NO149477B - PROCEDURE FOR THE PREPARATION OF LIMITED PAPER AND THE LIMIT FOR USE IN THE PROCEDURE - Google Patents

Description

The present invention relates to a method for the production of glued paper in which an aqueous emulsion of a hydrophobic cellulose-reactive adhesive is used.

More particularly, the invention relates to the production of glued paper and cardboard where the adhesive used is a hydrophobic cellulose-reactive adhesive, such as a ketene dimer adhesive, and which is used in combination with a new adhesive accelerator, so that a higher binding capacity is obtained at the output of the paper machine than when said cellulose-reactive adhesive is used alone.

The invention also relates to an adhesive for cellulose fibers,

essentially consisting of an aqueous emulsion of a hydrophobic cellulose reactive adhesive.

US-PS .3.8 40,486 describes water-soluble, thermosetting resin compositions prepared by a reaction between dicyanidamide, an ammonium salt, formaldehyde and an acid salt of a water-soluble aminopolyamide, such as a water-soluble aminopolyamide obtained by the reaction of adipic acid with diethylenetriamine. According to the aforementioned patent, these resinous compositions accelerate the gluing obtained in paper by means of cellulose-reactive adhesives, such as ketene dimers, acid anhydrides and isocyanates. By using said resinous compositions according to US-PS 3,840,486

in combination with the above-mentioned adhesives for paper, a higher adhesive strength is obtained at the output of the paper machine than when equivalent amounts of the adhesive are used alone.

GB.PS 1,373,788 describes the use of dicyanidamide-formaldehyde condenser as adhesive accelerators for ketene dimer adhesives.

US-PS 3,409,500 describes a process for the production of Bonded paper which includes separately adding an aqueous anionic dispersion of hydrophobic, organic cellulose-reactive sizing agent carboxylic anhydric particles to an aqueous suspension of the cellulose papermaking fibers, and a water-soluble cellulose substantial cationic polyamine with a molecular weight of over 1000, and where the amount of said polyamine is at least sufficient to deposit said anhydride particles on said fibers and to accelerate the rate at which said anhydride develops its adhesive properties on the cellulose fibers at temperatures from 90-120 °C, after which the suspension is formed into sheets so that a water-deposited band is formed, after which this is dried at temperatures between 90

and 120°C.

In US-PS 3,409,500 in column 3, lines 61-70, it is stated that among the most effective cationic polymers are adipic acid-polyalkylene polyamide-epichlorohydrin polymers, prepared by condensing adipic acid with a polyalkylene polyamine, thereby forming a polyamide polyamine , after which this polymer is reacted with epichlorhydrin. Process for the production of agents of the type described in 1 US-PS 2,926,116, 2,926,154 and 3,329,657.

The cationic polymers according to US-PS 2,926,116 and 2,926,154 are described in US-PS 3,483,077 as very useful retention agents for ketene dimer sizing agents, whereby the sizing is improved compared to cationic starch-containing retention agents.

US-PS 3:575,796 describes a method for gluing paper and cardboard products which involves intimately dispersing with an aqueous wood pulp suspension, or applying to a ready-made paper web, an aqueous emulsion of an N-substituted aziride compound which is prepared by a reaction between a carbonylsubst i tuer t, a, (3-ethylenic unsaturated compound such as distearyl maleate and an alkylene imide such as ethylene imine. The adhesive can be evenly dispersed with a cationic emulsifier such as a cationic starch to thereby obtain better attachment to the fibers. Column 4 , lines 1-44 of US-PS 3,575,796 describe other cationic agents that can be used to improve adhesion of the adhesives, and among these are cationic thermosetting resins such as the reaction products of dibasic acids, polyalkylene polyamines and epicahydrogenhydrins. also stated in column 4, lines 45-62 that cationic agents can be used as an emulsifier for the adhesive.

