JP6907626B2 - Dispersion liquid for paper chemicals, manufacturing method of dispersion liquid for paper chemicals, paper strength enhancer containing dispersion liquid for paper chemicals, drainage improver for papermaking and yield improver for papermaking - Google Patents

Description

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

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

There are various forms of such paper chemicals. For example, a dispersion obtained by dispersing and polymerizing a monomer component mainly composed of acrylamide in a salt aqueous solution can be mentioned as a chemical having a paper strength enhancement, drainage and retention effect. As such a dispersion liquid 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 content, etc. in the paper.

As a method for producing a dispersion having a high intrinsic viscosity, a method of polymerizing at a low temperature for a long time is known in order to control thickening of the reaction solution at the time of polymerization and reduce residual monomers (Patent Document 1 and). 2).

In Patent Document 1, a water-soluble polymer obtained by coexisting a polymerization polymer and a polycondensation polymer soluble in a salt aqueous solution as a dispersant and dispersing and polymerizing a monomer (mixture) in a salt aqueous solution with stirring. A method for producing a polymer dispersion is disclosed, which describes keeping the monomer mixture at 33 to 35 ° C., adding an initiator to polymerize for 8 hours, and further adding an initiator to polymerize for 8 hours. In Patent Document 2, a soluble polymer dispersant is allowed to coexist in a salt aqueous solution, a specific amount of a polymerization retardant substance is added together with a vinyl monomer or a mixture of vinyl monomers, and dispersion polymerization is carried out with stirring. The technique of the obtained dispersion is disclosed, and it is described that the monomer mixture is adjusted to 35 ± 2 ° C., an initiator is added and polymerized for 6 hours, and then an initiator is added and polymerized for 10 hours.

However, these methods have a problem that the polymerization time is very long and the production efficiency is poor. Further, when the monomer components are polymerized at a low temperature for a short time, unreacted acrylamide tends to remain. On the other hand, when the monomer component is polymerized at a high temperature in order to increase the production efficiency, agglomerates are likely to be generated in the liquid due to the remarkably thickening at the time of polymerization, which causes poor dispersion. The agglomerates remain as undissolved substances when the dispersion liquid is diluted, and when added to a pulp slurry, for example, the paper becomes uneven, which may lead to paper breakage and the like. Further, if there are many agglomerates, it takes time to filter the obtained dispersion liquid, and the yield may be low.
Japanese Unexamined Patent Publication No. 2003-73566 Japanese Unexamined Patent Publication No. 2008-56752

The present invention contains a water-soluble polymer containing a small amount of unreacted acrylamide, has a high intrinsic viscosity, is a dispersion liquid for paper chemicals in which agglomerates are less likely to occur during polymerization, and shortens the polymerization time and at the time of polymerization. Provided are methods for producing a dispersion liquid for paper chemicals, which suppresses remarkable thickening and poor dispersion of the reaction liquid in the above, and further, a paper strength enhancer containing the dispersion liquid for paper chemicals, a drainage improver for paper making, and a paper making agent. The purpose is to provide a yield improver.

The present inventors have focused on the fact that not only the final product but also the physical properties of the dispersion during the polymerization are factors for improving the productivity and obtaining the dispersion for papermaking chemicals which is excellent in various effects when made into paper. As a result of diligent studies, we found a dispersion for papermaking chemicals that contains a water-soluble polymer with a small amount of unreacted acrylamide, has a high intrinsic viscosity, and is less likely to generate polymer-derived aggregates. In order to complete the present invention, it has been found that the above-mentioned problems can be particularly solved by a production method in which the polymerization reaction rate and the intrinsic viscosity of the water-soluble polymer are controlled at a specific time from the addition of the polymerization initiator in the case of dispersion polymerization. It arrived.

That is, the present invention is the following items 1 to 13.
Item 1
A dispersion liquid for paper chemicals containing a water-soluble polymer (A), a polymer dispersant (B), and a polyhydric alcohol (C).
The water-soluble polymer (A) is a monomer component containing (meth) acrylamide (a1) and a cationic radically polymerizable monomer (a2) (however, it does not contain metharylsulfonic acid and / or a salt thereof). In the polymer, unreacted (meth) acrylamide (a1) is 2000 ppm or less, the weight ratio of aggregates in the dispersion is 1% by weight or less, and the intrinsic viscosity (temperature) in a 1N aqueous solution of NaCl. A dispersion for papermaking chemicals having a temperature of 5 to 30 dl / g (25 ° C.).

Item 2
The dispersion liquid for paper chemicals according to item 1 above, wherein the monomer component contains 20 to 95 mol% of acrylamides (a1) and 5 to 40 mol% of a cationic radically polymerizable monomer (a2).

Item 3
Item 1 or the above, wherein the water-soluble polymer (A) is a polymer of a monomer component further containing an anionic radically polymerizable monomer (a3) (however, it does not contain metharylsulfonic acid and / or a salt thereof). 2. The dispersion liquid for papermaking chemicals according to 2.

