FI69160C - LIMITING CONTAINER WITH VAT - Google Patents

Abstract

Described are sizing compositions in the form of aqueous dispersions comprising a hydrophobic cellulosereactive sizing agent such as a ketene dimer, fortified rosin and a water-soluble, nitrogen-containing cationic dispersing agent. The compositions are highly efficient internal or surface sizing agents for paper and maximize the advantages of each sizing component while minimizing the disadvantages.

Description

691 60

AQUATIC ADHESIVE MIXTURES - VATTENHALTIGA LIMNINGS-KOMPOSITIONER

This invention relates to paper sizing compositions, and more particularly to aqueous compositions containing hydrophobic, cellulose-reactive sizing agents and reinforced rosin.

Aldrich is disclosed in U.S. Pat. 3,966,654 described aqueous dispersions containing finely divided reinforced resin particles, a water-soluble cationic resin dispersant and water. Aqueous dispersions of reinforced resin are suitable as internal paper sizing agents and paper surface sizing agents. However, the gluing behavior depends on both pH and concentration, and in order to obtain a good gluing performance, it is necessary to use more than 0.1% of reinforced resin based on the dry weight of the pulp (critical level) and to glue under acidic conditions.

Adhesive compositions which are aqueous emulsions or aqueous dispersions of a hydrophobic cellulose-reactive sizing agent, such as a ketene dimer, and a nonionic, anionic or cationic dispersant are also known. Cellulose-reactive sizing agents, and especially ketene dimer sizing agents, have become commercially important because they allow sizing to be performed under basic conditions that do not adversely affect paper strength, and more effective sizing can be achieved at a lower critical level than with resin resins. However, they have one serious drawback, since the development of the initial gluing requires drying and the expected final gluing does not develop for a long time depending on the conditions used.

691 60 2

In order to accelerate the development of sizing, it has been proposed that certain water-soluble thermosetting plastics be used in dispersions in connection with cellulose-reactive sizing agents. Mixtures of this type are described, for example, in British Patent Publication no. 1,533,434 and U.S. Pat.

4,240,935. Although these blends represent a substantial improvement in the rate of adhesive development, complete drying is still required to achieve the final bonding. However, in the case of wood pulp and other difficult-to-glue joints, a maturing time is required to achieve the final gluing.

According to the present invention, there are now provided aqueous dispersions containing both reinforced rosin and cellulose-reactive sizing agents, which can surprisingly overcome the disadvantages associated with the situation where one of the two ingredients is used alone. The dispersions of this invention also contain the advantages of the individual ingredients and, in addition, allow gluing to be better and faster than would be expected for either ingredient alone.

The aqueous dispersions of this invention comprise, as a continuous phase, an aqueous solution containing at least one water-soluble, nitrogenous, cationic dispersant, and the dispersed phase is (a) fine reinforced rosin particles and (b) finely divided hydrophobic cellulose organic acid anhydrides, organic isocyanates or mixtures thereof, and the weight ratio (a) :( b) in the dispersed phase is in the range of 0.1: 1 to 10: 1 and the amount of dispersant is in the range of about 5 to 140% based on the weight of the dispersed phase.

The reinforced rosin contained in the dispersed phase is 3,69160 resin and the following group of rosin

> c = c-c = o I I

a reaction product of an acidic compound containing a rosin prepared by reacting a rosin and an acidic compound at a temperature in the range of about 150 to 210 ° C.

The acidic compound is used in an amount to provide a reinforced rosin containing about 1-12% by weight of the incorporated acidic compound based on the weight of the reinforced rosin. Methods of making a reinforced resin are claimed and described in U.S. Pat. 2,628,918 and 2,684,300, which are incorporated herein by reference.

