FI86317B - SOM PAPPERSLIMNINGSAEMNE ANVAENDBAR STABIL FAST SAMMANSAETTNING SOM INNEHAOLLER KETENDIMER. - Google Patents

Abstract

Particulate solids comprising ketene dimers may be obtained by drying a conventional aqueous dispersion of the dimer to which a water dispersable encapsulating agent has been added. Preferably the encapsulating agent is a cationic starch and the solid is obtained by spray drying the emulsion under controlled conditions. The products retain their sizing properties even on prolonged storage.

Description

1 86317

This invention relates to stable solid compositions containing a ketene dimer which are dispersible in water to form a paper sizing agent.

Ketene dimers are used as ingredients in paper sizing compositions. The sizing compositions are prepared as relatively concentrated aqueous dispersions which are diluted prior to use in the paper sizing process. The disadvantage of concentrated aqueous dispersions is that their paper sizing ability deteriorates during prolonged storage, apparently due to hydrolysis of the ketene dimer. In order to be able to act as paper sizing agents, the ketene dimers are dispersed in water with 0.2 to 2.5% by weight of surfactant and / or emulsifier, based on the weight of the ketene dimer. Attempts have recently been made to dry such dispersions, but attempts have failed. If the dispersion is dried slowly, the ketene dimer tends to hydrolyze. If the dispersion is dried at an elevated temperature, the ketene dimer tends to carbonize. If the dispersion is spray-dried, the material dries to a sticky, difficult-to-handle mass.

It has now been discovered that solid, particulate compositions can be prepared which contain a ketene dimer and a stabilizer which are paper sizing pro. are easily dispersible in water as required by the process and have improved stability during long-term storage. It is believed that the solid water-dispersible particles comprising ketene dimer solids and a stabilizer are novel and form one aspect of this invention.

* - *: For a stable solid composition according to the invention. The ketene dimer is characterized in that the ketene dimer has the formula 2 - 86317 R - CH = C - O II CH - C = O 15 wherein R is an alkyl, alkenyl, aryl or alkaryl group having 8 to 24 carbon atoms that the composition also contains a water-soluble stabilizer selected from the group consisting of gelatin, tristearin, gum arabic, sugars, ethylcellulose, carboxymethylcellulose, polyacrylic amides, water-soluble silicates, polyethers, polyesters, polyamides, and starches, and starches; that (a) the ketene dimer of the above formula and the water-soluble stabilizer are formed into an aqueous dispersion, and (b) the aqueous dispersion is dried to form a homogeneous particulate water-dispersible solid.

Ketene dimers useful as paper sizing agents are compounds having the molecular formula R - CH = C - 0

l I

CH - C = O

R

: Wherein R is an alkyl, alkenyl, aryl or alkaryl group having 8 to 24 carbon atoms. R is preferably an alkyl group having 8 to 20 carbon atoms. These dimers are normally prepared from fatty acids obtained from natural sources and are thus mixtures of dimers in which the number of carbon atoms of the substituent group R varies. Useful mixtures of ketene dimers in which R contains an average of 8 to 24 carbon atoms are useful in the practice of this invention. The group R preferably contains on average 12 to 18 35 carbon atoms and particularly preferably 14 to 18 carbon atoms. Examples of ketene dimers are octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, phenyl, benzyl, beta-naphthyl and cyclohexyl ketene dimers. prepared by the best known method for 5 minutes from montanic acid, naphthenic acid, Δ 910-decylenic acid, Δ 910-dodecylenic acid, palmitic acid, oleic acid, castor oil acid and eleostearic acid in racemic acid, and ketene dimers prepared in nature. -10 Mixtures of oil, palm kernel oil, palm oil, olive oil, peanut oil, rapeseed oil, beef tallow, lard (animal fat layer) and whale fat. Mixtures of all the above fatty acids can also be used.

Ketene dimers are prepared in the form of waxy solids consisting of mixtures of ketene dimers and impurities in which the amount of impurities can be up to 20% by weight. These products are normally used as is, i.e. without separating impurities. In this patent application, ketene dimers also mean mixtures of these and said impurities, and all parts by weight indicated on the ketene dimer are calculated on the weight of the finished product.

