FI106056B - Procedure for checking resin deposition from pulp in papermaking - Google Patents

Abstract

An improved process for controlling natural pitch deposition in pulp and papermaking aqueous systems involves the use of ampholytic polymers containing diallyl dimethyl ammonium quaternary salts and also containing (meth) acrylic acid salts and optionally containing (alkyl) acrylic acid esters or hydroxy esters. These ampholytic polymers give improved results in terms of control of natural pitch in the manufacture of pulp and paper.

Description

, 106056

This invention relates to an improved method of controlling the deposition of natural resin by treating the various wood pulps used in the manufacture of paper products.

Deposits of natural resin are detrimental to the efficient use of paper mills. The resin is deposited on the process equipment used in papermaking systems, causing operating problems associated with the accumulation of pitch deposits in the consistency control devices and other instrumentation sensors used to monitor the papermaking process with different types of paper pulp 15 and raw materials.

In addition, resin deposits may form on screens and reduce the amount of material passing through the equipment, as well as malfunctions in the papermaking process. The accumulation of natural resin can occur not only on the metal surfaces of the system but also on plastic and synthetic surfaces such as wires, felts, ejectors, UHLE boxes and headbox components. These resin deposits can also break, causing blemishes and defects in the final paper product, thereby degrading paper quality.

Surfactants, anionic polymers and copolymers of anionic monomers and hydrophobic monomers have been widely used to prevent pitch deposition. For example, in "Pulp and Paper," kir-30, edited by James B. Casey, vol. II, second edition, pp. 1096-7, describes polymers of this type for this purpose.

In addition, bentonite, talc, diatomaceous earth, silica, starch, animal glue, gelatin and aluminum sulphate have also been used to reduce pitch deposits.

106056 2 U.S. Patent 3,081,219 to Drennen et al. Describes the use of polymeric N-vinyl lactam for pitch control in the manufacture of paper from sulfite paper pulps.

In addition, the following patents disclose the use of various chemicals, both polymeric and non-polymeric, in the control of pitch: U.S. Patent 3,154,466 to Nothum; 3,582,461 to Lipowski et al .; 3,619,351, Kolosh; 3,748,220, Gard; 3,992,249, Farley; 4,184,912, Payton; 4,190,491 to Drennen et al .; 4,253,912, 10 to Becker et al .; 4,871,424 to Dreisbach et al .; 4,765,867,

Dreisbach et al .; and 4744865, Dreisback et al .; CA patents: 1,194,254, Molnar; and 1,150,914, Molnar; and U.S. Patent 4,313,790 to Peiton et al.

All of the abovementioned patents disclose certain methods and formulations, including cationic polymers and, in particular, cationic polymers as defined in CA Patent Specification 1,194,254, formed by the polymerization of diallyl dimethyl. styled ammonium chloride, which polymers are useful for pitch control.

In addition, an article published by the Institute of Paper Science and Technology in Atlanta, Georgia, edited by Weigel, et al., Entitled "Resin Deposits and Their Control in Paper-25 Making", translated from Papier 40 (10A) ): V52-62 (October 1986), also described resin deposits and their control in various paper mills.

One article, "Unusual Applications of Dual Polymer Systems" by Dykstra et al., Published in Semi-30, 1987, TAPPI Advanced Topics in Wet End: Chemistry Seminar, describes the use of anionic polymers in combination with charged condensation polymers having cationic charge.

Another article, titled "Pitch and Stickies 35 Control in Pulp and Paper Mills," by Pamela J. Allison, published July 10, 10566 in Paper Southern Africa, vol. 8, No. 3, 1988, discusses resin and noxious resin deposits and techniques for controlling them. Another publication, Dykstra et al., Entitled "A New Method for Measuring-5 Ring Depositable Pitches and Stickies and Evaluating Control Agents," published in Conference Publication 1988 TAPPI Papermakers Conference Proceedings, p. 327, also discusses the control of pitch and nox. The publication also describes a bipolar treatment.

