Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/02—Agents for preventing deposition on the paper mill equipment, e.g. pitch or slime control
  • D21H21/04—Slime-control agents

Definitions

• the present invention relates to an improved method of pro­viding a clean sheet forming equipment and the like for paper pro­duction and, more particularly, to chemical treatment of paper making equipment to control productivity disturbing, microbiologi­cally originated deposits thereupon.
• the invention also relates to the paper produced by said improved method.
• the manufacture of paper typically involves the processing of a carefully prepared aqueous fiber suspension to produce a highly uniform dry paper sheet.
• Three steps included in the typi­cal process are sheet forming, where the suspension is directed over a porous mesh or "wire” upon which fibers are deposited while liquid filters through the wire; sheet pressing, where the formed sheet is passed through presses covered with porous "felt” to extract retained water from the sheet, to improve the sheet's uni­formity, and to impart surface quality to the sheet; and paper drying, where residual water is evaporated from the sheet.
• the sheet may then be further processed into the finished paper pro­duct.
• the quality of the aqueous fiber suspension used to produce the sheet is dependent upon many factors, including the wood and water used as raw materials, the composition of any recycled mate­rial added to the process, and the additives used during prepara­tion of the suspension.
• a variety of dissolved or suspended materials can be introduced into the manufacturing process, inclu­ding both inorganic materials such as salts and clays, and mate­rials which are organic in nature such as resins or "pitch" from the wood, as well as inks, latex, and adhesives from recycled pa­per products.
• a build up of deposits contaning inorganic and/or organic materials on felts and other sheet forming equipment dur­ing the manufacturing process is recognized as a troublesome ob­stacle to efficient paper making.
• slimy gela­tinous material produced by certain bacteria that naturally occur in the paper making system.
• This material is hereafter referred to as "slime"
• the problems with slime deposit build-ups on paper machine parts often become severe and will, if not inhibited, lead to significant productivity disturbances in the paper making pro­cess.
• a typical problem caused by slime deposits occurs when big lumps of built-up slime fall down from the position where they were formed onto the paper sheet, thus causing a sheet defect and/or break.
• biocides are methylene-bis-thiocyanate, 5-chloro-2-methyl-4-iso­thiazolin-3-one and 2-methyl-4-isothiazolin-3-one.
• one object of the invention is to provide an im­proved paper making method where the deposition of organic matter of the above-mentioned type is controlled, i.e. prevented or inhi­bited completely or at least to a very great extent if not already having been formed, or reduced or dispersed completely or to a great extent if already having been formed.
• the invention is espe­cially interesting in connection with the control of slime caused by slime forming microorganisms.
• Another object of the invention is to provide a new method, by which the use of toxic biocides is eliminated or greatly reduc­ed, i.e. to provide a paper mill deposit control method which is environmentally acceptable.
• Still another object of the invention is to provide a new method, by which the incorporation of chemicals into the paper pulp is avoided or reduced.
• a further object of the invention is the provision of a method, by which considerably reduced concentrations of chemicals are utilized to control the deposit problems referred to above.
• a still further object of the invention is the provision of a method, by which the productivity and product quality in paper making is increased.
• a still further object of the invention is the provision of a high quality paper whenever manufactured by the method claimed.
• the above-mentioned objects and other objects are accomplished by the provision of a method of controlling productivity disturbing microbiological deposits on paper making equipment, said method being characterized by apply­ing to any locus or surface of said paper making equipment which locus or surface is sensitive to build-ups of such microbiological deposits, a deposition-controlling amount of a deposition-con­trolling substance selected from the group consisting of cationic polymers and cationic surfactants, which includes mixtures thereof.
• control should be given a broad sense in the meaning of the invention. That is, according to the invention it has unexpectedly been found that the application of the cationic polymer or surfactant or mixture thereof can be utilized to prevent or inhibit the formation of deposits as well as to dissolve or disperse deposits which have already been formed.
• any locus or surface of the paper making equipment which is sensitive to build-ups of such deposits or similar, it should be noted that the general meaning thereof is that the cationic polymer or sur­factant is not incorporated into the pulp or paper but is applied onto any strategical part or position of the paper making equip­ment.
• the cationic polymer or surfactant is not incorporated into the pulp or paper but is applied onto any strategical part or position of the paper making equip­ment.
• the polymer or surfactant can be applied onto more than one such locus or surface if necessary or advisable.
• the invention is generally applicable to any water soluble cationic polymer or surfactant of the type referred to, which pri­marily means that an aqueous solution of said polymer or surfac­tant is utilized.
