JP5822154B2 - Manufacturing method of printing / information paper - Google Patents

Description

  The present invention relates to a paper manufacturing method, and more particularly, to a paper manufacturing method capable of suppressing contamination of a paper machine and suppressing size reversion.

  Alkenyl succinic anhydride (hereinafter sometimes abbreviated as ASA) is widely used as a sizing agent for imparting water resistance to paper in the papermaking field. Similarly, 2-oxetanone compounds represented by alkyl ketene dimers are also used as sizing agents. When ASA is used as a sizing agent, the sizing degree of paper immediately after papermaking is superior to that of 2-oxetanone compound as a sizing agent, and the sizing degree is also excellent in waste paper pulp and mechanical pulp. For this reason, with recent paper neutralization, papermaking methods using neutral sizing agents have also been proposed for paperboard (see, for example, Patent Documents 1 and 2).

  Further, a sizing agent fixing method and a paper sizing method for improving the fixing property of a sizing agent by using a diallylamine polymer in combination with a sizing agent have been proposed (Patent Documents 3 and 4).

  However, Patent Documents 1 and 2 are paper making methods for the purpose of avoiding scale troubles and pitch troubles in papermaking systems, and Patent Documents 3 and 4 are methods for improving the effect of general sizing agents. .

  Furthermore, papers that maintain the conventional quality with a small amount of pulp are demanded from the standpoint of the deterioration of the supply situation of raw wood in recent years and environmental protection. However, simply reducing the amount of pulp reduces the paper thickness and decreases the opacity. Therefore, as a countermeasure, a method of adding a large amount of filler is used. As fillers, calcium carbonate, talc, clay, etc. are mainly used, but among them, the tendency to increase the amount of light calcium carbonate added due to the fact that it can be manufactured at a particularly low cost and high whiteness can be achieved. is there.

  However, one of the troubles that easily occur in paper with an increased amount of light calcium carbonate in the paper is a reduction in size over time (hereinafter abbreviated as size reversion). For printing paper and the like, there is a standard for the sizing degree of the paper, and it becomes a big problem that the paper deviates from the standard as the sizing degree decreases with time. There is a need for a paper manufacturing method that does not cause size reversion even when the amount of calcium carbonate in the paper is large, but no paper manufacturing method for improving size reversion has been proposed.

Patent No. 4635512 Japanese Patent No. 4868277 JP 2001-140192 A Japanese Patent Application Laid-Open No. 07-216784

  An object of the present invention is to provide a paper manufacturing method capable of suppressing size reversion while suppressing contamination of a paper machine.

  As a result of intensive studies, the present inventors have found a paper manufacturing method capable of suppressing size reversion while suppressing soiling of a papermaking machine, and have completed the present invention.

That is, the present invention, which is a means for solving the above problems,
(I)
(1) alkenyl succinic anhydride,
(2) Secondary amino group-containing vinyl polymer, which is a copolymer of diallylamine and (meth) acrylamide, and / or primary amino group, which is a cation-modified (meth) acrylamide polymer by Hofmann decomposition reaction of polyacrylamide Vinyl polymer,
(3) a water-soluble aluminum compound,
(4) light calcium carbonate, and (5) amphoteric starch and / or cationic starch ,
(6) (2) The addition amount of the primary and / or secondary amino group-containing vinyl polymer is 50 to 5000 ppm based on the absolutely dried pulp.
(7) To be a paper containing 10% by mass or more of calcium carbonate,
(8) (5) The amount of amphoteric starch and / or cationic starch added is 0.2 to 1.5 mass% with respect to the absolutely dried pulp.
A method for producing printing / information paper , characterized by being added to pulp slurry.
Effect of the invention

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a paper manufacturing method that can suppress soiling of a paper machine, suppress size reversion, and have an excellent size effect.