10 Finally in Tappi Journal, June 1988, p.

195, an article by Hassler entitled "Pitch Deposition in Papermaking and the Function of Pitch Control Agents," describes various pitch control agents and techniques to assist in pitch stratification and control.

None of the references, including Special CA Patent Specification No. 1,194,254, Molnar, which describes a homopolymer of DADMAC, i.e., diallyl dimethyl ammonium chloride. use of polymer, there is no mention of the use of ampholytic polymers containing diallyl dimethylammonium halide monomers.

Accordingly, it is an object of this invention to provide an improved method for controlling the accumulation of natural pitch in the production of paper pulp and paper.

The present invention provides a process for controlling natural pitch deposition on paper machine surfaces, which comprises adding to the resin contaminated fiber material a pitch control agent prior to forming, comprising 30 effective resin controlling agent 10, which is 4

- - R - R

--ch2 --- --- CH 2 CH 2 CH 2 C --- C--

c kW C = 0 0 = C

3 Nil

x (-) / \ I I

R R O O

?????????????????? LL MJ? BLJ d (R ·) (V) e 10 wherein R is in each case H, CH 3 and C 2 H 5; R 'is a polyhydric hydrocarbon bridging group having from 1 to 24 carbon atoms and selected from straight chain and branched alkyl groups, cyclic groups, aromatic groups, alk-15-yl and aralkyl groups and mixtures thereof; M is, at each occurrence, H, alkali metals, alkaline earth metals of equivalent amount, ammonium, protonated amine and quaternary ammonium cations, and mixtures thereof; · X is an anion present in electron-neutral amounts relative to positively charged nitrogen in the polymer backbone; Y is -H, -OH, and mixtures thereof; and the sum a + b + d is sufficient to provide a weight average molecular weight in the range of about 10,000 to about 1,000,000; E is 0 to 6; and the following ratios are present: a: b is at least 3: 1, a: (b + d) is at least 75:25, d: (a + b) is in the range from 0 to 1: 9; and d, but not a or b, may be 0.

30 Polymer structure

The polymer structure is as described above. In this structure, each monomer unit is distributed substantially randomly along the polymer chain, and the polymer is ampholytic in nature, i.e., it can have both positive and negative charges.

106056 5

In addition, the polymer may optionally contain from 0 to about 10 mol% of monomer, which is oleophilic in nature. This oleophilic monomer is preferably an ester or hydroxy-5-ester of acrylic acid, methacrylic acid or ethacrylic acid, or a mixture thereof.

The cationic nature of the above-described polymers is achieved by the inclusion of about 75 to about 95 mol% of diallyl dimethylammonium salts. These salts may be chlorides, bromides, iodides, sulfates, nitrates, phosphates and the like. Preferably, these quaternary divinyl salts are in the form of diallyl dimethylammonium chloride (known as DADMAC). The diallyl dimethylammonium chloride (DADMAC) monomer is present in the polymer in an amount of from about 75 to about 95 mol%, preferably from about 80 to about 90 mol%, and most preferably from about 85 to about 90 mol%.

This results in a huge positive charge on the backbone polymer.

However, it has been shown that improvements in the use of these materials as pitch control agents result in the incorporation of from 2 to about 25 mol% of anionic monomer units in the backbone of the above-described polymers.

A preferred anionic monomer is selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, and their common salts, or mixtures thereof. The salts are preferably in the form of alkali metal salts, equivalent amounts of alkaline earth metal salts, or ammonium cations, quaternary ammonium cations, or protonated amine cations. Most preferably, the anionic monomer is acrylic acid or methacrylic acid, or mixtures thereof, used either as the free acid or as the sodium, potassium, and / or ammonium salt. Of course, all mixtures of salts and their incorporation into the above monomer structures are included in the concept of the use of these anionic monomer units. These anionic monomers may be represented by the term (meth) ak-35 acylic acid, but this term is used herein to represent any mass of vinylic acid or vinylic acid salt having the structure:

R O

5 CH 2 = C - C - OM

wherein R is H, CH 3, C 2 H 5 and mixtures thereof; and M is as defined above.

