CA1238324A - Process for sizing paper in anionic hydrophobic sizing agents and cationic retention aids - Google Patents

Abstract

1-14067/+
A process for sizing paper with anionic hydrophobic sizing agents and cationic retention aids Abstract Anionic sizing agents which are novel reaction pro-ducts of hydrophobic ketene dimers and diamines or oligo-amines are particularly suitable for use, together with commercially available cationic retention aids, in a process for sizing paper or board.

Description

~2383Z~

1-14067/~

A process for sizing paper with anionic hydrophobic sizing agents and cationic retention aids It is the object of the present invention to provide the paper manufacturer with readily accessible and simply obtainable sizing agents which, combined with conventional cationic retention aids into a novel combination, are capable of giving efficient sizing in the manufacture of paper from dispersions of the fibres.
This object is achieved in a novel manner by using, 1~ in the manufacture of paper in the presence of polymeric cationic retention aids, sizing agents which are compounds which have at least two~ preferably at least four, long-chain hydrophobic substituents and at least one anionic or acidic group which can be in salt form.
The present invention thus provides a process for sizing paper or cardboard, wich comprises adding in any order or simultaneously, to aqueous dispersions of the fibres which can, if desired, also contain filler, at least (A) an an;onic hydrophobic sizing agent which can be obtained from ta) ketene dimers and (b) diamines or oligoamines, and (B) a polymeric cationic retention aid.
The invention also relates to - the aqueous compositions for carrying out the paper-sizing process, which, ;f the siz;ng agent (A) and the retention aid (B) are added separately in any order to the dispersion of the fibres, contain, in addition to optional customary additives, the s;zing agent (A) - which can be at least partly in the form of salts - alone, or, if the sizing agent ~F~

~2383;~4 tA) and the retention aid (B) are added simultaneously to the dispersion of the fibres, not only the sizing agent tA) but also the retention aid (B) in addition to optional customary additives, - the paper or cardboard sized by the process according to the invention and - the use of the sizing agent (A) of the specified type for sizing paper or board.
The specified sizing agent (A) are novel compounds.

These sizing agents per se and the process for their pre-paration are therefore also part of the subject-matter of the present invention.
The sizing agents (A) which are used in accordance with the ;nvention and which can be obtained from the compon-ents (a) and (b), have as an essentiaL feature 1 to 6, pre~er-ably 2 to 6, potentially anion;c groups which are generally ;n the form of ac;d;c CH groups. The ab;lity of the poten-tially anionic substituents to form anions in an aqueous medium is a further essential characteristic of the sizing agent. The formation of anions takes place at the pH the dispersion of the fibres usually has in the manufacture of paper. Under said conditions the cationic retention aids (B) are also capable of ionising to form cations. The ability of the sizing agents and retention aids to form anions and cat;ons respect;vely under the cond;t;ons of paper manu-facture can also be referred to as an;on-active and cation-act;ve respect;vely. The an;onic sizing agents and the cationic retent;on aids can therefore also be referred to as an;on-active sizing agents and cation-active retention aids.
The sizing agents (A), which can be obtained from the components (a) and tb), have as a further characteris;ng feature 2 to 12, preferably 4 to 12, hydrophobic substituents which solely cons;st of carbon and hydrogen and have at least 5, preferably 8 to 22, carbon atoms, for example C5-C12-cyclo-alkyl or C6-C1~-aryl, -alkaryl or -aralkyl rad;cals.
Preferred hydrophob;c substituents, however, are alkyl or alkenyl radicals wh;ch generally der;ve from fatty ac;ds 123~33~4 having at least 6, preferably 8 to 2Z, carbon atoms. The way these hydrophobic substituents are linked to each other forms another characteristic of the (A) sizing agents,for the link-ing members with which at least two of the hydrophobic groups S are bonded to each other preferably have 2 to 18 carbon atoms and at least 2 hetero atoms each, preferably at least 2 nitro-gen atoms, in the main chain. Linking members which each have

2 to 12 carbon and two nitrogen atoms are preferred. Depending on the number of hydrophobic substituents, the sizing agents contain 1 to 5 linking members of the specified type.
Preferably used (A) sizing agents of the specified type have molecular weights of about 1,0nO to about 4,000.
The component ta), from which the sizing agent (A) can be obtained, is, for example, a dimer of the ketenes of the formulae (1) R1-CH=C=0 and (2) R1'-CH=~=0 in which R1 and R1' are identical or different and each is a hydrophobic substituent having at least 5 carbon atoms, provided that at least one of the radicals R1 and R1' has at least 8 carbon atoms.
Preferred d;mers are of ketenes of the formulae

(3) Rz-CH=C=O and

(4) R2'-CH=C=0 ;n which Rz and R2' are identical or different and each is alkyl or alkenyl having 5 to 22 carbon atoms, cycloalkyl having 5 to 12 carbon atoms or aryl, alkaryl or aralkyl having 6 to 10 carbon atoms, prov;ded that at least one of the radicals R2 and R2' has at least 8 carbon atoms.
Dimers to the fore of interest are of ketenes of the formulae

(5) R3-CH=C=0 and

(6) R3'-CH=C=0 where both of the ketenes derive from an unsaturated or saturated fatty acid having at least 6, preferably 8 to 22, carbon atoms and R3 and R3' are identical or different, provided that at least one of the radicals R3 and R3' derives ~2~ 12~

from a fatty acid which has at least 8 carbon atoms.
In the definitions of R2 and R2' in the formulae (3) and (4), representatives of C5-C1z-cycloalkyl are, for example, cyclopentyl, cyclododecyl and especially cyclohexyl, and representatives of C6-c1o-aryl~ alkaryl or aralkyl are for example naphthyl, tolyl, xylyl, phenylethyl and especially ~naphthyl, benzyl and phenyl.
The unsaturated or saturated C6-C2z, preferably C8-C22, fatty acids from which the ketenes of the formulae t5) and (6~ derive is for example caproic, preferably caprylic, capric and arachidic acid, in particular lauric, myristic, palmitic, stearic and behenic acid or myristoleic, palmitoleic, elaeostearic, or clupanodonic acid, in particular oleic, elaid;c, erucic, linoleic and linolenic acid. Of these, Lauric acid, paLmitic acid, stearic acid, oLeic acid and behenic acid are of particular importance. Stearic acid is to the fore of interest and is used especially combined with the other fatty acids mentioned last. Ketenes which derive from technical mixtures of said saturated and/or un-saturated fatty acids are particularly preferred.
Dimers of ketenes of the formulae(7) R4-CH=C=0 and (8) R4'-CH=C=û
where the two ketenes derive from lauric, palmitic, stearic, ole;c or behenic ac;d or mixtures thereof and R4 and R4' are identical or different, are thus to the fore of interest.
Ketene dimers of the specified type are known per se and have been described, for example, in U.S~ Patent 4,317,756.
Their preparation, for example from the corresponding acid halides, in particular fatty acid chlorides, and strong tertiary bases, in particular trialkylamines, has been dis-closed in, for example, U.S. Patent 2,383,863.
Said U.SO Patent 4,317,756 gives the ketene dimers in which R1 and R1' in the formulae (1) and (2) are iden-tical by means of the formula ~1.1) ~R1-cH=c=o]2 Z~
.

