JP6951133B2 - Pitch suppressant for paper / pulp manufacturing process and pitch suppressing method for paper / pulp manufacturing process - Google Patents

Description

The present invention relates to a pitch suppressant for a paper / pulp manufacturing process and a pitch suppressing method for a paper / pulp manufacturing process.

In the production of paper and pulp, due to the diversification of raw materials and the speeding up of paper making speed, natural resins and fatty acids contained in raw wood, and synthetic adhesive substances such as adhesives and latex mixed from waste paper and waste paper Furthermore, pitch troubles due to pitch, which is a hydrophobic adhesive substance mainly composed of organic substances derived from additive chemicals such as sizing agents used in the paper manufacturing process, are increasing.

The pitch is usually dispersed in a colloidal form in the slurry of the papermaking process, but the colloidal state is changed due to some external action such as a strong shearing force, a sudden change in pH or water temperature, or an excessive addition of an aluminum sulfate band. It is thought to be destroyed and aggregated and coarsened.
Due to its adhesiveness, the agglomerated / coarsened pitch adheres to the manufacturing equipment such as fan pumps, flow pipes, chests, wires, felts, rolls, etc., causing stains on the equipment, and the deposits are large. After that, it peels off and reattaches to pulp and paper, which causes paper defects and paper breakage. Further, when it adheres to a wire, felt, or the like, the water squeezing decreases due to clogging, and the increase in the moisture content of the wet paper causes an increase in the drying load of the paper in the paper breakage or the drying process.
In this way, pitch is a causative substance that causes deterioration of paper product quality and productivity, and conventionally, it has been possible to prevent pitch aggregation during pulp or paper production and pitch adhesion to paper production equipment. A pitch inhibitor is used for the purpose of.

Pitch suppressants are roughly classified into internal pitch suppressants added to pulp slurries and external pitch suppressants that are brought into direct contact with the surface of manufacturing equipment such as wires, felts, and rolls by spraying with a shower or the like.
The internal pitch inhibitor treats the pitch contained in the total amount of pulp slurry, while the external pitch inhibitor sprays, sprays, immerses, etc. on the surface of any manufacturing equipment such as wire, felt, roll, etc. The pitch existing near the surface of the equipment is selectively processed.
For this reason, the external pitch inhibitor does not affect the quality of pulp slurries and paper products as compared with the internal pitch inhibitor, and the pitch to any equipment surface can be reduced with a smaller amount of chemicals used. There is an advantage that adhesion can be prevented.

Various methods have been conventionally proposed as pitch suppressing methods using an externally added pitch suppressing agent.
As a pitch inhibitor containing two components, a cationic polymer and a surfactant, as active ingredients, Japanese Patent Application Laid-Open No. 2-182995 (Patent Document 1) describes an epichlorohydrin-dimethylamine copolymer and a nonionic surfactant. A method of using a pitch inhibitor containing the above two components as active ingredients is disclosed.
As the pitch inhibitor used in the method of Patent Document 1, a cationic polymer that exhibits a pitch adhesion preventing action by hydrophilizing the pitch and the surface of the equipment is used. Furthermore, by using a nonionic surfactant in combination, the effect of preventing pitch adhesion can be further enhanced, and the accumulation of precipitates due to the cationic polymer itself on the surface of the equipment can be prevented.

Further, as a method for improving the pitch adhesion preventing effect, a method using a pitch inhibitor containing three components, which are a cationic polymer and a surfactant plus a phosphonic acid compound, as active ingredients has been proposed.
For example, Japanese Patent Application Laid-Open No. 2004-044067 (Patent Document 2) describes a cationic polymer (molecular weight 20,000-100,000) selected from polydiallyldimethylammonium salt or epichlorohydrin-dialkylamine copolymer. A paper / pulp manufacturing process containing 1-hydroxyethane-1,1-diphosphonic acid (HEDP) as an active ingredient and a nonionic surfactant obtained by adding ethylene oxide or ethylene oxide and propylene oxide to a higher aliphatic amine. A method of using a pitch inhibitor is disclosed.

