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
  • D21H5/00—Special paper or cardboard not otherwise provided for
  • D21H5/12—Special paper or cardboard not otherwise provided for characterised by the use of special fibrous materials
  • D21H5/14—Special paper or cardboard not otherwise provided for characterised by the use of special fibrous materials of cellulose fibres only
• • 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
• • 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
  • Y10T428/31899—Addition polymer of hydrocarbon[s] only
• • 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
  • Y10T428/31899—Addition polymer of hydrocarbon[s] only
  • Y10T428/31902—Monoethylenically unsaturated
• • 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

• a pigment coat For example, it is known from EP-PS 51 144 to use finely divided polymer dispersions containing nitrogen-containing monomers in polymerized form as mass and surface sizing agents for paper and for coating or impregnating paper and building materials.
• these coating compositions contain no pigments.
• the polymer dispersions are prepared by a two-stage polymerization, in which in the first stage of polymerization a monomer mixture comprising a nitrogen-containing monomer, e.g.
• these polymer dispersions are good surface sizing agents.
• a paper coating composition which contains 1 to 30 parts by weight, based on the solids content, of an amphoteric copolymer latex per 100 parts by weight of a pigment.
• the copolymer contains 20 to 50% by weight of an aliphatic conjugated diolefin, 0.5 to 5% by weight of an ethylenically unsaturated acidic monomer, for example acrylic acid, methacrylic acid or itaconic acid, 0.5 to 5% by weight of an ethylenically unsaturated amine monomer, for example diethylaminoethyl methacrylate , and 10 to 74% by weight of a monoolefinically unsaturated monomer, for example styrene.
• the latex must not contain more than 1% by weight, based on the copolymer, of an emulsifier and should have a gel point within the pH range from 3.5 to 8.5 and should be gellable during the drying of the paper coated with the coating composition.
• the amount of the coating composition applied to one side of the paper is approximately 16 g / m 2 .
• the pigment coat improves the printability of the paper. This procedure is from. suffered from the outset that, due to the high application quantity of the coating composition, no papers with particularly low basis weights can be produced.
• the disadvantages of surface sizing are the limited production capacity due to the application of the surface sizing agent using the size press.
• the present invention has for its object to provide a method for improving the printability of paper, which can be operated at high machine speeds, so that a direct coupling of the remuneration of the paper with the paper production is possible.
• any uncoated, uncoated or otherwise uncoated base paper can be improved.
• the used Natural paper should have the same color acceptability and a high smoothness.
• Such papers are mainly used for newspapers, magazines and advertising brochures.
• the paper qualities mentioned are printed, for example, using the offset or gravure printing process.
• the coating agent to be used according to the invention is a mixture of the above-mentioned components a) to c).
• Fine-particle pigments are used as component a) of the mixture. These are the pigments commonly used in paper coating, e.g. Calcium carbonate, chalk, kaolin, clay, titanium dioxide, barium sulfate, satin white, talc, aluminum silicate, calcium sulfate, magnesium carbonate.
• the particle size of the pigments is 0.2 to 10 u.m. Calcium carbonate, the particle size of which is 87% below 2 ⁇ m, is preferably used as the pigment.
• Basic, ethylenically unsaturated monomers are, for example, acrylic and methacrylic esters of amino alcohols, e.g. Dimethylaminoethyl acrylate, dimethylaminethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropylacrylate, dimethylaminopropyl methacrylate, dibutylaminopropylacrylate, dibutylaminopropyl methacrylate, dimethylaminoneopentylacrylate, methacrylate amide, methacrylate amide, methacrylate amide, methacrylate amide,
• the quaternary compounds of formula 11 are obtained by reacting the basic monomers of formula I with known quaternizing agents, for example with benzyl chloride, methyl chloride, ethyl chloride, butyl bromide, dimethyl sulfate and diethyl sulfate. In the quaternized form, these monomers lose their basic character.
• the compounds of the formula I can also be used in the form of the salts with inorganic or saturated organic acids in the copolymerization.
• Suitable basic monomers are, for example, N-vinylimidazole, 2-methylvinylimidazole, N-vinylimidazoline, 2-methylvinylimidazoline and the corresponding quaternization products or salts of the basic monomers mentioned.
• the group 2) monomers include acrylic and methacrylic esters derived from monohydric, saturated Cs to Cs alcohols, e.g. n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, neopentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate and the corresponding methacrylic acid esters, e.g.