US-PS 3,666,512 describes compositions consisting of hydrophobic cellulose-reactive paper sizing carboxylic acid anhydrides and a catalyst which accelerates the rate at which the anhydride develops its sizing properties when this is deposited on cellulose from an aqueous medium and then heated. The catalyst or foreign agent for the anhydride sizing agent is a water-soluble cationic salt of a cellulosic substantial water-soluble polyamine. Suitable cationic agents are listed in the table in column 7

in the patent. Among the cationic agents mentioned is an aminopolyamide-epichlorohydrin resin, where said aminopolyamide is derived from diethylenetriamine and adipic acid. CD-PS 873,777 describes a method for improving the wet strength, dry strength and resistance to penetration of liquids on unglued paper which consists of saturating the paper with an amine oxide capable of swelling the paper fibers and a ketene dimer paper sizing agent, after which heats the paper to swell the paper fibers and remove the amino oxide from the paper.

US-PS 3.04 6.186 relates to the production of glued paper with the so-called Hollander addition process where an aqueous cationic dispersion of one hydrophobic ketene dimer is added to an aqueous suspension of cellulose fibers. The sized paper is prepared by forming an aqueous suspension of <±e cellulose-containing papermaking fibers and adding to this an emulsion of a hydrophobic ketene dimer to an aqueous medium containing a cationic dispersant which may be a monomeric or high molecular weight hydrophilic or water-soluble basic nitrogenous surfactant medium. Dispersants of this type are specified in columns 3 and 4 of US-PS 3,046,186.

US-PS 3,006,806 describes a simultaneous use of an organic cationic polymer and a ketene dimer in gluing paper. Exemplary cationic polymers are melamine formaldehyde resins (as disclosed in US-PS 2,345,543 et seq., US-PS 2,559,220; urea-formaldehyde resins (as disclosed in US-PS 2,657,132); cationic corn starches; guanidine-formaldehyde resins (US-PS 2,745,744); alkylene polyamine-halohydrin resins (as described in US-PS 2,601,597); and cationic urea formaldehyde resins (as described in BG-PS. 675,477 and 677,184).

US-PS 3,084,092 relates to paper produced by a . simultaneous

using an amino resin and a hydrophobic organic isocyanate. Amino resins described in US-PS 3,084,092 are polyfunctional halohydrin resins according to US-PS 2,595,934; dicyanidamine-formaldehyde-amine polymers according to US-PS 2,596,014; urea mono-substituted urea resins according to US-PS 2.6 98,787; polyamine-polyamide linear polymers according to US-PS 2,729,560; polymers formed by copolymerizing acrylamide and acrylic acid in a molar ratio of 9:1, sulfonated dimethylolurea resins according to US-PS 2,582,840; as well as aminosulfuric acid melamine-formaldehyde resins according to US-PS 2,688,607.

According to the present invention, new imaccelerators have now been found which can be used with hydrophobic cellulose-reactive agents, such as ketene dimers, acid anhydrides and organic isocyanates.

The glue accelerators used in connection with the present invention are poly-(diallylamine)-epichlorohydrin resins as indicated and described in US-PS 3,700,623.

In accordance with this, the present invention relates to a method for the production of glued paper in which an aqueous emulsion of a hydrophobic cellulose-reactive adhesive selected from the group consisting of ketene dimers, acid anhydrides and organic isocyanates is used, using in combination with the adhesive a poly(diallylamine)- epihalohydrin resin, and this method is characterized in that the poly(diallylamine) epihalohydrin resin is added in a sufficient amount to increase the adhesive effect of the adhesive,

as the paper comes out of the machine.

The invention also relates to an adhesive for cellulose fibers,

•consisting essentially of an aqueous emulsion of

a hydrophobic cellulose reactive adhesive selected from ketene dimers, acid anhydrides and organic isocyanates,

and this adhesive is characterized in that it contains an adhesive accelerator in the form of a poly(diallylamine)-epihalohydrin resin which is present in a sufficient amount to increase the adhesive properties of the adhesive on the paper as it comes out of the paper machine.

