JPH01250499A - Size composition for paper making and method for sizing paper - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a specific ketene dimer based compound and specific polymer in a specified proportion and excellent in storage stability and sizing effects. CONSTITUTION:The objective composition containing (A) 100 pts.wt. ketene dimer based compound expressed by formula I (R1 and R2 are 8-30C hydrocarbon) and (B) 2.5-100 pts.wt., preferably 5-50 pts.wt. polymer obtained by polymerizing a monomer containing >=5mol% monomer expressed by formula II (n is 2-4; R3 is H or methyl: R4-R8 are 1-3C alkyl; X<-> and Y<-> are anion).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a paper sizing composition and a paper sizing method, and more particularly to a ketene dimer-based paper sizing composition with improved storage stability and sizing effect. This invention relates to a paper or paperboard sizing method using the same.

BACKGROUND OF THE INVENTION Conventionally, in paper manufacturing methods for ordinary paper and paperboard, sizing has been carried out to impart functions such as sizeability, waterproofness, and water resistance to these papers. As one of these sizing methods, acid sizing has been carried out in which sizing is performed in an acidic range of p)I 4.5 to 6.5 using a rosin sizing agent having a carboxyl group and a sulfuric acid band. On the other hand, in recent years, efforts have been made to use cheap calcium carbonate as t=i 'l-4, to use waste paper or waste paper containing calcium carbonate, to close the papermaking water, and to give paper permanent shelf life. A so-called neutral sizing method, in which sizing is performed in a neutral to slightly alkaline range of pl+ 6.5 to 9 using a neutral sizing agent, has been attracting attention.

Currently commercially available neutral sizing agents include ketene dimer compounds, substituted cyclic dicarboxylic acid anhydrides, copolymers of cationic monomers and hydrophobic monomers, cationized petroleum resins, and cationized fatty acid amides. However, among these, ketene dimer compounds are often used due to their size effect.

Problems to be Solved by the Invention However, under normal drying conditions in the paper manufacturing process, ketene dimer compounds exhibit a size effect after a certain period of time has passed after drying, but a sufficient size effect is exerted immediately after drying. Not done.

For this reason, in order to improve the surface properties of the paper during the papermaking process, such as penability, slip resistance, smoothness, etc., a water-based processing liquid is applied to the paper using a calender, size press, coater, etc. At this time, the amount of liquid absorbed by the paper increases. In order to control the amount of liquid absorbed so as not to increase, it is necessary to use an excess amount of the ketene dimer compound, which is greater than the amount necessary to exhibit a sufficient size effect over time after drying. Excessive use of ketene dimer compounds is not only economically disadvantageous, but also causes operational problems such as sludge containing ketene dimer compounds on the press rolls and contaminating paper and papermaking equipment. may cause.

Furthermore, conventional ketene dimer compounds have been commercially available and used as aqueous dispersions dispersed in an aqueous continuous phase containing starch, particularly cationized starch. However, ketene dimer compounds inherently tend to react with water, making it difficult to obtain a stable aqueous dispersion. For example, during storage, the dispersion loses its homogeneity, gels, or forms a precipitate. Furthermore, there is a problem in that effects such as sizeability and waterproofness are also reduced. It is even more difficult to obtain particularly highly concentrated and stable aqueous dispersions.

In order to stabilize this aqueous dispersion of a ketene dimer compound, JP-A-60-258244 discloses a method of dispersing a ketene dimer compound in an aqueous continuous phase containing an acrylamide polymer having a cationic group. However, the sizing agent using this method also has the problem that the sizing effect immediately after the paper or paperboard is dried is insufficient.

An object of the present invention is to improve the storage stability and the sizing effect of paper or paperboard immediately after drying in a ketene dimer-based paper sizing composition. Another object of the present invention is to provide a sizing method that does not stain paper manufacturing equipment by using this sizing agent composition for paper manufacturing.

