JP4359908B2 - Alkenyl succinic anhydride emulsion sizing agent, method for producing the same, and paper containing the sizing agent - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an alkenyl succinic anhydride emulsion sizing agent, Its manufacturing method, andFor paper containing the sizing agent, reduce papermaking stains when producing paper in the neutral range,Can improve emulsion stability and sizeI will provide a.
[0002]
BACKGROUND OF THE INVENTION
In recent years, from the standpoint of preventing deterioration during storage of paper, there has been an increase in production orientation toward neutral paper.
Conventionally, alkenyl succinic anhydride and alkyl ketene dimer (AKD) are commonly used as sizing agents for the production of neutral paper, but AKD sizing agents are paper-making stains, paper slips, or Problems such as slow rise in size remain.
In addition, with the recent method using a neutral rosin sizing agent, there remains a problem that it is difficult to obtain a high sizing property when the pH of the papermaking system is 7.0 or more, or when calcium carbonate is frequently used as a filler. ing.
[0003]
[Prior art]
On the other hand, there are various conventional techniques for paper making using alkenyl succinic anhydride sizing agents.
First, Japanese Patent Publication No. 53-36044 discloses that an alkenyl succinic anhydride is emulsified and dispersed with an emulsifier such as polyoxyalkylene alkyl, polyoxyalkylene alkyl aryl ether, or a corresponding mono- or diester immediately before addition. A method for producing an emulsion and adding it to a papermaking system is disclosed.
[0004]
Further, as a conventional technique using a cationic polymer as an emulsifier for alkenyl succinic anhydride, JP-A-60-246893 discloses a water-soluble cationic vinyl addition polymer having a molecular weight of at least 10,000 as a cationic polymer. JP-B-6-33597 discloses a method using a cationic (meth) acrylamide polymer together with a water-in-oil surfactant, and JP-A-9-111692 discloses (meth) acrylamide. A method is disclosed in which a grafted cationic starch obtained by graft-polymerizing monomers containing a cationic polymer is used as a cationic polymer.
[0005]
Furthermore, as a conventional technique using an amphoteric polymer for emulsifying and dispersing alkenyl succinic anhydride, Japanese Patent Publication No. 3-4247 discloses alkenyl succinic anhydride in the presence of a mixture of a specific amphoteric acrylamide polymer and a cationic starch. A method of emulsifying and dispersing succinic anhydride in water and neutral papermaking using the obtained emulsion is disclosed, Japanese Patent Application Laid-Open No. 58-45731, Japanese Patent Publication No. 6-72395, and Japanese Patent Application Laid-Open No. 6-116894. In addition, alkenyl succinic anhydride is disclosed in JP-A-6-128896 or JP-A-6-166985 in the presence of an amphoteric acrylamide polymer and a surfactant such as polyoxyethylene alkyl ether sulfate. A method of emulsifying and dispersing in water is disclosed.
[0006]
[Problems to be solved by the invention]
In the above prior art method, the composition mismatch of the alkenyl succinic anhydride, the cationic species of the cationic polymer, the content thereof and the presence of the surfactant, or the emulsification method of the alkenyl succinic anhydride and the cationic polymer For reasons such as incompatibility, a paper with high sizing properties cannot be obtained even if paper making using a small amount of the alkenyl succinic anhydride sizing agent of the prior art, and the sizing agent should be added in order to improve sizing properties. If it increases, it will cause papermaking stains.
In addition, these alkenyl succinic anhydride emulsions have poor stability, are prone to hydrolysis after emulsification, and have problems such as increased papermaking stains due to the hydrolyzed sizing agent.
[0007]
The present invention is an alkenyl succinic anhydride-based aqueous emulsion sizing agent that improves emulsification stability, reduces papermaking stains in the neutral range, and imparts excellent sizing properties to the paper. As an objective.
[0008]
[Means for Solving the Problems]
  The inventors haveBy emulsifying and dispersing both the alkenyl succinic anhydride and the amphoteric (meth) acrylamide polymer aqueous solution to a specific species, it is possible to ensure both good emulsification stability and size, and in that case, When emulsified and dispersed with a rotary emulsifier, an emulsion with an appropriate average particle size can be obtained, and emulsion dispersibility and size can be further improved while reducing papermaking stains.Thus, the present invention has been completed.
[0009]
  That is, the present invention 1 is an alkenyl succinic anhydride emulsion sizing agent containing an alkenyl succinic anhydride and an amphoteric (meth) acrylamide polymer aqueous solution.