The present invention provides (1) alkenyl succinic anhydride,
(2) Primary and / or secondary amino group-containing vinyl polymer,
(3) a water-soluble aluminum compound,
(4) Light calcium carbonate, and (5) A method for producing paper, characterized by adding amphoteric starch and / or cationic starch to pulp slurry,
It is.

  The alkenyl succinic anhydride is not particularly limited as long as it is an addition reaction product of an olefin and maleic anhydride, and is preferably an alkenyl succinic anhydride that is liquid at 25 ° C. An alkenyl succinic anhydride produced by an addition reaction of an olefin having 16 to 24 carbon atoms and maleic anhydride is particularly preferred. The internal isomerized olefin is not an α-olefin (an olefin in which the position of the double bond is between the 1st and 2nd positions of the olefin), but the double bond is more carbon chain than the α-position by some method. It is an olefin present inside.

  Specific examples of the alkenyl succinic anhydride include internal isomerized hexadecenyl succinic anhydride, internal isomerized octadecenyl succinic anhydride, internal isomerized icosenyl succinic anhydride, internal isomerized dococenyl succinic acid. An anhydride and an internally isomerized tetracocenyl succinic anhydride can be mentioned, and these may be used singly or as a mixture of plural kinds. A mixture containing a plurality of types of internally isomerized alkenyl succinic anhydrides formed by reacting a plurality of types of internally isomerized olefins with succinic anhydride is also suitable for the internal isomerized alkenyl succinate. It can be employed as an acid anhydride.

  When the olefin used in the alkenyl succinic anhydride has a carbon number of 16 or more and 24 or less, the sizing composition is excellent in the degree of sizing imparted to paper, which is preferable. Further, when an addition reaction product of an olefin containing the internal isomerized olefin and maleic anhydride is used as the alkenyl succinic anhydride, the alkenyl succinic anhydride becomes difficult to hydrolyze, and the sizing composition This is preferable because a decrease in the effect of imparting size to paper is reduced.

  Regarding the internal isomerized olefin, the presence of a double bond inside the α-position of the olefin (position connecting the carbon at the 1st position and the carbon at the 2nd position) is 5.4 ppm in 1H-NMR analysis of the olefin. This can be confirmed by the presence of a peak derived from an internal isomerized olefin in the vicinity. Conversely, when α-olefin is contained, it can be confirmed by the presence of peaks derived from α-olefin in the vicinity of 5.0 ppm and 5.8 ppm in the analysis by 1H-NMR of the olefin. It is also possible to determine the ratio of the α-olefin and the internal isomerized olefin based on the integrated value of the peak.

  The internal isomerized olefin can be synthesized by an ordinary organic synthesis method, and can be obtained, for example, by internal isomerization of an α-olefin using a silica / alumina catalyst. Internally isomerized olefin obtained by internal isomerization of α-olefin by a general organic synthesis method is a mixture of internal olefins in which double bond positions are formed at various positions such as 2-position and 3-position of the carbon chain. However, in this invention, the position of the specific double bond of the internal olefin may not be specified for the internal isomerized olefin, which is a mixture of internal olefins formed by the isomerization reaction. In the internal isomerized olefin containing various internal olefins, the α-olefin content is preferably 10% by mass or less.

  As a method for obtaining alkenyl succinic anhydride by adding maleic anhydride to the olefin, a general organic synthesis method can be applied. For example, alkenyl succinic anhydride can be obtained by gradually adding maleic anhydride to an olefin heated to 210 ° C. in a nitrogen atmosphere and stirring for 6 to 10 hours.

  The alkenyl succinic anhydride is preferably used in the form of an emulsion after being emulsified and dispersed by a conventionally known method. For example, a method of emulsifying and dispersing an alkenyl succinic anhydride containing a surfactant with water or (ionic) starch paste, an alkenyl succinic anhydride containing no surfactant in the presence of a surfactant or Examples thereof include a method of emulsifying and dispersing with a polyacrylamide emulsifier and / or (ionic) starch paste in the absence.

