JP3223649B2 - Sizing agent for neutral papermaking, production method thereof, sizing method and sizing paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a use method for producing a rosin material and Ke Tendaima acids and neutral papermaking sizing agent containing containing rosin esters, that for neutral papermaking sizing agents, the sizing agent Sizing method and sizing paper.

[0002]

2. Description of the Related Art In the papermaking industry, neutral papermaking or alkali papermaking using inexpensive calcium carbonate as a filler is widely used in order to avoid problems in an acidic papermaking method using a sulfuric acid band. As the sizing agent for this purpose, rosin-based substances including alkyl ketene dimers, alkenyl succinic anhydrides, and rosin esters are used as main raw materials.

[0003] However, with regard to alkyl ketene dimers, when an aqueous dispersion of an alkyl ketene dimer is used to make paper, operational troubles often occur such that the press roll and the smoother roll of the paper machine are easily stained. Paper sized using an aqueous dispersion of an alkyl ketene dimer exhibits a slow size effect (so-called slow size rise). Paper sized using an aqueous dispersion of an alkyl ketene dimer is slippery and often causes trouble during its processing or use. And the like.

Further, alkenyl succinic anhydrides cannot be stored in the form of an aqueous dispersion because they are easily hydrolyzed. Therefore, a sizing agent is prepared by emulsifying and dispersing in water immediately before papermaking. There is a major manufacturing constraint that it must be done. In addition, when paper is made using a sizing agent containing alkenyl succinic anhydride as a main component, dirt easily adheres to the paper machine, which often causes operational troubles. If you are limited to.

For rosin-based substances containing esters with rosin, a method for sizing a neutral paper is disclosed in Japanese Examined Patent Publication No. 79798/1991, in which a tri- or tetra-hydric alcohol and a rosin ester are used as dispersed phases. It is disclosed that papermaking is performed using a sizing agent composed of an aqueous dispersion.However, when the papermaking conditions are not properly controlled when using the sizing agent, the desired sizing degree cannot be obtained, and the sizing performance is poor. Since it is low, it is necessary to increase the sizing agent addition rate, and there is a problem that the sizing agent cost increases.

[0006]

As described above, the alkyl ketene dimer sizing agent has a problem that the paper machine is easily stained, the rise of the size is slow, and the sizing paper is also slippery. The acid-based sizing agent has a problem in production and the like, and the rosin-based sizing agent containing rosin esters has a problem that it is difficult to set the papermaking conditions. Japanese Patent Publication No. 59-51637 discloses a sizing agent in which a rosin ester and an alkyl ketene dimer are simultaneously dispersed in water with a cationized starch or the like, but further improvement of the sizing effect has been desired. .

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have separately separated a rosin-based substance containing at least one of rosin esters and their fortified substances and a ketene dimer. After making the aqueous dispersion, both
The weight ratio of the rosin-based material to the ketene dimer is 99: 1 to 1
The sizing agent obtained by mixing at a ratio of 65:35 exerts an excellent sizing effect, and it has been found that sizing using the sizing agent can solve the above-mentioned problems, leading to the present invention. That is, the present invention includes a rosin-based substance (A) containing at least one of a rosin ester which is a reaction product of at least one rosin and its fortified product with an alcohol and at least one of its fortified products. A method for producing a neutral papermaking sizing agent comprising mixing an aqueous dispersion (B) and an aqueous dispersion (D) containing a ketene dimer (C), wherein the rosin-based substance (A) Ketenda
The weight ratio (A) :( C) of the immers (C) is 99: 1 to 6
The present invention provides a method for producing a neutral papermaking sizing agent having a ratio of 5:35 .

In this case, the rosin ester is an esterified product of at least one of rosins and their fortified substances and at least one of trihydric and tetrahydric alcohols. In each case, dispersant (E),
(F) at least one of an acrylamide-based copolymer, a methacrylamide-based copolymer, an acrylamide-methacrylamide-based copolymer and an anionic copolymer composed of a salt thereof or a combination thereof with a low molecular surfactant It is also preferable to use them.

Further, the present invention uses the sizing agent obtained as described above in a pH range of 6.5 to 9.0,
The present invention provides a sizing method and a sizing paper, and in that case, it is also preferable to use calcium carbonate as a filler.

[0010] At least one of a rosin ester and a fortified product thereof used in the method for producing a sizing agent for neutral papermaking of the present invention.
The rosin-based substance (A) containing a species is at least one of rosins and their fortified substances (hereinafter referred to as rosins and the like).
And preferably at least one of rosin esters, which are esterified products formed by dehydration condensation with an alcohol mainly containing at least one of trihydric and tetrahydric alcohols, and fortified products thereof. It may contain at least one of rosins and their fortified substances.

Representative rosins include gum rosin, tall oil rosin and wood rosin, which are used alone or as a mixture of two or more. Further, rosins obtained by subjecting the above rosins to treatments such as disproportionation, hydrogenation, aldehyde modification, and polymerization, alone or in combination of two or more thereof are also included in the rosins. The rosin-enhanced product is obtained by subjecting a rosin to an addition reaction of a ─C─C─C ＝ O group-containing acidic compound at 1 to 20% by weight, preferably 3 to 15% by weight. Representative examples of the acidic compound include α, β─ unsaturated carboxylic acids and anhydrides thereof. Specifically, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, Examples thereof include citraconic acid, citraconic anhydride, acrylic acid, and methacrylic acid. The reinforcing method can be performed by a known method. The fortified rosin ester refers to a substance obtained by adding the above α, β─ unsaturated carboxylic acid, an anhydride thereof or the like to the above rosin ester, for example, 1 to 20% by weight based on the rosin ester, Preferably, 3 to 15% is added.

3 used to obtain the above rosin esters
Examples of the trivalent to tetravalent alcohol include glycerin, trimethylolethane, trimethylolpropane,
Examples thereof include 3-methylpentane-1,3,5-triol, pentaerythritol, and diglycerin, and these can be used alone or in combination of two or more.