• This in turn means that an especially preferable method of applying the cationic polymer or surfactant onto said locus or surface is by means of a spraying operation, as this is generally a simple operation and as such an operation has been shown to be very effective in connection with the invention. That is, it has unexpectedly been shown that very low concentrations of the polymer can be utilized in this way for outstanding results.
• the method claimed is generally applicable to the control of any deposits caused by microorganisms, but it has been found to be especially interesting to control deposits caused by bacteria, e.g. slime caused by slime-forming bacteria.
• the major characteristic feature of the invention is the application of the cationic polymer or surfactant directly onto the locus or surface to be treated, said polymer or surfactant being utilized in unexpectedly low concentrations, the precise nature of the polymer or surfactant to be used is not the main characteristic of the invention, provided it is of the cationic type.
• a considerable variety of different polymers and sur­factants may be used within the scope of the invention, i.e. also based on previously known microbiocidal activities.
• a number of especially preferable polymers and surfactants will be disclosed below.
• a water soluble polymer or surfactant is used.
• a cationic polymer which has a molecular weight within the range of 1,000 - 5,000 000, e.g. between about 10,000 and about 300,000.
• a preferable embodiment within said ranges is from about 20,000 to 300,000, especially from about 20,000 to 50,000.
• Another preferable range is from about 10,000 to 50,000.
• a preferable range of the mo­lecular weight thereof is between about 200 and about 600.
• an aqueous solution of the polymer or surfactant is used which is substantially free from anionic macromolecules.
• the charge density of the compounds embodied by the inven­tion should be in a range of between about 0.5 milliequiva­lents/gram and 20 milliequivalents/gram. A preferable embodiment within said range is about 1-10 milliequivalents/gram, especially about 2-8 milliequivalents/gram.
• One preferred group of cationic polymers according to the invention comprises dicyandiamide-formaldehyde condensation poly­mers. Polymers of this type are disclosed in many patients. US 2,774,74, US 2,829,126, GB 1,193,29, DE 917,392, FR 1,484,381, DE 2,017,114, JP 75,111,864, JP 73,16,067, DE OS 2,515,175, CH Appli­cation 9,527/72, DE OS 2,451,698, DE 1,128,276, DE OS 2,403,443, FR 1,414,407 and DE 2,321,627 represent some examples thereof.
• Another preferable group of cationic polymers to be used in accordance with the invention is those polymers which are formed by reaction between epihalohydrins and various amines.
• the most preferred epihalohydrin in this respect is epichlorohydrin, and as examples of suitable amines reference can be made to dimethylami­ne, diethylamine, methylethylamine, ethylene diamine, triethanol amine and a polyalkylene polyamine.
• suitable amines reference can be made to dimethylami­ne, diethylamine, methylethylamine, ethylene diamine, triethanol amine and a polyalkylene polyamine.
• Examples thereof include those polymers which are obtained by reaction between a polyalkylene polyamine and epichlorohydrin, as well as those polymers which are obtained by reaction between epichlorohydrin, dimethylamine and either ethylene diamine or a polyalkylene polyamine.
• a typical amine which can be utilized is N,N,N′,N′-tetra-methylethylene dia­mine as well as ethylene diamine used together with dimethylamine and triethanolamine.
• Polymers of this type include those polymers which have the following general formula: where A is a number within the range of 0-500.
• Preferred cationic polymers of this invention also include those made by reacting dimethylamine, diethylamine or methylethyl­amine, preferably either dimethylamine or diethylamine, with an epihalohydrin, preferably epichlorohydrin.
• Polymers of this type are disclosed in U.S. Patent No 3 738 945 and Canadian Patent No 1 096 070, the disclosures of which are both hereby incorporated by reference.
• Such polymers are commercially available as Agefloc A-50, Agefloc A-50HV and Agefloc B-50 from CPS Chemical Company, Inc., of New Jersey, USA.
• Another preferable group of cationic polymers for use in accordance with the invention comprises polymers derived from ethylenically unsaturated monomers containing a quaternary ammonium group.
• Such polymers may comprise homo- and copolymers of vinyl compounds, such as vinyl pyridine and vinyl imidazole, which may be quaternized with, say, a C1-C18-alkyl halide, a benzyl halide, especially a chloride, or dimethyl or diethyl sulphate, or vinyl benzyl chloride, which may be quaternized with for instance a tertiary amine of formula NR1R2R3, wherein R1, R2 and R3 are each and independently lower alkyl, preferable with 1-4 carbon atoms, with the proviso that one of said groups R1, R2 and R3 may be C1-C18-alkyl; allyl compounds such as diallyldimethyl ammonium chloride; or acrylic derivatives such as dial
• lower alkyl means an alkyl group containing 1-6 carbon atoms, unless otherwise stated.
