DE19625824A1 - Process for making paper products and sizing composition usable therein - Google Patents

Abstract

A process for making paper products is described in which sizing is effected by use of a hydrophobic cellulose-reactive sizing agent in combination with a promoter. As promoters water-insoluble bases are used which are formed by the reaction of saturated fatty acids, unsaturated fatty acids, hydroxy substituted fatty acids and/or mixtures thereof and alkanoldimaines and/or aliphatic polymaines. Further a corresponding paper sizing composition is described which comprises a hydrophobic cellulose-reactive sizing agent and such a promoter. The combination of hydrophobic celluulose-reactive sizing agent and promoter provides a synergistic effect so that for achieving the same sizing level a lower amount of hydrophobic cellulose-reactive sizing agent is required. Alternatively at the same concentration of the hydrophobic cellulose-reactive sizing agent a higher sizing level can be achieved.

Description

The invention relates to a process for the preparation of Paper products in which the sizing by using a hydrophobic cellulose-reactive sizing agent in combination is effected with a sizing promoter. Furthermore, the Invention A sizing composition for use in a process for producing paper products containing a hydrophobic cellulose-reactive sizing agent and a Sizing promoter.

Hydrophobic cellulose-reactive sizing agents are becoming large Scope used in the production of paper and cardboard. As she are insoluble in water, they are in the form of an emulsion used. To the desired sizing and liquid repellency get the finished paper, must be relatively large Amounts of cellulose-reactive sizing agents are used. The addition of large amounts of hydrophobic cellulose-reactive However, sizing agents can have a variety of different problems  in the papermaking process, e.g. B. deposits on the sieves and felts, high concentrations of hydrolyzed Sizing agents, friction problems and adhesion problems Ink toner on copy paper. Therefore, a reduction of to be used for obtaining the necessary degree of sizing Size of sizing not only big savings in the Material costs, but the aforementioned problems eliminate or at least significantly reduce. Furthermore could be used in applications of paper related to liquid in which the smell and taste of the finished cardboard of Meaning are derived from the sizing emulsion undesirable substances are minimized.

To the required amount of hydrophobic cellulose-reactive To reduce sizing agents is present in the art been beaten, water-soluble cationic polymers as Promoter to use. These have strong cationic polymers but the disadvantage that they the effectiveness of optical Brightening, which helps to improve the whiteness of the paper used, significantly affect what a Increased consumption of optical brighteners leads (see detailed representation in DE-PS 39 20 356).

It has now surprisingly been found that wasserunslösliche bases made from amines and fatty acids suitable promoters for hydrophobic cellulose-reactive sizing agents are.

Accordingly, the invention relates to a method for Production of paper products, in which the sizing by Use of a hydrophobic cellulose-reactive sizing agent in combination with a promoter, wherein as Promoter is a water-insoluble base selected from the group consisting of the reaction products used by the conversion of fatty acids selected from the group consisting from saturated fatty acids, unsaturated fatty acids, hydroxy substituted fatty acids and mixtures thereof and amines  selected from the group consisting of alkanediamines and aliphatic polyamines are formed.

Furthermore, the invention relates to a sizing agent for use in methods of making paper products that are a hydrophobic cellulose-reactive sizing agent and a promoter, wherein the promoter is a water insoluble base selected from the group consisting of Reaction products is by reaction of fatty acids selected from the group consisting of saturated fatty acids, unsaturated fatty acids, hydroxy-substituted fatty acids and Mixtures thereof and amines selected from alkanediamines and aliphatic polyamines are formed.

Preferred embodiments of the invention will become apparent from the following description and the claims.

Hydrophobic cellulose-reactive sizing agents are in the state of Technique known and for example in US-PS 3,130,118 be which are hereby incorporated by reference. Reference is further made to the definition of for Paper sizing suitable alkylketene dimers in DE-AS 25 33 411 and DE-AS 23 35 756.

Suitable sizing agents for use in combination with the water-insoluble base promoter are selected from the group consisting of:

• a) acid anhydrides of the formula: in which R₂ and R₃ are the same or different and each represents hydrocarbon radicals having from 7 to 30 carbon atoms;
• b) cyclic dicarboxylic acid anhydrides of the formula: in which R₄ contains 2 or 3 carbon atoms and R₅ is a hydrocarbon radical of 7 to 30 carbon atoms;
• c) ketene dimers of the formula: (R₆CH = C = O) ₂, in the R₆ is a hydrocarbon radical having 6 to 30 carbon atoms and preferably an alkyl radical having 6 to 22 carbon atoms is atoms; and
• d) isocyanates of the formula: R₇-N = C = O, in the R₇ a hydrocarbon radical having 7 to 30 carbon is atoms.

