JPH04153393A - Sizing for paper making and sizing agent composition - Google Patents

Abstract

PURPOSE:To carry out the title sizing having excellent sizing effects and improved releasability without reducing fluorescent strength by using both a polymer-based sizing agent and an alkylketene dimer-based sizing agent having specific molecular structure units. CONSTITUTION:Sizing is carried out using both a polymer-based sizing agent prepared by dispersing a polymer containing structural units shown by formula I to formula III [R1 is H or CH3; R2 is H, CH3, CH(CH3)2 or C(CH3)3; R3 is H or CH3; R4 is 1-22C alkyl, 3-22C alkenyl, cyclohexyl, phenyl, benzyl or glycidyl; R5 is 1-22C alkyl, 3-22C alkenyl or benzyl; R6 is H or methyl; A is O or -CH2NH; X<-> is anion] and a sizing agent containing a ketene dimer-based compound shown by the formula IV (R7 and R8 are 6-20C hydrocarbon).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a sizing agent composition that has excellent size effects, good disintegration properties of waste paper, and has little effect on fluorescent dyes, and a sizing method for paper manufacturing using the same. Regarding.

[Conventional technology]

Conventionally, in paper manufacturing methods for ordinary paper and paperboard, sizing has been performed to impart functions such as sizeability, waterproofness, and water resistance to these papers. As this sizing method, a sizing agent is added to the paper stock before the paper layer is formed, or a sizing agent is applied after the paper layer is formed, in the paper or paperboard manufacturing process.

In recent years, neutral sizing agents have been used to improve the pH value of pH 6.
, 5 to 9, the so-called neutral sizing method is attracting attention.

Examples of neutral sizing agents include reactive sizing agents, such as alkyl ketene dimer sizing agents and alkenylsuccinic anhydride sizing agents, which exhibit sizing properties by reacting with the hydroxyl groups of cellulose in the paper stock. For example, styrene-dimethylaminoethyl (
Examples include self-fixing sizing agents typified by meth)acrylate-epihalohydrin resin sizing agents (hereinafter abbreviated as SDE). Currently, among these neutral sizing agents, alkyl ketene dimer sizing agents are most commonly used.

[Problem to be solved by the invention]

However, when using an alkyl ketene dimer-based sizing agent, although it has the advantage of providing excellent sizing effects, it not only takes time for the sizing effect to appear, that is, the rise in sizing is slow; When the addition rate is increased, there are problems such as the paper becoming slippery and problems such as adhesion to the press rolls and smoother rolls of the paper machine during paper making and staining them.

In addition, when SDE is used alone, alkyl ketene dimer-based sizing agents do not have any good sizing effect, and even if the addition rate is increased, it is difficult to improve the sizing degree.
It is not appropriate to use it alone. Not only that, SD
Since R is a cationized resin with shrimp herrohydrin, there are problems with poor disintegrating properties, which loosen the fibers of waste paper when it is collected, and a fluorescent dye is added that has the effect of improving the whiteness of the paper. In this case, the problem arises that the cationic nature of the resin is too strong, reducing the fluorescence intensity of the fluorescent dye.

Therefore, a sizing method using a combination of an alkyl ketene dimer sizing agent and SDR is also known (Japanese Unexamined Patent Publication No. 1983-1989-1).
132789, JP-A-57-112497). By using these sizing agents in combination, the rise in sizing is improved, and by reducing the amount of the alkyl ketene dimer sizing agent, problems such as press roll staining and paper slippage can be improved.

However, even when these sizing agents are used in combination, the rise in sizing is still slow and the sizing is still insufficient. Furthermore, the problems of poor disintegration of waste paper and reduction of fluorescence intensity of fluorescent dyes due to the use of SDR still remain, and a satisfactory sizing agent has not been obtained even when these sizing agents are used in combination.

The object of the present invention is to provide a sizing agent composition that has good sizing, excellent sizing effect, good disintegration of waste paper, and does not easily reduce the fluorescence intensity of fluorescent dye, and a sizing method for paper manufacturing using the same. It is about providing.

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the present inventors found that the above object could be achieved by using a polymeric polymer-based sizing agent and an alkyl ketendamer-based sizing agent in combination, and completed the present invention. This is what led me to do this.

That is, the present invention provides at least the following general formula (1), (
A size containing a polymerized polymer sizing agent containing a polymer having molecular structural units represented by II) and (In) dispersed in water, and a ketene dimer-based compound represented by the following general formula (IV). The purpose of the present invention is to provide a sizing method for paper manufacturing in which sizing is performed in combination with an agent.

