JP2020147888A - Dispersion for paper manufacturing agent, paper strengthening agent including the dispersion for paper manufacturing agent, freeness improver, and yield improver - Google Patents

Abstract

To provide a dispersion for a paper manufacturing agent which does not generate an aggregate on polymerization and show excellent paper-strengthening effect, freeness effect, and yield effect.SOLUTION: The invention provides a dispersion for a paper manufacturing agent including a (meth)acrylamide polymer (A), wherein the dispersion for paper manufacturing agent is characterized by that the dispersion includes at least two kinds of an inorganic salt (B), the component (B) includes at least two kinds selected from a group comprising an inorganic ammonium salt, an inorganic sodium salt and an inorganic potassium salt, the dispersion shows an elongation viscosity of 40-200 mm when converted to a solution having a solid content concentration of the component (A) of 0.5 wt.%, and the dispersion shows an intrinsic viscosity (temperature 25°C) of 10-30 dl/g when converted to a liquid diluted with 1-N NaCl solution.SELECTED DRAWING: None

Description

The present invention relates to a dispersion for paper chemicals, a paper strength enhancer containing the dispersion for paper chemicals, a drainage improver, and a yield improver.

In the paper making process, various paper-making chemicals are added to the raw material pulp according to the required performance and application. For example, when increasing the strength of paper, a paper strength enhancer and a drainage effect are added. A drainage improver is used to increase the yield, and a yield improver is used to enhance the yield effect of pulp fine fibers, paper chemicals, ash, etc. in the paper.

There are various forms of such paper-making chemicals. For example, as a chemical having a paper strength enhancing, drainage and retention effect, a dispersion obtained by dispersing and polymerizing a monomer component mainly composed of acrylamide in a salt aqueous solution can be mentioned (Patent Document 1). As such a dispersion for paper-making chemicals, one having a high intrinsic viscosity is suitable in order to enhance the effect of improving the yield of pulp fine fibers, internal chemicals for paper-making, ash, etc. in the paper.

As a dispersion liquid for papermaking chemicals having a high intrinsic viscosity, for example, a soluble polymer dispersant is allowed to coexist in a salt aqueous solution, and a specific amount of a polymerization retardant substance is added together with a vinyl monomer or a vinyl monomer mixture. A dispersion liquid containing a high molecular weight water-soluble polymer having an intrinsic viscosity in the range of 18 to 25 dl / g under specific conditions obtained by dispersion polymerization with addition and stirring is disclosed (Patent Document 2). .. However, in the dispersion liquid, the generated particles may be united to cause dispersion failure, resulting in the formation of agglomerates, or the paper strength effect, the drainage effect and the yield effect may be inferior.

Japanese Unexamined Patent Publication No. 2003-73566 Japanese Unexamined Patent Publication No. 2008-56752

An object of the present invention is to provide a dispersion for paper chemicals, which is excellent in paper strength effect, drainage effect and yield effect without generating agglomerates during polymerization.

As a result of diligent studies, the present inventors have found that the above problems can be solved by using a plurality of specific salts in combination and by causing the dispersion liquid for paper chemicals to exhibit a predetermined elongation viscosity, and complete the present invention. It came to. That is, the present invention relates to the following dispersions for paper chemicals, paper strength enhancers containing the dispersions for paper chemicals, drainage improvers, and yield improvers.

1. 1. A dispersion for paper chemicals containing the (meth) acrylamide polymer (A).
The dispersion contains two or more salts (B) selected from the group consisting of ammonium salt, sodium salt and potassium salt.
The extensional viscosity of the dispersion liquid when the solid content concentration of the component (A) was made into a 0.5% by weight aqueous solution was 40 to 200 mm.
A dispersion for paper chemicals, which has an intrinsic viscosity (temperature 25 ° C.) of 10 to 30 dl / g obtained by diluting the dispersion with a 1N NaCl aqueous solution.

2. 2. The dispersion liquid for paper chemicals according to item 1 above, wherein the component (A) contains a polymer of a monomer component containing (meth) acrylamide (a1) and a cationic unsaturated monomer (a2).

3. 3. The dispersion for paper chemicals according to item 2 above, wherein the component (a2) is a tertiary amino group-containing (meth) acrylate and / or a quaternized salt of the (meth) acrylate.

4. The dispersion liquid for paper chemicals according to item 2 or 3 above, wherein the monomer component further contains an anionic unsaturated monomer (a3).

5. The dispersion liquid for paper chemicals according to item 4 above, wherein the component (a3) is at least one selected from the group consisting of acrylic acid, itaconic acid and itaconic anhydride.

6. The dispersion for paper chemicals according to any one of items 1 to 5 above, wherein the component (B) contains ammonium sulfate and sodium sulfate and / or sodium chloride.

