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
  • D21H17/03—Non-macromolecular organic compounds
  • D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
  • D21H17/07—Nitrogen-containing compounds

Definitions

• the present invention relates to a process for the production of paper or cardboard which is sized in alkaline or neutral size and which consists in adding an anionic, hydrophobic sizing agent and a cationic retention agent to the pulp suspension having a pH of at least 6.5, wherein the sizing agent, for example an N, N-dialkylamide group preferably having 6 to 22 carbon atoms and at least one acidic group, e.g. contains a carboxyl group.
• the sizing agent for example an N, N-dialkylamide group preferably having 6 to 22 carbon atoms and at least one acidic group, e.g. contains a carboxyl group.
• the pH of the fiber suspension is at least 6.5 in the absence of acids, e.g. Sulfuric or formic acid, or especially from e.g. latent acidic sulfates, e.g. Aluminum sulfate (alum) is discontinued.
• acids e.g. Sulfuric or formic acid
• latent acidic sulfates e.g. Aluminum sulfate (alum) is discontinued.
• paper with relatively little sizing agent is obtained which has an increased shelf life
• the subject of the present invention thus relates to a process for the alkaline or neutral gluing of paper or cardboard, that is to say a process for the production of alkaline or neutral glued paper or cardboard, which is characterized in that aqueous, cellulose-containing, optionally filler-containing fiber suspensions are used in the absence of acids or latently acidic sulfates such as aluminum sulfate have a pH of at least 6.5, preferably at least 7.0, at least (A) an anhydride group-free sizing agent which has a single N, N-dialkyl or N, N-dialkenylamide group, each having at least 6 carbon atoms in the alkyl or alkenyl radical, as hydrophobic substituents and at least one anionic salt form or acidic, ie has a free group and (B) adds a polymeric, cationic retention agent in any order or simultaneously.
• aqueous, cellulose-containing, optionally filler-containing fiber suspensions are used in the absence
• the specified sizing agents (A) are new compounds which, together with the process for their preparation, also form further objects of the present invention.
• the sizing agents (A) used according to the invention generally have 1, 2 or 3 anionic groups, which are generally present as acidic carboxyl, hydroxyl or sulfo groups, sulfo groups and especially carboxyl groups being preferred. Sizing agents which have two or especially only one such anionic group are preferred. Such groups are preferably in the form of salts, for example amine, ammonium or Sodium salts in aqueous medium at a pH of at least 6.5, preferably at least 7.0, of the fiber suspensions and can optionally form anions during paper manufacture.
• the cationic retention agents (B) can also form cations.
• anion-active or cation-active retention agents The ability of the sizing agents and the retention aids to form anions or cations under the conditions of papermaking can also be described as anion-active or cation-active.
• anionic sizing agents and the cationic retention agents can also be called anion-active sizing agents or cation-active retention agents.
• the sizing agents (A) have a single N, N-dialkyl or N, N-dialkenylamide group as hydrophobic substituents.
• the two alkyl or alkenyl radicals in these N, N-dialkyl or N, N-dialkenyl groups each independently have at least 6, especially 6 to 22, preferably 11 to 22, in particular 16 to 20 carbon atoms.
• Alkyl residues are preferred over alkenyl residues.
• the hydrophobic substituents are generally derived from unsaturated or, above all, saturated, secondary fatty amines.
• symmetrical, secondary amines in which the two alkenyl or alkyl radicals are identical are preferred over the asymmetrical, secondary amines with two different alkyl or alkenyl radicals.
• the fatty amines in turn are derived from unsaturated or, above all, saturated C 6 -C 22 , preferably C 11 -C 22 , in particular C 16 -C 20 fatty acids.
• These are, for example, capronic, preferably caprylic, capric, lauric, myristic or myristoleic, palmitoleic, elaeostearic, clupanodonic acid, in particular oleic, elaidic, erucic, linoleic and linolenic acid.
