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
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
  • D21H17/45—Nitrogen-containing groups
  • D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
• • 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
  • 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
  • D21H21/14—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 function or properties in or on the paper
  • D21H21/16—Sizing or water-repelling agents
• • 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
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
• • 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
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/52—Addition to the formed paper by contacting paper with a device carrying the material
  • D21H23/56—Rolls
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/3188—Next to cellulosic
  • Y10T428/31895—Paper or wood
  • Y10T428/31906—Ester, halide or nitrile of addition polymer

Definitions

• the present invention relates to a method for producing a cationic surface sizing agent, a sizing agent obtained by the method, and paper and a paper board coated with the sizing agent.
• Conventional cationic surface sizing agents usually contain styrenes and a monomer having a tertiary amino group (i.e., a cationic monomer) as a main component.
• the sizing agent is an aqueous solution of a copolymer having a tertiary amino group obtained by polymerizing the monomer component, or a copolymer having a quaternary ammonium salt group obtained by quaternizing the tertiary amino group (Patent Documents 1 and 2). These copolymers are prepared by the following method.
• Solution-polymerization using an oil-soluble polymerization catalyst is performed in an organic solvent or a mixed solvent of an organic solvent and water.
• Emulsion-polymerization using a water-soluble polymerization catalyst is performed in a water-based solvent.
• the cationic surface sizing agent obtained by such a method has a good sizing property, but has a problem that it is susceptible to environment of usage, especially influences of water (hardness, pH, etc.) and its stability is insufficient.
• a surfactant is often used as an emulsifier (Patent Documents 3 to 7).
• An emulsion-polymerization product using the surfactant is less susceptible to an impact of environment of usage than the cationic surface sizing agent obtained by the solution-polymerization, and an improvement in stability can be expected, but the improvement effect is not adequate.
• such emulsion-polymerization product is inferior in the effect of imparting a sizing property to the cationic surface sizing agent obtained by the solution-polymerization because of use of a surfactant.
• Patent Documents 8 and 9 a production method in which emulsion-polymerization is performed without using the surfactant is known.
• the cationic surface sizing agent obtained without using the surfactant an aqueous solution of a cationic polymer obtained by solution-polymerization is used as a dispersing agent.
• the cationic surface sizing agent exhibits the stability equal to and the sizing property higher than the sizing agent using the surfactant.
• the cationic surface sizing agent obtained by the emulsion-polymerization is inferior in the effect of imparting a sizing property to the cationic surface sizing agent obtained by the solution-polymerization.
• a method for surface treating paper or a paper board comprising a step of coating the surface of the paper or paper board with the cationic surface sizing agent according to the paragraph (9) or a mixture of this sizing agent and a water-soluble high-molecular compound.
• the effect of enabling to provide a cationic surface sizing agent which has excellent dispersion stability and imparts an excellent sizing property regardless of environment of usage, especially water conditions (hardness, pH, etc.) or paper types (paper, paper board, etc.) to which the sizing agent is applied, is achieved.
• the cationic surface sizing agent becomes less susceptible to the hardness or the pH of water to be used by bringing the copolymer (B) into the form of a quaternary ammonium salt. Further, it is possible to attain a sizing agent having the effect that the surface sizing agent is uniformly dispersed without being agglomerated when it is diluted to a concentration of a coating solution.
• a method for producing a cationic surface sizing agent of the present invention contains a first step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture which contains a monomer having a tertiary amino group (a) in the amount of 15 to 45% by weight, a (meth)acrylic acid ester (b) in the amount of 15 to 85% by weight, and styrenes (c) in the amount of 0 to 70% by weight in the presence of a chain transfer agent, wherein an ester moiety of the (meth)acrylic acid ester (b) is alkyl having 4 to 18 carbon atoms;
• the first step is a step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture including a monomer having a tertiary amino group (a) (hereinafter, sometimes referred to as merely “component a”), a specific (meth)acrylic acid ester (b) (hereinafter, sometimes referred to as merely “component b”) and styrenes (c) (hereinafter, sometimes referred to as merely “component c”) in the specific ratio in the presence of a chain transfer agent.