7. The dispersion liquid for paper chemicals according to any one of the above items 1 to 6, wherein the content of the component (B) is 15 to 45% by weight with respect to 100% by weight of the dispersion liquid for paper chemicals.

8. The dispersion liquid for paper chemicals according to any one of the above items 1 to 7, further comprising a polymer dispersant (C) and / or a polyhydric alcohol (D).

9. A paper strength enhancer containing the dispersion liquid for paper chemicals according to any one of the above items 1 to 8.

10. A drainage improver containing the dispersion liquid for paper chemicals according to any one of the above items 1 to 8.

11. A yield improver containing the dispersion for paper chemicals according to any one of the above items 1 to 8.

According to the dispersion liquid for paper chemicals of the present invention, since the liquid contains two kinds of specific salts, the particles generated during polymerization are well dispersed without coalescence and no agglomerates are generated. Further, the dispersion liquid for paper manufacturing chemicals exhibited excellent paper strength effect, drainage effect and yield effect by adjusting so as to have a specific extensional viscosity in addition to the intrinsic viscosity.

The dispersion liquid for paper chemicals of the present invention contains a (meth) acrylamide-based polymer (A) (hereinafter, referred to as a component (A)), and the dispersion liquid is a specific two or more kinds of salts (referred to as a component (A)). B) (hereinafter referred to as component (B)) is included.

<About (A) component>
The component (A) is not particularly limited as long as it is a (meth) acrylamide-based polymer, but from the viewpoint of enhancing the self-adsorption property of the component (A) to pulp, (meth) acrylamide (a1) (hereinafter, (a1) ) Component) and a polymer of a monomer component containing a cationic unsaturated monomer (a2) (hereinafter referred to as (a2) component) are preferable. The (meth) acrylic means methacrylic or acrylic, and the "unsaturated monomer" means one having one or more double bonds or triple bonds in one molecule of the monomer (the same applies hereinafter). ).

Examples of the component (a1) include acrylamide and methacrylamide.

The content of the component (a1) is not particularly limited, and is usually about 10 to 99 mol%, preferably about 15 to 95 mol%, more preferably about 10 to 99 mol%, with the total of all monomer components being 100 mol% in terms of molar ratio. Is 50-90 mol%.

The component (a2) is not particularly limited, and various known components can be used. For example, a secondary amino group-containing unsaturated monomer, a tertiary amino group-containing unsaturated monomer, and 4 of these unsaturated monomers. Examples include graded salts.

The secondary amino group-containing unsaturated monomer is not particularly limited, and examples thereof include diallylamine. The tertiary amino group-containing unsaturated monomer is not particularly limited, and for example, a tertiary amino group-containing (meth) such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate. Acrylate; Examples thereof include tertiary amino group-containing (meth) acrylamide such as N, N-dimethylaminopropyl (meth) acrylamide and N, N-diethylaminopropyl (meth) acrylamide. The quaternized salt of these monomers means a quaternized salt obtained by reacting the secondary amino group-containing unsaturated monomer or the tertiary amino group-containing unsaturated monomer with a quaternizing agent, and the like. The salt may be an inorganic acid salt such as a hydrochloride or a sulfate, or an organic acid salt such as an acetate. Examples of the quaternary agent include methyl chloride, benzyl chloride, dimethyl sulfate, epichlorohydrin and the like. These may be used alone or in combination of two or more. Among them, the tertiary amino group is easily dispersed in an aqueous solution containing the component (B) because the component (A) to be produced has a high extensional viscosity and an appropriate hydrophobicity, so that it can be easily granulated. It preferably contains a (meth) acrylate and / or a quaternized salt of the (meth) acrylate, with the methyl chloride salt of N, N-dimethylaminoethyl acrylate and the benzyl chloride salt of N, N-dimethylaminoethyl acrylate. More preferred. In addition, (meth) acrylate means methacrylate or acrylate (the same applies hereinafter).

The content of the component (a2) is not particularly limited, and from the viewpoint that a higher molecular weight component (A) can be obtained and an excellent paper strength effect, drainage effect and yield effect are exhibited, all the monomers in a molar ratio. Assuming that the total of the components is 100 mol%, it is usually about 1 to 45 mol%, preferably about 5 to 40 mol%, and more preferably about 10 to 30 mol%.

It is preferable that the monomer component further contains an anionic unsaturated monomer (a3) (hereinafter, referred to as a component (a3)). By including the component (a3), the produced component (A) can be easily dispersed in the aqueous solution containing the component (B).