• n-propyl methacrylate, iso-propyl methacrylate, iso-butyl methacrylate and 2-ethylhexyl methacrylate are preferably used in amounts of 38 to 75% by weight.
• Suitable monomers of group 3 which are optionally used to modify the copolymers, are, for example, ethylenically unsaturated C 3 - to Cs-carboxylic acids, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and maleic acid semiesters.
• This group of monomers also includes vinylsulfonic acid and 2-acrylamidomethylpropanesulfonic acid or water-soluble salts of the carboxylic acids and sulfonic acids mentioned.
• the ethylenically unsaturated carboxylic acids and sulfonic acids can be completely neutralized with sodium hydroxide solution, potassium hydroxide solution, ammonia and / or amines or only partially, for example 5 to 95%.
• a further modification possibility of the copolymers from the monomers of groups 1) and 2) results from the fact that basic compounds which have already been mentioned above can be polymerized in as a monomer of group 3), cf.
• the monomers of groups 1) to 3) are copolymerized in the manner of an emulsion copolymer Rization in an aqueous medium in the presence of degraded cationic starches with a viscosity ⁇ i of 0.04 to 0.50 dl / g.
• Such starches contain quaternized aminoalkyl groups. These strengths are commercially available. If the viscosity of these starches is not already in the specified range, they are subjected to oxidative, thermal, acidolytic or enzymatic degradation to the desired viscosity. Cationized, enzymatically degraded potato starch is preferably used.
• the degree of substitution of the cationic starch is 0.01 to 0.1 mol of nitrogen per mol of glucose unit.
• the relative viscosity of the digested starch solutions is determined in 1% by weight aqueous solutions using a capillary viscometer at 25 ° C. and a pH of 3.5, the relative viscosity being determined from the corrected throughput times for solvents t o and solution ti according to the following equation calculated.
• the conversion to 71i is carried out according to the relationship given above on the basis of the information in “Methods in Carbohydrate Chemistry”, Volume IV, Starch, Academic Press, New York and London, 1964, page 127.
• an aqueous solution which contains 1.5 to 25, preferably 1.7 to 21% by weight of a degraded starch with a viscosity ⁇ i of 0.04 to 0.50 dl / g dissolved .
• Degraded starches with a viscosity in the range of 0.3 to 0.5 dl / g are preferably used when it is desired to produce dispersions with a low solids content.
• the degraded starches with a lower viscosity, ie in the range from 0.04 to about 0.3 dl / g, are preferably used in the production of dispersions with higher solids contents, for example 25 to 40% by weight.
• starches of different viscosities 71i can also be used as protective colloids, but the viscosity of the mixture must be in the specified ⁇ i range from 0.04 to 0.50 dl / g, ie starch mixtures can also be used in this case where the viscosity of a starch is outside the specified range.
• 10 to 56 parts by weight of a monomer mixture of components (1) to (3) are subjected to the copolymerization per 100 parts by weight of such an aqueous starch solution.
• the monomers can be emulsified either in the form of a mixture or separately from one another in the aqueous solution of the degraded starch.
• an emulsifier can be added to the aqueous starch solution.
• the monomers can also first be emulsified in water with the aid of an emulsifier and then added in the form of the emulsion to the aqueous starch solution.
• Products with anionic or cationic character are suitable as emulsifiers.
• Such emulsifiers are, for example, sodium alkyl sulfonate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate or dimethylalkylbenzylammonium chloride.
• anionic emulsifiers for anionic starches and cationic emulsifiers for cationic starches.
• the amount of emulsifier which is optionally used is 0 to 0.3, preferably 0.05 to 0.2% by weight, based on the sum of the monomers (1) to (3) used.
• the emulsion polymerization is preferably carried out in the absence of an emulsifier.
• the copolymerization of the monomers in the aqueous solution of the degraded starch is carried out at temperatures from 40 to 110, preferably 50 to 100 ° C. in the presence of an initiator containing peroxide groups.
• Hydrogen peroxide combinations of hydrogen peroxide with a heavy metal salt, e.g. Iron-II-sulfate or a redox system made of hydrogen peroxide with a suitable reducing agent, such as sodium formaldehyde sulfoxylate, ascorbic acid, sodium disulfite and / or sodium dithionite.
• a redox system of hydrogen peroxide, a reducing agent or a mixture of the reducing agents mentioned and, in addition, a small amount of a heavy metal salt, such as, for example, iron (II) sulfate, are preferably used.
• a heavy metal salt such as, for example, iron (II) sulfate
• Other suitable initiators containing peroxide groups are, for example, organic peroxides, hydroperoxides and peroxydisulfates.
