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
  • D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
  • D21H17/43—Carboxyl groups or derivatives thereof
• • 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
• • 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 viscosity of the polymer salts in 2% strength aqueous solution at a temperature of 20 ° C. is 5 to 100 mPas (Brookfield viscometer, 20 revolutions / minute).
• the homopolymers and copolymers are prepared by known processes by polymerizing the monomers, cf. US Pat. No. 2,819,189 and US Pat. No. 2,999,038.
• the monomers or mixtures thereof are polymerized continuously or batchwise with the aid of radical polymerization initiators, preferably in water. If the alkali metal or alkaline earth metal salts of acrylic acid or methacrylic acid are already used in the polymerization of the monomers, the copolymer salt solutions to be used according to the invention are obtained directly.
• Acrylic acid and / or methacrylic acid can be polymerized with the corresponding amides or nitriles in water in the manner of a precipitation polymerization.
• the resulting copolymers can be neutralized directly with alkali or alkaline earth metal hydroxides.
• the homopolymers or copolymers obtained in the precipitation polymerization in water can be isolated, dried and mixed with one or more dry, powdered alkali metal hydroxides or alkaline earth metal hydroxides or oxides. These powdery mixtures can then be easily dissolved in water to give a clear solution.
• the homopolymers or copolymers are neutralized after the polymerization with alkali metal hydroxides or alkaline earth metal hydroxides or alkaline earth metal oxides.
• the sodium and potassium as well as the calcium and magnesium salts of the copolymers mentioned above are of particular importance.
• the alkali salts according to the invention do not include the ammonium salts of the copolymers.
• the polymers contain 91 to 100, preferably 95 to 100% by weight of acrylic acid and / or methacrylic acid and 0 to 9, preferably up to 5% by weight of acrylonitrile, methacrylonitrile, acrylamide or methacrylamide, vinyl acetate, maleic anhydride, diisobutene and optionally acrylic ester or methacrylic acid ester.
• the esters are preferably derived from monohydric, primary alcohols having 1 to 4 carbon atoms.
• the calcium and magnesium salts of homopolymers of acrylic acid and methacrylic acid are of particular importance for the process according to the invention.
• Calcium and magnesium salts and mixtures of alkaline earth and alkali salts of homopolymers of acrylic acid or methacrylic acid and copolymers of acrylic acid and acrylamide, acrylic acid and acrylonitrile, acrylic acid, methacrylic acid and acrylamide, and copolymers of acrylic acid, acrylamide and methacrylamide are preferably used.
• the carboxyl groups of the polymers are at least at least 30% neutralized with alkaline earth ions.
• the degree of neutralization is generally 70 to 100%.
• the mixing ratio of the alkaline earth to alkali salts is preferably 30 to 50 to 70 to 50.
• a 2% aqueous solution of the alkali or alkaline earth metal salts to be used according to the invention has a viscosity (Brookfield 20 / min) of 5 to 100, preferably 10 to 30 mPas at a temperature of 20 ° C.
• the pH of the copolymer salt solution is in the range between 4.0 and 10.0.
• the water-soluble alkali and alkaline earth salts of the polymers in question are applied to the paper in the form of a 1 to 10% strength aqueous solution.
• the paper can be impregnated with the alkali or alkaline earth salt solution of the copolymers, e.g. in a size press, or spray a solution of the copolymer salt onto the paper.
• the absorption of preparation solution depends on the absorbency of the paper used. In relation to the solids, to achieve a good increase in the dry strength of the paper, it is sufficient to impregnate the paper with 1 to 4% by weight of the alkali metal or alkaline earth metal salts of the polymers described.
• the increase in the strength of the paper is immediately after drying the paper under usual conditions, e.g. Temperatures of 80 to 110 ° C, obtained. It is not necessary to age the impregnated paper.
• the alkali metal and alkaline earth metal salts of the polymers to be used according to the invention also use together with the starch solutions and copolymer solutions which are frequently used in practice and which contain 2 to 10% by weight, preferably 2 to 6% by weight, of starch and 1 to 3% by weight of the alkali and alkaline earth metal salts of polymers to be used according to the invention.
• the papers can be made from a variety of fiber materials such as sulfite or sulfate pulp (bleached or unbleached), wood pulp or waste paper.