  The alkenyl succinic anhydride has 60 to 85% by weight of an internal olefin having a double bond inside from the α-position having 16 carbon atoms and 18 carbon atoms.Has double bond inside from α-positionMaleic anhydride is added to a mixed olefin composed of 40 to 15% by weight of an internal olefin,
  The amphoteric (meth) acrylamide polymer comprises quaternary ammonium group-containing cationic (meth) acrylamide 3.0 to 5.0 mol%, α, β-unsaturated dicarboxylic acid 0.2 to 3.0 mol%, An alkenyl succinic anhydride emulsion sizing agent characterized by being a copolymer of mixed monomers composed of 92.0 to 96.8 mol% of (meth) acrylamide.
[0011]
  Invention 2 provides the invention 1 described above.In which the molecular weight of the amphoteric (meth) acrylamide polymer is 10,000 to 500,000.
[0012]
  Invention 3 is the invention 1 or 2 described above.In the absence of a surfactant, 10 to 50 parts by weight of an amphoteric (meth) acrylamide polymer aqueous solution as a solid content is contained with respect to 100 parts by weight of alkenyl succinic anhydride.CharacterizeAn alkenyl succinic anhydride emulsion sizing agent.
[0013]
  Invention 4 provides the above Inventions 1-3.In any of the above, an alkenyl succinic anhydride emulsion sizing agent characterized in that the average particle size of the emulsion is 0.7 to 1.3 μm.
[0014]
  The present invention 5The alkenyl succinic anhydride and the amphoteric (meth) acrylamide polymer aqueous solution are passed through a high shear rotary emulsifier,Any of the present inventions 1 to 4A method for producing an alkenyl succinic anhydride emulsion sizing agent comprising:
  The high shear rotary emulsifier includes a stator in which a plurality of annular bodies are concentrically fixed on the emulsifier body side, and a rotor in which the plurality of annular bodies are concentrically fixed on the rotation shaft side of the emulsifier. High shear generated between the stators of the high-shear rotary emulsifier and the rotors rotating at high speed, with a plurality of annular bodies of the stator and the rotor being inserted and arranged in a staggered stack. An alkenyl succinic anhydride emulsion sizing method is characterized in that an alkenyl succinic anhydride is emulsified and dispersed in water by force.
[0015]
  The present invention 6 includes the above present inventions 1-4.Any of the alkenyl succinic anhydride emulsion sizing agent and calcium carbonate contained in a pulp slurry and wet-made.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention, first,A specific alkenyl succinic anhydride obtained by reacting a predetermined mixed olefin with maleic anhydride, a quaternary ammonium group-containing cationic (meth) acrylamide, an α, β-unsaturated dicarboxylic acid, etc. An alkenyl succinic anhydride emulsion sizing agent containing an amphoteric (meth) acrylamide polymer aqueous solution,Second, givenBy passing through a high shear rotary emulsifierAlkenyl succinic anhydride emulsion sizing agentHow to manufactureAnd third,thisA paper containing a sizing agent as an internally added sizing agent.
  In addition, (meth) acrylamide is a superordinate concept including both acrylamide and methacrylamide.
[0018]
  The alkenyl succinic anhydride (ASA) is obtained by adding maleic anhydride to various olefins (including propylene, butene oligomers, etc.), specifically, hexadecenyl succinic anhydride. , Heptadecenyl succinic anhydride, octadecenyl succinic anhydride, tetrapropenyl succinic anhydride, triisobutenyl succinic anhydride, 1-methyl-2-pentadecenyl succinic anhydride, etc. AlthoughThe ASA of the present invention is16 carbon atoms (ie, C₁₆) From 60 to 85% by weight of an internal olefin having a double bond inside from the α-position, and having 18 carbon atoms (ie, C₁₈) Produced by adding maleic anhydride to a mixed olefin containing 40 to 15% by weight of the same internal olefin.
  C₁₅When maleic anhydride is added to the following olefins, or when maleic anhydride is added to olefins other than the above composition, the stability after emulsification becomes poor or the size property is lowered. In addition, when a so-called α-olefin having a double bond position at the α-position is used as a raw material, the product becomes a solid or is inferior in size, so that the olefin has an internal olefin having a double bond inside the α-position. Is preferred.
[0019]
In addition, in a normal reaction in which maleic anhydride is added to a mixed olefin, a colored component and a high molecular weight by-product are produced. However, when this component exceeds 1% by weight, the sizing property is reduced. For example, GPC (Gel Permeation chromatography (gel permeation chromatography), a purified ASA having a high molecular weight component of 1% by weight or less than the main ASA is preferred. ASA is purified to 1 wt% or less by distillation, adsorption removal, or other conventional methods.
