Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
  • C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
  • C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/12—Polymerisation in non-solvents
  • C08F2/16—Aqueous medium
  • C08F2/22—Emulsion polymerisation
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L47/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds; Compositions of derivatives of such polymers
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/10—Coatings without pigments
  • D21H19/14—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
  • D21H19/20—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/56—Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H19/58—Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/50—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by form
  • D21H21/52—Additives of definite length or shape

Definitions

• the present invention relates to a copolymer latex.
• Diene copolymer latex is known as a binder widely used in the paper processing field and carpet backsizing.
• the diene copolymer latex can relatively easily control the change of the monomer composition, the molecular weight of the copolymer, and the like, and can satisfy the required performance of the binder depending on the application.
• a coated paper a styrene-butadiene copolymer latex containing an ethylenically unsaturated carboxylic acid as a polymerization unit as a diene copolymer latex.
• Coated paper is used in a large number of printed materials because of its high printing effect.
• the coated paper is produced by applying a paper coating composition to the surface of a coated base paper and drying it.
• the composition for paper coating is composed of a pigment dispersion in which white pigments such as clay and calcium carbonate are dispersed in water, a binder for adhering and fixing the pigments to each other and the base paper for coating, and other additives. It is a water-based paint.
• the binder in addition to the above-mentioned styrene-butadiene copolymer latex, natural binders such as starch and casein are used.
• the paper coating composition has high fluidity and mechanical stability under high shear, as well as high reusability that can be removed immediately even if it adheres to the backing roll. Dispersibility (roll cleanability) is required. Further, the coated paper is required to have surface strength and the like in order to cope with high-speed printing.
• Patent Document 1 as a method for lowering the latex viscosity, a part of the latex is extracted from the polymerization tank in the middle of the polymerization, and continuously introduced into the polymerization tank again in the final stage of the polymerization.
• a method has been proposed in which the reaction is completed, the particle size distribution of the polymer is widened, and the latex viscosity is lowered.
• Patent Document 2 proposes a method in which a seed latex using a surfactant or the like is obtained, a basic compound is added, and then a specific monomer mixture containing no surfactant is added to perform polymerization. ing.
• Patent Document 3 discloses a method of polymerizing a monomer in the presence of a seed latex having a specific composition and a specific surface carboxylic acid amount.
• Patent Document 2 and Patent Document 3 described above do not satisfy the required low viscosity and high level of quality, and further improvements are required.
• an object of the present invention is a copolymer latex having a low viscosity and good dispersion stability, and when used as a binder for a paper coating composition, the paper coating composition under high shear is used.
• An object of the present invention is to provide a copolymer latex excellent in fluidity and redispersibility and excellent in dry pick strength of the coated paper obtained.
• the copolymer latex of the present invention comprises an aliphatic conjugated diene monomer 20 to 69.5% by weight, an ethylenically unsaturated carboxylic acid monomer 0.5 to 20% by weight, And a copolymer latex obtained by emulsion polymerization of a monomer containing 10.5 to 79.5% by weight of an ethylenically unsaturated monomer copolymerizable therewith, which is bound to latex particles.
• the peak top molecular weight (Mp) obtained by gel permeation chromatography of a non-carboxyl group component is 15,000 or less.
• the copolymer latex of the present invention is preferably obtained by polymerizing a carboxyl group component not bonded to latex particles with a monomer containing an ethylenically unsaturated carboxylic acid monomer as a main component. It is.
• the copolymer latex of the present invention preferably has a detected carboxyl group amount in the range of 0.15 to 1.90 (meq / g) relative to the solid content of the copolymer latex.
• the copolymer latex of the present invention preferably has a number average particle diameter of 30 to 200 nm.
• the copolymer latex of the present invention is preferably used as a binder for paper coating.
• the copolymer latex of the present invention has a low viscosity and good dispersion stability, a paper coating composition excellent in fluidity and redispersibility under high shear can be obtained.
• a coated paper having excellent dry pick strength can be obtained.