As above, the polymer may be improved by the inclusion of optionally certain oleophilic monomers, such as (meth) acrylic acid esters or (meth) acrylic acid hydroxy esters. These compounds give the polymer a somewhat oleophilic character and can help to collect and disperse the resin particles and to attach these resin particles to the cellulosic fibers so that they do not undesirably accumulate on paper machine surfaces or cause other papermaking problems. These vinylic acid esters and vinylic acid hydroxy esters are the main, ·. in particular, materials selected from acrylic acid esters, methacrylic acid esters or ethacrylic acid esters. The term acrylic acid ester, methacrylic acid ester, or ethacrylic acid ester also refers to hydroxy esters containing 1 or more hydroxyl groups attached to the ester acid in the alkyl unit.

Preferred is a polymer having a molecular weight in the range of about 10,000 to about 1,000,000, and most preferably about 50,000 to about 500,000. These molecular weights are weight average molecular weights. The most preferred polymer contains about 80 to about 90 mol% of diallyl dimethylammonium chloride, about 5 to about 20 mol% of acrylic acid or: methacrylic acid or mixtures thereof (or salts thereof) and about 0 to about 10 mol% of acrylic acid esters from hydroxyalkyl acrylate and alkyl acrylates or mixtures thereof, wherein the alkyl group 106056 7 of the ester functionality has from about 1 to about 24 carbon atoms, preferably from about 2 to about 14 carbon atoms.

The ampholytic polymers of the invention need not necessarily contain (meth) acrylate esters or hydroxyalkyl (meth) acrylate esters, but may be formed only from diallyl dimethylammonium chloride (or other salt) and either acrylic acid, methacrylic acid, or their methacrylic acid. When using copolymers, DADMAC is preferably present in an amount of from about 80 to about 95 mol%, and anionic (meth) acrylic acid units are present in an amount of from about 5 to about 20 mol%. Most preferably, these copolymers contain from about 80 to about 90 mole percent DADMAC and from about 10 to about 20 mole percent (meth) acrylic acid or its salts.

15 Dosing

Typically, the dosages of the products containing the resin control agents described above will normally be in the range of about 25 g to about 10 kg of formulated product. t / l 000 kg paper product based on dry fiber. The pitch control agents are provided as liquid dispersions or solutions of the normally described polymers in water, which normally contain from about 1% to about 40% by weight of the active polymer. The polymer may also be obtained as a water-in-oil-latex emulsion containing a dispersed aqueous phase in which the polymer described above is dissolved. This emulsion normally also contains a controlled HLB surfactant system so that when the water-in-oil emulsion is added to the papermaking system, phase inversion occurs and the polymer dissolves and disperses rapidly in aqueous paper. Preparation of the medium. When the product is supplied as a water-in-oil emulsion, the polymer content of the emulsion product may range from about 5% to about 55% by weight of the product. On the basis of the active polymer, the polymer dosage of the inventive polymers and the polymers described above will normally be in the range 1060568 to about 25 g to about 1.0 kg / 1000 kg active polymer at base / 1000 kg dry fiber. The following examples are provided to further illustrate and illustrate the invention.

5 Examples

Laboratory tests for the products described above were performed by the following method:

Example 1

About 7,000 ml of hardwood kraft pulp stock solution was prepared. This hardwood kraft stock solution contained 2.27% by weight of fiber. This pulp material was diluted with water until it contained about 1.5% by weight of leaf-kraft pulp fiber. The pH of this stock solution was adjusted to about 10.6 with sodium hydroxide solution. About 15 100 ml dispersion of 1% laboratory resin mixture was added to 700 ml 1.5% hardwood kraft pulp. The pH dropped to about 7.4 - 7.5. To this resinous hardwood kraft pulp slurry was added 5 ml of a 0.5 molar solution of calcium chloride dihydrate. This mixture was stirred slowly and the pH was checked. The pH had dropped to about 6.5. The pH value of this test is preferably in the range of 5.5 and 7.0 during the course of the pitch control of the pitch.