Examples of compounds containing the group> C = C-C = 0

I I

and which can be used in the preparation of the reinforced resin are e.g. alpha-beta-unsaturated organic acids and their available anhydrides, exemplified by e.g. fumaric acid, malic acid, acrylic acid, malic anhydride, itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride. If desired, acid mixtures can be used in the preparation of the reinforced resin. If desired, mixtures of different reinforced resins can also be used. Thus, for example, a mixture of rosin and acrylic acid adjuvant and rosin and fumaric acid admixture can be used in the preparation of the dispersions of the present invention. It is also possible to use a reinforced resin which is practically completely hydrogenated after the formation.

In the reinforced rosin, known fillers such as waxes (especially paraffin wax and microcrystalline wax), including hydrocarbon resins, including those derived from petroleum hydrocarbons and terpene, etc. may be used in the reinforced rosin, for example. by weight of resin resin.

Mixtures of reinforced rosin and rosin and mixtures of reinforced rosin, rosin resin and rosin filler can also be used. Mixtures of reinforced rosin and rosin contain about 25-95% reinforced rosin and about 75-5% rosin. Mixtures of reinforced rosin, rosin and rosin filler contain about 25-45% reinforced rosin, about 5-50% rosin and about 5-50% rosin filler.

If the rosin (i.e., unreinforced rosin) is used in conjunction with the reinforced rosin, it may be of any type of rosin on the market, such as rosin, gums, tall oil rosin, or a mixture of one or more thereof in impure or purified form. Partially or practically fully hydrogenated rosin and polymerized rosin as well as rosin treated with e.g. heat or formaldehyde to prevent crystallization may be used.

There are aqueous dispersions on the market which contain reinforced resin in the form of fine particles.

Aldrich has described in U.S.A.

3,966,654 is a process for preparing such dispersions, in which the fortified rosin is first dissolved in a water-immiscible organic solvent in which it is soluble, such as, for example, benzene, xylene, chloroform, methylene chloride or 1,2-dichloropropane. If desired, a mixture of one or two solvents may be used. The solvent must also be chosen so that it does not subsequently react with the ingredients contained in the aqueous dispersion prepared 691 60 5. The solution of the organic solvent and the fortified rosin is then mixed with an aqueous solution containing a cationic dispersant to give an emulsion which is substantially unstable and which contains the solution of the organic solvent and the fortified rosin as a dispersed phase. This substantially unstable aqueous emulsion is then subjected to very strong abrasion to obtain a substantially stable aqueous emulsion. Vigorous abrasion is preferably achieved with a homogenizer. Thus, when the volatile aqueous emulsion is passed through the homogenizer at least once at a pressure between about 6894 and 55152 kPa (about 1000 to 8000 psig), a virtually stable emulsion is obtained. The organic solvent is then removed from the emulsion to obtain a substantially stable aqueous dispersion of reinforced resin particles. Alternatively, the solution of the organic solvent and the fortified resin can be mixed with the aqueous solution of the cationic dispersant in an amount to obtain a stable water-in-oil emulsion, which is then converted to a stable oil-in-water emulsion by adding water with vigorous stirring. The organic solvent is then removed, e.g. by distillation under reduced pressure.

The dispersant can be any known dispersant used in resin adhesives and is nonionic, anionic or cationic in nature. Highly preferred are cationic, thermosetting, water-soluble polyaminopolyamide epichlorohydrin resins, alkylene-polyamine epichlorohydrin resins and poly (diallylamine) epichlorohydrin resins. These resins are described in U.S. Pat. 2,926,116, 2,926,154 and 3,700,623 and 3,966,654.

6,691 60

Aldrich describes in U.S.A. No.

3,817,768 another method for preparing aqueous dispersions of wadded resin. In this method, an unstable aqueous dispersion containing fortified rosin and a small amount of a rosin salt as a dispersant is first formed, the unsteady dispersion is heated to about 150-195 ° C and then the heated dispersion is subjected to very high friction, e.g. by passing it through a homogenizer. (about 2000 to 8000 psig) so as to obtain a virtually stable dispersion. Australian patent publication no. 483 349 mentions that other anionic dispersants such as alkylarylsulfonic acid salts, salts of dialkyl esters of sulfosuccinic acid, salts of alkyl halides of sulfuric acid and salts of alkylphenoxy (polyethyleneoxy) sulfuric acid with ethanol half esters can also be used in this process.