• a tertiary amino group
• component b a specific (meth)acrylic acid ester
• component c styrenes
• the monomer having a tertiary amino group (component a) used in the production method of the present invention is not particularly limited as long as it is a monomer which has a tertiary amino group in a molecule and can be copolymerized with the (meth)acrylic acid ester (b) and the styrenes (c), respectively described later.
• component a examples include dialkylaminoalkyl (meth)acrylate, dialkylaminoalkyl (meth)acrylamide and the like.
• dialkylaminoalkyl (meth)acrylate examples include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate and the like.
• dialkylaminoalkyl (meth)acrylamide examples include dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, diethylaminopropyl (meth)acrylamide and the like.
• dimethylaminoethyl (meth)acrylate or dimethylaminopropyl (meth)acrylamide is preferable.
• the component a is contained in the monomer mixture forming the copolymer (A) in the proportion of 15 to 45% by weight.
• the proportion of the component a is less than 15% by weight, the hydrophilicity of the copolymer (A) is poor, and the copolymer (A) cannot be uniformly dispersed in water.
• the proportion of the component a is more than 45% by weight, the hydrophobicity of the copolymer (A) is poor to cause the sizing property of the resulting sizing agent to be poor.
• the component a is contained preferably in the proportion of 18 to 40% by weight, and more preferably in the proportion of 20 to 35% by weight.
• the components a may be used singly or may be used in combination of two or more thereof. When the components a are used in combination of two or more thereof, the total content of the combination is adapted to satisfy the above range.
• the specific (meth)acrylic acid ester (component b) used in the production method of the present invention is a (meth)acrylic acid ester, an ester moiety of which is a chainlike alkyl having 4 to 18 carbon atoms, a cyclic alkyl having 4 to 18 carbon atoms, or aryl having 6 to 18 carbon atoms.
• the specific (meth)acrylic acid ester is a (meth)acrylic acid ester, in which R of CH 2 ⁇ CH—COOR or CH 2 ⁇ C(CH 3 )—COOR is an alkyl group having 4 to 18 carbon atoms, a cyclic alkyl group having 4 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.
• component b examples include isobutyl (meth)acrylate, n-butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate and the like.
• isobutyl (meth)acrylate, n-butyl (meth)acrylate, and ethylhexyl (meth)acrylate are preferable.
• the component b is contained in the monomer mixture forming the copolymer (A) in the proportion of 15 to 85% by weight. When the proportion of the component b is less than 15% by weight, the sizing property of the resulting sizing agent is poor. On the other hand, when the proportion of the component b is more than 85% by weight, the hydrophilicity of the copolymer (A) is poor, and the copolymer (A) cannot be uniformly dispersed in water.
• the component b is contained preferably in the proportion of 20 to 80% by weight, and more preferably in the proportion of 40 to 80% by weight.
• the components b may be used singly or may be used in combination of two or more thereof. When the components b are used in combination of two or more thereof, the total content of the combination is adapted to satisfy the above range.
• the styrenes (component c) used in the production method of the present invention is not particularly limited as long as it is a monomer which can be copolymerized with the component a and the component b.
• the component c include styrene, ⁇ -methylstyrene, vinyl toluene, ethyl vinyl toluene, chloromethyl styrene and the like. Among these, styrene, ⁇ -methylstyrene, and vinyl toluene are preferable.
• the component c is contained in the monomer mixture forming the copolymer (A) in the proportion of 0 to 70% by weight.
• the proportion of the component c is more than 70% by weight, the ability of the monomer to be copolymerized in a solution-polymerization is poor.
• an effective component in the surface sizing agent agglomerates to form micrograins which are scattered on the surface of paper and can only non-uniformly cover the paper, and therefore a sizing effect is reduced.
• the component c is contained preferably in the proportion of 0 to 50% by weight, and more preferably in the proportion of 0 to 40% by weight.
• the components c may be used singly or may be used in combination of two or more thereof. When the components c are used in combination of two or more thereof, the total content of the combination is adapted to satisfy the above range.