• Suitable compounds of this type are, for example, tert-butyl hydroperoxide, acetylcyclohexylsulfonyl peroxide, sodium peroxydisulfate, potassium peroxydisulfate or ammonium peroxydisulfate.
• the components must be thoroughly mixed during the polymerization.
• the reaction mixture is preferably stirred for the entire duration of the polymerization and any subsequent polymerization, if appropriate, to lower the residual monomer content.
• the polymerization is carried out in the absence of oxygen in an inert gas atmosphere, for example under nitrogen.
• the oxygen is first removed from the aqueous solution of the starch and from the monomers and first 1 to 40% of the monomers to be polymerized are added to the aqueous solution of the starch and the monomers therein are emulsified by stirring the reaction mixture.
• the polymerisation begins, as a rule after a short induction period, by adding an aqueous initiator solution beforehand, simultaneously or subsequently.
• the heat of polymerization which arises at the beginning of the polymerization can be used to heat the reaction mixture.
• the temperature can rise to 90 ° C.
• the copolymerization can also be carried out batchwise or continuously.
• a finely divided, aqueous dispersion is obtained in which the copolymer particles are surrounded by a protective colloid shell based on a degraded starch.
• a measure of the fine particle size of the dispersion is the LD value (light transmission value of the dispersion).
• the LD value is measured by measuring the dispersion in 0.01% by weight aqueous solution in a cuvette with an edge length of 2.5 cm with light of the wavelength 546 nm and comparing it with the permeability of water under the conditions mentioned above .
• the permeability of water is given as 100%. The more finely divided the dispersion, the higher the LD value, which is measured using the method described above.
• the average particle size of the copolymer particles without the protective colloid shell from degraded starch can be determined if the starch shell of the latex particles is virtually completely enzymatically degraded. Possible coagulation of the copolymer dispersion can be prevented by adding a suitable emulsifier. After enzymatic degradation, the particle size of the copolymer dispersion can then be measured using commercially available devices, e.g. with the help of the Nanosizer from Coulter Electronics. The average diameter of the copolymer particles without the protective colloid shell is 75 to 110 nm.
• the aqueous polymer dispersions of component b) are prepared with a composition such that the polymers have a glass transition temperature of 5 to 80, preferably 15 to 60 ° C.
• the concentration of the polymer in the aqueous dispersion is 15 to 55, preferably 20 to 45,% by weight.
• the coating compositions contain, based on the solids of the dispersion, 5 to 70, preferably 8 to 30, parts by weight of component b), based on 100 parts by weight of a finely divided pigment or a mixture of pigments.
• 5 to 30% by weight of the polymer of component b) or a mixture of polymers of component b) are preferably replaced by at least one water-soluble polysaccharide. Suitable water-soluble polysaccharides are water-soluble starches, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose and galactomannans.
• component c) of the coating compositions surface-active substances and / or polymeric dispersants come into consideration, each of which disrupt or prevent the formation of surface sizing by the surface sizing agent b).
• the surface-active substances and the polymeric dispersants improve the wettability of the paper with water.
• Suitable surface-active compounds have an HLB value of at least 10 (for a definition of the HLB value, see WC Griffin, J. Cosmetic Chemist, Volume 5, 311 (1954).
• the surface-active substances in question are, for example, as surfactant classes in the Tensid-Taschenbuch by Dr. Stachel, Carl-Hanser-Verlag, Kunststoff-Vienna, 2nd edition 1981, pages 4 to 10.
• Nonionic, anionic as well as cationic surfactants can be used. Products of this type are produced, for example, by the addition of ethylene oxide and / or alcohols, phenols, amines and fatty acids containing 8 to 22 carbon atoms are of particular interest from this group of compounds are, for example, the adducts of 10 to 50 moles of ethylene oxide with 1 mole of dodecanol, C 9 C 13 alcohols and nonylphenol the anionic surfactants come primarily into consideration as component c) sodium lauryl sulfonate.
• Suitable polymeric dispersant of component c) are for example polymers of ethylenically unsaturated C 3 - to Cs-carboxylic acids having a K-value of 10 measured to 50 (in 1% aqueous solution at 25 * C and pH 8 on the sodium salt of the polymers), polymers of acrylamide, methacrylamide and vinyl pyrrolidone with a K value of 10 to 60, polyvinyl alcohols with a molecular weight of 2,000 to 200,000, lignin sulfonates, phenol-formaldehyde condensation products. Urea-formaldehyde condensation products, melamine-formaldehyde condensation products, sulfonated. aromatic formaldehyde condensation products, polyamidoamines, commercially available polyethyleneimines and polydiallyldimethylaminochlorides with a molecular weight of 2,000 to 200,000.
