JPH06173191A - Sizing agent composition for paper-making - Google Patents

Abstract

PURPOSE:To obtain a sizing agent composition for paper-making process effective in a high-pH range or a neutral range. CONSTITUTION:This sizing agent for paper-making process is produced by emulsifying and dispersing a rosin substance with a dispersing agent consisting of a grafted cationized starch prepared by the graft-polymerization of monomers containing (meth)acrylamide to cationized starch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking sizing composition, more specifically, a rosin-based dispersion type papermaking size in which dispersed particles have a cationic property and are excellent in effect and stability. It is related to agents.

[0002]

2. Description of the Related Art Conventionally, in the papermaking industry, for the purpose of making paper water resistant (sizing), a saponification or dispersion type rosin-based sizing agent is fixed in paper as an aluminum salt of rosin using aluminum sulfate. Came.

However, in recent years, it has been generalized in the paper manufacturing industry to carry out papermaking with calcium carbonate as a filler by using neutral or alkaline. In many cases, calcium carbonate as a coating pigment is mixed into a papermaking system through recycling of waste paper or waste paper, and the papermaking pH becomes neutral or alkaline.

In these cases, conventional rosin-based sizing agents show only a very poor sizing effect and are unusable. Therefore, in the case where the papermaking pH is neutral or alkaline, AKD (alkyl ketene dimer) and ASA (alkenyl succinic anhydride) sizing agents are used.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The use of D and ASA sizing agents has caused various problems such as slipperiness and toner adhesion in terms of paper quality, and the use of these sizing agents has completely solved the problem of stains in the papermaking process. It is hard to say.

From this point of view, it has been attempted to improve the rosin-based sizing agent which has been generally used in the papermaking industry so that it can be used in the neutral pH range. Attempts have been made to obtain a cationic rosin-based dispersion for the purpose of improving the fixability.

Those using cationized starch as a dispersant (JP-A-57-135860 and JP-A-56-45950),
Using a specific polyacrylamide resin
56-169898 and Japanese Patent Laid-Open No. 3-227481) have been proposed, but sufficient effects have not yet been obtained.

The inventors of the present invention have conducted extensive studies to obtain a dispersion of a cationic rosin-based substance which has excellent effects in the pH range of neutral papermaking and has excellent dispersion stability. When a grafted cationized starch prepared by graft-polymerizing monomers containing (meth) acrylamide onto cationized starch (hereinafter referred to as grafted cationic starch) is used, it has excellent dispersibility in a neutral pH range. It was found that a dispersion type sizing composition of a cationic rosin-based substance having an excellent effect can be obtained, and the present invention has been completed.

[0009]

Means for Solving the Problems To summarize the present invention, the present invention provides a papermaking sizing composition in which a rosin-based substance is emulsified and dispersed by a dispersant, wherein the dispersant is a cationized starch ( A sizing composition for papermaking, which is a grafted cationic starch prepared by graft-polymerizing monomers containing (meth) acrylamide. Hereinafter, the technical configuration of the present invention will be described in detail.

The rosin-based substance used in the papermaking sizing composition of the present invention refers to a material which has been processed by various methods from rosin as a raw material to impart suitability as a papermaking sizing agent, and is unsaturated. Acid-added rosin, partial esterified product of unsaturated acid-added rosin with alcohols, partial amidated product with amines, aldehyde-modified rosin,
Phenol aldehyde initial condensation product addition rosin, hydrogenated rosin, esterified rosin and the like and mixtures thereof are included.

That is, the present invention is a sizing composition for papermaking in which the above-mentioned modified rosins are dispersed in water with a specific dispersant, and the most characteristic dispersant of the present invention is cationized starch. It is a modified starch prepared by graft-polymerizing monomers containing (meth) acrylamide, that is, a grafted cationic starch.

In the preparation of the novel dispersants of the present invention, the basis for graft polymerization is cationized starch. As the cationized starch, various kinds can be used, and for example, a low viscosity one obtained by reacting a cationized reagent with starch whose degree of polymerization is lowered by oxidation or enzyme modification is advantageously used.

The cationized starch used in the present invention will be described in more detail. As the cationized starch, raw starches such as corn, potato, tapioca, sweet potato, wheat, rice, etc. can be used as the first and second grade by known means. A variety of cationized modified starches having a basic nitrogen atom in which one or more selected from the primary, tertiary amine and quaternary ammonium groups are introduced are used.

For example, as a method for producing a cationized starch containing a quaternary ammonium group, there are a wet method using an aqueous medium and a dry method utilizing a solid / liquid phase reaction, but a wet method is usually adopted. To be done. This is a method of reacting a cationizing agent consisting of a reaction product of dialkylamine or trialkylamine and epichlorohydrin with starch in an aqueous medium in the presence of an alkali, thereby efficiently producing a cationized starch. be able to.