As the alcohol, monohydric, dihydric or other alcohols can be used in combination. Specifically, n-
Octyl alcohol, 2-ethylhexyl alcohol,
Decyl alcohol, lauryl alcohol, stearyl alcohol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol,
Dipropylene glycol, polypropylene glycol,
Neopentyl glycol and the like.

[0014] The Rojin'esu to obtain Te Le acids, the equivalent ratio of the rosin and the like and trivalent and tetravalent alcohol and at least one, and hydroxyl group of the carboxyl group with an alcohol, such as rosins (─COOH ( eq) / ─OH (eq))
At a temperature of 150 to 300 ° C. in the presence or absence of a catalyst under known esterification reaction conditions, for example, under normal pressure, reduced pressure, or increased pressure. The dehydration reaction may be performed while stirring for 3 to 30 hours. At this time, dehydration may be performed azeotropically using a solvent such as benzene, xylene, and toluene. In the above equivalent ratio, carboxyls such as rosins do not include carboxyls derived from α, β─ unsaturated carboxyl groups added to rosin such as fortified rosin. Equivalent ratio is 0.5
If the amount is less than the above, a large amount of free hydroxyl groups remains in the rosin ester to be formed, and when this is used as a main component of the sizing agent, the size effect is reduced due to the remaining hydroxyl groups, which is not preferable. On the other hand, if the equivalent ratio is larger than 1.5, the resulting sizing agent is not sufficiently improved in the sizing effect in a neutral or alkaline region, which is not preferable.

The above-mentioned rosin esters are usually a fully esterified product in which all of the hydroxyl groups of at least one of trihydric and tetrahydric alcohols are esterified with a carboxyl group such as rosin, etc. Various mixtures of partially esterified products in which the part is esterified (excluding carboxyls caused by α, β─ unsaturated carboxyl groups added to rosin such as fortified rosin) and unreacted raw materials are used in the present invention. May be used as it is as the disperse phase of the aqueous dispersion as long as it is within the above-mentioned equivalence ratio. This rosin ester usually has a content of 6% in solids.
It contains 0% by weight or more of the above fully esterified product, partially esterified product or a mixture of both. If necessary, rosins and the like may be added to the rosin esters.

[0016] In the present invention, the Quai Tendaima class,
It is a compound represented by the following general formula, and any of various ketene dimer compounds can be used.

[0017]

Embedded image

In the above formula, R1 and R2 each represent the same or different hydrocarbon group having 8 to 30 carbon atoms, and examples of the hydrocarbon group include decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl and the like. Examples include an alkyl group, an alkenyl group such as tetradecenyl, hexadecenyl, and octadecenyl; a substituted phenyl group such as octylphenyl and nonylphenyl; an alkyl-substituted cycloalkyl group such as nonylcyclohexyl; and an aralkyl group such as phenylethyl. Is preferred. These ketene dimer compounds are used alone or in combination of two or more.

In the present invention, the dispersant (E) is an acrylamide copolymer, a methacrylamide copolymer,
It contains at least one anionic copolymer composed of an acrylamide / methacrylamide copolymer and a salt thereof (hereinafter, these may be collectively referred to as a (meth) acrylamide copolymer). (Meth) acrylamide-based copolymers include, as anionic monomers, monomers having a carboxylic acid group such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, and vinyl sulfonic acid , (Meth) allylsulfonic acid, 2-acrylamide-
Monomers having a sulfonic acid group such as 2-methylpropanesulfonic acid and sulfonated styrene, monomers having a phosphoric ester group such as a phosphoric acid ester of hydroxyalkyl (meth) acrylate, and alkali metal salts and ammonium salts of these acids If necessary, at least one of styrene, a styrene derivative, an alkyl (meth) acrylate, a vinyl ester such as (meth) acrylonitrile, vinyl acetate and vinyl propionate, and at least one other hydrophobic monomer such as a vinyl ether. And a copolymer obtained by copolymerizing with a (meth) acrylamide together with the nonionic vinyl-based monomer.

In order to synthesize the above-mentioned anionic (meth) acrylamide copolymer, conventionally known methods such as solution polymerization, emulsion polymerization, dispersion polymerization and precipitation polymerization can be applied. For example, in the case of solution polymerization, the above-mentioned vinyl monomer is mixed with an organic solvent such as lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol or tertiary butyl alcohol, acetone, methyl ethyl ketone or dioxane, or a mixture of these organic solvents and water. In a mixed solution of the above, and the organic solvent is distilled off after completion of the polymerization. At this time, the copolymer formed during the polymerization may be insolubilized and precipitate (precipitation polymerization). At that time, a dispersion stabilizer such as polyvinyl alcohol or a (meth) acrylic acid (co) polymer is previously added to the polymerization system. (Dispersion polymerization). In the case of emulsion polymerization, the above monomer is dispersed in water in the presence of a known anionic and / or nonionic surfactant, and polymerized by a radical polymerization catalyst. In this case, emulsifier-free emulsion polymerization without adding a surfactant is also possible.

In the obtained anionic (meth) acrylamide copolymer, an anionic monomer unit may be converted into a salt, if necessary, or the copolymer may be obtained by using a salt type anionic monomer. You may do it. This salt may be neutralized during or after the copolymerization reaction of the reaction system using an anionic monomer to form a salt.

Examples of the radical polymerization catalyst include persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, redox polymerization catalysts obtained by combining these persulfates and reducing agents, and 2,2'-azobis An azo catalyst such as isobutyronitrile can be used. Also, in order to adjust the molecular weight of the copolymer, a known chain of alkyl mercaptans, thioglycolic acid or its esters, mercaptopropionic acid or its esters, mercaptoethanol, thioglycol, carbon tetrachloride, etc., if necessary. A transfer agent can be appropriately used in combination.

As the alkyl mercaptans, alkyl mercaptans having 6 to 22 carbon atoms, such as n-octyl mercaptan and n-dodecyl mercaptan, are preferred.
0.01 to 10 mol% based on the total amount of monomers in the reaction system,
Most preferably, it is 0.05 to 2 mol%, and if it is less than 0.01 mol%, a stable aqueous dispersion may not be obtained. If it exceeds 10 mol%, the polymerization reaction apparatus becomes dirty. It is not preferable in terms of storage stability and size effect of the aqueous dispersion.