• palmitic, stearic, oleic and behenic acid is of particular importance, with palmitic and especially stearic acid being the focus of interest. Easily accessible, technical mixtures of these fatty acids are also suitable.
• Synthetic fatty acids that can be produced, for example, by oxosynthesis are also included in the definition given.
• symmetrical, secondary amines from which the N, N-dialkyl or N, N-dialkenylamide groups of the sizing agents used according to the invention are derived e.g. Dihexylamine, dioctylamine (also called dicaprylamine) and especially didodecyl, dihexadecyl and dioctadecenylamine (also called dilauryl, dipalmityl and dioleylamine) mentioned.
• dioctadecylamine (also called distearylamine) is of particular importance.
• ARMEEN O 2 HT which is a technical amine mixture with an average molecular weight of 500, contains distearylamine as the main component alongside other symmetrical and asymmetrical secondary amines as secondary components, these secondary components having, for example, oleyl, lauryl and palmityl residues of interest.
• Symmetrical and asymmetrical, secondary amines of the type indicated can be obtained from the corresponding fatty acids mentioned above by methods known per se, for example by the fatty acid being e.g. with ammonia to form the nitrile as an intermediate and then by catalytic hydrogenation to the secondary amine.
• Aliphatic, cycloaliphatic or aromatic sizing agents of the formula (1) in which A 1 is a sulfo or especially carboxyl group and A z and A 3 are a hydroxyl or carboxyl group and in which the 2 alkyl or alkenyl radicals of the hydrophobic amide group are identical, are further preferred and correspond accordingly to the formula wherein A 4 is a sulfo or carboxyl group, A 5 and A 6 independently of one another each have a hydroxyl or carboxyl group which are present in salt form as anionic groups or as acidic, ie free, groups, D z naphthylene, phenylene, di- or tetrahydrophenylene, cyclohexylene, Norbornenylene, Hexachlornorbornenylen, C 2 -C 4 alkenyls or C 2 -C 6 alkylene mean and R 1 , n and m have the meanings given.
• phenylene is preferred over the other definitions of D 2 and a carboxyl group over a sulfo group as the definition of A 4 .
• m is preferably 1
• n is both 1 and 2
• a 5 is preferably a carboxyl group.
• C 2 -C 4 alkenylene is Dz
• n and m are preferably 1.
• both n and m are preferably 2, provided that C 2 -C 6 alkylene is D 2 , where A 5 and A 6 are preferably from one another are different.
• the two alkyl or Alkenyl residues of the hydrophobic amide group preferably have 16 to 22 carbon atoms.
• any compounds present in salt form are of primary interest, those of the formula correspond in which D 3 is a bivalent radical of the formula which is optionally present in salt form or or a divalent radical of the formula or and R 3 is alkyl or alkenyl having 16 to 20 carbon atoms and n is 1 or 2.
• the sizing agents of the formulas (5), (6), (10) and (11) are mixtures of isomers. Before they are used as component (A) in the paper sizing process according to the invention, the sizing agents generally do not need Recrystallization to be cleaned, but can usually as such, as they arise in their manufacture, i.e. can be used without further processing.
• the sizing agent (A) and the retention agent (B) are added separately (in any order) to the fiber suspension in the process according to the invention for sizing paper or cardboard, it is expedient to use the sizing agent at least partially in salt form.
• such salts can be obtained by adding the sizing agents (A) after production by adding, inter alia, an alkylamine or alkanolamine with a total of at most 6 carbon atoms, for example trimethylamine, triethylamine, monoethanolamine, diethanolamine, especially by adding ammonia or an alkali metal hydroxide , for example potassium or especially sodium hydroxide, as a rule completely or partially converted into the corresponding salts in an aqueous medium at room temperature (about 15 to about 25 ° C.).
• An alkali metal hydroxide for example potassium or especially sodium hydroxide or in particular ammonia, is expediently generally used in the form of its dilute, about 1 to 10 percent by weight, aqueous solutions.
