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
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
• • 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
  • D21H3/00—Paper or cardboard prepared by adding substances to the pulp or to the formed web on the paper-making machine and by applying substances to finished paper or cardboard (on the paper-making machine), also when the intention is to impregnate at least a part of the paper body

Definitions

• Chemical additives are typically used during papermaking processes to improve the strength properties of paper and paperboard.
• the primary purpose of such chemical additives is to enhance interfiber bonding in the paper sheet.
• Strength additives enable the papermaker to use less pulp, less expensive pulp and/or more filler while making a sufficiently strong, stiff and opaque paper product.
• refining can be reduced while maintaining paper strength, resulting in energy savings and increased production.
• Certain agents provide additional strength to paper when wet. These agents are particularly important to paper grades such as tissue, towel, board, currency, and many others.
• strength additives There are many different chemical additives that have been utilized as strength additives.
• Conventional strength additives include starch, vegetable gums, carboxymethyl cellulose, urea-formaldehyde resins, melamine-formaldehyde resins, acrylamide copolymers and polyamidoamine-epichlorohydrin resins.
• U. S Patent No. 3,556,932 to Coscia discloses water-soluble glyoxalated acrylamide copolymers as strength additives.
• the acrylamide copolymers are prepared by the solution copolymerization of acrylamide with a cationic monomer such as diallyldimethylammonium chloride.
• the polymers are subsequently reacted with glyoxal in a dilute, aqueous solution to impart -CONHCHOHCHO functionalities onto the polymer and to increase the molecular weight of the polymer through glyoxal cross ⁇ links.
• the resulting resins are used extensively as dry strength and wet strength additives in papermaking industries.
• 3,311 ,594 discloses the manufacture and use of polyamidoamine/epichlorohydrin (PAE) resins as wet strength additives for paper.
• the resins are prepared by reacting epichlorohydrin with polyamidoamines.
• the PAE resins also impart limited dry strength to paper.
• PAE resins impart vast wet strength to paper, which results in papers containing these resins difficult to repulp, PAE resins are unsuitable for use as dry strength resins in the production of recyclable paper.
• the invention relates to a composition
• a composition comprising a functionalized water-soluble, cationic, thermosetting, cellulose reactive polymer with a doubly structured backbone that is the reaction product of: (a) a copolymerized (i) acrylamide component, (ii) cationic co-monomer component and (iii) at least one multifunctional crosslinking monomer component; and (b) a cellulose reactive agent component; such that the acrylamide component, the cationic co-monomer component, the multifunctional crosslinking monomer component, and the cellulose reactive agent component are in an amount sufficient amount to produce a polymer that imparts strength to a fibrous substrate when the polymer is added to paper stock during a papermaking process.
• the invention is based on the discovery that by adding a multifun ⁇ ctional crosslinking monomer component during copolymerization of (i) an acrylamide component, and (ii) a cationic co-monomer component, forming a structured backbone and then subjecting the resulting polymer to reaction with a cellulose reactive agent component and forming a polymer with a doubly structured backbone, it is now possible to form a polymer that has improved performance, as compared to a polymer that does not have doubly structured backbone. This is a remarkable discovery, because it would be unexpected that subjecting the backbone to further structuring would affect the polymer's performance.
• multifunctional crosslinking monomer component includes bifunctional monomers as well as multifunctional monomers.
• all numbers or expressions referring to quantities of ingredients, reaction conditions, etc., used in the specification and claims are to be understood as modified in all instances by the term "about.”
• Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.
• the acrylamide component includes those polymers formed from acrylamide and/or methacrylamide or an acrylamide copolymer containing acrylamide and/or methacrylamide as a predominant component among all monomers making up the copolymer.
• the acrylamide polymer When employed as a paper strength agent, however, the acrylamide polymer preferably contains acrylamide and/or methacrylamide in a proportion of 50 mole % or more, or more particularly from 74 to 99.97 mole %, or from 94 to 99.98 mole %.
• the amount of the acrylamide component generally ranges from 70 to 99%, based on the total weight of the copolymer. In one embodiment, the acrylamide component ranges from 75 to 95%.
• acrylamide comonomer of the structured polymers may be replaced by other comonomers copolymerizable with the acrylamide.
• Such comonomers include acrylic acid, acrylic ester such as ethyl acrylate, butyl acrylate, methylmeth- acrylate, 2-ethylhexyl acrylate etc., acrylonitrile, N, N'-dimethyl acrylamide, N-tert-butyl acrylamide, 2-hydroxylethyl acrylate, styrene, vinylbenzene sulfonic, vinyl pyrrolidon.
• the cationic comonomer is generally any cationic comonomer, which when used in accordance to the invention, produces a polymer in accordance to the invention.
• suitable cationic co-monomers include but are not limited to diallyl dimethylammonium chloride, acryloyloxytrimethylammonium chloride, methacryloyloxytrimethylam- monium chloride, methacrylamidopropyl trimethylammonium chloride, 1- methacryloyl-4-methyl piperazine, and combinations thereof.