Item 4
The dispersion liquid for paper chemicals according to any one of Items 1 to 3 above, wherein the cationic radically polymerizable monomer (a2) has an amino group-containing (meth) acrylate group.

Item 5
The anionic radically polymerizable monomer (a3) (however, not containing metallyl sulfonic acid and / or a salt thereof) is at least one selected from the group consisting of acrylic acid, itaconic acid and itaconic anhydride. The dispersion liquid for papermaking chemicals according to the preceding item 3.

Item 6
The polymer dispersant (B) contains 30 to 99.99 mol% of a cationic radically polymerizable monomer (b1) and 0.01 to 1 mol of a sulfonic acid group-containing monomer and / or a salt thereof (b2). The dispersion liquid for papermaking chemicals according to any one of the above items 1 to 5, which is a copolymer of a reactant containing%.

Item 7
The dispersion liquid for paper chemicals according to any one of the above items 1 to 6, wherein the amount of the polymer dispersant (B) used is 1 to 10 parts by weight with respect to 100 parts by weight of the water-soluble polymer (A).

Item 8
The dispersion liquid for paper chemicals according to any one of the above items 1 to 7, wherein the polyhydric alcohol (C) has 2 to 10 carbon atoms.

Item 9
In the presence of the polymer dispersant (B) and the polyhydric alcohol (C), the step of forming the water-soluble polymer (A) by dispersion polymerization of the monomer component in a salt aqueous solution having a saturation concentration or less is included.
The temperature of the step is 15 to 70 ° C.
The method for producing a dispersion for paper chemicals according to any one of claims 1 to 8, wherein the polymerization reaction rate in this step is 2 to 40% when 2 hours have passed from the start of addition of the polymerization initiator.

Item 10
The intrinsic viscosity (temperature 25 ° C.) of the reaction solution containing the components (A), (B) and (C) in the 1N NaCl aqueous solution 2 hours after the start of addition of the polymerization initiator is 0.5. The method for producing a dispersion liquid for paper chemicals according to item 9 above, wherein the content is ~ 12 dl / g.

Item 11
A paper strength enhancer containing the dispersion liquid for paper chemicals according to any one of the above items 1 to 8.

Item 12
A papermaking drainage improving agent containing the dispersion liquid for papermaking chemicals according to any one of the above items 1 to 8.

Item 13
A yield improver for papermaking containing the dispersion liquid for papermaking chemicals according to any one of the above items 1 to 8.

According to the present invention, it is possible to provide a dispersion liquid for paper chemicals, which contains a water-soluble polymer containing a small amount of unreacted acrylamide, has a high intrinsic viscosity, and is less likely to cause agglutination during polymerization. Further, it is possible to provide a method for producing a dispersion liquid for paper chemicals, in which the polymerization time is shortened as compared with the conventional case, and the thickening of the reaction liquid and the poor dispersion are suppressed. Further, since the dispersion liquid for paper chemicals of the present invention has a high paper strength effect, drainage, and yield improving effect, it is decided to use it as a paper strength enhancer, a papermaking drainage improving agent, and a papermaking yield improving agent. Suitable.

The dispersion liquid for paper chemicals of the present invention is also referred to as a water-soluble polymer (A) (hereinafter, also referred to as “(A) component”) and a polymer dispersant (B) (hereinafter, also referred to as “(B) component”). ) And the polyhydric alcohol (C) (hereinafter, also referred to as “component (C)”). Hereinafter, the description will be given sequentially.

<About (A) component>
The component (A) is also referred to as (meth) acrylamide (a1) (hereinafter, also referred to as “component (a1)”) and a cationic radically polymerizable monomer (a2) (hereinafter, also referred to as “component (a2)”). ) (However, it does not contain metallic sulfonic acid and / or a salt thereof).

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

The component (a2) is not particularly limited as long as it is a cationic radically polymerizable monomer, and examples thereof include the same monomers as the component (b1). Among these, those having an amino group-containing (meth) acrylate group are preferably used from the viewpoint of high copolymerizability with the component (a1).

Examples of those having the amino group-containing (meth) acrylate group include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and quaternized products thereof. .. Among these, the component (A) to be produced is preferably a quaternized product of N, N-dimethylaminoethyl (meth) acrylate in that it has high hydrophobicity and is difficult to dissolve in an aqueous salt solution. It is preferably a quaternized product of acryloyloxyethyl trimethylammonium chloride and N, N-dimethylaminoethyl acrylate benzyl chloride.

The contents of the component (a1) and the component (a2) are 20 to 95 mol% for the component (a1) and 5 to 40 mol% for the component (a2). Thereby, a high molecular weight polymer can be obtained.

