JP3240735B2 - Papermaking sizing composition and method for producing paper using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sizing composition for papermaking. More specifically, using a specific copolymer, a ketene dimer compound is dispersed,
The present invention relates to a sizing composition for papermaking having an excellent sizing effect. The present invention also relates to a method for producing paper using such a sizing composition.

[0002]

2. Description of the Related Art Alkaline soap rosin sizing agents have been widely used as sizing agents for internal addition. Recently, inexpensive calcium carbonate and the like have been used as fillers to form paper in a neutral or alkaline region. The so-called neutral papermaking has been widely performed. The alkali soap type rosin-based sizing agent does not show sufficient effects in this neutral papermaking, and has a problem. Instead of this, various neutral sizing agents for internal use that can be used in neutral systems have been proposed, but among them, a size in which a ketene dimer compound such as an alkyl ketene dimer is dispersed in water. Agents are frequently used because they are easy to use in handling.

[0003]

The ketene dimer compound is effective in a wide pH range and shows a high sizing effect in a small amount. There is a problem that it takes time to develop the effect.

[0004] The time required for the size effect to fully appear is generally expressed by the term "rise of the size effect". In the case of coating, the amount of liquid absorption cannot be controlled, causing problems such as a paper cutting trouble. In order to cover this poor start-up property, it generally responds by increasing the amount of the ketene dimer sizing agent added.However, since the ketene dimer compound itself acts as a wax component, that is, as a lubricant, it is sufficient. However, at the time when the size effect is obtained, that is, in the finished paper, the paper slips on the contrary. Therefore,
It has been desired to develop a ketene dimer sizing composition which promotes the fixation of the ketene dimer compound and promotes the rising property as much as possible.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a copolymer containing a specific cationic monomer as a copolymer component is converted to a ketene dimer compound. The present inventors have found that a sizing composition for papermaking having excellent rising properties can be obtained by using the composition as a dispersant, and the present invention has been accomplished.

That is, the present invention provides a sizing composition for papermaking, which is an aqueous dispersion containing the following two components (A) and (B).

(A) Formula (I)

[0008]

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(Wherein Q ¹ and Q ² each independently represent an aliphatic hydrocarbon group having 8 to 24 carbon atoms or a carbon number of 6 to 24)
And a ketene dimer compound represented by the following formula:

(B) Formula (II)

[0011]

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(Wherein R ¹ and R ² each independently represent hydrogen or methyl, and HX represents an acid) 1 to 99 mol% of a cationic vinyl monomer represented by the following formula: A copolymer containing 1 to 99 mol% of a hydrophilic compound as an essential component.

[0013] The present invention also provides a method for producing paper using the above-mentioned sizing composition.

The ketene dimer compound used in the present invention is
Any of various known ketene dimer compounds represented by the formula (I) can be used. Q ¹ and Q ² in the formula (I) are the same or different hydrocarbon groups, and in the case of an aliphatic hydrocarbon group, are selected from the range of 8 to 24 carbon atoms;
In the case of an aromatic hydrocarbon group, it is selected from the range of 6 to 24 carbon atoms. Aliphatic hydrocarbon groups can be especially alkyl or alkenyl groups, such as octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, and the like, and alkenyl groups include Octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, eicosenyl and the like. The aromatic hydrocarbon group may be an unsubstituted aryl group such as phenyl or naphthyl, an alkyl-substituted aryl group such as octylphenyl or nonylphenyl, or an aralkyl group such as benzyl or phenethyl. . Of these, those in which Q ¹ and Q ² are each an alkyl group are preferred. Such a ketene dimer compound can be used alone or in combination of two or more.

Generally, the ketene dimer compound has the formula (I)
A mixture having a distribution of carbon numbers of Q ¹ and Q ² in
For example, when Q ¹ and Q ² are each an alkyl group,
It is commercially available as a mixture whose carbon number is distributed to some extent. In the present invention, such a commercially available mixture can be used as it is.

The copolymer of the component (B) used for dispersing such a ketene dimer compound is represented by the formula (II):
And a non-ionic compound which is polymerizable with a water-soluble cationic vinyl monomer as an essential component.