However, problems caused by pitch have increased due to recent operational conditions such as closed water supply, increased utilization rate of used paper, complicated weaving structure of wire and felt, and increase in dehydration treatment amount due to the spread of shoe press papermaking. There is a tendency, and the effect of preventing pitch adhesion to the equipment surface is insufficient by the above method, and a more effective pitch inhibitor and pitch suppressing method are desired.

Japanese Unexamined Patent Publication No. 2-182995 Japanese Unexamined Patent Publication No. 2004-044067

In such a situation, the problem to be solved by the present invention is to obtain a pitch inhibitor and a pitch suppressing method having an excellent pitch adhesion preventing effect in the paper manufacturing process, particularly in the process of manufacturing paper from a raw material containing used paper pulp. To provide.

As a result of intensive research to solve the above problems, the present inventors have made three components of a specific cationic polymer having a specific mass average molecular weight, a nonionic surfactant, and a phosphonic acid compound as active components. We have found that the pitch inhibitor has an excellent effect of preventing pitch adhesion, and particularly exhibits an excellent effect on the pitch derived from used paper, and has completed the present invention.

That is, the present invention has the following configuration.
(1) A first aspect of the present invention is epichlorohydrin of less than 20,000 weight-average molecular weight of 10,000 or more - di methylamine copolymer or weight-average molecular weight of 10,000 or more than 25,000 diallyl dialkyl ammonium chloride - A pitch inhibitor for a paper / pulp manufacturing process containing a cationic polymer of an acrylamide copolymer, a nonionic surfactant, and a phosphonic acid compound as active ingredients.
(2) the second invention, in the first aspect, the diallyl dialkyl ammonium chloride - paper-acrylamide copolymer - acrylamide copolymer, diallyl dimethyl ammonium chloride is less than 10,000 to 20,000 It is a pitch inhibitor for the pulp manufacturing process.
(3) In the third invention, in any one of the first or second inventions, the nonionic surfactant is a polyoxyalkylene alkylamine, which is a pitch inhibitor for a paper / pulp manufacturing process.
(4) In the fourth invention, in any one of the first to third inventions, the phosphonic acid compound is 1-hydroxyethane-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, and 1,2, A pitch inhibitor for paper and pulp manufacturing processes, which is at least one selected from 4-tricarboxybutane-2-phosphonic acid.
(5) In the fifth invention, the pitch inhibitor for the paper / pulp manufacturing process of any one of the first to fourth inventions is added / diluted to the paper / pulp manufacturing process water and then brought into contact with the paper manufacturing apparatus. This is a method for suppressing the pitch in the paper / pulp manufacturing process.
(6) The sixth invention is the method for suppressing the pitch in the paper / pulp manufacturing process in which the raw material of the paper in the paper / pulp manufacturing process contains used paper pulp in the fifth invention.

By using the pitch inhibitor of the present invention, it is effective that stains such as pitch adhere to the surface of manufacturing equipment such as wires, felts and rolls in the paper manufacturing process, particularly in the process of manufacturing paper from raw materials containing used paper pulp. It is possible to improve the quality and productivity of paper products by suppressing the process troubles such as reduction of water tightness of wires and felts, paper defects and paper breakage.

The pitch-suppressing agent of the present invention and the pitch-suppressing method of a paper manufacturing facility using the same are made from an epichlorohydrin-dialkylamine copolymer and a diallyldialkylammonium chloride-acrylamide copolymer as a cationic polymer having a specific molecular weight. A pitch inhibitor for a paper / pulp manufacturing process containing at least one selected, a nonionic surfactant, and a phosphonic acid compound as active ingredients, and a pitch inhibitor added to the paper / pulp manufacturing process water for pitch This is a pitch suppression method that suppresses dirt.