A preferred compound of the acid anhydrides mentioned under a) is stearyl anhydride, while a specific example of a suitable cyclic dicarboxylic acid anhydride according to b) Isooctade kenylsuccinic anhydride. For the ketene dimers according to c)  are as hydrocarbon radical and cyclic alkyl and Aryl radicals suitable, although a saturated radical such as a Alkyl radical is most preferred.

Of the four groups a) to d) of the cellulose-reactive agents are the cyclic dicarboxylic anhydrides according to b) and the Ketene dimers according to c) most preferably, wherein the ketene dimers are particularly preferred.

Preferably, the hydrocarbon radicals R₂, R₃, R₆ and R₇ saturated, straight-chain radicals, but which are unsaturates and may have cyclic or aromatic substituents. R₅ is preferably a saturated straight-chain or branched-chain one Alkyl. Furthermore, R₂, R₃, R₆ and R₇ should preferably 14 to 22 carbon atoms and R₅ preferably 14 to 30 carbon atoms. The hydrocarbon groups R₂, R₃, R₄, R₅, R₆ and R₇ in each of the above formulas may also be substituted, z. B. with halogen such as chlorine, if a special Effect is desired.

The present invention suitable water-insoluble base promoters are reaction products by the reaction of fatty acids and amines are formed. These compounds are known and are often referred to as Wachsamine. Beyond that they are proposed for paper sizing (see DE-AS 10 12 165, AS 10 30 671, EP-A-0 005 201, EP-B-0 008 761 and US Pat. No. 5,393,334). However, these wax minerals are never for use in the Paper sizing in combination with hydrophobic cellulose-reactive Sizing agents have been proposed. This is especially true for Alkylketene dimers (AKD), alkenyl succinic anhydrides (ASA) and Fatty isocyanates which are the preferred sizing agents in the invention to the inventive method and in the inventive combination represent.

Suitable fatty acids for the reaction with amines for the preparation the water-insoluble base promoters are in general  Fatty acids having a carbon chain length of C₆ to C₂₂. you may be branched or unbranched. Preferred are fatty acids having a carbon chain length of C₁₂ to C₁₈. examples for Suitable saturated fatty acids are myristic acid, palmitic acid and stearic acid. Examples of suitable unsaturated fatty acids are oleic acid, linoleic acid, linolenic acid and eleostearic acid. A suitable hydroxy-substituted fatty acid is ricinoleic acid. Of course, mixtures of fatty acids can be used become.

For the reaction with the fatty acids suitable amines are Alkanediamines (aliphatic diamino alcohols) such as aminoethyletha nolamine, aminobutylethanolamine, aminomethylethanolamine and others alkyl-substituted aminoethanolamines and aliphatic polyamines such as triethylenetetramine or diethylenetriamine.

The water-insoluble ones produced from fatty acids and amines Bases preferably have a melting point below 100 ° C.

In general, fatty acids and amines are in such amounts reacted with each other, the molar ratios of 0.5: 1 to 10: 1 and preferably 1: 1 to 2: 1 correspond. The reaction of fatty acids and amines to form the water-insoluble Bases occur at high temperatures, preferably about 200 ° C. But it can also lower temperatures down to 150 ° C can be used. However, lower temperatures require longer times to complete the reaction. The Reaction product is then allowed to cool. If the received Waxy amine is a solid, it is preferred to use the solid product for ease of handling, to a particulate form such as flakes, granules, powder, etc. to process. In terms of further details of the preparation of the invention suitable water-insoluble bases are those mentioned above References directed that make up appropriate reaction conditions and other suitable reaction components.  

Since the base promoters according to the invention are water-insoluble, they must be emulsified or dispersed. The water insoluble Base and the hydrophobic cellulose-reactive sizing agent Both are emulsified and separated or as a combined product added in the papermaking process. In this context It is important to point out that the emulsion or Dispersion of water-insoluble bases without the use of Surfactants is produced, which is another advantage As surfactants often sizing efficiency and paper quality affect.

The weight ratio of hydrophobic cellulose-reactive Sizing agent and water-insoluble base may be present within Areas such as 1: 100 to 100: 1 and preferably 30: 100 to 100: 30 vary. In general, the hydrophobic cellulose reactive sizing agents in an amount of up to 10 kg / ton Paper, preferably 0.2 to 5 kg / ton of paper, and the water insoluble base in an amount of up to 10 kg / ton of paper, preferably 0.25 to 2 kg / ton of paper used.