The cationic vinyl monomer of the formula (II) is
It is a salt of a secondary amine represented by diallylamine and dimethallylamine. Of these, diallylamine salts are preferably used. In formula (II), represented by HX,
The acid constituting the salt may be any of an inorganic acid and an organic acid,
Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and examples of the organic acid include acetic acid, formic acid, oxalic acid, and propionic acid. Generally, hydrochloric acid, sulfuric acid and the like are preferred. By mixing diallylamine or dimethallylamine with these acids, the formula (I
A cationic vinyl monomer (salt) shown in I) is formed. These cationic vinyl monomers may be used alone or in combination of two or more.

The non-ionic compound, which is another essential component constituting the copolymer of the component (B), is non-ionic, shows water solubility, and is copolymerizable with the cationic vinyl monomer of the formula (II). Any organic compound may be used, for example, acrylamide, methacrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, polyvinyl alcohol, polyethylene oxide and the like. These nonionic compounds may be used alone or in combination of two or more. Among these, a monomer having a vinyl bond is preferable, and acrylamide or methacrylamide, particularly acrylamide, is particularly preferably used.

In preparing the copolymer of the component (B), the cationic vinyl monomer of the formula (II) and the water-soluble and polymerizable nonionic compound are each 1 to 9%.
Although it is used in the range of 9 mol%, it is preferable to use the cationic vinyl monomer of the formula (II) in a proportion of 5 to 70 mol% and the nonionic compound in a proportion of 30 to 95 mol%.
By copolymerizing only the two components of the cationic vinyl monomer of the formula (II) and the water-soluble, polymerizable nonionic compound, a cationic copolymer is obtained.

In the copolymer of the component (B) used in the present invention, in addition to the above-mentioned essential components, a monomer copolymerizable therewith, especially a vinyl monomer, does not inhibit the water solubility of the copolymer. One or more kinds can be introduced to the extent. Other monomers that can optionally be introduced include, for example, water-insoluble nonionic monomers such as (meth) acrylonitrile, methyl (meth) acrylate, styrene, vinyl acetate, dimethylaminoethyl (meth) acrylate, dimethylamino Propyl (meth) acrylamide or the like, or a quaternary product thereof, a cationic monomer such as dimethylamine or diallyldimethylammonium chloride, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, or an alkali metal salt or ammonium thereof Examples include anionic monomers such as salts, and bifunctional monomers such as ethylene glycol di (meth) acrylate and methylenebis (meth) acrylamide.

The copolymer of the component (B) used in the present invention is:
It can be obtained by copolymerizing the essential copolymerization component as described above or further an arbitrary monomer component. The production of this copolymer can be carried out by a known method, and the polymerization mode is not limited.
Alternatively, the polymerization reaction is preferably carried out in a mixed solvent of water and a water-soluble solvent in the presence of a polymerization initiator.

As the polymerization initiator, those usually used can be used. For example, persulfates such as ammonium persulfate and potassium persulfate, 2,2'-diamidino-2,
Examples include azo compounds such as 2'-azopropane dihydrochloride and azobisisobutyronitrile, and peroxides such as di-t-butyl peroxide, cumene hydroperoxide, and hydrogen peroxide. Known redox initiators, for example, a combination of potassium persulfate and sodium bisulfite or a tertiary amine can also be used. Further, if necessary, known and commonly used chain transfer agents such as isopropyl alcohol and allyl alcohol can be used.

The polymerization is carried out usually at a temperature of 10 to 100 ° C., preferably 40 to 90 ° C., for about 1 to 20 hours. This polymerization can be performed in the presence of oxygen, but is preferably performed in an atmosphere of an inert gas such as nitrogen gas. In the polymerization, the essential components, or monomers that can be copolymerized with these essential components used as necessary, may start the polymerization after charging all of these components collectively, or only certain components, Alternatively, after starting polymerization by charging only a part of all the components, the remaining components may be added continuously or in divided portions to continue the polymerization.

Among the copolymers thus obtained, those having a 15% by weight aqueous solution having a viscosity at 25 ° C. of 5 to 7000 centipoise, especially 2
Those in the range of 0 to 5000 centipoise are preferred.

In the present invention, the copolymer of the component (B) is used in an amount of usually 3 to 250 parts by weight, preferably 5 to 10 parts by weight, based on 100 parts by weight of the ketene dimer compound of the component (A).
It is preferable to use it in the range of 0 parts by weight.