Examples of other monomer components include component (a3). The component (a3) is not particularly limited as long as it is an anionic radically polymerizable monomer, and examples thereof include acrylic acid, itaconic acid, itaconic anhydride, fumaric acid, and maleic acid. These may be used as alkali metal salts such as sodium and potassium, ammonium salts and the like. Among these, the group consisting of acrylic acid, itaconic acid and itaconic anhydride is preferable in that a dispersion having a high intrinsic viscosity can be obtained due to the high copolymerizability with the component (a1) and the component (a2). At least one selected from the above is used.

Although metallic sulfonic acid and / or a salt thereof is also applicable as the component (a3), the intrinsic viscosity of the dispersion liquid for paper chemicals is lowered, and the paper strength, drainage and yield effects cannot be sufficiently obtained. Therefore, it is not preferable. Here, examples of the salt of methallyl sulfonic acid include sodium metharyl sulfonate, potassium metharyl sulfonate, and the like.

When the monomer component contains the component (a1), the component (a2) and the component (a3) (however, it does not contain metharylsulfonic acid and / or a salt thereof), the respective contents are 20 to 95. It is preferably mol%, 5-40 mol%, and 0-40 mol%. More preferably, 40 to 93.5 mol%, 6.5 to 35 mol% and 0 to 25 mol%, particularly preferably 55 to 90 mol%, in that a dispersion having a high intrinsic viscosity can be obtained. , 10-30 mol% and 0-15 mol%.

Further, as long as the above-mentioned monomer component contains the components (a1) to (a3) (however, it does not contain metallyl sulfonic acid and / or a salt thereof) within the above-mentioned content range, ( A radically polymerizable monomer (a4) other than the components a1) to (a3) (hereinafter, also referred to as “component (a4)”) may be contained. Examples of the component (a4) include N, N-dimethylacrylamide, N, N-diethyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N-methyl (meth) acrylamide, and N-ethyl (meth). Cross-linking of acrylamide, N-isopropyl (meth) acrylamide, N-t-butyl (meth) acrylamide, N, N-methylenebisacrylamide, 1,3,5-triacrylhexahydro-1,3,5-triazine, etc. Aromatic vinyl monomers such as sex monomers, styrene, α-methylstyrene, vinyltoluene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, ( Examples thereof include alkyl (meth) acrylates such as -2-ethylhexyl acrylate and cyclohexyl (meth) acrylate, and carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate. These may be used alone or in combination of two or more. The amount of the component (a4) used is less than 10 mol%, with the total amount of the components (a1) to (a4) being 100 mol%.

Further, the above-mentioned monomer component may contain other components. Other components include, for example, organic acids such as citric acid, 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, and defoaming. Examples include agents and antioxidants.

The component (B) is not particularly limited as long as it is a high molecular weight dispersant, and for example, 30 to 99.99 mol of the cationic radically polymerizable monomer (b1) (hereinafter, also referred to as “component (b1)”). %, And a copolymer of a reactant containing 0.01 to 1 mol% of a sulfonic acid group-containing monomer and / or a salt thereof (b2) (hereinafter, also referred to as “component (b2)”). .. By using the component (B), it is easy to improve the dispersibility of the water-soluble polymer.

Examples of the component (b1) include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylamino. Tertiary amino group-containing (meth) acrylic monomer such as propyl (meth) acrylamide, salt of tertiary amino group-containing (meth) acrylic monomer, tertiary amino group-containing (meth) acrylic monomer and quaternary Examples thereof include a quaternary ammonium salt-containing (meth) acrylic monomer obtained by reacting an agent. 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 these, acryloyloxyethyltrimethylammonium chloride is preferable from the viewpoint of maintaining the solubility of the polymer in the aqueous salt solution and improving the dispersibility.

The component (b2) 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 radically polymerizable functional group, and known components are used. be able to. For example, sulfonic acid group-containing unsaturated monomers having an allyl group such as allyl sulfonic acid, sodium allyl sulfonate, metharyl sulfonic acid, sodium metharyl sulfonate, ammonium metharyl sulfonate, vinyl sulfonic acid, styrene sulfonic acid, Examples thereof include 2-acrylamide-2-methylpropanesulfonic acid. Among these, sodium (meth) allylsulfonate is preferable in that radical transfer (chain transfer) is likely to occur and the molecular weight and crosslinked structure can be easily adjusted.

