FI88814B - FOERFARANDE FOER BEKAEMPNING AV HARTS - Google Patents

Abstract

A method for the control of pitch in an aqueous system used in pulp or paper making is disclosed which comprises adding to the system, or to the pulp making or paper making machinery, a water soluble polymer derived from (a) an epihalohydrin, a diepoxide or a precursor of an epihalohydrin or diepoxide, (b) an alkyl amine having a functionality with respect to an epihalohydrin of 2 and (c) an amine which has a functionality with respect to an epihalohydrin greater than 2 and which does not possess any carbonyl groups.

Description

1 88814

The present invention relates to resin control in connection with the production of pulp and paper.

"Resin" is known to accumulate in papermaking and also in pulp production, causing significant difficulties. The word "resin" is used to describe sticky substances in the manufacture of paper which come from the wood used to make the paper. Today, with the increasing use of recovered paper, the word "resin" is also used as a general term for all substances that are soluble in organic solvents but not water, e.g., ink or glue contained in recovered paper. Resin can accumulate in various parts of the system. For example, it can clog the felt and thus prevent dewatering on the paper web. In addition, it can adhere to wires or drying cylinders, causing holes in the paper. Deposits can also form at any of the early stages of the papermaking process. When these deposits come off, the paper may become defective in the form of a stain or hole. Defects such as this can make the paper even so weak that the paper breaks during manufacture, leading to unwanted production downtime.

Several agents have been used to eliminate these difficulties. Such agents include treatment with an inorganic agent such as talc and anionic dispersants. However, ordinary dispersants may be ineffective in a closed system because "resin" may have accumulated in it. The resin particles in such systems must be removed from the water system in a controlled manner so that they do not accumulate in the felt or rolls or in the piping of the papermaking machinery, for example. The effectiveness of these products has been found to be limited and the development of treatment methods necessary.

2,88814 In accordance with the present invention, it has now been found that certain water-soluble polyquaternary amines are particularly effective for this purpose. The invention comprises a method by which resin control of an aqueous system used in the manufacture of pulp or paper can be performed, including adding a water-soluble polymer to the system or machinery used in the manufacture of paper or pulp. The water-soluble polymer is prepared from (a) an epihalohydrin, a diepoxide or a precursor of an epihalohydrin or diepoxide, (b) an alkylamine having two functionalities with respect to epihalohydrin, and (c) an amine having less than two functions with respect to epihalohydrin. The essential features of the method appear from the appended claims.

A particular feature of the products used in this invention is that they can combine with a dissolved anionic substance derived from the wood used to make paper or pulp, thus providing a method for removing these anionic substances while reducing the concentration of such substances in the process water. Water-soluble anionic substances are released from wood during pulping. These components have a negative effect on papermaking in many ways: they reduce the efficiency of many products used in the papermaking process that affect the properties of the paper. Examples of these additives are adhesives, wet and dry strength agents and paints. Anionic solutes also reduce the effectiveness of retention aids. They set a limit on the amount of substance added to the water system and can also degrade paper quality, such as strength. Reference is made to the TAPPI paperma-kers Conference, 1979, pp. 49-66, where the role of anionic solutes is discussed in more detail.

Component (a) is preferably an epihalohydrin, especially epichlorohydrin or epibromohydrin, but dihalohydrins, preferably dichlorohydrins or dibromohydrins having from three to twenty, especially from three to ten, carbon atoms per molecule may also be used. Typical useful dihalohydrins are: 3 8881 4 CH C1CHC1CH OH 2 2 CH C1CH (OH) CH Cl 2 2 2 CH CHC1CHC1CH OH 3 2 CH CHC1CH (OH) CH Cl 3 2 CH CH CHC1CHC1CH OH 3 2 2 CH3CHC1CHC1CH (OH) CH3 CH CH CHC1CH (OH) C1 3 2 CH CH CH (OH) CHC1CH Cl 3 2 2 CH CHC1CH (OH) CHCl3 3 and

CH

I 3 CH CCHC1CH Cl 31 2

OH

CH

CH ClicHCICH 2 I 3

OH

CH

CH (OH) i-CHCl 1

2 il

With respect to component (b), the aiamine may be a compound containing two tertiary amino groups, such as Ν, Ν, Ν ', Ν'-tetramethylethylenediamine. A detailed preparation of the products derived from components (b) and (a) is given in UK-A-1 486 396. However, component (b) is preferably diacylamine, the alkyl groups of which each individually contain from one to three atoms. Dimethylamine is particularly preferred.