Means for Solving the Problems In order to solve the above problems, the present inventors have made extensive studies and found that (al) a ketene dimer compound represented by the following general formula (1), (wherein R1 , R2 represent the same or different hydrocarbon groups having 8 to 30 carbon atoms. , n is 2.3 or 4, R3 represents a hydrogen atom or a methyl group, R4-R8 are the same or different lower alkyl groups having 1 to 3 carbon atoms, X- and Y- represent the same or different anions ), and contains 2.5 to 100 parts by weight of the polymer b) (per 100 ffi parts of the compound al), or contains 50 parts by weight or less of cationized starch in these,
Furthermore, the size for paper manufacturing is characterized by containing 15 parts by weight or less of an anionic dispersant containing one or more selected from the group consisting of sulfonic acid groups, sulfuric acid ester groups, and salts thereof. The present invention provides a drug composition. In this case, the polymer of fbl is composed of a polymer of 5 to 100 mol% of the monomer of the general formula (n) and 0 to 95 mol% of acrylamide and/or methacrylamide, and a 20% by weight aqueous solution of this polymer is Viscosity is lO~500
Preferably, it is 0 centivoise (measured at 25° C. at 60 revolutions per minute using a Brookfield viscometer).

The present invention also provides a method for sizing paper, which comprises sizing paper or paperboard using the papermaking sizing agent composition.

Next, the present invention will be explained in detail.

The ketene dimer compound used in the present invention is a compound represented by the above general formula (1>), and any of various known ketene dimer compounds can be used.

In the above general formula (1), R1 and R2 represent the same or different hydrocarbon groups having 8 to 30 carbon atoms, and examples of this hydrocarbon group include decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, etc. an alkyl group,
Examples include alkenyl groups such as tetradecenyl, hexadecenyl, and octadecenyl, alkyl-substituted phenyl groups such as octylphenyl and nonylphenyl, alkyl-substituted cycloalkyl groups such as nonylcyclohexyl, and aralkyl groups such as phenylethyl. preferable. These ketene dimer compounds may be used alone or in combination of two or more.

In addition, the polymer (b) of the present invention is a polymer obtained by polymerizing a hexamer containing 5 mol% or more of the monomer represented by the general formula (II) above, and a polymer having the general formula (I [)]. It may be a homopolymer containing 100 mol% of the heptamers shown, and the present invention also includes this.

As a heptamer copolymerizable with the heptamer represented by the above general formula (II), for example, as a cationic monomer,
(7-no, or di-alkyl)aminoalkyl (meth)
Acrylamides (e.g. dimethylaminopropyl methacrylamide, dimethylaminopropylacrylamide, etc.), (7- or di-alkyl)aminoalkyl (meth)acrylates (e.g. dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, etc.), (
Seven- or di-alkyl) aminohydroxyalkyl (meth)acrylate, vinylpyridine, vinylimidazole, diallylamine, etc. can be used, and further, quaternary ammonium salts thereof can be used. In addition, as nonionic heptamers, (meth)acrylamide, N, N-
Dimethylacrylamide, hydroxyethyl (meth)acrylate, etc. can be used. Furthermore, as anionic finishing agents, monomers having carboxylic acid groups such as (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and crotonic acid, vinyl sulfonic acid, (meth)
Monomers having a phosphate ester group such as heptamer 1 having a sulfonic acid group such as allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and sulfonated styrene, or a phosphate ester of hydroxyalkyl (meth)acrylate; These salts can be used,
As the hydrophobic monomer, styrene or its derivatives, alkyl (meth)acrylates, (meth)acrylonitrile, vinyl esters such as vinyl acetate or vinyl propionate, or methyl vinyl ether can be used.

Although these monomers can be used in appropriate combinations, (meth)acrylamide is particularly preferred.

The polymer (bl) used in the present invention is a polymer obtained by polymerizing a heptamer represented by the general formula (II) above, containing 5 mol% or more, preferably 20 mol% or more. If this amount is less than 5 mol%, even if this polymer is used together with the above components (al, etc.) within the range of the present invention, the size effect will be insufficient immediately after the paper or paperboard is dried. It is.

