WO2015098742A1

WO2015098742A1 - Method for producing paper

Info

Publication number: WO2015098742A1
Application number: PCT/JP2014/083688
Authority: WO
Inventors: 佐藤　茂
Original assignee: 栗田工業株式会社
Priority date: 2013-12-25
Filing date: 2014-12-19
Publication date: 2015-07-02
Also published as: JP5835314B2; JP2015124446A

Abstract

Provided is a method for producing paper with which it is possible to improve the yield and filterability of a filler. This method for producing paper comprises a step for making paper on wires from a paper material in which a pulp slurry and a filler-containing slurry including a water-soluble polymer are mixed. The water-soluble polymer includes: 100 parts by mass of a cationic polymer obtained by polymerizing monomer components including a cationic vinyl monomer represented by general formula (I) and a nonionic vinyl monomer copolymerizable with said cationic vinyl monomer; and 0.1-2 parts by mass of an anionic polymer that is obtained by polymerizing monomer components including 5-40 mol% of (meth)acrylic acid and/or sodium (meth)acrylate, and that has an intrinsic viscosity of 10 dl/g or greater in a 1 N NaCl aqueous solution at 30°C. The water-soluble polymer or the cationic polymer has an intrinsic viscosity of 8 dl/g or greater in a 1 N NaCl aqueous solution at 30°C. (In general formula (I): R¹ is H or CH₃; A is O or NH; R² is a C_2-4 alkyl group that may include a hydroxyl group as a substituent; R³ each independently represents H or a C_1-3 alkyl group; R⁴ is H, a C_1-3 alkyl group that may include a hydroxyl group as a substituent, or a benzyl group; and X^- is a halogen ion, a sulfonate ion, a methylsulfate ion, or a hydroxide ion.)

Description

Paper manufacturing method

This technology relates to a paper manufacturing method using a water-soluble polymer.

In the manufacture of paper, for the purpose of improving paper quality such as printability, strength, smoothness (texture), and whiteness of paper, fillers, sizing agents, and paper strength are added to the paper stock containing pulp. Addition of papermaking chemicals such as enhancers, yield improvers and freeness improvers has been performed.
In recent years, there is a tendency to use a large amount of filler for the purpose of reducing energy during paper production, saving pulp fibers, improving paper quality, and the like.

Also, paper production is generally performed by a paper machine equipped with a wire part, which is a process of making wet paper by pouring a moisture-rich stock over a net (wire) and flattening it thinly. Yes.
If the filler yield on the wire in the paper machine is low, the effect of improving the paper quality by adding the filler may be reduced. Further, in this case, the increase in filler passing through the wire may increase the wear of the wire, and may cause dirt in the raw material recovery circulation system, which may increase the burden of white water treatment. . Therefore, filler yield on paper machine wires is an important factor in papermaking.

For example, Patent Documents 1 and 2 disclose techniques for adding a cationic starch flocculant to a filler. However, as described in Patent Document 3, in the techniques disclosed in Patent Documents 1 and 2, the amount of the flocculant added is large, the size of the aggregated filler particles is not uniform, and the market share is weak. The yield rate may not be obtained with good reproducibility.
In Patent Document 3, for the purpose of improving filler yield and drainage, a water-soluble amphoteric polymer is added to a filler-containing slurry and pre-agglomerated, and the resulting pre-agglomerated filler slurry is mixed with pulp fiber slurry. However, a paper manufacturing method for forming a sheet on a wire has been proposed.

US Pat. No. 4,799,964 JP 2000-129589 A Japanese Patent Laid-Open No. 2005-194651

As described above, in view of the problems that can occur when the yield of filler on the paper machine wire in papermaking is low, further improvement in filler yield is required.

Therefore, the present invention intends to provide a paper manufacturing method in which the yield rate of the filler is improved in the paper making process.

That is, the present invention is a paper manufacturing method comprising a step of papermaking on a wire a paper stock mixed with a filler-containing slurry containing a water-soluble polymer and pulp slurry, the water-soluble polymer is the following general 100 parts by weight of a cationic polymer obtained by polymerizing a cationic vinyl monomer represented by the formula (I) and a monomer component containing a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer; Anionic polymer having an intrinsic viscosity of 10 dl / g or more in a 1N NaCl aqueous solution at 30 ° C. obtained by polymerizing a monomer component containing 5 to 40 mol% of acrylic acid and / or sodium (meth) acrylate 0.1 to 2 parts by mass of the water-soluble polymer or the cationic polymer in a 1N NaCl aqueous solution at 30 ° C. Provided is a paper manufacturing method having an intrinsic viscosity of 8 dl / g or more.

In the above general formula (I), R ¹ is H or CH ₃ , A is O or NH, R ² is an alkyl group having 2 to 4 carbon atoms which may have a hydroxyl group as a substituent. Each of R ³ is independently H or an alkyl group having 1 to 3 carbon atoms, and R ⁴ is H, an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group as a substituent, or A benzyl group, and X ⁻ is a halogen ion, a sulfonate ion, a methylsulfate ion, or a hydroxide ion.

The paper manufacturing method may include a step of pre-aggregating the filler-containing slurry containing the water-soluble polymer, and a step of mixing the pre-aggregated slurry and the pulp slurry.
The filler-containing slurry containing the water-soluble polymer contains 0.01 to 0.5 parts by mass of the water-soluble polymer with respect to 100 parts by mass of the solid content of the filler-containing slurry before the water-soluble polymer is added. Also good.
This paper manufacturing method may include a step of adding the cationic polymer and the anionic polymer to the filler-containing slurry to obtain a filler-containing slurry containing the water-soluble polymer.
The water-soluble polymer includes the anionic polymer, and a cationic polymer obtained by polymerizing the monomer component containing the cationic vinyl monomer and the nonionic vinyl monomer in a solution of the anionic polymer. , May be included.

In the present disclosure, the description “(meth) acryl” means both “acryl” and “methacryl”.
The paper produced in the present disclosure also includes paperboard.

According to the present invention, it is possible to provide a paper manufacturing method in which the filler yield is improved in the paper making process.

Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

The paper manufacturing method according to the embodiment of the present invention includes a step of papermaking on a wire a paper material in which a filler-containing slurry containing a water-soluble polymer and a pulp slurry are mixed.
First, the “water-soluble polymer”, “filler-containing slurry”, and “pulp slurry” used in the paper manufacturing method will be described.

<Water-soluble polymer>
The water-soluble polymer used in the present embodiment includes a cationic polymer and an anionic polymer, and may be a polymer mixture including these polymers.
This water-soluble polymer includes a cationic polymer obtained by copolymerizing a cationic vinyl monomer represented by the following general formula (I) and a nonionic vinyl monomer, and (meth) acrylic acid and / or (meth). And an anionic polymer obtained by polymerizing a monomer component containing 5 to 40 mol% of sodium acrylate. Here, the intrinsic viscosity of the anionic polymer in a 1N NaCl aqueous solution at 30 ° C. is 10 dl / g or more. The ratio of the cationic polymer to the anionic polymer is 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer.

As the water-soluble polymer, a polymer in which a cationic polymer and an anionic polymer are separately synthesized and mixed, and a polymer containing a cationic polymer synthesized in the solution are used in a solution of the anionic polymer. it can.
When a water-soluble polymer (polymer mixture) in which a cationic polymer and an anionic polymer are separately synthesized and mixed is used, a cationic polymer having an intrinsic viscosity of 8 dl / g or more in a 1N NaCl aqueous solution at 30 ° C. Is used (first aspect described later).
Further, when a water-soluble polymer containing a cationic polymer synthesized in the solution is used in the solution of the anionic polymer, the water-soluble polymer containing the cationic polymer and the anionic polymer is 30 ° C. A water-soluble polymer (polymer mixture) having an intrinsic viscosity of 8 dl / g or more in a 1N NaCl aqueous solution is used (second mode described later).