(In the formula, R1 is H or CH3, R2 is H or CH3, -
C) Represents a lower alkyl group such as I(CH3)2, -C(CH3)3. ) General formula (n) (wherein R3 is H or CH3, R4 is an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 3 to 22 carbon atoms, a cyclohexyl group, a phenyl group, a benzyl group, a glycidyl group ) General formula (III) (wherein, R5 is an alkyl group having 1 to 22 carbon atoms, 3 carbon atoms
-22 alkenyl group or benzyl group, R6 is hydrogen or methyl group, A is oxygen atom or -C)12NHX-
indicates an anion. ) General formula (IV) (In the formula, R7 and R8 represent the same or different hydrocarbon groups having 6 to 30 carbon atoms.) In this case, the above polymer has the above general formula (1), (n) and ( In addition to the molecular structural unit represented by H[), the following general formula (
It is also preferable to have a molecular structural unit represented by V).

General formula (V) (In the formula, R9 represents H or CHf.) In the above paper manufacturing sizing method, a sizing agent containing a mixture of a polymeric polymer sizing agent and an alkyl ketene dimer sizing agent may be used. preferable.

The present invention also provides a sizing agent composition for use in the above-mentioned paper manufacturing sizing method.

Next, the present invention will be explained in detail.

In the present invention, the combined use of a polymeric polymer-based sizing agent and an alkyl ketene dimer-based sizing agent includes both a case in which they are used separately and a sizing agent containing a mixture thereof.

The polymerized polymer sizing agent has at least the above general formula (1
), (U), CI[l] is contained in water, and this polymer contains these molecular structural units L (only the corresponding monomers, or they can be combined with other monomers (
It can be obtained by polymerizing it together with a vinyl monomer such as meth)acrylamide.

Monomers corresponding to the above general formula (I) include styrene, vinyltoluene, α-methylstyrene, etc., and monomers corresponding to the above general formula (II) include methyl (meth)acrylate, butyl (meth)acrylate, etc. Acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc., and the above general formula (III)
Examples of monomers corresponding to N-ethyl-N,N-dimethyl(2(meth)acryloyloxyethyl)ammonium bromide,
-(meth)acryloyloxyethyl)ammonium chloride, N-ethyl-N,N-dimethyl(3-(meth)acryloylaminopropyl)ammonium bromide, N-benzyl-N,N-dimethyl(3-(meth)acryloylamino (propyl) ammonium chloride and the like.

One or more of the above monomers may be used.

The method for preparing the monomer represented by the general formula (III) above is not particularly limited, but generally speaking, the method for preparing the monomer represented by the general formula (III) shown below is
■°) The tertiary monomer represented by
A method of quaternization using benzyl halide or the like may be considered.

(In the formula, R6 is H or CH, A is an oxygen atom or -CH
Indicates 2NH. ) The above polymer can also be obtained by a method of preparing a hexamer of general formula (I[I) by quaternization and then polymerizing it with monomers of general formula (1), (IT), etc.; ■′)
The monomer may be quaternized with a quaternizing agent during or after polymerization with the monomer of general formula (I), (II), etc.

Monomers that satisfy the above general formula (■゛) include N, N
-dimethylaminoethyl (meth)acrylate or N,
Examples include N-dimethylaminopropyl (meth)acrylamide, which may be used alone or in combination of two or more.

As the constituent molar ratio of the hepatomer corresponding to the molecular structural unit of the general formula (1), the heptamer of the general formula (1) is 50 to 95%,
Preferably it is 60 to 90%; if it is less than 50%, the size effect will be low, and if it is more than 95%, the resulting polymer may have poor dispersibility in water. The molar ratio of the monomer of general formula (n) is 0.5 to 40%, preferably 1 to 30%.
%, and if it is less than 0.5% or more than 40%, the size effect may decrease. The monomer of general formula (III) is present in an amount of 2 to 40%, preferably 5 to 30%; if it is less than 2%, the water dispersibility of the obtained polymer may decrease, and if it is more than 30%, The size may be reduced, which is disadvantageous in terms of cost.