Hughes et al. are described in U.S. Patent No. 4,847,607.

4,199,369 describe another suitable method for preparing aqueous dispersions of reinforced rosin. This method is a reversal process in which an aqueous solution of certain water-soluble anionic dispersants is added to a molten fortified resin with continuous stirring to form a water-in-oil emulsion and then water is added with vigorous stirring until the emulsion is inverted and the water becomes a continuous phase and resin dispersed. Preferred dispersants for use in the translation process described in this U.S. patent include alkali metal or ammonium salts of alkylphenoxy or higher alkoxy-poly (ethyleneoxy) ethanol half-esters of sulfuric acid.

Hydrophobic, cellulose-reactive sizing agents which have been found to be very useful as a second component of the dispersed phase include ketene dimers, acid anhydrides and organic li 7 69160 isocyanates.

The ketene dimers used as cellulose-reactive sizing agents have the formula [R * '' CH = C = O] 2 wherein R'1 'is a hydrocarbon group such as an alkyl group having at least 8 carbon atoms, a cycloalkyl group having at least 6 carbon atoms, an aryl group, an Aralkyl group or alkaryl. When designating ketene dimers, the group "R" is indicated first, followed by the designation "ketene dimer". Thus, the phenyl ketene dimer is

^ CH = C = Q

-> 2 'and the benzyl ketene dimer is ^ - CH2-CH = CaO J2 and the decyl ketene dimer is [C ^ qH21-CH = C = o72 · Examples of 8 69160 ketene dimers are e.g. octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, phenyl, benzyl, beta-naphthyl and cyclohexyl ketene dimers and ketene dimers prepared by known methods montanic acid, naphthenic acid, '-decylenic acid', 'dodecylenic acid', palmitic oleic acid, oleic acid, castor oleic acid, linoleic acid and oleostearic , in beef fat, lard and whale fat. Mixtures of any of the above fats may also be used.

Acid anhydrides used in paper as cellulose-reactive sizing agents are well known in the art and include e.g. (A) resin anhydride, which is described in U.S. Pat.

3,582,464; (B) anhydrides having the following structure

(I) E1 "CC

R -c / ° wherein R 1 is a saturated or unsaturated hydrocarbon group such that the hydrocarbon group is a straight-chain or branched alkyl group, an aromatic-substituted alkyl group or an alkyl-substituted aromatic group, and the hydrocarbon group is so long as to contain a total of about 14 to 36 carbon atoms; and (C) cyclic dicarboxylic anhydrides of formula tt 691 60 9 (ΙΙ) ϊ

A

R "-R 'O

wherein R 'is a dimethylene or trimethylene group and R "is a hydrocarbon group containing more than 7 carbon atoms and preferably alkyl, alkenyl, aralkyl or aralkenyl. Substituted cyclic dicarboxylic anhydrides of formula (II) include substituted succinic acid. - and glutaric anhydrides In the above formula (I), each group R 1 may be the same hydrocarbon group, or each group R 1 may be a different hydrocarbon group.

Specific examples of the anhydrides of formula (I) include myristoyl anhydride, palmitoyl anhydride, oleoyl anhydride and stearoyl anhydride.

Specific examples of the anhydrides of formula (II) include isooctadecenyl succinic anhydride, n-hexadecenyl succinic anhydride, dodecyl succinic anhydride, decenyl succinic anhydride, octenyl succinic anhydride, octenyl succinic anhydride.