• the copolymer latex of the present invention comprises an aliphatic conjugated diene monomer, an ethylenically unsaturated carboxylic acid monomer, and a monomer (single monomer containing an ethylenically unsaturated monomer copolymerizable therewith). Obtained by emulsion polymerization.
• Examples of the aliphatic conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and 2-chloro-1,3-butadiene. Substituted linear conjugated pentadienes, substituted and side chain conjugated hexadienes, and the like. Of these aliphatic conjugated diene monomers, 1,3-butadiene is preferable.
• these aliphatic conjugated diene monomers can be used alone (one kind) or in combination of two or more kinds.
• ethylenically unsaturated carboxylic acid monomer examples include ethylenically unsaturated monocarboxylic acid monomers such as acrylic acid, methacrylic acid, and crotonic acid, for example, ethylenically unsaturated monomers such as maleic acid, fumaric acid, and itaconic acid. Saturated dicarboxylic acid monomer (or its anhydride) etc. are mentioned.
• ethylenically unsaturated carboxylic acid monomers can be used alone (one kind) or in combination of two or more kinds.
• Examples of the ethylenically unsaturated monomer copolymerizable with the above aliphatic conjugated diene monomer and ethylenically unsaturated carboxylic acid monomer include alkenyl aromatic monomers and vinyl cyanide monomers. , Unsaturated carboxylic acid alkyl ester monomers, hydroxyalkyl group-containing unsaturated monomers, unsaturated carboxylic acid amide monomers, and the like.
• alkenyl aromatic monomer examples include styrene, ⁇ -methylstyrene, methyl ⁇ -methylstyrene, vinyl toluene and divinylbenzene.
• styrene is preferable.
• vinyl cyanide monomer examples include acrylonitrile, methacrylonitrile, ⁇ -chloroacrylonitrile, ⁇ -ethylacrylonitrile and the like.
• vinyl cyanide monomers acrylonitrile or methacrylonitrile is preferable.
• unsaturated carboxylic acid alkyl ester monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, glycidyl methacrylate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, and dimethyl itaco. Nate, monomethyl fumarate, monoethyl fumarate, 2-ethylhexyl acrylate and the like.
• methyl methacrylate is preferable.
• Examples of unsaturated monomers containing a hydroxyalkyl group include ⁇ -hydroxyethyl acrylate, ⁇ -hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl Examples include methacrylate, di- (ethylene glycol) maleate, di- (ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis (2-hydroxyethyl) maleate, 2-hydroxyethyl methyl fumarate and the like.
• ⁇ -hydroxyethyl acrylate is preferable.
• Examples of the unsaturated carboxylic acid amide monomer include acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methylol dimethyl acrylamide and the like.
• acrylamide or methacrylamide is preferable.
• any of the monomers used in normal emulsion polymerization such as ethylene, propylene, vinyl acetate, vinyl propionate, vinyl chloride, vinylidene chloride can be used. is there.
• these ethylenically unsaturated monomers can be used alone (one kind only) or in combination of two or more kinds.
• the aliphatic conjugated diene monomer is, for example, 20 to 69.5% by weight, preferably 30 to 60% by weight, based on the total amount of the monomer, and an ethylenically unsaturated carboxylic acid monomer.
• the body is, for example, 0.5 to 20% by weight, preferably 1 to 15% by weight, and the ethylenically unsaturated monomer copolymerizable therewith, for example, 10.5 to 79. 5% by weight, preferably 25 to 69% by weight.
• the dry pick strength of the coated paper is inferior, and when it exceeds 69.5% by weight, the redispersibility of the paper coating composition may be inferior. Yes, the coating operability at the time of creating coated paper may be reduced.
• the mechanical stability and storage stability of the copolymer latex may be inferior.
• the amount of the ethylenically unsaturated carboxylic acid monomer exceeds 20% by weight, the viscosity of the copolymer latex, and thus the viscosity of the paper coating composition, increases, and the copolymer latex is transported by a liquid feed pump. Transportability may be inferior.
• the dry pick strength of the coated paper is significantly reduced.
• an emulsifier and a polymerization initiator are added to the monomer, and the monomer is emulsion polymerized.