In the practice of the invention, the water-insoluble base becomes in amounts of 5 to 15 wt.%, preferably 8 to 10 wt Water dispersed or emulsified. Acid like organic acids, For example, acetic acid or formic acid, as PH regulator used. In addition, the aqueous Dispersion or emulsion of the water-insoluble base if thickeners such as derivatives of guar gum (anionic, nonionic or cationic) or xanthan gum, viscosity Regulators such as sodium acetate or sodium chloride or other types of salt, antifoam and preservatives contain. Of course, others for paper makers Adding suitable additives may be added exposed that they are not in undesirable interaction with the hydrophobic cellulose-reactive sizing agent and the water insoluble base and the paper sizing efficiency of impair combination according to the invention.  

The invention is particularly advantageous for the production of Paper products containing fillers such as chalk, precipitated calcium carbonate, clay, kaolin, talc and the like contain. The amount of filler used in the paper can be considerable vary, but generally does not exceed 30% by weight. For example, fine paper usually contains 15 to 25% by weight. Filler.

The combination of hydrophobic cellulose-reactive sizing Medium and water-insoluble base shows a considerable synergistic effect, d. H. the paper sizing efficiency of Combination is significantly higher than the sum of the efficacies of the individual components (see the examples below). Accordingly, the sizing efficiency becomes a predetermined one Dosage of hydrophobic cellulose-reactive sizing agent by the addition of the base promoter improved. On the other hand, one is lower dose of hydrophobic cellulose-reactive sizing by means required to achieve the same degree of sizing. Furthermore, the water-insoluble base promoters adversely affect the effectiveness of optical brightener is not what an important Advantage over the known water-soluble cationic Promoters (see above).

example 1

Into a 5 liter round bottom flask (equipped with a Dean-Stark trap, Cooler, temperature sensor, mechanical stirrer and nitrogen rinsing), 2187 g (7.95 mol) of tallow fatty acid mixture were added. The flask was then heated to 100 ° C under a nitrogen atmosphere heated and the tallow fatty acid to melt. To the hot melt was 520.75 g (5.0 mol) of aminoethylethanolamine given as soon as possible. The temperature of the melt rose due to the addition to 130 ° C. The flask was then heated to 200 to Heated to 205 ° C and held at this temperature until the Water formation stopped. The total amount of water collected was 170 g. The pale yellow, liquid residue product was  then cooled to 125 ° C and poured into large pyrex pans and allowed to cool to room temperature. The cream-colored wax like solid was then crushed and crushed. The Melting point was 58 to 60 ° C.

40 g of the amine wax thus prepared, 13.6 g of acetic acid (98%) and 266.4 g of tap water were mixed and stirred up Heated to 80 to 100 ° C. The mixture became for 30 minutes long touched. Then the mixture was made using an Ultra Turrax for 1 minute at 20 000 rpm dispersed. Subsequently were 79.8 g of a 0.5% aqueous solution of a cationic Guar gums as a stabilizer added to the mixture. Also one small amount of a preservative was added. The Dispersion was cooled rapidly to room temperature. The finished dispersion had a pH of 3.5 and a viscosity of 110 mPas.

Example 2

The pH of a bleached sulphate pulp of 50% pine and 50% birch was adjusted to about 8. The concentration of the pulp was about 0.7%. A two-component system, Hydrocol from Allied Colloids (cationic polyacrylamide and bentonite) was used as a retention aid. Chalk from Faxe Chalk was used as a filler and the ash content of the produced paper sheets was about 15%. The sizing agent used was a conventional AKD-based neutral size formulation. The AKD emulsion (AKD made from a mixture of stearic acid and palmitic acid) was obtained as follows:
56 g of cationic cornstarch was added to 1438 g of water. The slurry was heated to 95 ° C and this temperature was maintained for 30 minutes to boil the starch. 5.5 g of an emulsifier, namely a sulfonate-containing polymer, and 500 g of AKD were added with stirring. Then, the mixture was passed through a high-pressure homogenizer (Rannie, piston type) at a pressure of 120 bar. The homogenized premix was diluted with water to an AKD content of 20%. Small amounts of aluminum sulfate and preservatives were added to keep the formulation stable. A dilution of this AKD emulsion was used to prepare paper sheets.