The hardwood kraft blend containing 25 synthetic resin dispersions and calcium chloride is then poured into a laboratory mixer. To this slurry is added a pre-weighed polytetrafluoroethylene (PTFE) pad which acts as a surface on which the resin accumulates. This PTFE tag is added to the mixer in the pulp kraft contaminated with pih-30. The used mixture; the probe had 14 buttons that control the speed of the mixer pad. After adding the pre-weighed PTFE pad, push button 4 and mix for 3 minutes. Other mixer-35 speeds may also be used. A resin layer is obtained on the PTFE pad, and once the 106056 9 pad is removed, rinsed with distilled water from a wash bottle and air dried, the tag is weighed. The drying time may be in the range of about 4 to about 24 hours. The amount of resin deposited is calculated as the difference from the original weight of the tag.

Using this technique, the following results were obtained for each test sample.

Table I

10 Resin deposition test

Resin Deposition with Polymer # 1 and Treatment with Polymer # 3 Dose (g / 100 kg) Resin Resin-Active-Deposition from Nuclear Weight 15 of Tea _ (mg)% Reduction Control 1090 290 polymer # 1 50 250 10 97 Polymer # 3 50 250 9 97 Control-2 0 0 288 • 20 Polymer # 1. 100 500 5 98 Polymer # 3 100 500 2 99 Control-3 0 0 309 Polymer # 1 250 1250 3 99 Polymer # 3 250 1250 2 99 25 Mean Control (Untreated) Pitch Weight = 296 mg 1 standard deviation = 12 mg Pitch Reduction 30 -% = wt (control) - wt (treated) x 100 wt (control) polymer # 1 polyDADMAC; mp. 150,000, 20% polymer solids, charge 6.19 meq / g polymer polymer # 3 polyamolyte coagulant; 20% polymer solids, DADMAC: acrylate: hydroxypropyl acrylate terpolymer 40 87: 10: 3 molar ratio charge 4.92 meq / g polymer (pH> 8.0) charge 5.57 meq / g polymer (pH <4) , 5) 10 106056

Example II

In addition, various tests were carried out with trial and error on the pulp of a paper machine obtained from a paper mill in active production.

The pH of the paper machine bath pulp was measured to 7.95 and samples of this pulp were laboratory treated with a homopolymer of diallyl dimethylammonium chloride as described by Molnar and simultaneously treated with the polymers of the invention. The results are shown in Table II.

10

Table II

Decrease in colloidal pitch and anionic "waste" concentration in the pulp of a Southeastern US paper mill 15 Product Treatment Permeability% Filtration Dispensing (PTU) Turbidity (kg / 1000 ka) Reduction% * control 0 44 polymer # 1 1.55 44 0 * * - - · "^ 20 Polymer # 1 3.1 54 23 Polymer # 1 4.65 69 57 Polymer # 2 1.55 44 0 Polymer # 2 3.1 48 9 Polymer # 2 4.65 62 41 25 Polymer # 3 1.7 46 4 Polymer # 3 3.4 69 57 Polymer # 3 5.1 84 91 Cloud Compaction Cloud% = 30 Turbidity (Treated) - Turbidity (Control) x 100 Turbidity (Control) 35 Polymer # 1 = PolyDADMAC Homopolymer Polymer # 2 = PolyDADMAC Solution Polymer (Different Manufacturer)

Polymer # 3 = 87 mol% DADMAC of the ampholytic polymer of the invention

10 mol% acrylic acid (Na salt) 40 3 mol% hydroxypropyl acrylate u 106056

Success is measured in Table II by the percentage reduction in filtrate turbidity, which is a measure of the amount of pitch that is suspended and adhered to the fiber without affecting the filtrate turbidity.

In addition to Polymer # 3 which is a polyampholyte containing DADMAC / acrylic acid, salts and hydroxypropyl acrylate terpolymer, as described above, the following information describing other copolymers and terpolymers within the scope of the claims of the invention and their experimental polymers are also provided. use to control pitch deposition.

Examples III. (A-L)

The following test polymers were processed in the laboratory using the methods described in Example I except that modified synthetic laboratory resin was used.