The sizing composition for papermaking of the present invention is obtained by dispersing the ketene dimer compound of the component (A) in water using the copolymer of the component (B) as a dispersant. Mixing and dispersion of both components can be performed by a conventionally known method, for example, using a homomixer, a high-pressure homogenizer, an ultrasonic emulsifier, or the like. In addition, there are no particular restrictions on the addition of a drug, such as a surfactant or a protective colloid, generally used for emulsification, which improves emulsifying power, or a drug added to improve the stability of a product. These can also be used in combination.

When the sizing composition thus obtained is applied to the production of paper, there are no particular restrictions on the timing and method of application. For example, the sizing composition may be added to an aqueous pulp slurry. Either internal sizing for papermaking or so-called surface sizing in which the sizing composition is applied or impregnated after the formation of a paper layer is applicable. The sizing composition of the present invention is particularly suitable for internal sizing to be added to a pulp slurry. In addition,
The paper produced here is in a broad sense and includes paper and paperboard in a narrow sense.

When applied to internal sizing, the sizing composition of the present invention generally has a solid content in the range of 0.01 to 1% by weight, preferably 0.03 to 1% by weight, based on the dry weight of the pulp. A range of 0.5% by weight is added to the pulp slurry. Papermaking itself can be performed according to a usual method. A paper strength enhancer, a drainage enhancer, a retention enhancer, and the like can also be added as necessary, and a filler such as calcium carbonate or talc is usually blended.

[0029]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The percentages in the examples represent% by weight unless otherwise specified.

Embodiment 1

10.7 50% diallylamine hydrochloride aqueous solution
g (0.04 mol) and 144.1 g of ion-exchanged water were charged into a reactor equipped with a stirrer, and the pH was adjusted to 7.0 with a trace amount of a 28% aqueous sodium hydroxide solution. Then, the air in the apparatus was sufficiently replaced with nitrogen gas to make it oxygen-free, and then 0.42 g of ammonium persulfate was added at 70 ° C. Subsequently, while maintaining the internal temperature at 70 ° C., a 50% aqueous acrylamide solution 5
1.2 g (0.36 mol) was added to the reaction system over 2 hours. After that, the reaction was completed by keeping the temperature at 70 ° C. for 2 hours.
An aqueous solution of a cationic copolymer was obtained. From the quantification of the unreacted monomer, the reaction rate was 99% or more. The product had a polymer component of about 15%, a pH of 3.5 and a Brookfield viscosity at 25 ° C of 1200 cps.

On the other hand, Q ¹ and Q in the above formula (I)
² heats the ketene dimer system compound 80g is an alkyl group, as distributed between a few 14 atoms 22 to 70 ° C., this, the copolymer solution 133.3g and water 286.7
g was added and mixed. This was heated to 70 ° C. and preliminarily dispersed by a homomixer for 5 minutes, and then passed once through a high-pressure emulsifier (300 kg / cm ² ) while maintaining the temperature at 70 ° C. to be uniformly dispersed. This was cooled to obtain a sizing composition A for papermaking. This papermaking sizing composition A has a nonvolatile content of 20.1.
%, Viscosity at 25 ° C. was 28.0 cps, and pH was 3.3.

Examples 2 to 4

The polymerization was carried out in the same manner as in Example 1 except that the composition of the cationic copolymer was changed as shown in Table 1. Using the respective copolymers, the same ketene as in Example 1 was used. Dispersing a dimeric compound to form a paper sizing composition B
~ D was obtained. The amount of ammonium persulfate for controlling the viscosity was appropriately changed each time.

Embodiment 5

An aqueous solution of a cationic copolymer was obtained by the same operation as in Example 1, and then 80 g of the same ketene dimer compound used in Example 1 was heated to 70 ° C. 133.3 g of an aqueous solution of the copolymer, 4 g of sodium ligninsulfonate as an emulsifier to be used in combination, and 286.7 g of water were added and mixed. This was heated to 70 ° C. and predispersed for 5 minutes with a homomixer.
While maintaining the temperature at 0 ° C., the mixture was passed once through a high-pressure emulsifier (300 kg / cm ² ) to be uniformly dispersed. This was cooled to obtain a sizing composition E for papermaking. This papermaking sizing composition E comprises:
Non-volatile content 20.2%, viscosity at 25 ° C 26.2 cps, p
H3.3.