In the present invention, in addition to the monomers of the above general formulas (1), (II) and (I[I), other monomers can also be used, such as monomers corresponding to the above general formulas (■,), ) When acrylamide is used as a polymerization component, a decrease in the fluorescence intensity of the fluorescent dye can be suppressed. In addition, the viscosity of the obtained aqueous polymer dispersion becomes low, making it possible to increase the concentration of the product. In this case, the combined molar ratio of (meth)acrylamide is 0.5 in the total monomers used.
-30%, preferably 1-20%.

Other monomers listed above include (meth)acrylonitrile, olefin, vinyl ether, allyl ester,
vinyl ketone, vinyl sulfonamide, N-vinyl-2
-pyrrolidone, 2-hydroxyethyl (meth)acrylate, diacetone acrylamide, N-alkyl (meth)acrylamide, divinylbenzene, methylenebisacrylamide, (meth)acrylic acid, maleic acid, fumaric acid, cinnamic acid, itaconic acid , allylamine, diallylamine, vinylpyridine, and N-ethyl-4-vinylpyridinium ethosulfate, and these monomers can be used alone or in an amount of 2M or more.

As a method for polymerizing the polymer used in the present invention, the above monomers are subjected to a polymerization reaction using solution polymerization or bulk polymerization in the presence of a radical polymerization initiator.

A polymerized polymer sizing agent is prepared by dispersing the obtained polymer directly or together with an additive such as a dispersant in water, distilling off the solvent as necessary, and adjusting the solid content to a predetermined concentration.

The alkyl ketene dimer sizing agent used in the present invention is an aqueous dispersion containing an alkyl ketene dimer represented by the following general formula (TV).

(In the formula, R7 and R8 represent hydrocarbon groups such as the same or different alkyl groups or alkenyl groups having 6 to 30 carbon atoms.) These alkyl ketene dimers can be used singly or in a mixture of two or more. .

A method for producing an alkyl ketene dimer-based sizing agent is, for example, by adding the alkyl ketene dimer represented by the general formula (rV) to an aqueous solution together with a protective colloid, a dispersant, or both at a temperature higher than the melting point of the alkyl ketene dimer. It can be obtained by mixing and uniformly dispersing the mixture using various emulsifiers such as a homomixer, a high-pressure discharge type homogenizer, and an ultrasonic emulsifier.

Examples of protective colloids and dispersants include cationic starch, cationic dispersants such as polydiallyldimethylammonium halide, anionic dispersants such as naphthalene sulfonic acid-formaldehyde condensates, and lignin sulfonates, and nonionic dispersants such as sorbitan esters. Examples include dispersants and polymeric protective colloids such as cationic, anionic, and amphoteric acrylamide polymers. These are 1
A species or two or more species may be used in combination.

The amount of the polymer sizing agent used in the present invention added to the paper stock is 0.01 to 2%, preferably 0.03 to 1%, based on the dry pulp, and the amount of the alkyl ketene dimer sizing agent added is: 0.01-2% based on dry pulp
, preferably 0.03 to 1%. If the addition rate of these sizing agents is less than 0.01%, the sizing effect will not be sufficient, and if it is more than 2%, the cost will increase.

The ratio of the polymer sizing agent and the alkyl ketene dimer sizing agent used in combination is 1/99 to 99/1, preferably 5/95 to 9515.

The location where the polymer sizing agent and alkyl ketene dimer sizing agent used in the present invention are added in the papermaking process is not limited, but is preferably between the seed box and the front of the screen, and in the pulp slurry. It is desirable that the sizing agent be well dispersed. There are no restrictions on the order of addition; the polymeric polymer sizing agent is added first;
Then, the alkyl ketene dimer sizing agent may be added in this order, or vice versa, these may be added at the same time, or a mixture of these may be added.

This liquid mixture serves as a sizing agent as it is, but a dispersant and other additives may be added thereto. In this case, the mixing ratio of the above polymer and alkyl ketene dimer is 1/99 to
99/1, preferably 5/95 to 9515.

The above-mentioned sizing agents can be used in the production of paper or paperboard, specifically for neutral printing writing paper, neutral coated base paper, neutral pp
It can be used in the production of c-paper, neutral pure white, neutral liner, canning liner, etc.

In producing the various papers or paperboards mentioned above, pulp raw materials include bleached or unbleached chemical pulp such as kraft pulp or sulfide pulp, ground wood pulp,
Any bleached or unbleached high-yield pulp such as mechanical pulp or thermomechanical pulp, or waste paper pulp such as old newspaper, old magazine, old cardboard, or deinked old paper can be used. Further, mixtures of the above-mentioned pulp raw materials and asbestos, polyamide, polyester, polyolefin, etc. can also be used.