（式中、Ｒ１、Ｒ２はアルキル基で、互いに同じでも異なってもよく、ｍは整数）で表される。
一般式（１）で表されるエピクロロヒドリン−ジアルキルアミン共重合体として、具
体的には、エピクロロヒドリン−ジメチルアミン共重合体およびエピクロロヒドリン−ジエチルアミン共重合体等が挙げられ、エピクロロヒドリン−ジメチルアミン共重合体が特に好ましい。エピクロロヒドリン−ジアルキルアミン共重合体の質量平均分子量は、ピッチ抑制効果の観点から、１０，０００以上２０，０００未満が好ましい。 The epichlorohydrin-dialkylamine copolymer used in the present invention having a mass average molecular weight of 10,000 or more and 25,000 or less is described in the general formula (1):

(In the formula, R1 and R2 are alkyl groups, which may be the same or different from each other, and m is an integer).
Specific examples of the epichlorohydrin-dialkylamine copolymer represented by the general formula (1) include an epichlorohydrin-dimethylamine copolymer and an epichlorohydrin-diethylamine copolymer. , Epichlorohydrin-dimethylamine copolymer is particularly preferred. The mass average molecular weight of the epichlorohydrin-dialkylamine copolymer is preferably 10,000 or more and less than 20,000 from the viewpoint of the pitch suppressing effect.

（式中、Ｒ１、Ｒ２はアルキル基で互いに同じでも異なってもよく、ｌ、ｍ、ｎは整数、ｌ≧ｌかつｍ≧１）で表される。
一般式（２）で表されるジアリルジアルキルアンモニウムクロライド−アクリルアミド共重合体として、具体的には、ジアリルジメチルアンモニウムクロライド−アクリルアミドおよびジアリルジエチルアンモニウムクロライド−アクリルアミド共重合体等が挙げられ、ジアリルジメチルアンモニウムクロライド−アクリルアミド共重合体が特に好ましい。ジアリルジアルキルアンモニウムクロライド−アクリルアミド共重合体の質量平均分子量は、ピッチ抑制効果の観点から１０，０００以上２０，０００未満が好ましい。 The diallyldialkylammonium chloride-acrylamide copolymer used in the present invention having a mass average molecular weight of 10,000 or more and 25,000 or less is described in the general formula (2):

(In the formula, R1 and R2 are alkyl groups and may be the same or different from each other, and l, m and n are integers, l ≧ l and m ≧ 1).
Specific examples of the diallyldialkylammonium chloride-acrylamide copolymer represented by the general formula (2) include diallyldimethylammonium chloride-acrylamide, diallyldiethylammonium chloride-acrylamide copolymer and the like, and diallyldimethylammonium chloride. -Acrylamide copolymers are particularly preferred. The mass average molecular weight of the diallyldialkylammonium chloride-acrylamide copolymer is preferably 10,000 or more and less than 20,000 from the viewpoint of the pitch suppressing effect.

Specific examples of the nonionic surfactant of the present invention include polyoxyalkylene alkyl ether, which is an alkylene oxide adduct to an aliphatic alcohol, polyoxyalkylene alkylphenyl ether, which is an adduct to alkylphenol, and sorbitan fatty acid ester. Polyoxyalkylene sorbitan fatty acid ester which is an addition to glycerin fatty acid ester, polyoxyalkylene glycerin fatty acid ester which is an addition to glycerin fatty acid ester, polyoxyalkylene pentaerythritol fatty acid ester which is an addition to pentaerythritol fatty acid ester, addition to fatty acid Examples thereof include polyoxyalkylene fatty acid esters which are substances, polyoxyalkylene fatty acid amides which are additives to fatty acid amides, and polyoxyalkylene alkyl amines which are additives to aliphatic amines. The aliphatic compound may be saturated or unsaturated.
Examples of the alkylene oxide to be added include ethylene oxide, propylene oxide, butylene oxide, and a mixture thereof. The alkylene oxide adduct containing two or more oxyalkylene groups contained in the molecule may be either a block copolymer or a random copolymer.
Among these, polyoxyalkylene alkylamine is preferable, and from the viewpoint of the effect of preventing pitch adhesion, propylene, which is a saturated or unsaturated aliphatic amine having 10 to 20 carbon atoms supplemented with 5 to 30 mol of ethylene oxide. It is preferably added with 0 to 15 mol of oxide.
Specific examples of saturated or unsaturated aliphatic amines having 10 to 20 carbon atoms include decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, and oleylamine. These nonionic surfactants can be used alone or in admixture of two or more.

