JPH01280097A - Internal size composition for paper making and method for internal sizing - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a ketene dimer based compound and specific polymer in a specified proportion and excellent in storage stability, mechanical stability and sizing properties. CONSTITUTION:The objective composition containing (A) 100 pts.wt. ketene dimer based compound expressed by the formula (R1 and R2 are 8-30C hydrocarbon) and (B) 2-100 pts.wt. polymer obtained by (co)polymerizing a vinylic monomer [e.g., monoalkylamino(hydroxy)alkyl (meth)acrylate or (meth)acrylamide] in the presence of a 6-22C alkyl mercaptan (preferably n-octyl mercaptan or n-dodecyl mercaptan). Furthermore, the above-mentioned alkyl mercaptan is preferably present in an amount of 0.01-10mol% based on the vinylic monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an internally added sizing agent composition for paper manufacturing, an internally added indimer-based internal sizing agent composition for paper manufacturing, and an internally added 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. This sizing method includes the so-called internal sizing method, in which an internal sizing agent is added to the paper stock before the paper layer is formed in the paperboard manufacturing process, and the other is the so-called internal sizing method, in which a surface sizing agent is applied to the paper surface after the paper layer is formed. Alternatively, there is a so-called surface sizing method that involves impregnation.

The internal addition sizing method uses a rosin sizing agent having a carboxyl group and a sulfuric acid band at pH 4.5 to 6.
．． Acidic sizing has been carried out by internally adding sizing in the acidic range of 5. On the other hand, in recent years, neutral sizing agents have been used for the purpose of using cheap calcium carbonate as a filler, using waste or waste paper containing calcium carbonate, closing water for paper making, and imparting permanent shelf life to paper. pH6.5~
Internal addition sizing in the neutral to slightly alkaline range of 9.
So-called neutral sizing methods have been attracting attention.

Neutral sizing agents currently on the market include ketene dimer compounds, substituted cyclic dicarboxylic acid anhydrides, copolymers of cationic and hydrophobic heptamers, cationized petroleum resins, and cationized fatty acid amides. Among these, aqueous dispersions of ketene dimer compounds are often used from the viewpoint of size effect.

Problems to be Solved by the Invention Conventionally, 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 precipitates. Furthermore, there is a problem in that effects such as sizeability and waterproofness are also reduced. In particular, it is extremely difficult to obtain an aqueous dispersion with high concentration and excellent storage stability and mechanical stability.

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 internal sizing agent composition for paper manufacturing using this method is still insufficient in terms of mechanical stability, storage stability, and size effect.

The object of the present invention is to provide a ketene dimer-based internal sizing agent composition for paper manufacturing that is highly concentrated and can enhance storage stability, mechanical stability, and size effect, and the use thereof. The purpose of the present invention is to provide a method for internally adding sizing.

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have taken the following steps: As a result of repeated studies, (a) a ketene dimer compound represented by the following general formula (1), (wherein R1 and R2 represent the same or different hydrocarbon groups having 8 to 30 carbon atoms) ) Contains a polymer obtained by polymerizing or copolymerizing a vinyl monomer in the presence of an alkyl mercaptan having 6 to 22 carbon atoms, (mountain relative to the compound ioo x position of al)
The present invention provides an internal sizing agent composition for paper manufacturing, which is characterized by containing 2 to 100 parts by weight of a polymer, and an internal sizing method using the same. In this case, it is preferable that the alkyl mercaptan having 6 to 22 carbon atoms in the above-mentioned pile is present in an amount of 0.01 to 10 mol % based on the vinyl monomer, and the polymer made of the vinyl monomer is an acrylamide polymer, or Preferably, it is a copolymer of acrylamide and a cationic vinyl monomer, or a copolymer of acrylamide, a cationic vinyl monomer, and an anionic vinyl monomer.

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 general formula (I), R1 and R2 represent the same or different hydrocarbon groups having 8 to 30 carbon atoms, such as 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. Among these, alkyl groups are preferred. These ketene dimer compounds may be used alone or in combination of two or more.

In addition, the polymer of the present invention is obtained by polymerizing or copolymerizing a vinyl monomer in the presence of an alkyl mercaptan having 6 to 22 carbon atoms, and the alkyl group having 6 to 22 carbon atoms is The raw material for the alkyl group may be either natural or artificially produced by cranking low polymerized paraffins such as ethylene or propylene. Examples include normal octyl mercaptan, normal dodecyl mercaptan, tertiary dodecyl mercaptan, normal hexadecyl mercaptan, and normal octadecyl mercaptan, which may be used alone or in combination of two or more. Among these, normal octyl mercaptan and normal dodecyl mercaptan are preferred.