• emulsifier examples include sulfate esters of higher alcohols, alkylbenzene sulfonates, alkyl diphenyl ether disulfonates, aliphatic sulfonates, aliphatic carboxylates, dehydroabietic acid salts, formalin condensates of naphthalene sulfonic acid, Anionic surfactants such as sulfate ester salts of ionic surfactants, for example, nonionic surfactants such as alkyl ester type, alkyl phenyl ether type, and alkyl ether type of polyethylene glycol.
• emulsifiers can be used alone (only one type) or in combination of two or more.
• the emulsifier is blended at a ratio of, for example, 0.05 to 8 parts by weight, preferably 0.1 to 3 parts by weight, with respect to 100 parts by weight of the monomer.
• polymerization initiator examples include water-soluble polymerization initiators such as lithium persulfate, potassium persulfate, sodium persulfate, and ammonium persulfate, such as cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, and acetyl peroxide.
• water-soluble polymerization initiators such as lithium persulfate, potassium persulfate, sodium persulfate, and ammonium persulfate, such as cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, and acetyl peroxide.
• oil-soluble polymerization initiators such as oxide, diisopropylbenzene hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.
• potassium persulfate sodium persulfate
• cumene hydroperoxide cumene hydroperoxide
• t-butyl hydroperoxide t-butyl hydroperoxide
• the blending ratio of the polymerization initiator is appropriately adjusted in consideration of the combination of the monomer composition, the pH of the polymerization reaction system, and other additives.
• the polymerization initiator is added in an amount of, for example, 0 to 3 parts by weight, preferably 0.01 to 2 parts by weight, with respect to 100 parts by weight of the monomer.
• a reducing agent and a chain transfer agent can be added as necessary.
• the reducing agent examples include sulfite, bisulfite, pyrosulfite, nithionate, nithionate, thiosulfate, formaldehyde sulfonate (eg, formaldehyde sodium sulfoxylate), benzaldehyde sulfonate, and the like.
• examples thereof include carboxylic acids such as L-ascorbic acid, erythorbic acid, tartaric acid and citric acid and salts thereof, for example, reducing sugars such as dextrose and saccharose, and amines such as dimethylaniline and triethanolamine.
• L-ascorbic acid and erythorbic acid are preferable.
• the reducing agent is added in a ratio of, for example, 0 to 3 parts by weight, preferably 0.005 to 1 part by weight, with respect to 100 parts by weight of the monomer.
• chain transfer agent examples include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan, such as dimethylxanthogen disulfide, diisopropyl Xanthogen compounds such as xanthogen disulfide, for example, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol Phenolic compounds such as allyl compounds such as allyl alcohol, such as halogen such as dichloromethane, dibromomethane, carbon
• chain transfer agents can be used alone (only one kind) or in combination of two or more kinds.
• the chain transfer agent is added at a ratio of, for example, 0 to 3 parts by weight, preferably 0.01 to 2 parts by weight, with respect to 100 parts by weight of the monomer.
• a hydrocarbon solvent can be added as necessary.
• hydrocarbon solvent examples include saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, such as pentene, hexene, heptene, cyclopentene, cyclohexene, cycloheptene, 4-methylcyclohexene, 1-methylcyclohexene.
• unsaturated hydrocarbons such as aromatic hydrocarbons such as benzene, toluene and xylene.
• Cyclohexene and toluene are preferable. Cyclohexene and toluene have a moderately low boiling point and are easy to recover and reuse after the polymerization by steam distillation or the like, and are preferable from the viewpoint of environmental problems.
• additives for example, known additives such as electrolytes such as sodium hydroxide and sodium carbonate, polymerization inhibitors such as hydroquinone, polymerization accelerators, chelating agents, oxygen scavengers, and dispersants may be used as necessary. Can be added.
• electrolytes such as sodium hydroxide and sodium carbonate
• polymerization inhibitors such as hydroquinone, polymerization accelerators, chelating agents, oxygen scavengers, and dispersants may be used as necessary. Can be added.