The mass ratio of the cationic polymer to the nonionic surfactant in the pitch inhibitor of the present invention is preferably 25 to 500 parts by mass of the nonionic surfactant with respect to 100 parts by mass of the cationic polymer. More preferably, the amount of the nonionic surfactant is 100 to 300 parts by mass with respect to 100 parts by mass of the cationic polymer.

Specific examples of the phosphonic acid compound of the present invention include aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid, trimethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepenta (methylenephosphonic acid). ), 1-Hydroxyethane-1,1-diphosphonic acid (HEDP), 1-hydroxypropane-1,1-diphosphonic acid, 1-aminopropane-1,1-diphosphonic acid, and 1,2,4-tricarboxy Butane-2-phosphonic acid (PBTC) and the like can be mentioned.
Among these, 1-hydroxyethane-1,1-diphosphonic acid (HEDP), aminotrimethylenephosphonic acid (ATMP), 1,2,4-tricarboxybutane-2-phosphonic acid (PBTC), etc., and These alkali metal salts are preferred.
Examples of the alkali metal salt include sodium salt and potassium salt. These phosphonic acid compounds can be used alone or in admixture of two or more.
In the blending ratio of each component in the pitch inhibitor of the present invention, preferably 1 to 500 parts by mass, more preferably 5 to 50 parts by mass of the phosphonic acid compound with respect to 100 parts by mass of the total amount of the cationic polymer and the nonionic surfactant. It is a department.

The pitch inhibitor of the present invention includes, if necessary, surfactants, polymers, chelating agents, builders, organic acids, pH adjusters, solvents, defoamers, bactericides, preservatives, colorants, fragrances and the like. May be contained.
The pitch inhibitor of the present invention contains a drainage improver, a yield improver, a coagulant, a sizing agent, other pitch suppressors, a lubricant, a peelability improver, a cleaning agent, an acid, an alkali, and the like in the production of paper. It can also be used in combination with additives.

There is no limitation on the type of raw material pulp to which the pitch inhibitor of the present invention is applied, and bleached chemical pulp such as kraft pulp and sulfite pulp or unbleached chemical pulp, bleached mechanical pulp such as crushed wood pulp and thermomechanical pulp, or unbleached mechanical pulp. Examples thereof include bleached machine pulp, used newspaper pulp, used magazine paper, used cardboard pulp and waste paper such as deinked waste paper, and broken pulp such as machine waste paper and coated waste paper.
The effect of preventing pitch adhesion of the present invention is remarkable when used paper pulp is used, and the effect is particularly remarkable when a raw material containing 10% by mass or more of used paper pulp is used.
The pitch inhibitor of the present invention can be applied to the production of paper under acidic, neutral and alkaline conditions, and the type of paper produced is not limited. Examples of this paper include newspaper paper, printing paper such as high-quality paper and coated paper, information paper such as PPC paper and heat-sensitive paper base paper, wrapping paper such as pure white roll paper and bleached kraft paper, and sanitary paper such as tissue paper and toilet paper. Examples include mixed paper such as paper, food container base paper and coating printing base paper, cardboard base paper such as liner and medium shin base paper, paper container board such as white paperboard and colored paperboard, and miscellaneous paperboard such as gypsum board and paper tube base paper. Be done.

The pitch inhibitor of the present invention can prevent pitch adhesion in the paper manufacturing apparatus by making direct contact with the paper manufacturing apparatus. When contacting the paper manufacturing equipment, the pitch inhibitor is diluted with paper / pulp manufacturing process water such as roll or felt shower water or water added by a water doctor, and then sprayed, sprayed, or immersed in the paper manufacturing equipment. It is preferable to bring them into contact with each other. The amount of the pitch inhibitor added to the paper / pulp manufacturing process water depends on the amount of pitch present, but is usually 5 to 2,000 mg / L, preferably 10 to 500 mg / L in the water to be diluted. It is recommended to add so as to become.

Examples of the manufacturing equipment for contacting the pitch inhibitor of the present invention include wire, felt, center roll, table roll, breast roll, dandy roll, wire return roll, couture roll, press roll, suction roll, paper roll, backing roll, and the like. Examples include slice lips, forming boards, foils, doctors, suction boxes, yule boxes, and cambass. Among these, it is particularly effective for wires and felts mainly composed of hydrophobic resins such as polyester resin and nylon resin.