[0020]
On the other hand, the amphoteric (meth) acrylamide polymer aqueous solution is obtained by copolymerizing (meth) acrylamide, a cationic monomer and an anionic monomer, or another monomer, or applying a Hofmann decomposition reaction or a Mannich reaction to this copolymer. Later, a cationic group or an anionic group is introduced, or a cationic group and an anionic group are introduced into poly (meth) acrylamide.
Preferably, quaternary ammonium group-containing cationic acrylamide monomer (3.0 to 5.0 mol%), α, β-unsaturated dicarboxylic acid (0.2 to 3.0 mol%) and (meth) acrylamide 92. It is an amphoteric (meth) acrylamide polymer aqueous solution composed of a copolymer of mixed monomers containing 0 to 96.8 mol%.
The molecular weight of the amphoteric polymer is preferably 10,000 to 500,000.
[0021]
Examples of the quaternary ammonium group-containing cationic acrylamide monomer include (meth) acrylamidopropyltrimethylammonium chloride, (meth) acrylamidopropyldimethylbenzylammonium chloride, (meth) acrylamidopropyldiethylbenzylammonium chloride, 2-hydroxy- Examples include 3- (meth) acrylamidopropyltrimethylammonium chloride.
With cationic groups other than the quaternary ammonium group, ASA after emulsification is easily hydrolyzed, or the fixing property of ASA to fibers when added to a pulp slurry is poor.
When the content of the quaternary ammonium group-containing cationic acrylamide monomer is less than 3.0 mol%, the fixing property of the ASA to the fiber when added to the pulp slurry is inferior, and conversely, 5.0 mol%. Exceeding this is not preferable because the hydrolysis of ASA after emulsification is accelerated.
[0022]
Examples of the α, β-unsaturated dicarboxylic acid include itaconic acid, fumaric acid and maleic acid, and itaconic acid is more effective.
When the content of α, β-unsaturated dicarboxylic acid is less than 0.2 mol%, the effect of emulsification is low, and conversely, when it exceeds 3.0 mol%, the size is inferior. Moreover, when monocarboxylic acid is used, size property is inferior.
[0023]
As a method for synthesizing the above amphoteric (meth) acrylamide polymer aqueous solution from a quaternary ammonium group-containing cationic acrylamide monomer, α, β-unsaturated dicarboxylic acid and (meth) acrylamide, three compounds as these constituent monomers are used. By mixing water and water, adding initiators and heating to polymerize, dropping monomers and initiators into heated water for polymerization, or other common aqueous solution polymerization methods Synthesized.
Examples of the initiators include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, peroxides such as hydrogen peroxide, azo initiators such as azoisobutyronitrile, or redox initiators. Is used.
As described above, the molecular weight of the amphoteric polymer is preferably 10,000 to 500,000, and if it exceeds 500,000, the emulsifying property of ASA is lowered. The molecular weight can be adjusted by adding an aqueous chain transfer agent or alcohol, or controlling the polymerization temperature.
[0024]
  Invention 5Is a method for producing an alkenyl succinic anhydride emulsion sizing agent through a predetermined high-shear rotary emulsifier in order to promote improvement in emulsion stability and size.
  The high-shear rotary emulsifier includes a stator in which a plurality of annular bodies are concentrically fixed on the emulsifier body side, and a rotor in which the plurality of annular bodies are concentrically fixed on the rotation shaft side of the emulsifier. A plurality of annular bodies of the stator and rotor are inserted and arranged opposite each other in a stacked manner, and ASA is emulsified in water by the high shear force generated between the annular bodies of the stator and the rotor rotating at high speed. It is an emulsifying machine in the form of dispersion. Specifically, it has the same structure such as Ultra Tarlux, Dispacks Reactor (both manufactured by IKA), Ebara Milder (manufactured by Ebara Seisakusho), Cavitron (manufactured by CAVITRON). An emulsifier having
[0025]
The basic structure of the high-shear rotary emulsifier will be described with reference to FIG. 4. The emulsifier 1 includes an emulsifier body 10 and a lid 11 detachably fixed to the emulsifier body 10 with a fastener 9. The generator unit 8 including the stator 2 and the rotor 3 is formed facing the emulsification chamber 6 of the emulsifier body 10. The stator 2 is provided on the lid 11, and the rotor 3 is provided on the emulsifier body 10. The rotor 3 is linked to an electric power source (not shown).
A three-layer comb-shaped annular body 4 is concentrically fixed to the stator 2, and similarly, a three-layer comb-shaped annular body 5 is concentrically fixed to the rotor 3. The tooth-shaped annular body 4 and the comb-shaped annular bodies 5 of the rotor 3 are inserted and arranged in a staggered stack so as to face each other.