In addition, fillers, dyes, dry paper strength enhancers, yield silver improvers,
Additives such as freeness improvers may also be used as necessary in order to exhibit the physical properties required for each paper type. Examples of the filler include clay, tarlsium, etc., and these may be used alone or in combination.

Examples of retention improvers include sulfuric acid clay, anionic or cationic high molecular weight polyacrylamide, a combination of silica gel and cationized starch, and a combination of bentonite and anionic or cationic high molecular weight polyacrylamide.

Examples of the filtration agent include polyethyleneimine, cationic polyacrylamide, and the like. In addition, starch, polyvinyl alcohol, dyes,
Coating color, surface sizing agent, anti-slip agent, etc. may be applied as necessary.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. In the following Examples and Comparative Examples, % means solid content weight % unless otherwise specified.

Production Example 1 of Polymer Sizing Agent 72.9 g of styrene, 9.2 g of 2-ethylhexyl acrylate, N-ethyl-N,N dimethyl were placed in a 1-lindle four-bottle flask equipped with a stirrer, a thermometer, and a cooling tube. 53.2 g of -(2-methacryloyloxyethyl) ammonium bromide, 7.1 g of 50% aqueous acrylamide solution, 141 g of isopropyl alcohol, and 2 g of azoisobutylnitrile were added, and the mixture was reacted at 80° C. for 5 hours in a nitrogen stream. Next, add 412 g of water, stir well to disperse it in water, cool it, and add 700 g of water to the polymeric soothing agent.
I got g. Its solids content was 20%.

Production Example 2 of Polymerized Polymer Sizing Agent B Polymerized polymer sizing agent B was prepared in the same manner as in Example 1 except that the monomer composition was changed to the monomer composition shown in Table 1.
-F was produced.

In the table, Me: methyl group, EL: ethyl group, Bz: benzyl group, St: styrene, former acrylamide, El (A: 2-ethylhexyl acrylate,
EIIM: 2-ethylhexyl methacrylate, Bl butyl acrylate, Epi: shrimp chlorohydrin, A
C-: Acetate ion. % represents mol%.

Comparative Production Examples 1 to 2 of Polymer Sizing Agents Polymer polymer sizing agents G1H were produced in the same manner as in Example 1, except that the monomer compositions shown in Table 1 were used.

Comparative production example 3 of polymerized polymer sizing agent In a 1-liter four-loaf flask equipped with a stirrer, thermometer, and cooling tube,
Styrene 83.3g, N,N-dimethylaminoethyl methacrylate (under J22, abbreviated as DM) 31.4g1
118 g of benzene and 2 g of azoisobutylnitrile were added, and the mixture was reacted at 80° C. for 5 hours in a nitrogen stream. Next, 425 g of acetic acid solution was added and heated to 97°C, and benzene was distilled off. After distillation, the distilled amount of water was replenished, 18.5 g of epichlorohydrin was added, and the reaction mixture was reacted at 80° C. for 3 hours and then cooled to obtain 670 g of polymer sizing agent I. Its solids content was 20%. The styrene/[1M molar ratio of the polymer sizing agent (1) was 80/20, which means that the styrene/[1M] molar ratio was graded with epichlorohydrin after polymerization.

Table 1 (Margins below this page) Example 1 2.5% pulp slurry (tlKP L/N=8/2
, Canadian Standard Freeness 390
0.01% of fluorescent dye (MIKEPHORBX, manufactured by Mitsui Toatsu Chemical Co., Ltd.) and 10% of light calcium carbonate (Tamavar 121, manufactured by Okutama Kogyo Co., Ltd.) were added to m7ri, and after stirring for 2 minutes, cationized starch (Kate) was added. 0.6% of F. manufactured by Oji National Co., Ltd.) was added, and the mixture was further stirred for 2 minutes. Next, the pulp slurry was diluted to 0.25% and treated with an alkyl ketene dimer sizing agent (Burcon 701).
, manufactured by Dick Vercules Co., Ltd.) and 0.2% of polymeric polymer sizing agent A, and then 0.02% of a yield improvement agent (Hiretin 104, manufactured by Dick Vercules Co., Ltd.). After adding it and stirring for 1 minute, it was made into a sheet with a basis weight of 70 using a hand paper machine manufactured by Nople & Wood.
A wet paper of g/m was obtained. At this time, the paper making pi (pi) was 8.0. This wet paper was pressed and then dried for 180 seconds at 80° C. using a drum dryer.