The anionic (meth) acrylamide copolymer thus obtained is an aqueous solution or an aqueous dispersion, and the organic solvent used in the polymerization may remain partially. The viscosity is 10 to 5000 centipoise in a 20% by weight aqueous solution (however, a value measured at 25 ° C. at 60 revolutions per minute by a Brookfield viscometer).
Are preferable, and those having the above viscosity of 50 to 1000 centipoise are more preferable. When the viscosity is out of the above range, the dispersibility of the rosin-based material is poor, so it is necessary to use a large amount of the dispersant, resulting in poor sizing performance, or storage stability of the sizing agent prepared using the same. Stability and mechanical stability tend to be poor.

The dispersant (E) may be used in combination with at least one of other neutral or anionic synthetic high molecular compounds, natural high molecular compounds, derivatives thereof and protective colloids. Also functions as a polymeric surfactant having a hydrophobic group, a nonionic group and / or an ionic group. As the synthetic polymer compound, for example, a partially or completely neutralized product of an anionic styrene / (meth) acrylic acid-based copolymer and an anionic (meth) acrylate-based copolymer can be exemplified. Examples of the natural polymer compound or its derivative include corn starch, tapioca starch, potato starch and the like. These polymer compounds may be used alone or as a protective colloid.
A combination of more than one species may be used.

In the present invention, the dispersant (F) contains at least one kind of (meth) acrylamide copolymer, which may be any of anionic, cationic, amphoteric and nonionic. Any two or more of them can be used in combination. As a cationic (meth) acrylamide copolymer, as a cationic monomer,
Monoalkylamino (hydroxy) alkyl (meth) acrylate (refers to a substance composed of all combinations of those with or without parentheses, the same applies hereinafter), dialkylamino (hydroxy) alkyl (meth) acrylate, monoalkylamino Alkyl (meth) acrylamide, dialkylaminoalkyl (meth) acrylamide, vinylpyridine, vinylimidazole, diallylamine, etc.
Copolymers obtained by copolymerizing at least one other quaternary ammonium salt with (meth) acrylamide, if necessary, together with another nonionic vinyl monomer such as a hydrophobic monomer described below.

As the anionic (meth) acrylamide copolymer, an anionic monomer may be used.
Monomers having a carboxylic acid group such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, vinylsulfonic acid, (meth) allylsulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid , A monomer having a sulfonic acid group such as sulfonated styrene, a monomer having a phosphoric acid ester group such as a phosphoric acid ester of hydroxyalkyl (meth) acrylate, and at least one of alkali metal salts and ammonium salts of these acids. Accordingly, a copolymer obtained by copolymerizing (meth) acrylamide with another nonionic vinyl monomer such as a hydrophobic monomer described below may be used.

The amphoteric (meth) acrylamide copolymer includes the above-mentioned cationic monomer and anionic monomer and, if necessary, other nonionic vinyl monomers such as a hydrophobic monomer (described later). ) Copolymers copolymerized with acrylamide. Also,
Nonionic (meth) acrylamide copolymers include, as hydrophobic monomers, styrene, styrene derivatives, alkyl (meth) acrylates, (meth) acrylonitrile, vinyl esters such as vinyl acetate, vinyl propionate, vinyl ethers, and the like. And copolymers of (meth) acrylamide with at least one of other nonionic vinyl monomers as necessary.

In order to synthesize the above (meth) acrylamide copolymer, conventionally known methods such as solution polymerization, emulsion polymerization, dispersion polymerization and precipitation polymerization can be applied. For example,
In the case of solution polymerization, the vinyl monomer is mixed with a lower alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol or tertiary butyl alcohol, an organic solvent such as acetone, methyl ethyl ketone or dioxane, or a mixture of these organic solvents and water. It is obtained by polymerizing in a liquid with a radical polymerization catalyst and distilling off the organic solvent after completion of the polymerization. At this time, the copolymer formed during the polymerization may be insolubilized and precipitate (precipitation polymerization). At that time, a dispersion stabilizer such as polyvinyl alcohol or a (meth) acrylic acid (co) polymer is previously added to the polymerization system. (Dispersion polymerization). In the case of emulsion polymerization, the above monomer is dispersed in water in the presence of a known anionic and / or nonionic surfactant, and polymerized by a radical polymerization catalyst. In this case, emulsifier-free emulsion polymerization without adding a surfactant is also possible.

The obtained anionic (meth) acrylamide copolymer may be converted into a salt with a cationic monomer unit or an anionic monomer unit, if necessary.
A copolymer may be obtained by using a salt type cationic monomer or an anionic monomer. This salt can be neutralized to form a salt during or after the copolymerization reaction of a reaction system using a cationic monomer or an anionic monomer.

Examples of the radical polymerization catalyst include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate; redox polymerization catalysts obtained by combining these persulfates with a reducing agent; and 2,2'-azobis An azo catalyst such as isobutyronitrile can be used. Also, in order to adjust the molecular weight of the copolymer, a known chain of alkyl mercaptans, thioglycolic acid or its esters, mercaptopropionic acid or its esters, mercaptoethanol, thioglycol, carbon tetrachloride, etc., if necessary. A transfer agent can be appropriately used in combination.

The alkyl mercaptans are preferably alkyl mercaptans having 6 to 22 carbon atoms, for example, n-octyl mercaptan and n-dodecyl mercaptan.
0.01 to 10 mol% based on the total amount of monomers in the reaction system,
Most preferably, it is 0.05 to 2 mol%, and if it is less than 0.01 mol%, a stable aqueous dispersion may not be obtained. If it exceeds 10 mol%, the polymerization reaction apparatus becomes dirty. It is not preferable in terms of storage stability and size effect of the aqueous dispersion.