As previously mentioned, component (c) is an amine having a functionality with respect to epihalohydrin greater than 4,88814 two and does not contain carbonyl groups; it can therefore act as a branching agent. The use of a branched polymer has proven to be an important factor in preventing the formation of resin layers by means of a polymer, as can be seen from the comparative experiment below. The primary amino group is capable of reacting with three molecules of Epic 1ohydrin such that the functionality of a single primary amine is three.

Similarly, the functionality of a simple secondary amine may be two. The functionality of a simple tertiary amine may be one. Component (c) is usually ammonia, a primary amine, a primary alkylene polyamine containing from 4 to 25, preferably from 4 to 12, carbon atoms and at least one, preferably from 1 to 6, primary groups per molecule, comprising both polyglycolamines and aromatic and heteroaromatic diamines. , but not polyamidamines, as they contain carbonyl groups. Preferred substances are ammonia, diethylaminobutylamine, dimethylaminopropylamine and ethylenediamine, the latter two being particularly preferred.

If desired, the polymer can also be derived from a component which generally has the ability to act as a chain end covering. These substances are generally also amines or other substances which react with epichlorohydrin and have less than two functionalities and which contain another functional group or fatty chain containing, for example, at least 12 carbon atoms, such as a simple tertiary amine such as trialkylamine, especially trimethylamine or hydroxy amine, typically triethanolamine or a fatty amine such as octadecylamine.

The polymers used in the invention can be prepared by first reacting components (a) and (b) with each other to form 11 binders, which are reacted with the fourth component of component (c), if desired. Suitable polymers for use in this invention include , the coupling agent of which is made of epichlorohydrin and dimethylamine, which are reacted with ethylenediamine and, if desired, also trimethylamine, trethanololamine or octadecylamine.

Polymers can also be prepared by reacting a mixture of components (b) and (c) with component (a). The preferred raw materials for such a process are the same as those mentioned above.

The reaction is generally carried out in a liquid medium at a reaction temperature of typically 5 to 125 ° C, preferably 30 to 95 ° C.

A suitable equivalence ratio between component (b) and component (c) is 1: 0.009 to 1.0, preferably 1: 0.02 to 0.5. The equivalent ratio between component (a) and components (b) and (c) can vary widely depending on the amount and quality of component (b). The ratio between component (c) and component (a) and component (b) should generally be selected together so that the viscosity of the liquid polymer solution is at least 20 cps at a dry matter content of 50%. The ratio is typically 1: 0.22-2.5 and preferably 1: 0.25-1.3. The reaction can generally be continued to the desired viscosity, and thus to the molecular weight, although the acid can be used to lower the pH and thereby complete the reaction. A pH of 1-7.5, especially 2-6.5, is generally considered to be the preferred pH of the final solution.

The upper limit of viscosity is not critical if it is uniform and when the solution is to be processed, the upper limit is normally about 2000 cps.

Further details on useful polymers and their preparation are provided in, inter alia, UK-A-2,085,433, U.S. Pat. No. 3,855,299 and U.S. Patent Renewal No. 28,808, and for some polymers in the article "Poly-electrolytes for Water and Wastewater Trea tmen t, toi. W. L.

6 «8814

Schwoyer, CRC Press Inc, pages 26-35. A particularly preferred polymer for use in this invention is prepared by reacting ethylenediamine with a precondensate of dimethylamine and epichlorohydrin, the product of which is reacted with triethanolamine to give a water-soluble reaction product. Another preferred product is prepared by reacting a mixture of dimethylamine and ethylenediamine or dimethylaminopropylamine with Epichlorohydrin to give a water-soluble product.

The polymer is usually added to the liquid system with the pulp containing the pulp, but it can also be added to different parts of the system depending on the problem in question.