• the monomer mixture may contain monomers other than the components a, b and c to such an extent that the effect of the present invention is not impaired.
• monomers include compounds having a vinyl group or an allyl group such as short chain alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate and the like; hydroxyl group-containing (meth)acrylates such as hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate and the like; (meth)acrylamide; and acrylonitrile.
• short chain alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate and the like
• hydroxyl group-containing (meth)acrylates such as hydroxyprop
• the copolymer (A) is obtained by solution-polymerizing a monomer mixture containing the above-mentioned components a, b and c in the presence of a chain transfer agent.
• the solution-polymerization of a monomer mixture is not particularly limited. For example, it is performed by a usual radical polymerization.
• a solvent used in solution-polymerization can be appropriately selected according to the composition of the monomer mixture.
• the solvent include isopropyl alcohol, n-butanol, isobutanol, t-butanol, sec-butanol, acetone, methyl ethyl ketone, methyl n-propyl ketone, 3-methyl-2-butanol, diethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diisopropyl ketone, ethyl benzene, toluene and the like.
• isopropyl alcohol, methyl isobutyl ketone, and toluene are preferably used.
• the chain transfer agent is used for controlling a weight average molecular weight of the copolymer (A).
• the chain transfer agent include oil-soluble chain transfer agents (for example, mercaptans such as t-dodecylmercaptan, n-dodecyl mercaptan, n-octyl mercaptan, mercaptopropionic acid dodecyl ester and the like, cumene, carbon tetrachloride, ⁇ -methylstyrene dimer, terpinolene, etc.), and water-soluble chain transfer agents (for example, mercaptoethanol, thioglycolic acid and salt thereof, etc.).
• the chain transfer agent can be appropriately selected according to a solvent or the composition of a monomer mixture. An amount of the chain transfer agent can be appropriately determined so as to obtain the copolymer (A) having a desired weight average molecular weight.
• the polymerization initiator is not particularly limited, and examples thereof include azo-type initiators (e.g., azobismethylbutyronitrile, dimethyl azobis isobutylate, azobisdimethylvaleronitrile, azobisisobutyronitrile, etc.), and peroxide-type polymerization initiators (e.g., hydrogen peroxide, benzoyl persulfate, t-butyl peroxybenzoate, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy-2-ethyhexanoate, cumene hydroperoxide, etc.).
• An amount of the polymerization initiator is not particularly limited, and it can be appropriately determined according to the composition of a monomer mixture.
• a temperature or a time of the polymerization reaction is not particularly limited, and it can be appropriately set according to a solvent, the composition of a monomer mixture and a polymerization initiator to be used.
• the polymerization reaction is usually carried out at a temperature of 80 to 120° C., preferably 85 to 115° C. Further, a reaction time is usually 2 to 6 hours, and preferably 3 to 5 hours.
• the copolymer (A) thus obtained is preferably solubilized in water for subjecting it to a subsequent step.
• the copolymer (A) preferably has an average particle diameter of 50 nm or less, and more preferably an average particle diameter of 30 nm or less.
• the second step is a step of obtaining a copolymer (B) by polymerizing the copolymer (A) and a hydrophobic monomer (d) (hereinafter, sometimes referred to as merely “component d”) under the specific conditions without using a surfactant.
• a copolymer (B) by polymerizing the copolymer (A) and a hydrophobic monomer (d) (hereinafter, sometimes referred to as merely “component d”) under the specific conditions without using a surfactant.
• the hydrophobic monomer (component d) used in the production method of the present invention is not particularly limited as long as it is a monomer which can be copolymerized with the copolymer (A).
• the component d include styrene, 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate and the like.
• the copolymer (A) is used at the proportion of 30 to 70% by weight with respect to the entire components forming the copolymer (B), and the component a is used so as to be 8 to 20% by weight with respect to the entire components forming the copolymer (B).
• a good sizing property and dispersibility can be attained by using the copolymer (A) and the component a to have a specific proportion.