In the present invention, the monomers to be graft-polymerized with the cationized starch need to be monomers containing (meth) acrylamide.
It goes without saying that other copolymerizable monomers can be used in the present invention in addition to the above monomers.

The above-mentioned (meth) acrylamide is an important graft monomer for imparting non-foaming property and emulsion particle stability to the prepared dispersant. That is, by using (meth) acrylamide, which is a hydrophilic monomer, the grafted cationic starch prepared for the first time is a non-foaming dispersant having excellent emulsion particle stability.

In this respect, when the main graft monomer is not water-soluble, it is necessary to use a surfactant and an organic solvent together during the graft polymerization, so that the resulting grafted cationic starch becomes foamable and the rosin-based substance dispersion The stability of the liquid is impaired.

On the other hand, even when the main monomer is a water-soluble monomer other than (meth) acrylamide, the above-mentioned tendency of foamability is the same and the stability of dispersed particles is also poor.

The grafted cationic starch of the present invention can be prepared by various methods using the above-mentioned graft monomer in the presence of the cationic starch. For example, a method using a so-called grafting catalyst such as a cerium salt is one of them, but it is easily performed by graft-polymerizing the grafting monomers with a known polymerization catalyst in the presence of cationized starch. A graft polymer is obtained.
The grafted cationic starch that is the dispersant of the present invention generally comprises 10 to 95% by weight of cationized starch, 5 to 90% by weight of (meth) acrylamide and other monomers.

In the present invention, when the amount of the cationized starch is more than 95% by weight or less than 10% by weight, both show insufficient dispersibility, and sufficient effects cannot be obtained. The papermaking size composition of the present invention, that is, the papermaking size composition comprising the rosin-based substance and the grafted cationic starch as the dispersant prepared as described above has a solid content of (1) a rosin-based substance ... 50 to 99% by weight, preferably 80 to 97% by weight (2) Grafted cationic starch: 1 to 50% by weight, preferably 3 to 20% by weight, and also a grafted cation. Starch
When it is less than 1% by weight, sufficient dispersion stability cannot be obtained and the size effect is deteriorated.

The sizing composition for papermaking of the present invention contains the above-mentioned rosin-based substance as an essential size component, but other sizing agents such as hydrocarbons can be used as long as they do not impair the effects of the rosin-based substance. It goes without saying that an appropriate amount of resin, ASA, AKD, oil derivative or the like can be blended.

Further, the papermaking sizing composition of the present invention comprises:
Although the above-mentioned grafted cationic starch is used as an essential dispersant, other dispersants, for example, sodium naphthalene sulfonate formalin condensate, sodium lignin sulfonate, or various surfactants may be used in combination. It goes without saying that you can do it.

[0023]

The present inventors have not sufficiently clarified the reason why the papermaking sizing composition of the present invention exhibits excellent stability and excellent effect, but it is speculated as follows.

That is, the rosin-based substance particles themselves are negatively charged. The grafted cationic starch has hydrophilic and water-retaining polymer chains oriented toward the outside on the cationic starch. Therefore, in the dispersion liquid, the grafted cationic starch with the polymer chains facing outward is oriented on the dispersed particles of the rosin-based substance to stabilize the particles. The dispersed particles of the rosin-based substance have a cationic property and effectively and firmly fix to the negatively charged pulp fibers by the action of the grafted cationic starch. From the synergistic effect of the above points, it is considered that excellent results are expressed.

[0025]

EXAMPLES The present invention will now be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples. In the following examples, unless otherwise specified,% means% by weight and part means part by weight.

Production Example 1 285 parts of water was added to 100 parts of absolutely dry matter of oxidation-modified tapioca starch having a paste liquid viscosity of 30 cps of 20% 30 ° C., heated at 85 ° C. for 1 hour and cooled, and then at 50 ° C. at 50 ° C. % 3.4 parts of caustic soda, glycidyl trimethyl ammonium chloride in pure content 1
Add 5.3 parts and react at the same temperature for 4 hours, then cool and
12 parts of 5% sulfuric acid aqueous solution was added, and further water was added to make the total amount 460 parts. The prepared cationized starch had a solid content of 25%, a degree of substitution (DS) of 0.15 and a pH of 4.5. Hereinafter, this is referred to as cationic starch I.