The above (meth) acrylamide copolymer thus obtained is an aqueous solution or an aqueous dispersion, and the organic solvent used at the time of polymerization may remain partially. The viscosity is 10 to 50 in a 20% by weight aqueous solution.
Those having a viscosity of 00 centipoise (measured by a Brookfield viscometer at 25 ° C. at 60 rotations per minute) are preferable, and those having the above viscosity of 50 to 1000 centipoise are more preferable. When this viscosity is outside the above range
Since the dispersibility to Ke Tendaima such poor, it is necessary to increase the amount of the dispersing agent, or the result as the size inferior performance or storage stability stability of sizing agent prepared by using the same, mechanical stability Tends to be inferior.

The dispersant (F) may be used in combination with at least one of other synthetic polymer compounds, natural polymer compounds, derivatives thereof and protective colloids. It also functions as a polymer surfactant having a nonionic group and / or an ionic group. As the synthetic polymer compound, for example, a partially or completely neutralized product of an anionic styrene / (meth) acrylic acid-based copolymer and an anionic (meth) acrylate-based copolymer can be exemplified. Examples of the natural polymer compound or a derivative thereof include various cationized starches obtained by cationizing corn starch, tapioca starch, potato starch and the like with a tertiary or quaternizing agent. These polymer compounds may be used alone or in combination of two or more as protective colloids.

Various low molecular surfactants can be used in combination with the dispersants (E) and (F). Low molecular surfactants include rosin alkali metal salts, fortified rosin alkali metal salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxyethylene sulfeniether salts, Polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene styryl phenyl ether sulfate, alkyl sulfate, naphthalene sulfonate formalin condensate, polyoxyethylene alkyl ether sulfosuccinate Ester salt, polyoxyethylene alkyl phenyl ether sulfosuccinic acid monoester salt, polyoxyethylene monostyryl phenyl ether sulfosuccinic acid monoester Anionic surfactants such as ester salts, polyoxyethylene distyryl phenyl ether sulfosuccinate monoester salts, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene styryl phenyl ether, polyoxypropylene polyoxyethylene glycol Nonionic interfaces such as glycerin fatty acid ester, sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, pentaerythritol fatty acid ester, propylene glycol fatty acid ester, fatty acid diethanolamide, polyoxypropylene polyethylene glycol, etc. Examples of the dispersant (F) include a surfactant. Le ammonium chloride, trialkyl benzyl ammonium chloride, alkyl amines, can be exemplified cationic surfactant polyoxyethylene alkyl amines.

The method for producing a neutral papermaking sizing agent of the present invention is prepared by mixing an aqueous dispersion and the aqueous dispersion of Ke Tendaima such rosin-based material, each of the aqueous dispersion in the following manner To manufacture. The method for producing the aqueous dispersion of the rosin-based material is not particularly limited, but is a known method, for example, as described in JP-B-54-36242, the rosin-based material of the above-mentioned component (A). Is dissolved in an oil-soluble solvent in advance, and the above-mentioned component (E) and water are mixed and treated with a homogenizer, followed by distilling off the solvent, as described in the so-called solvent method, JP-B-53-32380. the melted above (a) rosin material components to produce an oil-in-water Emar tion through mixing the above-mentioned [E] component and water present invention under high pressure homogenizer, a so-called mechanical method or JP, 54─77209
As described in JP-melted above (A) the [E] component and a part of water were mixed under stirring the water-in-oil and of the present invention to rosin-based material of component Emar tion is formed and further by adding water phase transition to an oil-in-water Emar tion,
A so-called phase inversion method is used. The dispersant (E)
The above-mentioned low molecular surfactant is used in combination as needed.

The aqueous dispersion thus obtained has a total solid content of 20 to 60% by weight, preferably 30 to 50% by weight, and the average particle size of the emulsion particles (cumulative 50% size in the weight-based particle size distribution). Is 1 μm or less, preferably 0.1 μm.
5 μm or less. When the average particle diameter exceeds the particle diameter of 1 μm, a precipitate tends to be formed during storage, and mechanical stability tends to be poor. Master 50% diameter is Master
It was measured with a Sizer (Malvern). The pH of the aqueous dispersion is from 2.5 to 6.5.

[0038] Aqueous dispersions containing Ke Tendaima are for example the general formula (1) ketene dimer compounds at a temperature above the melting point of the ketene dimer compound represented by the above dispersing agent (F) and the aqueous medium And uniformly dispersed by an emulsifier such as a homomixer, a high-pressure discharge homogenizer, and an ultrasonic emulsifier. In addition, the above-mentioned low molecular surfactant is used in combination with the dispersant (F) as necessary.

[0039] While for neutral papermaking sizing agent in the aqueous dispersion (D) is mixed with the present invention the aqueous dispersion (B) and Ke Tendaima compound (C) of the rosin-based material (A) is obtained,
The mixing ratio of the (A) :( C) 99: 1~65: a 35, rosin-based material is 65 wt% or more, Ke Tendaima are preferable is 35 wt% or less, pulp of this field Goke Tendaima acids The amount added to the slurry is 0.01 to 0.1.
It is preferable to mix them so as to be 1% by weight (based on solid content of pulp) to obtain the desired size effect, but it is not limited thereto . Ke Tendaima class is 0.01% by weight
When (pulp solids) less than, desired effect due to the mixing process the Ke Tendaima compound is not remarkable,
Further, if it is 35 wt% more or 0.1% by weight (pulp solids) or more, it may be the problem that arises when using the Quai Tendaima such as sizing agent occurs.

The mixing of the aqueous dispersion of aqueous dispersions and Ke Tendaima such the rosin-based material, a homomixer as rosin material and Ke Tendaima compound is the ratio of the homogeneity using a static mixer or a homogenizer And then removing the coarse particles through a strainer or a back filter. The sizing agent for neutral papermaking thus obtained has a particle size of the dispersed phase of about 1 μm or less, and has very good storage stability and mechanical stability. In the case of a high-speed paper machine, the drying conditions must be mild, but under such drying conditions the papermaking pH is in the neutral to weakly alkaline region, particularly paper made from waste paper mixed with calcium carbonate. In a papermaking system or a papermaking system using calcium carbonate as a filler, there is an advantage that it can be used as it is or diluted, and adjustment from a weak size to a strong size is possible.