Further, the reactant of the component (B) is, if necessary, radical polymerization other than the components (b1) to (b2) as long as the above components (b1) and (b2) are contained within the above range of the amount used. The sex monomer (b3) (hereinafter, also referred to as “(b3) component”) may be contained. Examples of the component (b3) include N, N-dimethylacrylamide, N, N-diethyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N-methyl (meth) acrylamide, and N-ethyl (meth). Cross-linking of acrylamide, N-isopropyl (meth) acrylamide, N-t-butyl (meth) acrylamide, N, N-methylenebisacrylamide, 1,3,5-triacrylhexahydro-1,3,5-triazine, etc. Aromatic vinyl monomers such as sex monomers, styrene, α-methylstyrene, vinyltoluene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, ( -2-ethylhexyl acrylate, alkyl (meth) acrylates such as cyclohexyl (meth) acrylate, vinyl carboxylic acid esters such as vinyl acetate and vinyl propionate, (meth) acrylate, fumaric acid, maleic acid, Examples thereof include carboxyl group-containing monomers such as maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride, acrylamide, and methacrylicamide. These may be used alone or in combination of two or more. Among these, acrylamide, N, N-dimethylacrylamide, and N, N-methylenebisacrylamide are preferable from the viewpoint of high copolymerizability with the components (b1) to (b2). The amount of the component (b3) used is less than 30 mol%, where the total amount of the components (b1) to (b3) is 100 mol%.

The amount of the component (B) used is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the component (A). If the amount is less than 1 part by weight, the amount of the component (B) is small, so that the polymer in the component (A) is difficult to disperse in the aqueous salt solution. It adversely affects the performance of paper chemicals such as water and retention effect.

The component (C) is used to disperse the particles of the produced polymer, and is not particularly limited as long as it is a polyhydric alcohol. Examples of the component (C) include ethylene glycol, propylene glycol, glycerin, pentaerythritol, polyethylene glycol, polypropylene glycol, glycerin, pentaerythritol, and sorbitol. Among these, a polyhydric alcohol having 2 to 10 carbon atoms is preferable, and ethylene glycol and glycerin are more preferable, from the viewpoint of solubility in water and reduction of environmental load.

In the method for producing a dispersion liquid for papermaking chemicals of the present invention, the water-soluble polymer (A) is obtained by dispersing and polymerizing the monomer in a salt aqueous solution having a saturation concentration or less in the presence of the components (B) and (C). The temperature of the step is 15 to 70 ° C., and the polymerization reaction rate of the step is 2 to 40% 2 hours after the start of addition of the polymerization initiator.

As the dispersion polymerization, for example, the component (a1), the component (a2), the component (B) and the component (C), and if necessary, the component (a3) are mixed in an aqueous salt solution to obtain known mechanical dispersion and the like. The method of is adopted. Among them, from the viewpoint of obtaining a dispersion liquid having a desired polymerization rate and intrinsic viscosity, after mixing the above components, the temperature is adjusted to 15 to 70 ° C., a polymerization initiator is added, and then polymerization is carried out for 5 to 9.5 hours. Is preferable. More preferably, it is 6 to 9 hours. The polymerization temperature differs depending on the type of the polymerization initiator and may be any temperature at which the polymerization initiator functions. Further, the monomer component to be used may be added dropwise, and the salt may be added in parts such as during the polymerization or mixed after the polymerization. The polymerization initiator may be added all at once or separately.

The salt in the aqueous salt solution is not particularly limited as long as it does not dissolve the component (A), and is, for example, ammonium sulfate, sodium sulfate, magnesium sulfate, aluminum sulfate, ammonium hydrogen phosphate, sodium hydrogen phosphate, and phosphoric acid. Examples include potassium hydrogen hydrogen. Among these, ammonium sulfate is preferably used because it promotes the particle formation of the component (A) to be produced.

The concentration of the aqueous salt solution is less than or equal to the saturation concentration. As a result, the component (A) produced by dispersion polymerization can be precipitated as particles, and a dispersion liquid of the component (A) can be produced. Further, it is preferably 10% by weight or more and a saturation concentration or less in terms of making it easier to precipitate the produced component (A).

The step of forming the component (A) is 15 to 70 ° C. If it is less than 15 ° C., the polymerization reaction is difficult to proceed, and if it exceeds 70 ° C., the intrinsic viscosity of the dispersion is lowered, and the performance as a paper chemical is deteriorated. Further, from the viewpoint of satisfying the polymerization reaction rate of the component (A) and the intrinsic viscosity of the dispersion liquid, the temperature is preferably 30 to 60 ° C, more preferably 35 to 55 ° C.

The polymerization reaction rate in the above step is 2 to 40% 2 hours after the start of addition of the polymerization initiator. If the polymerization reaction rate is less than 2%, the subsequent polymerization reaction proceeds slowly, acrylamide remains at the end of polymerization, or the intrinsic viscosity of the dispersion liquid for paper chemicals becomes low, and the paper strength, drainage and yield effects are improved. It becomes difficult to obtain. Further, if it exceeds 40%, the progress of the polymerization reaction becomes fast, and a short polymer is produced, so that the intrinsic viscosity of the dispersion liquid for paper chemicals becomes low, and it becomes difficult to obtain paper strength, drainage and retention effects. Alternatively, thickening or poor dispersion is caused during polymerization, and agglomerates are likely to be generated in the dispersion liquid. Further, it is preferably 5 to 30%, more preferably 10 to 25%, from the viewpoint of making it difficult to form agglomerates while exhibiting good paper strength, drainage and yield effect. The polymerization reaction rate in the present invention represents the total amount of monomers before polymerization and the amount of monomer consumed when a specific time has passed from the start of polymerization. As a measuring method, the polymerization reaction rate after 2 hours can be obtained by calculating the monomer concentration before and 2 hours after adding the initiator of the reaction solution and substituting it into (Equation 1). The monomer concentration is calculated by taking out a part of the reaction solution, adding a polymerization inhibitor such as hydroquinone, and then measuring by liquid chromatography or the like.