  In the present invention, the location in the papermaking process to which alkenyl succinic anhydride is added is not particularly limited, but it is preferably added to the liquid in the flow path from the beating machine outlet to the inlet inlet in the papermaking process. Further, the alkenyl succinic anhydride can be added not only in one place in the flow path but also in a plurality of places. Further, alkenyl succinic anhydride and other chemicals used in the paper making process may be mixed and added.

  The addition rate of the alkenyl succinic anhydride per dry pulp is usually 0.02 to 1% by mass, preferably 0.04 to 0.3% by mass, based on the active ingredient. The active ingredient of alkenyl succinic anhydride is an alkenyl succinic anhydride having activity in the state contained in the pulp slurry. When the addition rate of alkenyl succinic anhydride is less than the above range, the size effect may be insufficient, and when the addition rate of alkenyl succinic anhydride is more than the above range, the effect only reaches a peak. Operation trouble (foaming, dirt, etc.) may occur.

  Examples of the primary and / or secondary amino group-containing vinyl polymer include a polymer obtained by polymerizing a vinyl monomer, and a polymer having at least a primary or secondary amino group-containing vinyl monomer as a structural unit. Can do. The primary and / or secondary amino group-containing vinyl polymer preferably has 10 mol or more of a primary or secondary amino group-containing vinyl monomer as a unit.

  As the primary and / or secondary amino group-containing vinyl polymer, specifically, a diallylamine homopolymer, a copolymer of diallylamine and a monomer copolymerizable with (meth) acrylamide, or the like, (meth) acrylamide is polymerized. Polymers obtained by Hoffmann reaction or Mannich reaction using a polymer having a component as a starting material, and polymers obtained by hydrolyzing a polymer having N-vinylformamide as a polymerization component can be mentioned, and these can be used alone. Moreover, these 2 or more types can also be used together. Among these, a copolymer of diallylamine and (meth) acrylamide and a cation-modified (meth) acrylamide polymer by Hofmann decomposition reaction of polyacrylamide are preferable, and a copolymer of diallylamine and (meth) acrylamide is more preferable.

  There is no restriction | limiting in particular as a polymerization method of the said primary and / or secondary amino group containing vinyl polymer, A conventionally well-known method is employable.

  When the primary and / or secondary amino group-containing vinyl polymer is added to the pulp slurry, the place of addition in the papermaking process is not particularly limited, but it is added at a place with good mixing in the flow path from the beater outlet to the inlet outlet. It is preferable to do this. In addition, the primary and / or secondary amino group-containing vinyl polymer may be added not only at one location in the flow path but also at multiple locations, and one or two or more of the primary and / or secondary grades may be added. An amino group-containing vinyl polymer may be added.

  As a ratio of adding the primary and / or secondary amino group-containing vinyl polymer to the pulp slurry, the addition ratio of the primary and / or secondary amino group-containing vinyl polymer to the absolutely dried pulp is 50 to 5000 ppm by mass. It is preferable that it is 50-2000 ppm. When the addition rate is less than 50 ppm, the size reversion suppression effect may be insufficient, and when the addition rate exceeds 5000 ppm, the size reversion suppression effect may reach its peak.

  Examples of the water-soluble aluminum compound include aluminum sulfate (sulfuric acid band), polyaluminum chloride, alumina sol, polyaluminum sulfate, polyaluminum sulfate silicate, and aluminum chloride. Of these, aluminum sulfate is preferred. These water-soluble aluminum compounds can be used alone or in combination of two or more.

  The water-soluble aluminum compound produces an alkenyl succinic acid hydrolyzate and salt, thereby reducing the contamination of the paper machine derived from alkenyl succinic acid. Therefore, it is necessary to use a water-soluble aluminum compound in order to suppress soiling in a paper machine and achieve size reversion suppression.

