CH630660A5 - Inversion process for the preparation of papermaking glue from reinforced rosin - Google Patents

Description

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CLAIMS 1. Reversing process for the preparation of a stationery glue from a fortified rosin, during the implementation of which molten fortified rosin and water containing a dispersing agent are previously mixed in order to '' establish an emulsion in which the molten fortified rosin is the continuous phase while the water is the dispersed phase, after which the emulsion is inverted by the addition of water in order to establish an emulsion in which the water is the continuous phase while the fortified rosin is the dispersed phase, which process is characterized in that one uses as dispersing agent one or more compounds soluble in water and which provide in solution one or more anions representable by the following formula:

o o Il II 0 (CH2CH20) nCCHCH2C0

so3-

(I)

wherein R is a normal or branched chain alkyl radical having from 4 to 18 carbon atoms, and n is an integer from 4 to 25.

2. Method according to claim 1, characterized in that the anion is derived from a water-soluble compound containing the anion and a suitable cation allowing a substantial dissolution of the compound in water.

3. Method according to claim 1, characterized in that, in the anion, R is a nonyl radical, and n has an average value equal to 9.5.

4. Method according to claim 2, characterized in that the cation is chosen from the group consisting of sodium, potassium and ammonium.

5. Method according to claim 3, characterized in that the cation is chosen from the group consisting of sodium, potassium and ammonium.

6. Inverted glue, characterized in that it is prepared by implementing the method according to claim 1.

7. Inverted glue according to claim 6 prepared by implementing the method according to claim 2.

8. Inverted glue according to claim 6, prepared by implementing the method according to claim 3.

9. Inverted glue according to claim 6, prepared by implementing the method according to claim 4.

10. Inverted glue according to claim 6, prepared by implementing the method according to claim 5.

The question of the internal gluing of paper with rosin is dealt with in Casey's work, "Pulp and Paper", 2nd edition, Volume II: "Papermaking", Chapter XIII, pages 1043-1066.

On page 1048 of the above-mentioned work, Casey deals with the question of a fortified rosin-based glue and indicates that fortified rosin-based glues are prepared by reacting maleic anhydride or other dienophile substances. with rosin to increase the number of carboxyl radicals. Casey also specifies that a typical fortified glue can contain approximately 1 to 30% of maleopimaric acid anhydride.

On page 1047, Casey, under the chapter heading "Free Rosin Size" (glue based on free rosin), specifies that the relative merits of a glue with a high content of free rosin and a glue with a low content of rosin free have been the subject of controversy for many years, but it is now more or less generally recognized that the application of a glue with a high content of rosin free results in better gluing and allows the use of less alum.

On page 1050, under the title “Protected Rosin Size”, Casey specifies that, thanks to the use of a protective colloid, it is possible to prepare a very stable adhesive which can contain a concentration of rosin as high as 90% (free rosin). On page 1051, Casey describes the Bewoid process for the preparation of a glue with a high free rosin content and specifies that the Bewoid glue, as it is usually prepared, contains approximately 90% of free rosin dispersed in a small amount of rosin soap and stabilized by the presence of about 2% casein or other protein. Casein serves as a protective colloid to prevent the magnified rosin particles from smelling, thereby keeping them in a state of fine division.

Casey also specifies that the Bewoid process involves the mechanical subdivision of rosin in the presence of approximately 1 to 2% of sodium hydroxide and approximately 2% of casein. The rosin is heated and subjected to mechanical shear stress until it is subdivided into small particles. A small proportion of caustic soda (1.6 parts per 100 parts of rosin) is then added to the rosin in order to partially saponify it, after which casein is added (2.0 parts of casein dispersed in 0.2 parts caustic substance) to stabilize dispersed rosin particles. The dissolved casein is introduced into the molten rosin and vigorously agitated, after which a small proportion (0.2 part) of additional caustic substance is added, or the hot molten mass of rosin is injected into water containing casein. Finally, water is added to produce a dispersion containing about 45% solids and used in this form. This method is sometimes referred to in the art as an "inversion process for the preparation of rosin glue", and the rosin-based glue thus produced is called "inverted glue".