In the paper manufacturing process, in order to bring the pitch inhibitor of the present invention into contact with the manufacturing equipment, for example, it may be continuously or intermittently contacted before or during the operation of the manufacturing equipment, and during the operation of the manufacturing equipment. Is preferably in continuous contact with. Further, as described above, a method of contacting the shower water by spraying, spraying, dipping or the like is preferable, but by contacting the pitch inhibitor with the manufacturing equipment other than the target manufacturing equipment, it is indirect to the target manufacturing equipment. May be contacted.

The water to which the pitch inhibitor of the present invention is added includes any of groundwater such as well water, surface water such as river water or lake water, new water such as industrial water, recovered water, and recycled water such as wastewater treated water. Alternatively, these can be mixed and used.

The present invention will be described below with reference to Examples and Test Examples, but the present invention is not limited to these Examples and Test Examples.

［注］ＥＣＨ：エピクロロヒドリン
ＤＭＡ：ジメチルアミン
ＤＡＤＭＡＣ：ジアリルジメチルアンモニウムクロライド
ＡＡ：アクリルアミド
ｐＤＡＤＭＡＣ：ポリジアリルジメチルアンモニウムクロライド
ＰＯＡＳＡ：ポリオキシアルキレンステアリルアミン（エチレンオキサイド２０モル、プロピレンオキサイド２モルを付加したステアリルアミン）
ＨＥＤＰ：１−ヒドロキシエタン−１，１−ジホスホン酸 Table 1 shows the formulation of the pitch inhibitor used in Examples and Comparative Examples and the results of the pitch adhesion prevention test.

[Note] ECH: Epichlorohydrin DMA: Dimethylamine DADMAC: Dialyldimethylammonium chloride AA: Acrylamide pDADMAC: Polydiallyldimethylammonium chloride POASA: Stearyl with 20 mol of ethylene oxide and 2 mol of propylene oxide added. Amine)
HEDP: 1-hydroxyethane-1,1-diphosphonic acid

(Pitch adhesion prevention test)
(1) Actually used in a kraft paper making machine that uses only kraft pulp as a raw material (kraft paper machine felt) or a paperboard making machine that uses used paper as a raw material (waste paper pulp content of 90% or more). The pulp (paper machine felt) used in the above was extracted with a mixed solvent of ethanol: cyclohexane = 1: 2 (volume ratio). The obtained pitch component was dissolved again in ethanol: cyclohexane = 1: 2 (volume ratio) to prepare a 10% (w / v) pitch solution.
(2) In a 200 ml tall beaker, test water (150 ml) was prepared by diluting each pitch inhibitor of the above Examples and Comparative Examples with tap water so as to be 100 mg / L. A 60-mesh polyester net (20 mm × 60 mm × 0.28 mm, mesh size 0.273 mm, thread diameter 0.150 mm) was immersed in the test water and stirred at room temperature at 600 rpm.
(3) A 10% (w / v) pitch solution was added to the test water so as to be 100 mg / L, and the mixture was stirred at room temperature and 600 rpm for 2 hours.
(4) The polyester net was taken out, washed thoroughly with pure water, and then dissolved in 70% (v / v) ethanol so that Sudan Black B was 0.5% (w / v). The product was immersed in 50% (v / v) ethanol for 20 minutes, washed with pure water, and air-dried.
(5) Regarding the pitch adhesion surface of the polyester net dyed using the handy color meter NR-11A (manufactured by Nippon Denshoku Industries Co., Ltd.), the left half surface is 3 places (upper, middle, lower part) and the right half side is 3 places (upper part). , Middle part, lower part), and the color difference ΔE (ab) was measured at 6 points in total, and the average value was calculated.
(6) The average value of the color difference ΔE (ab) when the pitch inhibitor was not added was set as the pitch relative adhesion amount 10, and the pitch relative adhesion amount when each pitch inhibitor was added was calculated from the following equation.