The sizing agent for neutral papermaking according to the present invention is a sizing agent comprising an aqueous dispersion in which a rosin ester and an alkyl ketene dimer described in JP-B-59-51637 are dispersed with a cationized starch or the like. The sizing effect is more excellent, and particularly when a fortified rosin ester is used as a rosin-based substance, a more remarkable sizing effect is exhibited.

In the sizing method of the present invention, the neutralizing papermaking sizing agent obtained above is added, for example, to the wet end portion in the process of producing paper or paperboard. Specifically, the pulp slurry has a dry weight of 0.05 to
5% by weight of solid content, preferably 0.1 to 3% by weight of solid content is added. However, this time is added Luque Tendaima compound is preferably in the range of 0.02 to 0.1 wt%. The pH of the pulp slurry at the time of the addition is 6.5 to 9.
Although it is preferably used in the neutral or alkaline region of 0, it is also used in other regions, and an appropriate amount of a sulfate band can be used in combination.

In the production of paper or paperboard, pulp raw materials include bleached or unbleached chemical pulp such as kraft pulp or sulfite pulp, bleached or unbleached chemical pulp, mechanical pulp, thermomechanical pulp, or the like. Any of used paper pulp, such as used newspaper, used magazine, used corrugated paper, and used deinked paper, can be used. Also, a mixture of the pulp raw material and synthetic fibers such as asbestos, polyamide, polyimide, polyester, and polyolefin can be used.

Additives such as a filler, a dye, a dry paper strength improver, a wet strength improver, a retention improver, and a drainage improver are also required to exhibit the physical properties required for each paper type. You may use it according to. As the filler, heavy or light calcium carbonate is mainly used, but clay and talc are also used, and these may be used in combination. Examples of the dry paper strength improver include anionic polyacrylamide, cationic polyacrylamide, amphoteric polyacrylamide, and cationized starch, and these may be used alone or in combination. Examples of the wet paper strength improver include polyamide / epichlorohydrin resins, and these may be used alone or in combination with anionic polyacrylamide. Examples of the retention aid include anionic or cationic high molecular weight polyacrylamide, a combination of silica sol and cationized starch, and a combination of bentonite and cationic high molecular weight polyacrylamide. Examples of the drainage improver include polyethyleneimine, cationic or anionic polyacrylamide, and the like. Further, starch, polyvinyl alcohol, dye, coating color, surface sizing agent, anti-slip agent and the like may be applied as required by a size press, a gate roll coater, a bill blade coater, a calender or the like. In addition, bansulfate may be used before, after or simultaneously with the addition of the sizing agent of the present invention.

The sizing method according to the present invention is used in the following papermaking systems. Papermaking systems in which bansulfate cannot be used or whose usage is limited to small amounts, such as neutral pure white roll paper, neutral liners, rust-proof liners, and metal interleaving papermaking systems in which calcium carbonate is mixed from waste paper raw materials, such as gypsum Base paper, white board, coated base paper, medium paper, general liner, and papermaking system using calcium carbonate as a core filler, such as neutral printing writing paper, neutral coated base paper, neutral PPC paper, neutral thermosensitive paper, medium Pressure-sensitive base paper, neutral inkjet paper, and neutral information paper A papermaking system in which the amount of the fixing agent used is limited, for example, kraft paper. A sizing method using a neutral papermaking sizing agent according to the present invention is a conventional neutral sizing. Method, for example, a sizing method using a sizing agent containing alkyl ketene dimer, alkenyl succinic anhydride or rosin ester as a main component. In particular, there are advantages such as excellent sizing effect on pulp containing high-yield pulp, rapid rise of size, and less contamination of papermaking tools such as press rolls and dryer campuses.

[0046]

The following (A), (B), (E), (F)
The present invention will be described more specifically with reference to production examples of components, examples using the components, and comparative examples, but the present invention is not limited to these examples. In addition, in each example, all parts and% are based on weight unless otherwise specified.

Production of rosin-based substance (A) # 1 Production of rosin esters (A-1) to (A # 5) 1 l of a rosin ester equipped with a stirrer, a thermometer, a nitrogen inlet tube, a water separator and a cooler In a flask, 600 parts of gum rosin having an acid value of 170 and 55 parts of glycerin (preparation molar ratio ─COOH / ─OH)
= 1.0) and heated to 270 ° C. under a nitrogen stream,
The reaction was carried out at the same temperature for 15 hours to obtain a rosin esterified product of (A-1). Assuming that the acid value of the obtained esterified product is 17 and this is due to gum rosin having an acid value of 170, the content of unreacted gum rosin in the esterified product is about 10%, and the rosin contained in the esterified product is approximately 10%. The glycerin ester content is calculated to be about 90%. Hereinafter, the ester content in the esterified product was calculated according to this.

In the same manner as described above, rosin esters (A─) were obtained by changing the rosin esters shown in Table 1 below and the esterified products of trihydric to tetrahydric alcohols by changing their types and charging ratios.
2) to (A # 5) were produced.

[0049]

[Table 1]

{2} Preparation of fortified rosin ester {2} 1 Fumaric acid fortified rosin ester (A-
Preparation of 6) 455 parts of the esterified product (A-1) of gum rosin and glycerin obtained in # 1 was heated to 200 ° C., melted, 45 parts of fumaric acid was added, and the mixture was heated and kept at the same temperature for 3 hours. A rosin ester fumaric acid fortified product (A # 6) was obtained.

{2} 2 Preparation of maleic anhydride fortified rosin ester (A-7) 455 parts of esterified product (A-1) of gum rosin and glycerin obtained in # 1 was heated to 180 ° C. and dissolved. Thereafter, 45 parts of maleic anhydride was added, and the mixture was added at 200 ° C for 3 hours.
The mixture was heated and maintained for a period of time to obtain a maleic acid fortified rosin ester (A-7).

Production of Enriched (2-8) Rosin Esters (A-8) to (A-11) Table 2 shows the types of rosin esters, α, β} unsaturated carboxylic acids and their charging ratios. $ 2 above according to the numerical value
Α, β of rosin esters in the same manner as in the production method of
強化 Unsaturated carboxylic acid fortified products (A-8) to (A─11)
Was manufactured.

