JP2001140192A - Method for fixing size - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, when a cationic size fixing agent is added to a papermaking raw material in which a fluorescent dye and a sizing agent coexist, the fluorescent dye and the size fixing agent have an interaction and the effect of the fluorescent dye is extremely reduced. SOLUTION: A sizing degree can be improved without lowering the effect of the fluorescent dye by adding a diallylamine-based polymer as the size fixing agent to a papermaking raw material before a total yield improver or a loading material yield improver is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a size fixing method, and more particularly, to a size fixing method characterized by adding a specific polymer to a papermaking raw material in which a fluorescent dye and a sizing agent coexist to form a paper. About the method.

[0002]

2. Description of the Related Art When making paper to be subjected to sizing, in order to enhance the effect of the added sizing agent, a size fixing agent is added to the papermaking system separately from the filler retention improver or the total retention enhancer. It is often added. Low size fixer
A cationic polymer having a moderate degree of polymerization is added. Conventionally, these cationic polymers have been used as a Hoffman reaction product of polyacrylamide as an acidic size fixing agent (JP-A-53-1).
4807), weakly acidic to slightly alkaline size (pH 5.5)
(Paper making: 7.5 to 7.5) Vinylamine-based polymers (JP-A-4-11094) have been filed as fixing agents. In addition, (co) polymers of acrylic cations are generally widely used at papermaking pH in the acidic to neutral range.

On the other hand, at present, in most cases, a fluorescent dye is added to papermaking raw materials in order to standardize the color tone of commercialized paper. Therefore, the problem here is the interaction between the fluorescent dye and the cationic polymer added as the size fixing agent. A polyallylamine-based polymer, a polyvinylamine-based polymer, a polyamidine-based polymer, and the like have a certain or more function as a size fixing action, but have a very strong effect on a fluorescent dye. As a result, the effect of the added fluorescent dye is reduced, and the paper darkens or turns yellow. In addition, the acrylic cationic polymer most commonly used has less influence on the fluorescent dye than the primary amino group-containing polymer, but the effect cannot be ignored.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for improving the sizing degree by adding a size fixing agent to a papermaking raw material in which a fluorescent dye and a sizing agent coexist, without affecting the coexisting fluorescent dye. An object of the present invention is to provide a size fixing method that improves the effect.

[0005]

Means for Solving the Problems The present invention has been studied in detail in order to solve the above-mentioned problems, and as a result, it has been found that by adding a diallylamine-based polymer to a papermaking raw material in which a fluorescent dye and a sizing agent coexist, papermaking is performed. Have discovered that it is possible to improve the size effect without lowering the function of the fluorescent dye, and have completed the present invention.

The invention of claim 1 relates to a size fixing method characterized by adding a diallylamine-based polymer to a papermaking raw material to perform papermaking.

According to a second aspect of the present invention, the size fixing method according to the first aspect, wherein the diallylamine-based polymer is a copolymer of a diallylamine and another vinyl monomer copolymerizable with the diallylamine. It is.

[0008] The invention of claim 3 is characterized in that the diallylamine-based polymer is a copolymer of 5 to 50 mol% of diallyldimethylammonium salt and another vinyl monomer copolymerizable therewith. 3. The size fixing method according to 1 or 2.

The invention of claim 4 is characterized in that the diallylamine-based polymer is a copolymer of diallyldimethylammonium chloride of 5 to 50 mol% and acrylamide of 50 to 95 mol%. The size fixing method according to any one of the above.

The invention of claim 5 is characterized in that the diallylamine-based polymer is a copolymer of 5 to 30 mol% of diallyldimethylammonium chloride and 70 to 95 mol% of acrylamide. The size fixing method according to any one of the above.

The invention according to claim 6 is the size fixing method according to any one of claims 1 to 5, wherein the molecular weight of the diallylamine-based polymer is from 100,000 to 5,000,000.

[0012] The invention of claim 7 is the size fixing method according to any one of claims 1 to 6, wherein a fluorescent dye coexists in the papermaking raw material.

The invention according to claim 8 is the size fixing method according to claim 7, wherein the fluorescent dye is anionic.

The invention of claim 9 is the size fixing method according to any one of claims 1 to 8, wherein the sizing agent is a rosin sizing agent.