;n which R1 ;s as defined above~ However, the ketene dimers can also be cyclic and have the formula 1~ -CH=C--CH-R ' (1.2~
O--C=O

in which R1 and R1' are identical or different and are as defined above.
The component (b~, from which the sizing agent (A~
can be obtained, can be an aliphatic, cycloaliphatic, aromatic, araliphatic or heterocyclic diamine or oligoamine having 2 to 6 nitrogen atoms and 2 to 36 carbon atoms. The oligoamines are in particular aliphatic amines, in particular polyalkylenepolyamines having at most 6 nitrogen atoms and 2 or 3 carbon atoms in each alkylene bridge member. The di-amines, however~ can have between the two nitrogen atoms not only aromatic or araliphatic bridge members, preferably having 6 to 16 carbon atoms, or heterocyclic bridge members, preferably of the piperazine ser;es, but also aliphatic br;dge members hav;ng preferably 2 to 8 carbon atoms or cycloaliphatic bridge members having preferably 5 to 12 carbon atoms.
Preferred diamines or oligoamines accordingly have the formula (9) D1-NH-A1-NH2 in which A1 is alkylene, hydroxyalkylene, alkenylene or cycloalkylene having at most 12 carbon atoms, an alkaryl or aryl radical of one of the formulae (9.1) ~(CH2)n~ (CH2)n2_ .=.
or (9 2) ~CH2)n3~ ; . r-.~(CH2)n ~2~3,24 or naphthylene, a heterocyclic radical of ~he formula (9 3) -E~ -El'-or, in the case of oligoamines, an aliphatic radical of the formula (9 4) (E1 NH)m E1 D1 is hydrogen or an alkyl or alkenyl radical which derives from fatty acids having 8 to 22 carbon atoms, E1 and E1' each are ethylene or n-propylene, n1, n2, n3 and n4 each are 1, 2 or 3, and m is an integer from 1 to 4~
If A1 is alkylene, hydroxyalkylene or alkenylene, the bridge members can be branched as weil as straight-chain.
Alkenylene rad;cals generally have 3 to 8 carbon atoms and 3 or 2 double bonds or preferably only one double bond.
Alkylene ;s preferred to alkenylene and generally has 2 to 9, in part;cular 2 to 6, carbon atoms. Alkylene rad;cals can be unsubstituted or be preferably subst;tuted by at most 2 hydroxyl groups, in particular only one hydroxyl group. Such hydroxyalkylene rad;cals are generally straight-cha;n. Rep-resentatives of cycloalkylene radicals are cyclodecylene, cyclododecylene and, espec;ally, cyclopentylene and, ;n par~i-cular, cyclohexylene. If D1 ;5 an alkyl or alkenyl rad;cal, it preferably der;ves from the abovement;oned C6-C22, prefer-ably C8-C22, fatty ac;ds. D1 ;5 preferably an alkyl or alkenyl rad;cal only ;f A1 ;s alkylene. Ethylene is the preferred definition of E1 and E1'. Preferably n1 and n2 each are 1 or 2 and n3 and n4 each are 1~ Preferred representatives of the formula (~.1) are toluylene and especially xylylene and phenylene, and the formula t9~2) pre-ferably represents diphenylene ether.
D;amines or oligoam;nes wh;ch are to the fore of interest thus have the formula t10) D2-NH-A2-NH2 ;n which A2 ;s unsubstituted straight-chain or branched ~2;3~3;~

alkylene or hydroxyl-substituted straight-chain alkylene having 2 to 9 carbon atoms, cyclopentylene, cyclohexylene, phenylene, toluylene, xylylene, diphenylene ether or (10.1) (cH2-c~2-NH~m-cH2-cH2-o D2 is hydrogen or~ if A2 is alkylene~ an alkyl or alkenyl radical which derives from a fatty acid having 8 to 22 carbon atoms, and m is an integer from 1 to 4, and in particular the formula (11) D3-NH-A3-N~2 in which A3 is unsubstituted or straight-chain alkylene which is substituted by at most one methyl or hydroxyl radical and has a total of 2 to 6 carbon atoms, cyclohexylene, phenylene, diphenylene ether, xylylene or the radical of the formula (1û.1), D3 is hydrogen or, ;f A3 is alkylene, an alkyl or alkenyl radical wh;ch derives from lauric, palm;tic, stearic, oleic or behenic acid or mixtures thereof.
The novel sizing agent (A) according to the inven-tion can be obtained from the ketene dimers defined above and used as component (a) and the diamines or oligoamines defined above and used as component (b). Provided that the component (a) used is dimers of the ketenes of the formulae (1) and (2) or ketene dimers of the formula (1.1) or (1.2) and the com-ponent (b) used is diamines or oligoamines of the formula (9), the (A) sizing agents, or salts thereof, have one of the probable formulae Dl-N------Ao~~~NH D -N------(El------~) ---El'---NH
CO CO ro CO CO
(12) 1 1 or (13) CH-Rl' Cil-Rl' CH-R ' CH-R ' CH-R
CO CO CO CO CO
C~2-Rl CH2-R, 2 1 CH2 1 CH -B

of which formula (12) applies if diamines are used as start-ing components (a) and formula (13) applies if oligoamines are used as starting component (a), and, in the formulae (12) ~2:~,3~4 and (13), Ao is alkylene, hydroxyalkylene, alkenylene or cycloalkylene having at most 12 carbon atoms, an alkaryl or aryl radical of the formulae (9.1) or (9.2) or naphthylene, or a heterocyclic radical of the formula (9.3), E1 and E1, S each are ethylene or n-propylene, D1 is hydrogen or an alkyl or alkenyl radical which derives from fatty acids having 8 to 12 carbon atoms, and R1 and R1' are identical or different and each denotes a hydrophobic subs-tituent having at least 5 carbon atoms, provided that at least one of the radicals R1 and R1' has at least 8 carbon atoms. If the siz;ng agents of the formula ~12) or (13) are in the form of salts, R1 l the hydrogen atom in the -C0-CH-C0- groupings are at least partly replaced by the cation of the corresponding salt.
Reaction products of the formuLa (12) or (13) ar~
prepared by reacting with one another ta) a dimer of a ketene of the formulae (1) or (2) with (b) a diamine of the formula (14) D1-NH-Ao~NH2 or an oligoamine of the formula (15) D1-NH-(E1-NH)m-E1l-NH2 which Ao~ D1, E1, E1' and m are as defined above.
In this method of preparation, 1 to 1.1 equivalents, in particular 1.0 equivalent, per amino group of component ~b) are preferably used per mol of component (a), and the reaction is generally carried out in the melt or preferably in at least one organic solvent, i.e. in a single solvent or in a solvent mixture, at preferred temperatures of about 10 to about 140C.
The solvents used must be inert not only to each of the starting components (a) and (b) but also to the end product, i.e. the reaction products of (a) and (b). Examples of possible solvents are halogenated or unhalogenated hydro-carbons which have a boiling point of at most 14ûC, prefer-ably between about 8û and about 140C, such as benzene, especially toluene, chlorobenzene, o-, m- and p-xylene, a technical xylene mixture or even mixtures of said hydrocarbons~