Conventionally known methods can be used to synthesize the polymer of (bl) above. That is, the monomer represented by general formula (II), or the monomer represented by general formula (II) and other monomers, is mixed with water; methanol. , alcohols such as ethanol, isopropyl alcohol; dimethyl sulfoxide, dimethyl formamide, etc.; a mixture thereof; etc., in the presence of a radical polymerization catalyst. Persulfates such as ammonium sulfate, potassium persulfate, and sodium persulfate, redox polymerization catalysts using a combination of these persulfates and a reducing agent, or 2,2゛-azobis-(2-amidinopropane) dihydrochloride, 2.2 Examples include ab-based catalysts such as '-azobisisobutyronitrile. Also, known chain transfer agents can be used as appropriate, if necessary.

The viscosity of the above (bl) polymer solution obtained in this way is 10 to 5000 centipoise as a 20% aqueous solution (however, the viscosity is
(value measured at 5° C.) can be used, and those having a viscosity of 50 to 1000 centipoise are particularly preferred. When this viscosity is lower than 10 centivoise or higher than 5,000 centivoise, when it is used as the component ('b) of the present invention, the emulsifying property and storage stability are lower than those using a viscosity within the above viscosity range. , tends to be inferior.

The above polymer ('b) is 2.5 to 2.5 parts by weight based on 100 parts by weight of the ketene dimer compound represented by the above general formula (1).
It is recommended to use 100 parts by weight, preferably 5 to 50 parts by weight. If it is less than 2.5 parts by weight, the emulsifying property will be poor and a stable paper sizing agent composition cannot be obtained;
If the amount exceeds parts by weight, it will not only be economically disadvantageous;
Negative impact on size effect.

In the present invention, as described above, (a compound of (al), (
By using the bl polymer in combination, the papermaking sizing composition can have excellent storage stability and excellent sizing effects immediately after paper making and drying, but if necessary, cationized starch and/or sulfonic acid groups, It is also preferable to use an anionic dispersant containing one or more selected from the group consisting of esters and salts thereof, since the storage stability of the sizing agent can be further improved.

As this cationized starch, corn, potato or tapioca starch containing primary, secondary, 37th mino groups or quaternary ammonium salts can be used, and the general formula (
It is preferable to use 0 to 50 parts by weight, preferably 3 to 30 parts by weight, per 100 parts by weight of the ketene dimer compound represented by 1).

As the anionic dispersant, for example, genin sulfonate, naphthalene sulfonate-formaldehyde condensate, etc. can be used, and ketene dimer type compound 10
15 parts by weight or less, preferably 0.1 to 0 parts by weight
5 parts by weight are used.

In the present invention, substances conventionally used in ketene dimer-based sizing agents, such as nonionic dispersants such as sorbitan esters, can also be used in combination.

The paper sizing agent composition of the present invention can be produced by a conventionally known method. For example, a ketene dimer compound represented by formula (1) above is combined with the polymer (in the above) and, if necessary, a cationized starch and/or an anionic dispersant. It is obtained by mixing it in an aqueous solvent and uniformly dispersing it with various known emulsifiers such as a homomixer, a high-pressure discharge type homogenizer, and an ultrasonic emulsifier. The order of mixing may be, for example, mixing the ketene dimer compound, the above-mentioned polymer (bl), and an anionic dispersant if necessary in an aqueous medium, uniformly dispersing the mixture, and then mixing the cationized starch. The ketene dimer compound and cationized starch may be mixed in an aqueous medium with an anionic dispersant if necessary, and after uniformly dispersing the mixture, the polymer of (bl) may be mixed.

The paper sizing agent composition of the present invention thus obtained has a dispersed phase particle size of 10μ or less, a solid content concentration of 15 to 30% by weight, extremely excellent storage stability, and Alternatively, an excellent size effect can be exhibited immediately after the paperboard is made and dried.

The paper sizing agent composition of the present invention can be used by conventionally known methods. For example, in the manufacturing process of paper or paperboard, it is possible to use either a so-called internal sizing method in which the material is added to the wear/end portion, or a so-called surface sizing method in which it is applied or impregnated after the formation of the A-layer.