• the copolymer (A) is used at the proportion of 40 to 70% by weight with respect to the entire components forming the copolymer (B), and the component a is used so as to be 8 to 18% by weight with respect to the entire components forming the copolymer (B).
• a polymerization reaction of the copolymer (A) with the component d is performed by using an oxidation-reduction system using a water-soluble free-radical initiator and a heavy metal salt, namely, a redox catalyst without using a surfactant.
• a homopolymer of the component d is hardly synthesized, and a graft copolymer (copolymer (B)) of the copolymer (A) and the component d, which is intended in the present invention, becomes easy to be synthesized.
• a sizing agent having excellent dispersibility and enabling to impart an excellent sizing property can be obtained. Further, since the surfactant is not used, a polymer, which is composed of only the component d dispersed by the surfactant, is hardly synthesized, and since the sizing agent ultimately obtained does not the surfactant, a further improvement in the effect of imparting a sizing property can be expected.
• water-soluble free-radical initiator examples include peroxo compounds, azo compounds, hydrogen peroxide, persulfate and the like, and examples of the heavy metal salt include cerium, manganese, iron (II) and the like. Among these, a combination of hydrogen peroxide and ferrous sulfate is preferable.
• a reaction temperature and a reaction time of the polymerization reaction in the second step are not particularly limited, and it can be appropriately set.
• the polymerization reaction is usually carried out at a temperature of 70 to 90° C., preferably 75 to 90° C. Further, the reaction time is usually 1 to 5 hours, and preferably 2 to 4 hours.
• the third step is a step of obtaining a quaternary ammonium salt of the copolymer (B) by quaternizing a tertiary amino group present in the copolymer (B).
• the proportion of a tertiary amino group quaternized among the tertiary amino groups present in the copolymer (B) is not particularly limited. For example, preferably, 50 mol % or more of the tertiary amino group is quaternized, and more preferably, 60 mol % or more of the tertiary amino group is quaternized.
• the quaternization is usually performed by using a quaternizing agent such as epihalohydrin, for example, epichlorohydrin and epibromohydrin.
• a quaternizing agent such as epihalohydrin, for example, epichlorohydrin and epibromohydrin.
• the quaternary ammonium salt of the copolymer (B) thus obtained preferably has an average particle diameter of 100 nm or more, and more preferably an average particle diameter of 100 to 300 nm.
• the cationic surface sizing agent of the present invention is obtained by undergoing the first step to the third step.
• the cationic surface sizing agent thus obtained has excellent dispersion stability without being affected by environments, especially, hardness or a pH of water, at the time of applying the surface sizing agent to the paper or paper board.
• the cationic surface sizing agent can be uniformly applied onto the surface of paper without being agglomerated. Accordingly, the cationic surface sizing agent of the present invention can impart an excellent sizing property to paper or a paper board.
• the cationic surface sizing agent of the present invention may be used singly, or may be used in combination with a water-soluble high-molecular compound in the case of coating the surface of the paper or paper board.
• the water-soluble high-molecular compound and the cationic surface sizing agent of the present invention are preferably mixed in proportions of 500:1 to 1:1, more preferably 100:1 to 5:1 by weight.
• water-soluble high-molecular compound examples include starches such as starch, enzyme-modified starch, thermochemically modified starch, oxidized starch, esterified starch, etherified starch (e.g., hydroxyethylated starch, etc.), cationated starch and the like; polyvinyl alcohols such as polyvinyl alcohol, completely saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, terminal alkyl-modified polyvinyl alcohol and the like; polyacrylamides such as polyacrylamide, cationic polyacrylamide, anionic polyacrylamide, amphoteric polyacrylamide and the like; and cellulose derivatives such as carboxymethylcellulose, hydroxyethyl cellulose, methyl cellulose and the like.
• starches such as starch, enzyme-modified starch, thermochemically modified starch, oxidized
• the paper or paper board to be coated with the cationic surface sizing agent of the present invention is not particularly limited, and any paper or paperboard can be coated with the cationic surface sizing agent of the present invention.