90 parts of a 40% solution of acrylamide, 4 parts of dimethylaminopropylacrylamide and a 15% sulfuric acid aqueous solution were added to 240 parts of a 25% solution of the cationic starch I to adjust the pH to 4.0, and then water was added, After the total amount was 360 parts and the temperature was 35 ° C., 0.8 parts of ammonium persulfate and 0.2 parts of sodium bisulfite dissolved in 10 parts of water were respectively added to carry out polymerization. 3 hours 50
After polymerization was carried out at ˜65 ° C., water was added to bring the total amount to 400 parts to obtain a 25% solution of the grafted cationic starch I. The viscosity (25 ° C.) of the obtained solution was 340 cps.

Production Example 2 255 parts of water was added to 100 parts of the dry matter of the oxidation-modified tapioca starch used in Production Example 1 and heated at 85 ° C. for 1 hour and then cooled to 50 ° C.
In 50 parts, 3.4 parts of 50% caustic soda solution and 29.3 parts of glycidyl trimethyl ammonium chloride in terms of pure content were added,
After reacting at the same temperature for 5 hours, the mixture was cooled, and at 30 ° C., 11 parts of a 15% sulfuric acid aqueous solution was added, and water was further added to make a total amount of 440 parts.
The resulting cationic starch had a solid content of 30% and a degree of substitution (DS) of 0.
3, pH 4.0. This is designated as cationic starch II.

To 233 parts of the 30% solution of the cationic starch II, 60 parts of a 40% aqueous solution of acrylamide and 6 parts of dimethylaminopropylacrylamide were added, and the pH was adjusted with a 15% aqueous sulfuric acid solution.
After adjusting to 4.0, add water to make the total amount 360 parts, warm to 55 ° C, dissolve 1 part ammonium persulfate in 10 parts water and add,
Polymerization at 0 ~ 75 ℃ for 1 hour, 0.3 parts of ammonium persulfate dissolved in 10 parts of water was added, and after polymerization at the same temperature for 2 hours, water was added to make the total amount 400 parts and grafted cationic starch II To obtain a 25% solution of. The viscosity of the obtained solution (25 ℃) is
It was 550 cps.

Production Example 3 Production Example 1 except that oxidation-modified corn starch having a viscosity viscosity of 40% (25 ° C.) of 40 cps was used and 14.7 parts of glycidyl trimethyl ammonium chloride pure content was used.
25% solids, degree of substitution (DS) 0.15, pH
A cationic starch of 4.5 was obtained. Hereafter, this is a cationic starch
It is called III.

To 160 parts of the 25% solution of the cationic starch III, 135 parts of a 40% solution of acrylamide, 6 parts of trimethylaminoethyl acrylate hydrochloride and 65 parts of water were added, and the pH was adjusted to 4.0 with a 15% sulfuric acid solution. After heating to 55 ° C, 2 parts of ammonium persulfate dissolved in 10 parts of water was added, and polymerization was carried out at 70 to 75 ° C for 1 hour.
After being dissolved in 1 part and polymerized at the same temperature for 2 hours, water was added to make the total amount 400 parts to obtain a 25% aqueous solution of grafted cationic starch III having a viscosity (25 ° C.) of 2500 cps.

Production Example 4 The procedure of Production Example 1 was repeated except that 100 parts of a 40% aqueous solution of acrylamide was used instead of 90 parts of a 40% aqueous solution of acrylamide and 4 parts of dimethylaminopropylacrylamide in Production Example 1. A 25% aqueous solution of grafted cationic starch IV having a viscosity (25 ° C.) of 270 cps was obtained.

Production Example 5 (Production of fumarized rosin) 800 parts of gum rosin having an acid value of 165 was heated and melted, then heated while stirring and added with 30 parts of formalin for 20 minutes at 135 ° C., followed by 1 hour. Then, the temperature was raised to 170 ° C., 48 parts of fumaric acid was added, the mixture was reacted at 180 to 200 ° C. for 4.5 hours and then taken out to obtain fumaric acid-added modified rosin (hereinafter referred to as modified rosin A). The obtained modified rosin A has an acid value
The softening point was 200 and the softening point was 101 ° C.

Production Example 6 (Production of triethanolamine esterified and maleated rosin) After 750 parts of gum rosin having an acid value of 165 was melted by heating, the mixture was heated with stirring and at 180 ° C., 60 parts of triethanolamine was added for 10 minutes. Then, the temperature was raised to 200 ° C. over 1 hour, and after reacting at 200 ± 5 ° C. for 2 hours, maleic anhydride 67.
5 parts was added over 10 minutes, further reacted at 200 ± 5 ° C. for 1 hour and 30 minutes and then taken out to obtain triethanolamine esterified maleic acid modified rosin (hereinafter referred to as modified rosin B). The modified rosin obtained had an acid value of 124 and a softening point of 90 ° C.

