Controllable filler prefloculation using a dual polymer system
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
D21H-017/33
D21H-017/63
D21H-017/67
C09C-001/02
C09C-001/42
C09C-003/00
출원번호
US-0449888
(2012-04-18)
등록번호
US-8747617
(2014-06-10)
발명자
/ 주소
Cheng, Weiguo
Gray, Ross T.
출원인 / 주소
Nalco Company
대리인 / 주소
Carlsen, Benjamin E.
인용정보
피인용 횟수 :
5인용 특허 :
31
초록▼
A method of preparing a stable dispersion of flocculated filler particles for use in papermaking processes comprises sequential addition of a first flocculating agent to an aqueous dispersion of filler particles followed by shearing of the dispersion, followed by addition of a second flocculating ag
A method of preparing a stable dispersion of flocculated filler particles for use in papermaking processes comprises sequential addition of a first flocculating agent to an aqueous dispersion of filler particles followed by shearing of the dispersion, followed by addition of a second flocculating agent to the dispersion and further shearing of the resultant filler flocs to the desired particle size resulting in shear resistant filler flocs with a defined and controllable size distribution. In addition, a neutralizing coagulant can be added to the dispersion to partially or completely neutralize the charge of the filler before the first flocculating agent is added.
대표청구항▼
1. A method of preparing a stable dispersion of flocculated filler particles having a specific particle size distribution for use in papermaking processes comprising a) providing an aqueous dispersion of filler particles;b) adding a first flocculating agent to the dispersion in an amount sufficient
1. A method of preparing a stable dispersion of flocculated filler particles having a specific particle size distribution for use in papermaking processes comprising a) providing an aqueous dispersion of filler particles;b) adding a first flocculating agent to the dispersion in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles, and the first flocculating agent being amphoteric;c) adding a second flocculating agent to the dispersion in an amount sufficient to initiate flocculation of the filler particles in the presence of the first flocculating agent wherein the second flocculating agent has opposite charge to the net charge of the first amphoteric flocculating agent;d) shearing the flocculated dispersion to provide a dispersion of filler flocs having the desired particle size;e) flocculating the filler particles prior to adding them to a paper stock and wherein no paper stock is present during the flocculation; andt) adding the filler particles to a paper stock. 2. The method of claim 1 wherein the filler flocs have a median particle size of 10-100 μm. 3. The method of claim 1 wherein the filler is selected from the group consisting of precipitated calcium carbonate, ground calcium carbonate, kaolin clay, talc, titanium dioxide, alumina trihydrate, barium sulfate and magnesium hydroxide, and mixtures thereof. 4. The method of claim 1 wherein the first flocculating agent has net anionic charge. 5. The method of claim 4 wherein the second flocculating agent is cationic, selected from the group consisting of copolymers and terpolymers of (meth)acrylamide with dimethylaminoethyl methacrylate (DMAEM), dimethylaminoethyl acrylate (DMAEA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl methacrylate (DEAEM) or their quaternary ammonium forms made with dimethyl sulfate, methyl chloride or benzyl chloride, and mixtures thereof. 6. The method of claim 5 wherein the second flocculating agent is acrylamide-dimethylaminoethyl acrylate methyl chloride quaternary copolymer having a cationic charge of 10-50 mole percent and a RSV of at least 15 dL/g. 7. The method of claim 4 wherein the second flocculating agent is a homopolymer of diallyl dimethyl ammonium chloride having an RSV of 0.1-2 dL/g. 8. The method of claim 1 further comprising adding one or more microparticles to the flocculated dispersion after addition of the second flocculating agent. 9. The method of claim 1 wherein the filler is anionically dispersed and a low molecular weight, cationic coagulant is added to the dispersion to at least partially neutralize its anionic charge prior to the addition of the first flocculating agent. 