The stabilizer must be selected in such a way as to: ····; 25 lists the drying of the dispersion into a product which can be | redisperse in water to operate in paper sizing processes. The nature of the stabilizer must be such that it is compatible with the other components of the spray-dried product and such that it does not degrade during the drying process. Examples of compounds useful as stabilizers are gelatin, tristearin, acacia, sugars, ethylcellulose, carboxymethylcellulose, polyacrylamides, silicates, polyethers, poly-. Lyesters, polyamides, starches, in particular cationic:. 35 set of starches, and polyvinyl alcohol.

. ···. The amount of stabilizer used is proportional to the amount of ketene dimer contained in the dispersion and is normally adjusted to just enough to dry the dispersion. It is less recommended to use an excess of encapsulating agent. The amount of stabilizer to be added to the dispersion is normally 25 to 100, preferably 25 to 75% by weight of the weight of the ketene dimer in the dispersion. A preferred group of stabilizers consist of substances known to be useful as ingredients in paper sizing compositions. The amount of these materials used can be greater than the amount necessary for them to work effectively with the dimer, as they can improve the efficiency of the dry product used in the paper sizing processes. Examples of such substances are starches such as cationic starches. A particularly preferred group of stabilizers consists of substances known to be soluble in cold water, and preferred examples of which are certain cationic starches such as those sold under the trade names Solvitose NX and Perfecta-myl PLV. The stabilizer can be added to all ketene-20 dimer aqueous dispersions. However, it is highly recommended to add a stabilizer to the dispersion, which itself can be used as a paper sizing agent, whereby redispersing the dried product gives a dispersion which can be used as a paper sizing agent without the need to disperse any additional components to make the ____:25 adhesive.

Ketene dimer dispersions normally contain at least one surfactant whose presence in the dried product facilitates redispersion of the product in the paper sizing process. Examples of suitable surfactants are the sodium salts of naphthalene formaldehyde disulfonate condensates, polyoxyethylene sorbitan ester or sodium lignosulfonate.

:. The amount of surfactant added is normally in the range of 0.3 to 3.5% by weight based on the ketene dimer, preferably in the range of 1.25 to 2.5%.

I: 5 86317

The ketene dimer dispersions used in the spray drying processes may further contain other conventional ingredients such as emulsifiers, stabilizers, retention aids and slime inhibitors, although heat sensitive compounds must be avoided.

The ketene dimer dispersions particularly preferably contain a cationic polymer such as polyamine to improve the sizing ability of the dispersion paper. Examples of polymers useful in this patent application include water-soluble polyaminopolyamide epichlorohydrin resins, alkylene polyamine epichlorohydrin resins, poly (diallylamine) epichlorohydrin resins, polydialkyldimethylammonium chloride and polyethylene.

The polymer can be used in an amount such that the weight ratio of ketene dimer to polymer becomes 1.0: 1.0. However, as the amount of polymer increases, the product tends to become more and more sticky, and it is recommended that the weight ratio of ketene dimer to polymer be 1.0: 0.2 to 1.0: 0.5.

The dispersion of ketene dimer and stabilizer can be dried by a variety of techniques. However, exposing the dimer to high temperatures for extended periods of time may result in its decomposition by either carbonization or hydrolysis, and high temperatures should be avoided. Techniques such as angle drying and spray drying are preferred. We preferably use spray drying where the drying conditions must be controlled to minimize degradation of the ketene dimer. The ketene dimer dispersions can be spray-dried with conventional equipment. The temperature of the dryer must be adjusted to avoid significant charring or decomposition of the emulsion components. The temperature at the dryer inlet is typically in the range of 220 to 350 ° C and at the dryer outlet at 110 to 125 ° C. The drying process is carried out to obtain a finely divided product with less than 0.1% by weight of water.

6 86317

The powder products must be dispersed in an aqueous medium in order to be used in paper sizing processes. The powder is typically diluted with water up to ten times the weight of the powder.

5 The appropriate dispersion is preferably obtained by vigorous stirring. We preferably moisten and / or slurry the powder with a small amount of water, e.g. about 5-30% by weight of the total dilution water is added to the powder, and mix these slurries with an additional amount of water to the desired concentration, usually about 10% by weight.