  The water-soluble aluminum compound preferably has an addition rate of 0.1 to 1.5% by mass, more preferably 0.2 to 1.0% by mass, based on the absolutely dried pulp. . If the addition rate is less than 0.1% by mass, there is a case where there is no effect of reducing the stain due to the alkenyl succinic anhydride. If the addition rate exceeds 1.5% by mass, the aluminum compound causes the paper machine to become dirty. There is a fear.

  The light calcium carbonate includes precipitated calcium carbonate, light calcium carbonate, and calcium carbonate chemically produced by baking limestone. The light calcium carbonate may have a relatively coarse particle size of about several μm, but a fine particle size of about 0.1 to 0.02 μm is preferable, and a uniform particle size is preferable. Examples of the light calcium carbonate include crystal types (calcite type, aragonite type), and coarse types (cubic shape, spindle shape, rod shape, etc.), any of which can be used.

  One of the causes of size reversion is considered that alkenyl succinic anhydride moves into calcium carbonate over time. Therefore, when the amount of calcium carbonate in the paper is increased, size reversion tends to occur. When the amount of calcium carbonate in the paper is less than 10% by mass, size reversion tends not to occur, but when it exceeds 10% by mass, size reversion tends to occur. Here, in the present invention, the amount of calcium carbonate in the paper is calculated by measuring the amount of ash in the paper according to JISP-8251.

  The cationic starch is a starch having a cationic group introduced by a cation modification reaction. The amphoteric starch is a starch in which an anionic group is introduced in addition to the cationic group.

  The starch used as a starting material for the amphoteric starch or the cationic starch is not only raw starch that is unprocessed after being taken out from the plant, but also cationic starch obtained by performing various modifications to the raw starch. Chemically modified starch such as oxidized starch and amphoteric starch, and enzyme modified starch obtained by enzymatic modification of the raw starch or the chemically modified starch are also included. As the raw starch, various plants such as potato, sweet potato, tapioca, wheat, rice, corn and the like may be used as a raw material source. These can be used in the form of powder or solution.

  The amphoteric starch and / or cationic starch is preferably added at a rate of 0.2 to 1.5% by mass, and added at a rate of 0.3 to 1.0% by mass with respect to the absolutely dried pulp. More preferably. If the addition rate is less than 0.2% by mass, the alkenyl succinic anhydride may not have a sufficient sizing degree in the paper. If the addition rate exceeds 1.5% by mass, the size reversion suppression effect may reach its peak. is there.

  In introducing the cationic group into the starch, for example, 3-chloro-2-hydroxypropyl / trimethylammonium chloride, glycidyltrimethylammonium chloride, dimethylaminoethyl chloride, etc., which are known cationizing agents such as starch or derivatives thereof Can be introduced by reacting in the presence of a catalyst.

  In introducing the anionic group into the starch, starch or a derivative thereof can be introduced by a known method.

  As the starch having a cationic group, one having a reduced viscosity can be used. Examples of a method for reducing the viscosity of starch include a method of treating starch with an oxidizing agent, or a method of degrading starch by decomposing starch with an enzyme.

  As the oxidizing agent, conventionally known and commonly used oxidizing agents can be used. Specific examples of the oxidizing agent include “hypochlorites such as sodium hypochlorite, potassium hypochlorite, and ammonium hypochlorite”, “persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate”. Sulfates "," peroxides such as benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide "," bromates such as sodium bromate and potassium bromate "," Perborates such as sodium perborate and ammonium perborate "," percarbonates such as sodium percarbonate, potassium percarbonate, ammonium percarbonate "and" sodium perphosphate, potassium perphosphate, superphosphorus Superphosphates such as ammonium acid "can be used. In this case, one kind can be used alone, or two or more kinds may be used in combination.

  Examples of the enzyme used for decomposing and modifying the starch include α-amylase, β-amylase, γ-amylase, isoamylase and the like produced by various bacteria, yeasts, animals and plants. Among these, α-amylase is most preferable in that it does not cause excessive low molecular weight substances or monosaccharides.