The component (a3) is not particularly limited, and various known components can be used. For example, α, β-unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; maleic anhydride and fumaric acid. , Α, β-unsaturated dicarboxylic acids such as itaconic acid, muconic acid, citraconic acid; unsaturated carboxylic acid anhydrides such as anhydrous (meth) acrylic acid, maleic anhydride, itaconic anhydride; vinyl sulfonic acid, styrene sulfonic acid Organic sulfonic acids such as; sodium salts, potassium salts and the like of these acids can be mentioned. These may be used alone or in combination of two or more. Among them, α, β-unsaturated monocarboxylic acid and α, β-unsaturated dicarboxylic acid are obtained from the viewpoint that a higher molecular weight component (A) can be obtained and an excellent paper strength effect, drainage effect and yield effect are exhibited. , Unsaturated carboxylic acid anhydride is preferable, and at least one selected from the group consisting of acrylic acid, itaconic acid and itaconic anhydride is more preferable.

The content of the component (a3) is not particularly limited, and from the viewpoint that a higher molecular weight component (A) can be obtained and an excellent paper strength effect, drainage effect and yield effect are exhibited, all the monomers in a molar ratio. Assuming that the total of the components is 100 mol%, it is usually 40 mol% or less, preferably 30 mol% or less, and more preferably 25 mol% or less.

Further, the monomer component may contain an unsaturated monomer (a4) (hereinafter, referred to as a component (a4)) other than the components (a1) to (a3).

The component (a4) is not particularly limited, and various known components can be used. Examples of the component (a4) include N-alkyl (meth) acrylamides such as N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, and N-isopropyl (meth) acrylamide; N, N-dimethyl (meth). N, N-dialkyl (meth) acrylamide such as acrylamide, N, N-diethyl (meth) acrylamide; N, N such as N, N'-methylenebis (meth) acrylamide, N, N'-ethylenebis (meth) acrylamide, etc. '-Alkylene bis (meth) acrylamide; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate Alkyl (meth) acrylates such as diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxy. Polyethylene glycol mono (meth) acrylate, polytrimethylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate, polyethylene glycol propylene glycol mono (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di ( (Meta) acrylates having a polyalkylene glycol group such as meta) acrylate; allyl (meth) acrylate, triallyl trimellitate, triallyl isocyanurate, triallylamine, tetraallyl pyromerylate, N-allyl (meth) acrylamide, Unsaturated monomers having an allyl group such as N, N-diallyl (meth) acrylamide; aromatic unsaturated monomers such as divinylbenzene, styrene, α-methylstyrene and vinyltoluene; monovinyl esters such as vinylacetate and vinylpropionate. Divinyl esters such as divinyl adipate and divinyl sebacate; 1,3,5-tri (meth) acryloyl-1,3,5-triazine, 1,3,5-tri (meth) acryloylhexahydro-1,3, Triazine having a (meth) acryloyl group such as 5-triazine; diacetone (meth) acrylamide, N-methylol (meth) acrylamide, 2-a Examples thereof include krillamide-2-methylpropanesulfonic acid.

The amount of the component (a4) used is not particularly limited, but is preferably 5 mol% or less in terms of molar ratio, with the total of all monomer components being 100 mol%.

Furthermore, other components that do not belong to the monomer component may be used. Examples of the other components include mercaptans such as 2-mercaptoethanol and n-dodecyl mercaptan; methallyl sulfonates such as sodium methallyl sulfonate, potassium metharyl sulfonate, ammonium metharyl sulfonate; ethanol, Aliper alcohols such as isopropyl alcohol and pentyl alcohol; chain transfer agents such as α-methylstyrene dimer, carbon tetrachloride, ethylbenzene, isopropylbenzene, cumene, 2,4-diphenyl-4-methyl-1-pentene; citrate, Organic acids such as succinic acid and oxalic acid; inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid; inorganic bases such as sodium hydroxide, potassium hydroxide and calcium hydroxide; antifoaming agents, antioxidants, preservatives, etc. Be done. These may be used alone or in combination of two or more. The content thereof is not particularly limited, but is preferably 5% by weight or less in 100% by weight of the dispersion liquid for paper manufacturing chemicals containing a solvent such as water.

The component (B) is two or more salts selected from the group consisting of ammonium salt, sodium salt and potassium salt. By containing two or more kinds of salts, the salting out effect is strengthened, so that the produced component (A) is not united and is atomized and easily dispersed in the aqueous solution containing the component (B).

The content of the component (B) is not particularly limited, but the particles of the component (A) are obtained without coalescence and gelation, and exhibit excellent paper strength effect, drainage effect and yield effect. , 15 to 45% by weight is preferable, 15 to 40% by weight is more preferable, and 15 to 35% by weight is particularly preferable with respect to 100% by weight of the dispersion liquid for paper chemicals.

The ammonium salt is not particularly limited, and is, for example, an organic ammonium salt such as ammonium acetate, ammonium propionate, ammonium oxalate, ammonium citrate, ammonium succinate, tetramethylammonium chloride; ammonium chloride, ammonium bromide, iodine. Examples thereof include inorganic ammonium salts such as ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium phosphate, ammonium hydrogen phosphate, ammonium hydrogencarbonate and ammonium carbonate. These may be used alone or in combination of two or more.