The water-soluble polymer according to the first aspect of the present embodiment is a monomer containing a cationic vinyl monomer represented by the following general formula (I) and a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer. 5 to 40 mol% of a cationic polymer obtained by polymerizing the components and having an intrinsic viscosity of 8 dl / g or more in a 1N NaCl aqueous solution at 30 ° C., and (meth) acrylic acid and / or sodium (meth) acrylate And an anionic polymer having an intrinsic viscosity of 10 dl / g or more in a 1N NaCl aqueous solution at 30 ° C.
The water-soluble polymer of this embodiment contains a cationic polymer and an anionic polymer at a ratio of 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer.

The cationic polymer is obtained by copolymerizing a monomer component containing a cationic vinyl monomer represented by the above general formula (I) and a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer. From this fact, this cationic polymer is composed of a structural unit derived from the cationic vinyl monomer represented by the general formula (I) in the molecule and a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer. It can be said that the copolymer has a derived structural unit.

As the cationic vinyl monomer constituting the monomer component that is a raw material of the cationic polymer, the compound represented by the above general formula (I) can be used.
In the general formula (I), R ¹ is more preferably H, and A is more preferably O. R ² is more preferably an alkyl group having 2 to 4 carbon atoms (having no substituent), and more preferably an ethyl group. R ³ is more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. R ⁴ is more preferably H or an alkyl group having 1 to 3 carbon atoms (having no substituent), and more preferably a methyl group. X ⁻ is more preferably a halogen ion, and even more preferably a chloride ion.

Examples of the cationic vinyl monomer represented by the general formula (I) include dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate, quaternary salts and acid salts thereof, and dialkylamino Mention may be made of alkyl (meth) acrylamides, quaternary salts and acid salts thereof.
Although it does not specifically limit as a (meth) acrylic-acid dialkylaminoalkyl and its quaternary salt and acid salt, For example, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl benzyl chloride quaternary salt, acrylic acid Examples thereof include dimethylaminoethyl hydrochloride, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, and dimethylaminoethyl methacrylate hydrochloride.
Dialkylaminoalkyl (meth) acrylamides and quaternary salts and acid salts thereof are not particularly limited, and examples thereof include acrylamidopropyltrimethylammonium chloride, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, and dimethylaminopropyl. Examples include methacrylamide hydrochloride.
One or two or more of these cationic vinyl monomers can be used.
As the cationic vinyl monomer, for example, a (meth) acrylic acid dialkylaminoalkyl quaternary salt is suitable. Among them, (meth) acrylic acid dimethylaminoethyl methyl chloride quaternary salt is preferred, and acryloyloxyethyltrimethylammonium chloride is preferred. Is more preferable.

The nonionic vinyl monomer constituting the monomer component that is a raw material of the cationic polymer is not particularly limited as long as it is copolymerizable with the cationic vinyl monomer.
Nonionic vinyl monomers include, for example, water-soluble substances such as (meth) acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N-methylolacrylamide, and diacetone acrylamide. Some N-substituted lower alkyl acrylamides, methacrylonitrile, acrylonitrile, alkyl acrylates, hydroxy acrylates, vinyl acetate, and the like. Among these, for example, (meth) acrylamide is preferable, and acrylamide is more preferable.
1 type (s) or 2 or more types can be used for a nonionic vinyl monomer.

The monomer component used as the raw material of the cationic polymer may contain a crosslinkable vinyl monomer in addition to the cationic vinyl monomer and the nonionic vinyl monomer.
The crosslinkable vinyl monomer brings a branched structure to the cationic polymer, and a monomer having two or more double bonds in one molecule can be used.

Typical preferred crosslinkable vinyl monomers include N, N-methylenebisacrylamide, N, N-methylenebismethacrylamide, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, triethylene glycol dimethacrylate. And polyethylene glycol dimethacrylate. Of these, N, N-methylenebisacrylamide is preferred.
These crosslinkable vinyl monomers may be used alone or in combination of two or more.

The production method of the cationic polymer is not particularly limited as long as it is radical polymerization, and can be selected as necessary, such as aqueous solution polymerization, suspension polymerization, and emulsion polymerization.

The polymerization initiator used in radical polymerization is not particularly limited, but is preferably water-soluble. Examples of the polymerization initiator include persulfate-based and peroxide-based compounds such as ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, benzoyl peroxide, and tert-butyl peroxide.
A polymerization initiator may be used individually by 1 type, or may use 2 or more types together, but it is preferable to use 1 type independently. A polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent. Examples of the reducing agent in this case include sulfites, sulfites and hydrogen sulfites, low-order ionic salts such as iron, copper, and cobalt, and organic amines such as N, N, N ′, N′-tetramethylethylenediamine. Furthermore, reducing sugars such as aldose and ketose can be mentioned.

An azo compound can also be used as a polymerization initiator. Examples of the azo compound include 2,2′-azobis-2-methylpropionamidine hydrochloride, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis-N, N′-di. Methyleneisobutylamidine hydrochloride, 2,2′-azobis-2-methyl-N- (2-hydroxyethyl) -propionamide, 2,2′-azobis-2- (2-imidazolin-2-yl) -propane and The salt etc. can be used. These azo compounds may be used alone or in combination of two or more.

In synthesizing the cationic polymer, a chain transfer agent may be used to adjust the molecular weight of the cationic polymer to be synthesized.
The chain transfer agent is not particularly limited, and examples of typical chain transfer agents include alcohols, sulfur compounds, carboxylic acids and salts thereof, phosphate phosphates such as sodium hypophosphite, and combinations thereof. Can be mentioned.
Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, butyl alcohol and glycerol. Of these, 2-propanol is preferable.
Examples of the sulfur compound include sulfonic acid compounds such as alkylthiol, thiourea, sulfite, and disulfide, and among these, one or more selected from the group consisting of ethanethiol, thiourea, and sodium bisulfite are included. preferable.
Examples of the carboxylic acid and its salt include formic acid, malic acid, and salts thereof, and among these, one or more selected from formic acid and its salt are preferable.
As these chain transfer agents, it is more preferable to use sodium hypophosphite and / or sodium formate.

Examples of the polymerization method of the cationic polymer include a batch polymerization method in which all monomer components as raw materials for the cationic polymer are charged in a reaction vessel at once and polymerized. At this time, the polymerization initiator may be added to the polymerization vessel in advance or at the time of polymerization, and may be supplied continuously or intermittently during the polymerization. When supplying at the time of superposition | polymerization, an addition rate can be changed as needed.
The polymerization temperature when synthesizing the cationic polymer is generally 30 to 100 ° C. when a single polymerization initiator is used, and is lower and generally 5 to 90 ° C. for a redox polymerization initiator. The polymerization temperature may be kept constant or varied during the polymerization, and cooling and heating can be performed as necessary.
The atmosphere in the polymerization vessel is not particularly limited, but it is preferable to substitute with an inert gas such as nitrogen gas in order to carry out the polymerization quickly.

The cationic polymer obtained by polymerizing the monomer component containing the cationic vinyl monomer represented by the above general formula (I) and the nonionic vinyl monomer has an intrinsic viscosity (hereinafter, referred to as 1N NaCl aqueous solution at 30 ° C.). It may be abbreviated as “intrinsic viscosity.”) Is 8 dl / g or more. When the intrinsic viscosity of the cationic polymer is 8 dl / g or more, the cationic polymer has a high molecular weight and a high cohesive force.
The upper limit of the intrinsic viscosity of the cationic polymer is not particularly limited, but is preferably about 20 dl / g or less in consideration of the cationic polymer that can be actually produced. The range of the intrinsic viscosity of the cationic polymer is preferably 8 to 20 dl / g, more preferably 9 to 20 dl / g, still more preferably 10 to 20 dl / g.