10. A method of papermaking comprising the use of filler, the method comprising the steps of: providing an aqueous dispersion of filler particles, at least one dry strength aid, and cellulose fiber stock,treating the filler particles by the steps of:a) adding a first flocculating agent to the dispersion in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles, and the first flocculating agent being amphoteric;b) adding a second flocculating agent to the dispersion in an amount sufficient to initiate flocculation of the filler particles in the presence of the first flocculating agent wherein the second flocculating agent has opposite charge to the net charge of the first amphoteric flocculating agent;c) shearing the flocculated dispersion to provide a dispersion of filler flocs having the desired particle size;d) flocculating the filler particles prior to adding them to a paper stock and wherein no paper stock is present during the flocculation,then combining the filler particles with the cellulose fiber stock,treating the combination with at least one dry strength aid, andforming a paper mat from the combination,wherein at least 10% of the filler particles are in a dispersed form using a high anionically charged dispersant,the cellulose fiber stock comprises a plurality of cellulose fibers and water, andthe treatment enhances the performance of the dry strength aid in the paper mat. 11. The method of claim 10 wherein the filler flocs have a median particle size of 10-100 μm. 12. The method of claim 10 wherein the filler is selected from the group consisting of precipitated calcium carbonate, ground calcium carbonate, kaolin clay, talc, titanium dioxide, alumina trihydrate, barium sulfate and magnesium hydroxide, and mixtures thereof. 13. The method of claim 10 wherein the first flocculating agent has net anionic charge. 14. The method of claim 13 wherein the second flocculating agent is cationic, selected from the group consisting of copolymers and terpolymers of (meth)acrylamide with dimethylaminoethyl methacrylate (DMAEM), dimethylaminoethyl acrylate (DMAEA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl methacrylate (DEAEM) or their quaternary ammonium forms made with dimethyl sulfate, methyl chloride or benzyl chloride, and mixtures thereof. 15. The method of claim 13 wherein the second flocculating agent is acrylamide-dimethylaminoethyl acrylate methyl chloride quaternary copolymer having a cationic charge of 10-50 mole percent and a RSV of at least 15 dL/g. 16. The method of claim 13 wherein the second flocculating agent is a homopolymer of diallyl dimethyl ammonium chloride having an RSV of 0.1-2 dL/g. 17. The method of claim 10 further comprising adding one or more microparticles to the flocculated dispersion after addition of the second flocculating agent. 18. The method of claim 10 wherein the filler is anionically dispersed and a low molecular weight, cationic coagulant is added to the dispersion to at least partially neutralize its anionic charge prior to the addition of the first flocculating agent.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (31)
Haehnle, Hans-Joachim; Esser, Anton; Braig, Volker; Blum, Rainer; Baumann, Peter; Dupuis, Jacques; Neutzner, Josef, Aqueous composition and use thereof for paper production.
Esser, Anton; Braig, Volker; Wendker, Martin; Blum, Rainer; Baumann, Peter; Neutzner, Josef; Dupuis, Jacques; Haehnle, Hans-Joachim, Aqueous slurries of finely divided fillers, their preparation and their use for the production of filler-containing papers.
Clitherow Barbara M. (Harpenden GBX) Dean Trevor W. R. (Arlesey GBX) Gascoigne John A. (Hitchin GBX) Van Issum Bernhard E. (Geneva CHX), Filler compositions and their use in papermaking.
Pillai Krishnan J. (Aurora IL) Connelly Lawrence J. (Oak Lawn IL) Gustafson William K. (Sandy UT), Method of dewatering a wet process phosphoric acid slurry.
Riddell Martin C. (15 Nurseries Rd. Kidlington ; Oxfordshire GB2) Waring Ian M. (Johannesburg ZAX), Paper manufacture employing filler and acrylamide polymer conglomerates.
Just Ernst K. (Wilmington DE) Nickol Robert G. (Wilmington DE), Phosphated, oxidized starch and use of same as dispersant in aqueous solutions and coating for lithography.
Pruszynski Przemyslaw,CAX ; Jakubowski Regina,CAX ; Armstrong John R.,CAX ; Rosencrance Scott W., Selective retention of filling components and improved control of sheet properties by enhancing additive pretreatment.
Castro, David J.; Lowe, Robert M.; Liu, Mei, Method of increasing paper bulk strength by using a diallylamine acrylamide copolymer in a size press formulation containing starch.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.