Relative pitch adhesion amount when chemicals are added = Average value of ΔE (ab) when chemicals are added ÷ Average value of ΔE (ab) when no chemicals are added x 10

The evaluation shows that the larger the numerical value, the larger the relative pitch adhesion amount.

(Examples 1 to 6 and Comparative Examples 1 to 6)
Epichlorohydrin-dimethylamine (ECH / DMA) copolymer (mass average molecular weight 10,000, 15,000 or 19,000) is blended as a cationic polymer with respect to the pitch extracted from the kraft paper machine felt. The pitch inhibitor (Examples 1 to 3) and the pitch inhibitor (Examples 4 to 6) containing the DADMAC / AA copolymer are ECH / DMA copolymers (mass average molecular weight of 3,000 or 30,). 000) Higher pitch adhesion prevention effect than compounded products (Comparative Example 3, Comparative Example 4) and DADMAC / AA copolymer (mass average molecular weight 3,000 or 30,000) compounded products (Comparative Example 5, Comparative Example 6) The effect was equivalent to that of the pDADMAC (mass average molecular weight 19,000 or 30,000) compounded product (Comparative Example 1 and Comparative Example 2).
On the other hand, for the pitch extracted from the paperboard machine felt, the pitch inhibitors of Examples 1 to 6 are pDADMAC (mass average molecular weight 19,000 or 30,000) compounded products (Comparative Example 1, Comparative Example 2). ECH / DMA copolymer (mass average molecular weight 3,000 or 30,000) compounded product (Comparative Example 3, Comparative Example 4), DADMAC / AA copolymer (mass average molecular weight 3,000 or 30,000) compounded product It showed a higher pitch adhesion prevention effect than (Comparative Example 5 and Comparative Example 6).

(Example 7, Example 8 and Comparative Examples 7 to 9)
The pitch inhibitor (Example 7) having a reduced content of the nonionic surfactant as compared with Example 1 had a reduced pitch adhesion preventing effect as compared with Example 1 regardless of the type of pitch. The pitch inhibitor (Example 8) having a reduced content of the nonionic surfactant as compared with Example 4 had a reduced effect of preventing pitch adhesion as compared with Example 4 regardless of the type of pitch. For pitches extracted from kraft paper machine felt, Examples 7 and 8 are ECH / DMA copolymers (mass average molecular weight 30,000) formulations (Comparative Example 8) and DADMAC / AA copolymers. It showed a higher pitch adhesion prevention effect than the (mass average molecular weight 30,000) compounded product (Comparative Example 9), and showed the same effect as the pDADMAC (mass average molecular weight 30,000) compounded product (Comparative Example 7).
However, for the pitch extracted from the paperboard machine felt, the pitch inhibitors of Examples 7 and 8 are pDADMAC (mass average molecular weight 30,000) compounded product (Comparative Example 7), ECH / DMA copolymer. It showed a higher pitch adhesion prevention effect than the compounded product (mass average molecular weight 30,000) (Comparative Example 8) and the DADMAC / AA copolymer (mass average molecular weight 30,000) compounded product (Comparative Example 9).

(Example 9, Example 10 and Comparative Examples 10-12)
The pitch inhibitor (Example 9) having an increased content of the nonionic surfactant as compared with Example 1 had an improved effect of preventing pitch adhesion as compared with Example 1 regardless of the type of pitch. The pitch inhibitor (Example 10) having an increased content of the nonionic surfactant as compared with Example 4 had an improved effect of preventing pitch adhesion as compared with Example 4, regardless of the type of pitch. For pitches extracted from kraft paper machine felt, Examples 9 and 10 are ECH / DMA copolymer (mass average molecular weight 30,000) formulations (Comparative Example 11) and DADMAC / AA copolymers. It showed a higher pitch adhesion prevention effect than the (mass average molecular weight 30,000) compounded product (Comparative Example 12), and showed the same effect as the pDADMAC (mass average molecular weight 30,000) compounded product (Comparative Example 10).
However, for the pitch extracted from the paperboard machine felt, the pitch inhibitors of Examples 9 and 10 are pDADMAC (mass average molecular weight 30,000) compounded products (Comparative Example 10), ECH / DMA copolymers. It showed a higher pitch adhesion prevention effect than the compounded product (mass average molecular weight 30,000) (Comparative Example 11) and the DADMAC / AA copolymer (mass average molecular weight 30,000) compounded product (Comparative Example 12).