Said poly(diallylamine)-epihalohydrin resins used in the method according to the present invention consist of resinous reaction products of (A) a linear polymer with units of the following formula:

where R is hydrogen or lower alkyl and R' is hydrogen, alkyl or a substituted alkyl group, and (B) an epihalohydrin.

In the above-mentioned formula, each of the groups R may be the same or different, and may be hydrogen or lower alkyl. The alkyl groups can contain from 1-6 carbon atoms, preferably they are methyl, ethyl, isopropyl or n-butyl. R' in the formula represents hydrogen, alkyl or substituted alkyl groups, the R'-alkyl groups can contain from 1-18 carbon atoms (preferably from 1-6 carbon atoms), and can e.g. be methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, hexyl, octyl, decyl, dodecyl, tetradecyl and octadecyl.

R<1> can also be a substituted alkyl group. Suitable substituents generally include any group which will not affect the polymerization through a vinyl double bond. Typically, the substituents can be carboxylate, cyano, ether, amino (primary, secondary or tertiary), amide, hydrazide and hydroxyl.

Polymers with units of the above formula can be prepared by polymerizing hydrohalide salts of a diallylamine:

where R and R<1> are as indicated above, either alone or as • a mixture with other copolymerizable ingredients, in the presence of a free radical catalyst after which the salt is neutralized, so that the polymer-free base is obtained.

Specific hydrohalide salts of diallylamines which can be polymerized to give polymer units, which can be used in the method, according to . present invention, includes diallylamine hydrochloride, N-methyldiallylamine hydrobromide, 2,2<1->dimethyl-N-methyldiallylamine hydrochloride, N-ethyldiallylamine hydrobromide, N-isopropyldiallylamine hydrochloride, N-n-hexyldiallylamine hydrochloride, N-octadecyldiallylamine hydrochloride, N-acetamidodiallylamine hydrochloride, N-cyano--methyldiallylamine hydrochloride, N-(3-propionamidodiallylamine hydrobromide, N-carboethoxymethyldiallylamine hydrochloride, N-p-methoxyethyldiallylamine hydrobromide, N-3-aminoethyldiallylamine hydrochloride, N-hydroxyethyldiallylamine hydrobromide and N-acetohydrazide substituted diallylamine hydrochloride.

In the production of homopolymers and copolymers for use

in the method according to the present invention, the reaction can be started with a catalytic redox system. In this system, the catalyst is activated by means of a reducing agent which produces or gives free radicals without the use of heat. Commonly used reducing agents are sodium metabisulphite and potassium metabisulphite. Other reducing agents include water-soluble thiosulfates and bisulfites, hydrosulfites and reducing salts, such as the sulfate, of a metal capable of existing in more than one valence state, e.g. cobalt, iron, manganese and copper. A specific example of a sulfate is ferrous sulfate. The use of a redox initiator system has several advantages, and

the most important is that you get an efficient polymerization with lower temperatures. Common peroxide catalysts such as tertiary butyl hydroperoxide, potassium persulfate, hydrogen peroxide and ammonium persulfate can be used together with the above reducing agents or metal activators.

As mentioned above, the linear polymers of the diallylamines may contain different units of formula (I) and/or contain units of one or more other copolymerizable monomers. Commonly, comonomers will be another diallyl amine, a monoethylenically unsaturated compound containing a single vinyl or vinylidene group, or a sulfur dioxide, and which is present in an amount varying from 0 to 95 mol% of the polymer. The polymers of diallylamine are thus linear polymers where from 5-10% of the recurring units have formula (I) and from 0-95% of the recurring units are monomer units derived from (I) a vinyl or vinylidene monomer and/or (2) sulfur dioxide. Preferred copolymers include acrylic acid, methacrylic acid, methyl or other alkyl acrylates and methacrylates, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl ethers, such as alkyl vinyl ethers, vinyl ketones, such as methyl vinyl ketone and ethyl vinyl ketone, vinyl sulfonamide, sulfur dioxide or another diallylamine, such as this is defined according to formula (II) above.