In the present disclosure, the “intrinsic viscosity” is a value calculated using a Huggins equation and a Mead-Fuoss equation from the measured value by measuring the flow time using a Cannon Fenceke viscometer. .

The cationic polymer is preferably water-soluble. The molecular structure of the cationic polymer may be either a linear structure or a branched structure.

The amount (content) of the cationic vinyl monomer in the monomer component used as the raw material for the cationic polymer is not particularly limited, but is preferably 5 to 50 mol%, more preferably 5 to 30 mol%, and more preferably 5 to 25 mol%. Is more preferable.
Further, the use amount (content) of the nonionic vinyl monomer in the monomer component as the raw material of the cationic polymer is not particularly limited, but is preferably 50 to 95 mol%, more preferably 70 to 95 mol%, and more preferably 75 to 95 mol% is more preferable.

The ratio of the cationic vinyl monomer and nonionic vinyl monomer used as the raw material for the cationic polymer can be arbitrarily selected according to the water quality to be treated. For example, the molar ratio of cationic vinyl monomer: nonionic vinyl monomer is preferably 5:95 to 95: 5, more preferably 5:95 to 50:50, and even more preferably 5:95 to 35:65.

When a crosslinkable vinyl monomer is used in the synthesis of the cationic polymer, the introduction ratio of the crosslinkable vinyl monomer is 5.0 × 10 5 with respect to all monomers of the monomer component that is the raw material of the cationic polymer. ⁻³ mol% or less is preferable, and 2.0 × 10 ⁻³ mol% or less is more preferable. When the introduction ratio of the crosslinkable vinyl monomer is within the above range, the cationic polymer is hardly insolubilized, and a cationic polymer having an intrinsic viscosity of 8 dl / g or more is easily obtained.

The water-soluble polymer of this embodiment includes an anionic polymer obtained by polymerizing a monomer component containing 5 to 40 mol% of (meth) acrylic acid and / or sodium (meth) acrylate together with a cationic polymer. From this, it can be said that an anionic polymer is a polymer or copolymer having a structural unit derived from (meth) acrylic acid and / or sodium (meth) acrylate.

In the anionic polymer obtained by including 5 to 40 mol% of (meth) acrylic acid and / or sodium (meth) acrylate in the monomer component as a raw material of the anionic polymer, It tends to have a good anionic group action. When the amount of (meth) acrylic acid and / or sodium (meth) acrylate is less than 5 mol%, it becomes difficult to have an anionic group action, and when it exceeds 40 mol%, the anionic property is too strong, so that it reacts with a cationic polymer. As a result, a complex is formed, and the effective concentration of the functional group of the cation and anion may be lowered. The monomer component that is a raw material for the anionic polymer preferably contains 10 to 40 mol% of (meth) acrylic acid and / or sodium (meth) acrylate, and preferably 10 to 30 mol% in all monomer components. More preferably.

In addition to (meth) acrylic acid and sodium (meth) acrylate, the monomer component used as the raw material for the anionic polymer may contain a nonionic monomer. The content of the nonionic monomer is not particularly limited, but is preferably 60 to 95 mol%, more preferably 70 to 90 mol%, based on all monomer components used as a raw material for the anionic polymer.

Nonionic monomers in this case include, for example, (meth) acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N-methylolacrylamide, and diacetone acrylamide. N-substituted lower alkyl acrylamide, etc.
These nonionic monomers can be used alone or in combination of two or more. Of these nonionic monomers, (meth) acrylamide is preferred.

In synthesizing an anionic polymer, it is possible to polymerize a monomer component as a raw material of the anionic polymer using the polymerization initiator described in the explanation of the cationic polymer.

The anionic polymer has an intrinsic viscosity of 10 dl / g or more in a 1 N NaCl aqueous solution at 30 ° C. By using an anionic polymer having an intrinsic viscosity of 10 dl / g or more, a synergistic effect with the cationic polymer can be easily obtained.
The upper limit of the intrinsic viscosity of the anionic polymer is not particularly limited, but it is preferably 30 dl / g or less in consideration of the anionic polymer that can be actually produced. The range of the intrinsic viscosity of the anionic polymer is preferably 10 to 30 dl / g, more preferably 10 to 25 dl / g, and further preferably 11 to 25 dl / g.

The water-soluble polymer used in the paper manufacturing method of the present embodiment includes a cationic polymer and an anionic polymer in a ratio of 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer. Since the cationic polymer and the anionic polymer are used together at this ratio, a synergistic effect is achieved by the combined use of the cationic polymer and the anionic polymer, and a precipitate (polyion) due to the reaction between the cationic polymer and the anionic polymer. Complex) becomes difficult to form, and as a result, the concentration of the active ingredient can be increased.

The range of the intrinsic viscosity of the additive for papermaking of the first aspect in which a cationic polymer and an anionic polymer are mixed is not particularly limited, but is preferably 8 to 20 dl / g.

The water-soluble polymer according to the first aspect includes, for example, a step of separately synthesizing the cationic polymer and the anionic polymer as described above, and 0.1 to 2 mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer. It can manufacture by performing the process of mixing a cationic polymer and an anionic polymer in the ratio of a part.

The mixing of the cationic polymer and the anionic polymer may be performed in the form (for example, powder, emulsion, liquid, etc.) when the cationic polymer and the anionic polymer are respectively synthesized. In addition, a solution may be prepared after mixing the cationic polymer and the anionic polymer, each polymer in each form is dissolved separately, and then each solution is mixed to form one solution, and the filler-containing slurry You may add to. In this case, the water-soluble polymer containing the cationic polymer and the anionic polymer preferably has an intrinsic viscosity of 8 dl / g or more in a 1N NaCl aqueous solution at 30 ° C., and is 8 dl / g to 20 dl / g. Is preferred.

Next, the water-soluble polymer according to the second aspect of the present embodiment will be described.
The water-soluble polymer of the second embodiment is one that includes a anionic polymer and a cationic polymer obtained by synthesizing a cationic polymer in a solution of an anionic polymer. In this water-soluble polymer, a cationic polymer and an anionic polymer are contained at a ratio of 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer. The water-soluble polymer has an intrinsic viscosity of 8 dl / g or more in a 1N NaCl aqueous solution at 30 ° C.

In the water-soluble polymer of the second aspect, polymerization initiation that can be used for the synthesis of a cationic vinyl monomer, a nonionic vinyl monomer, a cross-linkable vinyl monomer, and a cationic polymer as a monomer component that is a raw material of the cationic polymer The agent and the chain transfer agent are the same as those described in the description of the water-soluble polymer of the first aspect. The anionic polymer used for the water-soluble polymer of the second aspect is the same as the anionic polymer described in the description of the water-soluble polymer of the first aspect.

The upper limit of the intrinsic viscosity of the water-soluble polymer of the second aspect is not particularly limited, but is preferably 20 dl / g or less in consideration of actually producing the water-soluble polymer. The range of the intrinsic viscosity of the water-soluble polymer is preferably 8 to 20 dl / g, more preferably 9 to 20 dl / g, and further preferably 10 to 20 dl / g.

The solvent for preparing the anionic polymer solution is not particularly limited. For example, water can be used, and an aqueous solution obtained by diluting and dissolving the anionic polymer can be used as the anionic polymer solution. In this case, the concentration of the anionic polymer in the anionic polymer solution is not particularly limited, but is preferably 0.01 to 0.5% by mass, for example, 0.1 to 0.3% by mass. It is more preferable.