The sodium salt is not particularly limited, and is, for example, an organic sodium salt such as sodium acetate, sodium propionate, sodium oxalate, sodium citrate, sodium succinate; sodium chloride, sodium bromide, sodium iodide, sodium nitrate, etc. Examples thereof include inorganic sodium salts such as sodium sulfate, sodium phosphate, sodium hydrogen phosphate, sodium hydrogen carbonate, and sodium carbonate. These may be used alone or in combination of two or more.

The potassium salt is not particularly limited, and is, for example, an organic potassium salt such as potassium acetate, potassium propionate, potassium oxalate, potassium citrate, potassium succinate; potassium chloride, potassium bromide, potassium iodide, potassium nitrate, sulfuric acid. Examples thereof include inorganic potassium salts such as potassium, potassium phosphate, potassium hydrogen phosphate, potassium hydrogen carbonate, and potassium carbonate. These may be used alone or in combination of two or more.

Among them, an inorganic ammonium salt and an inorganic sodium salt are preferable, and ammonium sulfate and sodium sulfate and / or sodium chloride are more preferable, from the viewpoint that the particle (A) component produced during the polymerization is promoted and dispersed well. ..

The contents of the inorganic ammonium salt and the inorganic sodium salt are not particularly limited, but the solid content is obtained from the viewpoint that a higher molecular weight component (A) can be obtained and an excellent paper strength effect, drainage effect and yield effect are exhibited. In terms of weight ratio, (inorganic ammonium salt) / (inorganic sodium salt) = about 99/1 to 10/90 is preferable, 97/3 to 25/75 is more preferable, and 95/5 to 40/60 is particularly preferable.

The dispersion liquid for paper chemicals of the present invention can be obtained by various known production methods, but a higher molecular weight component (A) can be obtained, and it exhibits excellent paper strength effect, drainage effect and yield effect. Therefore, in a salt aqueous solution having a saturation concentration of the component (B) or less (hereinafter, also simply referred to as “salt aqueous solution”), the components (a1) and (a2), and if necessary, the components (a3) and (a4). A method of dispersing and polymerizing the component (a5) in the presence of a polymerization initiator is preferable. The monomer component may be added dropwise, and one or more salts may be added during or after the polymerization. Further, the polymerization initiator may be added all at once or separately.

The conditions for the dispersion polymerization are not particularly limited, but for example, the temperature is preferably about 15 to 70 ° C, more preferably about 30 to 60 ° C. The time is preferably about 3 to 30 hours, more preferably about 6 to 18 hours.

The concentration of the aqueous salt solution is not more than the saturated concentration. As a result, the component (A) produced by dispersion polymerization can be precipitated as particles to produce a dispersion liquid for paper chemicals. From the same point of view, a saturation concentration of 15% by weight or more is preferable.

The polymerization initiator is not particularly limited, and is, for example, persulfate such as ammonium persulfate, potassium persulfate, calcium persulfate; 2,2'-azobis (2-amidinopropane) hydrochloride, 2,2'-azobis. [2- (2-Imidazoline-2-yl) propane] azo-based polymerization initiators such as hydrochloride can be mentioned. Among these, 2,2'-azobis (2-amidinopropane) hydrochloride and 2,2'-azobis [2- (2-imidazolin-2) are preferable from the viewpoint of making the cross-linking reaction less likely to occur during dispersion polymerization. -Il) Propane] Hydrochloride.

The amount of the polymerization initiator used is not particularly limited, and is usually about 0.02 to 0.3 parts by weight, preferably 0.04 to 0.2 parts by weight, based on 100 parts by weight of all the monomer components (solid content). It is about the weight part.

Further, in the dispersion polymerization, the polymer dispersant (C) (hereinafter referred to as the component (C)) and / or the polymer dispersant (C) and / or from the viewpoint that the generated particles of the component (A) are well dispersed in the aqueous solution containing the component (B). It is preferable to include a polyhydric alcohol (D) (hereinafter, referred to as a component (D)).

The component (C) is not particularly limited as long as it is a polymer dispersant, and for example, 30 to 99.99 mol% of the cationic radically polymerizable monomer (c1) (hereinafter, also referred to as the component (c1)), and Examples thereof include a copolymer of a reactant containing 0.01 to 1 mol% of a sulfonic acid group-containing monomer and / or a salt thereof (c2) (hereinafter, also referred to as a component (c2)). By using the component (C), the component (A) can be easily dispersed in the aqueous solution.