• the polymerization method of the copolymer latex of the present invention is not particularly limited, and a polymerization method such as one-stage polymerization, two-stage polymerization, or multistage polymerization can be employed.
• a two-stage or more other-stage polymerization method is preferable.
• the balance between the redispersibility of the paper coating composition and the dry pick strength of the coated paper can be further improved.
• addition method of various components is not particularly limited, and a batch addition method, a divided addition method, a continuous addition method, a power feed method, and the like can be used.
• the monomer is divided into a first-stage monomer composition and a second-stage monomer composition.
• the second-stage monomer composition is emulsion-polymerized in the presence of the pre-copolymer.
• the first-stage monomer composition comprises an aliphatic conjugated diene monomer, for example, 5 to 30% by weight, preferably 8 to 27% by weight, an ethylenically unsaturated carboxylic acid monomer, for example, 0.5 to 15% by weight, preferably 1 to 13% by weight, and ethylenically unsaturated monomers copolymerizable therewith, for example 10 to 45% by weight, preferably 15 to 42%. Contains by weight.
• the second-stage monomer composition comprises an aliphatic conjugated diene monomer, for example, 7 to 35% by weight, preferably 15 to 30% by weight, an ethylenically unsaturated carboxylic acid monomer, for example, 0 to 10% by weight, preferably 0 to 8% by weight, and an ethylenically unsaturated monomer copolymerizable therewith, for example, 10 to 25% by weight, preferably 12 to 23% by weight ,contains.
• an aliphatic conjugated diene monomer for example, 7 to 35% by weight, preferably 15 to 30% by weight
• an ethylenically unsaturated carboxylic acid monomer for example, 0 to 10% by weight, preferably 0 to 8% by weight
• an ethylenically unsaturated monomer copolymerizable therewith for example, 10 to 25% by weight, preferably 12 to 23% by weight
• the copolymer latex of the present invention is prepared.
• the peak top molecular weight (Mp) obtained by gel permeation chromatography of the carboxyl group component not bonded to the latex particles is 15,000 or less, preferably 1,000 to 13 , 000. If the peak top molecular weight (Mp) exceeds 15,000, the viscosity of the latex may increase significantly.
• the carboxyl group component not bonded to the latex particle is hydrophilicity generated by polymerization of a monomer containing an ethylenically unsaturated carboxylic acid monomer as a main component on the aqueous phase side in the emulsion polymerization described above. It is a polymer.
• the solvent is swelled into the copolymer latex particles and centrifuged in a state where the specific gravity difference is given, and then the supernatant liquid is obtained. Take out. Subsequently, it measures using the gel permeation chromatograph (GPC) about the taken-out supernatant liquid. Then, based on a calibration curve prepared in advance with a polycarboxylic acid having a known molecular weight, the peak top molecular weight of the chromatogram obtained by GPC is calculated as the peak top molecular weight (Mp).
• GPC gel permeation chromatograph
• the peak top molecular weight (Mp) of the carboxyl group component not bonded to the latex particles can be controlled by appropriately adjusting the polymerization temperature, the type and blending ratio of the chain transfer agent, and the blending ratio of the polymerization initiator. Specifically, the peak top molecular weight (Mp) of the carboxyl group component can be lowered by increasing the polymerization temperature or increasing the amount of radical generation by increasing the amount of the polymerization initiator. Moreover, the peak top molecular weight (Mp) of a carboxyl group component can be lowered
• the detected carboxyl group amount relative to the solid content of the obtained copolymer latex is, for example, 0.15 to 1.90 meq / g, preferably 0.20 to 1.80 meq / g, and more preferably 0.8. 35 to 1.50 meq / g.
• the redispersibility of the paper coating composition and the dry pick strength of the coated paper may be inferior.
• the detected carboxyl group amount exceeds 1.90 the latex viscosity may increase or the viscosity of the paper coating composition may increase.
• the number average particle size of the obtained copolymer latex is, for example, 30 to 200 nm, preferably 30 to 150 nm, and more preferably 50 to 110 nm. When the number average particle diameter is in this range, the dry pick strength of the coated paper is more excellent.