The ASA and the amphoteric polymer aqueous solution fed into the emulsification chamber 6 from a carry-in path (not shown) provided in the emulsifier body 10 of the high shear type rotary emulsifier 1 are supplied to the stator 2 and the rotor 3 rotating at high speed. In response to the high shearing force in the circumferential direction generated in the gap between the comb-shaped annular bodies 4 and 5, or in addition to this, the cavitation action results in an emulsion having an appropriate particle size and particle size distribution. It is unloaded from the unloading path 7 of the machine body 10.
[0026]
The high-shear rotary emulsifier of the present invention is basically intended for emulsification in one pass, and the generator unit 8 in which the stator 2 and the rotor 3 are combined has an emulsification chamber as shown in FIG. Only one pair may be provided in 6 or a plurality of pairs may be provided in series. When the logarithm of the generator unit 8 is increased, the emulsification efficiency in one pass is improved.
Moreover, as a form of the annular bodies 4 and 5 provided in the stator 2 and the rotor 3, any structure may be used as long as the annular bodies 4 and 5 arranged to face each other are engaged with each other in a plurality of layers. The shape of the annular bodies 4 and 5 itself is not limited to the comb-teeth shape, and may be a simple cylindrical body or a cylindrical body having various shapes of through holes such as round holes and slits in the peripheral wall.
In the emulsification method using the high shear type rotary emulsifier, a method of supplying a mixed solution of ASA and amphoteric polymer to the emulsifier is common, but it is also possible to separately supply ASA and amphoteric polymer to the emulsifier. it can.
[0027]
Incidentally, homogenizers, homomixers, line mixers, or colloid mills, which have the basic principle of emulsifying and dispersing resin particles between a fixed-side blade and a high-speed rotating stirring blade, emulsify with mechanical shearing force. Although it is common to the high shear type rotary emulsifier of the present invention in terms of dispersion, on the other hand, a plurality of annular bodies of the stator and the rotor mesh with each other so as to be opposed to each other and mesh with each other. However, it is fundamentally different from the high-shear rotary emulsifier of the present invention in that it does not have a structure for generating a shearing force.
Therefore, compared with known homogenizers, homomixers, line mixers, ultrasonic emulsifiers, or orifice type emulsifiers, the high shear type rotary emulsifier of the present invention is not too strong when emulsifying ASA. Thus, an emulsion having an appropriate average particle size and a relatively narrow emulsified particle size distribution can be obtained. For this reason, there are fewer large-sized particles and extremely small particles that do not act effectively, all of the ASA used can be effectively emulsified, and a neutral paper with a high size can be obtained with a small amount of ASA added. .
[0028]
As the content of ASA and amphoteric (meth) acrylamide polymer at the time of emulsification, 10 to 50 parts by weight of an amphoteric polymer aqueous solution as a solid content is mixed with 100 parts by weight of ASA without containing a surfactant. It is effective to emulsify and disperse the average particle diameter of ASA to 0.7 to 1.3 μm using the high shear rotary emulsifier.
If the content of the amphoteric polymer aqueous solution is less than 10 parts by weight as a solid content, the emulsion particle size is increased and the stability of the emulsion is lowered. On the other hand, when the content exceeds 50 parts by weight, the size of the paper obtained using this emulsion is inferior.
In the emulsification step, as described above, it is preferable to emulsify and disperse without using a surfactant. When a surfactant is used, an emulsion having an extremely small particle size increases and ASA is hydrolyzed. This is because it becomes easy and does not act effectively as a sizing agent.
When ASA and an amphoteric polymer aqueous solution are emulsified using a high-shear rotary emulsifier, the average particle size is preferably 0.7 to 1.3 μm, more preferably 0.9 to 1.2 μm.
This is because when the average particle size is 0.7 μm or less, hydrolysis tends to occur, and fixing to pulp fibers becomes poor in a papermaking system, and size properties are lowered. On the contrary, if the average particle size is 1.3 μm or more, the stability of the emulsion is deteriorated, the size property is lowered, and the papermaking stain is caused.
[0029]
  Invention 6In the presence of calcium carbonate, an inexpensive filler,Inventions 1-4This paper was made by neutral wet papermaking by adding an ASA emulsion sizing agent as an internal sizing agent to a pulp slurry.
  The pulp fibers that make up the pulp slurry include wood pulp and deinked pulp (DIP) such as NBKP and LBKP that are usually used for papermaking, linter pulp, hemp, bagasse, kenaf, esparto grass, straw, etc. Semi-synthetic fibers such as non-wood pulp, rayon and acetate, or synthetic fibers such as polyolefin, polyamide and polyester can be used.
  It goes without saying that fillers other than calcium carbonate, dyes, paper strength enhancers, yield improvers, antifoaming agents, and the like can be added to the pulp slurry as necessary.