The amount of polymer required will, of course, depend to some extent on the wood and other materials used to make the pulp. In addition, certain polymers tend to circulate in the system, thus requiring a lower dosage. A suitable amount of polymer based on the weight of the liquid medium is generally 0.1 to 20 ppm, preferably 1 to 10 ppm. This normally corresponds to an addition of 100 to 2,000 grams, preferably 100 to 1,000 grams, of polymer per ton of fiber. However, in cases where the polymer is needed to neutralize the anionic solutes, larger amounts of polymer are required, normally 1,000-50,000 grams, preferably 1,500-15,000 grams, per ton of fiber depending on the fiber manufacturing process (see e.g. Progr. Colloid & Polymer Sci. 65, 251-264 (1978), which indicates the amounts of anionic substances that may be present). Fibers made by a mechanical process generally require a higher dose than fibers made by a chemical process. Of course, it is possible to neutralize only a part of the total amount of dissolved anionic substances. In such cases, amounts as small as 10 g per tonne of paper can be effective.

7 88814

Sometimes it may be advantageous to spray the reaction product used in this invention on a specific part of a pulp or papermaking machinery, such as a wire or press felt. In these cases, it is preferred to dilute the polymer with water, generally to less than 10% by weight, preferably 1 to 5% by weight.

In some cases, it is common to add the polymer together with the biocide. Examples of suitable biocides are biocides belonging to the following classes: (i) a substituted 5- or 6-angle heterocyclic compound in which the heteroatom or atoms are or are nitrogen, oxygen or sulfur and the substituent is an alkyl group, a keto group or a hydroxyl group or a hydrogen atom, such as compounds of the formula:

S - R

CH - Nx /

3 V

^ 0 wherein R represents hydrogen or chlorine. A mixture of these two isothiazolones is available as a commercial product with a chloro-substituted compound to unsubstituted ratio of 2.66: 1; (ii) phenol or chlorophenol such as pentachlorophenol; (iii) an amine or amide comprising 2,2-dibromo-3-nitropropylpropane; (i v) organic cyanide or thiocyanate, in particular m e ty 1 e e n i b i s (t i o sy a n a a t i t); (v) a sulfone, including sharks, especially hexachlorodimethyls; e R8814 (vi) straight chain aliphatic aldehyde, especially glutaraldehyde; (vii) triazine, in particular thio- and / or amino-substituted substituents; (viii) bis-bromoacetoxybutene; and (ix) dithiocarbamate, especially monomethyl, dimethyl, monoethyl and diethyl derivatives, typically in the sodium salt form.

The polymer is generally compatible with additives used in the manufacture of pulp and paper, such as starch, for example potato or corn starch, titanium dioxide, an antifoam, such as a fatty alcohol, an adhesive, an abietic acid-based solvent, a resin, and a wet strength resin such as, if neutral, epichlorohydrin polyamide or, if acidic, melamine or urea formaldehyde with the resin.

Knowing the exact pH of the system is not important, as the efficiency of the polymer does not change significantly with pH variations.

Certain of the polymers used in this invention are commercially available, generally in 40-50% liquid solutions. The combinations used in this invention contain 1-70%, especially 10-30%, of polymer by weight.

The following examples illustrate the invention in more detail: Example 1

183.5 g of 32.7% dimethylamine and 270 g of water were placed in a reaction vessel equipped with a reflux condenser, a mechanical stirrer and a thermometer. 76.04 g of 36% hydrochloric acid were added while maintaining the temperature at 35 ° C with cooling. 208.12 g of epichlorohydrin was added over 30 minutes. Cooling was continued so that the temperature did not rise above 40 ° C. This temperature was maintained for two hours to obtain a thick solution containing a so-called "coupling agent". A liquid solution of 176.9 g of coupling agent was heated to 60 ° C using the same equipment. 5.94 g of ethylenediamine were added dropwise over 30 minutes. The temperature was maintained at 60 ° C for one hour.

o

The reaction mixture was heated to 90 ° C and 32.48 g of 30% trimethylamine was added over ten minutes; 90 ° C was maintained for two hours, after which the reaction mixture was cooled to room temperature. The total solids in this reaction mixture was 40.7%.