[0037]

[Table 1] DAA: diallylamine hydrochloride AM: acrylamide

Comparative Examples 1-4

The polymerization was carried out in the same manner as in Example 1 except that the composition of the cationic copolymer was changed as shown in Table 2, and the same ketene as in Example 1 was obtained using each copolymer. Dispersing a dimeric compound to form a paper sizing composition F
~ I was obtained. The amount of ammonium persulfate for controlling the viscosity was appropriately changed each time.

[0040]

[Table 2] Q-DMEM: quaternary product of dimethylaminoethyl methacrylate with methyl chloride Q-DPMM: quaternary product of dimethylaminopropyl methacrylamide with methyl chloride DADMAC: diallyldimethylammonium chloride DAMA: diallylmethylamine

Embodiment 6

Using the paper sizing compositions A to I obtained in Examples 1 to 5 and Comparative Examples 1 to 4, a size effect test was carried out as follows.

A 0.75% pulp slurry (LBK)
P, Canadian Standard Freeness 410ml)
Then, 10% of heavy calcium carbonate and 0.5% of cationized starch (Kate F, manufactured by Oji National Co., Ltd.) were added as fillers to each of the pulp solids.
5 and paper sizing compositions A obtained in Comparative Examples 1-4
I was added in an amount of 0.15% in terms of solid content, and 0.02% of a cationic polyacrylamide polymer (Percoll 47, manufactured by Allied Colloids) was added as a retention aid. The paper was made to have a basis weight of 60 g / m ² . The obtained wet paper was dehydrated at 4 kg / cm ² for 7 minutes and then dried at 105 ° C. for 30 seconds.

Paper immediately after drying, after drying, at a temperature of 20
The paper was conditioned at 15 ° C. and a relative humidity of 65% for 15 hours, and the paper after the drying was cured at 110 ° C. for 40 minutes, and the degree of Stekigt sizing was measured in accordance with JIS P 8122. . Table 3 shows the results.

[0045]

[Table 3]

[0046]

According to the present invention, a copolymer comprising a specific cationic vinyl monomer and a water-soluble, polymerizable nonionic compound as essential copolymerization components is used as a dispersant for a ketene dimer compound. This makes it possible to obtain a sizing composition for papermaking which is excellent in the rising effect of the size effect.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-258245 (JP, A) JP-A 1-280097 (JP, A) JP-A-60-258244 (JP, A) JP-A 61-258 252398 (JP, A) JP-A-60-99097 (JP, A) JP-A-57-161197 (JP, A) JP-A-63-92799 (JP, A) JP-A-55-137296 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D21H 11/00-27/42

Claims (10)

(57) [Claims] (A) Formula (I) (In the formula, Q ¹ and Q ² are each independently a carbon number of 8 to
24 represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 6 to 24 carbon atoms).
And (B) Formula (II) (Wherein, R ¹ and R ² each independently represent hydrogen or methyl, and HX represents an acid) 1-99 mol% of a cationic vinyl monomer represented by the following formula: A sizing composition for papermaking, which is an aqueous dispersion containing a copolymer containing -99 mol% as an essential component. 2. The composition according to claim 1, wherein Q ¹ and Q ² in the formula (I) are each an alkyl group. 3. The method of claim 2, wherein the cationic vinyl monomer of the formula (II) is
3. The composition according to claim 1, which is a salt of diallylamine. 4. A water-soluble, polymerizable nonionic compound,
2. The acrylamide or methacrylamide of claim 1.
A composition according to any one of claims 1 to 3. 5. The copolymer of component (B) comprises, as essential components, 5 to 70 mol% of a cationic vinyl monomer of the formula (II) and 30 to 95 mol% of a water-soluble and polymerizable nonionic compound. The composition according to claim 1. 6. The composition according to claim 1, wherein the copolymer of component (B) further contains another vinyl monomer as a copolymerization component. 7. The composition according to claim 1, wherein the copolymer of the component (B) has a viscosity of 5 to 7000 centipoise at 25 ° C. when it is a 15% by weight aqueous solution. 8. The ketene dimer compound 100 of the component (A)
The composition according to any one of claims 1 to 7, wherein the copolymer of the component (B) is present in an amount of 3 to 250 parts by weight per part by weight. 9. A method for producing paper, comprising applying the sizing composition according to any one of claims 1 to 8 in any one of papermaking processes. 10. The method according to claim 9, wherein said sizing composition is added to a pulp slurry.