The water-soluble polymer of the second embodiment is a ratio of 0.1 to 2 parts by weight of anionic polymer with respect to 100 parts by weight of cationic polymer in the synthesis of the cationic polymer in a solution of anionic polymer, and It can be produced by a method of synthesizing a cationic polymer such that the intrinsic viscosity in a 1N NaCl aqueous solution at 30 ° C. is 8 dl / g or more. For example, it is possible to give the obtained water-soluble polymer a desired intrinsic viscosity by adjusting the addition amount of the polymerization initiator used when synthesizing the cationic polymer.

In the method for producing a water-soluble polymer according to the second aspect, since the cationic polymer is synthesized in the solution of the anionic polymer, the cationic polymer and the anionic polymer are mixed with the synthesis of the cationic polymer. Therefore, a water-soluble polymer can be produced with high efficiency.
Furthermore, by adopting the water-soluble polymer production method of the second aspect in the papermaking process, the production of the water-soluble polymer and the papermaking can be performed consistently, and the paper can also be produced efficiently. It becomes possible.

The above-mentioned water-soluble polymer contains 100 parts by weight of the cationic polymer and 0.1 to 2 parts by weight of the anionic polymer, thereby forming a moderately crosslinked structure (network structure) while maintaining water solubility. Conceivable. As a result, it is considered that the effect of capturing inorganic fine particles such as pulp fibers and calcium carbonate is improved, and it is considered that excellent yield and drainage are exhibited. Therefore, the water-soluble polymer is suitably used as a yield / drainage improver.

In addition, since the water-soluble polymer of this embodiment is excellent in the aggregation effect, for example, in order to reuse the pulp fiber contained in the white water, the water-soluble polymer is added to the white water to aggregate the pulp fiber. It can also be used for recovering purposes. At this time, the pulp fibers can be aggregated by adding, for example, about 1 to 2 ppm of a water-soluble polymer to the mass of white water.

<Filler-containing slurry>
The above-mentioned water-soluble polymer is added to the filler-containing slurry to prepare a filler-containing slurry containing the water-soluble polymer. The filler-containing slurry is a slurry containing a filler and water.

The filler contained in the filler-containing slurry is not particularly limited, and examples thereof include those generally used for papermaking. Examples of the inorganic compound filler include calcium carbonate, magnesium carbonate, barium carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, talc, titanium dioxide, zinc oxide, zinc stearate, clays (kaolin) , Calcined kaolin, deramikaolin), amorphous silica such as amorphous silicon dioxide and calcium silicate (commonly called white carbon), silica / calcium carbonate composite, silica / titanium dioxide composite, white clay, bentonite, diatomaceous earth, and Examples include calcium sulfate. Examples of the organic compound filler include fine hollow particles such as urea-formalin resin, polystyrene resin, phenol resin, (meth) acrylic resin, and acrylamide composite. A filler may be used individually by 1 type, or may be used in combination of 2 or more type.

The shape and particle diameter of the filler are not particularly limited and are appropriately selected according to the type of paper to be produced.
As the shape of the filler, for example, various shapes such as a spherical shape, a granular shape, a plate shape, a scale shape, a needle shape, a column shape, a spindle shape, and an amorphous shape can be used. Moreover, about the particle size of a filler, 100 micrometers or less are preferable at an average particle diameter, for example, 50 micrometers or less are more preferable, and 10 micrometers or less are more preferable. In the present disclosure, the average particle size refers to a particle size at which the cumulative volume distribution in the dry particle size distribution obtained by particle size distribution measurement using a laser diffraction particle size distribution measuring device is 50%.

When preparing the filler-containing slurry, the concentration of the solid content (dry filler mass) of the filler-containing slurry is not particularly limited. For example, depending on the type and properties of the paper to be manufactured in the range of 0.05 to 50% by mass Can be selected as appropriate.

Further, the “filler-containing slurry containing a water-soluble polymer” in which a water-soluble polymer is added to the filler-containing slurry is based on 100 parts by mass of the solid content (dry filler mass) of the filler-containing slurry before the water-soluble polymer is added. The water-soluble polymer is preferably contained in an amount of 0.01 to 0.5 parts by mass as its solid content. The content of the water-soluble polymer is more preferably 0.1 to 0.5 parts by mass, and further preferably 0.1 to 0.4 parts by mass. Even when the content ratio of the water-soluble polymer with respect to the filler-containing slurry is small as in the above range, the filler yield and drainage can be improved. Since the content of the water-soluble polymer can be suppressed to a small amount, it is possible to suppress the formation deterioration and the manufacturing cost of the manufactured paper product. In the filler-containing slurry containing the water-soluble polymer, the cationic polymer and the anionic polymer are contained at a ratio of 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer as described above. ing.

<Pulp slurry>
The pulp slurry mixed with the filler-containing slurry described above is a slurry containing pulp fibers (also simply referred to as “pulp” in the present disclosure) and water.
The pulp is appropriately selected depending on the type of paper to be produced, and mechanical pulp, chemical pulp, and semi-chemical pulp having both sides of mechanical pulp and chemical pulp can be used.
More specifically, examples of the pulp include softwood bleached pulp (NBKP), hardwood bleached pulp (LBKP), stone grand pulp (SGP), pressurized stone grand pulp (PGP), refiner ground pulp (RGP), and chemi. Grand Pulp (CGP), Thermo Grand Pulp (TGP), Crushed Wood Pulp (GP), Thermo Mechanical Pulp (TMP), Chemi Thermo Mechanical Pulp (CTMP), Refiner Mechanical Pulp (RMP), Deinking Pulp (DIP), and West Pulp (WP) etc. are mentioned. Among these pulps, one kind or two or more kinds can be used.

The pulp concentration of the pulp slurry is not particularly limited, but is preferably, for example, 0.1 to 5% by mass, more preferably 0.2 to 2% by mass, and further preferably 0.3 to 1.5% by mass on a dry mass basis. .

<Manufacturing process>
Next, the manufacturing process in the paper manufacturing method of the present embodiment and the additives other than the above-described water-soluble polymer, filler-containing slurry and pulp slurry will be described.

The paper manufacturing method of the present embodiment includes a step (paper making step) of making paper on a wire in a wire part of a paper machine by using a paper stock in which a filler-containing slurry containing a water-soluble polymer and a pulp slurry are mixed.
The wire part type of the paper machine is not particularly limited. For example, a long net type paper machine, a circular net type paper machine, a multi-layer type paper machine, and a twin wire type paper machine such as a gap former type and an on-top wire type Etc. can be used.

A paper machine generally includes a wet part having a stock inlet (paper outflow part), a wire part (dehydration part), a press part (squeezing / watering part), a dryer part (drying part), and the like. The In the paper making process using a paper machine, paper can be manufactured through the process of each part in the paper machine. More specifically, after the prepared stock is sent to the stock inlet, it is supplied to the wire part and dehydrated in the wire part to form a paper layer. The paper layer that has undergone the wire part process is further dehydrated by pressure in the press part and then dried in the dryer part to make paper. Normally, after passing through the dryer part process, finishing and processing are performed through the size press part (coating part), calendar (gloss part) and reel part (winding part) processes.

In the paper manufacturing method of this embodiment, the preparation process which adjusts and mix | blends the raw material used for papermaking may be provided before the papermaking process.
For example, the paper manufacturing method of this embodiment includes an addition step of adding a water-soluble polymer to the filler-containing slurry before the water-soluble polymer is added to obtain a filler-containing slurry containing the water-soluble polymer. Also good.
In addition, this paper manufacturing method may include a mixing step of obtaining a paper stock by mixing a filler-containing slurry containing a water-soluble polymer and a pulp slurry. Prior to this mixing step, it is preferable to include a pre-aggregation step of pre-aggregating a filler-containing slurry containing a water-soluble polymer, and this mixing step is a step of mixing the pre-agglomerated slurry and the pulp slurry. It is preferable.