• the monomers can be copolymerized for instance with a (meth)acrylic derivative such as an acrylamide, an acrylate- or methacrylate-C1-C18-alkyl ester or acrylonitrile, or an alkyl vinyl ether, vinyl pyrroli­done, or vinyl acetate.
• a (meth)acrylic derivative such as an acrylamide, an acrylate- or methacrylate-C1-C18-alkyl ester or acrylonitrile, or an alkyl vinyl ether, vinyl pyrroli­done, or vinyl acetate.
• Typical such polymers contain 10 to 100 mole percent of recurring units of the formula: and 0-90 mole percent of recurring units of the formula: wherein R1 represents hydrogen or lower alkyl, preferably alkyl with 1-4 carbon atoms, R2 represents a long chain alkyl group, typically of from 8 to 18 carbon atoms, R3, R4 and R5 each and independently represents hydrogen or lower alkyl, while X repre­sents an anion, typically a halide ion, a methosulphate ion, an ethosulphate ion, or 1/n of an n-valent anion.
• quarternary ammonium polymers derived from an un­saturated monomer include homo and copolymers of diallyldimethyl ammoniumchloride which contain recurring or repeating units of the formula: where Z represents monomeric units, like for instance a (meth)acrylic derivatives such as an acrylamide, an acrylate- or methacrylate -C 1-C18 -alkylester or acrylonitrile, or an alkyl vinyl ether, vinylpyrrolidone or vinyl acetate, m is within the range of 5-100% and n is within the range of 0-95%.
• Z represents monomeric units, like for instance a (meth)acrylic derivatives such as an acrylamide, an acrylate- or methacrylate -C 1-C18 -alkylester or acrylonitrile, or an alkyl vinyl ether, vinylpyrrolidone or vinyl acetate
• m is within the range of 5-100%
• n is within the range of 0-95%.
• this polymer should be regarded as “substantially linear” since although it contains cyclic groupings, these groupings are connected along a linear chain and there is no cross-linking.
• polystyrene resin Another class of polymer which can be used and which is de­rived from ethylenically unsaturated monomers include polybuta­dienes which have been reacted with a lower alkyl amine and some of the resulting dialkyl amino groups are quaternized. In general, therefore, the polymer will possess recurring units of the formula: in the molar proportions a:b:c:d, respectively, where R represents a lower alkyl radical, typically a methyl or ethyl radical. It should be understood that the lower alkyl radicals need not all be the same. Typical quaternizing agents include methyl chloride, dimethyl sulphate, and diethyl sulphate.
• Varying ratios of a:b:c:d may be used with the amine amounts (b+c) being generally from 10 to 90 % with (a+d) being from 90 to 10%.
• These polymers can be obtained by reacting polybutadiene with carbon monoxide and hydro­gen in the presence of an appropriate lower alkyl amine.
• cationic polymers which are capable of interacting with anionic macromolecules and/or slimy material in paper making pulp may also be used within the scope of this invention.
• These may include cationic tannin derivatives, such as those obtained by a Mannich-type reaction of tannin (a condensed polyphenolic body) with formaldehyde and an amine, formed as a salt, e.g. acetate, formate, hydrochloride, or quaternized, as well as polyamine poly­ mers which have been cross-linked, such as polyamideamine/poly­ethylene polyamine copolymers cross-linked with, say, epichloro­hydrin.
• Yet another suitable type of polymer is that formed by reacting a polyamido amine with epihalohydrine.
• Such crosslinked polyamidoamines are described in US patents 3,250,664, 3,893,885, 3,642,572 and 4,250,299, which are hereby incorporated by reference.
• the cationic surfactant is of the general formula wherein each R is independently selected from the group consisting of hydrogen, alkyl groups having between about 1 and 22 carbon atoms, aryl groups, and aralkyl groups, at least one of said R groups being an alkyl group having at least about 8 carbon atoms and preferably an n-alkyl group having between about 12 and 16 carbon atoms; and wherein X ⁇ is an anion, preferably a halide ion, e.g. chloride, or 1/n of an n-valent anion. Mixtures of these com­pounds can also be used as the surfactant of this invention.
• R groups of the surfactant are selectivelyed from the group consisting of methyl and ethyl, most preferably methyl.
• one R group is selected from the aralkyl groups Ph-CH2- and Ph-CH2-CH2-, where Ph is phenyl.
• the most pre­ferable aralkyl group is benzyl.
• particularly useful surfactants include alkyl dimethyl benzyl ammonium chlorides having alkyl groups of between about 12 and 16 carbon atoms.
• One commercially available product of this type includes a mixture of alkyl dimethyl benzyl ammonium chlorides wherein about 50% of the surfactant has a C14H29 n-alkyl group, about 40% of the surfactant has a C12H25 n-alkyl group, and about 10% of the surfactant has a C16H33 n-alkyl group. This pro­duct is known per se for its microbiocidal effectiveness.