The component (c1) is not particularly limited, and for example, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, N. , N-diethylaminopropyl (meth) acrylamide and other tertiary amino group-containing unsaturated monomers; obtained by reacting a salt of a tertiary amino group-containing unsaturated monomer with a tertiary amino group-containing unsaturated monomer and a quaternary agent. Examples thereof include quaternary products. The salt may be an inorganic acid salt such as hydrochloride or sulfate, or an organic acid salt such as acetate. Examples of the quaternary agent include methyl chloride, benzyl chloride, dimethyl sulfate, epichlorohydrin and the like. These may be used alone or in combination of two or more. Among them, 4 of N, N-dimethylaminoethyl acrylate and N, N-dimethylaminoethyl methacrylate, which are quaternized products of N, N-dimethylaminoethyl acrylate, from the viewpoint that the component (A) disperses well while maintaining the solubility in the aqueous solution containing the component (B). Classified products are preferred.

The component (c2) is not particularly limited as long as it is a monomer having at least one sulfonic acid group and / or a salt thereof having one unsaturated double bond. For example, unsaturated monomers having (meth) allyl groups and sulfonic acid groups such as allyl sulfonic acid, calcium allyl sulfonate, methallyl sulfonic acid, calcium metharyl sulfonate, ammonium metharyl sulfonate, or salts thereof; vinyl sulfonic acid. , Styrene sulfonic acid, 2-acrylamide-2-methylpropan sulfonic acid and the like. These may be used alone or in combination of two or more. Among them, an unsaturated monomer having a (meth) allyl group and a sulfonic acid group or a salt thereof is preferable, and (meth) is preferable because radical transfer (chain transfer) is likely to occur and the molecular weight and crosslinked structure can be easily adjusted. Sodium allylsulfonate is more preferred.

Further, the reaction product of the component (C) is an unsaturated monomer other than the components (c1) to (c2), if necessary, as long as the components (c1) and (c2) are contained within the above range of the amount used. c3) (hereinafter, also referred to as (c3) component) may be contained. The component (c3) is not particularly limited, and for example, N, N-dialkyl (meth) such as N, N-dimethylacrylamide, N, N-diethyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide and the like. Acrylamide; N-alkyl (meth) acrylamide such as N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-t-butyl (meth) acrylamide; N, N'- N, N'-alkylene bis (meth) acrylamide such as methylenebis (meth) acrylamide, N, N'-ethylenebis (meth) acrylamide; 1,3,5-triacrylloylhexahydro-1,3,5-triazine, etc. Triazine having a (meth) acryloyl group; aromatic unsaturated monomers such as styrene, α-methylstyrene, vinyltoluene; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) ) Alkyl (meth) acrylates such as acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate; vinyl acetate, vinyl. Vinyl esters such as propionate; unsaturated carboxylic acids such as (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride; acrylamide, methacrylamide, etc. Can be mentioned. These may be used alone or in combination of two or more. Of these, acrylamide, N, N-dimethylacrylamide, and N, N-methylenebisacrylamide are preferable from the viewpoint of high copolymerizability with the components (c1) and (c2). The amount of the component (c3) used is less than 50 mol%, where the total amount of the components (c1) to (c3) is 100 mol%.

The amount of the component (C) used is not particularly limited, but 1 to 15 weight by weight with respect to 100 parts by weight of the component (A) from the viewpoint of assisting the dispersion of the particles of the component (A) to be produced and increasing the molecular weight. About 1 to 13 parts by weight is more preferable, and about 1 to 10 parts by weight is further preferable.

The component (D) is used to disperse the particles of the produced component (A). The component (D) is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, glycerin, pentaerythritol, polyethylene glycol, polypropylene glycol, and sorbitol. These may be used alone or in combination of two or more. Among them, a polyhydric alcohol having 2 to 10 carbon atoms is preferable, and ethylene glycol is more preferable, from the viewpoint of solubility in water and reduction of environmental load.

The amount of the component (D) used is not particularly limited, but is preferably about 1 to 15 parts by weight with respect to 100 parts by weight of the component (A) from the viewpoint of assisting the dispersion of the particles of the produced component (A). About 1 to 10 parts by weight is more preferable.

The physical properties of the obtained dispersion liquid for paper chemicals containing the component (A) are the extensional viscosity when the solid content concentration of the component (A) is 0.5% by weight in an aqueous solution (hereinafter, simply referred to as "extensional viscosity". )is important. The extensional viscosity is an index showing the thread pulling property of an aqueous solution obtained by diluting a so-called dispersion for paper chemicals, and measures the length of the thread extending from the liquid surface of the aqueous solution. In the present invention, the higher the extensional viscosity, the higher the drainage effect and the yield effect of the dispersion.