Using the inversion process, Mashburn, in his US Pat. No. 2,393,179, describes the preparation of a glue based on free rosin using a non-alkaline dispersing agent, such as a sulfonated higher fatty alcohol, to the instead of sodium hydroxide. The rosin is melted and the desired proportion of dispersing agent is added thereto with sufficient stirring to form a homogeneous melt. A substantially neutral or slightly acidic aqueous solution or dispersion of a protective collar-45 (such as casein) is then gradually added while stirring rapidly so that a paste-type dispersion with high content is produced. solid substances which is then diluted with water to a solids content between 40 and 60% by weight.

50 Casey, on pages 1051 and 1052, deals with the Prosize process for the production of a protected adhesive with a high content of free rosin. The rosin particles are prevented from growing and forming aggregates; for this, a surface-active protein such as soy protein is added.

55 The German patent No. 1 131 348 specifies that adhesives based on free rosin are dispersions of non-saponified resin acids and containing a certain percentage of rosin soap. The dispersions are prepared by the inversion process. Most of the time, they are used with a free rosin content of 60 to 95% and they contain, in addition to rosin, emulsifiers and auxiliary rosin stabilizers such as stearates, triethanolamine, casein and waxes.

German Patent No. 1,131,348 further indicates that, to date, 65 fortified rosins have not been shown to be suitable for the preparation of dispersions since they mostly have too high melting points, have a tendency to crystallize, or to form, during dispersion, fines

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crusts which show sedimentation phenomena. The same patent describes and claims a stationery glue and a process for the preparation of a stationery glue in the form of an aqueous dispersion with a high content of free rosin from fortified rosin, which process is characterized by that the fortified rosin is mixed with fatty acids, mixtures of fatty acids, and / or naphthenic acids at elevated temperatures, the dispersion being carried out in a known manner. The process used in this patent is the inversion process. 10

US Patent No. 3,565,755 describes a stable, substantially homogeneous aqueous suspension of rosin-based material in a state of fine subdivision. The rosin material can be either only fortified rosin or a mixture of ordinary rosin and fortified rosin. A very small proportion of the rosin material is saponified and functions as a dispersing agent for rosin particles. This composition, which essentially comprises rosin material, saponified rosin material, and water, is used for sizing paper. The adhesive described in this patent No. 3,565,755 is an adhesive with a high content of free rosin because it contains only a very small proportion of material based on saponified rosin. In addition, it has good stability (long shelf life in stores) and does not require the use of stabilizers which have been used until now to prepare stable adhesives with high rosin content, stabilizers such as, for example, casein and soy protein.

During the implementation of the process described in the aforementioned US Patent No. 3,565,755, a material such as a rosin salt or a fortified rosin salt, or an alkaline substance such as sodium hydroxide, is dissolved in water. The resulting aqueous solution is mixed with a solution prepared with an organic solvent immiscible with water, such as benzene, in which fortified rosin has been dissolved. The resulting mixture is homogenized in order to produce a stable emulsion, then the organic solvent is separated from it in order to obtain a stable aqueous dispersion.

Australia patent application No. 69375/74, filed from May 24 to 24, 1974, describes a process for the preparation of an essentially stable aqueous dispersion of a rosin-based material, usable for sizing cellulosic stationery fibers, which process consists in homogenizing, under a pressure between about 140 kg / cm2 and about 560 kg / 45 cm2 and at a temperature between about 150 ° C and about 195 ° C, an unstable aqueous dispersion containing, by weight, at least 5% of solids, said solids essentially consisting of a mixture containing, by weight, from 0 to approximately 95% of rosin and from 100% to 5% of a reaction product of the adduct type of rosin and d 'an acidic compound containing the radical -C = CC— O, the

III

proportion of said compound with an acidic character forming the adduct being between approximately 1% and approximately 20% of the weight of the 55 total solids, said method being characterized in that it is carried out in the presence of an anionic dispersing agent. This anionic dispersing agent may be a material based on saponified rosin, a sodium alkylbenzenesulfonate, a sodium naphthalenesulfofan, sodium aurylsulfate, and the ammonium salt of the sulfate-type ester of an alkylphenoxy (polyethyleneoxy). ethanol.