12 106056

Table III

Other Ampholytic Polymers Polymer Monomer Type Solids Viscosity & Mole Ratio *% Substance Theta (dl / g) 5 Polymer 1 DADMAC (100%) 20 0.63 Poly Ampolyte (A) DADMAC: AA: HPA 20 1.08 (87:10 : 3) poly-DADMAC: AA (90:10) 20 0.92 10 ampholytic (B) poly-DADMAC: AA (95: 5) 22.6 0.93 ampholytic (C) poly-DADMAC: AA (85: 15) 23.3 0.80 ampholytic (D) 15 poly- DADMAC: AA (80:20) 23 0.72 ampholytic (E) poly- DADMAC: MAA (98: 2) 21 0.74 ampholytic (F) poly - DADMAC: MAA (95: 5) 22.8 0.70 20 ampholytic (G) poly- DADMAC: MAA (85:15) 22.5 0.37 ampholytic (H) poly- DADMAC: 2-EHA (97: 3) 21.9 0.86 Ampole (J) 25 Poly-DADMAC: 2-EHA (95: 5) 22.5 0.74 Ampole (K)

DADMAC

copolymer (L) DADMAC: α-MS (97: 3) 13.9 0.21 * DADMAC = diallyl dimethylammonium chloride 30 AA = acrylic acid. MAA = methacrylic acid 2-EHA = 2-ethylhexyl acrylate α-MS = α-methylstyrene HPA = hydroxypropyl acrylate 106056 13

The results of polymer testing are shown in Table IV below:

Table IV Resin Deposition 5 PolyDADMAC Compared to Polyamyphytes A to K and

DADMAC copolymer L

treatment dose (q / 100 kg) resin coagulant active precipitation from rust from tea _ (mg) weight loss * control-1090 78 p-DADMAC 5.0 25 64 12 p -amfol. A 5.0 25 71 3 p-Amphol. B 5,0 25 63 14 15 p-amphol. C 5.0 20 68 7 p-Amphol. D 5.0 20 66 10 p-Amphol. E 5,0 20 70 4 Control-2 0 0 73 p-DADMAC 25 125 42 42 20 p-Amphol. A 25 125 47 36 p-Amphol. B 25 125 19 74 p-Amphol. C 25 110 31 58 p-amphol. D 25 110 24 67 p-amphol. E 25 110 39 47 25 Control-3 0 0 57 p-DADMAC 50 250 18 75 p-Amphol. A 50 250 20 73 p-amphol. B 50 250 11 85 p-Amphol. C 50 220 12 84 30 p-amphol. D 50 215 20 73 - p-amphol. E 50 220 17 77 control-4 0 0 85 control-0 0 72 p-DADMAC 5.0 25 73 9 35 p-amphol. F 5.0 25 72 10 106056 14

Table IV (continued)

Resin deposition

PolyDADMAC compared to polyamolyte A-K and DADMAC copolymer L

5 treatment dose (g / 100 kg) resin coagulant active precipitation from rust from tea _ (ma) weight loss -% * p-amphol. G 5.0 20 77 38 10 p-Amphol. H 5.0 20 80 0 p-Amphol. J 5.0 25 70 13 p-Amphol. K 5.0 20 73 9 DAD / Cop. L 5.0 35 68 15 Control-2 0 0 89 15 p-DADMAC 25 125 60 25 p-Amphol. F 25 120 24 70 p-Amphol. G 25 110 35 56 p-amphol. H 25 110 53 34 p-amphol. J 25 115 34 58 20 p-amphol. K 25 110 35 56 DAD / Cop. L 25 180 52 35 Control-3 0 0 83 p-DADMAC 50 250 35 56 p-Amphol. F 50 240 18 78 25 p-amphol. G 50 220 13 84 p-Amphol. H 50 220 27 66 p-Amphol. J 50 230 18 78 p-amphol. K 50 220 20 75 DAD / Cop. L 50 360 50 38 30 control-4 0 0 84 control-5 0 0 74 «

Mean control (untreated) resin weight = 80 mg 1 standard deviation = 7 mg 35 *% resin reduction = weight (control) - weight (treated) x 100 weight (control) 106056

The resin dispersion used in the lime for the above tests, using the methods set forth in Example I, is a synthetic laboratory resin consisting of a mixture of fatty and resin acids and esters, sterols, steroids and fatty alcohols which represents the correct softwood and / or lehtipuupihkaa. This synthetic resin is used in the form of a 1% dispersion as described in Example I and the concentration ranges of its constituents are described in Table V.