• the amount of the cationic monomer generally ranges from 1 to 30%, or from 5 to 25% based on the total weight of the copolymer.
• the polymer may also be rendered cationic through reaction of the acrylamide polymer such as the Hofmann degradation.
• the multifunctional crosslinking monomer component can vary.
• suitable monomers include but are not limited to methylene- bisacrylamide; methylenebismethacrylamide; triallylammonium chloride; tetraallylammonium chloride; polyethyleneglycol diacrylate; polyethylene- glycol dimethacrylate; N-vinyl acrylamide; divinylbenzene; tetra (ethylene glycol) diacrylate; dimethylallylaminoethylacrylate ammonium chloride; diallyloxyacetic acid, Na salt; diallyloctylamide; trimethylolpropane ethoxylate triacrylate; N-allylacrylamide N-methylallylacrylamide, and combinations thereof.
• the amount of the multifunctional crosslinking component varies. Examples of suitable monomers can be found in WO 97/18167 and U.S. Pat. No. 4,950,725, incorporated herein by reference in its entirety.
• the amount is at least 20 ppm, e.g., from 20 to 20,000 ppm, or from 100 to 1 ,000 ppm based on the total weight of the polymer.
• the cellulose reactive agent component can be any agent, , which when used in accordance to the invention, produces a polymer with a doubly structured backbone, such that the polymer imparts strength to a fibrous substrate when the polymer is added to paper stock during a papermaking process.
• Suitable cellulose reactive agents include and are not limited to the group consisting of glyoxal, glutaralde- hyde, furan dialdehyde, 2-hydroxyadipaldehyde, succinaldehyde, dialde- hyde starch, diepoxy compounds, and combinations thereof.
• the use of the cellulose reactive agents imparts useful functionalization to the polymers.
• Glyoxalation, for instance, of the structured-branched polyacrylamide introduces CHO functionalities into the polymer and also increases the molecular weight by introducing cross- linking into the polymer structure.
• the structuring and branching of the polymer may additionally effect the degree of glyoxalation and thereby, the polymer performance.
• the glyoxalated structured-branched polyacrylamides exhibit improvement of the properties of strength for paper over the conventional glyoxalated polyacrylamides.
• the amount of cellulose reactive agent can vary with application and can range from 10 to 100%, or from 40 to 50% based on the total weight of the backbone copolymer.
• the molecular weight of the backbone can vary.
• the backbone has a molecular weight, prior to reaction with the cellulose reactive agent component, ranging from 1,000 to 100,000 daltons, preferably 1 ,500 to 30,000 daltons. All molecular weights herein are weight average.
• the bulk viscosity of the copolymer can vary, depending on application. Generally, the viscosity of the copolymer is in the range of 10- 5,000 cps, or more particularly from 150-500 cps at 40% total solids.
• the chain transfer agent is used in the range of 0 to15%, preferred range from 0-10.0%, by weight, based on the total weight of the copolymer.
• the ratio of cellulose reactive units to acrylamide units can range from 0.1-0.5:1.0, respectively.
• the chain transfer agent is an optional component and can include any chain transfer agent, which when used in conjunction with the invention, produces a doubly structured backbone, such that the polymer imparts strength to a fibrous substrate when the polymer is added to paper stock during a papermaking process.
• suitable transfer agents are selected from the group consisting of 2-mercaptoethanol; lactic acid; isopropyl alcohol; thioacids; and sodium hypophosphite.
• Preferred chain transfer agents are 2-mercaptoethanol, lactic acid, and isopropyl alcohol.
• the amounts of transfer agent can vary. Generally, such a transfer agent is present in an amount ranging from 0 to 15%, or more particularly from 0 to 10%.
• the polymers of the invention are cationic and made typically by free radical polymerization.
• the cationicity of the polymer can vary.
• the polymer is cationic due to a polymer reaction such as the Hofmann degradation.
• the polymers can include anionic and non-ionic functionalities and, as such, the polymers can include amphoteric polymers.
• the invention provides a process for making a polymer that involves the steps of (a) copolymerizing an acrylamide component and a cationic monomer component with at least one multifunctional crosslinking monomer component, and thereby forming a structured cationic branched polyacrylamide with a structured backbone; (b) reacting the structured- branched polyacrylamide with a cellulose reactive agent component, and thereby forming a functionalized water-soluble, cationic, thermosetting, and cellulose reactive polymer with a doubly structured backbone; such that the acrylamide component, the cationic co-monomer component, the multifunctional crosslinking monomer component, and the cellulose reactive agent component are in an amount sufficient to produce a polymer that imparts strength to a fibrous substrate when the polymer is added to paper stock during a papermaking process.
• the polymers of the invention can also contain anionic, and nonionic groups. Controlling the level of crosslinker and, optionally, a chain transfer agent, can control the degree of
• the process is carried out in the presence of an initiator component and a suitable solvent component under conditions that produce the water- soluble, cationic, thermosetting, and cellulose reactive polymer.
• Any conventional initiator may be employed to initiate polymerization, including thermal, redox and ultraviolet radiation.