Specific copolymers which can be reacted with an epihalohydrin include copolymers of N-methyldiallylamine and sulfur dioxide, copolymers of N-methyldiallylamine and diallylamine; copolymers of diallylamine and acrylamide; copolymers of diallylamine and acrylic acid; copolymers of N-methyldiallylamine and methacrylate; copolymers of diallylamine and acrylonitrile; copolymers of N-methyldiallylamine and vinyl acetate; copolymers of diallylamine and methyl vinyl ether; copolymers of N-methyldiallylamine and vinyl sulfonamide; copolymers of N-methyldiallylamine and methyl vinyl ketone; terpolymers of diallylamine, sulfur dioxide and acrylamide; as well as terpolymers of N-methyldiallylamine, acrylic acid and acrylamide.

The epihalohydrin reacted with the polymer of a diallylamine can be any epihalohydrin, e.g. epichlorohydrin, epibromohydrin, epifluorohydrin or epiiodohydrin, and is preferably epichlorohydrin. Usually the epihalo-genhydrin will be used in an amount varying from 0.5 to 1.5 moles and preferably from 1 to 1.5 moles per moles of secondary plus tertiary amine present in the polymer.

The poly(diallylamine)-epihalohydrin resin can be prepared by reacting a homopolymer or copolymer of a diallylamine-, as indicated above, with an epihalohydrin at temperatures from 30-80°C, preferably from 40-60°C, until the viscosity, measured on a solution containing from 20-30% solids at 25°C, has reached a range from A to E, preferably from approx. C to D on the Garner-Holdt scale. The reaction is preferably carried out in an aqueous solution to moderate the reaction, and at a pH from 7 to 9.5.

When the desired viscosity has been reached, sufficient water is added to adjust the solids content of the resin solution to approx. 15% or less, after which the product is cooled to room temperature.

The resin solution can be stabilized against gel formation by

adding to the aqueous solution sufficient amounts of a water-soluble acid (such as hydrochloric or sulfuric acid) to achieve and maintain a pH value of about 2. The resulting acid stabilized resin solution can be used as such in carrying out the present process or, if desired, reactivated prior to use by known methods. Such acid-stabilized resin solutions as well as methods for their reactivation are indicated and described in US-PS 3,833,531.

Before stabilization against gelation, the resin in solution, which is in its active and easily crosslinkable form, can be stated as follows:

When it is stabilized against gel formation using HC1, e.g. in (III) become (IV) where

X is halogen such as chlorine. The resin is reactivated by adding an aqueous solution of NaOH, then the compound with formula (IV) will be converted to the epoxide form as shown with formula (III).

The group

in the compound of formula (III) can be converted, if desired, to

(V) by adding

add sodium bicarbonate to the solution of the compound of formula (III) and heat the resulting solution to approx. 100°C for approx. 1.5 hours. In the form indicated by formula (V), the resin will not be cross-linked, nor can it be converted into a compound of formula (III). It is in a glycol form and is an inert cationic polymer.

All forms of the resin as indicated above,

can be used in the method according to the present invention and the expression poly(diallylamine)-epichalohydrin resin as used here and in the subsequent claims includes all resins where the epichalohydrin group is. in the form indicated in the formulas (III), (IV) and (V). The resin used in the present invention can thus be stated as follows:

-CH0CHCH0 , -CH-CHCH,, -CH~CHCH0 ..

0 OH Cl Oll OH

The following examples illustrate the invention.

Example 1.

A solution of 69.1 parts of N-methyldiallylamine and 197 parts of 20° Be hydrochloric acid in 111.7 parts of demineralized water was purged with nitrogen to remove air, and then treated with 0.55 parts of tertiary butyl hydroperoxide and a solution of 0 .0036 parts iron sulfate in 0.5 parts water. The resulting solution was set aside for polymerization at 60-69°C for 24 hours, whereby a polymer solution containing approx. 52.1% solids with an RSV of 0.22.