In (b) of the present invention, the alkyl mercaptan having 6 to 22 carbon atoms is preferably 0.01 to 10 mol%, most preferably 0.05 to 2 mol%, based on the vinyl monomer involved in polymerization or copolymerization. used. If the alkyl mercaptan content is less than 0.01 mol%, it may not be possible to obtain a stable internal sizing agent composition for paper manufacturing.
In addition, if it is used in an amount exceeding 10 mol%, the amount of alkyl mercaptan that is not introduced into the polymer during polymerization or copolymerization reaction will increase, which may contaminate the equipment used for the polymerization reaction and have a negative effect on storage stability and size effect. There is,
Furthermore, the cost of the internal sizing agent composition for paper manufacturing increases.

Examples of vinyl monomers that are raw materials for the polymer (b) of the present invention include cationic vinyl monomers such as (7- or di-alkyl) amino (hydroxy) alkyl (meth)acrylate, (7- or di-alkyl); Alkyl)aminoalkyl(meth)acrylamide, vinylpyridine, vinylimidazole, diallylamine, etc. can be used, and salts of these inorganic or organic acids, quaternary ammonium salts, etc. can also be used. In addition, (meth)acrylamide, N
, N-dimethylacrylamide, hydroxypropyl (meth)acrylate, etc. can be used. Furthermore, as anionic vinyl monomers, (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid,
Monomers having a carboxylic acid group such as crotonic acid, vinyl sulfonic acid, (meth)allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, heptamers having a sulfonic acid group such as sulfonated styrene, or hydroxyalkyl ( Monomers having a phosphate ester group such as phosphoric esters of meth)acrylates can be used, and as hydrophobic vinyl monomers, styrene or its derivatives, alkyl (meth)acrylates, (meth)acrylonitrile, vinyl acetate or vinyl propionate can be used. Vinyl esters such as, methyl vinyl ether, etc. can be used. These monomers can be used singly or in an appropriate combination of two or more.

Among polymers made of these monomers, an acrylamide homopolymer, a copolymer of acrylamide and a cationic vinyl monomer, or a copolymer of acrylamide and an anionic vinyl monomer are preferable for the internal sizing agent composition for paper manufacturing. Preferably, it is a copolymer of acrylamide, a cationic vinyl monomer, and an anionic vinyl monomer.

To synthesize the polymer (b), conventionally known methods can be used. For example, the vinyl monomer is synthesized with methanol,
It is obtained by polymerizing with a radical polymerization catalyst in a lower alcohol such as ethanol or isopropyl alcohol, or in a mixture of these lower alcohols and water, and distilling off the lower alcohol after the polymerization is completed. Examples of radical polymerization catalysts include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, redox polymerization catalysts based on combinations of these persulfates and reducing agents, or 2,2''-azobis-(2-amidinopropane). ) dihydrochloride, and azo catalysts such as 2,2°-azobisisobutyronitrile.Furthermore, if necessary, a known chain transfer agent may be appropriately used in combination.

The viscosity of the above (bl) polymer solution obtained in this way is 10 to 5000 centivoise in a 2 Offi mass % aqueous solution (however, the viscosity is 60 centivoise per minute using a Brookfield viscosity needle).
It is preferable that the viscosity is 50 to 1000 centipoise (measured at 25°C under rotation).
When it is higher than 000 centiboise, compared to this one,
tends to be inferior.

The polymer (bl) is 2 to 100 parts by weight based on 100 parts by weight of the ketene dimer compound represented by the general formula (1).
It is good to use 5 to 50 parts by weight, preferably 5 to 50 parts by weight.
If it is less than 2 parts by weight, the emulsifying property will be poor and the storage stability and mechanical stability of the internal sizing agent composition for paper manufacturing will be lost. adversely affect the effectiveness.

In the present invention, cationized starch, carbon number 6 to
Polymer protective colloids such as cationic, anionic or amphoteric acrylamide polymers obtained by polymerization in the absence of alkyl mercaptan No. 22, anionic dispersants such as lignin sulfonates, naphthalene sulfonate-formaldehyde condensates, etc. Alternatively, nonionic dispersants such as sorbitan esters can also be used to the extent that they do not impede the stability of the internal sizing agent composition for paper manufacturing.