  Paper obtained by wet papermaking is a broad concept including printing / writing / graphic paper such as electrophotographic paper, ink jet paper, newspaper, packaging paper, thin paper, hybrid paper, paperboard, cardboard, and the like.
[0030]
[Action]
Specified amphoteric (meta) obtained by copolymerizing a specific ASA obtained by reacting a predetermined mixed internal olefin and maleic anhydride with a quaternary ammonium group-containing cationic (meth) acrylamide and an α, β-unsaturated dicarboxylic acid. ) In the alkenyl succinic anhydride emulsion sizing agent obtained by emulsifying and dispersing an aqueous solution of acrylamide polymer, the emulsification stability and the fixability to pulp are increased, and the sizing property can be effectively improved. .
  on the other hand,When the above-mentioned specific ASA and an amphoteric (meth) acrylamide polymer aqueous solution are emulsified and dispersed using a high-shear rotary emulsifier, the stator and rotor of the emulsifier are alternately inserted between a plurality of layers of annular bodies. The resulting shear force gives an emulsion with an appropriate average particle size, and the particle size distribution of the emulsion is also in a relatively narrow range, so the emulsion is difficult to hydrolyze and settles smoothly on pulp fibers. Thus, it can be estimated that the emulsion stability and size are further improved. However, if both ASA and the amphoteric polymer are specialized as described above, the emulsion stability and size can be improved even in a situation where the model of the emulsifier is not selected.
[0031]
【The invention's effect】
When both ASA and the amphoteric polymer are specified and emulsified and dispersed, as shown in the test examples described later, the stability and size of the emulsion can be improved even under conditions where the selection of the emulsification model is separated.
Further, when this specific ASA and an amphoteric (meth) acrylamide polymer aqueous solution are emulsified and dispersed using a high shear type rotary emulsifier, the emulsion has an appropriate emulsified particle size and a relatively narrow particle size distribution. Even with the use of a small amount of sizing agent, papermaking stains can be reduced, high-size paper can be obtained smoothly, and emulsion stability and size can be further improved.
  Furthermore, when a surfactant is used for emulsifying and dispersing ASA, the particle size of the emulsion is reduced, and it is susceptible to hydrolysis, resulting in a decrease in size. However, in the present invention, a surfactant is used. Therefore, there is no such harmful effect.
[0032]
【Example】
Hereinafter, a synthesis example of an aqueous solution of an amphoteric (meth) acrylamide polymer, a production example of an ASA emulsion sizing agent using the amphoteric polymer, and a sizing test example of neutral paper internally sized with the sizing agent will be sequentially described.
Further, “parts” and “%” in the following synthesis examples, examples and test examples refer to “parts by weight” and “% by weight” unless otherwise specified.
It should be noted that the present invention is not limited to the following examples and test examples, and can be arbitrarily modified within the scope of the technical idea of the present invention.
[0033]
<< Synthesis example of aqueous solution of amphoteric (meth) acrylamide polymer >>
Therefore, first, in the absence of a surfactant, a quaternary ammonium group-containing cationic (meth) acrylamide, α, β-unsaturated dicarboxylic acid, and (meth) acrylamide are mixed as a constituent monomer at a specific ratio. Synthesis Examples 1 to 4 of various amphoteric (meth) acrylamide polymer aqueous solutions produced by copolymerizing the mixed monomers are shown below.
[0034]
(1) Synthesis example 1
In a 1 L four-necked flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube, 460 g of water, 20.3 g of 75% aqueous solution of acrylamidopropyltrimethylammonium chloride, 1.5 g of itaconic acid, and 50% of acrylamide 250 g of an aqueous solution and 2.5 g of thioglycerol were added, and nitrogen gas was blown to replace the air in the flask.
The inside of the flask was heated to 50 ° C. with stirring, 2.5 g of 8% aqueous ammonium persulfate solution was added, and then 1.8 g of 3% aqueous sodium bisulfite solution was added, and the temperature rose to 90 ° C. in 20 minutes.
Then, after aging for 60 minutes, it was cooled and diluted with water to a concentration of 20%.
When the synthesized aqueous polymer solution was measured with an aqueous GPC detector (LS-8000; manufactured by Tosoh Corporation), the molecular weight was 210,000.
[0035]
(2) Synthesis Examples 2-4
Based on Synthetic Example 1, each monomer species and content are changed as shown in FIG. 1 and reacted under the same conditions as in Synthetic Example 1 to produce the amphoteric (meth) acrylamide polymer aqueous solutions of Synthetic Examples 2-4. Got.