9 _ However, lower-boiling solvents are preferred, for example preferably halogenated hydrocarbons which boil at about 40 to about 80C, for example dichloroethane, carbon tetra-chloride or, especially, chloroform. It is especially advan-tageous to carry out the reaction at the reflux temperatureof whichever solvent of the specif;ed type is used.
Before they are used as component (A) in the paper-siz;ng process according to the invention, the sizing agents need generally not be purified and recrystallised after they have been prepared, but can, as a rule, be used directly.
Especially if the sizing agent (A) and the retention aid (B) are added separately (in any order) to the disper-sion of the fibres ;n the process according to the ;nvention for sizing paper or board it ;s advantageous to use some of the sizing agent in sa~t form. If desired, such salts can be obtained by adding, when the reaction between the compon-ents (a) and (b) has ended, to the reaction products obtained inter alia an alkylamine or alkanolamine having a total of at most 6 carbon atoms, for example trimethylamine, triethyl-amine, monoethanolamine or d;ethanolamine, especially byadding ammonia or an alkali metal hydroxide, for example potassium hydroxide or especially sodium hydroxide, and con-verting the reaction products obtained, if desired at least partly, into the corresponding salts, as a rule ;n an aqueous medium at room temperature (about 15 to about 25C). It is advantageous to use an alkali metal hydrox;de, for example potass;um hydroxide or, especiaLly, sodium hydroxide, or in particular ammonia, generally in the form of their dilute, approximately 1 to 10 per cent by weight, aqueous solution.
It is generally advantageous to use at most 2 mol, especi-ally at most 1 mol, preferably 0.1 to 0.9, in part;cular 0.1 to 0.7, mol of ammon;a or alkal; metal hydrox;de per grouping of the formula -~H- present in the reaction products of the formula (11) or (12). The reaction products thus present in salt form have the formula (11) or (12) ;n which at least some of the acidic groupings are converted ;nto the corresponding -~- anions whose negative charge~3 is ~X38329~

neutralised by the corresponding amine, ammonium or alkali metal cations.
The paper-sizing process according to the invention is always carried out with, in addition to the anionic or acidic sizing agent (A) which is described above and which is novel per se, a polymeric cationic retention aid (B) which generally has a molecular weight of at least 1,000, especi-ally at least about 2,500, preferab~y about 2,000 to about 2,000,000, in particular about 5,000 to about 2,000,000.
~etention aids having molecular weights within the range from 10,~00 to 100,000 are particularly preferred. In prin-ciple, any commercially available retention aid can be used in the process according to the invention.
Examples of conventional retention ai~s (B) which are particuLarLy suitable for use, together with the sizing agent (A), in the paper-sizing process according to the invention are polyalkyleneimines, epihalogenohydrin adducts of reaction products of polyalkylenepolyamines and of ali-phatic dicarboxylic acids or of reaction products of poly-alkylenepolyamines, of dicyanodiamide and free or alkanol-esterified organic dicarboxylic acids, reaction products of dicyanGdiamide, of formaldehyde, of ammonium salts of strong inorganic acids and of alkylenediamines or polyalkylenepoly-amines, cationically modif;ed starches or carbohydrates of carob bean or guar bean flour, copolymers based on poly-amide-amines and reaction products of epihalogenohydr;ns and of polymerised diallylamines.
Preferred epichlorohydrin adducts of reaction pro-ducts of polyalkylenepolyamines and aliphatic dicarboxylic acids are described, for example, in British Patent 865,727, epichlorohydrin adducts of reaction products of dicyanodi-amide and diethylenetriamine or triethylenetetramine, for example, in German Offenlegungsschrift 2,710,061 and in British Patent 1,125,486, epichlorohydrin adducts of reaction products of diethylenetriamine, dicyanodiamide and free or preferably lower-alkanol-esterified dicarboxylic acids, in particular dimethyl adipate, for example, in British Patent ~324 1,125,486, and reaction products of dicyanodiamide, formalde-hyde, ammonium salts of strong organic acids and of ethylene-diamine or triethylenetetramine, for example, in U.S. Patent 3,491,064. Preferred cationically modified starches and carbohydrates from carob bean and guar bean flour are alkyl-ene oxide adducts of these starches or carbohydrates, the alkylene oxide used having 2 or 3 carbon atoms in the alkyl-ene radical and quaternary ammonium groups~ Copolymers based on polyamide-amines have molecular weights of 103 to 105, preferably 103 to 104, and can be obtained from, for example, aliphatic saturated dicarboxylic acids having 2 to 10, preferably 3 to 6, carbon atoms, in particular adipic acid, and polyalkylenepolyamines, for example polypropylene polyamine and polyethylenepolyamine, in particular dimethyl-aminohydroxypropyldiethyLenetriamine. They are described,for example, in the CTFA Cosmetic Ingredient Dictionary, 3rd edition 1902, of the Cosmetic Toiletry and Fragrance Asso-ciation. Reaction products of epihalogenohydrins and poly-merised diallylamines preferably have molecular weights of 1,000 to 2,000 and are described, for example, in U~S. Patents 3,700,623 and 4,279,794.
Examples of retention aids (B) which are to the fore of interest for use together with siz,ing agents (A) in the paper-sizing process according to the invention are a corn or potato starch which has been modified with a propylene oxide conta;n;ng quaternary ammonium groups and whose 25%
suspension in dist;lled water at 20C has a pH of 4.2 -4.6, a polyethyleneimine which has a molecular weight of 10,000 to 100,000, an epichlorohydrin adduct of a reaction product of triethylenetetramine and dicyanodiamide, an epi-chlorohydrin adduct of a reaction product of diethylenetri-amine, dicyanodiamide and d;methyl adipate, a reaction pro-duct of d;cyanodiamide, formaldehyde, ammonium chloride and ethylenediamine, an epichlorohydrin adduct of a poly-N-methyldiallylamine and a copolymer of adipic acid anddimethylaminohydroxypropyldiethylenetriamine.
In the process generally 0.02 to 3, preferably 0.1 ~23~3~4 to 3, in particular O.Z to 0.~, per cent by weight of the sizing agent (A) and 0.02 to 5, preferably 0.1 to 3, in par-ticular 0.2 to 0O4~ per cent by weight of the retention aid (B~, each based on dry substance in ~A) and (~) and on the solids content of the dispersion of the fibres, are used.
0.02 to less than 0~1 per cent by weight of the sizing agent (A) and of the retention aid (B) are only sufficient for size press control, which cannot be detected in conventional sizing tests (cf., for example, the article "ControL and understanding of si~e press pickup" by D.R. Dill in the jour-nal TAPPI (Proceedings of the Technical Association of the Pulp and Paper Industry), Volume 57, No. 1, of January 1974, pages 97 to 100).
The dispersion of the fibres, to which sizing a~ents (A) and the retention aids (B) are added, generally has a solids content of 0.1 to 5, preferably 0.3 to 3, in particular û.3 to 1, per cent by weight and a Schopper-Riegler freeness of 20 to 60, preferably 20 to 45, in particular 25 to 35.
It generally contains pulp, in particular pulp from conifers, that is softwood, for example pinewood, or from hardwood, i.e. deciduous wood, for example beechwood, which is prepared by conventional methods, for example the sulfite or, especially, the sulfate methods. The dispersion of the fibres can, if desired, also contain mechanical wood pulp. Even alum-containing waste paper can be present in the dispersion of the fibres. It is even possible to use dispersions of cellulose fibres which are prepared by the CMP or CTMP processes (Chemimechanical and chemithermomechanical pulping processes, cf., for example, the article "Developments in refiner mechanical pulping" by S.A. Collicutt et al. in TAPPI, Volume 64, No. 6 of June 1981, pages 57 to 61).
The dispersion of the fibres can also contain organic or mineral fillers. Possible organic fillers are, inter alia, synthetic pigments, for example polycondensation pro-ducts of urea or melamine and formaldehyde, which have large .specific surface areas, which are present in highly dispersedform and have been described, inter alia, in Pritish Patents ~23~33%~