• polymeric dispersant of component c preference is given to using homopolymers of acrylic acid or methacrylic acid with a K value of 10 to 40 (measured in 1% by weight aqueous solution at 25 ° C. and pH 8 on the sodium salt of the polymers).
• a method of making such Polymers are known, for example, from US Pat. No. 4,301,266.
• copolymers of acrylic acid and / or methacrylic acid with acrylamidomethylpropanesulfonic acids are also used in the preferred embodiment of the process according to the invention.
• Copolymers of this type are known, for example, from US Pat. No. 4,450,013 as dispersants and grinding aids for pigments.
• Preferred copolymers used contain 5 to 60% by weight of copolymerized acrylamidomethylpropanesulfonic acid and have a K value in the range from 12 to 35 (measured using the Na salt in a 1% strength aqueous solution at pH 8).
• copolymers of acrylic acid and methacrylic acid which contain the monomers copolymerized in any ratio and have a K value in the range from 10 to 50, or homopolymers of acrylamido-2-methylpropanesulfonic acid with K values from 10 to 35, as polymeric dispersant of component c) are used.
• the coating compositions to be used according to the invention are obtained by mixing the individual components a) to c).
• the pigments can be introduced into the aqueous cationic polymer dispersion of a paper sizing agent and then at least one of the compounds suitable according to c) can be added, or the procedure can be followed such that an aqueous pigment slurry, the solids concentration of which is first prepared by mixing components a) and c) is, for example, in the range from 40 to 85% by weight and the aqueous pigment slurry thus obtained is then mixed with at least one cationic aqueous polymer dispersion of a paper sizing agent.
• a method of operation is particularly preferred in which aqueous slurries of pigments are used, which are obtained by grinding and dispersing the pigments in the presence of polymers of ethylenically unsaturated C 3 to Cs carboxylic acids with a K value of 10 to 50 (measured in 1% strength) aqueous solution at 25 ° C and pH 8 on the sodium salt of the polymer) are available.
• calcium carbonate or chalk is preferably used as the pigment and polyacrylic acid or a copolymer of acrylic acid and acrylamidomethylpropanesulfonic acid with a K value of 10 to 30 (measured as Na salt as stated above) is used as the polymeric dispersant.
• pigment slurries with a particle size of the dispersed particles of approximately 90% ⁇ 2 ⁇ m.
• Such pigment slurries even in high concentrations, for example at solids contents between 60 and 80% by weight, still have a viscosity such that the slurries are light are to be handled.
• These pigment slurries are then mixed with at least one cationic aqueous polymer dispersion according to b).
• the coating compositions which are then applied to the surface of the paper have a solids content in the range from 5 to 60, preferably 15 to 35% by weight.
• the pH of the coating compositions is in the range from 5 to 10.
• the coating compositions are applied to paper on one or both sides.
• the coating compositions are preferably applied continuously using known devices such as those used in paper coating, e.g. Blade, speed sizer and short dwell coater.
• the paper web is guided through the coating unit at a speed of more than 750 m / min, preferably 1000 to 1400 m / min.
• These high coating speeds make it possible to couple the coating of the paper directly with the paper production and to integrate a coating unit into a paper machine.
• a natural paper is then directly obtained, which can be used, for example, in offset printing and gravure printing and as newsprint.
• the parts given in the examples are parts by weight, the percentages are percentages by weight.
• the relative viscosity was measured in 1% by weight aqueous solutions at 25 ° C. and a pH of 3.5 using a capillary viscometer.
• the intrinsic viscosity was calculated from the relative viscosity using the formula given above.
• the printability properties of the coated papers were assessed on the basis of whiteness, brightness, opacity, bleed through and translucency.
• whiteness was measured in accordance with DIN 53145.
• opacity was determined in accordance with DIN 53146.
• the other criteria were determined using the following methods:
• a 40% cationic polymer dispersion which has an LD value is prepared by copolymerization of 20 parts by weight of a N-vinylimidazole quaternized with dimethyl sulfate, 26 parts of acrylonitrile and 54 parts of n-butyl acrylate out of 84.
• Starch II presented and heated to a temperature of 85 C with stirring.
• Starch I is a degraded, cationic potato starch with an intrinsic viscosity ⁇ i of 0.47 dl / g, a degree of substitution of 0.027 mol nitrogen per mol glycose unit and 0.015 mol COOH groups per mol glycose unit.