Production Example 7 (Production of Glycerin Esterified and Maleated Rosin) To 500 parts of gum rosin having an acid value of 165, 24 parts of glycerin was added, and the mixture was reacted in a nitrogen stream at 250 ± 5 ° C. for 5 hours, then the temperature was lowered to 200. ℃
In, 45 parts of maleic anhydride was added over 10 minutes,
Further, the mixture was reacted at 200 ± 5 ° C. for 1 hour and 30 minutes and then taken out to obtain a glycerin-esterified maleic acid-modified rosin (hereinafter referred to as modified rosin C). The modified rosin obtained had an acid value of 125 and a softening point of 97 ° C.

Comparative Production Example 1 90 parts of a 40% aqueous solution of acrylamide, 4 parts of dimethylaminopropylacrylamide and 90 parts of water were mixed and the pH was adjusted with sulfuric acid.
Was adjusted to 4.0, 1.0 parts of annimonium persulfate and 1.0 part of sodium bisulfite were dissolved in 5 parts of water at 30 ° C, and a solution was added to start the polymerization, which was kept at an internal temperature of 65 to 70 ° C for 3 hours. In addition, a total amount of 200 parts was used to obtain a polymer I having a concentration of 20% and a viscosity (25 ° C.) of 120 cps.

Comparative Production Example 2 100 parts of a 40% aqueous solution of acrylamide and 85 parts of water were mixed,
After adjusting the pH to 4.0 with sulfuric acid and heating to 35 ° C, 1.0 part of animonium persulfate and 0.3 part of sodium bisulfite dissolved in 5 parts of water were added respectively to start polymerization, and the internal temperature was adjusted to 65-70 ° C for 3 days. After the temperature-controlled polymerization, water was added to make the total amount 200 parts to obtain a polymer II having a concentration of 20% and a viscosity (25 ° C.) of 450 cps.

Comparative Production Example 3 90 parts of a 40% aqueous solution of acrylamide, 4 parts of trimethylaminoethyl acrylate hydrochloride and 90 parts of water were mixed, the pH was adjusted to 4.0 with sulfuric acid, and 1.0 part of annimonium persulfate at 30 ° C.,
A solution prepared by dissolving 1.0 part of sodium bisulfite in 5 parts of water was added, polymerization was started, and the mixture was kept warm at an internal temperature of 65 to 70 ° C for 3 hours and water was added to make the total amount 200 parts, and the concentration was 20% and the viscosity ( 25 ° C) 450 c
A polymer III with ps was obtained.

Example 1 50 parts of the modified rosin A prepared in Preparation Example 5 was heated to 150 ° C. and melted,
20 parts of a 25% solution of the grafted cationic starch I of Preparation Example 1 was mixed with 2.5 parts of polyoxyethylene nonylphenyl ether sulfate ammonium salt and 17.5 parts of water, and the mixture was mixed at 85 ° C.
The solution heated to the above is added with vigorous stirring to form a water-in-oil emulsion, and then hot water is added to shift to an oil-in-water emulsion, and the solid content is 35% of the kaolin rosin-based dispersion type of the present invention. A papermaking sizing agent was obtained.

Example 2 Example 1 was repeated except that the modified rosin B of Preparation Example 6 was used in place of the modified rosin A, and 2 parts of polyoxyethylene nonylphenyl ether sulfate annimonium was used.
The same procedure as in (3) was carried out to obtain a chaotic rosin-based dispersion type papermaking sizing agent of the present invention having a solid content of 35%.

Example 3 The procedure of Example 2 was repeated except that the modified rosin C of Preparation Example 7 was used in place of the modified rosin B, and the cationic rosin-based dispersion type papermaking of the present invention having a solid content of 35% was used. I got a size for use.

Example 4 The procedure of Example 2 was repeated except that the 25% solution of the grafted cationic starch II of Preparation Example 2 was used instead of the grafted cationic starch I. A cationic rosin-based dispersion type papermaking sizing agent of the invention was obtained.

Example 5 The procedure of Example 2 was repeated except that the 25% solution of the grafted cationic starch III of Preparation Example 3 was used in place of the grafted cationic starch I. A cationic rosin-based dispersion type papermaking sizing agent of the invention was obtained.

Example 6 A cationic rosin-based dispersion having a solid content of 35% was prepared in the same manner as in Example 2 except that the grafted cationic starch IV in Preparation Example 4 was used instead of the grafted cationic starch I. A type papermaking sizing agent was obtained.