Sweden patent application No. 7410018-1 describes a practically stable aqueous dispersion, essentially consisting of water, a rosin type material and, as stabilizer for the rosin type material, an alkali metal alkyl benzenesulfonate present in a sufficient proportion to stabilize said rosin-like material. The dispersions are prepared by passing, through a homogenizer, a mixture prepared with the components.

US Patent No. 3,906,142 describes an agent for sizing paper without the use of aluminum sulphate, and which comprises a stable aqueous dispersion of fortified rosin (fortified by reaction with an α, ß-unsaturated carboxylic acid or with an anhydride of such an acid); a protective colloid, such as casein; and a volatile base, such as ammonia; at least 90% of said fortified rosin being non-saponified.

The procedure used in the aforementioned US Patent No. 3,906,142 is the inversion process for preparing an adhesive and consists in melting fortified resin in a container equipped with stirring and heating means. In a separate container, a dispersing and stabilizing agent is prepared by dissolving a measured amount of a protective colloid, such as casein, and a measured amount of a volatile base, such as ammonia, in water. The following elementary operation for the manufacture of the sizing agent consists in rapidly adding, to the molten rosin, the dispersing and stabilizing agent, previously prepared, with very vigorous stirring of the mixture during and after the addition. The solids content of the resulting aqueous rosin dispersion is then adjusted by adding a calculated amount of water to it.

In accordance with the present invention, there is provided an inversion process for the preparation of a stationery glue from fortified rosin, in which the use of protective colloids, such as casein, which have up to present resorted to when implementing an inversion process, is not essential.

According to the present inversion process, molten fortified rosin and water containing a dispersing agent are first mixed to establish an emulsion in which the molten fortified rosin is the continuous phase while the water is the dispersed phase. , after which the emulsion is inverted or inverted by the addition of water in order to establish an emulsion in which the water is the continuous phase while the fortified rosin is the dispersed phase. The improvement lies in the use, as a dispersing agent, of a water-soluble compound which provides in solution an anion which can be represented by the following formula:

O O

R

/ ^

0 (CH2CH20) „CCHCH2C0 I

so, ~

50

wherein R is a straight or branched chain alkyl radical having from 4 to 18 carbon atoms; and n is an integer from 4 to 25. The value of n, as used here, is an average value because, during the implementation of the process for the preparation of the dispersing agents, one obtains, following the condensation reaction, condensation products of ethylene oxide in which the length of the chain varies. As examples of radicals R, mention may in particular be made of butyl, isobutyl, pentyl, isopentyl, hexyl, isohexyl, octyl, nonyl, dodecyl, tetradecyl, hexadecyl and octadecyl.

The aqueous suspensions prepared by carrying out the process according to the invention can comprise, by weight, from approximately 5% to approximately 70%, and preferably from approximately 10% to approximately 55%, of fortified rosin or of a mixture based on fortified rosin (fortified rosin mixed with non-fortified rosin and / or with a diluent, as described below); from about 1% to about 10%, and preferably from about 2% to about 8%, of a dispersing agent based on the weight of the fortified rosin or the fortified rosin mixture; the rest, or 100% complement, being water.

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The rosin which is used to prepare the fortified rosin used during the implementation of the invention can be any of the different types of rosin being commercially available and such as wood rosin, gum rosin or gemstone, rosin of tali oil and mixtures of at least two such substances, in the raw state or in the refined state. Rosins which tend to crystallize can be treated, at elevated temperatures, with formaldehyde or paraformaldehyde in the presence of an acid catalyst such as, for example, ptoluenesulfonic acid, in a manner well known to those skilled in the art. Rosin treated with formaldehyde can therefore be used to prepare fortified rosin, and such treated rosin is included in the scope of the term "rosin" as used in the present description and in the following claims.

The fortified rosin used is the reaction product of the adduct type of rosin and of an acidic compound containing the radical> C = C-C = O and is obtained by reacting I I

rosin and the acidic compound at elevated temperatures, usually between about 150 ° C and about 210 ° C.