{2} 4 Production of Gum Rosin Fumaric Acid Fortified Material (A-12) 465 parts of gum rosin was heated to 200 ° C. and melted.
35 parts of fumaric acid was added, and the mixture was heated and maintained at the same temperature for 3 hours to obtain a fumaric acid fortified gum rosin (A-12). The fortification degree (addition rate of fumaric acid) of this fortified material was 7%.

[0054]

[Table 2]

Production of Dispersant (E) for Rosin-Based Substance # 1 Production of Anionic Copolymer Solution (E-1) Four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube In addition, n-butyl methacrylate 10
Parts, 12.5 parts of an 80% aqueous acrylic acid solution, 120 parts of a 50% aqueous acrylamide solution, 48 parts of a 50% aqueous methacrylamide solution, 62.3 parts of ion-exchanged water, 163.2 parts of isopropyl alcohol, and 2 parts of n-dodecyl mercaptan. The mixture was heated to 60 ° C. under a nitrogen gas atmosphere while stirring. AIBN as a polymerization initiator
(Azoisobutyronitrile) (0.2 part) was added, the temperature was raised to 80 ° C., and the mixture was maintained for 3 hours. 65 parts of ion-exchanged water were added, and then isopropyl alcohol was distilled off. After the completion of the distillation, the solid content concentration was further increased by ion exchange.
An anionic copolymer solution (E-1) having a 5% viscosity of 22.3 centipoise (cps) was prepared. The viscosity was measured using a Brookfield viscometer at 25 ° C. and 60 revolutions per minute (hereinafter the viscosity measurement conditions are the same).

# 2 Anionic copolymer solution (E-
Production of 2) Iso-butyl methacrylate 3 was placed in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube.
4 parts, 25 parts of methacrylic acid, 5 parts of styrene, 5 parts of sodium styrenesulfonate, 30 parts of a 50% acrylamide aqueous solution, 41 parts of ion-exchanged water, 164 parts of isopropyl alcohol, and 2.5 parts of n-dodecyl mercaptan were charged. While stirring this mixture under a nitrogen gas atmosphere,
The temperature was raised to 60 ° C. 0.1 parts of AIBN (azoisobutyronitrile) was added as a polymerization initiator, and the temperature was raised to 80 ° C. and maintained for 4 hours. 82 parts of ion-exchanged water were added, and then isopropyl alcohol was distilled off. After completion of the distillation, ion-exchanged water and 37 parts of a 30% aqueous sodium hydroxide solution were added to produce an anionic copolymer solution (E-2) having a solid content of 20.8% and a viscosity of 110.5 cps.

Production of aqueous dispersion of rosin-based substance # 1 Production of aqueous dispersion of rosin-based substance (B-1) 150 parts of maleic acid fortified rosin ester (A # 7) obtained in above {2} 2 Is heated and melted at about 150 ° C., and while stirring vigorously, 10.5 parts of the anionic acrylamide copolymer solution (E # 1) obtained in # 1 (in terms of solid content)
Into a water-in-oil emulsion, and then quickly add hot water to this to form a stable oil-in-water emulsion, and then quickly add hot water to form a stable oil-in-water emulsion. And cooled to room temperature. The emulsion thus obtained has a solids content of 45.5% and a viscosity of 2
It is 5.6 cps, and the cumulative 50% diameter (hereinafter referred to as an average particle diameter) in the weight-based particle size distribution measured by a Master Sizer (manufactured by Malvern Co., Ltd.) is 0.32.
μ, which was stable for a long time.

# 2 Aqueous dispersion of rosin-based substance (B-
Production of 2) 150 parts of maleic acid fortified rosin ester (A # 7) obtained in the above {2-2} was dissolved in 150 parts of toluene,
Anionic copolymer solution obtained in # 2 (E # 2) 10.5
Parts (in terms of solid content) and 220 parts of water were mixed. The mixture was passed twice through an industrial homogenizer at a pressure of about 150 Kg / cm ² , after which all toluene was distilled off under reduced pressure. The thus-obtained emulsion had a solid content of 35.2%, a viscosity of 15.8 cps, an average particle diameter of 0.38 μm, and was stable for a long time.

# 3 An aqueous dispersion of a rosin-based substance (B-
Production of 3) 150 parts of the rosin ester fumaric acid fortified product (A # 7) obtained in the above {2} 2 was heated and melted at about 150 ° C., and the vigorously stirred anionic copolymer obtained in the above # 1 was obtained. 10.5 parts of the solution (E─1) (in terms of solid content) and 200 parts of water were mixed under high temperature and high pressure, and the mixture was 155 kg / cm ^2.
Through an industrial homogenizer twice at a pressure of. The solids content of the emulsion thus obtained is 44.9.
%, The viscosity is 20.5 cps, and the average particle size is 0.4.
1 μ, which was stable for a long time.

# 4 Aqueous dispersion of rosin-based material (B-
4) Production of (B-11) Table 3 shows the types and charging ratios of rosin esters, fortified rosin esters, fumaric acid fortified gum rosin and anionic copolymer solutions, and low molecular weight surfactants. According to the obtained values, aqueous dispersions (B-4) to (B-11) of the rosin-based substance were produced in the same manner as in the production method of # 1 above.

[0061]

[Table 3]

[0062] Production ─1─1 cationic copolymer aqueous dispersion of Ke Tendaima compound (D) solution (F─1) of a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube 4 After 6 parts of dimethylaminoethyl methacrylate, 192 parts of a 50% aqueous acrylamide solution, 8.1 parts of isopropyl alcohol and 285 parts of water are added to a one-necked flask, the pH is adjusted to 4.0 to 4.5 with a 15% aqueous sulfuric acid solution. After the adjustment, oxygen in the reaction system was removed with nitrogen gas. Then, while stirring, 9.6 parts of a 5% aqueous ammonium persulfate solution and 1.6% of a 5% aqueous sodium sulfite solution were used as polymerization initiators.
After charging the part, the temperature was raised from room temperature to 75 ° C. in 30 minutes, and the temperature was maintained at the same temperature for 3 hours. The resulting cationic copolymer solution (F-1) had a solid content of 20.4%, a viscosity of 152 cps, and a pH of 4.5.