10

Table V

Synthetic laboratory resin% Chemical composition 5 - 50 Abietic acid (resin acid) 15 10-25 oleic acid 5 - 10 Palmitic acid 10 - 35 Corn oil 5 - 15 Methyl stearate 2.5 - 7.5 β-sitosterol 20 2.5-7.5 Cholesteryl caproate 2.5-7 Oleyl Alcohol This synthetic lab resin is dispersed in isopropanol to form a 1% dispersion used as in Example I.

4

Claims (5)

A method for controlling the precipitation of natural chain on paper machine surfaces, in which process chain regulating agent is added to the chain contaminated fibrous material prior to sheet forming, characterized in that an effective amount of the chain regulating agent is used to control the precipitation of the chain and the chain regulating agent is a copolymer having the following structure: 1 Γ ϊ 1 Γ f —ch2 --- ch2 --- ch2 — c --- ch2 — c-- \ IIRROOL JaL M JbL | Jd op OOe where R is H, CH3 or C2H5; R 'is a multivalent hydrocarbon bridge ligand containing * 1-24 carbon atoms and which is a straight chain or branched alkyl group, cyclic group, aromatic group, alkaryl and aralkyl group or a mixture thereof; M is H, alkali metal, alkaline earth metal in equivalent amount, ammonium, protonated amine and quaternary ammonium cation - or a mixture thereof; X is an anion present in electron neutral amounts relative to the positively charged nitrogen in the polymer backbone; Y is H, OH or a mixture thereof; and the sum a + b + d is sufficient to achieve the mass average molecular weight, which is between about 10,000 - about 1,000,000; e is 0 - 6; and where the following ratios occur: 5 a: b is at least 3: 1, a: (b + d) is at least 75:25, d: (a + b) is at least 0 - 1: 9; and d, but not a or b, can be 0. 2. A process according to claim 1, characterized in that the chain regulating agent is terpolymer, whose molecular weight mass value is between about 50,000 - about 500,000, and R is CH3 when bonded to the nitrogen in the polymer structure, and H, CH3. or a mixture thereof when bonded to the carbon of the polymer structure; R 'is a straight chain or branched alkyl group having 1-16 atoms; and e is 0-4; and the following ratios suggest: a: b is at least 4: 1, 20 a: (b + d) is at least 80:20 and d: (a + b) is in the range 0 - 1: 9, and the effective copolymer amount controlling the precipitation of the chain is in the range of about 0.05 - about 1000 g of active copolymer per ton of dry fiber. ? *. .25 Process according to claim 1 or 2, characterized in that the chain regulating agent is added to the pulp before sheet forming with an amount of about 25 g of active polymer (of the dry substance) per tonne of paper fiber (of dry cellulose fiber). 30 4. A process according to claim 1, characterized in that the polymer has the following structure: - CH, -ί-1-CH, --- CH2-C -: - CH2-C-- II coo - c χ (-) / N \ I I. RR 0 0 L JaL M JbL I Jd (R ') (Y) e where R is H or CH3; R 'is a straight chain or branched alkyl group having from 1 to about 14 carbon atoms; X is Cl, M is H, Na, K, Li, NH 4 or mixtures thereof; Y is H and OH, and a mixture thereof; e is 0 - 2; and the sum a + b + d is sufficient to obtain approx. 50000-500000 molecular weight mass average; d, but neither a nor b, can be 0; and the ratio a: b is at least 4: 1; and the ratio d: (a + b) never exceeds 1: 9. 5. A process according to claim 4, characterized in that polymer is added to the pulp with an amount of about 25 - 750 g of active polymer per ton of paper calculated on dry fiber. ».