(Example 11, Example 12 and Comparative Examples 13 to 15)
The pitch inhibitor (Example 11) having a reduced HEDP content as compared with Example 1 had a reduced pitch adhesion preventing effect as compared with Example 1 regardless of the type of pitch. The pitch inhibitor (Example 12) having a reduced HEDP content as compared with Example 4 had a reduced pitch adhesion preventing effect as compared with Example 4, regardless of the type of pitch. For pitches extracted from kraft paper machine felt, Examples 11 and 12 are ECH / DMA copolymer (mass average molecular weight 30,000) formulations (Comparative Example 14) and DADMAC / AA copolymers. It showed a higher pitch adhesion prevention effect than the (mass average molecular weight 30,000) compounded product (Comparative Example 15), and showed the same effect as the pDADMAC (mass average molecular weight 30,000) compounded product (Comparative Example 13).
However, for the pitch extracted from the paperboard machine felt, the pitch inhibitors of Examples 11 and 12 are pDADMAC (mass average molecular weight 30,000) compounded products (Comparative Example 13), ECH / DMA copolymers. It showed a higher pitch adhesion preventing effect than the compounded product (mass average molecular weight 30,000) (Comparative Example 14) and the DADMAC / AA copolymer (mass average molecular weight 30,000) compounded product (Comparative Example 15).

(Example 13, Example 14 and Comparative Examples 16-18)
The pitch inhibitor (Example 13) having a higher HEDP content than in Example 1 had an improved pitch adhesion preventing effect as compared with Example 1 regardless of the type of pitch. The pitch inhibitor (Example 14) having a higher HEDP content than in Example 4 had an improved pitch adhesion preventing effect as compared with Example 4, regardless of the type of pitch. For pitches extracted from kraft paper machine felt, Examples 13 and 14 are ECH / DMA copolymer (mass average molecular weight 30,000) formulations (Comparative Example 17) and DADMAC / AA copolymers. It showed a higher pitch adhesion prevention effect than the (mass average molecular weight 30,000) compounded product (Comparative Example 18), and showed the same effect as the pDADMAC (mass average molecular weight 30,000) compounded product (Comparative Example 16).
However, for the pitch extracted from the paperboard machine felt, the pitch inhibitors of Examples 13 and 14 are pDADMAC (mass average molecular weight 30,000) compounded products (Comparative Example 16), ECH / DMA copolymers. It showed a higher pitch adhesion prevention effect than the compounded product (mass average molecular weight 30,000) (Comparative Example 17) and the DADMAC / AA copolymer (mass average molecular weight 30,000) compounded product (Comparative Example 18).

In the composition of the pitch suppressants of Examples 1 to 6 and Comparative Examples 1 to 6, pitch suppressants using ATMP or PBTC instead of HEDP as the phosphonic acid compound were prepared, and kraft paper machine felt and paperboard machine. A pitch adhesion prevention test was performed on the pitch extracted from the felt.
As a result, even in the pitch inhibitor containing ATMP or PBTC, the same pitch adhesion preventing effect as the pitch inhibitor containing HEDP (Examples 1 to 6 and Comparative Examples 1 to 6) was obtained.