[0036]
Therefore, an ASA emulsion obtained by emulsifying and dispersing the various amphoteric polymers of Synthesis Examples 1 to 4 and various ASAs (that is, the following types (a) to (c) types of ASA) through a high shear force type rotary emulsifier. Examples 1 to 5 and Comparative Examples 1 to 4 of the sizing agent are shown.
In the GPC measurement of ASA, Shodex GPC SYSTEM-21H was used.
[0037]
Example 1
Addition of maleic anhydride to a mixed olefin containing 80% of internal olefins having 16 carbon atoms and 18% of internal olefins having 18 carbon atoms, followed by distillation to contain high molecular weight by-products as measured by GPC A kind of ASA (a), which was purified to an amount of 0.5% or less, was produced.
Then, the generator parts of the above-mentioned ASA (a) and the amphoteric polymer aqueous solution of Synthesis Example 1 are arranged in three pairs in series under two conditions of 100 g / min and 75 g / min, respectively, according to the mixing ratio in FIG. The mixture was poured into a high-shear rotary emulsifier (Dispax Reactor; manufactured by IKA) and continuously emulsified.
Thereafter, the emulsion was continuously diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%. The average particle size of the ASA emulsion sizing agent was 1.2 μm.
[0038]
Example 2
The ASA (a) of Example 1 and the amphoteric polymer aqueous solution of Synthesis Example 2 were injected into a high shear rotary emulsifier under the same conditions as in Example 1 according to the mixing ratio shown in FIG. After that, the emulsion was continuously diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%.
The average particle size of the ASA emulsion sizing agent was 0.9 μm.
[0039]
  Example 3
8 g of the ASA (a) of Example 1 above, 8 g of the amphoteric polymer aqueous solution of Synthesis Example 1 and 517.3 g of water were placed in a 1000 mL household mixer (MX-15; manufactured by Matsushita Electric Industrial Co., Ltd.) and stirred for 1 minute. As a result, an emulsion sizing agent having an ASA concentration of 1.5% was obtained. The average particle size of the ASA emulsion sizing agent was 1.2 μm.
[0040]
  《Comparative Example 1》
100 g of ASA (a) of Example 1 above and 100 g of the amphoteric polymer aqueous solution of Synthesis Example 3 were placed in a 500 mL tall beaker, and a rotary stirring type homomixer
(TK homomixer 4C; manufactured by Tokushu Kika Kogyo Co., Ltd.) was emulsified for 2 minutes and then diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%.
The average particle size of the ASA emulsion sizing agent was 2.2 μm.
[0041]
  《Comparative Example 2》
200 g / cm of ASA (b) of Example 3 and 400 g of the amphoteric polymer aqueous solution of Synthesis Example 4 were mixed and mixed with a high-pressure emulsifier (15M-8TA; manufactured by GAULIN). ² After emulsifying with an aqueous solution, it was diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%. The average particle size of the ASA emulsion sizing agent was 0.6 μm.
[0042]
  《Comparative Example 3》
Maleic anhydride was added to the mixed olefin containing 5% of the internal olefin having 16 carbon atoms and 90% of the internal olefin having 18 carbon atoms to produce (c) type ASA. This ASA contained 2.4% of high molecular weight by-product by GPC measurement.
8 g of the above type (c) ASA, 2 g of the amphoteric polymer aqueous solution of Synthesis Example 3 and 523.3 g of water were placed in a 1000 mL household mixer similar to Example 5 and stirred for 1 minute to have an ASA concentration of 1.5%. An emulsion sizing agent was obtained.
The average particle size of the ASA emulsion sizing agent was 1.3 μm.
[0043]
  《Comparative Example 4》
100 g of ASA of type (a) of Example 1 and 400 g of the amphoteric polymer aqueous solution of Synthesis Example 4 were placed in a 1000 mL household mixer similar to Example 5 and stirred for 2 minutes, and then diluted with water to obtain an ASA concentration of 1 Obtained 5% emulsion sizing agent.
The average particle size of the ASA emulsion sizing agent was 1.0 μm.
[0044]
  《Comparative Example 5》
Maleic anhydride was added to the mixed olefin containing 55% of the internal olefin having 16 carbon atoms and 40% of the internal olefin having 18 carbon atoms to produce (b) type ASA. This ASA contained 1.2% of high molecular weight by-product by GPC measurement.
Then, after the above type (b) ASA and the amphoteric polymer aqueous solution of Synthesis Example 2 were injected into the high shear rotary emulsifier under the same conditions as in Example 1 according to the mixing ratio of FIG. The emulsion was continuously diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%.
The average particle size of the ASA emulsion sizing agent was 1.1 μm.