• additives such as antifoaming agents, anti-aging agents, antiseptics, antibacterial agents, flame retardants, and ultraviolet absorbers can be appropriately added to the copolymer latex. Further, the copolymer latex can be appropriately blended with other latexes depending on the purpose of use.
• the copolymer latex of the present invention is preferably blended in a paper coating composition as a paper coating binder.
• the composition for paper coating can be obtained by blending and mixing a copolymer latex and a pigment.
• the pigment examples include inorganic pigments such as kaolin clay, calcium carbonate, talc, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide, and satin white, and organic pigments such as polystyrene latex.
• inorganic pigments such as kaolin clay, calcium carbonate, talc, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide, and satin white
• organic pigments such as polystyrene latex.
• These pigments can be used alone (only one kind) or in combination of two or more kinds.
• the copolymer latex is, for example, 1 to 20 parts by weight, preferably 2 to 12 parts by weight in terms of solids, based on 100 parts by weight (solids) of the pigment. Part mix. If the ratio of the copolymer latex (solid content) is less than 1 part by weight, the pigment may not be sufficiently adhered. When the ratio of the copolymer latex (solid content) exceeds 20 parts by weight, the opacity and white paper gloss may be lowered.
• modified starch such as starch, oxidized starch, esterified starch, natural binders such as soybean protein, casein, such as polyvinyl alcohol, carboxymethylcellulose, etc.
• water-soluble synthetic binders such as synthetic latexes such as polyvinyl acetate latex and acrylic latex can also be blended.
• the paper coating composition may contain other auxiliary agents, for example, dispersants (sodium pyrophosphate, sodium polyacrylate, sodium hexametaphosphate, etc.) and antifoaming agents (polyglycols, fatty acid esters, Phosphate ester, silicone oil, etc.), leveling agents (funnel oil, dicyandiamide, urea, etc.), preservatives, mold release agents (calcium stearate, paraffin emulsion, etc.), fluorescent dyes, color water retention agents (sodium alginate, etc.) It can also be blended.
• dispersants sodium pyrophosphate, sodium polyacrylate, sodium hexametaphosphate, etc.
• antifoaming agents polyglycols, fatty acid esters, Phosphate ester, silicone oil, etc.
• leveling agents for example, leveling agents (funnel oil, dicyandiamide, urea, etc.), preservative
• the obtained paper coating composition is applied to a coated paper by a known technique, for example, a coating machine such as an air knife coater, a blade coater, a roll coater, or a bar coater.
• a coating machine such as an air knife coater, a blade coater, a roll coater, or a bar coater.
• the coated paper is prepared by drying the surface of the coated paper coated with the paper coating composition and finishing it by calendering or the like.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added over 3.5 hours to continue the polymerization.
• the polymerization was terminated when the polymerization conversion rate exceeded 98%.
• Example 2 A pressure-resistant polymerization reactor was charged with 158 parts of polymerized water, 1.5 parts of sodium alkylbenzene sulfonate, and 0.05 part of sodium hydrogen carbonate, and after sufficient stirring, the first stage monomer shown in Table 1 (1 The stage monomer composition) and other compounds were added and polymerization was started at 67 ° C. and reacted for 4.5 hours.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added over 4.0 hours, and then polymerization was continued at 72 ° C. The polymerization was terminated when the polymerization conversion rate exceeded 98%.
• Example 3 A pressure-resistant polymerization reactor was charged with 175 parts of polymerized water, 1.15 parts of sodium alkylbenzenesulfonate, 0.7 part of sodium alkyldiphenyl ether disulfonate, and 0.02 part of sodium bicarbonate, and after stirring sufficiently, Table 1 The first-stage monomer shown (first-stage monomer composition) and other compounds were added, polymerization was started at 75 ° C., and the reaction was allowed to proceed for 3 hours.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added over 4.5 hours, and the polymerization was continued thereafter. The polymerization was terminated when the polymerization conversion rate exceeded 98%.