Example 2 Using the apparatus described in Example 1, 68.81 g of a 32.7% dimethylamine solution and 121.4 g of water were added to a mixture of 25.35 g of 36% o hydrochloric acid. The temperature was kept below 35 ° C by cooling. 83.25 g of Epichlorohydrin were added so that the temperature remained at 40 ° C. This temperature was maintained for one hour. The reaction mixture was heated to 60 ° C and 7.5 g of ethylenediamine was added over 15 minutes at 60 ° C. This temperature was maintained for another 30 minutes. The reaction mixture was heated to 90 ° C and 37.25 g of triethanolamine was added dropwise over 30 minutes. The temperature was maintained for another two hours to complete the reaction. The total amount of solids was 44.6%.

Example 3

The products prepared in Examples 1 and 2 were mainly evaluated by Ch. E. Farley at the 1977 TAPPI Papermakers Conference, according to the method described on pages 23-32. This is based on the TAPPI Standard Method RC324, a valued method for estimating the tendency of resin to deposit. A standard resin solution was prepared according to the above reference. A synthetic resin emulsion / dispersion was prepared by adding one liter of deionized 50 ° C water to the synthetic resin to a concentration of 1200 ppm.

Potassium chlorine solution was added to achieve a hardness of 340 ppm expressed as umcarbonate. The pH was adjusted to 8.0. In order to survive the evaluation of the products as a pesticide, the products were added to the mixture to such an extent that the polymer concentration corresponded to the values specified in Table I. The tendency of the resin to form deposits was evaluated according to the above method. Each test lasted five minutes. The results are shown in Table I (mg of resin layer soil).

Table

Product Concentration (ppm) Resin deposition (mg) zero - 280 Example 1 2 252 Example 1 10 2 Example 2 2 255 Example 2 10 28

Comparative Example 1

For comparison, an aminoplast resin was prepared from U.S. Patent 3,582,461, essentially as in Example III.

84 g (1 mole) of dicyanamide amide, 196 g (2.4 moles) of a 37% by weight inhibited liquid formaldehyde solution and 126 g (mole) of 85% active formic acid were charged to a 1 liter four-necked stirrer, thermometer and condenser. The mixture was stirred for 0.5 hours at room temperature. The reaction mixture was heated externally and the mixture was heated to 60 ° q for 5 hours. The reaction temperature was gradually raised from 60 ° to the boiling point of the mixture. An exothermic reaction initiated π 38814

O

when the temperature rose above 60 C, was monitored by intermittent cooling. The boiling point of the mixture was reached after heating for three hours. The mixture was allowed to boil for 15 minutes, after which it was rapidly cooled to 55 ° C.

42 g of methanol were added to etherify the free methyl groups and the mixture was stirred for 2.5 hours, after which it was cooled to 25 ° C. The reaction product obtained was a water-soluble dicyanamide amide-formaldehyde condensate which was a clear water-soluble syrup containing 40% by weight of a solid.

This resin was evaluated according to the method of Example 3 to give the following results.

Concentration (ppm) Deposition (mg) zero 229 2 ppm 293 10 ppm 80

Comparative Example 2

Certain products potentially suitable as resin pesticides were evaluated according to the method of Example 3 with the following results.

Product Concentration Deposition (mg) zero - 299 polyacrylate 100 ppm 212 cationic starch 100 ppm 94 alum 100 ppm 41

Example 4

To a mixture of 68.81 g of 32.7% dimethylamine and 121.4 g of water was added 25.35 g of 36% hydrochloric acid dropwise over 30 minutes. Reaction mixture 12 8881 4

O

the temperature was not allowed to rise above 35 ° C; some cooling was needed. 83.25 g of epichlorohydrin were added so that the temperature of the reaction mixture remained at 40 ° C. After completion of the exothermic reaction, the mixture was kept at 40 ° C until clear (1 hour). The mixture was heated to 60 ° C, after which ethylene amine was added rapidly over 5 minutes. The reaction mixture was kept at 65 ° C for another hour. The reaction mixture was cooled to room temperature. To 97.42 grams of this solution were added 22.56 g of octadecylamine (2 moles) and 7.5 g of 2-methoxyethanol (to facilitate dissolution). This slurry was slowly heated to 70 ° C and maintained at this temperature for 30 minutes. Raising the temperature to 75 initiated a highly exothermic reaction which required cooling to maintain the temperature at 75 ° C. After completion of the exothermic reaction, the mixture was heated to 90 ° C for 2 hours. The total solids content of the product obtained as a creamy emulsion was 18%.