• a maximum of 3 mol, especially 0.1 to 1.5, in particular 0.9 to 1.1 mol, of ammonia or alkali metal hydroxide is expediently used per acidic group of the sizing agent present.
• the sizing agents present as salts thus have, for example, acidic carboxyl, hydroxyl or sulfo groups which are at least partially converted into the groups -COO M, -O ⁇ M ⁇ or SO 3 ⁇ M ⁇ , where M ? means the corresponding amine, ammonium or alkali metal cations.
• Preferred sizing agents (A) of the stated type have molecular weights of approximately 250 to approximately 1000, preferably approximately 500 to approximately 750 and, owing to their content of at least one acidic group of the specified type, an acid number (mg KOH / g substance) of approximately 55 to approximately 320 , preferably about 70 to about 180.
• the sizing agents used as component (A) in the paper sizing process according to the invention are compounds which are known per se and those which are new per se, which are prepared by methods known per se.
• US Pat. No. 4,402,708 discloses the compound of formula (4) which, however, is used as an additive for mineral oils.
• US Pat. No. 4,402,708 contains no information about analogous compounds with two carboxyl groups, ie about compounds of the formula (3) in which D 3 represents the rest of the formula (3.1) and n in formula (3.1) 2 and in particular via compounds of the formula (5).
• US Pat. No. 4,034,040 discloses compounds of the formula (3) in which D 3 is lower alkylene, preferably having at most 4 carbon atoms, and in particular the compounds of the formulas (6) and (7), but which are used as agents for combating viral infections .
• German Offenlegungsschrift 2,459,165 discussed at the outset discloses compounds of the formula (9), but does not provide any information about the compounds of the formulas (10) and (11).
• the compounds per se are new, which may be in salt form and, inter alia, of the formula correspond in which D 4 for a divalent radical of the formula which is optionally present in salt form or of the formula (3.2) or represents a divalent radical of the formula (3.6) or (3.7) and R 1 and R 2 are different from one another or preferably the same and in each case mean alkyl or alkenyl having 6 to 22 carbon atoms, the process relating to them Production characterized in that a secondary, asymmetrical or preferably symmetrical amine of the formula
• R i and R 2 are different from one another or preferably identical and each represent alkyl or alkenyl having 6 to 22 carbon atoms, as a rule with trimellitic anhydride, citric acid, itaconic anhydride or citraconic anhydride in approximately equimolar amounts.
• a polymeric, cationic retention agent (B) is always used, which generally has a molecular weight of at least about 1000, preferably about 2000 to about 2,000,000 having. Retention agents with molecular weights in the range of 10,000 to 100,000 are particularly preferred. In principle, any commercially available retention agent can be used in the process according to the invention.
• Examples of conventional retention agents (B) which are particularly suitable for use together with the sizing agent (A) in the paper sizing process according to the invention are polyalkyleneimines; Epihalohydrin adducts of reaction products of polyalkylene polyamines and aliphatic dicarboxylic acids; Epihalohydrin adducts of reaction products of polyalkylene polyamines, dicyandiamide and optionally unesterified or esterified with alkanols, organic dicarboxylic acids; Reaction products of dicyandiamide, formaldehyde, ammonium salts of strong inorganic acids and alkylenediamines or polyalkylene polyamines; cationically modified starches or carbohydrates from carob or guar gum; Copolymers based on polyamide amines and reaction products of epihalohydrins and polymerized diallylamines mentioned.
• epichlorohydrin adducts of reaction products from polyalkylene polyamines and aliphatic dicarboxylic acids are described, for example, in British patent specification 865 727, epichlorohydrin adducts from reaction products consisting of dicyandiamide and diethylenetriamine or triethylene tetramine, for example in German Offenlegungsschrift 2,710,061 and 486, Epin.
• Preferred cationically modified starches or carbohydrates from locust bean or guar gum are, for example, alkylene oxide adducts of these starches or carbohydrates, the alkylene oxide used having 2 or 3 carbon atoms in the alkylene radical and quaternary ammonium groups or, in particular, representing, for example, a trimethylglycidylammonium halide.