122 parts of the above solution was adjusted to pH 8.5 by adding 95 parts of 3.8% sodium hydroxide and then diluting it with 211 parts of water and combining with 60 parts of epichlorohydrin. The mixture was held at 45-55°C for 1.35 hours, until the Gardner-Holdt viscosity of a sample cooled to 25°C reached B+. The resulting solution was acidified with 25 parts of 20° Be hydrochloric acid and held at 60°C until the pH became constant at 2.0. The resulting resin solution had a solids content of 20.8%, and a Brookfield viscosity of 77 eps. (measured using a Brookfield model LVF viscometer, No. 1, spindle at 60 rpm with guard).

Example 2.

25 parts of a resin solution containing 9.58% solids prepared as indicated in Example 1 was combined with a solution of 1.62 parts 10N sodium hydroxide in 11.25 parts water and aged for 1/2 hour.

Example 3.

150 parts of a resin solution containing 20% solids prepared as indicated in Example 1 was diluted with 172.5 parts of water. To the solution was then added a solution of 7.2 parts of HaOH in 160 parts of water. The resulting solution was allowed to stand for 5 minutes and then added

10.5 parts NaHCO^. The solution was then heated to boiling under reflux for 1 1/2 hours and then cooled to room temperature. The resulting solution had a solids (modified resin) content of 9.2% and a Brookfield viscosity of 77 eps.. (measured as previously stated).

The adhesive accelerators can be used in combination with hydrophobic cellulose-reactive adhesives, such as ketene dimers, acid anhydrides and isocyanates. Such adhesives are well known in the industry and are usually used as aqueous emulsions.

With the term "emulsion" is understood either a dispersion of liquid in the liquid type or of a solid substance in the liquid type,..

Hydrophobic acid anhydrides which can be used as cellulosic reactive sizing agents for paper include (A) rosin anhydride (see US-PS 3,582,464); (B) anhydrides of the following formula:

where is a saturated or unsaturated hydrocarbon radical, and where the hydrocarbon radical is either a straight or branched alkyl radical, an aromatic substituted alkyl radical or an alkyl substituted aromatic radical as long as the hydrocarbon radical contains a total of from 14 to 36 carbon atoms; and (C) cyclic dicarboxylic acid anhydrides of the following formula

where R" represents a dimethyl or trimethylene radical and where R" 1 is a hydrocarbon radical with more than 7 carbon atoms selected from alkyl, alkenyl, aralkyl or aralkenyl. Substituted cyclic dicarboxylic acid anhydrides of the above formula (VIII) are substituted with succinic and glutaric anhydrides. In formula (VII) above, each of the groups may be the same or different.

Specific examples of anhydrides of formula (VII) are myristoyl anhydride, palmitoyl anhydride, oleoyl anhydride and stearoyl anhydride.

Specific examples of anhydrides of formula (VIII) are isooctadecenyl succinic anhydride, n-hexadecenyl succinic anhydride, dodecyl succinic anhydride, decenyl succinic anhydride, octenyl succinic anhydride and heptylglutaric anhydride.

Hydrophobic organic isocyanates are widely used as adhesives in the paper industry. The best results are obtained when the hydrocarbon chain in the isocyanates contains at least 12 carbon atoms, preferably from 14 to 36 carbon atoms. Such isocyanates include rosin isocyanate, dodecyl isocyanate, octadecyl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate, eicosyl isocyanate, docosyl isocyanate, 6-ethyl^decyl isocyanate , 6-phenyldecylisocyanate and polyisocyanates such as 1,18-octadecyl diisocyanate and 1,12-dodecyl diisocyanate,. and where a long-chain alkyl group serves two isocyanate radicals and gives the molecule hydrophobic properties as such.