The hydrophobic organic isocyanates used in paper sizing are well known in the art. The best results are obtained when the hydrocarbon chains of the isocyanates contain at least 12 carbon atoms, preferably 14 to 36 carbon atoms. Such isocyanates include e.g. resin isocyanate, dodecyl isocyanate, octa-decyl isocyanate, tetradecyl isocyanate, hexa-decyl isocyanate, eicosyl isocyanate, docosyl isocyanate, 6-ethyldecyl isocyanate, 6-ethyl isocyanate, 6-phenyl such as 1,18-octadecyl diisocyanate and 1,12-dodecyl diisocyanate, in which one long chain alkyl group serves two isocyanate groups and imparts hydrophobic properties to the whole molecule.

Aqueous dispersions or emulsions are available on the market which contain hydrophobic cellulose-reactive fine sizing particles. Such dispersions are usually prepared by mixing a cellulose-reactive sizing agent with an aqueous solution containing an emulsifier, and then passing the premix through a homogenizer. Suitable emulsifiers for use in this connection are those commonly used in emulsions of cellulose-reactive sizing agents. Such emulsifiers include e.g. cationic starches which are water-soluble starches and contain a sufficient number of amino groups, quaternary ammonium groups or other cationic groups to make the whole starch adhere to cellulose. Such cationic starches include, for example, the cationic amine-modified starches described in U.S. Pat. 3,130,118, and known cationic starch-graft copolymers. Other emulsifiers include water-soluble cationic thermosetting resins obtained by reacting epichlorohydrin with a water-soluble aminopolyamide consisting of a dibasic carboxylic acid having 3 to 10 carbon atoms and polyalkylene polyamine having 2 to 8 alkylene groups and 2. 2,926,154), or with water-soluble poly (di-allylamine) (cf. U.S. Patent No. 3,966,654), or with a condensate between dicyandiamide or cyanamide and polyalkylene polyamine 11,691,160 (cf. U.S. Patent No. 3,403,113). ), or with bis-aminopropylpiperazine or a condensate thereof and dicyandiamide or cyanamide (U.S. Patent No. 4,243,481), and the like.

The dispersed phase of the cationic aqueous dispersions of this invention contains both a hydrophobic cellulose-reactive sizing agent in the form of fine particles and a reinforced rosin in the form of fine particles, and it has been found that the dispersed phase should contain at least 10% by weight of each. Thus, the weight ratio of reinforced rosin: cellulose-reactive sizing agent is in the range of 0.1: 1 to 10: 1. However, the most practical and preferred range is 0.2: 1 to 5: 1.

As already mentioned above, the aqueous dispersions according to the invention also contain a water-soluble, nitrogen-containing cationic dispersant. In this connection, any cationic nitrogen-containing dispersant which is water-soluble and which gives the dispersed particles a positive surface charge is suitable for use. Nitrogenous dispersants of this type are well known in the art and are commercially available. Typical dispersants include quaternary ammonium compounds; homopolymers or copolymers of ethylenically unsaturated amines; resinous reaction products formed by epihalohydrins with polyaminopolyamides, alkylenepolyamines, poly (diallylamines), bis-aminopropylpiperazine, dicyandiamide or cyanamide polyalkylene polyamide amide di-diphenamide amide condensates, dicyandiamide or cyanamide formates and cationic starches and in particular starch ethers containing amino or quaternary ammonium groups. Highly preferred are cationic starch 12 6 916 0 and resinous reaction products formed by epichlorohydrin with aminopolyamide, alkylene polyamine, poly (diallylamine) or dicyandiamide polyalkylene polyamine condensate. Dispersants can be used alone or in combination with each other or in combination with anionic or nonionic dispersants.

The cationic dispersant must, of course, be used in at least an amount such that the dispersion is cationic. The amount used will, of course, vary with the water solubility and cationic strength of the substance in question. The amount is usually in the range of about 5 to 140, preferably 20 to 120 and most preferably 40 to 100% by weight based on the weight of the dispersed phase. If the amount is less than about 5%, it is generally not sufficient to make the dispersion cationic, and amounts greater than 140% have not been found to bring any additional benefits, so they are unnecessary.