According to a tenth aspect of the present invention, the size according to any one of the first to ninth aspects, wherein the diallylamine-based polymer is added before the addition of the total retention aid or the filler retention aid. This is the fixing method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the diallylamine-based monomer used for producing the diallylamine-type polymer used in the present invention include salts with an organic acid or an inorganic acid such as diallylamine and diallylmethylamine, or triarylamine. There are quaternary ammonium salts of lower dialkyl monoalkylamines such as diallyldimethylammonium chloride and diallyldiethylammonium chloride. Of these monomers, dimethyldiallylammonium chloride is particularly preferably used. Although the above diallylamines can be used for the purpose of the present invention even if they are homopolymers, copolymers of the above monomers with monomers copolymerizable with the above monomers are preferable. For example, nonionic water-soluble monomers include acrylylamide, methacrylamide, dimethylacrylamide, N-isopropylacrylamide,
N-vinylformamide, N-vinylacetamide,
N-vinylpyrrolidone and the like can be mentioned. Examples of the water-insoluble monomer include acrylonitrile, methyl acrylate, and vinyl acetate. Examples of the water-insoluble monomer include styrene and octylacrylic acid.
These water-soluble monomers and water-insoluble monomers can be copolymerized in a molar percentage within a range where the polymer after polymerization is water-soluble or water-dispersible.

The ionic monomer can also be copolymerized within a range that does not affect the performance. For example, dimethylaminoethyl (meth) acrylate, salts of organic and inorganic acids of dimethylaminopropyl (meth) acrylamide, or (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride, Alternatively, (meth) acryloyloxy (2-hydroxy) propyltrimethylammonium chloride, or (meth) acrylic acid, itaconic acid, acrylamide 2
-Methylpropanesulfonic acid and the like.

The molar percentage of the diallylamine-based monomer in the diallylamine-based polymer is generally 5 to 50 mol%, preferably 5 to 30 mol%, particularly preferably 10 to 30 mol%. If the amount is less than 5 mol%, the size fixing effect decreases, and if the mol% of the diallylamine-based monomer is 50 mol% or more, the influence on the fluorescent dye is increased, which is not preferable.

The diallylamine-based polymer can be polymerized by any method. Aqueous solution polymerization, reversed-phase emulsion polymerization, dispersion polymerization, etc. can be used as appropriate, but considering the preparation of the coating dispersion, the aqueous solution polymerization is considered to be the most suitable. It is practical because it can be used in a state. The polymerization temperature can be from 0 to 100 ° C,
30-80 ° C based on the reactivity of the diallylamine monomer
Is suitable. The polymerization concentration is generally 20 to 60% by weight, but in consideration of the reactivity of the diallylamine-based monomer, if the diallylamine-based monomer is charged in the reaction vessel and the acrylic monomer is copolymerized, The copolymerizability is improved when the acrylic monomer is supplied intermittently or continuously.

The polymerization is generally carried out in a neutralized state.
The reaction is performed in the pH range of 2 to 8. The initiator may be a redox initiator, for example, a combination of ammonium or potassium peroxodisulfate with sodium hydrogen sulfite, tetramethylethylenediamine, or the like, but an azo initiator, for example, an oil-soluble 2,2-azobisisobutyro. Nitrile, 2,2-azobis (2-methylbutyronitrile), 2,2-azobis (4-methoxy-2,4 dimethylvaleronitrile), or water-soluble 2,2-azobisamidinopropane dichloride 2,2-azobis [2- (5-methyl-2-imidazolin-2-yl)
Propane] dihydrochloride can be used, but water-soluble is preferred.

The molecular weight of the diallylamine polymer is 10
The number is from 10,000 to 5,000,000, preferably from 500,000 to 5,000,000, more preferably from 1,000,000 to 1,000,000. If it is less than 100,000, the size fixing effect is low and not practical. On the other hand, if it is 5,000,000 or more, not only is the viscosity too high, handling is inconvenient, but also the risk of lowering the quality of the formed paper is undesirable.

As a method for adding the diallylamine-based polymer used in the present invention, it is preferable to add the filler at the same time as the filler or the filler. In the papermaking process, a filling yield improver is added to improve the yield on the wire, or a total yield improver is added to packing paper, card paper and the like that do not contain a filler. That is, when a sizing agent, a fluorescent dye, or a rosin sizing agent for neutral papermaking or acidic papermaking is added, a sulfuric acid band is added, and then a diallylamine-based polymer is added. Thereafter, the papermaking raw material is diluted with white water, a retention agent is added, and the diluted papermaking material is sent to a papermaking machine. If examined in more detail, alkyl ketene dimer or alkenyl succinic anhydride-based sizing agent, after adding them, rosin-based sizing agent rosin-based sizing agent, sulfate band, fixing agent in the order, Alternatively, it is considered that the standard order is a sulfate band, a rosin-based sizing agent, and a fixing agent.

The location where the size fixing agent used in the present invention is added may be in a pipe before a fan pump in which white water is added to and diluted with the papermaking raw material, or in white water for diluting the papermaking raw material. However, it is not preferable after the addition of the total yield enhancer or the total yield enhancer. This is because the two drugs are usually cationic and have a risk of affecting the fluorescent dye. Further, it is more efficient and efficient to use a place where all the papermaking raw materials are mixed, such as a machine chest, instead of individual raw material chests.