The paper-making internal sizing agent composition of the present invention can be produced by a conventionally known method. For example, the general formula (1)
The ketene dimer compound, the polymer (b), and, if necessary, the protective colloid or dispersant are mixed in an aqueous solvent at a temperature higher than the melting point of the ketene dimer compound represented by It can be obtained by uniformly dispersing it with various known emulsifiers such as a discharge type homogenizer and an ultrasonic emulsifier.

The thus obtained internal sizing agent composition for paper manufacturing of the present invention can exhibit its effects when the particle size of the dispersed phase is 10 μm or less.

The excellent effect of the paper sizing agent composition of the present invention is that when a vinyl monomer is polymerized or copolymerized in the presence of an alkyl mercaptan having 6 to 22 carbon atoms, the alkyl mercaptan used is attached to the end of the resulting polymer. It is thought that this is because the polymer of (bl) acts as an excellent dispersant and protective colloid for the ketene dimer compound represented by the general formula (1).

The internal sizing agent composition for paper manufacturing of the present invention has storage stability, mechanical stability, and size effect regardless of whether the ionicity of the polymer (bl) is nonionic, cationic, anionic, or amphoteric. When used as an internal sizing agent composition for paper manufacturing, its ionicity can be appropriately selected and adjusted according to the type and amount of ionicity of other additives used together. Make it.

The internal sizing method of the present invention is carried out by adding the internal sizing agent composition for paper manufacturing of the present invention to the wet end portion during the paper or paperboard manufacturing process.

Specifically, the papermaking internal sizing agent composition of the present invention was added to an aqueous pulp dispersion at a rate of 0.002% based on the dry weight of the bulb.
-3% by weight solids, preferably 0.005-2% by weight solids.

Valve raw materials include bleached or unbleached chemical pulp such as kraft pulp or sulfide pulp, bleached or unbleached high-yield pulp such as ground wood valves, mechanical pulp or thermomechanical valves, new and old used paper, used magazine paper, used corrugated paper, or tax ink. Any waste paper valve, such as 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. Starch, polyvinyl alcohol, dye, coating color, surface sizing agent, anti-slip agent, etc. may be applied as necessary.

EXAMPLES The present invention will be described in detail below. In the present invention, % means parts by weight.

Example 1 12.58 g of dimethylamine ethyl methacrylate), 213.9 g of a 50% aqueous solution of acrylamide, and 2.08 g of itaconic acid were placed in a 1Z four-bottle flask equipped with a stirrer, a temperature needle, a reflux condenser, and a nitrogen gas inlet tube. , ion exchanger m water 166,7 g, isopropyl alcohol 2
12.8g and n-dodecyl mercaptan 1.62
g was prepared, and the pt+ was adjusted to 4.0 with a 20% aqueous sulfuric acid solution. While stirring this mixture, nitrogen gas was introduced,
After removing oxygen, the temperature was raised to 60°C. At 60°C, 3.65 g of a 5% aqueous solution of ammonium persulfate was added to initiate polymerization. After that, the temperature was raised to 78℃, and the temperature was increased to 78℃ for 1.5 hours.
After being maintained at 1°C, a 5% aqueous solution of ammonium persulfate was added.
Added 10g. After maintaining the same temperature for an additional hour,
200 g of ion-exchanged water was added and distillation of isopropyl alcohol was started. Two hours after the start of distillation, 271.5 g of a mixed distillate of isopropyl alcohol and water was obtained, and the distillation was completed. Ion-exchanged water 71 was added to the obtained polymerization product.
．． Add 5g, nonvolatile content 20.4%, 25°C, 6 min.
Bruch Field viscosity (hereinafter referred to as viscosity) measured at 0 rotations 420 centipoise (hereinafter referred to as cps),
An aqueous polymer solution P-1 of pl(4,6) was obtained.

Next, 100 parts of a ketene dimer compound (made from a mixture of 40% palmitic acid chloride and 60% stearic acid chloride), 98 parts of the polymer aqueous solution P-1 obtained by the polymerization, and 28 parts of ion-exchanged water were added.
Two parts were heated to 70° C. and preliminarily dispersed in a homomixer, and then passed through a high-pressure discharge type homogenizer twice under a shear pressure of 250 g/clJ while maintaining the same temperature to uniformly disperse the mixture. After cooling by adding ion-exchanged water appropriately, 32
The mixture was filtered through a 5-mesh wire mesh to obtain an internal sizing agent composition for paper manufacturing E-1, which was an aqueous dispersion. This papermaking internal sizing agent composition E-1 has a nonvolatile content of 20.2% and a viscosity of 15.4.
cps XpH 3.5.