The proportion used of compound with an acidic character will be that making it possible to obtain a fortified rosin containing from approximately 1% to approximately 12%, and preferably from approximately 4% to approximately 9%, by weight, of compound to acid character engaged in an adduct, based on the weight of the fortified rosin. Procedures for the preparation of fortified rosin are described in US Pat. Nos. 2,628,918 and No. 2,684,300. 30

As examples of compounds of an acidic nature containing the radical> C = Ç-Ç = 0 and which can be used to prepare fortified rosin, mention may be made in particular of a, β-unsaturated organic acids and their available anhydrides, and more particularly the following compounds: fumaric acid, maleic acid, acrylic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride. The preferred acid for preparing an adduct is fumaric acid. It is also possible, if desired, to use mixtures of acids to prepare the fortified rosin. It is also possible, if desired, to use mixtures of different fortified rosins. Thus, for example, to prepare the inverted adhesives according to the invention, it is possible to use a mixture of the rosin adduct with acrylic acid and the adduct with fumaric acid. 45

Fortified rosin can be diluted, if desired, by using diluents known to be useful for such purposes and such as waxes, more particularly paraffin wax and microcrystalline wax; hydrocarbon resins, including those derived from petroleum hydrocarbons and terpenes, and the like. Such dilution is achievable by mixing with the fortified rosin, either in the molten state or in solution, up to about 100% by weight, based on the weight of the fortified rosin, of the diluent for the fortified rosin. If it is a question of incorporating a diluent into the fortified rosin 55, the proportion by weight of diluent used preferably represents from about 30% to about 50% of the weight of the fortified rosin.

It is also possible to use, for implementing the invention, mixtures of fortified rosin and unfortified rosin as well as mixtures of fortified rosin, diluent and non-fortified rosin.

Mixtures of fortified rosin and unfortified rosin can comprise from about 25% to about 99% fortified rosin and from about 75% to 65 about 1% unfortified rosin. Mixtures of fortified rosin, rosin and rosin diluent can comprise from about 25% to 49% fortified rosin,

from about 5% to 50% of unfortified rosin, and from about 1% to 50% of diluent for fortified rosin.

If rosin (i.e., unfortified rosin) is mixed with the fortified rosin, it can be any of those usable for the preparation of fortified rosin, and a list of which is given above. It is also possible to use, if desired, partially or practically completely hydrogenated rosins, and polymerized rosins.

The dispersing agents used to prepare the dispersions according to the invention are water-soluble compounds, which can be represented by the following formula:

O O

0 (CH2CH20) nC CHCH2C — O- M + (i)

SO,

M +

in which R and n are as defined above.

In formula (I), M + is any suitable cation capable of allowing considerable dissolution of the dispersing agent in water.

Preferably, M + is an alkali metal ion such as potassium, sodium, lithium and cesium; ammonium (NH4 +); and mono- (hydroxyethyl) ammonium. An M + can be the hydrogen ion (H +), if desired.

Water-soluble dispersing agents can be prepared, using known methods, which can be represented by formula (I). Thus, for example, ethylene oxide is condensed with an alkylphenol, such as octylphenol, using well known procedures to obtain a condensation product which can be represented by the following formula:

JD- 0 (CH2CH20) nH

As already indicated above, the value of n is an average value, since condensation products of ethylene oxide having various chain lengths are obtained as a result of the condensation reaction. . The condensation product is then allowed to react with maleic anhydride or maleic acid, and the resulting reaction product is itself allowed to react with a water-soluble sulfite, such as sulfite. sodium, after which a water-soluble salt is obtained, which can be represented by formula (I). Sodium salts of the sulfosuccinate esters of ethylene oxide condensation products with alkylphenols are commercially available; a particular example is the product sold under the brand name "Aerosol Al 03".

During the implementation of the method according to the invention, a known amount of fortified rosin, together with any suitable diluent desired and / or unfortified rosin, is heated until melting in a container equipped with stirring and heating means in order to constitute a molten resinous mass (molten resin). The temperature of the molten resin is usually between about 90 ° C and about 160 ° C. If it is a question of mixing a melting point based diluent with the fortified rosin, the temperature of the molten mixture can be lower than 90 ° C.