1,043,937 and 1,318,244, and possible mineral fillers are, inter alia, montmorillonite, titanium dioxide, calcium sul-fate and, especially, talc, kaolin and/or chalk Scalcium car-bonate). The dispersion of the fibres generally CGntains 0 to 40, preferably 5 to 25, in particular 15 to 20~ per cent by weight, based on the solids content of the dispersion of the fibres, of dry substance of the fillers of the specified type.
The pH of the dispersion of the fibres can be within a wide range, for example between 3.5 and about 10.
Adding calcium carbonate, for example, gives alkaline dispersions of the fibres, which have a pH of about 7 to about 9, preferably 7.5 to 8.5. Acid dispersions of the fibres, ~hich have a pH of 3.5 to 7, preferably 5 to 7, in particular 5 to 6, can be obtained in the absence of caLcium carbonate by adding acids, for example sulfuric or formic acid or especially, for example, latent acidic sulfates, such as aluminium sulfate (alum).
D;spersions of the fibres wh;ch are free of filler can be within a wide pH range, for example from 3.5 to 10.
Preferred dispersions of the fibres have a pH of about 7 to about 9, if appropriate as the result of adding chalk, and they are advantageous in that they prevent possible corrosion of the sensitive paper machines.
The dispersion of the fibres can also contain addi-tives, for example starch or its degradation products, whichincrease the fibre-fibre or fibre-filler bond.
Even high molecular weight polymers of the acrylic acid series, for example polyacrylamides having molecular weights of above 1,000,000, can be added to the dispersions of the fibres as an aid for retaining very fine cellulose particles, very low levels of about 0.005 to 0.02 per cent by weight, based on dry substance of the high molecular weight polymer and the solids content of the dispersion of the fibres, being sufficient.
The dispersion of the fibres is processed in the pro-cess according to the invention into paper or board in a manner known per se, namely on sheet formers or, preferably, continuously on paper machines of convent;onal design.
Drying at about 100 to 140C for about 0.5 to 10 minutes gives papers having a variable weight per unit area, for example from 50 to 200 g/m2.
As mentioned above, the aqueous composition for carrying out the paper-sizing process according to the inven-tion contains, in addition to optional customary additives, the sizing agent (A) if the sizing agent (A) and the reten-tion aid (B) are added separately to the dispersion of the fibres. In this case, the formulation preferably contains some of the s;zing agent in the form of its salts (obtained by using, for example, ammonia, an alkylamine, an alkanol-amine or an alkali metal hydroxide of the specified type in the abovementioned ratios). These compositions generally contain 5 to 30, preferably 5 to 20, per cent by weight of dry substance of the sizing agent which is partly in salt form, based on the weight of the aqueous composition.
If, however, the sizing agent (A) and the retention aid (B) are added simultaneously to the dispersion of the fibres, the aqueous composition, in addition to the optional customary additives, contains (A) 2 to 40, preferably 5 to 30, in particular 5 to 10, per cent by weight of sizing agent (calculated as dry substance), based on the weight of the aqueous composition, and Z5 (B) 0.1 to 20, preferably 0.5 to 10, in particular 3 to 8, per cent by weight of retention aid (calculated as dry sub-stance), based on the aqueous composition.
The aqueous compositions of the specified type can, if desired, also conta;n, as customary additives, surface-active compounds, for example dispersants or also emulsifiersand/or water-soluble organic solvents. Possible dispersants and emulsifiers are, for example, conventional ligninsulfon-ates, ethylene oxide adducts of alkylphenols, fatty amines, fatty alcohols or fatty acids, fatty acid esters of polyhydric alcohoLs, substituted benzimidazoles or condensation pro-ducts of aromatic sulfonic acids and formaldehyde. Other surface-act;ve compounds are preferably anionic surfactants, ~23~i3Z4 in particular sulfate surfactants, for example diethanolamine lauryl sulfate or ethoxylated lauryl sulfates. Possible water-soluble organic solvents are aliphatic ethers having 1 to 10 carbon atoms, for example dioxane, methylene glycol n-S butyl ether or diethylene glyccl monobutyl ether, or alcoholshaving 1 to 4 carbon atoms, for example isopropanol, ethanol or methanol.
The compositions are prepared in a conventional manner, namely by stirring the sizing agent (A) together with the retention aid (B) or the sizing agent (A), for example partly in the form of its salt, by itself, either in a molten state or preferably in a solid state, in particular in pul-verulent form, generally 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 pulverulent form) at at most 90C, preferably at about 5D to 85C in the case of emulsions, in particular at about 15 to 25C in the case of d;spers;ons, to obta;n stable homogeneous emulsions or preferably dispersions. Since the sizing agents together w;th the retention aids or the sizing agents partly in salt form are generally self-dispersing or self-emulsifying, the use of dispersants or emulsifiers is generally not necessary. This also applies to the optional addition of solvents and/or surfactants, which are only used if the dispersions or emulsions have an insufficiently long shelflife.
It may be mentioned as an advantage of the process according to the invention that var;ous dispersions of the f;bres can be processed with relatively small amounts of sizing agent and retention aid in a simple manner into paper which has good sizing properties (ink flotation period and especially Cobb water absorption). The paper sized by the process of the invention has good mechanical properties, i.e.
good strength, in particular good tear strength. Good re-produc;b;lity of the process is ensured. In particular,d;spersions of the f;bres which contain mechanical wood pulp or waste paper can be processed. Also, the compatibility of the sizing agent used in the process according to the inven-tion with a very wide variety of fillers and also their addi-tives, for example kaolin or alums in the acid range of dis-persions of the fibres, is advanta~eous~ The sizing agents S also have excellent compatibility with fluorescent brighteners.
Furthermore, the whiteness of the sized paper is not signi-ficantly affected by the sizing and can, in certain circum-stances, even be improved. An especially great advantage is the surprisingly long shelflife of the sizing agent disper-sions of the specified type. This advantageous stabilityapplies not only to dispersions of sizing agents (A) by them-selves but also to dispersions of mixtures of sizing agents (A) and retention aids (s). It is, in particular, sig-nificantly better for dispersions of reaction products of the components (a) and (b) as ~A) sizing agents or m;xtures thereof with (B) retention aids than for dispersions of com-ponent (a) by itself or mixtures thereof w;th (B) retent;on a;ds.
The parts and percentages g;ven in the follo~ing preparation methods and illustrative embodiments are by weight.
Preparat;on Examples Example 1: 75 parts (0.15 mol) of the dimer of the ketenes of the formulae (16) CH3 (CH2)13 CH C 0 and (17) CH3 (CH2)15 CH=C=0 are dissolved in 300 parts of chloroform. 5.2 parts ~0.05 mol) of diethylenetriamine are added to the ketene dimer solu-tion in the course of 5 m;nutes, the reflux temperature of the react;on m;xture of about 62C comes about by ;tself.
The react;on m;xture ;s then held at th;s temperature for 2.5 hours. Remov;ng the chloroform under rèduced pressure g;ves, ;n the form of a d;st;llat;on residue, 80.2 parts (100~ of theory) of the crude react;on product of the formula ~;~3832~