The cationic dispersions of this invention can be prepared at any suitable concentration. Particularly useful are dispersions in which the amount of dispersed phase is about 5 to 70%, preferably 10 to 55%, the amount of dispersant is 1 to 15%, preferably 2 to 10% and the remainder up to 100% water. The dispersions of this invention may also contain other sizing agents or agents whose properties are not actually related to sizing, provided that their presence does not destroy the advantages of the invention. Alum is very useful in this context, as it is commonly used for bonding resin adhesive. Usually, alum cannot be added to the reinforced rosin before it is used as a paper sizing agent, but must be added separately to the aqueous suspension of papermaking fibers at different stages before sheet formation in the case of internal sizing and before resin treatment, simultaneously with or after external sizing. It has now been found that the n 1 3 691 60 cationic aqueous dispersions according to the present invention can contain any amount of alum without destroying the sizing power, and that the presence of alum offers a very high operating advantage which could not be achieved before. If alum is used, it is generally present in an amount of about 25 to 200% by weight of the particulate reinforced resin. However, the most practical and priority range is 75-150%. Other additives, such as preservatives, may also be present in small amounts.

The novel dispersions of this invention can be prepared by mixing a preformed cationic dispersion of reinforced rosin particles and a preformed cationic dispersion of a hydrophobic cellulose-reactive sizing agent. They can also be prepared by mixing the molten or organic solution of the reinforced rosin and the cellulose-reactive sizing agent in an aqueous solution containing a cationic dispersant, and then subjecting the mixture to very high friction, as described above. The measures described above may also be modified and are within the general knowledge of the field covered by this invention.

The dispersions which are the subject of the present invention are very useful in internal sizing and surface sizing of paper and can be used to maximize the advantages of the individual sizing ingredients while keeping the disadvantages to a minimum. The dispersions provide better adhesion under conditions that are not applicable to dispersions of cellulose-reactive sizing agents alone or to reinforced resin dispersions alone, and also achieve the rapid cure typical of reinforced resin adhesives and the effective adhesion typical of cellulose-reactive adhesives. Thus, with the present invention, it is possible to easily control the degree of gluing and its rate under normal paper mill conditions, in which alum is usually present, and to use pH values that provide very durable and durable paper. The aqueous dispersions can be added to the pulp suspension prior to sheeting at any stage after the cleaning is completed, or it can be applied to the sheet in a paper machine, such as a size press. For either of these uses, it is not necessary to prepare an aqueous dispersion in advance and similar advantages are obtained when the dispersion is prepared in situ, i.e. a sheet formation. Likewise, the aqueous dispersions of this invention can be formed in situ with a size press by adding the individual cationic components simultaneously or separately in dispersion form and mixing.

An amount of dispersion should be added to the aqueous suspension of the pulp (internal sizing) or formed paper sheet (external sizing) such that the combination of cellulose-reactive sizing agent and reinforced resin retains about 0.01 to 1%, preferably about 0.01 to 0.5% by dry weight of the fiber. calculated.

In connection with the above general description of embodiments of the invention, detailed examples illustrating the invention are set forth below. All parts and percentages are by weight unless otherwise indicated.

of 691 60 15

Example A

A ketene dimer dispersion was prepared as follows, with a total solids content of 15%, 5.4% ketene dimer as a solid, 1.4% cationic starch, and 8.2% cationic resin prepared by condensing 1 mole of dicyandiamide and 1 mole of diethylenetriamine and reacting the condensate with 1.2 moles of epichlorohydrin.

An emulsion of the ketene dimer formed from palmitic and stearic acid was prepared by first mixing 880 parts of water, 50 parts of cationic corn starch and 10 parts of sodium lignin sulfonate. The pH of the mixture was adjusted to 3.5 by the addition of about 3.5 parts of 98% sulfuric acid and then the mixture was heated at 90-95 ° C for about 1 hour. Water was then added to the mixture to a total of 1760 parts (total weight). Then, 240 parts of ketene dimer were mixed in and the mixture (65 ° C) was homogenized by passing once through a homogenizer at 27576 kPa (4000 psi). The homogenized product (total solids 15% and solid ketene dimer 12%, 136.4 parts) was then mixed with 136.4 parts of an 18% aqueous solution of cationic resin and 27.2 parts of water, and the pH was adjusted to 4.0 to 4.5.