[0045]
  《Comparative Example 6》
The ASA (a) of Example 1 and the amphoteric polymer aqueous solution of Synthesis Example 3 were injected into a high shear rotary emulsifier under the same conditions as in Example 1 according to the mixing ratio shown in FIG. After that, it was continuously diluted with water to obtain an emulsion sizing agent having an ASA concentration of 1.5%.
The average particle size of the ASA emulsion sizing agent was 1.0 μm.
[0046]
  So, aboveExamples 1-3as well asComparative Examples 1-6Using various ASA-based emulsion sizing agents, various neutral papers were produced by wet papermaking using calcium carbonate as a filler, and sizing tests were conducted.
[0047]
<< Sizing Example of Paper Containing ASA Emulsion Sizing Agent >>
Pulp: LBKP C.S.F: 430 ml
After adding 20% of light calcium carbonate (Tama Pearl TP-121; manufactured by Okutama Kogyo Co., Ltd.) with stirring to 2.5% dispersion slurry of the above pulp, gelatinized cationized starch ( Cato102 (manufactured by Nippon NSC Co., Ltd.) was added at 0.8% (absolute dry pulp solid content).
Subsequently, the sulfuric acid band was added by 0.5% (absolute dry pulp amount) and stirring was continued, and each of the ASA emulsion sizing agents in Examples 1 to 5 and Comparative Examples 1 to 4 immediately after emulsification was added to 0.08%. And 0.1% (relative to dry pulp solid content), respectively (see FIG. 3).
Next, 0.05% of a yield agent (Himoloc NR12MLH; manufactured by Hymo Co., Ltd.) is added, and the papermaking pH is adjusted to 7.5 with a square sheet machine according to a conventional method, and papermaking is performed. And dried at 100 ° C. for 90 seconds, with a basis weight of 75 g / m.²Made neutral paper.
The obtained neutral paper is left in a constant temperature / humidity room with a temperature of 20 ° C. and a humidity of 65% for one day to adjust the humidity, and then the sizing degree is determined for each added amount of the sizing agent by the Steecht method (JIS P8122). It was measured.
[0048]
  FIG. 3 shows the test results.
  Examples 1-2 are C₁₆60-85% of internal olefin and C₁₈Specific ASA prepared by reacting 40 to 15% of a mixed olefin with maleic anhydride, 3.0 to 5.0 mol% of a quaternary ammonium group-containing cationic acrylamide and α, β-unsaturated dicarboxylic acid A size obtained by emulsifying and dispersing a specific amphoteric polymer obtained by copolymerizing 0.2 to 3.0 mol% and (meth) acrylamide 92.0 to 96.8 mol% as constituent monomers with a high shear rotary emulsifier. Therefore, the paper made neutral using the sizing agent showed remarkable sizing properties.
Example 3As shown in the above, when the same ASA and the specific amphoteric polymer as in Example 1 are used, the emulsion may be emulsified and dispersed with a household mixer instead of the high shear rotary emulsifier.(In other words, even if the type of emulsifier is not selected)It was confirmed that the neutral paper using the obtained sizing agent also showed good sizing properties according to Examples 1-2.
[0049]
  On the other hand, Comparative Example 1 is similar to Example 1 above.Specific of the present inventionWith ASAUnspecifiedThe size was obtained by emulsifying and dispersing the amphoteric polymer with a homomixer, and the size of the paper using the size was low.
  Comparative Example 2Other than specified in the present invention(B) type ASA, quaternary ammonium group-containing cationic acrylamide 8.0 mol%, α, β-unsaturated dicarboxylic acid 0.5 mol% and (meth) acrylamide 91.5 mol% Copolymerized asOther than specified in the present inventionThe amphoteric polymer was emulsified and dispersed with a high-pressure emulsifier, and the size of the paper using the sizing agent was low.
  Comparative Example 3 is C₁₆5% of internal olefin and C₁₈Contains 2.4% of high molecular weight by-product of 90% internal olefin mixed olefin reacted with maleic anhydrideOther than specified in the present invention(C) species ASA,Other than specified in the present inventionIn Comparative Example 4, the same ASA as in Example 1 and the amphoteric polymer as in Comparative Example 2 were emulsified and dispersed in a household mixer. The size of the paper using Comparative Examples 3 to 4 was low.