Keten dimers are well known as cellulose-reactive adhesives, and they have the following formula:

where R2 is a hydrocarbon radical such as an alkyl with at least 8 carbon atoms, cycloalkyl with at least 6 carbon atoms, aryl, aralkyl and alkaryl. When naming ketene dimers-becomes

the radical "I^" followed by "ketene dimer". Thus, phenyl ketene dimers are the following: and benzyl ketene dimers are:

and decyl ketene dimer is [C^qH^-l-CH=C=0]. Examples of ketene dimers include octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, phenyl, benzyl beta-naphthyl and cyclohexyl ketene dimers, as well as ketene dimers prepared from montamic acid, naphthenic acid, A9,10-decylenic acid, A9,10- decylenic acid, α9,10-dodecylenic acid, palmitoleic acid, oleic acid, castor oleic acid, linoleic acid, linolenic acid and elostearic acid, as well as ketene dimers prepared from naturally occurring mixtures of fatty acids, e.g. the compounds found in coconut oil, babassu oil, palm kernel oil, palm oil, olive oil, peanut oil, rapeseed oil, beef tallow and whale blubber. Mixtures of any of the above mentioned fatty acids can also be used.

The following examples show the preparation of ketene dimer emulsions.

Example 4.

An emulsion of an alkyl ketenediene prepared from a mixture of palmitic acid and stearic acid was prepared by mixing 880 parts of water, 60 parts of cationic corn starch and 10 parts of sodium lignin sulfonate. The mixture was adjusted to a pH of about 3.5 with 98%" sulfuric acid. The resulting mixture was heated to 90-95°C for about 1 hour. Water was then added to the mixture in sufficient quantity to give a mixture of 1750 parts (total weight). About 240 parts of ketene dimer was then stirred into the mixture simultaneously with 2.4 parts of thiadiazine. The thiadiazine was used as a preservative. The resulting premix was homogenized at 65°C by passing through a homogenizer at a pressure of 280 kg/cm 2 . The homogenized product was diluted with water to a content of ketene dimer solids of approximately 6%.

Example 5.

Example 4 was repeated with the exception that the alkyl ketene dimer of oleic acid was used instead of the alkyl ketene dimer prepared from a mixture of palmitic acid and stearic acid.

Example 6.

Part of the emulsion from example 4 was diluted with water to a content of ketene dimer solids of approx. 0.10%.

Example 7.

Part of the emulsion from Example 5 was diluted with water to a solids content of 0.10%.

Example 8.

Products prepared as indicated in example 1 and example 4 were combined with the addition of water as needed, so that an aqueous adhesive consisting of 0.10% ketene dimer and 0.20% resin was obtained.

Example 9.

Products prepared as indicated in Example 1 and Example

4 was combined with the addition of water as needed, so that an aqueous adhesive consisting of 0.10% ketene dimer and 0.10% resin was obtained.

Example 10.

Products prepared as indicated in Example 2 and Example

4 was combined with the possible addition of water, so that an aqueous adhesive consisting of 0.10% ketene dimers and 0.10% acid-stabilized resin was obtained.

Example 11.

Products prepared as indicated in Example 3 and Example

4 was combined with any addition of water as needed, so that an aqueous adhesive consisting of 0.10% ketene dimer and 0.10% modified resin was obtained.

Example 12.

Products prepared as indicated in example 1 and example 5 were combined with any addition of water, so that an aqueous adhesive consisting of 0.10% ketene dimer and 0.10% resin was obtained.

The above-mentioned adhesives were applied to the surface of a paper sheet of 17 kg/270 m 2. The paper was produced from a pulp mixture consisting of 50% hardwood and 50% softwood, in a small paper mill. Each sizing agent was adjusted to pH 7 before application to the sheet in a horizontal sizing press. The glue press had a speed of 12 m/min. and the wet absorption was up to 70%. The absorption of the ketene dimer sizing agent was the same in all trials. The bonded sheets were dried at 94°C for 20 seconds in a laboratory tumble drier to a moisture content of 4%. The gluing was measured by a Hercules glue test with sample solution no. 2 to the specified reflection. Data out of the machine was obtained during a two-minute drying time and the natural and aged data after at least 3 days of storage at room temperature. It is well known that ketene dimer adhesives develop all their adhesive properties in paper within 3 days. After this time, the properties with regard to the gluing of paper will essentially be the same.