• the solids content of the starch is 83%.
• Starch II is a degraded, cationic potato starch with an intrinsic viscosity ⁇ i of 1.16 dl / g with a degree of substitution of 0.07 mole nitrogen per mole glycose unit.
• the solids content of the starch is 83%.
• Anionic copolymer dispersion is prepared by polymerizing in the manner of an emulsion polymerization at 80 ° C. by mixing an emulsion of 66.3 parts of n-butyl acrylate, 14 parts of acrylonitrile, 15 parts of styrene and 4 parts of acrylic acid and, at the same time, an aqueous solution of potassium peroxydisulfate in an aqueous solution Solution of sodium lauryl sulfonate metered and polymerized therein. A 50% anionic polymer dispersion with an LD value of 72 is obtained.
• JP-OS 58/115196 500 parts of a 6.6% aqueous solution of an oxidatively degraded potato starch are placed in a 2-liter flask provided with a stirrer and a reflux condenser.
• the degraded potato starch has an intrinsic viscosity ⁇ i ; of 0.27 dl / g and a degree of substitution of 0.034 moles of carboxyl groups per mole of glucose unit.
• 44 parts of styrene, 71.7 parts of n-butyl acrylate and 21.7 parts of tert-butyl acrylate and 3 parts of potassium peroxydisulfate in 50 parts of water are then added to the template, which has been heated to 80 to 90 ° C.
• An anionic polymer dispersion with a solids content of 25% and an LD value of 90 is obtained.
• aqueous starch solution is prepared separately, which is obtained by dissolving 6.7 kg of a cationic or oxidatively degraded starch in 70 kg of water.
• the cationic starch has an intrinsic viscosity ⁇ i of 1.6 and a degree of substitution of 0.09 moles of nitrogen per mole of glucose unit.
• the oxidatively degraded starch has an intrinsic viscosity of ⁇ i of 0.6 dl / g and a degree of substitution of 0.025 moles of COOH groups per mole of glucose unit.
• the coating compositions are then prepared in each case by adding 33.3 kg, based on the polymer, of the cationic dispersions 1 to 3 and of the comparative dispersions 1 and 2 to the mixture of pigment slurry and soluble starch described above.
• the coating agent is adjusted to a solids content of approx. 25% by weight by adding 150 kg of water in each case.
• a natural gravure paper with a basis weight of 60 g / m 2 is coated on both sides with the coating agents described above in a technical coater by means of a blade applicator at a speed of the paper web of 1000 m / min.
• the application weight is 1 g / m2 and page.
• the coated paper web is dried in each case.
• the table shows the coating compositions used in each case and the properties of the coated papers obtained in each case. It can be seen from this that, according to the invention, a considerable improvement in the printability compared to the comparative dispersions is achieved.

Landscapes

• Paper (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Cable Accessories (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Optical Filters (AREA)
• Adhesives Or Adhesive Processes (AREA)

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Publications (3)

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Cited By (5)

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• 1987
  • 1987-09-15 DE DE19873730887 patent/DE3730887A1/de not_active Withdrawn
• 1988
  • 1988-09-08 CA CA000576783A patent/CA1327146C/fr not_active Expired - Fee Related
  • 1988-09-09 AT AT88114757T patent/ATE82783T1/de not_active IP Right Cessation
  • 1988-09-09 EP EP88114757A patent/EP0307816B1/fr not_active Expired - Lifetime
  • 1988-09-09 DE DE8888114757T patent/DE3876192D1/de not_active Expired - Lifetime
  • 1988-09-09 ES ES198888114757T patent/ES2037165T3/es not_active Expired - Lifetime
  • 1988-09-13 NZ NZ226157A patent/NZ226157A/en unknown
  • 1988-09-13 FI FI884196A patent/FI884196A7/fi not_active Application Discontinuation
  • 1988-09-14 JP JP63228915A patent/JPH0197297A/ja active Pending
  • 1988-09-14 DK DK510788A patent/DK510788A/da not_active Application Discontinuation
  • 1988-09-14 AU AU22201/88A patent/AU603258B2/en not_active Ceased
  • 1988-09-14 NO NO88884078A patent/NO884078L/no unknown
  • 1988-09-15 KR KR1019880011981A patent/KR890005349A/ko not_active Withdrawn
  • 1988-09-15 US US07/244,679 patent/US4908240A/en not_active Expired - Fee Related

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