In the addition step, the addition amount of the water-soluble polymer to 100 parts by mass of the solid content (dry filler mass) of the filler-containing slurry is preferably 0.01 to 0.5 parts by mass as the solid content of the water-soluble polymer. The amount is more preferably 1 to 0.5 parts by mass, and further preferably 0.1 to 0.4 parts by mass.
When the water-soluble polymer of the first aspect described above is used, the adding step is performed by adding a cationic polymer and an anionic polymer to the filler-containing slurry. Further, when the water-soluble polymer of the second aspect described above is used, the adding step is to add the anionic polymer solution containing the cationic polymer synthesized in the anionic polymer solution to the filler-containing slurry. Is done. At this time, in both the first aspect and the second aspect, the cationic polymer and the anionic polymer are in a ratio of 0.1 to 2 parts by mass of the anionic polymer with respect to 100 parts by mass of the cationic polymer as described above. Added.

The pre-aggregation step can be performed, for example, by applying shear by means such as stirring the filler-containing slurry. Stirring of the filler-containing slurry can be performed by, for example, a homogenizer, a stirring mill, a stirring wet pulverizer, a vibration mill, or the like.
By pre-aggregating a filler-containing slurry containing a water-soluble polymer to obtain a pre-aggregated slurry, it is possible to improve the formation, strength, and the like of the paper to be produced.

In the mixing step, the filler-containing slurry (or pre-agglomerated slurry) containing the water-soluble polymer and the pulp slurry are mixed in an amount of 0.5 to 50% by mass on a dry mass basis with respect to the dry mass of the pulp in the pulp slurry. It is preferable to mix so that it may become a ratio. The ratio of the filler to the dry mass of the pulp is more preferably 1 to 40% by mass, and further preferably 1 to 30% by mass. When the proportion of the filler is large, the whiteness and weight of the paper increase, and conversely, when the proportion of the filler is small, the flexibility and strength of the paper increase, so it is suitable for the type of paper to be manufactured and the desired properties. It is preferable to set it as the ratio of a filler.

In the preparation step, for example, beating raw materials (pulp), adding dyes, paper strength enhancers, sizing agents, yield improvers, antifoaming agents, slime control agents, and other papermaking chemicals. And a process such as dust removal and degassing of the paper material may be performed.

Examples of the paper strength enhancer include urea formaldehyde resin, melamine formaldehyde resin, polyamide polyamine epichlorohydrin, and polyvinylamine.
Examples of the sizing agent include rosin, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), and polyvinyl alcohol (PVA).
Examples of the yield improver include aluminum sulfate (sulfuric acid band), polyacrylamide, and starches.

The paper production method of the present embodiment described in detail above can improve the filler yield and drainage. The water-soluble polymer contains a cationic polymer and an anionic polymer in a specific ratio, so that the reaction between the cationic group and the anionic group partially occurs, but the polymer is not precipitated or precipitated due to the formation of a polyion complex. Therefore, it is considered that a loose network structure is formed while maintaining water solubility. When this water-soluble polymer is added to the filler-containing slurry, the formed network takes in the filler particles, and the filler particle surface is modified by the polymer, so that it reacts with the pulp fibers and has a high yield effect. It is thought that can be obtained. Such a network is not formed by the cationic starch flocculant as in Patent Documents 1 and 2 or the conventional anionic polymer flocculant. According to the paper manufacturing method of the present embodiment, by forming the network structure, paper can be manufactured with excellent filler yield and drainage even if the amount of water-soluble polymer used is small. It is thought that you can.

Note that the paper manufacturing method of the present embodiment can also have the following configuration.
(1) A paper manufacturing method comprising a step of making a paper on a wire containing a filler-containing slurry containing a water-soluble polymer and a pulp slurry, wherein the water-soluble polymer has the general formula (I And 100 parts by weight of a cationic polymer obtained by polymerizing a monomer component containing a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer, and (meth) acrylic acid And / or an anionic polymer having an intrinsic viscosity of 10 dl / g or more in a 1N NaCl aqueous solution at 30 ° C. obtained by polymerizing a monomer component containing 5 to 40 mol% of sodium (meth) acrylate. And the intrinsic viscosity of the water-soluble polymer or the cationic polymer in a 1N NaCl aqueous solution at 30 ° C. is 8 A method for producing paper, which is dl / g or more.
(2) The method for producing paper according to (1), comprising: a step of pre-aggregating the filler-containing slurry containing the water-soluble polymer; and a step of mixing the pre-aggregated slurry and the pulp slurry. .
(3) The filler-containing slurry containing the water-soluble polymer is 0.01 to 0.5 parts by mass of the water-soluble polymer with respect to 100 parts by mass of the solid content of the filler-containing slurry before the water-soluble polymer is added. A method for producing paper as described in (1) or (2) above.
(4) Any one of the above (1) to (3), comprising a step of adding the cationic polymer and the anionic polymer to a filler-containing slurry to obtain a filler-containing slurry containing the water-soluble polymer. The paper manufacturing method as described in one.
(5) The water-soluble polymer is a cationic polymer obtained by polymerizing the anionic polymer and a monomer component containing the cationic vinyl monomer and the nonionic vinyl monomer in a solution of the anionic polymer. The method for producing paper according to any one of (1) to (4) above, comprising:

Hereinafter, the effects of the paper manufacturing method of this embodiment will be described with reference to test examples.

An anionic polymer obtained by polymerizing a monomer component containing a predetermined amount of sodium acrylate and acrylamide was used. As the anionic polymer, four types having different monomer component compositions and different intrinsic viscosities in a 1N NaCl aqueous solution at 30 ° C. were used. The composition and intrinsic viscosity of the anionic polymer used are shown in Table 1. Hereinafter, the used anionic polymer is shown using a sample number (No.) shown in Table 1. In Table 1, “NaA” represents sodium acrylate, and “AAm” represents acrylamide.

<Production Example 1>
10.9 g of 80% by weight aqueous solution of acryloyloxyethyltrimethylammonium chloride (hereinafter abbreviated as “DAA”, molecular weight 193.5), powdered acrylamide (hereinafter abbreviated as “AAm”) in 0.1% by weight aqueous solution of anionic polymer A1 , Molecular weight 71) 18.5 g, and 2.5 ml of a 0.009 mass% aqueous solution of N, N′-methylenebisacrylamide (hereinafter abbreviated as “MBA”, molecular weight 140) were mixed, and finally 0.1 of A1 The whole was made up to 100 ml with a% aqueous solution. The aqueous solution was put into a 300 ml separable flask equipped with a cooling tube, a nitrogen introduction tube, and a thermometer, and after nitrogen bubbling, 1 ml of an aqueous solution of potassium persulfate (hereinafter abbreviated as “KPS”) prepared to 1.36% by mass was added. Then, the polymerization was carried out for 12 hours by heating to 40 ° C.
A part of the obtained polymer gel was precipitated with acetone, and the solid concentration determined by vacuum drying the precipitate was 26.6% by mass, and the polymerization rate was 99.3%. The intrinsic viscosity of this polymer mixture was 12.9 dl / g. The sample name of this polymer mixture is “DA1”.
The composition ratio of the cationic polymer is DAA / AAm / MBA = 15/85/5 × 10 ⁻⁴ (mol%), and the ratio of the anionic polymer A1 to the cationic polymer is 0.373 mass% (cation A1 is 0.373 parts by mass with respect to 100 parts by mass of the conductive polymer. In this composition ratio of the cationic polymer, the MBA ratio was very small compared to DAA and AAm, so it was described as mol% with respect to the total of DAA and AAm, and the descriptions in Tables 2 and 3 below were also the same.