In the present invention, a special rod is attached to an aqueous solution prepared by adjusting the dispersion liquid for paper chemicals to 0.5% by weight in the solid content concentration of the component (A), and a constant speed is used using a material tester (manufactured by Lloyd) or the like. The length (unit: mm) of the thread stretched when pulled up in step 2 was taken as the value of the extensional viscosity. For the solid content concentration of the component (A), the total solid content weight of the monomer components (components (a1) to (a4)) forming the component (A) and the total weight of the dispersion liquid for paper manufacturing chemicals are used. Therefore, it can be calculated from the following (Equation 1) (the same applies hereinafter).

(Equation 1) {Concentration of solid content of component (A)} (%)
= [(Total weight of solid content of monomer component forming (A) component) / (Overall weight of dispersion for paper chemicals)] × 100

The extensional viscosity is usually 40 to 200 mm. When the extensional viscosity is less than 40 mm, when the dispersion liquid for paper chemicals containing the component (A) is added, the aggregation of pulp becomes weak, and the drainage effect and the yield effect tend to decrease. On the other hand, if it exceeds 200 mm, when the dispersion liquid for paper chemicals containing the component (A) is added, the pulp tends to be excessively agglomerated, causing paper breakage, or the texture is disturbed, and the paper strength effect tends to be inferior. From the same point of view, the extensional viscosity is preferably 40 to 200 mm, more preferably 50 to 180 mm.

As for the physical properties of the dispersion liquid for paper chemicals, the intrinsic viscosity (temperature 25 ° C.) (hereinafter, also referred to as “intrinsic viscosity”) of the liquid diluted with a 1N NaCl aqueous solution has excellent paper strength effect, drainage effect and It is an important parameter because it shows the yield effect. In the present invention, a dispersion for papermaking chemicals is diluted with a 1N NaCl aqueous solution to prepare a plurality of diluents having different solid content concentrations of the component (A), and each diluent is used with an Ubbelohde viscometer. The fall time (t) is measured. Next, the falling time (t0) was measured in the same manner with only a 1N NaCl aqueous solution, the specific viscosity (ηsp) was obtained from (Equation 2), and the vertical axis was divided by the solid content concentration of the component (A). The value and the solid content concentration of the component (A) are plotted on the horizontal axis, and the obtained straight section is used as the measured value of the intrinsic viscosity. NaCl is sodium chloride (the same applies hereinafter).

(Equation 2) Specific viscosity (ηsp) = (t / t0) -1

The intrinsic viscosity is usually 10 to 30 dl / g. When the intrinsic viscosity is less than 10 dl / g, when the dispersion liquid for paper chemicals containing the component (A) is added, the aggregation of pulp is weak and the drainage effect and the yield effect are difficult to be exhibited. On the other hand, if it exceeds 30 dl / g, when the dispersion liquid for paper chemicals containing the component (A) is added, the pulp tends to be excessively agglomerated and the paper may be cut, or the formation may be disturbed and the paper strength effect may be deteriorated. .. Further, for the same reason as described above, the intrinsic viscosity is preferably 10 to 30 dl / g, more preferably 12 to 25 dl / g.

Other physical properties of the dispersion for papermaking chemicals are not particularly limited, but for example, a diluted solution (temperature) obtained by diluting the dispersion with a 0.5-defined NaCl aqueous solution to a solid content concentration of the component (A) of 0.5%. The viscosity at 25 ° C.) is preferably about 20 to 300 mPa · s, more preferably about 50 to 200 mPa · s.

The particle size of the dispersion liquid for paper chemicals is about 0.1 to 150 μm from the viewpoint that it disperses well in the aqueous solution containing the component (B) and exhibits excellent paper strength effect, drainage effect and yield effect. Is preferable, and about 0.1 to 100 μm is more preferable.

One of the present inventions is a paper strength enhancer containing a dispersion for paper chemicals. As a result, the paper made can exert a good paper strength effect.

One of the present inventions is a drainage improver containing the above-mentioned dispersion liquid for paper manufacturing chemicals. As a result, drainage is improved in the dehydration process when the paper is made.

The present invention is one of the yield improvers for papermaking containing the dispersion liquid for papermaking chemicals. As a result, pulp fine fibers, paper strength enhancers, sizing agents, and other paper-making internal chemicals and ash can be retained in the paper, and the excellent effects of the paper-making internal chemicals can be exhibited. ..

The dispersion liquid for papermaking chemicals of the present invention is a chemical pulp such as broadleaf pulp (LBKP), coniferous pulp (NBKP), regardless of whether it is Western paper or paperboard; crushed wood pulp (GP), refiner ground pulp (RGP), thermomechanical pulp ( Mechanical pulp such as TMP); can be added to pulp slurries such as used paper pulp such as used cardboard. Two or more kinds of the pulp may be combined. In addition, paper-making chemicals such as sizing agent, paper strength enhancer, starch, aluminum sulfate, calcium carbonate, and talc may be added to the pulp slurry at the same time.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, "%" in the examples is based on weight. For convenience, monomers and the like are indicated by the following abbreviations.