• Copolymers based on polyamide amines have molecular weights of 10 3 to 10 5 , preferably 10 3 to 10 "and are made, for example, of aliphatic, saturated dicarboxylic acids with 2 to 10, preferably 3 to 6 carbon atoms, in particular adipic acid, and polyalkylene polyamines, for example polypropylene - And polyethylene polyamines, in particular dimethylaminohydroxypropyl-diethylenetriamine, are available and are described, for example, in the CTFA Cosmetic Ingredient Dictionary, 3rd edition 1982, of the Cosmetic Toiletry and Fragrance Association.
• Reaction products from epihalohydrins and polymerized diallylamines preferably have molecular weights of 1000 to 2000 and are, for example in U.S. Patent Nos. 3,700,623 and 4,279,794.
• retention agents (B) which are in the foreground of interest for use together with the sizing agents (A) in the paper sizing process according to the invention, is a maize or potato starch modified with a propylene oxide containing quaternary ammonium groups, the 25% strength of which is suspended in distilled water at 20 ° C has a pH of 4.2 to 4.6, a polyethyleneimine which has a molecular weight of 10,000 to 100,000, an epichlorohydrin adduct of a reaction product of triethylene tetramine and dicyandiamide, an epichlorohydrin adduct of a reaction product of diethylene triamine , Dicyandiamide and dimethyl adipate, a reaction product of dicyandiamide, formaldehyde, ammonium chloride and Ethylene diamine, an epichlorohydrin adduct of a poly-N-methyldiallylamine and a copolymer of adipic acid and dimethylaminohydroxy
• the mass sizing of paper or cardboard is generally 0.02 to 3, preferably 0.05 to 3, in particular 0.1 to 0.8 percent by weight of the sizing agent (A) and 0.02 to 3, preferably 0.05 to 3, in particular 0.1 to 0.4 percent by weight of the retention agent (B), based in each case on dry matter at (A) and (B) and on the solids content of the fiber suspension.
• sizing agent (A) and the retention agent (B) are sufficient only for the so-called “size press control", which cannot be determined using conventional sizing tests (see, for example, the article “Control and Understanding of Size Press Pickup “by DR Dill in the journal TAPPI (Proceedings of the Technical Association of the Pulp and Paper Industry, Volume 57, No. 1 of January 1974, pages 97-100).
• the fibrous suspension to which the sizing agents (A) and the Retention agents (B) are given generally has a solids content of 0.1 to 5, preferably 0.3 to 3, in particular 0.3 to 1 percent by weight and a Schopper-Riegler freeness of about 10 ° to about 60 °, above all 20 to 60 °, preferably 20 to 45 °, in particular 25 to 35 °, It generally contains cellulose, in particular those made of softwood, for example pine wood, or of hardwood, ie hardwood, for example beech wood, which is produced by conventional methods , for example the sulfite or especially the sulfate driving is established.
• the fiber suspension may contain groundwood. Waste paper can also be contained in the fiber suspension.
• pulp suspensions made according to the so-called CMP or CTMP process can be considered.
• the fiber suspension can also contain organic or mineral fillers.
• Organic fillers include synthetic pigments, e.g. Polycondensation products made from urea or melamine and formaldehyde with large specific surfaces, which are in highly dispersed form and e.g. in British patents 1,043,937 and 1,318,244 are described as mineral fillers, among others, titanium dioxide, calcium sulfate and especially talc and / or chalk (calcium carbonate).
• the fibrous suspension contains 0 to 40, preferably 5 to 25, in particular 15 to 20 percent by weight, based on the solids content of the fibrous suspension, of dry matter of the fillers of the type specified.
• Fibrous suspensions containing no filler can be used in a wide pH range, e.g. 6.5 to 10.0, especially 7 to 10 are present. Fiber suspensions are preferred which, if appropriate by adding talc, especially calcium carbonate, especially chalk, have a pH of about 7 to about 9.