• the surface of paper or a paper board not containing an internal sizing agent, a neutralized paper having a Stockigt sizing degree of 2 second or less and a pH of paper surface of 6.5 to 8.5, or a neutralized paper board having water absorbency by a two minutes Cobb test of 100 g/m 2 or more and a pH of paper surface of 6.5 to 8.5 is coated with the cationic surface sizing agent of the present invention.
• the cationic surface sizing agent of the present invention can be applied without being affected by hardness or a pH of water, the cationic surface sizing agent is very useful. Moreover, the paper and paper board coated with the cationic surface sizing agent of the present invention has an excellent sizing property and are used in various fields.
• DM Dimethylaminoethyl methacrylate
• DMAPAA Dimethylaminopropyl acrylamide
• 2EHA 2-ethylhexyl acrylate
• 2EHMA 2-ethylhexyl methacrylate
• MMA Methyl methacrylate
• LMA Lauryl methacrylate
• nBA n-butyl acrylate
• nBMA n-butyl methacrylate
• iBA i-butyl acrylate
• iBMA i-butyl methacrylate
• tBMA t-butyl methacrylate
• CHMA Cyclohexyl methacrylate
• 2HEA 2-hydroxyethyl acrylate
• DM dimethylaminoethyl methacrylate
• EHA 2-ethylhexyl acrylate
• St styrene
• n-dodecyl mercaptan 0.7 parts by weight
• toluene 32 parts by weight
• DM dimethylaminoethyl methacrylate
• nBMA n-butyl methacrylate
• St styrene
• t-dodecyl mercaptan 0.5 parts by weight
• isopropyl alcohol 32 parts by weight
• Copolymers (A3) to (A8) were obtained by following the same procedure as in Synthesis Example A2 except for using the components illustrated in Table 1 in the proportions illustrated in Table 1, respectively.
• DM neutralization percentage described in the following table illustrates how much the tertiary amino group moiety of the obtained copolymer and the traces of remaining DM are neutralized. For example, when the DM neutralization percentage is 100 mol %, it means that these are completely neutralized.
• DM dimethylaminoethyl methacrylate
• St styrene
• n-dodecyl mercaptan 1.5 parts by weight
• isopropyl alcohol 32 parts by weight
• the mixture was heated to about 85° C., and 2,2′-azobisisobutyronitrile (1.5 parts by weight) was added as an initiator, and the resulting mixture was reacted at about 90° C. for 3 hours.
• Copolymers (A10) to (A18) were obtained by following the same procedure as in Synthesis Example A9 except for using the components illustrated in Table 1 in the proportions illustrated in Table 1, respectively.
• DM neutralization Component a Component c percentage Average (parts by Component b (parts by (90% acetic acid particle Copolymer weight) (parts by weight) weight) (parts by weight) diameter (A) Synthesis DM 2EHA St 100 mol % 30 nm or less A1 Example (20) (20) (60) (8.5) A1 Synthesis DM nBMA St 100 mol % 30 nm or less A2 Example (30) (30) (40) (12.7) A2 Synthesis DM tBMA St 100 mol % 30 nm or less A3 Example (40) (40) (20) (17.0) A3 Synthesis DM nBMA St 100 mol % 30 nm or less A4 Example (20) (40) (40) (8.5) A4 Synthesis DMAPAA iBMA 2EHMA St 100 mol % 30 nm or less A5 Example (25) (30) (20) (25) (10.6) A5 Synthesis DMAPAA nBMA 2EHA St 100
• aqueous solution of ferrous sulfate (2.2 parts by weight) (concentration 1% by weight) and an aqueous solution of ascorbic acid (1.8 parts by weight) (concentration 1% by weight) were added, and methyl methacrylate (MMA) (11 parts by weight), n-butyl methacrylate (nBMA) (6 parts by weight), 2-ethylhexyl acrylate (2EHA) (6 parts by weight), styrene (St) (20 parts by weight) as hydrophobic monomers, and hydrogen peroxide solution (16 parts by weight) (concentration 8% by weight) were charged into a four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours.