• the use of the alkaline earth metal salts of polymers of acrylic acid and / or methacrylic acid and the comonomers mentioned under b) as surface application agents for paper leads to an unexpected increase in the dry strength of the paper without the wet strength of the paper being appreciably increased.
• the dry strength properties of the paper which are noticeably improved, are e.g. the tear length, burst pressure, pick resistance, tear resistance and the GMT value.
• the invention is illustrated by the following examples.
• the parts given in the examples are parts by weight, the percentages relate to the weight.
• the indicated viscosities were measured at a temperature of 20 ° C in a Brookfield viscometer at 20 revolutions / minute.
• the dry tear length was determined in accordance with DIN 53 112, sheet 1 and the wet tear length in accordance with DIN 53 112, sheet 2.
• the pick resistance of the paper was determined according to the Dennison wax test.
• a homopolymer of acrylic acid which was obtained by polymerizing acrylic acid in aqueous solution using potassium peroxide disulfate as a catalyst, is neutralized with magnesium hydroxide.
• a 2% aqueous solution of the magnesium salt of the homopolymer is prepared, which has a pH of 5.0.
• a wood-free, unsized offset paper produced on a paper machine with a freeness of 25 ° SR, 14% ash (kaolin) and 2% alum and a weight of 80 g / m 2 is mixed with a 2% aqueous solution of the above-mentioned magnesium salt Impregnated homopolymer of acrylic acid and then dried at a temperature of 100 ° C.
• Table 1 shows the viscosity of the preparation solution, the amount of pure polymer salt applied to the paper, based on the weight of the paper, and some properties of the paper obtained.
• Example 1 The homopolymer of acrylic acid described in Example 1 is neutralized with ammonia instead of magnesium oxide and used as a 2% solution at a pH of 5.0 as an impregnating agent for the offset paper specified in Example 1 (Table 1).
• Example 1 The homopolymer of acrylic acid described in Example 1 is used in non-neutralized form as a 2% aqueous solution at a pH of 2.5 as an impregnating agent for the offset paper specified in Example 1.
• Table 1 shows the properties of the paper obtained, together with those properties of the paper which were measured after treating the paper with water and drying (comparative example 1c).
• a 2% solution this copolymer is applied to a wood-free, unsized offset paper with 1% alum, a freeness of 25 ° SR, 10% ash (kaolin) and a weight of 80 g / m 2 .
• the impregnated paper is dried at a temperature of 100 ° C. Further information on the preparation solution and the properties of the impregnated paper can be found in Table 2.
• the copolymer of 95% acrylic acid and 5% acrylamide described in Example 2 is neutralized with ammonia instead of calcium hydroxide and used as a 2% aqueous solution at a pH of 6.0 as an impregnating agent for the offset paper specified in Example 2 (Table 2).
• the copolymer of 95% acrylic acid and 5% acrylamide given in Example 2 is used without neutralization in the form of a 2% aqueous solution, which has a pH of 2.5, for impregnating paper, which is described in Example 2 .
• the paper was dried at the same temperature as in Example 2.
• the results are shown in Table 2.
• Table 2 gives the values which are obtained when the paper described in Example 2 is impregnated with water and dried at 100.degree.
• the examples and comparative examples show that the polymer salts to be used according to the invention compared to the corresponding ammonium salts or the polyacids lead to a further increase in the dry strength of the paper without undesirably increasing the wet strength of the paper.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Medicinal Preparation (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Developing Agents For Electrophotography (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6061575

Family Applications (1)

Country Status (10)

Cited By (4)

Families Citing this family (12)

Citations (2)

Family Cites Families (3)

• 1979
  • 1979-01-27 DE DE19792903218 patent/DE2903218A1/de not_active Withdrawn
  • 1979-12-18 CA CA000342176A patent/CA1140819A/fr not_active Expired
• 1980
  • 1980-01-03 US US06/109,315 patent/US4294873A/en not_active Expired - Lifetime
  • 1980-01-10 FI FI800072A patent/FI64964C/fi not_active IP Right Cessation
  • 1980-01-22 EP EP80100302A patent/EP0013969B1/fr not_active Expired
  • 1980-01-22 DE DE8080100302T patent/DE3060860D1/de not_active Expired
  • 1980-01-22 AT AT80100302T patent/ATE1591T1/de not_active IP Right Cessation
  • 1980-01-24 AU AU54898/80A patent/AU553980B2/en not_active Ceased
  • 1980-01-25 ES ES1980488034A patent/ES488034A0/es active Granted
  • 1980-01-25 NO NO800183A patent/NO157186C/no unknown
  • 1980-01-28 JP JP787680A patent/JPS55103393A/ja active Pending

Patent Citations (2)

Also Published As

Similar Documents

Legal Events