• the fibrous suspension can also contain additives such as e.g. Starch or its degradation products that increase fiber / fiber or fiber / filler bonding.
• High molecular weight polymers of the acrylic acid series e.g. Polyacrylamides with molecular weights of more than 1,000,000 can be added to the fiber suspension as an aid to retain the finest pulp fiber particles, with minimal amounts of about 0.005 to 0.02 percent by weight, based on the dry matter of the polymer and the solids content of the fiber suspensions, being sufficient.
• the fibrous suspension is processed further in a manner known per se on sheet formers or, preferably, continuously on paper machines of conventional design to give paper or cardboard. After drying at about 100 to 140 ° C. for about 0.5 to 10 minutes, papers with a variable basis weight of, for example, 50 to 200 g / m 2 are obtained.
• the aqueous composition for carrying out the paper sizing process according to the invention contains, in addition to optional customary additives, the sizing agent (A), provided that the sizing agent and the retention agent (B) are added separately to the fiber suspension.
• the preparation generally contains the sizing agent in whole or in part in the form of its salts (obtained using, for example, ammonia, an alkyl or alkanolamine or an alkali metal hydroxide of the type specified in the ratios given above).
• such compositions contain 5 to 30, preferably 5 to 20 percent by weight of dry matter of the sizing agent, which is at least partially in salt form, based on the weight of the aqueous composition.
• aqueous compositions of the type mentioned optionally contain, as conventional additives, surface-active compounds, for example dispersants or further emulsifiers and / or water-soluble organic solvents.
• Dispersants and emulsifiers include, for example, conventional lignin sulfonates, lignin carboxylates, carboxymethyl cellulose, ethylene oxide adducts of alkylphenols, fatty amines, fatty alcohols or fatty acids, fatty acid esters of polyhydric alcohols, substituted benzimidazoles or condensation products of formaldehyde and aromatic sulfonic acids, especially naphthalene sulfone acids.
• anionic surfactants in particular sulfate surfactants, for example diethanolamine lauryl sulfate, sodium lauryl sulfate or ethoxylated lauryl sulfates.
• Possible water-soluble, organic solvents are aliphatic ethers with 1 to 10 carbon atoms, for example dioxane, ethylene glycol n-butyl ether or diethylene glycol monobutyl ether or alcohols with 1 to 4 carbon atoms, for example isopropanol, ethanol or methanol.
• the quantitative ratio (component (A)): (additives) in the composition is 1: 0.02 to 1: 0.3, preferably 1: 0.05 to 1: 0.1 , based on the dry matter of the sizing agents and additives.
• compositions are prepared in a conventional manner by combining the sizing agent (A) together with the retention agent (B) or the sizing agent (A), usually partly in the form of its salt alone, either in the molten state or preferably in the solid state, in particular in powdered form, usually in the presence of glass beads and, if necessary, emulsifiers (in the case of sizing agents in the molten state) or dispersants (in the case of sizing agents in powder form) at a maximum of 90 ° C, preferably about 50 to 85 ° C for emulsions, in particular about 15 up to about 25 ° C.
• dispersions with storage-stable, homogeneous, further dilutable emulsions or preferably dispersions being obtained.
• the sizing agents together with the retention aids or the sizing agents which are present entirely or at least partially as salts are generally self-dispersing or self-emulsifying, the use of dispersants or emulsifiers is generally not absolutely necessary. This also applies to the optional addition of solvents and / or surfactants, which are only used if the dispersions or emulsions have insufficient storage stability.
• a process for producing paper with a glued surface in which a glue liquor which contains components (A) and (B), for example by spraying, preferably by padding, usually applied to the paper at room temperature (15-25 ° C.) and then the impregnated paper at 60 to 140 ° C., preferably 90 to 110 ° C. for 0.1 to 10, preferably 2 is dried to 6 minutes. After drying, a paper is obtained which has a surface application of sizing and retention agent of 50 to 150, preferably 60 to 120 mg / m 2 .