<Production Example 2>
Synthesis was performed under the same conditions as in Production Example 1 except that the anionic polymer A1 in Production Example 1 was changed to Anionic Polymer A2, and a polymer mixture was obtained. The solid matter concentration was 26.9% by mass, the polymerization rate was 100.2%, and the intrinsic viscosity was 11.6 dl / g. The sample name of this polymer mixture is “DA2”.
In this polymer mixture, the ratio of the anionic polymer A2 to the cationic polymer was 0.373% by mass (A2 is 0.373 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 3>
Synthesis was carried out under the same conditions as in Production Example 1 except that MBA was not used to obtain a polymer mixture. The solid concentration was 27.1% by mass, the polymerization rate was 101.8%, and the intrinsic viscosity was 11.3 dl / g. The sample name of this polymer mixture is “DA3”.
In this polymer mixture, the ratio of the anionic polymer A1 to the cationic polymer was 0.373% by mass (A1 is 0.373 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 4>
The anionic polymer A1 in Production Example 1 is an anionic polymer A2, and the ratio of the anionic polymer A2 to the cationic polymer is 2.0% by mass (A2 is 2.0 parts by mass with respect to 100 parts by mass of the cationic polymer). Except that, synthesis was performed under the same conditions as in Production Example 1 to obtain a polymer mixture. The solid concentration was 27.5% by mass, the polymerization rate was 100.1%, and the intrinsic viscosity was 13.0 dl / g. The sample name of this polymer mixture is “DA4”.

<Production Example 5>
Synthesis was performed under the same conditions as in Production Example 1 except that anionic polymer A3 was used instead of anionic polymer A1 in Production Example 1 to obtain a polymer mixture. The solid matter concentration was 26.7% by mass, the polymerization rate was 99.6%, and the intrinsic viscosity was 10.8 dl / g. The sample name of this polymer mixture is “DA5”.
In this polymer mixture, the ratio of the anionic polymer A3 to the cationic polymer was 0.373% by mass (A2 is 0.373 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 6>
Synthesis was performed under the same conditions as in Production Example 1 except that 1 ml of the KPS aqueous solution added in Production Example 1 was changed to 10 ml to obtain a polymer mixture. The solid concentration was 26.9% by mass, the polymerization rate was 100.4%, and the intrinsic viscosity was 6.9 dl / g. The sample name of this polymer mixture is “DA6”.
In this polymer mixture, the ratio of the anionic polymer A1 to the cationic polymer was 0.373% by mass (A1 is 0.373 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 7>
Using 10.9 g of an 80% by weight aqueous solution of DAA, 18.1 g of AAm, 2.5 ml of a 0.009% by weight aqueous solution of MBA and 1 ml of an aqueous solution of 1.36% by weight KPS, these were mixed and made up to 100 ml While stirring, 2.5 g of the anionic polymer A2 powder was dissolved in the mixture, and after bubbling with nitrogen, the mixture was heated to 40 ° C. and polymerized for 12 hours. Instruments and basic operations were performed under the same conditions as in Production Example 1. The solid concentration was 26.1% by mass, the polymerization rate was 97.4%, and the intrinsic viscosity was 9.8 dl / g. The sample name of this polymer mixture is “DA7”.
In this polymer mixture, the ratio of the anionic polymer A2 to the cationic polymer was 2.5% by mass (A2 was 2.5 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 8>
Synthesis was performed under the same conditions as in Production Example 1 except that the concentration of the aqueous solution of the anionic polymer A1 in Production Example 1 was changed to 0.05% by mass to obtain a polymer mixture. The solid concentration was 27.0% by mass, the polymerization rate was 100.7% by mass, and the intrinsic viscosity was 10.6 dl / g. The sample name of this polymer mixture is “DA8”.
In this polymer mixture, the ratio of the anionic polymer A1 to the cationic polymer was 0.05% by mass (A1 is 0.05 part by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 9>
Synthesis was carried out under the same conditions as in Production Example 1 except that the anionic polymer A1 in Production Example 1 was changed to Anionic Polymer A4 to obtain a polymer mixture. The solid concentration was 27.1% by mass, the polymerization rate was 101.1%, and the intrinsic viscosity was 8.1 dl / g. The sample name of this polymer mixture is “DA9”.
In this polymer mixture, the ratio of the anionic polymer A4 to the cationic polymer was 0.373% by mass (A4 is 0.373 parts by mass with respect to 100 parts by mass of the cationic polymer).

<Production Example 10>
Synthesis was carried out under the same conditions as in Production Example 1 except that the anionic polymer and MBA were not used to obtain a cationic polymer. The solid concentration was 26.9% by mass, the polymerization rate was 100.4%, and the intrinsic viscosity was 13.4 dl / g. The sample name of this cationic polymer is “D1”.

<Production Example 11>
Synthesis was carried out under the same conditions as in Production Example 1 except that the anionic polymer was not used, and a cationic polymer was obtained. The solid matter concentration was 26.8% by mass, the polymerization rate was 100.0%, and the intrinsic viscosity was 11.8 dl / g. The sample name of this cationic polymer is “D2”.

<Production Example 12>
In addition to changing the addition amount 1 ml of the KPS aqueous solution in Production Example 1 to 10 ml and using no anionic polymer, synthesis was performed under the same conditions as Production Example 1 to obtain a cationic polymer. The solid concentration was 26.7% by mass, the polymerization rate was 99.6%, and the intrinsic viscosity was 7.4 dl / g. The sample name of this cationic polymer is “D3”.

Table 2 shows a sample list of each manufacturing example described above.

<Drainage test>
A drainage test was carried out using each polymer produced in the production example. The water-soluble polymer used in each test example will be described later.
In the drainage test, newspaper waste paper beaten to 450 ml of Canadian Standard Freeness (CSF) was added so that the dry mass was 0.6% by mass, and then light calcium carbonate (brilliant 1500 manufactured by Shiraishi Kogyo Co., Ltd.) was added. ) Was added to 40% by mass with respect to the absolute dry paper stock.
Take 180 ml of pulp slurry in a 300 ml capacity poly beaker, add 0.1% by weight aqueous solution of “additive” used in each test example described later, and use a stirrer equipped with turbine blades at 250 rpm for 20 minutes. Stir for 2 seconds. Next, a metal cylinder having an inner diameter of 50 mm is placed on a Nutsche fune laid with a nylon filter cloth, and the aggregated pulp slurry is poured into the cylinder, and the amount of filtrate after 10 seconds is measured using a graduated cylinder. Further, the wet paper remaining on the filter cloth is taken on a polyester filter cloth and pressed for 60 seconds under a pressure of 3.0 kg / cm ² , and the moisture content of the wet paper after pressing is measured.

<Test Examples 1 to 4>
In Test Example 1, a drainage test of pulp slurry was performed using the polymer mixture “DA1” as an additive.
In Test Example 2, a drainage test of pulp slurry was performed using the polymer mixture “DA2” as an additive.
In Test Example 3, a drainage test of pulp slurry was performed using the polymer mixture “DA3” as an additive.
In Test Example 4, the drainage test of pulp slurry was performed using the polymer mixture “DA4” as an additive.