The sizing agent used is an acid paper sizing agent,
That is, rosin size for acidic papermaking and rosin size for neutral papermaking used in neutral to alkaline, alkyl ketene dimer and alkenyl succinic anhydride can be used.However, when rosin size for neutral papermaking is most used. preferable. The fluorescent dye to be used may be cationic, nonionic or anionic.However, since the anionic fluorescent dye is most affected by the fixing agent, use the fixing agent of the present invention when using an anionic fluorescent dye. Is more preferred.

The amount of the fixing agent of the present invention varies depending on the papermaking conditions and the type of paper.
5% to 0.5%, preferably 0.01% to 0.2%
%. No effect at less than 0.005%, 0.5%
If it is above, not only does it not match the cost, but also adversely affects the paper quality such as lowering the effect of the retention aid added later. Applicable papermaking raw materials are used for paper containing a fluorescent dye, and include high quality paper, printing paper, high quality paperboard, and the like, and can also be used for the surface layer LBKP layer of a cardboard liner.

[0026]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Synthesis Example-1 Thermometer, stirrer, nitrogen inlet tube, peristaltic pump (SMP
Dimethyl diallylammonium chloride (trade name: DA-21) in a 500 mL four-necked flask equipped with a monomer supply tube and a condenser connected to Model -21, manufactured by Tokyo Rikakiki Co., Ltd.
18.6 g of DMAC, 65% by weight, manufactured by Daiso, acrylamide (trade name, acrylamide, 50% by weight)
Product, manufactured by Nitto Chemical Co., Ltd.), 20 g of 30% by weight,
07g, 0.18 of 2-propanol as a chain transfer agent
g (0.3% per total monomer), 5 g of a 0.7% aqueous solution of 2,2-azobisamidinopropane dichloride as a polymerization initiator (0.25% per total monomer)
Were charged. While stirring the raw material mixture, the temperature was kept at 42 ° C., nitrogen was introduced, and polymerization was allowed to proceed for 30 minutes. Then, 140 g of a 30% by weight aqueous solution of acrylamide was supplied into the flask at 0.58 g / min for 4 hours. After the end of the supply, the molar ratio of DADMAC to acrylamide is 1
0:90. After completion of the supply, 5 g of a polymerization initiator solution was added in 8 hours. Twelve hours after the start of the polymerization, the heat retention was stopped to stop the polymerization. Thereafter, the weight average molecular weight was measured by a molecular weight measuring device (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.) by a static light scattering method, and the cation equivalent (meq / g) of the polymer was measured by a colloid titration method. In the same operation, DADMAC is 3, 5, 10, 20, 30, 50, 1
In this case, a polymer of 00 mol% was synthesized. Table 1 shows the physical properties of each polymer.

SYNTHESIS EXAMPLE 2 Each of acryloyloxyethyltrimethylammonium chloride (DMQ), acryloyloxyethyldimethylbenzylammonium chloride (DMABC) and acryloylaminopropyltrimethylammonium chloride (DMPQ) was prepared in the same manner as in the synthesis example. A 30 mol% polymer was synthesized. The properties are shown in Table 1.

Synthesis Example-3 Thermometer, stirrer, nitrogen inlet tube, peristaltic pump (SMP
60.0 g of N-vinylformamide (trade name: N-vinylformamide, manufactured by Mitsubishi Chemical Corporation) in a 500 mL four-necked flask equipped with a monomer supply tube and a condenser connected to -21 type, manufactured by Tokyo Rikakiki Co., Ltd. And the whole was adjusted to 300 g with distilled water. 0.18 g of 2-propanol (0.3% per monomer) as a chain transfer agent and 5 g of a 0.7% aqueous solution of 2,2-azobisamidinopropane dichloride as a polymerization initiator ( 0.1 per total monomer.
25%). Nitrogen was supplied into the flask, the internal temperature was maintained at 50 ° C. by a water bath, and then 5 g of a polymerization initiator solution was added 5 hours after the start of heating. Ten hours after the start of the polymerization, the heat retention was stopped to stop the polymerization. Then, 35.3% of concentrated hydrochloric acid of 40 mol% with respect to the charged monomer.
g was added, and a hydrolysis reaction was performed at 70 ° C. for 3 hours and then at 90 ° C. for 5 hours. After the completion of the reaction, the weight average molecular weight was measured in the same manner as in Synthesis Example-1, and the cation equivalent (meq / g) of the polymer was measured by a colloid titration method. As a result of the measurement, it was found that 31.2 mol% of primary amino groups were formed based on the charged monomers, and the molecular weight was 88,000.
This material is designated as polymer NO13 and PVAm-30.