  The cationic starch after cooking preferably has a viscosity of a 1% solid content aqueous solution at 25 ° C. of 5 to 10,000 mPa · s, more preferably 5 to 1,000 mPa · s.

(1) alkenyl succinic anhydride,
(2) Primary and / or secondary amino group-containing vinyl polymer,
(3) a water-soluble aluminum compound,
(4) Light calcium carbonate, and (5) The order of adding amphoteric starch and / or cationic starch to the pulp slurry is not particularly limited. (2) Primary and / or secondary amino group-containing vinyl polymer And (1) alkenyl succinic anhydride is preferably added in this order, (5) amphoteric starch and / or cationic starch, (2) primary and / or secondary amino group-containing vinyl polymer More preferably, (1) alkenyl succinic anhydride, (3) water-soluble aluminum compound, and (4) light calcium carbonate are added in this order.

  As pulp raw materials used in the pulp slurry, “bleached or unbleached chemical pulp such as kraft pulp or sulfite pulp”, “bleached or unbleached high yield pulp such as groundwood pulp, mechanical pulp or thermomechanical pulp”, and Any of “used paper pulp such as upper white waste paper, newspaper waste paper, magazine waste paper, cardboard waste paper or deinked waste paper” can be used. Further, when used in the pulp slurry, the pulp raw material can be used as a mixture of polyamide, polyester, polyolefin and the like. Further, a filler is a main raw material used for pulp slurry. Examples of the filler used in the pulp slurry include calcium carbonate, clay, talc, chalk, titanium oxide, and white carbon.

  As pH of the said pulp slurry, pH 6.6-8.2 are preferable, More preferably, 6.7-8.0 are preferable. The pH referred to in the present invention refers to a value measured at 25 ° C. In order to achieve the pH, for example, an alkaline substance such as sodium hydroxide or sodium carbonate or an acidic substance such as sulfuric acid can be used, but the conductivity and alkalinity of the pulp slurry are within a certain range. Therefore, it is preferable to avoid the use that increases these fluctuations.

  The electric conductivity of the pulp slurry for papermaking is preferably 50 to 200 mS / m, more preferably 50 to 150 mS / m. The electric conductivity referred to in the present invention refers to a value measured under the condition of 25 ° C.

  (1) alkenyl succinic anhydride, (2) primary and / or secondary amino group-containing vinyl polymer, (3) water-soluble aluminum compound, (4) light calcium carbonate, and (5) amphoteric starch and Examples of the agent added to the pulp slurry in addition to the cationic starch include additives such as a filler, a sizing agent, a wet paper strength improver, a yield improver, and a drainage improver. These additives may be used as necessary in order to develop the physical properties required for the above. Among these additives, it is preferable to use a yield improver, and it is more preferable to use a cationic yield improver. These additives may be used alone or in combination of two or more. These additives may be mixed with the compounds (1) to (5) in advance and added to the paper stock, and the mixing method is not particularly limited.

  Examples of the filler used for the additive include clay, talc, and heavy calcium carbonate. These may be used alone or in combination of two or more.

  Although it does not restrict | limit especially as paper manufactured by this invention, Various paper and paperboard are mentioned. Specifically, as the type of the paper, “printing / information paper, ie, information paper such as information PPC paper, inkjet printing paper, laser printer paper, form paper, thermal transfer paper, thermal recording base paper, pressure recording base paper” , “Various non-coated printing paper such as high-grade printing paper, intermediate printing paper, and lower-grade printing paper” and “Coated printing paper such as photographic paper and its base paper, art paper, cast coated paper, high-quality coated paper” . Other types of paper include “wrapping paper such as kraft paper and pure white roll paper”, “other papers such as notebook paper, book paper, and newspaper (Western paper)”, “Manila balls, white balls, chips” Paper board for paper containers such as balls "and" paperboard such as liners and gypsum board base paper ". The manufacturing method in the present invention can be applied to a manufacturing method other than paper, and examples thereof include a method for manufacturing modified wood or inorganic building materials. Examples of the inorganic building material include a particle board, a hard board, an insulation board, and a rock wool board. Among these, it is particularly preferable to apply to printing / information paper, which is a paper that easily undergoes size reversion.