• the paper to be glued is any type of paper with any basis weight, for example paper and cardboard made from bleached or unbleached sulfite or sulfate cellulose.
• the glue liquor required for this is prepared by diluting with water the emulsions or dispersions specified above which contain both the sizing agent (A) and the retention agent (B).
• the emulsions or dispersions are diluted so that a glue liquor is formed which (A) 0.02 to 0.4, preferably 0.05 to 3, in particular 0.05 to 1 percent by weight of sizing agent (calculated as dry matter), based on the total weight the aqueous glue liquor, the sizing agent optionally being in salt form, and (B) 0.01 to 0.2, preferably 0.05 to 0.1, in particular 0.3 to 0.8 percent by weight retention agent (calculated as dry substance) on the total weight of the aqueous glue liquor.
• pulp suspensions of the most varied types can be easily processed into paper in mass sizing with relatively particularly small amounts of sizing and retention agents, which have good sizing properties (alkali drop sample, ink floating time and, above all, water absorption according to Cobb ) having.
• This also applies to surface sizing, where the good sizing effects are achieved even with small area orders of sizing and Retention agents can be achieved.
• the low area applications enable a quick working process, so that good surface sizes can be achieved within 20 to 40 seconds at the drying temperature of 90 to 110 ° C, for example.
• the paper sized according to the process has good mechanical properties, ie good strengths, in particular good tear strength.
• pulp suspensions containing wood pulp or waste paper can be processed for mass sizing.
• the compatibility of the sizing agent used according to the invention with various fillers such as chalk and also various additives of the type specified above is also advantageous.
• the sizing and retention agents used according to the invention have good compatibility with the customary auxiliaries used in the paper industry, such as dyes, pigments, binders, in particular optical brighteners and other additives.
• the sizing and retention agents used are easily accessible, inexpensive and do not tend to form undesirable foams.
• the degree of whiteness of the sized paper is not significantly influenced by the sizing and can even be improved in both the mass and the surface sizing. Above all, the generally surprisingly high storage stability of the size dispersions of the type indicated is of great advantage.
• Example 1 A solution of 9.6 parts of trimellitic anhydride (0.05 mol) and 25 parts of the distearylamine (0.05 mol) specified in instruction A are dissolved in 180 parts of a xylene mixture, heated to the reflux temperature of approx. 145 ° C. and kept at this temperature with stirring for 32 hours. The solvent is then distilled off under reduced pressure. 33 parts of the compound which essentially corresponds to the formula (5) are obtained as a light brown, viscous wax. M.p .: 18-24 ° C. Acid number: 168.
• Example 2 A solution of 50 parts of the technical distearylamine (0.1 mol) specified in regulation A in 150 parts of toluene is mixed with 21 parts of citric acid monohydrate (0.1 mol) and heated to the reflux temperature of approx. 111 ° C. wherein the water released by the reaction is separated from the reaction mixture with a water separator, which takes about 17 hours. The solvent is then distilled off under reduced pressure. 75 parts of the compound which essentially corresponds to the formula (6) are obtained as a light brown paste. Acid number: 159.
• EXAMPLE 3 The procedure is as described in instruction C, but 11.2 parts of itaconic anhydride (0.1 mol) are used (instead of 11.4 parts of glutaric anhydride). 60 parts of the compound which essentially corresponds to the formula (10) are obtained as a brownish powder. M.p .: 39-40 ° C. Acid number: 88.
• EXAMPLE 4 The procedure is as described in instruction C, but 11.2 parts of citraconic anhydride (0.1 mol) are used (instead of 11.4 parts of glutaric anhydride). 60 parts of a compound which essentially corresponds to the formula (11) are obtained as a light brown powder. M.p .: 35-38 ° C. Acid number: 85.