{1} 2 Anionic polymer solution (F-
Preparation of 2) 5 parts of styrenesulfonic acid, 2 parts of itaconic acid, 186 parts of a 50% aqueous acrylamide solution, 6.4 parts of isopropyl alcohol in a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. And 290 parts of water, the pH was adjusted to 4.0 to 4.5 with a 10% aqueous sulfuric acid solution, and oxygen in the reaction system was removed with nitrogen gas. Then, while stirring, 9.6 parts of a 5% aqueous ammonium persulfate solution and 1.6% of a 5% aqueous sodium sulfite solution were used as polymerization initiators.
After charging the part, the temperature was raised from room temperature to 75 ° C. in 30 minutes, and the temperature was maintained at the same temperature for 3 hours. The solid content of the obtained anionic copolymer solution (F-2) was 20.8%, the viscosity was 179 cps, and the pH was 4.3.

[0064] ─2 Ke Tendaima such aqueous dispersion (D-1) obtained in Preparation 85 parts of water and the ─1 cationic copolymer solution (F-1) 20 parts (solid content) and lignin 4 parts of sodium sulfonate are mixed and the pH of this mixture is 3.5
After adjusting the temperature with a 15% aqueous sulfuric acid solution and raising the temperature to 70 ° C,
Alkyl ketene dimer (C-1) (having a raw material fatty acid composition of 16 carbon atoms: 40:60 having 18 carbon atoms)
Was added to this mixture, and the mixture was stirred to perform preliminary emulsification. This pre-emulsion was homogenized by passing once through a homogenizer at 70 ° C under a pressure of 4000 psi. The solid content was diluted with water to 30%, and further adjusted to pH 4.5 with acetic acid to obtain an aqueous dispersion (D-1) of an alkyl ketene dimer. Its solids content is 30.
8%.

[0065] In the production ─2 of ─3 Ke Tendaima such an aqueous dispersion of (D-2), use instead of the anionic copolymer solution (F-2) of the cationic copolymer solution (F-1) An aqueous dispersion (D-2) of an alkyl ketene dimer was obtained in the same manner except that the above procedure was repeated. Its solids content was 30.8%.

[0066] ─4 aqueous dispersion of Ke Tendaima acids in the production ─2 of (D-3), cationic starch (nitrogen content 0.4% instead of the cationic copolymer solution (F-1), 10 %
The same amount (solid content) of an aqueous solution viscosity of 30 cps), alkyl ketene dimer (C-2) (the raw material fatty acid composition of which has 16 carbon atoms: the one having 18 carbon atoms has 5:95)
Was used in the same manner as above to obtain an aqueous dispersion of an alkyl ketene dimer (D-3). Its solids content is 3
0.2%.

Production of Sizing Agent # 1 Production of Neutral Papermaking Sizing Agent (G) (Example) Each aqueous dispersion obtained above was mixed with a rosin-based material and an alkyl ketene dimer in a mixing ratio (rosin-based After mixing so that the weight ratio of the substance to the alkyl ketene dimer) is as shown in Table 4, water was added so that the solid content became 30%, and the mixture was homogenized through a static mixer, and further coarse particles were removed through a bag filter. Thus, neutral papermaking sizing agents G-1 to G-16 were obtained.

[0068]

[Table 4]

(2) Production of sizing agent for comparative example (2) Aqueous dispersion of alkyl ketene dimer (D
Preparation of -4) 50 parts by weight of a 30:70 mixture of a rosin ester (A-1) and an alkyl ketene dimer (C-1) were mixed by heating, and the mixture was cationized starch (nitrogen content 0.4%, 10%).
125 parts of a 10% aqueous solution having an aqueous solution viscosity of 30 cps) and 290 parts of water are added, and 4 parts of sodium ligninsulfonate are mixed. The pH of the mixture is adjusted to 3.5 with a 15% aqueous sulfuric acid solution, and the temperature is raised to 70 ° C. After that, the mixture was stirred to carry out preliminary emulsification. This pre-emulsion is added to a homogenizer at 70 ° C for 4 hours.
One pass under 2,000 psi pressure homogenized. A
Alkyl Ketendaima over the solid was diluted with water to a 15% to obtain an aqueous dispersion of alkyl ketene dimer (D-4) was adjusted to pH4.5 further with acetic acid.

{2} 2 Sizing agent for neutral papermaking (G-1
Production of 7) The aqueous dispersion (B-11) of the rosin fortified product and the aqueous dispersion (D-4) of the alkyl ketene dimer were mixed at a mixing ratio (weight ratio) of the rosin fortified product and the alkyl ketene dimer of 8.
After mixing to give a ratio of 0:20, water was added so that the solid content was 30%, and the mixture was homogenized through a static mixer. Further, a coarse paper particle was removed through a back filter to remove neutral particles (G-17). I got

Applied Tests Tables 5, 6, and 7 show the results of a size effect test and a slip angle test performed using the sizing agents obtained in the above Examples and Comparative Examples under the following test conditions. In addition, all the added chemicals in the table are shown by the solid content weight ratio to the absolute dry weight of the pulp. ─1 Sizing agent effect test, slip angle test bleached kraft pulp (softwood to hardwood pulp ratio is 1: 4
The mixed pulp) was diluted with diluting water having a hardness of 100 ppm so as to have a pulp concentration of 2.5%, and beaten to a Canadian standard freeness of 350 ml using a beater. 1.2 liters of this pulp slurry was weighed into a disintegrator and light calcium carbonate 20%, bansulfate 0.5
%, Cationized starch 0.8%, and sizing agents of the above Examples and Comparative Examples were added in predetermined amounts, and then diluted to a concentration of 0.25% with diluting water having a pH of 8.0, and then cationic polyacrylamide was used as a fixing agent. Was added to 0.02%, and paper was made using a Noble and Wood paper machine, and the basis weight was 67 g / m ² (ash content in the paper was 1).
4%). Drying of the wet paper was performed under a predetermined drying condition using a drum dryer. After the obtained test paper was conditioned for 24 hours in a constant temperature and constant humidity environment (20 ° C., 60% relative humidity), the sizing degree was measured by the Steicht method. The slip angle test was performed by a tilt method (Japan Tappi No. 3).
1─79). Table 5 shows the measurement results.

