen peroxide (based on raw materials)
3.5% was added, the pulp concentration was adjusted to 22% with water, and the mixture was mixed for 1 minute using a tabletop disintegrator. After that, the rotation speed is 300r
Kneading treatment was performed using a PM twin-screw lab kneader. Then, add water to dilute to 4% and disintegrate again for 30 seconds using a tabletop disintegrator. Tables 13 to 15 are added to the pulp slurry.
After adding 0.3% of the deinking agent shown in (based on the raw material), 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 an image analysis device (×100
The number of unpeeled inks was measured using Table 13 shows the average carbon number, iodine value, fatty acid composition, and content of fatty acids having 20 to 24 carbon atoms of component (a) used in various deinking agents. In addition, (b) component is shown in Table 14, (a) component and (b)
) The weight ratios of the components are shown in Table 15. The deinking properties are shown in Table 16. In addition, all fatty acids of component (a) in Table 13 are sodium salts. Also, No. Nos. 39 to 42 are mixtures of fatty acid sodium salts so as to have a predetermined carbon number composition. Also, No. 43 is sodium stearate.

[0040]

[Table 13]

[0041]

[Table 14]

[0042]

[Table 15]

[0043]

[Table 16]

As exemplified above, a mixture of higher fatty acids having 8 to 24 carbon atoms or salts thereof, in which the average number of carbon atoms of the fatty acids in the mixture is in the range 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 (IV)
By using a deinking agent made by using a mixture in which is 45 or less and a compound represented by the general formula (1) in a specific ratio, deinked pulp with high whiteness, high b value, and less unpeeled ink can be produced. Obtainable.

Claims (2)

[Claims] Claim 1: (a) A higher fatty acid having 20 to 24 carbon atoms or a salt thereof containing a higher fatty acid having 8 to 24 carbon atoms or a salt thereof with an average carbon number of 12.7 to 22.5; A mixture having a content of 9.6 to 70.6% by weight and an iodine value (IV) of 45 or less, and (b) a compound R-O- represented by the following general formula (1)
(-AO-)l-H (1) [In the formula, R 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 a carbon number 2 to 4 alkylene oxides, when two or more types of alkylene oxides are present,
It may be a block polymer chain or a random polymer chain, and l is a number of 1 or more such that the overall molecular weight is 800 to 10,000. ] in weight ratio (a)/(b) = 90/10
A deinking agent characterized in that the deinking agent is contained in a ratio of ~40/60. 2. The deinking agent according to claim 1, wherein component (a) contains a fish oil fatty acid or a salt thereof as an essential component.