  As the size reversion, it is preferable that the sizing degree after 24 hours after paper making and the sizing degree after one month do not change by 30% or more, and particularly preferably do not change by 10% or more. If is not large, it may be allowed.

  Hereinafter, the present invention will be described by way of examples. In addition, in an example, a part and% show a mass part and mass%, respectively.

<Preparation Example 1>
Preparation of water dispersion of alkenyl succinic anhydride 15 parts by mass of sizing agent AS1532 (manufactured by Seiko PMC Co.) which is an alkenyl succinic acid sizing agent and emulsifier SP1808 (manufactured by Seiko PMC Co.) which is a polyacrylamide emulsifier 3 parts by mass is mixed, emulsification is performed at 10,000 rpm for 60 seconds using a universal homogenizer (manufactured by Nippon Shiki Seisakusho), water is added, alkenyl succinic anhydride is 1% by mass, and the particle size is 0.00. A water dispersible sizing agent of 8 μm was obtained.

Example 1
Bleached kraft pulp (mixed pulp with softwood to hardwood pulp ratio of 1 to 9) is diluted with water with a conductivity of 100 mS / m so that the pulp concentration is 2.4% by mass, and a Canadian standard freeness using a beater. Beat until 390. Next, 1.2 liters of the obtained pulp slurry was weighed, and with stirring, 5% by mass of light calcium carbonate for pH adjustment (Tama Pearl 121, manufactured by Okutama Kogyo Co., Ltd.) was added to the absolutely dried pulp, , Cationic starch Cato304 (manufactured by Nippon SC Co., Ltd.) was added in an amount of 0.5% by mass to the absolutely dried pulp, and the resulting pulp slurry was concentrated with diluted water having a pH of 7.5 and an electric conductivity of 100 mS / m. Add 0.025% by mass to the dry pulp of FX7200 (manufactured by Seiko PMC Co., Ltd.), a secondary amino group-containing vinyl polymer (copolymer of diallylamine and acrylamide) diluted to 0.8% by mass. After that, 0.15% by mass of the water-dispersible sizing agent of Preparation Example 1 was added to the absolutely dried pulp in terms of alkenyl succinic anhydride. After adding 0.5% by mass to the completely dried pulp and 40% by mass of the above light calcium carbonate with respect to the completely dried pulp, a cationic yield improver (yield improver RD7153 manufactured by Seiko PMC Co., Ltd.) is added. 0.03% by mass was added to the absolutely dried pulp to obtain a pulp slurry A.

<Evaluation of size reversion (size reduction rate) and evaluation of the amount of calcium carbonate in paper>
Using this pulp slurry A, a sheet was hand-made with a noble and wood sheet machine to a basis weight of 65 g / m 2 and dried with a drum dryer (100 ° C., 80 seconds). The obtained paper was conditioned in a constant temperature and humidity chamber at 23 ° C. and 50 RH% for 24 hours, and then the squeecht size was measured according to JISP-8122 to be 15.2 seconds. The larger the measured value, the more difficult the aqueous solution penetrates into the paper, which means that the size of the paper is excellent. Further, the amount of ash in the paper was calculated by measuring according to JISP-8251 as the amount of calcium carbonate in the obtained paper. Further, after the obtained paper was stored in a constant temperature and humidity room at 23 ° C. and 50 RH% for one month, the sizing degree was measured in the same manner, and it was 15.0 seconds. The difference between the sizing degree and the sizing degree after 1 month divided by the sizing person sizing degree after 24 hours is used as the sizing degree reduction rate, and the change in sizing degree over time (size reversion) is evaluated. did. A smaller value indicates that size reversion is less likely to occur. Table 1 shows the result of the size reduction rate.
Further, as an index of the amount of calcium carbonate in the obtained paper, the amount of ash in the paper was measured according to JISP-8251. Table 1 shows the amount of calcium carbonate in the obtained paper.