(Formula 1) Polymerization reaction rate (%) = {(X1-X2) / X1} × 100
(X1: Monomer concentration in the reaction solution before the initiator is added, X2 = Monomer concentration in the reaction solution 2 hours after the addition)

The above-mentioned polymerization initiator is not particularly limited, and for example, persulfate such as ammonium persulfate, potassium persulfate, and sodium persulfate, and azo-based polymerization such as 2,2'-azobis (2-amidinopropane) hydrochloride. Initiators and the like can be mentioned. Among these, 2,2'-azobis (2-amidinopropane) hydrochloride is preferable because the cross-linking reaction during the polymerization reaction is unlikely to occur.

The amount of the polymerization initiator used is not particularly limited, but 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 a part.

In the above step, the intrinsic viscosity (temperature 25 ° C.) of the dispersion liquid intermediate for paper chemicals in a 1N NaCl aqueous solution 2 hours after the start of addition of the polymerization initiator is 0.5 to 12 dl / g. Is preferable. If it is less than 0.5 dl / g, the progress of the polymerization reaction is slow, acrylamide remains at the end of the polymerization, or the intrinsic viscosity of the dispersion liquid for paper chemicals tends to be lower than the desired value. On the other hand, if it exceeds 12 dl / g, thickening and poor dispersion are caused during polymerization, and agglomerates are likely to be generated in the dispersion liquid. Further, from the viewpoint that the dispersion liquid obtains good performance as a paper-making chemical such as paper strength and drainage effect, it is more preferably 0.8 to 10 dl / g, and particularly preferably 1 to 8 dl / g. The intrinsic viscosity was measured by preparing a diluted solution obtained by diluting the dispersion liquid for papermaking chemicals with a 1N NaCl aqueous solution to a predetermined concentration and using an Ostwald viscometer.

The obtained component (A) is characterized in that the amount of unreacted component (a1) is small in terms of reducing the environmental load and obtaining good performance as a paper-making chemical such as paper strength and drainage effect. The content of the unreacted component (a1) may be measured by liquid chromatography or the like. From the same point as above, the content of the unreacted component (a1) contained in the dispersion liquid for paper chemicals is usually 2000 ppm or less, preferably 1000 ppm or less in terms of solid content.

The dispersion liquid for paper chemicals containing the component (A) usually has an intrinsic viscosity (temperature 25 ° C.) in a 1N NaCl aqueous solution because it obtains good performance as a paper chemical such as paper strength and drainage effect. Is 5 to 30 dl / g, preferably 12 to 25 dl / g.

Further, the dispersion liquid for paper manufacturing chemicals of the present invention is unlikely to generate agglomerates. The agglomerates contained in the dispersion liquid for paper chemicals of the present invention are the coalescence of particles generated by causing poor dispersion during polymerization during the production of the component (A). The weight ratio of the agglomerates to the dispersion liquid for paper chemicals of the present invention is 1% by weight or less, preferably 0.8% by weight or less in terms of solid content, from the viewpoint that the dispersion liquid for paper chemicals exhibits excellent solubility. More preferably, it is 0.5% by weight or less. The weight ratio is calculated using (Equation 2).
(Equation 2) Weight ratio of agglomerates to the dispersion liquid (%) = (Weight of agglomerates (solid content) (g)) / (Weight of dispersion liquid for paper chemicals (g)) × 100

The measurement of the weight ratio is not particularly limited, and examples thereof include a method of naturally filtering the dispersion liquid for paper making chemicals as it is using a mesh (wire mesh) or the like. When the dispersion liquid for paper chemicals is naturally filtered, the filtrate is attached to the aggregates and the wire mesh after filtration, so it is necessary to press a waste cloth or the like from under the wire mesh to wipe it off. Further, since the agglomerates after wiping off the filtrate contain water, it is preferable to dry them under heating. The drying conditions are not particularly limited, but are, for example, a temperature of about 100 to 160 ° C. (preferably about 105 to 140 ° C.) and a time of about 0.5 to 5 hours (preferably about 1 to 4 hours).

Other physical properties of the dispersion liquid for paper chemicals are not particularly limited, but are, for example, 300 to 2500 mPa · s in a diluted liquid (temperature 25 ° C.) diluted to a concentration of 1% with deionized water.