The following examples illustrate the invention.

Example 1

A stearin / palmitine alkyl ketene dimer dispersion having the following composition (Composition 1) was prepared. 15

800 kg of water

Alkyl ketene dimer 100 kg

Orota SN * 1.24 kg

Quaternized poly-20 amine 100 kg

Mucolytic 400 ml * sodium salt of naphthalene formaldehyde sulphonate condensate

A cationic starch product sold under the trade name Perfectamyl PLV was added to one sample of the dispersion in an amount such that the weight ratio of ketene to starch was 1: 1 (Composition 2). The same cationic starch product was added to the second sample of the dispersion in an amount such that the weight ratio of ketene dimer to starch was 1: 0.5 (Composition 3).

Compositions 2 and 3 were then spray dried in a Niro Production Minor Spray Drier set for Rotary Atomization using an atomization speed of 24,000 rpm. The temperature of the liquid feed was 15 ° C, the temperature of the inlet to the dryer was 250 ° C and the temperature of the outlet of the dryer was .. 1 room 125 ° C. A white powder was obtained.

Il 7 86317 The sizing ability of these powders 2 and 3 and dispersion 1 was determined by a series of experiments.

Koe A

One minute Cobb value (g.m) 5 Composition Removed from dryer- Natural as 100 ° C swelling 1 42.6 20.9 2 39.3 20.6 10 3 71.5 23.4

Liimausolosuhteet

Pulp brown waste paper

Retention aid 0.02% solids by weight na 15 Amount of adhesive added 0.2% ketene dimer by weight

Koe B

One minute Cobb value (g.m)

Example Removed from the dryer- Natural drying at 100 ° C 1 40.4 35.3 2 46.0 35.5 3 42.9 32.0 25 Bonding conditions

Pulp bleached sulphite

Retention aid 0.02% solids by weight

The amount of glue added is 0.1% ketene dimer based on the mass

Koe C

One minute Cobb value (g.m)

Example Dehumidifier- Naturally dried at 100 ° C 35 ----- 1 69.2 38.8 2 37.8 25.0 3 32.2 25.5 8 86317

Liimausolosuhteet

Pulp brown recovered paper

Retention aid 0.02% solids by weight 5 Amount of adhesive added 0.2% ketene dimer by weight

Koe D

One minute Cobb value (g.m)

Example Dehumidifier- Naturally dried at 100 ° C 1 127.7 117.9 2 96.4 102.9 3 103.6 96.6 15 Bonding conditions

Pulp bleached sulphite

Retention aid 0.02% solids by weight

The amount of glue added is 0.1% of the ketene dimer by weight

Koe E

One minute Cobb value (g.m)

Example Dehumidifier- Naturally dried at 100 ° C 25 ----- 1 86.3 40.5 2 118.9 33.5 3 120.5 38.1

Bonding conditions 30 Pulp brown waste paper

Retention aid 0.02% solids by weight

The amount of glue added is 0.2% ketene dimer by weight based on li 9 86317

Koe F

One minute Cobb value (g.m)

Example Dehumidifier- Naturally dried at 100 ° C 5 ------ 1 90.7 81.7 2 32.6 25.3 3 30.3 26.7

Bonding conditions 10 Pulp bleached sulphite

Retention aid 0.02% solids by weight

Adhesive addition rate 0.2% by weight of ketene dimer 15 Experiments G and H used a product (composition 4) in which the ketene dimer was coated with 0.62% surfactant but otherwise identical and prepared under the same conditions as the composition described above. 3.

20 Koe G

One minute Cobb value (g.m)

Example Removed from the dryer- Natural when dried at 100 ° C 25 1 32.0 25.8 4 43.9 28.9

Bonding conditions: Pulp bleached sulphite + 5% chalk

Retention aid 0.02% by weight of solids

Adhesive addition amount 0.1% by weight of ketene dimer

Koe H

One minute Cobb value (g.m) 35 Example Removed from the dryer- Natural when dried at 100 ° C 1 36.0 23.3 4 34.5 25.0 10 8631 7

Pulp brown waste paper

Retention aid 0.02% solids by weight

The amount of glue added is 0.2% ketene dimer based on the mass

In Experiment J, a product (Composition 5) was used in which the ketene dimer was coated with 2.8% surfactant but otherwise identical and prepared under the same conditions as Composition 3.