Example B

A cationic dispersion of reinforced rosin was prepared in the following manner with a total solids content of 34.1% and containing 28.4% of solid rosin and 5.7% of a cationic resin prepared by reacting 1.25 moles of epichlorohydrin with an aminopolyamide. obtained from 1 mole of adipic acid and 0.97 mole of diethylenetriamine.

691 60 16 300 parts of reinforced resin were dissolved in 200 parts of methylene chloride over 20 minutes. The fortified rosin contained 7.5% fumaric acid, which was practically in a completely combined form. The reinforced rosin was prepared by combining 22.5 parts of fumaric acid with 277.5 parts of formaldehyde-treated tall oil resin, maintaining the reaction mixture at about 205 ° C until virtually all of the fumaric acid had reacted, and then cooling the fortified rosin to room temperature. A solution of the reinforced resin was thoroughly mixed with 480 parts of an aminopolyamide / epichlorohydrin resin having a solids content of 12.5% and 260 parts of water, and the mixture was homogenized twice at a pressure of 20682 kPa (3000 psi). The methylene chloride was then removed by distillation under reduced pressure at 60 ° C.

When the product was cooled and filtered through a 100 mesh screen, 750 parts of a dispersion with a viscosity of 51 cP were obtained.

Examples 1-8

The various mixtures were prepared by mixing together 50 parts of the cationic dispersion of Example A and about 9-44 parts of the cationic dispersion of Example B in a mixing vessel equipped with a magnetic stirrer. Details of these examples and the cationic dispersions obtained are given in Table I below.

691 60 17

table 1

Relation Example 1 Example 2 Example 3 Example 4

Eg A (parts) 50 50 50 50

Eg B (parts) 15.1 43.9 10.9 58.7

Dispersed phase

Reinforced resin ^ 6.60 13.28 5.08 15.34

Ketene dimer ^ 4.19 2.90 4.48 2.51

Resin-resin polymer weight ratio 1.6 4.6 1.1 6.1

Continuous phase

Dispersant ^ ^ 8.65 7.74 8.85 7.47

Water (1) 80.6 76.1 81.6 74.7 (2)

Dispersant as% of dispersed phase 80.2 47.8 92.6 41.8

Total solids% 19.72 23.96 18.47 25.30

Table 1 (continued)

Relation Example 5 Example 6 Example 7 Example 8

Eg A (parts) 50 50 50 50

Eg B (parts) 28.6 36.6 18.6 9.3

Dispersed phase

Reinforced resin ^ 10.33 12.00 7.70 4.4 5

Ketene dimer 3.47 3.15 3.98 4.60

Resin resin dimer weight ratio 3.0 3.8 1.9 1.0

Continuous phase

Dispersant ^ ^ 8.14 7.92 8.50 8.93

Water (1) 78.1 76.9 79.8 81.0 (2)

Dispersant as% of dispersed phase 59.0 52.3 72.8 98.7

Total solids% 21.95 23.09 20.04 17.86 18 69160

Footnotes to Table I: (1)%, by weight of mixture (2) Cationic starch, cationic resin which is the reaction product of dicyandriaride, diethylenetriamine and epichlorohydrin, and cationic resin which is the reaction solvent of adipic acid, diethylenetriamine and epichlorohydrin.