(18) NH - CH2 - C~2 - N - CH2 - CH2 - NH
CO CO CO

I ( 2)q 3 1 ( 2)q 3 1 ( 2)q 3 CO CO CO

(CH2) ~-CH3 (CH2)q'-cH3 (CH2) ,-CH3 q = 13 and q' = 16 or q = 14 and q' = 15 For analytical purposes the crude reaction product is recrystallised from ethanol. The recrystallised product is S in the form of a crystalline colourless powder. Infrared spectroscopy and liquid chromatography show it to be free of unconverted ketene dimer.
Melting po;nt: 70-75C.
Elemental analysis:
10 calculated C 78.70X H 12.77% N 2.60X 0 5.93X
found C 78.5% H 12.6% N 2.7% 0 6.2%~
Example 2: Example 1 is repeated, except that 51 parts ~0.1 mol) of the dimer of the ketenes of the formulae (16) and (17) and 3.6 parts (0.025 mol) of triethylenetetramine are used, afford;ng 54.6 parts t100X of theory) of the crude reaction product of the formula (19) 1 2 2 =N - CH - CH - - NH

CO CO CO

~ ( 2)q 3 I ( 2)q 3 I ( 2)q 3 CO CO CO
(CH2)ql~CH3 (CH2)ql~CH3 2(CH2) ' CH3 q and q' as defined ;n formula (18).
The recrystallised product is likewise in the form of a crystalline colourless powder which is free of unconverted ketene dimer.
Melting point: 56 - 61C

3Z~

Elemental analysis:
calculated C 78.75% H 12.75% N 2.59% 0 5.91%
found C 79.0% H 12.5% N 2u7% 0 5.8%.
Example 3: Example 1 is repeated, except that 35.4 parts (0.07 mol) of the dimer of the ketenes of the formulae (16~
and (17) and 2.7 parts (0.014 mol) of tetraethylenepentamine are used, affording 38.1 parts (100% of theory) of the crude reaction product of the formula (20) NH CH2 CH2 1 2 2 - NH
CO CO CO
I ( 2)q 3 I ( 2)q 3 I ( 2)q 3 CO CO ~0 2 q 3 _ 2 q 3 _ (CH2)q'-cH3 q and q' as defined in formula (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the form of a colourless powder. It is like~ise free of uncon-verted ketene dimer.
15 Melting po;nt: 49 - 55C
Elemental analysis:
calculated C 78.78% H 12.74% N 2.58% 0 5.90%
found C 78.~% H 12.6% N 2.9% 0 6.2%.
Example 4: Example 1 is repeated, except that 35.4 parts (0.07 mol) of the dimer of the ketenes of the formulae (16) and (17) and 2.8 parts (0.012 mol) of pentaethylenehexamine are used, affording 38.2 parts (100% of theory) of the crude reaction product of the formula ~23l3324 ( 2 1 ) NH - CH2 - CH2 - = N - CH - CH - - N~
CO CO CO
Cl (CH2)q CH3 CIH (CH2~q CH3 I (CH2)q CH3 CO CO CO

2 q 3 _ 2 q' 3 _ (CH2)ql~CH3 q and q' as def;ned ;n formula (18).
The crude product is recrystallised from acetone for analyt;cal purposes. The recrystallised product is in the form of a colourless powder. It is likewise free of uncon-verted ketene d;mer.
Melting point: 49 - 51C
Elemental analysis:
calculated C 78.8û% H 1Z.73% N 2.58% 0 5.89%
10 found C 78.7Y. H 12.8% N 2.9% 0 5.6%.
Example 5: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 1.5 parts (0.025 mol) of 1,2-diaminoethane are used, affording 26.8 parts (100~ of theory) of the crude reaction product of the formula ( 2 2 ~ NH - CH - CH - NH
CO CO
2)q 3 1 ( 2)q 3 CO CO
( CH2 ) q ~ -CH3 ( CH2 ) , -CH3 q and ~' as defined in formula (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the 20 form of a colourless powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 110 - 113C

~23~3~

Elemental analysis:
calculated C 78.59% H 12.81% N 2.62~ 0 5.98%
found C 78.6% H 13.7~ N 2.8% 0 5.9%
Example 6: Example 1 is repeated, except that 25.3 parts tO.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 1.8 parts (0.025 mol) of 1,3-diaminopropane are used, affording 27.1 parts (100% of theory) of the crude reaction product of the formula ~23) NH - CH2 - CH2 - CH2 - NH
CO Co I ( 2 q 3 1 ( 2 q 3 CO CO

2 q 3 (CH2)q,~CH3 q and q' as defined in formula (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the form of a colourless powder. It ;s likewise free of uncon-verted ketene dimer.
15 Melting point: 89 - 91C
Elemental analysis:
calculated C 78.68% H 12.84% N 2.58% 0 5.90%
found C 78.2% H 12.6% N 2.8% 0 6.4%.
Example 7: Example 1 is repeated, except that 35.4 parts (0.07 mol) of the dimer of the ketenes of the formulae (16) and (17) and 4.1 parts (û.035 mol) of 1,6-diaminohexane are used, affording 39.5 parts (100% of theory) of the crude reaction product of the formula ~2~83Z~

(24) z CTI;~ CH2 - CH2 - CH - CH - NH
CO CO

2 ) q 3 ~ 2 q 3 CO CQ
(CH2\ql-cH3 (C~2) q, -CH3 q and q' as defined in formula (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the S form of a colourless powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 96 - 98C
Elemental analysis:
calculated C 78.94% H 12.89% N 2.49% 0 5.68%
10 found C 79.0% H 13.1% N 2.9% 0 5.0%.
Example 8: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 2.2 parts (0.017 mol) of bis(3-aminopropyl)-amine are used, affording 27.5 parts ~100% of theory) of the crude reaction product of the formula I H2 CH2 CH2 - NH - C~2 - CH2 - CH2 - NH
CO CO ~0 ( 2) q 3 CH ( 2)q 3 CH (CH2)q 3 CO CO
CO
(CH2)q~~C~3 (C;~)ql~CH3 2 q 3 ci and q' as def;ned in formuLa (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the form of a colourless powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 68 - 70C

Elemental analysis:
calculated C 78.S0% H 12.99% N 2.59% 0 5.92%
found C 78.7% H 13.1% N 2.9% 0 5.3%.
Example 9: Example 1 is repeated, except that 25.3 parts (0~05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 2.2 parts (0.013 mol) of 1,2-bis(3-aminopropyl-amino)-ethane are used, affording 27.5 parts (100% of theory) of the crude reaction product of the formula (26) ~NH - CH2 - CH2 ~ CH~ - NH CH2 CO CO
CH (C 2)q C 3 C ( 2)q 3 CO CO