(Examples 1 to 7) 667 ml of a 0.75 dispersion of L-BKP (Canadian Standard Freeness, CSF = 420) was sampled, and stirred with calcium carbonate (Tamapa). 10%, Neutral papermaking rosin size (00-00 Arakawa Chemical) 0.6%, Fluorescent dye (Blancopha, Bayer) 1%, Sulfuric acid band 1%, as fixing agent 0.15% of each of the diallylamine-based polymers NO2 to 6 and 8 to 9 of the present invention, a retention aid (Himoloc DR-150)
0.010% (both per dry pulp) was added in this order at intervals of 20 seconds, and a paper having a basis weight of 80 g / m2 was produced using a TAPPI standard paper machine.
The pH during papermaking was 6.8. The wet paper thus formed was treated at 3.5 kg / m 2 for 5 minutes and dried at 100 ° C. for 2 minutes. The dried paper was conditioned at 20 ° C. and 65 RH for 24 hours, and the fluorescence intensity (color difference meter PF-10, manufactured by Nippon Denshoku Industries Co., Ltd.) and the degree of Stekihito size (second) (JIS 812)
2) was measured. The results are shown in Table 2.

(Comparative Examples 1 to 6) As in Examples 1 to 7,
Paper making and test paper were measured for Polymers Nos. 1 and 7 and 11 and no fixing agent added. Table 2 shows the results.

Examples 8 to 14 For polymer Nos. 2 to 6 and 8 to 9, acidic rosin for papermaking (pH adjusted to 4.5 during papermaking) 0.3%, talc 20%, talc 20% Papermaking and test paper were measured in the same manner as in Examples 1 to 7, except that the sulfuric acid band was changed to 3.0%. Table 3 shows the results.

(Comparative Examples 8 to 14) In the same manner as in Examples 8 to 14, measurements were made on papers No. 1 and Nos. 7 to 11 and paper making and test papers when no fixing agent was added. Table 3 shows the results.

(Examples 15 to 21) Papermaking was performed in the same manner as in Examples 1 to 7 except that the alkyl ketene dimer-based sizing agent was changed to 0.2% for the polymer NOs 2 to 6 and 8 to 9 as the sizing agent. The test paper was measured. Table 4 shows the results.

(Comparative Examples 15 to 21) In the same manner as in Examples 15 to 22, papermaking and test paper were measured for Polymers NO1 and 7 to 11 and when no fixing agent was added. Table 4 shows the results.

(Examples 22 to 28) Papermaking was performed in the same manner as in Examples 1 to 7, except that the sizing agent was changed to 0.2% of the alkenyl succinic anhydride-based sizing agent for Polymers 2 to 6 and 8 to 9. The test paper was measured. Table 5 shows the results.

(Comparative Examples 22 to 28) In the same manner as in Examples 23 to 29, measurements were made on papers No. 1 and Nos. 7 to 11 and paper making and test papers when no fixing agent was added. Table 5 shows the results.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L055 AG50 AG65 AG72 AH07 AH09 AH10 AH50 BD13 EA29 EA30 FA17

Claims (10)

[Claims] 1. A size fixing method characterized by adding a diallylamine-based polymer to a papermaking raw material to perform papermaking. 2. The size fixing method according to claim 1, wherein the diallylamine-based polymer is a copolymer of a diallylamine and another vinyl monomer copolymerizable with the diallylamine. 3. The method according to claim 1, wherein the diallylamine-based polymer is a copolymer containing 5 to 50 mol% of diallyldimethylammonium salt units in the constituent monomer units. Size fixing method. 4. A diallylamine-based polymer comprising 5 to 50 mol% of diallyldimethylammonium chloride and 50 to 95 mol%
The size fixing method according to any one of claims 1 to 3, which is a copolymer of acrylamide in an amount of mol%. 5. A diallylamine-based polymer comprising 5 to 30 mol% of diallyldimethylammonium chloride and 70 to 95 mol%.
The size fixing method according to any one of claims 1 to 3, which is a copolymer of acrylamide in an amount of mol%. 6. The diallylamine-based polymer having a molecular weight of 10
2. The method according to claim 1, wherein the number is not less than 10,000 and not more than 5 million.
6. The size fixing method according to any one of items 1 to 5. 7. The size fixing method according to claim 1, wherein a fluorescent dye coexists in the papermaking raw material. 8. The size fixing method according to claim 7, wherein the fluorescent dye is anionic. 9. The size fixing method according to claim 1, wherein the sizing agent is a rosin-based sizing agent. 10. The size fixing method according to claim 1, wherein the diallylamine-based polymer is added before the addition of the total retention aid or the filler retention aid.