When used in the internal addition sizing method, the papermaking sizing agent composition of the present invention is added to an aqueous pulp dispersion at a solid content of 0.002 to 3% by weight, preferably 0.002 to 3% by weight based on the dry weight of the pulp.
．． 005 to 2% by weight of solids is added.

Pulp raw materials include bleached or unbleached chemical pulps such as kraft valve or sulfide pulp, bleached or unbleached high-yield pulps such as ground wood pulp, pulp valves or thermomechanical pulp, used newspapers, used magazines, used corrugated paper, or decomposed pulp. Any waste paper pulp, such as ink waste paper, can be used.

Additives such as fillers, dyes, dry paper strength improvers, wet paper strength improvers, and retention improvers may also be used as necessary, and size presses, gate roll coaters, bill blade coaters, gear renders, etc. If necessary, starch, polyvinyl alcohol, dye, coating color, surface sizing agent, anti-slip agent, etc. may be applied.

The internal addition sizing method using the papermaking sizing agent composition of the present invention exhibits a sizing effect immediately after paper or paperboard is dried, reduces staining of papermaking equipment, and improves operability. can.

When the paper sizing agent composition of the present invention is used in a surface sizing method, the M paper size of the present invention may be added to the surface coating liquid applied by a size press, gate roll coater, bill blade coater, gear render, etc. The agent composition may be added to the paper surface in an amount of 0.005 to 0.5 g/m (dry weight).

EXAMPLES The present invention will be described in detail below in Examples, but the present invention is not limited thereto. In the Examples and Comparative Examples below, % and parts mean % by weight and parts by weight, respectively, unless otherwise specified.

Example 1 330 g of a 60% aqueous solution of the monomer having the general formula % 10l-, 4 g of isopropyl alcohol, and ions were placed in 11 four-eye flasks equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube. 165 g of exchanged water was charged, and the pH was adjusted to 3.8 with a 20% sulfuric acid aqueous solution. Nitrogen gas was introduced into this mixed solution while stirring, and after removing oxygen, the temperature was raised to 65° C., and 1.4 g of a 5% aqueous solution of ammonium persulfate was added to initiate polymerization. After that, the temperature was raised to 80°C and held at 80°C for 1.5 hours, and then 0.7g of a 5% aqueous solution of ammonium persulfate was added, and an additional 1.5
The polymerization was completed by maintaining the same temperature for a period of time. 490 g of ion-exchanged water was added to the obtained polymerization product to reduce the non-volatile content to 20
．． Brookfield viscosity (hereinafter referred to as viscosity) of 930 centipoise (hereinafter referred to as viscosity) measured at 5%, 25°C, and 60 revolutions per minute.
(hereinafter referred to as cps), a polymer aqueous solution pt having a pH of 4.2 was obtained.

Next, 18.18 parts of a ketene dimer compound (made from a mixture of 40% palmitic acid chloride and 60% stearic acid chloride), 8.137 parts of the polymer aqueous solution P-1 obtained by the above polymerization, and ion exchange were added. After heating 72.95 parts of water to 70°C and pre-dispersing it in a homomixer, the mixture was heated to 72.95 parts by a high-pressure discharge type homogenizer under a shear pressure of 250 kg/csl while maintaining the same temperature.
The mixture was passed through for uniform dispersion. After cooling, the aqueous dispersion was filtered through a 325-mesh wire mesh to obtain paper sizing agent composition E-
I got 1. This papermaking sizing agent composition E-1 had a nonvolatile content of 20.2%, a viscosity of 43.0 cps, and a pH of 3.5. In order to examine the storage stability of paper sizing agent E-1, it was stored at 32° C. for one month and changes in viscosity over time were examined.

The results are shown in Table 2.

Examples 2 to 5 Example 1 except that the seven-layer composition was changed to that shown in Table 1.
Polymerize in the same manner as above to obtain polymer aqueous solutions P-2 to P-5.
I got it. Note that the amount of isopropyl alcohol for viscosity adjustment was changed as appropriate each time. Next, a paper sizing agent composition E was prepared in the same manner as in Example 1, except that the blending ratio of ketene dimer compound/the above (bl polymer/cationized starch/anionic dispersant) was changed as shown in Table 2. -2～
E-5 was obtained, and the storage stability was investigated in the same manner as in Example 1, and the results are shown in Table 2. In addition, in Table 1, the symbols indicate the following.