2 q 3 2 S' 3 _ 2 q and q' as defined in formula (18)~
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the form of a colourless powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 52 - 55C
Elemental analysis:
calculated C 78~84% H 12~78% N 2.55% 0 5.83%
found C 78~8% H 12r4% N 3.0% 0 5~8%~
Example 10: Example 1 is repeated, except that 25~3 parts (0~05 mol) of the dimer of the ketenes of the formula (16) and (17) and 8.2 parts (about 0.025 mol~ of a technical mix-ture of N-(3-aminopropyl)hexadecylamine, N-(3-aminopropyl)-heptadecylamine and N-(3-aminopropyl)octadecylamine, afford-ing 33A5 parts (100% of theory) of the crude reaction product mixture of the formula ~23~32~

(27) Ql - N - CH~- CH2 - CH2 - NH

CO Co 2 q 3 1 ( 2 q 3 CO CO

(CH2)ql-cH3 2 q 3 q and q' as defined in formula (18).
r~1 = a mixture of C16-, C~7- and C18- alkyl.
The crude product mixture is recrystallised from S acetone. The recrystallised product m;xture is in the form of a yelLow;sh powder. It is l;kewise free of unconverted ketene d;mer.
Melt;ng po;nt: 69 - 72C.
Example 11: Example 1 is repeated, except that 25.3 parts (0.05 mol~ of the dimer of the ketenes of the formula (16) and (17) and 10.9 parts (about O.OZ5 mol) of a technical mix-ture o~ N-(3-aminopropyl)eicosylamine and N-(3-aminopropyl)-docosylamine, affording 36.2 parts (100% of theory) of the crude reaction product mixture of the formula 15 (2~) Q2 N CH2 CH2 - CH2 - NH
CO CO
I ( 2 q 3 CIH (CH2)q 3 CO CO
(CH2)4~-CH3 2 q 3 q and q~ as defined in formula ~18).
Q2 = a mixture of C20- and C22-alkYl' The crude product mixture is recrystallised from acetone. The recrystallised product mixture is in the form of a yellowish powder. It is likewise free of unconverted ketene dimer.
MeLting point: 48 - 52C.

Example 12: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 2.7 parts (0.025 mol) of 1,3-diaminobenzene are used, affording 28.0 parts (100% of theory) of the crude reaction product of the formula (29) ~ H
CO \- CO

1 2 q 3 ICH (CH2)q CH3 CO CO
2 q 3 2 q 3 q and q' as defined in formula (18).
The crude product is recrystallised from acetone for analytical purposes. The recrystallised product is in the form of a colourLess powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 52 - 55C.
Elemental analysis:
calculated C 79.51% H 12.26% N 2.51% 0 5.72%
15 found C 78.8% H 12.4% N 2.3% 0 6.5%.
ExampLe 13: Example 1 is repeated, except that 35.4 parts tO.07 mol~ of the dimer of the ketenes of the formulae ~16) and ~17) and 4.8 parts (0.035 mol~ of a~a~-diamino-m-xylene are used, affording 40.2 parts (100% of theory) of the crude reaction product of the formula NH - CH - ~ - CH - Na CO CO

I ( 2)q 3 Cla (CH2)q ~H3 CO Co (CH2) q -CH3 2 q 3 q and q' as defined ;n formula (18).

3æ~

The crude product is recrystallised from dioxane for analytical purposes. The recrystallised product is in the form of a colourless powder. It is likewise free of uncon-verted ketene dimer.
Melting point: 105 - 108C
Elemental analysis:
calculated C 79.67% H 12.31% N 2.44% 0 5.58%
found C 80.0% H 12O3% N 2.4% 0 5.3%.
Examele 14: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 5.0 parts (0.025 mol) of 4,4'-diaminod;phenyl ether are used, affording 30.3 parts (100% of theory) of the crude reaction product of the formuLa ( 31 ) NH ~
CO CO
C~H (CH2)q 3 1 ( 2 q 3 CO CO
(CH2)q' ~H3 (CH2)ql-cH3 q and q' as defined in formula (18).
The crude product is recrystallised from acetone for analyt;cal purposes. The recrystallised product is slightly yellowish. It is likewise free of unconverted ketene dimer.
Melting point: 105 - 108C
2û Elemental analysis:
calculated C 79.41% H 11.66% N 2.32% 0 6.61%
found C 79.4% H 11.5% N 2.2% 0 6.9%.
Example 15: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketene of the formulae ~16) and (17) and 2.3 parts (0.025 mol) of 1,3-diamino-2-propanol are used, affording 27.6 parts (100% of theory) of the crude reaction product of the formula ~23~B329t OH
(32) NH - CH2 - CH - CH2 - NH
CO CO

2 ) q 3 1 ( 2 ) q 3 CO CO
2 q 3 ( CH2 ) q, -CH3 q and q' as defined in formula (18)~
The crude product is recrystallised from dioxane for analytical purposes. The recrystallised product is in the form of a colourless powder. It is likewise free of uncon-verted ke~ene dimer.
Melting point: 98 - 100C.
Elemental analysis:
calculated C 77.53% H 12.65% N 2~55% 0 7.27%
10 found C 77.7~ H 12.6% N 2.1% 0 7.6%.
Example 16: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae tl6) and (17) and 1.8 parts (0.025 mol) of 1,2-diaminopropane are used, affording 27.1 parts (100% of theory) of the crude reaction product of the formula (33) Co CO
CH- (CHZ) q~CH3 1 ( 2 q 3 CO CO
(CH ) q, -CH3 (CH2) q, -CH3 q and q' as defined in formula (18)~
The crude product is recrystallised from ethyl ace-tate for analyt;cal purposes. The recrystallised product is in the form of a colourless powder. It is l;kewise free of unconverted ketene dimer.

~Z3~32~

Melting point: 98 - 100.
Elemental analysis:
calculated C 78.68% H 12.83~ N 2.59% 0 5.90%
found C 78.8~ H 12.6% N 2.6% 0 6.0%.
xample 17: Example 1 is repeated, except that 25.3 parts (0.05 mol) of the dimer of the ketenes of the formulae (16) and (17) and 2.9 parts (0.025 mol) of 1,~-diaminocyclohexane are used, affording 28.2 parts (100% of theory) of the crude reaction product of the formula 10 (34) ~lH C~ ~2 ~-\CH - NH
i CH - CH
CO co CH ( 2)q 3 IH (CH2)q 3 CO CO