Example 5

The product of Example 4 was evaluated using the method described in Example 3, but a different synthetic resin was used. This time, the resin solution was made by adding a mixture of 2.0 g of tall oil and 20.0 g of glycerol ester of the resin to 10.5 grams of 5% sodium hydroxide to form an emulsion. This was diluted with 187.5 g of isopropanol and 110 g of acetone to give a clear resin solution. 15 ml of this solution was added to one liter of water having a temperature of 20 ° C and a hardness of 220 ppm expressed as calcium carbonate. The pH was adjusted to 3.0 using concentrated hydrochloric acid and the experiment was performed for three minutes.

13 8 8 814

Concentration (ppm) Deposition (mg) zero 250 2 72 3.5 23 7.5 not applicable

Comparative Example 3

Polydiallyldimethylammonium chloride di (po1y-DADMAC) is one of the quaternary resins proposed in EP 58621 as a pitch control agent. This resin was tested according to the method of Example 5.

Concentration (ppm) Deposition (mg) 2 193 5 45 10 27

Comparative Example 4

A preferred quaternary compound suitable for controlling resin deposits in U.S. Pat. No. 3,619,351 is methyltriethanolamine. This material was synthesized from triethanolamine and dimethyl sulfate to give quaternary ammonium methyltriethanolamine monomethyl sulfate. This material was evaluated according to the method of Example 3 with the following results.

Concentration (ppm) Deposition (mg) zero 130 10 ppm 165 100 ppm 102

Comparative Example 5

A resin was prepared from dimethylamine and epichlorohydrin following essentially the procedure of Example 1 of U.S. Patent No. 28,807. A 500 ml round-bottomed flask equipped with a condenser of 14,888,814, a mechanical stirrer and a pH electrode was used for the preparation. 92.5 grams (1.0 mol) of epichlorohydrin was charged to the flask. 112.5 grams of 40% liquid dimethylamine (45 grams of actual, 1.0 mol) was added with vigorous stirring for one hour, keeping the temperature below 50 C. The temperature was allowed to stand at 50 ° C for another two hours, after which the mixture was added. 70 g of water. The viscosity of this resin was determined to be 72 cps and the dry matter content was found to be 47%.

Example 6

The equipment used in Comparative Example 5 was used; 63.5 g of water, 9 g of ethylenediamine and 121.9 g of a liquid solution (36.9%) of dimethylamine were added to the reaction flask.

170 g of epichlorohydrin were added over three hours, keeping the temperature below 35 ° C by cooling. The temperature o was then raised to 80 ° C. 11.8 g of epichlorohydrin were added in six portions over three hours and the reaction mass was kept at 80 ° C for the next two hours after the last addition, after which the product was cooled to room temperature. The product was obtained as a pale yellow, slightly transparent liquid with a dry matter content of 65.8% and a viscosity of 190 cps.

Example 7

The equipment used in Comparative Example 5 was used. Water (34.2 g), dimethylamine (60.9 g of a 36.9% liquid solution) and ethylenediamine (1.5 g) were charged to the reaction flask. 51.0 g of epichlorohydrin were added with vigorous stirring over two hours, the temperature was raised to 80 ° C and 10.6 g of epichlorohydrin was added in 9 portions over 8 hours. The final product was a slightly transparent, pale yellow liquid. The dry matter content of the product was found to be 58.8% and the viscosity about 1000 cps.

is 88814

Example 8

The equipment used in Comparative Example 5 was used.

The resin was prepared as follows: 112.5 g of 40% dimethylamine and 10.2 g of dimethylaminopropylamine were added to the reaction solvent. The two amines were mixed together and 102 g of epichlorohydrin were added over 30 minutes with vigorous stirring and maintaining the temperature at 30 ° C. At -40 ° C. The temperature was then raised to 60 ° C and held for 5 hours. During this time, 300 ml of dei oni soi water was added in small portions. This resin had a viscosity of 20 cps and a dry matter content of 33%.