The results are set out in Table I below.

The following examples show the improvement in adhesive strength out of the machine when adhesives according to the present invention were used for internal gluing.

Hand sheets of the same thickness as mentioned above (17 kg/270 m 2 ) were produced in a Noble and Wood hand sheet apparatus using a pulp consisting of 20% newsprint pulp, 35% Rayonier bleached softwood pulp and 35% Weyerhauser bleached kraft pulp. wood pulp. The sheets were dried from 45-50 seconds at 102°C. The glue-accelerating resin in aqueous solution was added to the aforementioned portion when the mass had a consistency of approx. 0.275% and then stirred for 15 seconds, after which the ketene dimer glue emulsion was added, after which a new stirring was carried out for approx. 15 seconds. The mass was then diluted with water, so that a consistency of approx. 0.025% in the bucket box before the production of the sheets took place. The amounts of accelerator resin used and a ketene dimer used are set forth in Table II below, and are based on the dry weight of the pulp.

The test results are set out in Table II below.

In Examples 13, 14, 15 and 16, the accelerator resin was

and the adhesive added separately. It is of course understood that they can be mixed in advance, so that you get an adhesive, e.g. as with surface gluing., before the agent is added to the pulp suspension, after which glued sheets can be produced from the treated pulp.

Example 17.

An aqueous emulsion of octadecylisocyanate (stearyl isycyanate) adhesive was used for an internal gluing of hair sheets, using a mass consisting of 50% l.wood pulp and 50% barvéd pulp, as well as 10% clay and 10% calcium carbonate as fillers. Cationic starch ("Stalok 400"), 35% based on the dry weight of the pulp, was added as absorbent for the f yilstof f. The amount of octadecylisocyanate used as a sizing agent was 0.2% based on the dry weight of the fibers.

Example 18.

Example 17 was repeated with the exception that the resin which was produced in accordance with example 1, in aqueous solution, was also added to the mass before producing the sheets in an amount corresponding to 0.125% of the dry weight of the mass. The test results are set out in Table III below.

Claims (8)

1. Process for the production of glued paper using an aqueous emulsion of a hydrophobic cellulose-reactive adhesive selected from the group consisting of ketene dimers, acid anhydrides and organic isocyanates, using in combination with the adhesive a poly(diallylamine)-epihalohydrin resin, characterized by that the poly(diallylamine)-epihalohydrin resin is added in a sufficient quantity to increase the gluing effect of the sizing agent, as the paper comes out of the machine. 2. Method according to claim 1, characterized in that a ketene dimer is used as adhesive and a poly(N-methyldiallylamine) epichlorohydrin resin is used as adhesive accelerator. 3. Method according to claim 1, characterized in that an acid anhydride is used as adhesive and a poly(N-methyldiallylamine) epichlorohydrin resin is used as adhesive accelerator. 4. Method according to claim 1, characterized in that an organic isocyanate is used as adhesive and a poly(-N-methyldiallylamine) epichlorohydrin resin is used as an adhesive accelerator. 5. Adhesive for cellulose fibers consisting essentially of an aqueous emulsion of a hydrophobic cellulose-reactive adhesive selected from ketene dimers, acid anhydrides and organic isocyanates, characterized in that it contains an adhesive accelerator in the form of a poly(diallylamine)-epihalohydrin resin which is present in a sufficient amount to increase the adhesive properties of the sizing agent on the paper as it comes out of the paper machine. 6. Adhesive according to claim 5, characterized in that the adhesive is a ketene dimer and the adhesive accelerator is a poly(N-methyldiallylamine) epichlorohydrin resin. 7. Adhesive according to claim 5, characterized in that the adhesive is an acid anhydride and the adhesive accelerator is a poly(N-methyldiallylamine) epichlorohydrin resin. 8. Adhesive according to claim 5, characterized in that the adhesive is an organic isocyanate and the adhesive accelerator is a poly(N-methyldiallylamine) epichlorohydrin resin.