• MMA methyl methacrylate
• nBMA n-butyl methacrylate
• EHA 2-ethylhexyl acrylate
• St styrene
• epichlorohydrin (7.1 parts by weight) was added to contents of the four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours and diluted with water so that a solid concentration was 30% by weight to obtain a sizing agent.
• nBMA n-butyl methacrylate
• nBA n-butyl acrylate
• St styrene
• epichlorohydrin (21.4 parts by weight) was added to contents of the four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours, and diluted with water so that a solid concentration was 30% by weight to obtain a sizing agent.
• Sizing agents were obtained by following the same procedure as in Example 1 except for using the components illustrated in Table 2 in the proportions illustrated in Table 2, respectively.
• the polymerization initiators illustrated the following table are as follows.
• I1 Hydrogen peroxide solution (concentration 8% by weight)
• I2 Aqueous solution of ferrous sulfate (concentration 1% by weight)
• I3 Aqueous solution of ascorbic acid (concentration 1% by weight)
• I4 2,2′-azobis(2-methylpropiondiamine)dihydrochloride
• Example 1 A1 25 100 mol % — MMA nBMA 2EHA St (400) (7.9) (11) (6) (6) (20)
• Example 2 A2 150 — — nBMA nBA — St (400) (36) (32) (32)
• Example 3 A3 400 — — iBMA CHMA LMA — (400) (67) (100) (67)
• Example 4 A4 50 50 mol % — tBMA 2EHA nBA St (400) (7.9) (22) (14) (12) (6)
• Example 5 A5 100 — — MMA iBMA LMA St (400) (20) (20) (20) (21)
• Example 6 200 — — iBA LMA — St (400) (31) (31) (60)
• Example 7 A7 150 — — nB
• aqueous solution of ferrous sulfate (7.9 parts by weight) (concentration 1% by weight) and an aqueous solution of ascorbic acid (6.2 parts by weight) (concentration 1% by weight) were added, and methyl methacrylate (MMA) (40 parts by weight) as a hydrophobic monomer, n-butyl methacrylate (nBMA) (70 parts by weight) and 2-ethylhexyl methacrylate (2EHMA) (40 parts by weight) as hydrophobic monomers, and hydrogen peroxide solution (56 parts by weight) (concentration 8% by weight) were charged into a four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours. After the reaction, the reactant was cooled and diluted with water so that a solid concentration was 30% by weight to obtain a sizing agent.
• MMA methyl methacrylate
• nBMA n-butyl methacrylate
• 2EHMA
• aqueous solution of ferrous sulfate (2.8 parts by weight) (concentration 1% by weight) was added, and methyl methacrylate (MMA) (18 parts by weight), n-butyl methacrylate (nBMA) (17 parts by weight) and n-butyl acrylate (nBA) (18 parts by weight) as hydrophobic monomers, and hydrogen peroxide solution (20 parts by weight) (concentration 8% by weight) were charged into a four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours.
• MMA methyl methacrylate
• nBMA n-butyl methacrylate
• nBA n-butyl acrylate
• epichlorohydrin (8.9 parts by weight) was added to contents of the four-necked flask, and the resulting mixture was reacted at about 85° C. for 3 hours, and diluted with water so that a solid concentration was 30% by weight to obtain a sizing agent.
• Sizing agents were obtained by following the same procedure as in Comparative Example 2 except for using the components illustrated in Table 3 in the proportions illustrated in Table 3, respectively.
• DM dimethylaminoethyl methacrylate
• EHMA 2-ethylhexyl methacrylate
• St styrene
• n-dodecyl mercaptan 1.5 parts by weight
• isopropyl alcohol 32 parts by weight
• the mixture was heated to about 85° C., and 2,2′-azobisisobutyronitrile (1.5 parts by weight) was added as an initiator, and the resulting mixture was reacted at about 90° C. for 3 hours.
• a neutralization percentage of the tertiary amino group moiety of the copolymer and the traces of remaining DM was 100 mol %, and a quaternization percentage of the obtained sizing agent (copolymer) was 80 mol %, and an average particle diameter of the sizing agent was 30 nm or less.