The chemicals were added to the pulp as follows (the Concentration data refer to the active ingredients):

Time (seconds) chemicals 0 Chalk (ash content about 15%) 20 AKD emulsion (0.5 to 1.0 kg / ton of paper) 30 Cationic polyacrylamide, Hydrocol 852 (0.4 kg / ton of paper) 165 Bentonite, Hydrocol SH (2 kg / ton of paper) 180 Training of the sheet

Leaflets were made into a Rapid-Köthen-Blattbilder. The leaves were dried (90 ° C, 5 min) and cured (120 ° C, 10 min). The Cobb 60 values were measured. Cobb 60 corresponds to that of one unit area of the paper in 1 minute absorbed amount of water (method: SCAN-P 12:64). The lower the value, the better the sizing. The following results were obtained:

The same pulp system and the same chemicals were used with the Difference used that of the pulp slurry as well 1.0 kg / ton of wax amine from Example 1 was added has been.

Time (seconds) chemicals 0 Chalk (ash content about 15%) 10 Wax amine emulsion (1.0 kg / ton of paper) 20 AKD emulsion (0.5 to 1.0 kg / ton of paper) 30 Cationic polyacrylamide, Hydrocol 852 (0.4 kg / ton of paper) 165 Bentonite, Hydrocol SH (2 kg / ton of paper) 180 Training of the sheet

The following results were obtained:

It can be seen that the dosage of 1.0 kg / ton of paper a vigilante the effectiveness of the AKD-based Improved sizing agent. It is a lower dose of AKD required to achieve the same degree of sizing.

Example 3

To demonstrate the synergistic effect obtained by using the combination of hydrophobic cellulose-reactive sizing agent and water-insoluble base according to the invention, the experiment described in Example 2 was repeated 3 times. In Test 1, no AKD emulsion was added, but the amount of wax amine was varied between 0.5 and 1.0 kg / ton of paper. In Test 2, no wax amine was used and the dosage of the AKD emulsion varied between 0.5 and 1.0 kg / ton of paper. In Test 3, the dosage of the AKD emulsion was varied between 0.1 and 1.0 kg / ton of paper while the dosage of waxy amine was kept constant at 1.0 kg / ton of paper. The wax amine was a commercial product available under the trade name Reactopaque R 100. The results of all three experiments are summarized in Fig. 1.

As can be seen from the test results, the wax amine no sizing when used alone (test 1). The AKD emulsion gives the expected sizing (test 2). The combination from AKD emulsion and waxy amine provides a clear synergisti effect, as the results of Test 3 show.

Corresponding results were obtained in tests in which ASA instead of AKD as a hydrophobic cellulose-reactive sizing medium was used.

Claims (10)

1. A process for the production of paper products, in which the Sizing by using a hydrophobic cellulose reactive sizing agent in combination with a promoter is effected, wherein as a promoter, a water-insoluble base selected from the group consisting of the reaction Products used by the reaction of fatty acids selected from the group consisting of saturated fat acids, unsaturated fatty acids, hydroxy-substituted Fatty acids and mixtures thereof and amines selected from the group consisting of alkanediamines and aliphatic Polyamines are formed. 2. The method of claim 1, wherein an AKD emulsion as hydrophobic cellulose-reactive sizing agent used becomes. 3. The method according to claim 1 or 2, wherein the wasserunlösli Base in the form of an aqueous dispersion or emulsion is used. 4. The method according to any one of claims 1 or 3, wherein the hydrophobic cellulose-reactive sizing agents and the water-insoluble base in a weight ratio of 1: 100 to 100: 1 are used. 5. The method according to any one of claims 1 to 4, wherein the hydrophobic cellulose-reactive sizing agents in an amount from 0.2 to 5 kg / ton of paper and the water-insoluble base used in an amount of 0.2 to 2 kg / ton of paper become. 6. The method according to any one of claims 1 to 5, wherein the Pulp a filler is added.   7. sizing composition for use in a Process for the production of paper products containing hydrophobic cellulose-reactive sizing agent and a Promoter, wherein the promoter is a water-insoluble Base selected from the group consisting of the reaction is selected by the conversion of fatty acids from the group consisting of saturated fatty acids, unsaturated fatty acids, hydroxy-substituted fatty acids and mixtures thereof and amines selected from the group consisting of alkanediamines and aliphatic polyamines be formed. 8. The composition of claim 7, which is in the form of an aqueous Dispersion or emulsion is present. 9. The composition of claim 7 or 8, wherein the hydropho be cellulose-reactive sizing agent AKD. 10. The composition according to any one of claims 7 to 9, in which hydrophobic cellulose-reactive sizing agent and water insoluble base in a weight ratio of 1: 100 to 100: 1 present.