• Example 4 A pressure-resistant polymerization reactor was charged with 195 parts of polymerized water, 1.15 parts of sodium alkylbenzene sulfonate, and 0.7 parts of sodium alkyldiphenyl ether disulfonate, and after sufficient stirring, the unit amount of the first stage shown in Table 1 The body (first-stage monomer composition) and other compounds were added and reacted at 43 ° C. for 6 hours.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added in 4 hours, and then polymerization was continued at 60 ° C. The polymerization was terminated when the polymerization conversion rate exceeded 98%.
• Example 5 A pressure-resistant polymerization reactor was charged with 115 parts of polymerized water, 0.85 part of sodium alkylbenzene sulfonate, and 0.10 part of sodium hydrogen carbonate, and after sufficient stirring, the first-stage monomer shown in Table 1 ( The first-stage monomer composition) and other compounds were added and reacted at 65 ° C. for 5 hours.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added in 4 hours, and then polymerization was continued at 70 ° C. The polymerization was terminated when the polymerization conversion rate exceeded 95%.
• Example 6 A pressure-resistant polymerization reactor was charged with 99 parts of polymerized water, 0.25 part of sodium bicarbonate, and 0.65 part of sodium alkylbenzene sulfonate, and after sufficient stirring, the first-stage monomer shown in Table 1 ( The first-stage monomer composition) and other compounds were added and reacted at 65 ° C. for 4 hours.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 1 were continuously added over 4 hours, and then polymerization was continued at 68 ° C. The polymerization was terminated when the polymerization conversion rate exceeded 98%.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 2 were continuously added over 3.5 hours, and the polymerization was continued thereafter. The polymerization was terminated when the polymerization conversion rate exceeded 98%.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 2 were continuously added over 1.0 hour, and the polymerization was continued thereafter. The polymerization was terminated when the polymerization conversion rate exceeded 95%.
• the second-stage monomer (second-stage monomer composition) and other compounds shown in Table 2 were continuously added over 4 hours, and then polymerization was continued at 58 ° C. The polymerization was terminated when the polymerization conversion rate exceeded 97%.
• the latex particles were centrifugally settled by a centrifugal separator to separate into a supernatant layer and a latex particle layer, and the obtained supernatant layer (including a carboxyl group component not bound to the latex particles) was vacuum freeze-dried.
• 0.05 g of this vacuum freeze-dried sample was diluted with 10 ml of 50 mM Na 2 HPO 4 and subjected to GPC measurement under the following conditions.
• composition for Paper Coating According to the formulation shown below, the copolymer latex of each example and each comparative example is blended, and an aqueous sodium hydroxide solution is used. The composition for paper coating was adjusted to pH 9.5. (Formulation formulation of paper coating composition) Formulation Kaolin clay 60 parts Heavy calcium carbonate 40 parts Modified starch 4 parts Copolymer latex 10 parts ... Solid content concentration 64% (2) Evaluation of redispersibility of the paper coating composition Each of the obtained paper coating compositions was coated on a NBR black rubber plate with a # 6 wire bar and dried in a 60 ° C hot air circulating oven for 3 minutes. Then, it was washed with running water at 30 ° C. for 1 minute.
• Coated Paper A coating paper (basis weight 67 g / m 2 ) is coated with the above paper coating composition so that the coating amount per side is 13 g / m 2. Then, after coating using a wire bar and drying, calendering was performed under conditions of a linear pressure of 60 kg / cm and a temperature of 50 ° C. to obtain a coated paper.
• Evaluation of dry pick strength of coated paper Relatively grade 5 (excellent) to grade 1 (inferior) is judged by naked eyes when picking up each coated paper sample at the same time with an RI printer. Was visually evaluated. The results are shown in Table 1 and Table 2 below.
• the paper coating composition using the copolymer latex of each example has good fluidity and redispersibility, and these paper coating compositions were applied. All the coated papers obtained in this way have good dry pick strength.
• the copolymer latex of the present invention is used as a binder such as a paper coating binder.

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• 2012
  • 2012-03-19 WO PCT/JP2012/057053 patent/WO2012133002A1/ja active Application Filing
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  • 2012-03-19 CN CN201280011912.8A patent/CN103534309A/zh active Pending
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