Example 9

The sizing efficiencies of the cationic aqueous dispersions of Examples 1-5 were tested by preparing handmade test sheets which thus contained varying amounts of sizing agent. To make handmade sheets, a mixture of 50 parts bleached Rayonier softwood sulphate pulp and 50 parts bleached Weeyerheuser hardwood sulphate pulp was suspended in standard hard water and ground in a Noble and Wood grinding Hollander at a concentration of 0.5% free-slurry. To 2 liter aliquots of this slurry was added a cationic dispersion to achieve different percentages of adhesive content, as well as enough papermaking alum to give a concentration of 0.5% alum based on pulp weight, which was then diluted to 0.25% consistency to give 2 a 70 g / m (40 pound / ft) sheet at pH 6.5 using a Noble and Wood sheet machine. The formed sheets were compressed to a solids content of 33% and then dried in a steam drier at 105 ° C for 45 seconds to achieve a moisture content of 3-4%. The adhesion properties of the sheets were tested using the Hercules adhesion test with test solution no. 2 80% to reflectance. Post-removal results were measured within a two minute imaging time and the results of the matured product were measured after keeping the product for 7 days at room temperature and 50% relative humidity. The 691 60 19 adhesion results obtained in these experiments and the corresponding results obtained in 7 comparative experiments using the dispersions of Example A or Example B are shown in Table II.

Table II

Adhesive mixture, Adhesive-Hercules gluing test (s) example amount {%) After removal from the machine After natural maturation _ 0.25 393 537 2 0.30 317 434 3 0.30 540 739 4 0.275 185 175 5 0.35 514 694 A 0.075 (1) 1 1 A 0.10 (1) 10 12 A 0.15 (1) 247 320 A 0.20 ^ 428 579 B 0.10 0 0 B 0.20 3 2 B 0.40 62 64 ^ Excluded as a papermaking tray.

Example 10

The aqueous dispersions of Examples 6-8 were used to make internally sized paper on a pilot-size paper machine. The paper was made from a 50:50 blend of hardwood and softwood sulfate pulp, ground to a freeness number of 500, and formed at pH 6.4 to 6.6 sheets with a basis weight of 70 g / m (40 pounds / ft). Each dispersion was added to the thick mass just prior to dilution in a vane pump. If a papermaking alum was used, it was added at the same time as the dispersion. The glued sheets were dried to a moisture content of 3% before the size press and to a moisture content of 4% by roller. The glue press contained a 6% solution of oxidized corn starch. Adhesion was measured by the Hercules gluing test with test solution no. 2 to 80% reflectance before glue press, on a roller (after removal from the machine) and after 7 days at room temperature at 50% relative humidity.

Table III shows the adhesion results from these experiments and 6 comparative experiments carried out in the same manner, but by adding to the thick mass the dispersion according to Example A or Example B.

Table III

Hercules Adhesion Test (s) _ Usage- Before Adhesive- Machine removal natural

Bonding the mixture, the amount of alum in the press after maturation

Mixture example no. (%) (%) After _________ '1 6 0.16 0.25 9 22 114 2 6 0.32 0.25 170 220 745 3 7 0.225 0.25 33 73 492 4 8 0.35 0.25 611 391 947 5 A 0.125 - 47 34 90 6 A 0.25 - 597 560 950 7 A 0.125 0.25 0 0 86 8 B 0.10 0.25 0 0 0 9 B 0.20 0.25 5 6 6 10 B 0.20 0.50 18 55 55

It is clear from the above table that the use of the compositions according to the invention achieves a considerable improvement in adhesion under conditions which cannot be used with ketene dimer dispersions alone (Comparative Experiment 7) or reinforced resin dispersions alone (Comparative Experiments 8 and 9). The results further show that the compositions of this invention achieve the rapid cure typical of resin resins and the high level of adhesion typical of ketene dimer adhesives, and that the rate and degree of adhesion can be easily adjusted under normal paper mill conditions, usually using alum, and using very stable pH values. durable paper.

Example C

A dispersion with a total solids content of 51% and containing 21.2% of reinforced rosin, 4.3% of the cationic resinous reaction product of Example B and 25.5% of alum was prepared by mixing 50 parts of the resinous compound of Example B together. dispersion and 17.1 parts of alum (Al2 (SO2) ^ -181 ^ 0).