<Test Examples 5 to 7>
In Test Example 5, a cationic polymer D1 and a polymer mixture obtained by blending 1.0 part by weight of anionic polymer A1 with respect to 100 parts by weight of D1 (1.0% by weight of A1 with respect to D1) are additives. The drainage test of the pulp slurry was conducted.
In Test Example 6, a cationic polymer D2 and a polymer mixture obtained by blending 0.4 part by weight of anionic polymer A2 with respect to 100 parts by weight of D2 (0.4% by weight of A2 with respect to D2) are additives. The drainage test of the pulp slurry was conducted.
In Test Example 7, a cationic polymer D2 and a polymer mixture obtained by blending 0.1 part by weight of anionic polymer A1 with respect to 100 parts by weight of D2 (0.1% by weight of A1 with respect to D2) as an additive The drainage test of the pulp slurry was conducted.

<Comparative Test Examples 1 to 4>
In Comparative Test Example 1, the polymer mixture “DA5” was added. In Comparative Test Example 2, the polymer mixture “DA6” was added. In Comparative Test Example 3, the polymer mixture “DA7” was added. In Comparative Test Example 4, the polymer mixture “DA8” was added. A drainage test of pulp slurry was performed as an agent.

<Comparative Test Examples 5 and 6>
In Comparative Test Example 5, a cationic polymer “D1” was used as an additive and in Comparative Test Example 6 a cationic polymer “D2” was used as an additive, and a drainage test of pulp slurry was performed.

<Comparative Test Examples 7 and 8>
In Comparative Test Example 7, the cationic polymer “D1” and 0.5 part by mass of the anionic polymer “A3” (0.5% by mass of A3 with respect to D1) were blended with 100 parts by mass of D1. A drainage test of the pulp slurry was performed using the polymer mixture as an additive.
In Comparative Test Example 8, the cationic polymer “D3” and 0.5 part by mass of the anionic polymer “A1” (0.5% by mass of A1 with respect to D3) were blended with 100 parts by mass of D3. A drainage test of the pulp slurry was performed using the polymer mixture as an additive.

<Comparative Test Examples 9 and 10>
In Comparative Test Example 9, the cationic polymer “D2” and 2.5 parts by mass of the anionic polymer “A1” (2.5% by mass of A1 with respect to D2) were blended with 100 parts by mass of D2. A drainage test of the pulp slurry was performed using the polymer mixture as an additive.
In Comparative Test Example 10, the cationic polymer “D2” and 0.08 parts by mass of the anionic polymer “A1” (0.08% by mass of A1 with respect to D2) were blended with 100 parts by mass of D2. A drainage test of the pulp slurry was performed using the polymer mixture as an additive.

<Comparative Test Example 11>
In Comparative Test Example 11, a drainage test of pulp slurry was performed using the polymer mixture “DA9” as an additive.

Table 3 shows a list of test conditions for each test example, and Table 4 shows the results of each test.

In Test Examples 1 to 7, it was confirmed that the amount of filtrate after 10 seconds was larger than that of Comparative Test Examples 1 to 11, and the moisture content after pressing was low. As a result, it was confirmed that the water-soluble polymers of Test Examples 1 to 6 can improve the drainage even with a small addition amount. Therefore, it is considered that by using the water-soluble polymers of Test Examples 1 to 6 when making paper, it is possible to suppress a decrease in the formation of paper products and manufacturing costs.

<Yield test>
Next, according to the following examples and comparative examples, a yield test was performed using each polymer produced in the production example.

(Examples 1 to 7)
DIP, NBKP, and TMP pulp samples and white water from the actual machine are collected from the paper mill and adjusted to DIP 60% by mass, NBKP 10% by mass, TMP 30% by mass (all based on dry mass, the same applies hereinafter), and pulp slurry It was. This is the paper stock (A). The pulp slurry concentration of the stock (A) was 0.65% by mass.

Next, white carbon (trade name: Toku Seal (registered trademark) GU-N manufactured by Tokuyama Corporation) was used as a filler, and 0.1% by mass of the water-soluble polymer produced in the production example was added to white carbon. Thereafter, shear force was applied with a stirrer under conditions of 800 rpm for 10 seconds to prepare a pre-aggregated filler slurry. This is the paper stock (B). The filler concentration in water of the stock (B) was 0.11% by mass (for the stock B).
As the water-soluble polymer, “DA1” in Example 1, “DA2” in Example 2, “DA3” in Example 3, and “DA4” in Example 4 were used. Example 5 is a combination of 100 parts by weight of “D1” and 1 part by weight of “A1”, and Example 6 is a combination of 100 parts by weight of “D2” and 0.4 parts by weight of “A2”. In No. 7, a combination of 100 parts by mass of “D2” and 0.1 part by mass of “A1” was used.

Subsequently, the stock (A) was put into a drainage yield tester DFS (Dynamic Filtration System) manufactured by Mutec Co., Ltd., and a sulfuric acid band was added to 3.5% by weight of dry pulp and a sizing agent (Starlight PMC). Co., Ltd. trade name: AL120) with 0.2% by weight of dry pulp, paper strength agent (trade name: EX230 made by Harima Chemicals Group Co., Ltd.) with 0.3% by weight of dry pulp, and the above-mentioned paper (B ) Are added in this order so that the white carbon is 4% by weight with respect to the dry pulp, and a cationic retention agent (trade name: High Holder (registered trademark) 220 manufactured by Kurita Kogyo Co., Ltd.) is added to the dry pulp 0. 015% by mass was added, and the filtrate (C) was collected. The DFS setting conditions followed the recommendations of Mutek.

The concentration of filler in the collected filtrate (C) (the filler content was determined according to ash content measurement method ISO 1762-1974) was measured, and the filler yield was calculated according to the following formula. The results are shown in Table 5.
SS FPR = [1−SS concentration of filtrate (C) / SS concentration of stock (B)] × 100 (%)
(SS: Suspended Solid, FPR: First Yield Rate)
-FPAR of filler = [1-ash concentration of filtrate (C) / ash concentration of paper (B)] x 100 (%)
(FPAR: First Ash Ash Retention)
The SS concentration of the stock (B) and the ash concentration of the stock (B) are the SS concentration and the ash concentration of the stock (B) in the inlet, respectively, and these are also shown in Table 5.

(Comparative Examples 1 to 15)
In Comparative Example 1, the stock (B) used in the example was a stock (B) to which the water-soluble polymer produced in the production example was not added, and the cationic retention agent used in the example was added. A test similar to the example was performed except that it was not performed.
In Comparative Example 2, the same test as in the Example was performed except that the stock (B) used in the example was a stock (B) to which the water-soluble polymer produced in the production example was not added.
In Comparative Example 3, the same test as in the Example was performed except that the water-soluble polymer in the stock (B) used in the Example was changed to cationized starch (trade name: Cato302 manufactured by Nippon SC Co., Ltd.). It was.
In Comparative Example 4, the water-soluble polymer in the stock (B) used in the example was changed to a cationic retention agent (trade name: High Holder 220 manufactured by Kurita Kogyo Co., Ltd.), and was the same as in the example. A test was conducted.
In Comparative Examples 5 to 15, the same tests as in the Examples were performed except that the water-soluble polymer in the stock (B) used in the Examples was changed to a water-soluble polymer outside the scope of the present invention. Specifically, “DA5” in Comparative Example 5, “DA6” in Comparative Example 6, “DA7” in Comparative Example 7, “DA8” in Comparative Example 8, “D1” in Comparative Example 9, and “DA1” in Comparative Example 10 D2 "and Comparative Example 15 used" DA8 ".
In Comparative Example 11, a combination of 100 parts by weight of “D1” and 0.5 parts by weight of “A3”, in Comparative Example 12, a combination of 100 parts by weight of “D3” and 0.5 parts by weight of “A1”, In Comparative Example 13, a combination of 100 parts by weight of “D2” and 2.5 parts by weight of “A1”. In Comparative Example 14, a combination of 100 parts by weight of “D2” and 0.08 parts by weight of “A1”. In Comparative Example 15, “DA9” was used.
The results of Comparative Examples 1 to 15 are also shown in Table 5.