The particle size of the dispersion liquid for paper chemicals is usually 0.1 to 150 μm, preferably 0.1 to 100 μm from the viewpoint of paper strength, drainage, dispersion stability of particles, and yield effect.

A paper strength enhancer containing the above-mentioned dispersion for paper chemicals is also one of the present inventions. As a result, the paper produced can exert a good paper strength effect.

A paper-making drainage improver containing the above-mentioned dispersion liquid for paper-making chemicals is also one of the present inventions. As a result, drainage is improved in the dehydration process during papermaking.

A yield improver for papermaking containing the dispersion liquid for papermaking chemicals is also one of the present inventions. As a result, pulp fine fibers, paper strength agents, paper-making additives such as sizing agents, and ash can be retained in the paper, and the excellent effects of various additives can be exhibited.

The dispersion for paper chemicals obtained by the production method of the present invention can be used for both paper and paperboard, and can be used for sizing agents, paper strength agents, aluminum sulfate, organic / inorganic fine particle agglutination aids, and the like. Papermaking additives may also be used 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, parts or% in the examples are based on weight. For convenience, monomers and the like are indicated by the following abbreviations.

AM: Acrylamide DMAEA-Q: Acryloyloxyethyl trimethylammonium chloride DMAEA-BQ: Quartized product of N, N-dimethylaminoethyl acrylate benzyl chloride DML: Quartified product of N, N-dimethylaminoethyl methacrylate benzyl chloride 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- Acrylamide) hydrochloride

[Polymerization reaction rate]
The reaction solutions before and 2 hours after the addition of the initiator were subjected to HPLC using the following eluent, the monomer concentration was calculated from the amount of UV light absorbed, and then the polymerization reaction rate was calculated from (Equation 1). The measurement conditions are as follows.
(Measurement condition)
Column: Shiseido CAPCELL PAC C18 MG II S5; 1.5 mm I. D. × 250 mm
Eluent: Water / acetonitrile = 65/35 solution containing N / 100 sodium dodecyl sulfate (adjusted to pH 2.3 with phosphoric acid)
Detector: Shiseido NANOSPACE SI-2 UV-VIS detector 3002
Detection wavelength: 205 nm
(Formula 1) Polymerization reaction rate (%) = {(X1-X2) / X1} × 100
(X1: Monomer concentration in the reaction solution before the initiator is added, X2 = Monomer concentration in the reaction solution 2 hours after the addition)

[Content of unreacted component (a1)]
The dispersion liquid for paper chemicals containing the component (A) was subjected to HPLC using the above eluent, and the content of the unreacted component (a1) was calculated.

[Weight ratio of agglomerates in the dispersion liquid for paper chemicals]
100 g of the paper chemical dispersion was filtered through a pre-weighed 40-mesh wire mesh. A waste cloth was pressed from under the wire mesh to wipe off the filtrate adhering to the wire mesh, and then the wire mesh was dried in a circulation dryer at a temperature of 105 ° C. for 3 hours. The weight of the agglomerates (solid content) after drying was measured and calculated by (Equation 2).
(Equation 2) Weight ratio of agglomerates to the dispersion liquid (%) = (Weight of agglomerates (solid content) (g)) / (Weight of dispersion liquid for paper chemicals (g)) × 100

[Intrinsic viscosity]
The active component concentration (c) is 0.02 g / dl, 0.04 g / dl, 0.06 / dl, 0.08 g / with a 1N NaCl aqueous solution of the reaction solution or the dispersion liquid for papermaking chemicals 2 hours after the addition of the initiator. The liquid diluted to dl was kept warm at 25 ° C., and the respective fall times (t) were measured using an Ostwald viscometer. The active ingredient concentration (c) means the polymer component concentration of the component (A) and the component (B) in the liquid (if the monomer component remains in the liquid, its content is also taken into consideration). Similarly, the falling time (t0) of the 1N NaCl aqueous solution was also measured, and the specific viscosity (ηsp) was calculated from (Equation 3).
(Equation 3) ηsp = (t / t0) -1
The value obtained by dividing the obtained ηsp by the polymer concentration (ηsp / c) is plotted on the vertical axis and the polymer concentration (c) is plotted on the horizontal axis, and the obtained straight section is plotted with the intrinsic viscosity (unit: dl /). g).

[viscosity]
The viscosity of the sample liquid (25 ° C.) obtained by diluting the dispersion liquid for papermaking chemicals with ion-exchanged water so that the active ingredient concentration (c) becomes 1% is measured using a B-type viscometer (manufactured by Shibaura System Co., Ltd.). did.

(Preparation of polymer dispersant)
Manufacturing example 1
249.98 g (pure 199.98 g; 99.99 mol) of 80% DMAEA-Q aqueous solution in a 2 liter five-neck separable flask equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet tube. %), 0.02 g (0.01 mol%) of SMAS, and 529.2 g of ion-exchanged water were charged and replaced with nitrogen while heating at 60 ° C. To this, 20 g of a 4% 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 (B-1). The obtained polymer dispersant (B-1) was adjusted to have a non-volatile content of 20%. The results are shown in Table 1 (the same applies hereinafter).