• the cat­ionic polymers and/or cationic surfactants of this invention are applied directly, preferably by spraying, onto paper machine parts at low concentrations slime and other microbiological deposits on said parts or equipment are significantly reduced or eliminated. More specifically, it has been found that generally such a low concentration of the polymer or surfactant as from about 0.1 parts per million of dilution water will give a deposit-reducing effect. Preferably said amount is from about 5 parts per million of dilution water where continuous treatment is used, while preferably from about 50 parts per million of dilution water is utilized during the application period where the application is intermittent.
• the upper limit this can easily be determined by a person skilled in the art in each specific case, but in general said amount or concentration is kept at as low level as possible to avoid an unnecessary contamination of the paper therewith.
• a preferable upper limit is 500 parts per million of dilution water.
• the polymer or surfactant of this invention is applied, such as by spraying, in aqueous solution directly onto the equipment being treated.
• the aqueous solution containing the cationic polymer and/or surfactant should be substantially free from anionic macromolecules.
• anionic materials include natural materials such as wood lignins, by products of chemical pulping such as sodium lignosulfonates, and synthetic materials such as polyacrylates.
• the polymers and surfactants of this invention are typically supplied as liquid compositions comprising aqueous solutions of the polymer and/or surfactant.
• Polymer concentrations of the com­positions may range from such relatively dilute solutions having polymer concentrations suitable for continuous application up to the solubility or gelling limits of the polymer, but generally the compositions are relatively concentrated for practical shipping and handling purposes.
• the liquid compositions may com­prise additional materials which enhance the dissolution of the polymers so as to allow more concentrated compositions to be ob­tained. As an example of such materials reference can be made to alkoxyethanols such as butoxyethanol. Suitable aqueous composi­tions will generally contain between 5 and 50 percent by weight of the cationic products of this invention. It should also be understood that, if desired, the compounds embodied by this invention can be added in solid form, e.g. as granulates.
• the most appropriate treatment dosage depends on such system factors as the soiling level of the adhesive material, and whether cleaning is continuous or periodic. Even liquid compositions com­prising relatively high concentrations of a polymer of the inven­tion (for example 50%) may be employed at full strength (100% as the liquid composition) for example by spraying the undiluted liquid composition directly onto the machine parts. However, par­ticularly where continuous treatment is practiced, the composi­tions may be advantageously diluted at the treatment location with clean fresh water or other aqueous liquid. Where necessary for water economy, process water may be adequate for dilution.
• the method claimed can be performed continuously in order to continuously control the deposits referred to.
• continuous treatment is not practical and then the treatment with the cationic polymers and surfactants of this in­vention may be periodic.
• aqueous solutions of the polymer or surfactant may be sprayed on the deposited surface un­til said surface is satisfactorily cleaned, and the spraying may then be discontinued until further treatment becomes necessary.
• a commercial paper machine of twin wire type produces news­print paper.
• biocides are added to the white water circulation system of this machine.
• Biocide A Wire chest 24 Slower “slime” build-up than ref 5 % increase in comparison to ref 2.
• Biocide B Shower water tank - 3. Polymer Water to high pressure showers 105 4. Polymer Water to low pressure showers 50
• Biocide A Solution of 5-chloro-2-methyl-4 isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; commercially available as DARACIDE 856 (W R Grace AB, Helsingborg, Sweden)
• Biocide B Dibromonitrilo-propianamide; commercially available as DARACIDE 855 (W R Grace AB, Helsingborg, Sweden)
• Polymer Condensation product of Dicyandiamide-Formaldehyde; commercially available as DARASPERSE 7951 (W R Grace AB, Helsingborg, Sweden)

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Paints Or Removers (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
• Detergent Compositions (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1988
  • 1988-08-11 SE SE8802873A patent/SE467667B/sv not_active IP Right Cessation
• 1989
  • 1989-07-19 NZ NZ229991A patent/NZ229991A/xx unknown
  • 1989-07-27 ZA ZA895715A patent/ZA895715B/xx unknown
  • 1989-08-01 AU AU39190/89A patent/AU615095B2/en not_active Expired
  • 1989-08-03 EP EP19890850245 patent/EP0354889A3/fr not_active Ceased
  • 1989-08-09 JP JP1204933A patent/JPH086279B2/ja not_active Expired - Lifetime
  • 1989-08-10 NO NO893226A patent/NO175402C/no unknown
  • 1989-08-10 CA CA000607955A patent/CA1326317C/fr not_active Expired - Lifetime
  • 1989-08-10 FI FI893788A patent/FI91007C/fi active IP Right Grant

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