Examples 11 and 12

Two mixtures were prepared by mixing 50 parts of the cationic dispersion of Example A and 30 parts (Example 11) or 60 parts (Example 12) of the dispersion of Example C in a vessel equipped with a magnetic stirrer. The mixture of Example 11 contained 7.95% reinforced rosin, 3.41% ketene dimer, 7.58% cationic dispersant and 9.56% alum based on the total weight of the mixture and had a total solids content of 28.5%. The cationic dispersion of Example 12, based on the total weight of the mixture, contained 11.56% reinforced rosin, 2.48% ketene dimer, 6.68% dispersant mixture and 13.90% alum and had a total solids content of 34.6%.

69160 The paper surface sizing ability of the aqueous dispersions of these examples was evaluated using an adhesive-free, bleached kraft paper of 70 g / m (40 libs / ft) prepared at pH 6.5. The sheets were treated with the aid of a small horizontal laboratory adhesive press so that water dispersion samples were added to the contact area between the adhesive press rolls and the paper sheets were passed through the dispersion before being pressed between the adhesive press rolls. Under these conditions, the sheets assumed an adhesive dispersion of about 70% by weight. The glued sheets were dried for about 20 seconds at 93 ° C to a moisture content of about 5%. Adhesion was determined by the Hercules gluing test using test solution no. 2 to 80% reflectance within 2 minutes of dry time (after removal from the machine) and after storage for 7 days at room temperature at 50% relative humidity. Table IV shows the results of the experiments according to these examples and five comparative experiments in which the paper was treated in the same way, but the dispersion according to Example A, B or C was used in the sizing mixture.

li 691 60 23

Table IV

Hercules adhesion test (s) _

Adhesive mixture, Added Machine take-off Natural ripening example quantity (%) after_ after application_ 11 0.21 23 320 12 0.175 8 35 A 0.035 0 5 A 0.07 4 160 B 0.07 0 0 B 0.07 (1) 7 15 C 0.14 8 14 ^ 0.07 % alum, based on the weight of the dry pulp, was added to the contact area between the rolls of the size press granule as an aqueous solution simultaneously with the dispersion according to Example B.

Claims (9)

A cationic aqueous dispersion for gluing, comprising water, a water-soluble, nitrogen-containing cationic dispersant and suspended particles which are a cellulose-reactive ketene dimer adhesive, a cellulose-reactive reinforced organic acid anhydride adhesive or a cellulose-reactive organic anhydrous adhesive resin adhesive particles having a weight of at least one tenth of the weight of the cellulose-reactive adhesive and not more than ten times the weight of all suspended adhesive particles from 5 to 70% by weight of the aqueous suspension and from 5 · 1 to 0% by weight of the dispersant weight and 1 to 15% by weight of the aqueous suspension. Aqueous dispersion according to Claim 1, characterized in that the aqueous dispersion also contains about 25 to 200% of alum, based on the weight of the resin particles. Aqueous dispersion according to Claim 1, characterized in that the cellulose-reactive sizing agent is a ketene dimer. Aqueous dispersion according to Claim 3, characterized in that the dispersant can be a cationic starch and a resinous product formed by the reaction of epichlorohydrin with an aminopolyamide, an alkylene polyamine, a poly (diallylamine) or a dicyandiamide-polyalkylene polyamine condensate. A method for gluing paper or board obtained from pulp, characterized in that an aqueous dispersion according to claim 1 is added as a sizing agent in the gluing apparatus of a paper machine. A method according to claim 5, characterized in that the gluing process is an internal gluing process. A method according to claim 5, characterized in that the gluing process is a surface gluing process. 691 60 Paper or paperboard, characterized in that it consists of sheet-shaped cellulosic fibers glued with an aqueous dispersion according to claim 1. Product according to Claim 8, characterized in that the cellulose fibers are internally glued. Product according to Claim 8, characterized in that the cellulose fibers are surface-glued. PATENTKRAV 6 916 0