G1; In the general formula (IT), n=3, R3=
H1R4=CH3, R5=CH3, R, CI+3, R
fC) I3, R5=CH3, X-ECI! S y =
Monomer 2 with czs; Quaternized product M-3 of dimethylaminopropylacrylamide with methyl chloride; Quaternized product M-4 of dimethylaminoethyl methacrylate with methyl chloride; Acrylamide Comparative Examples 1-3 Same as Examples 2-5 Polymer aqueous solution n shown in Table 1
pt~RP-3 were obtained, and paper sizing agent compositions RE-1~I? were obtained in the same manner using the same. Table 2 shows the results of obtaining E-3 and examining its storage stability in the same manner.

Example 6 17.32 parts of the ketene dimer compound used in Example 1, 3.15% cationized starch aqueous solution (quaternary ammonium salt containing 0.4% nitrogen atoms) gelatinized at 90°C for 1 hour
(containing cationized potato starch) 82.46 parts and 40
% of an aqueous solution of sodium naphthalene sulfonate-formaldehyde condensate was heated to 70°C, predispersed in a homomixer, and then transferred to a high-pressure discharge type homogenizer under a shear pressure of 250 kg/cXI+ while maintaining the same temperature. It was passed twice to ensure uniform dispersion. After cooling 88.5 parts of this aqueous dispersion, it was mixed with 11.5 parts of polymer aqueous solution P-6 shown in Table 1, and filtered through a 325 mesh wire gauze to prepare the aqueous dispersion paper sizing composition E- I got 6. This was also measured in the same manner as above, and the results are shown in Table 2.

Comparative Examples 4 to 6 Three types of commercially available papermaking sizing agent compositions 1'1E-4 to RE-6 containing ketene dimer compounds were used as comparative examples.
Table 2 shows the results of examining their physical properties and storage stability.

(Margins below this page) Table 1 (Monomer composition and composition of bl polymer aqueous solution (margins below this page) Table 2 (Composition, physical properties and storage stability of paper sizing agent compositions) In Table 2, ketene dimer The compound was made from a mixture of 40% valmitic acid chloride and 60% stearic acid chloride, the polymer aqueous solution was as listed in Table 1, and the cationized starch was cationized potato starch that was a quaternary ammonium salt and contained 0.44% of nitrogen atoms. The anionic dispersant was a sodium naphthalene sulfonate-formaldehyde condensate; however, in Example 2, sodium geninsulfonate was used, and the storage stability was This is the viscosity after storage at 32°C for one month.

Next, a size effect test was conducted using the paper sizing agent composition obtained above.

That is, pulp slurry (BKPL/
20% of heavy calcium carbonate (Niscallon 1500, manufactured by Sankyo Seifun Co., Ltd.) was added to 380 ml of Canadian Standard Freeness (N = 8/2), and after stirring for 2 minutes, cationized starch (Cate F, egg (manufactured by National Corporation) 0.75% and pan sulfate ±0.5% were sequentially added, and the mixture was further stirred for 2 minutes. Then, the pulp slurry concentration was set to 0.2
After diluting to 4%, paper sizing agent compositions E-1 to E-6 and RE- obtained in Examples 1 to 6 and Comparative Examples 1 to 6
0.12% each of 1 to RE-6, retention improver (Hiletin 104, manufactured by Dick Vercules) 0.
02% was added and stirred for 1 minute. Using the paper stock thus obtained, wet paper paper having a basis weight of 70 g/rrr was obtained using a hand paper making machine manufactured by Nople & Wood. In addition,
Papermaking pH was 8.0. This wet paper has a moisture content of 59.0
%, then press at 80° with a drum dryer.
It was dried for 370 seconds. Immediately after drying, paper with a moisture content of 4.0% was obtained. This paper immediately after drying, 20℃, relative humidity 65%
The Steckigt sizing degree of the paper after 7 days in the atmosphere was measured according to JIS P-8122. The results are shown in Table 3.