[0072]

[Table 5]

# 2 Size effect test bleached kraft pulp (softwood to hardwood pulp ratio is 1: 4
The mixed pulp) was diluted with diluting water having a hardness of 100 ppm so as to have a pulp concentration of 2.5%, and beaten to a Canadian standard freeness of 350 ml using a beater. 1.2 liters of this pulp slurry was weighed into a disintegrator and light calcium carbonate 7%, bansulfate 0.5
%, Cationized starch 0.5%, the sizing agents of the above Examples and Comparative Examples were added in predetermined amounts, and then diluted to a concentration of 0.25% with dilute water having a pH of 8.0, and then cationic polyacrylamide was used as a fixing agent. Was added to 0.02%, and the paper was made with a Noble and Wood paper machine, and the basis weight was 64 g / m ² (ash content 5 in paper).
%) Test paper was obtained. Drying of the wet paper was performed under a predetermined drying condition using a drum dryer. After the obtained test paper was conditioned for 24 hours in a constant temperature and constant humidity environment (20 ° C., 60% relative humidity), the sizing degree was measured by the Steicht method. This sizing agent effect test was carried out in a papermaking system using calcium carbonate as a filler, for example, neutral printing writing paper, neutral coated paper, neutral PPC paper, neutral heat-sensitive base paper, neutral pressure-sensitive base paper,
This corresponds to the conditions for making neutral ink-jet paper and neutral information paper.

[0074]

[Table 6]

[0075]

[Table 7]

[0076]

As described above, the neutral paper sizing agent obtained by the method for producing a neutral paper sizing agent of the present invention comprises:
In addition to being able to improve the point of soiling of the paper machine when using a ketene dimer-based sizing agent and the slipperiness of paper by the combined use of a rosin-based sizing agent containing at least one of rosin esters and its reinforcing material, The sizing effect can be further improved as compared with a sizing agent obtained by simultaneously dispersing ketene dimer and rosin ester in water.
Further, the aqueous dispersion also rosin material manufacturing method, an aqueous dispersion of ketene dimers and rosin-based material Ketendai
The rosin-based material and the ketene dimer are mixed according to the required sizing degree, since they are mixed so that the weight ratio of the mers is 99: 1 to 65:35. Kind of
It can be set arbitrarily within the range of the weight ratio . In addition, since each aqueous dispersion can be stored relatively more stably than a mixture of the two, when necessary, both can be stored with the above-mentioned rosin-based material and ketene.
A sizing agent which does not impair the dispersion stability can be obtained by mixing the dimers within the range of the weight ratio . At this time, each aqueous dispersion and its mixture are particularly anionic (meth)
It is well stabilized by the acrylamide copolymer dispersant. The resulting sizing paper has a good size effect and a high sizing performance.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-6680 (JP, A) JP-A-55-132799 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 11/00-27/42

Claims (12)

(57) [Claims] At least one of rosins and their fortified products
An aqueous dispersion (B) containing a rosin-based substance (A) containing at least one of a rosin ester and a fortified product thereof, which is a reaction product of a seed with an alcohol, and a ketene dimer (C). A method for producing a neutral papermaking sizing agent obtained by mixing an aqueous dispersion (D) containing
Weight ratio of rosin-based substance (A) to ketene dimer (C)
(A): A method for producing a neutral papermaking sizing agent wherein (C) is 99: 1 to 65:35 . 2. A method for producing rosin esters rosins and trihydric alcohols and tetravalent alcohols of at least one alcohol and the ester is a claim 1 Symbol placing neutral papermaking sizing agents. 3. The aqueous dispersion (B) is a rosin-based substance (A)
And a dispersant (E) containing at least one of an acrylamide-based copolymer, a methacrylamide-based copolymer, an acrylamide-methacrylamide-based copolymer and an anionic copolymer composed of a salt thereof, and The above (A)
The method for producing a neutral papermaking sizing agent according to claim 1 or 2 , which is an aqueous dispersion in which the components are dispersed in water by the component (E). 4. A dispersant (E) comprising at least one of an acrylamide-based copolymer, a methacrylamide-based copolymer, an acrylamide-methacrylamide-based copolymer and an anionic copolymer comprising a salt thereof, The method for producing a neutral papermaking sizing agent according to claim 3, wherein a molecular surfactant is used in combination. 5. The aqueous dispersion (D) contains a ketene dimer (C) and at least one of an acrylamide-based copolymer, a methacrylamide-based copolymer, an acrylamide-methacrylamide-based copolymer and a salt thereof. An aqueous dispersion containing the dispersant (F), and the component (C) dispersed in water by the component (F).
5. The method for producing a sizing agent for neutral papermaking according to any one of 4 . 6. A dispersant (F) comprising at least one of an acrylamide copolymer, a methacrylamide copolymer, an acrylamide-methacrylamide copolymer and a salt thereof, and a low molecular surfactant. The method for producing a neutral papermaking sizing agent according to claim 5 . 7. A dispersing agent (F) are provided methods for producing the neutral papermaking sizing agent according to claim 5 or 6 is an anionic copolymer. 8. A neutral papermaking sizing agent produced by the method according to any one of claims 1 to 7 . 9. A sizing method in which the sizing agent for neutral papermaking according to claim 8 is added to a pulp slurry in a neutral to alkaline pH range of 6.5 to 9.0. 10. The sizing method according to claim 9 , wherein calcium carbonate is used as the filler. 11. A sizing paper obtained using the neutralizing paper sizing agent according to claim 8 . 12. A sizing paper obtained by using the sizing agent for neutral papermaking according to claim 8 and calcium carbonate.