AM: Acrylamide DMAEA-Q: Methyl chloride salt of N, N-dimethylaminoethyl acrylate DMAEA-BQ: benzyl chloride salt of N, N-dimethylaminoethyl acrylate IA: Itaconic acid AA: Acrylic acid EG: Ethylene glycol IPA: Isopropanol MBAA: N, N-methylenebisacrylamide DMAA: N, N-dimethylacrylamide SMAS: Sodium Metalyl Sulfonate V-50: 2,2'-azobis (2-amidinopropane) hydrochloride

[Extensional viscosity]
An aqueous solution was prepared by diluting the dispersion for paper chemicals with ion-exchanged water so that the solid content concentration of the component (A) was 0.5% in advance. 100 g of the aqueous solution was placed in a 140 ml glass container having an inner diameter of 4.5 cm and kept at 25 ° C. Using a rod (material: stainless steel, length 140 mm, diameter 2 mm) with a ball with a diameter of 10 mm at the tip, put the ball in the aqueous solution 20 mm from the liquid surface with the ball facing down, and perform an LRX type material test. Using a machine (manufactured by Lloyd), the rod was pulled up at a speed of 1000 mm / min, and the length (unit: mm) of the thread extending from the liquid surface was measured.

[Intrinsic viscosity]
A solution obtained by diluting the dispersion for papermaking chemicals with a 1N NaCl aqueous solution so that the solid content concentration of the component (A) is 0.02 g / dl, 0.04 g / dl, 0.06 / dl, 0.08 g / dl. Was kept at 25 ° C., and each drop time (t) was measured using an Ubbelohde viscometer. Similarly, the falling time (t0) of the 1N NaCl aqueous solution was also measured, and the specific viscosity (ηsp) was calculated from (Equation 2).
(Equation 2) ηsp = (t / t0) -1
The value (ηsp / c) obtained by dividing the obtained ηsp by the solid content concentration (c) of the component (A) is plotted on the vertical axis, and the solid content concentration (c) of the component (A) is plotted on the horizontal axis. The straight section obtained was defined as the intrinsic viscosity (unit: dl / g).

[Salt viscosity]
The viscosity of the diluted solution (25 ° C.) obtained by diluting the dispersion for papermaking chemicals with a NaCl aqueous solution of 0.5 definition so that the solid content concentration of the component (A) is 0.5% is measured by a B-type viscometer (Shibaura System (Shibaura System) Co., Ltd.) was used for measurement.

(Preparation of polymer dispersant (C-1))
Manufacturing example 1
249.98 g (solid content 199.98 g; 99.99 mol) of 80% DMAEA-Q aqueous solution in a 2 liter five-port separable flask equipped with a stirrer, thermometer, reflux condenser and nitrogen introduction tube. %), 0.02 g (0.01 mol%) of SMAS, and 529.6 g of ion-exchanged water were charged and replaced with nitrogen while heating at 60 ° C. To this, 20 g of a 2% V-50 aqueous solution was added as a polymerization initiator, and polymerization was carried out under stirring. The temperature rose due to self-heating, and polymerization was carried out at 80 ° C. for 1 hour to obtain a polymer dispersant (C-1). The obtained polymer dispersant (C-1) was adjusted to a solid content concentration of 20%. The results are shown in Table 1 (the same applies hereinafter).

Production Examples 2, 3
Polymer dispersants (C-2) and (C-3) were obtained by synthesizing according to Production Example 1 except that the composition was changed to that shown in Table 1.

(Preparation of (meth) acrylamide polymer (A-1))
Example 1
100.0 g (solid content concentration 20%) of (C-1) as the component (C) in a 2-liter five-port separable flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube. , 5 g with respect to 100 g of the obtained dispersion for papermaking chemicals (solid content of component (A))), 400.0 g of ammonium sulfate and 100.0 g of sodium sulfate were dissolved in 721.93 g of ion-exchanged water. To this, 389.06 g (solid content 194.53 g; 73.0 mol%) of 50% AM aqueous solution, 181.47 g (solid content 145.18 g; 20.0 mol%) of 80% DMAEA-Q aqueous solution, 75 67.39 g (solid content 50.54 g; 5.0 mol%) of DMAEA-BQ aqueous solution, 9.75 g (2.0 mol%) of IA, 10.0 g of EG as a component (D) (at the time of adding the polymerization initiator) 0.5%) was added to the reaction charge amount of the above, and the temperature was raised to 55 ° C. while substituting with nitrogen. To this, 20.0 g of a 2% V-50 aqueous solution was added as a polymerization initiator, and polymerization was carried out for 7 hours under stirring to obtain a (meth) acrylamide polymer (A-1). Table 2 shows the composition and physical properties (the same applies hereinafter).