Comparative Example 5 is C ₁₆ The internal olefin content is 55% and the high molecular weight by-product containing 1.2% is obtained from the ASA (b) other than specified in the present invention and the amphoteric polymer similar to Example 2 above. Comparative Example 6 is the same ASA as in Example 1, 1.5 mol% of quaternary ammonium group-containing cationic acrylamide and 0.3 mol of α, β-unsaturated dicarboxylic acid. % And a sizing agent obtained from an amphoteric polymer other than those specified in the present invention obtained by copolymerizing 98.2 mol% of (meth) acrylamide as a constituent monomer, and one of the ASA and the amphoteric polymer is the present invention. Since it was specified and emulsified through a predetermined high shear type emulsifier, it showed better size than Comparative Examples 1 to 4, but did not reach Examples 1 to 3 (however, Examples 3 size ( 0.1%) showed a numerical value approximating that of Comparative Example 5 because a household mixer was used instead of a high shear emulsifier.
[0050]
  As aboveIn Examples 1 to 3, in which both ASA and amphoteric polymer are specified by the reactants and compositions, the size can be improved satisfactorily. Also, in this specific condition, as shown in Example 3, the emulsification model has high shear. Even when it was not a mold-rotating emulsifier, it became clear that favorable sizing properties could be secured as compared with Comparative Examples 1-6.
When the above Examples 1-2 and Example 3 are compared, in the emulsification dispersion of a specific ASA and an amphoteric polymer, if the type of the emulsifier is specified as a high shear type rotary emulsifier, the size property is further improved.It became clear.
[Brief description of the drawings]
FIG. 1 is a chart showing the types and mixing ratios of monomers constituting an amphoteric (meth) acrylamide polymer.
[Figure 2]Examples 1-3as well asComparative Examples 1-6It is a graph which shows ASA used for each ASA type | system | group emulsion sizing agent, the kind of amphoteric polymer, a mixing ratio, the kind of emulsifier, etc. FIG.
[Fig. 3]Examples 1-3as well asComparative Examples 1-6It is a graph which shows the result of the sizing test of the neutral paper internally sized with each ASA type | system | group emulsion sizing agent.
FIG. 4 is an exploded perspective view of a main part showing a basic structure of a high shear type rotary emulsifier.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 ... Emulsifier, 2 ... Stator, 3 ... Rotor, 4 ... Comb-shaped annular body of stator, 5 ... Comb-shaped annular body of rotor, 6 ... Emulsification chamber, 7 ... Carry-out path, 8 ... Generator part, 10 ... Emulsifier body, 11 ... lid.

Claims (6)

In an alkenyl succinic anhydride emulsion sizing agent containing an alkenyl succinic anhydride and an amphoteric (meth) acrylamide polymer aqueous solution,
The alkenyl succinic anhydride has 60 to 85% by weight of internal olefin having a double bond inside from the α-position having 16 carbon atoms and 40 to 15 internal olefin having a double bond inside from the α-position having 18 carbon atoms. Maleic anhydride is added to the mixed olefin consisting of wt%,
The amphoteric (meth) acrylamide polymer comprises quaternary ammonium group-containing cationic (meth) acrylamide 3.0 to 5.0 mol%, α, β-unsaturated dicarboxylic acid 0.2 to 3.0 mol%, An alkenyl succinic anhydride emulsion sizing agent characterized by being a copolymer of mixed monomers composed of 92.0 to 96.8 mol% of (meth) acrylamide. 2. The alkenyl succinic anhydride emulsion sizing agent according to claim 1 , wherein the amphoteric (meth) acrylamide polymer has a molecular weight of 10,000 to 500,000. 3. An amphoteric (meth) acrylamide polymer aqueous solution is contained in an amount of 10 to 50 parts by weight as a solid content with respect to 100 parts by weight of an alkenyl succinic anhydride in the absence of a surfactant. An alkenyl succinic anhydride emulsion sizing agent described in 1. The alkenyl succinic anhydride emulsion sizing agent according to any one of claims 1 to 3 , wherein the emulsion has an average particle size of 0.7 to 1.3 µm. The alkenyl succinic anhydride-based emulsion sizing agent according to any one of claims 1 to 4 is produced by passing the alkenyl succinic anhydride and the amphoteric (meth) acrylamide polymer aqueous solution through a high shear rotary emulsifier. A method,
The high shear rotary emulsifier includes a stator in which a plurality of annular bodies are concentrically fixed on the emulsifier body side, and a rotor in which the plurality of annular bodies are concentrically fixed on the rotation shaft side of the emulsifier. High shear generated between the stators of the high-shear rotary emulsifier and the rotors rotating at high speed, with a plurality of annular bodies of the stator and the rotor being inserted and arranged in a staggered stack. A method for producing an alkenyl succinic anhydride emulsion sizing agent comprising emulsifying and dispersing alkenyl succinic anhydride in water by force. A paper made by wet papermaking by adding the alkenyl succinic anhydride emulsion sizing agent according to any one of claims 1 to 4 and calcium carbonate to a pulp slurry.

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