10 Koe J

One minute Cobb value (g.m)

Example Removed from the dryer- Natural fiber 100 ° C melting 15 1 37.6 27.8 5 44.6 32.6

Liimausolosuhteet

Pulp bleached sulphite + 10% chalk

Retention aid 0.02% solids by weight

The amount of glue added is 0.5% by weight of ketene dimer

Example 2

A response stearin / palmitine alkyl ketene dimer dispersion having the following composition (Composition 6) was prepared.

Alkyl ketene dimer 100 kg Orotan SN 0.62 kg; Quaternized polyamine 50 kg • '-] Limantor jet 400 ml 30 Water 850 kg

A cationic starch product sold under the trade name Solvitose NX was added to this dispersion in an amount such that the weight ratio of ketene dimer to starch was 1: 0.5 (Composition 7).

The composition 7 was then spray dried under the conditions described in Example 1. The palatability of compositions 6 and 7 was determined after drying and at ambient temperature; il 8631 After 3.5 and 4.5 months of storage in 7 pens. The results were as follows:

One minute Cobb value (g.m)

Composition Removed from the dryer- Naturally dried at 100 ° C 6 28.2 24.2 7 31.6 25.4 After 3.5 months 10 6 26.2 27.0 7 33.6 26.5 After 4.5 months 6 62 .6 40.8 7 33.6 26.5 15 Bonding conditions

Pulp bleached sulphite

Retention aid 0.02% solids by weight

The amount of adhesive added is 0.1% ketene dimer based on the mass.

Claims (13)

1. Stable solid composition containing kentene dimers and dispersible in water to form a paper sizing agent, characterized in that the ketene dimer has the formula R - CH = C - 0 I I CH - C = 0 I Composition according to claim 1, characterized in that the stabilizing agent is a: cationic starch. Composition according to claim 1 or 2, characterized in that the particulate solid is obtained by potassium or spray drying. . 4. Composition according to claim 3, characterized in that the dispersion is spray dried and the temperature at the entry point of a wiper is 220 - 350 ° C and the temperature at the starting point of the wiper is': 110 - 125 ° C. li 15 8631 7 Composition according to any of the preceding claims, characterized in that R contains on average 12-18 carbon atoms. Composition according to any of the preceding claims, characterized in that the weight ratio between the ketene dimer and the stabilizer is 1: 0.25 - 1: 1. Composition according to any of the preceding claims, characterized in that a polymeric cationic dispersant is present. Composition according to claim 7, characterized in that the dispersant is selected from water-soluble alkylene polyamine epichlorohydrin resins and Poly (diallylamine) epichlorohydrin resins. Composition according to claim 7 or 8, characterized in that the weight ratio between the ketene dimer and the dispersant is 1: 0.5 - 1: 1. Composition according to any of the preceding claims, characterized in that at least one surfactant is present. Wherein R is an alkyl, alkenyl, aryl or alkaryl group containing from 8 to 24 carbon atoms, the composition also containing water-soluble stabilizing agent selected from the group of gelatin, tristearine, gum arabic, sugar, ethyl cellulose, carboxymethyl cellulose , polyacrylamides, water-soluble silicates, polyethers, polyesters, polyamides, starches and polyvinyl alcohol, and the composition is prepared such that the (a) ketene dimer of the above-defined formula and the water-soluble stabilizer is formed into an aqueous dispersion and (b) the the aqueous dispersion is dried, forming a homogeneous particulate solid dispersible in water. Composition according to claim 10, characterized in that the surfactant is selected from the group of salts of naphthalene formaldehyde sulfonate condensate - esters of polyoxyethylene sorbitan and salts of lignosulfone. . 25 acids. 12. Composition according to claim 10 or 11, characterized in that the amount of the surfactant is 0.3 - 3.5% by weight of the amount of the ketene dimer. Use of an aqueous dispersion according to any one of claims 1 to 12 as a sizing agent in a process for making glued paper or glued cardboard.