2 q 3 (CH2)q'-c~3 q and q' as defined in formula (18).
The crude product is recrystallised from ethyl ace-tate for analytical purposes~ The recrystallised product is in the form of a colourless powder. It is likewise free of 15 unconverted ketene dimer.
Melting point: 120 - 125C.
Elemental analysis:
calculated C 79.08% H 12.74% N 2.49% 0 5.69%
found C 78.2% H 12.5% N 2.7% 0 6.6%.
ZO Application Examples Examples 18 and 19: A dispersion of bleached birch sulfate pulp and pine sulfate pulp fibres in a weight rat;o of 1:1 in 1û hard tGerman degrees of hardness) water and having a Schopper-Riegler freeness of 35 and a solids content of 0.5% is admixed with 20% of chalk as a filler, followed by 0.01% of PERCOL 292~ (a cationic h;gh molecular weight (> 1x107) polyacrylamide) as an aid for retaining very fine pulp fibre particles, the dispersion of the fibres attaining the pH given in Table I below. The percentages are based ~23~24 on dry substance cf aid and filler, based on the solids con-tent of the dispersion of the fibres~
Formulations of the sizing agent are prepared by stirring 7~ each of the specified reaction products as crude S produc~ in powder form~ as sizing agent, with, in each case, 3.5% of POLYMIN P~ (a polyethyleneimine which has a mole-cular weight of 10,000 to 100,000), as a retention aid, in the presence of deionised water and glass beads having a dia-meter of 2 mm. The resulting dispersions are homogeneous, pourable and stable. The percentages are based on dry sub-stance of sizing agent and retention aid, based on the total weight of the formulation.
The aqueous formulation of the sizing agent and the retention aid is then added to the dispersion of the fibres in such an amount that the amount of s;zing agent present in the dispersion is 0.5~ on the dry substance of the sizing agent, based on the solids content of the dispersion of the fibres. The dispersion of the fibres is then processed in a laboratory sheet former to give sheets of paper which, following a first drying at 130C for 3 minutes, have a weight per unit area of 80 g/m2. The sheet of paper thus obtained is subjected to an additional thermal treatment at 140C for 3 minutes.
The two surfaces of the sheets of paper obtained~
i.e. the surface obtained on the sieve side of the sheet former and the opposite surface are tested for their sizing properties. For this purpose, the Cobb water absorption on 30 seconds' exposure (WA Cobb30) is measured in accordance with DIN 53,132. The results of the WA Cobb30 measurements in g/m on the sieve s;de (SS) and the opposite side (OS) are given in Table I, before and after the thermal treatment at 140C and before and after storage at 20C for one day.
The lower the water absorption, the better is the sizing of the paper. WA Cobb30 ualues above 100 correspond to com-pletely unsatisfactory sizing of the paper.

~23~332~

L t =.~ .

1~1 Q ~ Q ~
C~) C Q ~ Q
O ~ O ~
' V 11~ V UJ
~1 o ~ 1_ ''1 U ~

~3~3Z9~

Examples 20 and 21: The method of Examples 18 and 19 is repeated, except that each of the formulations is prepared with one of the reaction products given in Table II, below, as a sizing agent.
The sizing results are summarised in Table II, bel.ow~

~2383Z~

r :L

~1 ~ . ;~ ;

Examples 22 to 24: The method of Examples 18 and 19 is repeated, except that each of the formulations is prepared with one of the reaction products given in Table III, below, as a sizing agent.
S The s;zing results are summarised in Table III, below.

~.23fl324 _ ~ ; ~ ~ ~
E ':) _ ~ ~V) O`
,~ ~V~ ~_ N1~1 E ~
G~
~, O ~ ___ ..~ __ D (l~>~
O E ~
I~ . <~) U~ ~J~) 3 L ~O ~ ~ ~
V
_ ~V~ 00 00O
E ~v~ ~1 r~l u~
t_ ..
a C O ~ r~
L O
O ~ ~ (~I O1~) Q Il~ ~ r~l ~ ~
~ - - - ~

~ ~ l~ o~
I ~ 00 CO CO
CL ~ .

~ ~ ~ ~ O
L O O`L
n~ Q ~IJQ ~IJ ~1 ~
~) C QC Q C Q
C O E O E O E
., ~- ~U ~_ ~ _ ns N ~ X ~ X ~ X
., ~ LU ~ ~11 a~ ~ ~ ~ a ~ ~ O Q~ O ~ O , _ ~Ll _ E O I~J ~ ~
n ~ z N ~1 N
l_ X
, ~

ExampLes 25 and Z6: The method of Examples 18 and 19 ;s repeated, except that each of the formulations is prepared with one of the reaction products given in Table IV, below, as a sizing agent.
The sizing results are summarised in Table IV, below~

~23832~

~
J

I ~
_ _ Il) L O ~-(~l Q ~ Q
~) _ ., O E O E
N ~ X ~ X
'V~ LL Q~

'I , o ~r o _ E O Il~ ~o I_ Z , `J 1~1 ~;~3~3~24 Example 27: The method of Examples 18 and 19 is repeated, except that each of the formulations is prepared w;th one of the reaction products given in Table V, below, as a sizing agent.
The sizing results are summarised in Table V, below.

~8324 3 ~ ~ O 1~
; ~ ~
, n ~o ~ N
O
aJ
O n ~
_ __ .__ ~ V
O
t~ Q
C O E
N ~ X
.~ LL
_ ~Y O .

_ ¦ E O I~
~1 ~x , ~ LL

~3~324 Examples 28 and 29: The method of Examples 18 and 19 is repeated, except that each of the formulations is prepared with one of the reaction products given in Table VI, below, as a sizing agentO
The sizing results are summarised in Table VI below.
Table VI

Example Siz~ng agent pH of the WA Cobb30 ~g/m ) No. dispersion _ _ _ before thermal treatment ~_ _ after 1 day .. ~ . _._ 28 Reaction product _ of ExampLe 5 8.4 17 29 Reaction product of Example 6 8.3 17 17 Example 30: The method of Examples 18 and 19 is repeated, except that the following formulation is used of the sizing agent which is emulsified at 80C in the molten state in the presence of water:

7 % of the reaction product of Example 11, as sizing agent 3.5% of POLYMIN P~, as a retention aid 0.7% of sorbitan monostearate as an oil-in-water emulsifier 0.7% of an adduct of ethylene oxide and sorbitan monostearate as a water-in-oil emulsifier.
This formulation is homogeneous and stable.
The sizing results are summarised in Table VII~ below.

~L23~;~24 Table VII

Example pH of the WA Cobb30 (g/m ) No. dispers~on __ before thermal treatment after thermal treatment _ .. ... __ _ __ at once after 1 day at once , OS SS OS SS I OS

8.4 16 33 12 34 ¦ 13 Examples 31 and 34: The method of Examples 18 and 19 is repeated, except that each of the formulations is prepared with one of the reaction products given in Table VIII, below, as a sizing agent.
The sizing results are summarised in Table VIII, below.

Table VIII

Example Sizing agent pH of the WA Cobb30 No. dispersion before thermal treatment at once _ _. ~ SS OS
31 Reaction product . of Example 14 8.8 39 14 32 Reaction product of Example 15 9.0 42 17 33 Reaction product of Example 16 8.8 46 15 34 Reaction product of Example 17 9.1 55 15

Claims (27)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for sizing paper or cardboard which comprises adding in any order or simultaneously to aqueous dispersions of the fibers (A) an anionic hydrophobic sizing agent which is obtainable from (a) ketene dimers and (b) diamines or oligoamines, and (B) a polymeric cationic retention aid.

2. A process according to claim 1 in which the component (A) is a sizing agent which has a molecular weight of 1,000 to 4,000.