(Examples 8 to 14)
DIP, NBKP, LBKP pulp samples and white water from the actual machine are collected from the paper mill, adjusted to DIP 20% by mass, NBKP 10% by mass, LBKP 70% by mass (all based on dry mass, the same applies hereinafter), and pulp fiber A slurry was obtained. This is the paper stock (D). The pulp fiber concentration of the stock (A) was 0.93% by mass.

Next, clay (trade name: KAOGLOSS, manufactured by Shiraishi Calcium Co., Ltd.) is used as a filler, and 0.4% by mass of the water-soluble polymer produced in the production example is added to the clay, and then subjected to conditions of 800 rpm for 40 seconds. Then, a shear force was applied with a stirrer to prepare a pre-aggregated filler slurry. This is the paper stock (E). The filler concentration in water of the stock (E) was 0.19% by mass.
As the water-soluble polymer, “DA1” in Example 8, “DA2” in Example 9, “DA3” in Example 10, and “DA4” in Example 11 were used. In Example 12, a combination of 100 parts by weight of “D1” and 1.0 part by weight of “A1”; in Example 13, a combination of 100 parts by weight of “D2” and 0.4 parts by weight of “A2”; In Example 14, a combination of 100 parts by mass of “D2” and 0.1 part by mass of “A1” was used.

Subsequently, the stock (D) was put into a drainage yield tester DFS (Dynamic Filtration System) manufactured by Mutec Co., Ltd., and the sulfate band was 4% by mass with respect to dry pulp, cationized starch (Nihon SC). Co., Ltd. trade name: Cato302) for dry pulp 0.8% by weight, AKD (alkyl ketene dimer) for dry pulp 0.1% by weight, sizing agent (trade name: AS262 made by Seiko PMC Co., Ltd.) 0.1% by mass of dry pulp, and the above-mentioned stock (E) were added in this order so that the clay was 6% by mass of dry pulp, and a cationic retention agent (trade name: manufactured by Kurita Kogyo Co., Ltd .: High Holder (registered trademark) 220) with 0.02% by weight of dry pulp and bentonite (trade name: Organoso, manufactured by Ciba Specialty Chemicals) rb O) was added to 0.1% by weight of dry pulp, and the filtrate (F) was collected. The DFS setting conditions followed the recommendations of Mutek.

The concentration of the filler in the collected filtrate (F) (the filler content is in accordance with ash measurement method ISO 1762-1974) was measured, and the filler yield was calculated according to the following formula. The results are shown in Table 6.
SS FPR = [1−SS concentration of filtrate (F) / SS concentration of stock (E)] × 100 (%)
(SS: Suspended Solid, FPR: First Yield Rate)
・ FPAR of filler = [1−ash content of filtrate (F) / ash content of paper (E)] × 100 (%)
(FPAR: First Ash Ash Retention)
The SS concentration of the stock (E) and the ash concentration of the stock (E) are the SS concentration and the ash concentration of the stock (E) in the inlet, respectively, and these are also shown in Table 6.

(Comparative Examples 16 to 30)
In Comparative Example 16, the stock (E) used in Examples 8 to 14 was the stock (E) to which the water-soluble polymer produced in Production Example was not added, and the cation used in Examples 8 to 14 The same tests as in Examples 8 to 14 were conducted except that no sex retention agent was added.
In Comparative Example 17, the stock (E) used in Examples 8 to 14 was the same as Example 8 to 14 except that the stock (E) to which the water-soluble polymer produced in the production example was not added was used. A test was conducted.
In Comparative Example 18, Examples 8 to 14 were used except that the water-soluble polymer in the stock (E) used in Examples 8 to 14 was changed to cationized starch (trade name: Cato 302 manufactured by NSC Japan). The same test was conducted.
In Comparative Example 19, the water-soluble polymer in the stock (E) used in Examples 8 to 14 was changed to a cationic retention agent (trade name: High Holder 220 manufactured by Kurita Kogyo Co., Ltd.). Tests similar to 8-14 were conducted.
In Comparative Examples 20 to 30, tests similar to those in Examples 8 to 14 except that the water-soluble polymer in the stock (E) used in Examples 8 to 14 was changed to a water-soluble polymer outside the scope of the present invention. Went. Specifically, the comparative example 20 is “DA5”, the comparative example 21 is “DA6”, the comparative example 22 is “DA7”, the comparative example 23 is “DA8”, the comparative example 24 is “D1”, and the comparative example 25 is “ D2 "was used respectively. In Comparative Example 26, a combination of 100 parts by weight of “D1” and 0.5 parts by weight of “A3”, in Comparative Example 27, a combination of 100 parts by weight of “D3” and 0.5 parts by weight of “A1”, In Comparative Example 28, a combination of 100 parts by weight of “D2” and 2.5 parts by weight of “A1”. In Comparative Example 29, a combination of 100 parts by weight of “D2” and 0.08 parts by weight of “A1”. In Comparative Example 30, “DA9” was used.
The results of Comparative Examples 16 to 30 are also shown in Table 6.

From the above results, it was confirmed that when the water-soluble polymer used in Examples 1 to 14 was added to the filler-containing slurry, an excellent yield was obtained as compared with Comparative Examples 1 to 30.
As a result, it was confirmed that the yield rate and the drainage of the filler can be improved by using a water-soluble polymer containing a specific amount of the above-mentioned cationic polymer and the above-mentioned anionic polymer as a papermaking additive in the papermaking process. It was done.

Claims

A paper manufacturing method comprising a step of making a paper on a wire containing a filler-containing slurry containing a water-soluble polymer and a pulp slurry,
The water-soluble polymer is
100 parts by weight of a cationic polymer obtained by polymerizing a cationic vinyl monomer represented by the following general formula (I) and a monomer component containing a nonionic vinyl monomer copolymerizable with the cationic vinyl monomer;
An anion having an intrinsic viscosity of 10 dl / g or more in a 1N NaCl aqueous solution at 30 ° C. obtained by polymerizing a monomer component containing 5 to 40 mol% of (meth) acrylic acid and / or sodium (meth) acrylate 0.1 to 2 parts by weight of a functional polymer,
Intrinsic viscosity of the water-soluble polymer or the cationic polymer in a 1N NaCl aqueous solution at 30 ° C. is 8 dl / g or more,
Paper manufacturing method.

(In the above general formula (I), R 1 is H or CH 3 , A is O or NH, and R 2 is an alkyl group having 2 to 4 carbon atoms which may have a hydroxyl group as a substituent. Each of R 3 is independently H or an alkyl group having 1 to 3 carbon atoms, R 4 is H, an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group as a substituent, Or a benzyl group, and X − represents a halogen ion, a sulfonate ion, a methylsulfate ion, or a hydroxide ion.)
Pre-aggregating a filler-containing slurry containing the water-soluble polymer;
Mixing the pre-agglomerated slurry and the pulp slurry;
A paper manufacturing method according to claim 1.
The filler-containing slurry containing the water-soluble polymer contains 0.01 to 0.5 parts by mass of the water-soluble polymer with respect to 100 parts by mass of the solid content of the filler-containing slurry before the water-soluble polymer is added. Item 3. A method for producing paper according to Item 1 or 2.
The paper production according to any one of claims 1 to 3, comprising a step of adding the cationic polymer and the anionic polymer to a filler-containing slurry to obtain a filler-containing slurry containing the water-soluble polymer. Method.
The water-soluble polymer includes the anionic polymer and a cationic polymer obtained by polymerizing the monomer component containing the cationic vinyl monomer and the nonionic vinyl monomer in a solution of the anionic polymer. The method for producing paper according to any one of claims 1 to 4, which is a waste product.