In order to examine the storage stability of the paper-making internal sizing agent composition E-1, it was stored at 32° C. for one month and changes in viscosity over time were examined. In addition, in order to examine mechanical stability, a stability test was conducted using a Marlon method stability tester. The results of storage stability and mechanical stability are shown in Table 2.

Examples 2 to 13 Types of mercaptans and compositions of vinyl monomers are shown in Table 1.
Polymerization was carried out in the same manner as in Example 1, except for changing the formulation shown in , to obtain aqueous polymer solutions P-2 to P-13. Note that the amount of isopropyl alcohol for viscosity adjustment was changed as appropriate each time. Example 1 except that the blending ratio of ketene dimer compound/the above polymer was changed as shown in Table 2.
Paper sizing agent compositions E-2 to E-1 were prepared in the same manner as above.
The storage stability and mechanical stability of each of these samples were examined in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Examples 1-5 Polymer aqueous solutions RP-1-
RP-5 was obtained, and papermaking sizing agent compositions RE-1 to RE-5 were obtained in the same manner using this, and the storage stability and mechanical stability were investigated in the same manner. Table 2 shows the results.

Note that the symbols in Table 1 indicate the following.

M-1; n-dodecyl mercaptan M-2; n-octyl mercaptan M-3; tert-dodecyl mercaptan 4; n-hexadecyl mercaptan M-5; n-octadecyl mercaptan; n-butyl mercaptan door; thiophenol C-1; dimethylaminoethyl methacrylate C-2
; Quaternization product C-3 of C-1 with methyl chloride;
Dimethylaminopropyl acrylamide C-4; Dimethylaminopropyl methacrylamide A-1; Itaconic acid A-2; Maleic acid A-3; Acrylic acid comparative examples 6 to 8 Paper manufacturing internal additive size containing commercially available ketene dimer compounds Table 2 shows the results of examining the physical properties, storage stability, and mechanical stability of three types of agents (RE-6 to RE-8) as comparative examples.

(Margins below this page) Table 1 (Composition and ml of the above Cb polymer aqueous solution) Table 2
(Formulation, physical properties, storage stability and mechanical stability of internal sizing agent composition for paper manufacturing In Table 2, the ketene dimer compound is made from a mixture of 40% palmitic acid chloride and 60% stearic acid chloride, The polymer aqueous solution is as shown in Table 1, and the storage stability is the viscosity after being stored at 32°C for one month.The mechanical stability was determined by testing 50g of the internal sizing agent composition for paper manufacturing using the Marlon method stability test. In the machine, under a load of 20Kg/d, rotation speed 1000 r
This is the weight of the solids that did not pass through a 100-mesh wire mesh when stirred at pm for 10 minutes. The test starting temperature is 25
It is ℃. The higher the solid weight, the more lees are generated, which indicates that the mechanical stability is poor.

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

[Test Example 1] Pulp slurry (LBKP, Canadian Standard Freeness 400mf) with a concentration of 2.4% was sequentially mixed with 0.5% of sulfate band and 0.3% of cationized starch (Ecate F, Tamago National Co., Ltd. 1). Added and stirred for 2 minutes.
Then, after diluting the pulp slurry concentration to 0.24%,
Paper manufacturing internal sizing agent compositions E-1 to E-6 and RE-1 obtained in Examples 1 to 6 and Comparative Examples 1.2.5 to 8
, RE-2, I? 0.15 each of E-5 to RE-8
% and after stirring for 1 minute, 20% of light calcium carbonate (Tama Pearl 121, manufactured by Okutama Kogyo Co., Ltd.) was added, and after stirring for 1 minute, 0.02% of an anionic retention improver (Hyretin 501, manufactured by Dick Vercules) was added. and stirred for 1 minute. Using the paper stock obtained in this way, a basis weight of 70 g/
rd wet paper was obtained. Note that the papermaking pH was 8.0. This wet paper was pressed until the moisture content reached 58.0%, and then dried with a drum dryer at 80° C. for 70 seconds. Immediately after drying, paper with a moisture content of 3.5% was obtained. This paper at 20℃
After conditioning the humidity in an atmosphere with a relative humidity of 65% for 24 hours, the Steckigt sizing degree 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.