In addition, the addition rate of the filler and chemicals mentioned above is the solid content weight % with respect to the dry pulp weight.

(Margins below this page) Table 3 (Size effect test results of paper sizing compositions) Examples 7 to 12 and Comparative Examples 7 to 10 Also, when paper making was performed continuously, A test was conducted to see how the lees contaminated the equipment.

That is, among the paper stock used in the size effect test, the same paper stock as the corresponding paper stock used in Examples 1 to 6 and Comparative Example 1.4.5.6 was prepared, and this paper stock was was made using a pilot machine. Each stock was allowed to run for 15 minutes and was continuously changed to the next stock. It took 10 minutes for the papermaking system to stabilize after switching, so the lees that had accumulated on the doctor of No. 2 press were collected and dried between 10 minutes after switching and 5 minutes before switching to the next paper stock. and weighed. The results are shown in Table 4.

(Margins below this page) Note that the paper-making conditions are as follows.

Paper machine: Fourdrinier/multi-tube biloft machine Paper speed: 2
5m/min Papermaking pH: 7.9 Papermaking temperature: 18°C Basis weight: 65g/m Above, based on Table 2.3, the papermaking sizing agent compositions of Examples 1 to 6 and Comparative Examples 1 to 6 were When compared, the examples have good storage stability, and when comparing the size effects using these paper sizing agent compositions, the examples have good size effects immediately after drying, and after aging. It can be seen that the size effect is also excellent. Furthermore, when comparing the papermaking methods of Examples 7 to 12 and Comparative Examples 7 to 10, the amount of lees from the papermaking sizing agent compositions contaminating the equipment was significantly lower in both methods than in Examples 7 to 10. It can be seen that this is due to the use of paper sizing agent compositions Nos. 1 to 7.

Effects of the Invention According to the present invention, a ketene dimer compound is used in combination with the above-mentioned polymer, and if necessary, a cationized starch and/or an anionic dispersant are used in combination, so paper making using these as main components is possible. It is possible to improve the storage stability of the sizing agent composition for paper manufacturing, improve the sizing effect of paper immediately after paper making and drying using this sizing agent composition for paper manufacturing, and improve the sizing effect of paper using this sizing agent composition for paper manufacturing. By making paper using the same method, it is possible to reduce the amount of dirt on the equipment due to the residue of the papermaking sizing agent composition, and it is possible to improve the operability.

March 30, 1985

Claims (5)

[Claims] (1) (a) A ketene dimer compound represented by the general formula (I) below, and ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 and R_2 are the same or different carbon atoms of 8 to 3
0 hydrocarbon group. ) (b) A polymer obtained by polymerizing monomers containing 5 mol% or more of the monomer represented by the following general formula (II) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, n is 2, 3, or 4, R_3 represents a hydrogen atom or a methyl group, R_4 to R_8 are the same or different lower alkyl groups having 1 to 3 carbon atoms, and X^- and Y^- represent the same or different anions. A paper-making sizing agent composition comprising 2.5 to 100 parts by weight of the polymer (b) per 100 parts by weight of the compound (a). (2) The paper sizing composition according to claim 1, which contains 50 parts by weight or less of cationized starch per 100 parts by weight of the compound (a). (3) 15 parts by weight of an anionic dispersant containing one or more selected from the group consisting of sulfonic acid groups, sulfuric acid ester groups, and salts thereof based on 100 parts by weight of the compound (a) above. The paper sizing agent composition according to claim 1 or 2, characterized in that it contains the following: (4) The polymer of (b) above consists of a polymer of monomers consisting of 5 to 100 mol% of the monomer represented by the general formula (II) and 0 to 95 mol% of acrylamide and/or methacrylamide, and The viscosity of a 20% aqueous solution is 10 to 5000 centipoise (however, Brook
The paper sizing agent composition according to claim 1, 2, or 3, which has a value measured at 25° C. at 60 revolutions per minute using a field viscometer. (5) A method for sizing paper, which comprises sizing paper or paperboard using the papermaking sizing composition according to claim 1, 2, or 3.