3. A process according to claim 1 in which the component (a) is a dimer of the ketenes of the formulae R1-CH=C=O and R?-CH=C=O in which R1 and R? are identical or different and each is a hydro-phobic substituent having at least 5 carbon atoms, provided that at least one of the radicals R1 and R? has at least 8 carbon atoms.

4. A process according to claim 1 in which the component (a) is a dimer of the ketenes of the formulae R2-CH=C=O and R?-CH=C=O in which R2 and R? are identical or different and each is alkyl or alkenyl having 5 to 22 carbon atoms, cycloalkyl having 5 to 12 carbon atoms or aryl, alkaryl or aralkyl having 6 to 10 carbon atoms, provided that at least one of the radicals R2 and R? has at least 8 carbon atoms.

5. A process according to claim 1 in which the component (a) is a dimer of the ketenes of the formulae R3-CH=C=O and R?-CH=C=O, the two ketenes being unsaturated or saturated fatty acid radicals having 8 to 22 carbon atoms and R3 and R? are identical or different, provided that at least one of the R3 and R? radicals are fatty acid radicals which have at least 8 carbon atoms.

6. A process according to claim 1 in which the component (a) is a dimer of the ketenes of the formulae R4-CH=C=O and R?-CH=C=O, the two ketenes being radicals from lauric, palmitic, stearic, oleic or behenic acid or mixtures thereof and R4 and R? are identical or different.

7. A process according to claim 1 in which the component (b) is an aliphatic, cycloaliphatic, aromatic, araliphatic or heterocyclic diamine or oligoamine having 2 to 6 nitrogen atoms and 2 to 36 carbon atoms.

8. A process according to claim 1 in which the component (b) is a diamine or oligoamine of the formula D1-NH-A1-NH2 in which A1 is alkylene, hydroxyalkylene, alkenylene or cycloalkylene having at most 12 carbon atoms, naphthylene or a radical of the formula D1 is hydrogen or an alkyl or alkenyl radical from fatty acids having 8 to 22 carbon atoms, E1 and E? each are ethylene or n-propylene, n1, n2, n3 and n4 each are 1, 2 or 3, and m is an integer from 1 to 4.

9. A process according to claim 1 in which the component (b) is a diamine or oligoamine of the formula D2-NH-A2-NH2 in which A2 is un-substituted, straight-chain or branched alkylene or hydroxyl-substituted straight-chain alkylene having 2 to 9 carbon atoms, cyclopentylene, cyclohexylene, phenylene, toluylene, xylylene, di-phenylene ether or -(CH2-CH2-NH) -CH2-CH2 , D2 is hydrogen or, if A2 is alkylene, an alkyl or alkenyl radical from a fatty acid having 8 to 22 carbon atoms, and m is an integer from 1 to 4.

10. A process according to claim 1 in which the component (b) is a diamine or oligoamine of the formula D3-NH-A3-NH2 in which A3 is alkylene which is unsubstituted or substituted by one methyl or hydroxyl radical and has a total of 2 to 6 carbon atoms, cyclohexylene, phenylene, xylylene, diphenylene ether or -(CH2-CH2-NH) -CH2-CH2-, D3 is hydrogen or, if A3 is alkylene, an alkyl or alkenyl radical from lauric, palmitic, stearic, oleic or behenic acid or mixtures thereof, and m is an integer from 1 to 4.

11. A process according to claim 1 in which the retention aid (B) has a molecular weight of 1,000 to 2,000,000.

12. A process according to claim 1 in which the retention aid (B) used is a polyalkyleneimine, epihalogenohydrin adducts of reaction products of polyalkylenepolyamines and of aliphatic dicarboxylic acids or of reaction products of polyalkylenepolyamines, of dicyanodiamide and unesterified or alkanol-esterified, organic dicarboxylic acids, a reaction product of dicyanodiamide, of formaldehyde, of ammonium salts of strong inorganic acids and of alkylenediamines or poly-alkylenepolyamines, a cationically modified starch or carbohydrate from carob bean or guar bean flour, a copolymer based on poly-amide-amines or a reaction product of epihalogenohydrins and of polymerised diallylamines.

13. A process according to claim 1 in which 0.02 to 3 per cent by weight of the sizing agent (A) and 0.03 to 3 per cent by weight of the retention aid (B), each based on dry substance of (A) and (B) and on the solids content of the dispersion of the fibers, are used.

14. A process according to claim 1 in which the optional fillers are condensation products of formaldehyde and urea, titanium dioxide, talc, kaolin, montmorillonite or chalk.

15. A process according to claim 1 in which the dispersion of the fibers has a pH value of 3.5 to 10Ø

16. A process according to claim 1 in which the dispersion of the fibers has a Schopper-Riegler freeness of 20 to 60° and a solids content of 0.1 to 5 per cent by weight.

17. A process according to claim 1 in which the dispersion of the fibers contains sulfite or sulfate pulp of softwood or hardwood.

18. A process according to claim 1 in which the dispersion of the fibers additionally contain mechanical wood pulp or alum-containing waste paper.

19. An aqueous composition for carrying out the process according to claim 1 in which the sizing agent (A) and the retention aid (B) are added separately in any order to the dispersion of the fibers, which contains the sizing agent (A), partly or completely in the form of salts.

20. An aqueous composition for carrying out the process according to claim 1 in which the sizing agent (A) and the retention aid (B) are added simultaneously to the dispersion of the fibers, which contains (A) 2 to 40 per cent by weight of sizing agent and (B) 0.1 to 20 per cent by weight of retention aid, each based on dry substance of (A) and (B) and on the weight of the aqueous composition.

21. A reaction product which is obtainable from (a) ketene dimers and (b) diamines or oligoamines.

22. A reaction product of ketene dimers and diamines or oligoamines, or salts thereof, which has the formula in which A0 is alkylene, hydroxyalkylene, alkenylene or cycloalkylene having at most 12 carbon atoms, naphthylene or a radical of the formula E1 and E2 each are ethylene or n-propylene, D1 is hydrogen or an alkyl or alkenyl radical from fatty acids having 8 to 22 carbon atoms, m is an integer from 1 to 4, and R1 and R? are identical or different and each is a hydrophobic substituent having at least 5 carbon atoms, provided that at least one of the radicals R1 and R? has at least 8 carbon atoms.

23. A process for preparing a reaction product according to claim 22, which comprises reacting (a) a dimer of a ketene of the formulae R1-CH=C=O and R?-CH=C=O, in which R1 and R? are as defined in claim 22 with (b) a diamine or oligoamine of the formula D1-NH-A0-NH2 or D1-NH-(E1-NH)-E?-NH2, in which A0, D1, E1, E? and m are as defined in claim 22.

24. A process according to claim 23 which additionally comprises con-verting the resulting reaction products by means of ammonia or an alkali metal hydroxide in an aqueous medium partly or completely into the corresponding salts.

25. A process according to claim 23 in which 1 to 1.1 equivalents of amino group of component (b) are used per mol of component (a).

26. A process according to claim 23 in which the reaction is carried out at 10 to 140°C in the melt or in an inert organic solvent.

27. A process according to claim 1 wherein the aqueous dispersion of the fibers additionally contains at least one filler.