Example 9

The products of Comparative Examples 5, 6 and 8 were evaluated according to the method of Example 5 by adding 0.1 ppm polymer with the following results:

Product Deposition (mg) zero 272 Resin of Example 7 201 Resin of Example 6 Resin of Comparative Example 5 228 Resin of Example 8 186 Zero 260

Example 10

The resin of Example 6 was evaluated according to the method of Example 3. The following results were obtained:

Concentration (ppm) Deposition (mg) zero 133 2 ppm 121 5 ppm 29 10 ppm 6 16 «8814

Example 11

The utility of the polymers together with the anionic components dissolved in the pulp was investigated according to the following experiment:

The dried wood chips from the pine were decomposed for 30 minutes to produce a 2.5% pulp. The fibers were filtered and the filtrate was used to examine the capacity of the resin to interact with the dissolved anionic material. The amount of anionic material was determined by a flow voltage indicator. Polyethyleneimine (PEI) was used as a standard. The effectiveness of the resin in working with the anionic material was evaluated by adding varying amounts of resin to the filtrate, stirring for 15 minutes, and determining the residual content of non-combined anionic material by titration with a standard reagent. The result was as follows: PEI mg / l filtrate zero 7.1 4 ppm resin of Example 7 4.8 8 ppm resin of Example 7 1.9 4 ppm resin of Example 8 4.6 8 ppm resin of Example 8 1.4 8 ppm resin of Example 2 6.4 50 ppm of the resin of Example 2 2.3

Claims (18)

A resin control method for a liquid system used in the manufacture of pulp or paper, characterized in that it comprises a water-soluble, polyquaternary, branched polymer derived from (a) an epihalohydrin, diepoxide or epihalide of an epihalohydrin or diepoxide precursor, (b) is two, and (c) an amine having an epihalohydrin functionality greater than 2 and no carbonyl groups is added to the system or pulp or papermaking machinery, and that the process further meets one or more of the following characteristics: i) the polymer is added to the pulp or papermaking machinery , ii) the pulp is obtained from a binder-containing recovered paper, and iii) the polymer is obtained by first reacting components (a) and (b) with each other and then reacting the obtained intermediate and component (c). Process according to Claim 1, characterized in that component (a) is epichlorohydrin or epibromohydrin. Process according to Claim 1 or 2, characterized in that component (b) is a dialkylamine in which the alkyl groups individually contain 1 to 3 carbon atoms. Process according to Claim 3, characterized in that component (b) is dimethylamine. Process according to one of the preceding claims, characterized in that component (c) is a primary amine or a primary alkylene polyamine. ia # 8814 Process according to Claim 5, characterized in that component (c) is diethylaminobutylamine, dimethylaminopropylamine or ethylenediamine. Process according to one of the preceding claims, characterized in that the polymer is also derived from a tertiary amine or hydroxyalkylamine. Process according to Claim 7, characterized in that the polymer is also derived from trimethylamine or triethanolamine. Process according to one of the preceding claims, characterized in that the polymer is formed by reacting ethylenediamine with a precondensate of dimethylamine and epichlorohydrin and reacting the product with triethanolamine to form a water-soluble reaction product. Process according to one of Claims 1 to 8, characterized in that the polymer is formed by reacting a mixture of dimethylamine and ethylenediamine or dimethylaminopropylamine with epichlorohydrin to form a water-soluble reaction product. Process according to one of the preceding claims, characterized in that the equivalence ratio between component (c) and the sum of components (a) and (b) is 1: 0.22-2.5. Method according to one of the preceding claims, characterized in that the polymer is added to the liquid system together with the pulp contained in the pulp. Process according to one of the preceding claims, characterized in that the amount of polymer to be added is from 1000 to 50,000 grams per ton of fiber. 19 88814 Method according to one of Claims 1 to 11, characterized in that the polymer is sprayed onto at least one part of the pulp or papermaking machine. Method according to one of the preceding claims, characterized in that a biocide is also added to the liquid system. A method according to claim 14, characterized in that the polymer is sprayed onto the papermaking fabrics. Process according to Claim 14, characterized in that the polymer is applied as an aqueous solution in which the polymer concentration is less than 10% by weight. 17 8 8 814 Method according to one of the preceding claims, characterized in that the paper is made from recovered paper containing a binder.