• suitable initiators include and are not limited to azobisisobutyronitrile; sodium sulfite; sodium metabisulf ⁇ te;2,2'-azobis(2-methyl-2-amidinopropane) dihydrochloride; ammonium persulfate and ferrous ammonium sulfate hexahydrate.
• ammonium persulfate / sodium metabisulfite, and combinations thereof can be used.
• Organic peroxides may also be employed for polymerizing ethylenically unsaturated monomers.
• a particularly preferred initiator for the purpose of this invention is ammonium persulfate / sodium metabisulfite. See Modern Plastics Encyclopedia/88, McGraw Hill, October 1987, pp. 165-168.
• the solids of the backbone polymer can differ.
• the backbone polymer solids during functionali ⁇ zation is from 4 to 15%, or more particularly from 5 to 10%.
• the fibrous substrate is generally a paper sheet made from a suitable paper slurry (furnish).
• the furnish from which the fibrous substrate is made can include any furnish that produces a fibrous substrate suitable for this invention.
• Furnishes for instance, can include tissue furnishes, towel furnishes, wet laid furnishes, virgin or recycle furnishes or treated cellulosic furnishes.
• the number of fibrous substrates in a paper product can vary.
• the paper product can have more than one fibrous substrate.
• the paper product has two fibrous substrates, e.g., a two-ply paper product.
• the paper product can have more than two fibrous substrates.
• the invention provides a method that involves the steps of (a) providing paper stock; (b) adding to the paper stock a functionalized water-soluble, cationic, thermosetting, and cellulose reactive polymer that is the reaction product of: (1) a copolymerized (i) acrylamide component, (ii) cationic co-monomer component and (iii) at least one multifunctional crosslinking monomer component; and (2) a cellulose reactive agent component; and (3) forming a web from the paper stock; such that the acrylamide component, the cationic co-monomer component, the multifunctional crosslinking monomer component, and the cellulose reactive agent component are in an amount sufficient amount to produce a polymer that imparts strength to a fibrous substrate when the polymer is added to paper stock during a papermaking process.
• the polymer can be added to a furnish at various papermaking pHs, depending on the application.
• the polymer is added to the fiber furnish with papermaking pH ranging from 3 to 10.
• the pH ranges from 5 to 7.
• the benefits of cellulose reactive functionalized glyoxalated structured polyacrylamides tend to be more visible in the strength of the paper, particularly recycled paper.
• the glyoxalated structured polyacrylamides are readily adsorbed to cellulose fiber at pH values within the range of 3.0-8.0.
• the resins provide strength to paper by forming hydrogen bonds and covalent bonds as well as ionic bonds with cellulose fiber.
• the amounts at which the composition of the invention is used can also vary, depending on the application.
• the polymer is added to the fiber furnish at a dose of from 0.5 to 20 Ib/ton (0.25 - 10 kg/ metric ton), or more particularly from 2 to 13 Ib/ton (1 - 6.5 kg/ metric ton) dry polymer solids based on dry fiber.
• Ib/ton 0.25 - 10 kg/ metric ton
• the improved dry strength additives of the invention for instance, better enable papermakers to use less pulp, less expensive pulp and/or more filler while making sufficiently strong, stiff and opaque paper product, as compared to ordinary compositions and methods.
• refining can be reduced while maintaining paper strength, resulting in energy savings and increased production.
• the improved wet strength allows papermakers to make higher wet strength paper or use lower chemical dosages incurring cost efficiencies and improved machine runnability.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Paper (AREA)
• Graft Or Block Polymers (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 2005
  • 2005-04-19 WO PCT/US2005/013333 patent/WO2006016906A1/en not_active Ceased
  • 2005-04-19 AU AU2005272167A patent/AU2005272167A1/en not_active Abandoned
  • 2005-04-19 MX MX2007000123A patent/MX2007000123A/es not_active Application Discontinuation
  • 2005-04-19 BR BRPI0513054-9A patent/BRPI0513054A/pt not_active IP Right Cessation
  • 2005-04-19 US US11/571,768 patent/US20090071618A1/en not_active Abandoned
  • 2005-04-19 EP EP05737437A patent/EP1828479A1/en not_active Withdrawn
  • 2005-04-19 KR KR1020077000472A patent/KR20070100220A/ko not_active Withdrawn
  • 2005-04-19 RU RU2007104780/12A patent/RU2007104780A/ru not_active Application Discontinuation
  • 2005-04-19 CN CNA2005800224389A patent/CN101048548A/zh active Pending
  • 2005-04-19 CA CA002570146A patent/CA2570146A1/en not_active Abandoned
  • 2005-04-19 JP JP2007520295A patent/JP2008506044A/ja not_active Withdrawn
  • 2005-05-17 TW TW094115926A patent/TW200609252A/zh unknown
• 2006
  • 2006-12-11 IL IL179982A patent/IL179982A0/en unknown
• 2007
  • 2007-02-06 NO NO20070679A patent/NO20070679L/no not_active Application Discontinuation

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