Example 7 70 parts of modified rosin A prepared in Preparation Example 4 was dissolved in 70 parts of toluene to prepare a 25% solution of the grafted cationic starch I prepared in Preparation Example 28.
Part, 180 parts of water in which 1.4 parts of sodium lignin sulfonate are dissolved, and after stirring and emulsifying, 300 kg / cm with a high pressure homogenizer
^After applying pressure of ² , emulsify through 3 times, depressurize to remove toluene and adjust the concentration by adding water, the cationic rosin dispersion type of the present invention with solid content of 35% A papermaking sizing agent was obtained.

Comparative Examples 1 to 3 Example 1 was repeated except that the grafted cationic starch I of Example 1 was replaced with 25 parts of a 20% aqueous solution of polymers I, II and III of Comparative Preparation Examples 1 to 3. The same operation was performed. The resulting dispersions were adjusted to a solid content of 35% by adding water.

Comparative Examples 4 to 6 Example 2 was repeated except that the grafted cationic starch I of Example 2 was replaced with 17 parts of a 30% aqueous solution of the cationic starches I, II and III of Production Examples 1 to 3. Operate in the same manner as for solid content
A cationic rosin-based dispersion type papermaking sizing composition for comparison of 35% was obtained.

Comparative Examples 7 and 8 Instead of the grafted cationic starch of Example 1, 12 parts of 25% aqueous solution of cationic starch of Preparation Example 1 and 10 parts of 20% aqueous solution of the polymers of Comparative Preparation Examples 1 and 2 are mixed and used. except,
It operated like Example 1. Water was added to each of the obtained dispersions to adjust the solid content to 35%.

Performance Evaluation For each of the sizing compositions of Examples 1 to 6 and Comparative Examples 1 to 8, the properties of the dispersion and the sizing effect when applied as a sizing agent for papermaking were evaluated in the following manner. (a) Properties of dispersion: The state of particles of the obtained dispersion was evaluated by microscopic observation.

(B) Size effect: 1% pulp slurry (L
-BKP, CSF 400 ml) with 10% heavy calcium carbonate as a filler, cationized starch (pearl gum HMS) 0.3
% Aluminum sulfate _{[AL 2 (SO 4) 3} · 13~14H 2 O] 1.5
%, 0.5% and 1.0% of each of the above sizing compositions (addition rates are air dry pulp and solid content weight%) are sequentially added to prepare a wet paper by a TAPPI standard sheet machine as in the conventional method. did. Wet paper is rotary dryer at 90 ℃
It was dried for 1 minute to obtain a paper having a basis weight of 60 g / m ² . The pH of the pulp slurry after addition of chemicals was 7.65, which was almost neutral. After conditioning the humidity at 20 ° C. and a humidity of 65% for 24 hours, the Steckigt sizing degree (JIS P-8122) was measured. Table 1 shows the evaluation results
Shown in.

[0051]

[Table 1]

As is apparent from Table 1, the papermaking sizing composition of the present invention is a dispersion having excellent dispersibility and a stable particle size, and the size effect is obtained even when the pH of the pulp slurry is in the neutral range. Is excellent.

[0053]

INDUSTRIAL APPLICABILITY The present invention relates to improvement of a rosin dispersion which is a sizing agent for papermaking, and has been conventionally used to obtain a cationic rosin dispersion-type sizing agent which is effective at high pH or neutral range. Although a dispersant has been proposed, it is still
The fact is that a practical cationic rosin dispersion sizing agent having both good dispersibility and an excellent size effect has not been obtained. However, the present invention uses cationic starch and (meth) acrylamide as a dispersant. By using the grafted cationic starch prepared by graft-polymerizing the contained monomer as a dispersant, a cationic rosin-dispersed sizing agent having both good dispersibility and an excellent sizing effect in the neutral range can be obtained.

Claims (4)

[Claims] 1. A papermaking size composition obtained by emulsifying and dispersing a rosin-based substance with a dispersant, wherein the dispersant is prepared by graft-polymerizing cationized starch with monomers containing a (meth) acrylamide. A sizing composition for papermaking, which is a cationized starch. 2. The grafted cationized starch is prepared by graft polymerizing 10 to 95% by weight of cationic starch and 5 to 90% by weight of monomers containing (meth) acrylamide. Item 1. A sizing composition for papermaking according to Item 1. 3. The emulsified dispersion comprises 0.5 to 50% by weight of grafted cationic starch and 50 to 99.5% by weight of rosin-based substance in solid content.
The sizing composition for papermaking according to claim 1, which comprises: 4. The papermaking sizing composition according to claim 1, wherein the dispersant comprises a grafted cationic starch and a surfactant.