A solution of the dispersing agent in water is added to the molten resin, while continuously agitating the molten resinous mass, in order to form an emulsion in which the water constitutes the dispersed phase while the molten resin constitutes the phase keep on going. The proportion of dispersing agent in the aqueous solution should be of sufficient value

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to allow the supply of a quantity of dispersing agent, ex- Example A

award-winning by weight, based on the weight of the molten resin, the present example illustrates the preparation of rosin form-

taken between about 1% and about 10%, and preferably between tified with fumaric acid. At a temperature of about 2% and about 8%. The proportion of water used at this 200 ° C., an adduct of 8 parts of fumaric acid is formed with stage corresponds to the proportion sufficient to establish a 92 parts of rosin of tali oil. Fumaric acid emulsifies as described above, having a content by weight dissolved in molten rosin and reacts with it, and there are total solids between about 70% and 86%, depending on the form of rosin fortified with fumaric acid. nature of the particular dispersing agent used and depending on its con- centration after practically all of the fumaric acid has reacted. with rosin, the fortified rosin is cooled to

Then, stirred vigorously, at room temperature (about 21 ° C).

Additional amount of hot water (reversal water) to a Hereinafter are given different examples, of course non-temperature of about 70 ° C. For a ratio of water to the limiting, intended to illustrate the methods of implementation of sine equal to approximately 30:70, the emulsion is reversed, the water becoming the invention. All the quantities expressed in “parts” and continuous phase while the resin becomes the dispersed phase. all the proportions expressed in percentages must be obtained. On cooling, the resin solidifies and a soft weight is obtained, unless otherwise indicated.

aqueous dispersion of finely divided resin particles. The resin particles can be either colo particles. Example 1

fortified phane, or particles of a mixture based on colo- We melt and heat up to 145 ° C, in a container

fortified phane as described above. The aqueous dispersion stainless steel baffles, 100 parts of the fortified resin can be diluted to a lower solids content, if it is by fumaric acid prepared in the manner described as desired, by the addition of 'water. Example A. To the stirred molten fortified rosin, the following is added,

It has been found that dispersions according to the invention have, over a period of 5 minutes, about 21 times good stability at a pH between about 3.0 and parts of a solution at 23, 3% dispersant "Aerosol Al03" about 5.5. The pH can be adjusted by adding an alkali from to distilled water which has been heated to 95 ° C. Said sodium hydroxide, inversion water or persant "Aerosol Al 03" is preferably the disodium salt of nenylphenol aqueous solution of dispersing agent, in a proportion which is ethoxylated (9.5 moles of ethylene oxide per mole of nonylphé-so as to bring the pH of the aqueous dispersion to the desired value (noi) in the form of half-ester of sulfosuccinic acid. A

Those skilled in the art will readily understand that the process of considerable amount of water evaporating during the addition of the invention can be carried out either in a solution container of the surfactant. The temperature of the mixture,

open, under atmospheric pressure, either under pressure, in 30 after this addition is completely completed, is equal to a closed container. 85 ° C. To the stirred mixture, an additional quantity of 20 parts of hot water (at 90 ° C.) is added, and thus the temperature is obtained, as already indicated above, in an emulsion of the water type. in the smooth, white-crimson resin, the molten resin (fortified rosin or soft base mixture, having a solids content approximately equal to fortified rosin) is advantageously between- 80%. Then added, with vigorous stirring, at about 90 ° C and about 160 ° C. If the process is carried out over a period of one minute, 70 parts of water under atmospheric pressure and if the initial temperature of the boiler at 90 ° C, which causes the inversion of the emulsion and its resin is higher than 100 ° C, the temperature will drop during transformation into an emulsion of the resin type in water, that the addition of the aqueous solution of dispersing agent because one cools quickly up to 30 ° C. The aqueous dispersion of a partial evaporation of water. If the resulting compound is prepared, it has a solids content of 51.4%, has a closed container and under a bluish white appearance vapor pressure, passes completely through a sieve. water, which has the effect of delaying the evaporation of water, is standardized No. 100 (with square openings measuring 0.149 mm of can maintain the temperature at a value greater than 100 ° C. side), and has excellent storage stability. This can be varied over a wide range the rate of addition product is advantageously usable as papaya glue-aqueous solution of dispersing agent and water inversion, 45 rie.