Examples 2-22, Comparative Examples 1-7
With the composition shown in Table 2, the same procedure as in Example 1 was carried out to obtain (meth) acrylamide-based polymers (A-2) to (A-22) and (E-1) to (E-3), respectively. In Comparative Examples 4 to 7, since they were thickened and solidified during production, they were not subjected to the following evaluation.

(Preparation of diluted solution of dispersion for paper chemicals)
(Meta) Acrylamide polymers (A-1) to (A-22) and (E-1) to (E-3) are mixed with ion-exchanged water so that the solid content concentration of the component (A) is 0.1% by weight. A diluted solution of a dispersion for paper chemicals was prepared.

(Papermaking evaluation)
The waste paper was beaten with a Niagara beater to adjust the volume to 350 ml of Canadian Standard Freeness (CSF) to obtain a pulp slurry having a solid content concentration of 1.0% by weight. Next, 1.0% by weight of aluminum sulfate was added to the solid content of the pulp slurry to prepare a pulp slurry having a pH of 7.0, and then a diluted solution of a dispersion for paper chemicals was applied to the solid content of the pulp slurry. 0.02% by weight was added by weight, and the mixture was dehydrated with a tappi sheet machine. The obtained wet paper is pressed at 5 kg / cm ² for 2 minutes, dried in a rotary dryer at a temperature of 105 ° C for 4 minutes, and then humidity-controlled for 24 hours under the conditions of a temperature of 23 ° C and a humidity of 50%. A paper having an amount of 150 g / m ² was obtained. The specific burst strength of the obtained paper was measured by the following method.

(Specific burst strength)
Measured according to JIS P8131.

At the time of the above papermaking, 500 ml of pulp slurry after adding all the chemicals was put into DDJ (Dynamic Drainage Jar, 40 mesh), and the lower part was stirred at 2000 rpm using a stirrer equipped with turbine blades. 100 ml of filtered water was collected from the holes, the weight thereof was measured, and then suction filtration was performed using No. 2 filter paper. It was dried in a circulating air dryer at a temperature of 110 ° C. for 60 minutes, and the weight after drying was measured to determine the concentration of the filtrate collected from the prepared hole. Separately, the pulp slurry concentration after the addition of chemicals was calculated in advance by the same method, and the total yield (OPR) was obtained from (Equation 3).
(Equation 3) OPR (%) = {(Y1-Y2) / Y1} × 100
(Y1: Concentration of pulp slurry after adding all chemicals, Y2 = Concentration of filtrate collected from pilot hole)

In addition, the amount of filtered water of the pulp slurry after all the chemicals were added as described above was also measured according to JIS P8121. The above results are shown in Table 2.

Claims (11)

A dispersion for paper chemicals containing the (meth) acrylamide polymer (A).
The dispersion contains two or more salts (B) selected from the group consisting of ammonium salt, sodium salt and potassium salt.
The extensional viscosity of the dispersion liquid when the solid content concentration of the component (A) was made into a 0.5% by weight aqueous solution was 40 to 200 mm.
A dispersion for paper chemicals, which has an intrinsic viscosity (temperature 25 ° C.) of 10 to 30 dl / g obtained by diluting the dispersion with a 1N NaCl aqueous solution. The dispersion liquid for paper chemicals according to claim 1, wherein the component (A) contains a polymer of a monomer component containing (meth) acrylamide (a1) and a cationic unsaturated monomer (a2). The dispersion for paper chemicals according to claim 2, wherein the component (a2) is a tertiary amino group-containing (meth) acrylate and / or a quaternized salt of the (meth) acrylate. The dispersion liquid for paper chemicals according to claim 2 or 3, wherein the monomer component further contains an anionic unsaturated monomer (a3). The dispersion liquid for paper chemicals according to claim 4, wherein the component (a3) is at least one selected from the group consisting of acrylic acid, itaconic acid and itaconic anhydride. The dispersion for paper chemicals according to any one of claims 1 to 5, wherein the component (B) contains ammonium sulfate and sodium sulfate and / or sodium chloride. The dispersion liquid for paper chemicals according to any one of claims 1 to 6, wherein the content of the component (B) is 15 to 45% by weight with respect to 100% by weight of the dispersion liquid for paper chemicals. The dispersion liquid for paper chemicals according to any one of claims 1 to 7, further comprising a polymer dispersant (C) and / or a polyhydric alcohol (D). A paper strength enhancer containing the dispersion liquid for paper chemicals according to any one of claims 1 to 8. A drainage improver containing the dispersion liquid for paper chemicals according to any one of claims 1 to 8. A yield improver containing the dispersion for paper chemicals according to any one of claims 1 to 8.