• a sizing property (Stockigt sizing degree and water absorbency by a two minutes Cobb test) and a foaming property of the sizing agents obtained in Examples and Comparative Examples were evaluated according to the following method. The results of evaluations are illustrated in Table 4.
• Each of the sizing agents obtained in examples and comparative examples, oxidized starch, and tap water having hardness of 60 ppm (in terms of CaCO 3 ) were mixed so as to be 0.4% by weight, 5.0% by weight, and 94.6% by weight, respectively, to prepare a coating solution.
• the obtained coating solution was applied onto both surfaces of a neutralized high-quality base paper (basis weight 70 g/m 2 , Stockigt sizing degree 0 second, pH of paper surface 7.6) not having an internal sizing agent added in such a way that the amounts of the solution absorbed at both surfaces was 30 g/m 2 .
• the coating solution was dried at 90° C. for 90 seconds using a rotary drum dryer (manufactured by KUMAGAI RIKI KOGYO CO., LTD., KRK rotary dryer) to obtain a coated paper.
• the Stockigt sizing degree of each coated paper obtained was measured according to JIS P 8122.
• Each of the sizing agents obtained in examples and comparative examples, and tap water having hardness of 60 ppm (in terms of CaCO 3 ) were mixed so as to be 0.2% by weight and 99.8% by weight, respectively, to prepare a coating solution.
• the obtained coating solution was applied onto one surface of a base paper for a liner (basis weight 180 g/m 2 , water absorbency by a two minutes Cobb test 210 g/m 2 , pH of paper surface 7.2) having an internal sizing agent added in such a way that the amount of the solution absorbed at one surface was 15 g/m 2 .
• the coating solution was dried at 90° C. for 90 seconds using the above-mentioned rotary drum dryer to obtain a coated paper.
• the water absorbency by a two minutes Cobb test of each coated paper obtained was measured according to JIS P 8140.
• the coating solution and the coating solution with high hardness used in the evaluation of the Stockigt sizing degree were put in a mixer for domestic use (manufactured by Panasonic Corporation, a fiber mixer), and stirred for 3 minutes. A height of a foam was measured after a lapse of three minutes from a stop of stirring.
• the case where the amount of a residue is smaller shows that the amount of an agglomerated substance is smaller, and the sizing agent has excellent dispersion stability.
• the paper coated with the cationic surface sizing agent prepared by the production method of the present invention is found to have an excellent sizing property which compares favorably with the case using tap water even when using the synthesized hard water, and to have low water absorbency by a two minutes Cobb test to hardly absorb water.
• the cationic surface sizing agent prepared by the production method of the present invention exhibits a low foaming property in any of use of tap water and use of synthesized hard water, and the sizing agent is excellent in the workability of coating.
• the amount of a residue in filtration is small even when any of tap water and synthesized hard water is used, and stability (dispersion stability) in the coating solution is excellent.
• the paper coated with the cationic surface sizing agent prepared by the method other than the production method of the present invention is found to have relatively a low sizing degree. Further, it is found that even when this paper has a relatively good sizing property (Comparative Examples 2 and 7), the sizing degree is reduced to about one-half in the case of using synthesized hard water. Further, it is found that this paper has relatively high water absorbency by a two minutes Cobb test and extremely tends to absorb water particularly when synthesized hard water is used. Furthermore, this surface sizing agent is found to extremely tend to foam when synthesized hard water is used. Further, it is found that the amount of a residue in filtration is large in any of use of tap water and use of synthesized hard water, and stability (dispersion stability) in the coating solution is low.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=46929856

Family Applications (1)

Country Status (4)

Cited By (2)

Families Citing this family (4)

Citations (5)

Family Cites Families (5)

• 2011
  • 2011-03-29 JP JP2011071459A patent/JP5879042B2/ja active Active
  • 2011-08-18 US US14/007,902 patent/US20140023872A1/en not_active Abandoned
  • 2011-08-18 WO PCT/JP2011/068672 patent/WO2012132045A1/ja active Application Filing
  • 2011-08-18 CN CN2011800696262A patent/CN103459717A/zh active Pending

Patent Citations (5)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events