A pitch inhibitor containing an ECH / DMA copolymer or DADMAC / AA copolymer having a mass average molecular weight of 10,000 to 19,000 as a cationic polymer has a mass average molecular weight of 19,000 or 30,000. It is not always clear why the pitch adhesion can be suppressed more than the pitch inhibitor containing any of pDADMAC, an ECH / DMA copolymer having a mass average molecular weight of 30,000, and a DADMAC / AA copolymer.
However, while pDADMAC has only a cationic charge in the polymer, the ECH / DMA copolymer and the DADMAC / AA copolymer have hydrogen bonds such as hydroxyl groups and amide groups in the polymer in addition to the cationic charge. It is more hydrophilic than pDADMAC. Further, since the molecular weight of the polymer is small, the dispersibility of the polymer in water is good, and it is easy to come into contact with a hydrophobic surface such as a fine pitch, a wire, or felt.
From these facts, the ECH / DMA copolymer and the DADMAC / AA copolymer having a mass average molecular weight of 10,000 to 19,000 have a mass average molecular weight of 19,000 or 30,000 pDADMAC and a mass average molecular weight of 30,000. Compared with the ECH / DMA copolymer or DADMAC / AA copolymer, the effect of hydrophilizing the fine pitch and dispersing it in water is high, and the effect of hydrophilizing the hydrophobic surface of wire, felt, etc. is also high. , It is considered that it shows a more excellent effect of suppressing pitch adhesion.
When the mass average molecular weight is as small as 3,000, the hydrophilicity of the polymer becomes too high and it becomes difficult to contact the hydrophobic surface such as fine pitch, wire, felt, etc., so it is presumed that the effect of suppressing pitch adhesion is reduced. Will be done.

Furthermore, in order to evaluate the performance of the pitch suppressant in the actual machine, in the paper manufacturing process of the actual machine, a pitch suppressant composed of three components of a cationic polymer, a nonionic surfactant, and a phosphonic acid compound is used in the manufacturing process of shower water or the like. As a result of adding or diluting with water, poor discharge of shower water due to clogging of the shower line nozzle for cleaning (when the pitch inhibitor stock solution is press-fitted into the shower pipe with a chemical injection pump), due to blockage of the chemical injection pump discharge port Poor discharge of diluted solution (when the pitch suppressant diluted solution is press-fitted into the shower pipe with a chemical injection pump), poor water squeezing due to clogging of wires or felt, and new obstacles such as paper breakage may occur. It turned out to be.
As a result of investigating the cause by the present inventors, when these three components are added or diluted in manufacturing process water such as shower water, the components of the pitch inhibitor react with iron and the like in the diluted water, and precipitates are generated. Was the cause of the failure.

In the tabletop test, the pitch inhibitor used in Examples 1 to 14 and Comparative Examples 1 to 18 was added to the water in the paper manufacturing process so as to be 1,000 mg / L, and the iron content was made of cold-rolled steel sheet (SPCC). As a result of immersing the test piece and visually evaluating the amount of precipitates generated, no precipitates were observed in the examples, but some precipitates were observed in the comparative examples.
As a result of analyzing the precipitate, the precipitate was derived from a pitch inhibitor composed of a cationic polymer, a phosphonic acid compound and iron.
From this, it was confirmed that the pitch inhibitor of the present invention not only has an excellent effect of preventing pitch adhesion, but also can effectively suppress the generation of precipitates derived from the pitch inhibitor.

Claims (6)

Weight average molecular weight is less than 10,000 20,000 epichlorohydrin - di methylamine copolymer or weight-average molecular weight of 10,000 or more than 25,000 diallyl dialkyl ammonium chloride - cationic polymers of acrylamide copolymer , A nonionic surfactant, and a pitch inhibitor for a paper / pulp manufacturing process, which comprises a phosphonic acid compound as an active ingredient. The diallyl dialkyl ammonium chloride - acrylamide copolymers, the weight average molecular weight, diallyl dimethyl ammonium chloride is less than 10,000 to 20,000 - for paper pulp manufacturing process according to claim 1 acrylamide copolymer Pitch inhibitor. The pitch inhibitor for a paper / pulp manufacturing process according to claim 1 or 2, wherein the nonionic surfactant is a polyoxyalkylene alkylamine. Claim 1 in which the phosphonic acid compound is at least one selected from 1-hydroxyethane-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, and 1,2,4-tricarboxybutane-2-phosphonic acid. The pitch inhibitor for the paper / pulp manufacturing process according to any one of claims 3. The paper / pulp manufacturing process pitch inhibitor according to any one of claims 1 to 4 is added / diluted to paper / pulp manufacturing process water and then brought into contact with the paper manufacturing apparatus. A method for suppressing the pitch in the paper / pulp manufacturing process. The method for suppressing pitch in a paper / pulp manufacturing process according to claim 5, wherein the used paper pulp is contained in the raw material of the paper in the paper / pulp manufacturing process.