and the choice of the operating conditions is the competence of an Example 2

specialist. However, normally, the apparatus used in the present example should increase the rate of reversing water and speed up the agitation when over three precision pumps, two mixers arranged in series, comes the point inversion to ensure rapid inversion and two pressure receptors, auxiliary complete arrangements to form the dispersion of the resin type in water. The pressure control and adjustment, and the heated pipes temperature at the reversal point is between approx. Connecting these different elements of the apparatus, between 70 ° C. and approximately 150 ° C., and preferably between approximately tali oil rosin, fortified with 1 fumaric acid

90 ° C and around 130 ° C. that and prepared as described above in the example

A, is heated to about 140 ° C and is injected, using We can also implement the process in two stages at 55 from a pump, up to a first mixer, which is hand-bringing the resin melt and the hot aqueous agent solution kept at 125 ° C, at a flow rate of 4.12 parts per minute, where it is dispersed to a mixer in order to form the dispersion of the mixture with a solution at 11.8 % of dispersing agent "Aerosol type water in the resin. Subsequently, the A103 "is brought under distilled water heated to 80 ° C., which is injected in the form of separate streams, the dispersion of the water type in the into the said first mixer using a a resin and the inversion hot water up to a second mixer 60 flow rate of 1.66 parts per minute, which has the effect of establishing a maintained at a temperature between about 70 ° C. and emulsion of the type water in the resin containing 70% solids. 150 ° C until reversal occurs. This emulsion is then collected and discharged into a second mixer, from the second mixer, the resulting aqueous dispersion. maintained at 105 ° C, where it is mixed with distilled water

By implementing the method according to the invention, heated preparations are prepared up to 90 ° C. which are pumped into said second stable dispersions, of the resin in water type. The particles 65 mixer at a flow rate of 3.5 parts. Per minute. It forms thus constituting the dispersed phase are relatively small, to an emulsion of the resin in water type having a content of so-

maximum about 10% of the particles measuring more than about 45% lides and which is then rapidly cooled to a 0.4 micron. temperature below 50 ° C.

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Example B

A rosin of tali oil, fortified with fumaric acid, is prepared by operating as described above in Example A, except that approximately 7.5 parts of d fumaric acid and 92.5 parts of rosin from tali oil. The rosin of tali oil fortified with fumaric acid thus obtained has an acid number equal to 215 and contains approximately 7% of combined fumaric acid.

Example 3

Melt and heat up to 134 ° C., in a stainless steel baffle container, 200 parts of rosin fortified with fumaric acid prepared as described above in example B. Fortified rosin, melted and stirred, 40 parts of a 20% solution of dispersant "Aerosol A103" are added over a period of 5 minutes

in distilled water which has been heated to 95 ° C. A considerable amount of water evaporates during the addition of the surfactant solution. The temperature of the mixture, after this addition is completely finished, is 106 ° C. An additional 80 parts hot water (90 ° C) is added to the stirred mixture to give a smooth, creamy white, water-in-resin emulsion containing approximately 80% solids. 180 parts of hot water at 90 ° C. are then added thereto, in one minute and with vigorous stirring, which causes the emulsion to invert, and the emulsion is rapidly cooled to 30 ° C. of the resin in water type thus obtained, which has a solids content of 45.9%.

The dispersion of Example 3 is used to make the surface bonding of sheets of unglued paper made with 50% bleached softwood kraft pulp and 50% bleached hardwood kraft pulp having a degree of fiber freedom, determined according to Canadian Standardization, equal to 5500. The sheets of paper are prepared on a pilot paper machine, at a pH of 4.5 and with the addition of 2.5% alum. After ~ the application of the dispersion on the surface of the leaves, they are dried on a drum and allowed to age for 24 hours before carrying out the tests. Three sizing rates are applied, as specified in Table I below. Hercules sizing tests reveal the good results of such sizing operations. These test data are also shown in Table I below.

15 Table I

Glue application rate 1 (based on the dry weight of the paper sheet)

2C

0.07 0.14 0.28

Gluing test

Hercules

(seconds)

41,147,290

It should also be emphasized that any specialist, having read the description of the invention above, can easily imagine and use many other variants and modifications of the specified embodiments, and this without thereby departing from the spirit or the scope of said invention.

VS