[Test Example 2] 0.5% sulfuric acid bandate and 0.3% cationized starch (Kate F, manufactured by Tamago Nassinal Co., Ltd.) were added to pulp slurry (LBKP, Canadian Standard Freeness 400 μl) with a concentration of 2.4%. The internal sizing agent compositions for paper manufacturing obtained in Examples 7 to 13 and Comparative Examples 3 to 8 were added sequentially and stirred for 2 minutes. After diluting the pulp slurry concentration to 0.24%, each of the internal sizing agent compositions for paper manufacturing obtained in Examples 7 to 13 and Comparative Examples 3 to 8 was added. 16% and 0.02% of a cationic retention improver (Hyretin 501, manufactured by Dick Vercules) were added and stirred for 1 minute. Using the paper stock thus obtained, the same procedure as in Test Example 1 was carried out. The Steckigt sizing degree of handmade paper with a basis weight of 70 g/g was measured.The results are shown in Table 4.

From the above results, it can be seen that the paper-making internal sizing agent composition of the example has excellent storage stability and mechanical stability, and the internal sizing method using the same shows excellent sizing effects.

Effects of the Invention According to the present invention, a polymer obtained by polymerizing or copolymerizing a vinyl monomer in the presence of an alkyl mercaptan having 6 to 22 carbon atoms is used in combination with a ketene dimer compound, so that an internal sizing agent composition for paper manufacturing can be prepared. It has excellent storage stability and mechanical stability, and the internal addition sizing method using it can exhibit excellent sizing effects.

Procedural amendment written on April 1, 1983 (spontaneous) June 28, 1999 Commissioner of the Japan Patent Office Yoshi 1) Tsuyoshi Moon 1, Indication of the case 1988 Patent Application No. 104204 2, Name of invention for paper manufacturing Internal additive sizing agent composition and internal additive sizing method 3, relationship with the case of the person making the amendment Patent applicant 3-7-20 Nihonbashi, Chuo-ku, Tokyo Representative Difuku Vercules Co., Ltd. Representative Kawai - line 4, agent ■105 5. Date of amendment order Voluntary 6. Number of claims increased by amendment None 7. Target of amendment "Claims in the specification""Detailed description of the invention in the specification" 8. Contents of the amendment (1) "2. Scope of claims" from page 1, line 5 to page 2, line 12 of the specification is corrected as shown in the attached sheet.

(2) On page 6, line 12 of the specification, the phrase "a copolymer of, or" is corrected to "a copolymer of, or a copolymer of acrylamide and an anionic vinyl monomer, or."

(3) On page 25, line 9 of the specification, It says "Hiretin 501", Corrected to "Hiretin 104."

Otsu * Wif desired range < 1) (Al A ketene dimer compound represented by the following general formula (1), (wherein, [21, !22 are the same or different carbon numbers 8 to 3
(represents a hydrocarbon group of 0) (bl) Contains a polymer obtained by polymerizing or copolymerizing a vinyl monomer in the presence of an alkyl mercaptan having 6 to 22 carbon atoms, and (b
1. An internal sizing agent composition for paper manufacturing, characterized in that it contains 2 to 100 parts by weight of a polymer.

(2) Internal additive size for paper manufacturing according to claim 1, characterized in that the alkyl mercaptan having 6 to 22 carbon atoms in the above) is present in an amount of 0.01 to 10 mol % based on the vinyl monomer. agent composition.

(3) The +'bl polymer is a polymer of acrylamide, a copolymer of acrylamide and a cationic vinyl monomer, or a copolymer of acrylamide and a/)+J)Li
3. The internal sizing agent composition for paper manufacturing according to claim 1 or 2, which is a copolymer of polyamide, cationic vinyl heptamer, and anionic vinyl hetamine.

(4) A method for internally adding sizing characterized by using the internally adding sizing agent composition for paper manufacturing according to any one of claims 1 to 3.

Claims (4)

[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) Contains a polymer obtained by polymerizing or copolymerizing a vinyl monomer in the presence of an alkyl mercaptan having 6 to 22 carbon atoms, and (b) per 100 parts by weight of the compound (a).
An internal sizing agent composition for paper manufacturing, characterized in that it contains 2 to 100 parts by weight of a polymer. (2) The alkyl mercaptan having 6 to 22 carbon atoms in the above (b) is 0.01 to 10% relative to the vinyl monomer.
The internal sizing agent composition for paper manufacturing according to claim 1, characterized in that the composition is present in an amount of mol %. (3) The polymer in (b) above is a polymer of acrylamide, a copolymer of acrylamide and a cationic vinyl monomer, or a copolymer of acrylamide, a cationic vinyl monomer, and an anionic vinyl monomer. An internal sizing agent composition for paper manufacturing according to claim 1 or 2. (4) A method for internally adding sizing characterized by using the internally adding sizing agent composition for paper manufacturing according to any one of claims 1 to 3.