• Examples 5 to 8 A pulp suspension of bleached birch sulfate pulp and pine sulfate pulp in a weight ratio of 1: 1 in water of 10 ° dH (German degrees of hardness), which has a Schopper-Riegler freeness of 35 ° and a solids content of 0.5%, is included 20% chalk as a filler and then 0.01% PERCOL ® 292 (cationic, high molecular weight (MW> 1.10 7 ) polyacrylamide) as an aid for retaining the finest cellulose fiber particles, the pH of the pulp suspension given in Table I below being established .
• the percentages relate to dry matter of auxiliaries and fillers, based on the solids content of the fiber suspension.
• Formulations of the sizing agent are prepared by in each case 7% of the stated sizing agents in powder form, as are obtained in the production, with 3.5% each of POLYMIN® P (polyethyleneimine with a molecular weight of 10,000 to 100,000) as the retention agent in the presence of deionized water and glass beads with a diameter of 2 mm at room temperature (15 to 25 ° C).
• POLYMIN® P polyethyleneimine with a molecular weight of 10,000 to 100,000
• the dispersions obtained are pourable, homogeneous and stable in storage. The percentages indicate the dry matter content of sizing and retention agent, based on the total weight of the formulation.
• the aqueous formulation of the sizing agent and the retention aid is added to the fibrous suspension in such a way that 0.5% of the dry matter of the sizing agent, based on the solids content of the fibrous suspension, is formed.
• the fiber suspension is then processed in a laboratory sheet former "Formette Dynamique" from Allimand, Grenoble, France, to paper sheets which, after drying at 130 ° C. for 3 minutes, have a basis weight of 80 g / m 2 .
• Both surfaces of the paper sheets obtained ie the surface obtained on the screen side of the sheet former and the opposite or top side, are tested for their sizing properties.
• the water absorption according to Cobb is measured after 30 seconds exposure (WA Cobb 3 o) according to DIN 53 132.
• the results of the WA Cobb 30 measurements in g / m 2 of the sieve side (SS) and top side (OS) after drying at 130 ° C and after storage for one day at 23 ° C and a relative humidity of 50% are in given in Table I below.
• WA Cobb 3 o values over 100 correspond to a completely unsatisfactory sizing of the paper.
• Examples 10 to 15 The procedure is as given in Examples 5 to 9, but the sizing agent and the retention agent are added separately to the fiber suspension, the stated amount (in%) of sizing agent in powder form at room temperature (15 to 25 ° C.) in the presence of water and glass beads are stirred with an aqueous, 5% ammonia solution to form a self-emulsifying, also pourable, homogeneous and storage-stable emulsion, and the in the after Formulations of the sizing agent given in Table II below.
• the Val% indicated mean the number of equivalents of ammonia for 100 equivalents, based on the number of acidic groups present in the sizes used.
• the fiber suspension is mixed with the specified amount of dry substance of the sizing agent, the amount of sizing and retention agent being based on the solids content of the fiber suspension.
• the sizing results are also shown in Table II. When using 10 to 300 val% ammonia or sodium hydroxide (as a 5% aqueous solution) for formulating the sizing agent, similarly good sizing results are obtained as those given in Table II.

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• 1985
  • 1985-09-09 EP EP85810407A patent/EP0174911A1/de not_active Withdrawn
  • 1985-09-09 US US06/773,708 patent/US4737239A/en not_active Expired - Fee Related
  • 1985-09-11 FI FI853475A patent/FI853475L/fi not_active IP Right Cessation
  • 1985-09-12 ES ES546900A patent/ES8700361A1/es not_active Expired
  • 1985-09-12 ZA ZA856981A patent/ZA856981B/xx unknown
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  • 1985-09-12 NO NO853575A patent/NO853575L/no unknown
  • 1985-09-12 AU AU47393/85A patent/AU4739385A/en not_active Abandoned
  • 1985-09-12 DK DK414985A patent/DK414985A/da not_active Application Discontinuation
  • 1985-09-13 JP JP60203241A patent/JPH0830315B2/ja not_active Expired - Lifetime
• 1995
  • 1995-03-08 JP JP7047983A patent/JP2559570B2/ja not_active Expired - Lifetime

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