<Dirt evaluation>
After stirring this pulp slurry A at 45 ° C. for 60 minutes, according to a conventional method, hand-pulling with a noble and wood sheet machine to 65 g / m 2, placing a metal plate on the wet paper, and 4.2 kgf for 2 minutes A flat press was performed. The metal plate was peeled from the wet paper, and the amount of dirt attached to the metal plate was visually evaluated in five stages (1 to 5 dirt with little dirt). The more dirt is deposited on the metal plate, the more easily dirt is deposited in the paper machine system. Table 1 shows the results of the dirt evaluation.

(Example 2)
FX7200, which is a secondary amino group-containing vinyl polymer (a copolymer of diallylamine and acrylamide) used in Example 1, was converted into a primary amino group-containing vinyl polymer (cation-modified acrylamide polymer by Hofmann decomposition reaction of polyacrylamide). Instead of the paper strength agent DH4160 (manufactured by Seiko PMC Co., Ltd.), the rate of reduction in size was reduced in the same manner as in Example 1 except that the addition rate was changed to 0.1% by mass with respect to the absolutely dried pulp. Obtained and evaluated for dirt. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 14.8 seconds, and the dexterity degree after 1 month was 13.8 seconds.

(Example 3)
Except that the cationic starch used in Example 1 was replaced with the amphoteric starch Cato3210 (manufactured by Nippon SC Co., Ltd.), the rate of reduction in size was determined in the same manner as in Example 1 to evaluate the stain. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 15.4 seconds, and the dexterity degree after one month was 15.1 seconds.

(Equivalent to comparative example)
Except for reducing the addition rate of the cationic starch used in Example 1 from 0.4% by mass to 0.1% by mass with respect to the absolutely dried pulp, the rate of reduction in sizing was the same as in Example 1. Obtained and evaluated for dirt. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 8.2 seconds, and the dexterity degree after one month was 7.6 seconds.

Example 4
The addition rate of FX7200, which is a secondary amino group-containing vinyl polymer (a copolymer of diallylamine and acrylamide) used in Example 1, was reduced from 0.025% by mass to 0.01% by mass with respect to the absolutely dried pulp. Except for the above, the sizing degree reduction rate was determined in the same manner as in Example 1 to evaluate the stain. The results are shown in Table 1. In addition, the schiecht sizing degree after 24 hours was 14.8 seconds, and the schiecht sizing degree after 1 month was 14.4 seconds.

(Reference example)
In Example 1, except that the amount of calcium carbonate added after the pulp slurry was diluted to a concentration of 0.8% was reduced from 30% to 10%, the size reduction rate was obtained in the same manner as in Example 1. The dirt was evaluated. The results are shown in Table 1. In addition, the succito sizing degree after 24 hours was 28.9 seconds, and the schit sizing degree after 1 month was 28.5 seconds.

(Comparative Example 1)
Except that the secondary amino group-containing vinyl polymer (copolymer of diallylamine and acrylamide) used in Example 1 was not used, the sizing degree reduction rate was determined in the same manner as in Example 1 to evaluate the stain. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 14.0 seconds, and the dexterity degree after one month was 9.4 seconds.

(Comparative Example 2)
Other than the above that does not use a secondary amino group-containing vinyl polymer used (copolymer of diallylamine and acrylamide) in Reference Example to obtain the size of reduction rate in the same manner as in Reference Example were evaluated dirt. The results are shown in Table 1. In addition, the degree of strict human sizing after 24 hours was 26.5 seconds, and the degree of strict human sizing after one month was 23.3 seconds.