The obtained handmade paper was heated immediately after papermaking and at 65% humidity and 20°C.
After controlling the humidity in a constant temperature room for 24 hours, JIS P-8122
The Steckigt size degree was measured according to JISP-81.
The wet tear length was measured according to No. 35. Regarding the fluorescence intensity, the fluorescence intensity at 443 nm was measured using a spectrofluorometer FR-770 (manufactured by JASCO Corporation). The higher the measured value, the stronger the fluorescence intensity.

Furthermore, a disaggregation test was conducted in the following manner. First, 5 g of each handmade paper was cut into 1 cm square pieces, soaked in 1 liter of water, and stirred at 280 rpm for 10 minutes to observe the degree of loosening of the paper pieces. ○ indicates that the paper pieces have completely loosened into fibers, and × indicates that the paper pieces still remain without peeling off. Generally, the higher the wet strength, the worse the disintegration property tends to be. The results of these measurements are shown in Table 2.

Examples 2 to 6 In Example 1, the polymer size? Paper was made in the same manner as in Example 1 except that B-F was used instead of IA, and the results are shown in Table 2.

Comparative Examples 1 to 3 Paper was made in the same manner as in Example 1, except that G to ■ were used in place of the polymerized soothing agent. Table 2 shows the results of measurements performed in the same manner as in Example 1.

Comparative Example 4 Paper was made in the same manner as in Example 1 except that the polymeric chair ax 18 was not used, and the results were measured in the same manner as in Example 1. Table 2 shows the results.

(Ni-no-Ashibe T-Company table (Ni-no ¥4. Shijin Shimomutai) From the above results, Examples 1 to 6 showed better size effects than Comparative Example 3, and immediately after production and after 1 day. It can be seen that the sizing rate is almost the same, the rise in sizing rate is good, the disintegration of the waste paper is good, and there is little effect on the fluorescence intensity of the fluorescent dye. This is the effect of using an alkyl ketene dimer-based sizing agent in combination.In particular, the improvement in disintegration property is remarkable, and this is the effect of the polymerized polymer-based sizing agent.In addition, Examples 1 to
Comparative Example 6 has a better size effect than Comparative Example 2.3, but this is due to the effect of introducing the molecular structural unit of general formula (U), and the polymer with (meth)acrylamide introduced also has a lower fluorescence intensity of the fluorescent dye. It can be seen that it is difficult to reduce the

〔Effect of the invention〕

According to the present invention, since the polymerized polymer sizing agent having the intervening structural unit of the above general formula and the alkyl ketene dimer sizing agent are used together, the sizing effect is excellent, the disintegration property is good, and the fluorescence of the fluorescent dye is improved. It is possible to provide a sizing agent and a sizing method for paper manufacturing that do not reduce light intensity.

October 12, 1990

Claims (4)

[Claims] (1) At least the following general formulas (I), (II) and (II)
A polymer sizing agent containing a polymer having a molecular structural unit represented by I) dispersed in water is used in combination with a sizing agent containing a ketene dimer compound represented by the following general formula (IV). Sizing method for paper manufacturing. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 is H or CH_3, R_2 is H or CH
_3, -CH(CH_3)_2, -C(CH_3)_3
Indicates a lower alkyl group such as. ) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R_3 is H or CH_3, R_4 is a carbon number of 1 to
22 alkyl group or alkenyl group having 3 to 22 carbon atoms,
Indicates a cyclohexyl group, phenyl group, benzyl group, and glycidyl group. ) General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (III) (In the formula, R_5 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 3 to 22 carbon atoms, or a benzyl group, and R_6
is hydrogen or methyl group, A is oxygen atom or -CH_2NH
-, X^- represent an anion. ) General formula (IV) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (IV) (In the formula, R_7 and R_8 are the same or different carbon numbers 6 to 3
0 hydrocarbon group. ) (2) The sizing method for paper manufacturing according to claim 1, wherein the polymer is a polymer having a molecular structural unit represented by the following general formula (V). General formula (V) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(V) (In the formula, R_9 indicates H or CH_3.) (3) The sizing method for paper manufacturing according to any one of claims 1 to 2, wherein a sizing agent containing a mixture of a polymeric polymer-based sizing agent and an alkyl ketene dimer-based sizing agent is used. (4) The sizing composition used in claim 3, which contains a polymerized polymer sizing agent and an alkyl ketene dimer sizing agent.