Production Examples 2, 3
The polymer dispersants (B-2) and (B-3) were obtained by synthesizing according to Production Example 1 except that the compositions were changed to those shown in Table 1.

(Preparation of dispersion for paper chemicals)
Example 1
In a 2-liter five-port separable flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube, 100. 0 g (20% non-volatile content; 8.0 parts with respect to 100 parts of the obtained water-soluble polymer (A-1)) and 450.0 g of ammonium sulfate were dissolved in ion-exchanged water 674.76. To this, 198.4 g (pure content 99.2 g; 69 mol%) of 50% AM aqueous solution, 48.94 g (pure content 39.15 g; 10.0 mol%) of 80% DMAEA-Q aqueous solution, and 75%. 145.4 g (pure content 109.05 g; 20.0 mol%) of DMAEA-BQ aqueous solution, 2.63 g (1.0 mol%) of IA, and 1.25 g of EG (reaction charge at the time of adding the polymerization initiator) as the component (C). 0.50 part) was added to the amount, and the temperature was raised to 55 ° C. while substituting with nitrogen. To this, 20 g of a 1% V-50 aqueous solution was added as a polymerization initiator, and polymerization was carried out for 7 hours under stirring to obtain a water-soluble polymer (A-1) dispersed in a salt aqueous solution. In addition, (A-1) was collected 2 hours after the addition of the polymerization initiator, and it was confirmed that the polymerization rate was 25% and the intrinsic viscosity was 7.8 dl / g. Table 2 shows the composition and physical characteristics (the same applies hereinafter).

Examples 2-4
In Example 1, by changing the amount of the 1% V-50 aqueous solution used, the polymerization reaction rate 2 hours after the start of polymerization was adjusted to be as shown in Table 2, and the same synthesis was carried out to obtain a water-soluble polymer (A). -2)-(A-4) were obtained.

Examples 5 to 15, Comparative Example 3
In Example 1, the monomer components in Table 2 were similarly synthesized to obtain water-soluble polymers (A-5) to (A-15) and (A-28).

Examples 16 and 17
In Example 1, the component (B) was changed to (B-2) and (B-3) and synthesized in the same manner to obtain water-soluble polymers (A-16) to (A-17).

Example 18
In Example 1, the component (C) was changed to glycerin and synthesized in the same manner to obtain a water-soluble polymer (A-18).

Examples 19-21, Comparative Examples 1 and 2
In Example 1, the polymerization temperatures shown in Table 2 were changed and the same synthesis was performed to obtain water-soluble polymers (A-19) to (A-21), (A-26), and (A-27). ..

Examples 22 and 23
In Example 21, by changing the amount of the 1% V-50 aqueous solution used, the polymerization reaction rate 2 hours after the start of polymerization was adjusted to be as shown in Table 2, and the same synthesis was carried out to obtain a water-soluble polymer (A). -22) and (A-23) were obtained.

Examples 24, 25
In Example 1, the polymerization time was changed to 9 hours (Example 24) and 6 hours (Example 25), and the same synthesis was carried out to obtain water-soluble polymers (A-24) and (A-25). ..

Comparative Example 4
In Example 1, the component (C) was changed to IPA and synthesized in the same manner to obtain a water-soluble polymer (A-29).

Comparative Example 5
In Example 1, the same synthesis was carried out without using the component (B) to obtain a water-soluble polymer (A-30).

Comparative Example 6
In Example 1, the same synthesis was carried out without using the component (C) to obtain a water-soluble polymer (A-31).

(Preparation of diluted solution of dispersion for paper chemicals)
The water-soluble polymers (A-1) to (A-31) were diluted with deionized water to 0.1% by weight to prepare a diluted solution of a dispersion for paper chemicals.

(Evaluation Examples 1 to 25, Comparative Evaluation Examples 1 to 6)
The step ball waste paper was beaten with a Niagara beater and adjusted to 280 ml of Canadian Standard Freeness (CSF) to obtain a paper material having a solid content concentration of 1.0% by weight. Next, a sulfate band of 1.0% by weight was added to the solid content of the paper material to prepare a pulp slurry having a pH of 7.0. Next, a dispersion for paper chemicals was added to the pulp slurry in an amount of 0.02% by weight based on the solid content of the paper material in the pulp slurry, and the pulp slurry was dehydrated by a tappy sheet machine. The obtained wet paper was pressed at 5 kg / cm2 for 2 minutes, and the obtained paper was dried in a rotary dryer at 105 ° C. for 4 minutes, and then 23 ° C., 50% R.M. H. The humidity was adjusted for 24 hours under the above conditions to obtain a paper having ^{a basis weight of 150 g / m 2.} The specific burst strength and the coefficient of variation of the formation of the obtained paper were measured.