(Comparative Example 3)
The primary amino group-containing vinyl polymer paper strength agent DH4160 used in Example 1 is a paper strength agent WS4020 (manufactured by Seiko PMC Co., Ltd.), which is a condensation polymer (polyamide polyamine-epihalohydrin resin) containing a primary to quaternary amino group. Except for changing to, the sizing degree reduction rate was determined in the same manner as in Example 1 to evaluate dirt. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 14.4 seconds, and the dexterity degree after one month was 10.0 seconds.

(Comparative Example 4)
The primary amino group-containing vinyl polymer paper strength agent DH4160 used in Example 1 is a quaternary amino group-containing vinyl polymer (polydiallyldimethylammonium chloride) that is not a primary and / or secondary amino group-containing vinyl polymer. Except for changing to agent AC7304 (manufactured by Seiko PMC Co., Ltd.), the rate of reduction in size was determined in the same manner as in Example 1 to evaluate the stain. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 14.2 seconds, and the dexterity degree after one month was 9.8 seconds.

(Comparative Example 5)
Except that the secondary amino group-containing vinyl polymer (copolymer of diallylamine and acrylamide) used in Example 3 was not used, the sizing degree reduction rate was determined in the same manner as in Example 3 to evaluate the stain. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 14.9 seconds, and the dexterity degree after one month was 10.2 seconds.

(Comparative Example 6)
Except not using a secondary amino group-containing vinyl polymer used in the Comparative Example corresponds (copolymer of diallylamine and acrylamide) determines the size of reduction rate in the same manner as corresponding comparative example was evaluated dirt. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 8.0 seconds, and the dexterity degree after one month was 5.2 seconds.

(Comparative Example 7)
Except that no addition of the added aluminum sulfate in Example 4 to obtain the size of reduction rate in the same manner as in Example 4, were evaluated dirt. The results are shown in Table 1. In addition, the dexterity degree after 24 hours was 13.5 seconds, and the dexterity degree after 1 month was 12.5.

From the results in Table 1, Examples 1 to 4 produced under the conditions of the present invention have a sizing reduction rate of 10% or less even after one month. On the other hand, Comparative Examples 1, 5 and 6 in which the primary and / or secondary amino group-containing vinyl polymer was not used, and Comparative Examples 3 and 4 in which other than the primary and / or secondary amino group-containing vinyl polymer were used The degree of size reduction after 1 month is 30% or more. Therefore, it turns out that the primary and / or secondary amino group containing vinyl polymer in this invention has a size reversion inhibitory effect. Since Comparative Example 2 has less calcium carbonate in the paper than Comparative Example 1, size reversion is less likely to occur, but the rate of reduction in size after one month is 10% or more.
Also, with respect to dirt, Comparative Examples 1, 2, 5, and 6, which did not use a primary and / or secondary amino group-containing vinyl polymer, Comparative Examples using other than primary and / or secondary amino group-containing vinyl polymers It can be seen that Examples 1 to 4 produced under the conditions of the present invention are less contaminated than 3 and 4 and Comparative Example 7 in which no sulfuric acid band was added.

Claims (1)

(1) alkenyl succinic anhydride,
(2) Secondary amino group-containing vinyl polymer, which is a copolymer of diallylamine and (meth) acrylamide, and / or primary amino group, which is a cation-modified (meth) acrylamide polymer by Hofmann decomposition reaction of polyacrylamide Vinyl polymer,
(3) a water-soluble aluminum compound,
(4) light calcium carbonate, and (5) amphoteric starch and / or cationic starch ,
(6) (2) The addition amount of the primary and / or secondary amino group-containing vinyl polymer is 50 to 5000 ppm based on the absolutely dried pulp.
(7) To be a paper containing 10% by mass or more of calcium carbonate,
(8) (5) The amount of amphoteric starch and / or cationic starch added is 0.2 to 1.5 mass% with respect to the absolutely dried pulp.
A method for producing printing / information paper , which is added to pulp slurry.