At the same time, 500 ml of the pulp slurry after adding the above chemicals was placed in a blit jar (40 mesh), and 100 ml of filtered water was collected from the prepared hole (2000 rpm) while stirring using a stirrer equipped with turbine blades, and the weight thereof was measured. After that, suction filtration was performed with No. 2 filter paper. It was dried in a circulating air dryer at 110 ° C. for 60 minutes, the weight after drying was measured, and the concentration of the filtrate collected from the prepared hole was determined. 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 4).
(Equation 4) OPR (%) = {(Y1-Y2) / Y1} × 100
(Y1: Concentration of pulp slurry after chemical addition, Y2 = concentration of filtrate collected from pilot hole)

In addition, the amount of filtered water of the pulp slurry after the addition of the above chemicals was also measured. The amount of drained water was measured according to JIS P8121, and the specific burst strength was measured according to JIS P8131. The above evaluation results are shown in Table 3.

Claims (12)

A dispersion liquid for paper chemicals containing a water-soluble polymer (A), a polymer dispersant (B), and a polyhydric alcohol (C).
The water-soluble polymer (A) is a monomer component containing (meth) acrylamide (a1) and a cationic radically polymerizable monomer (a2) (however, it does not contain metallic sulfonic acid and / or a salt thereof). In the polymer, unreacted (meth) acrylamide (a1) is 2000 ppm or less, the weight ratio of aggregates in the dispersion is 1% by weight or less, and the intrinsic viscosity (temperature) in 1N aqueous NaCl solution. 25 ℃) Ri is 5~30dl / g der,
The polymer dispersant (B) contains 30 to 99.99 mol% of a cationic radically polymerizable monomer (b1) and 0.01 to 1 mol of a sulfonic acid group-containing monomer and / or a salt thereof (b2). A dispersion for papermaking chemicals, which is a copolymer of a reactant containing%. The dispersion for paper chemicals according to claim 1, wherein the monomer component contains 20 to 95 mol% of acrylamides (a1) and 5 to 40 mol% of a cationic radically polymerizable monomer (a2). Claim 1 in which the water-soluble polymer (A) is a polymer of a monomer component (however, not containing metharylsulfonic acid and / or a salt thereof) further containing an anionic radically polymerizable monomer (a3). Or the dispersion liquid for papermaking chemicals according to 2. The dispersion for paper chemicals according to any one of claims 1 to 3, wherein the cationic radically polymerizable monomer (a2) has an amino group-containing (meth) acrylate group. The anionic radically polymerizable monomer (a3) (however, not containing metallyl sulfonic acid and / or a salt thereof) is at least one selected from the group consisting of acrylic acid, itaconic acid and itaconic anhydride. The dispersion liquid for papermaking chemicals according to claim 3. The dispersion liquid for paper chemicals according to any one of claims 1 to 5 , wherein the amount of the polymer dispersant (B) used is 1 to 10 parts by weight with respect to 100 parts by weight of the water-soluble polymer (A). The dispersion liquid for paper chemicals according to any one of claims 1 to 6 , wherein the polyhydric alcohol (C) has 2 to 10 carbon atoms. In the presence of the polymer dispersant (B) and the polyhydric alcohol (C) , the (meth) acrylamide (a1) and the cationic radically polymerizable monomer (a2) are contained in a salt aqueous solution having a saturation concentration or less. monomer components (but not including methallyl sulfonic acid and / or salts thereof) comprises the step of forming water-soluble polymer (a) by dispersion polymerization, and
The temperature of the step is 15 to 70 ° C.
A method for producing a dispersion liquid for paper chemicals , wherein the polymerization reaction rate in this step is 2 to 40% when 2 hours have passed from the start of addition of the polymerization initiator.
The amount of unreacted (meth) acrylamide (a1) in the water-soluble polymer (A) is 2000 ppm or less, and
The weight ratio of the agglomerates in the dispersion is 1% by weight or less, and
A method for producing a dispersion liquid for paper chemicals , wherein the intrinsic viscosity (temperature 25 ° C.) of the dispersion liquid in a 1N NaCl aqueous solution is 5 to 30 dl / g. The intrinsic viscosity (temperature 25 ° C.) of the reaction solution containing the components (A), (B) and (C) in the 1N NaCl aqueous solution 2 hours after the start of addition of the polymerization initiator is 0.5. The method for producing a dispersion liquid for paper-making chemicals according to claim 8 , which is ~ 12 dl / g. A paper strength enhancer containing the dispersion liquid for paper chemicals according to any one of claims 1 to 7. A papermaking drainage improving agent containing the dispersion liquid for papermaking chemicals according to any one of claims 1 to 7. A yield improver for papermaking containing the dispersion liquid for papermaking chemicals according to any one of claims 1 to 7.