AU593325B2

AU593325B2 – A process for the dry cationization of starch
– Google Patents

AU593325B2 – A process for the dry cationization of starch
– Google Patents
A process for the dry cationization of starch

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Publication number
AU593325B2

AU593325B2
AU68793/87A
AU6879387A
AU593325B2
AU 593325 B2
AU593325 B2
AU 593325B2
AU 68793/87 A
AU68793/87 A
AU 68793/87A
AU 6879387 A
AU6879387 A
AU 6879387A
AU 593325 B2
AU593325 B2
AU 593325B2
Authority
AU
Australia
Prior art keywords
starch
silica
weight
reaction
mixer
Prior art date
1986-02-15
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Ceased

Application number
AU68793/87A
Other versions

AU6879387A
(en

Inventor
Wolfgang Fischer
Michael Huss
Reinhard Dr. Stober
Klaus Dr. Udluft
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Evonik Operations GmbH

Original Assignee
Degussa GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1986-02-15
Filing date
1987-02-13
Publication date
1990-02-08
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1987-02-13
Application filed by Degussa GmbH
filed
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Degussa GmbH

1987-08-20
Publication of AU6879387A
publication
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patent/AU6879387A/en

1990-02-08
Application granted
granted
Critical

1990-02-08
Publication of AU593325B2
publication
Critical
patent/AU593325B2/en

2007-02-13
Anticipated expiration
legal-status
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Status
Ceased
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Classifications

C—CHEMISTRY; METALLURGY

C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON

C08B—POLYSACCHARIDES; DERIVATIVES THEREOF

C08B31/00—Preparation of derivatives of starch

C08B31/08—Ethers

C08B31/12—Ethers having alkyl or cycloalkyl radicals substituted by heteroatoms, e.g. hydroxyalkyl or carboxyalkyl starch

C08B31/125—Ethers having alkyl or cycloalkyl radicals substituted by heteroatoms, e.g. hydroxyalkyl or carboxyalkyl starch having a substituent containing at least one nitrogen atom, e.g. cationic starch

Abstract

A dry process for preparation of cationic starch ethers by reaction of starch with alkylidene epoxides in the presence of water in an alkaline medium at a temperature of 5 DEG to 40 DEG C. in the presence of a finely divided silica.

Description

L
FORM 10 SPRUSON FERGUSON COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION
(ORIGINAL)
FOR OFFICE USE: 6V71/-7 Class Int. Class Complete Specification Lodged: Accepted: Published: muendxnents Mads undar
II
S~~ln 49.
a~d Is C=OPIct for PLWr~LmS.& Priority: Related Art: Name of Applicant: t X Address of Applicant: Actual Inventor(s): DEGUSSA AKTIENGESELLSCHAFT Weissfrauenstrasse Frankfurt (Main), Federal Republic of Germany REINHARD STOBER, WOLFGANG FISCHER, MICHAEL HUSS and KLAUS UDLUFT Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Wales, 2000, Australia Address for Service: Complete Specification for the invention entitled: «A PROCESS FOR THE DRY CATIONIZATION OF STARCH» The following statement is a full description of this invention, including the best method of performing it known to us SBR:eah 158T L i i- ii F~
-I
86 102 VO
ABSTRACT
A process for the dry cationization of starch This invention relates to a dry process for the production of cationic starch ethers by reaction of starch with alkylidene epoxides in the presence of water in alkaline medium at a temperature of from to 40’C in the presence of a finely divided silica.
I t 9
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*I
I~ iii—-i 86 102 VO Degussa Aktiengesellschaft, Weissfrauenstrasse 9, 6000 Frankfurt on Main A process for the dry cationization of starch 4* 4r *1 r
I
t
C
t *4 It ar I C.i 1 This invention relates to a dry process for the production of cationic starch ethers by reaction of starch with alkylidene epoxides in the presence of water in alkaline medium.
5 It is known that starch or starch-containing substances can be reacted with cationic etherifying agents by socalled dry processes. In processes such as these, the reaction is not carried out in an aqueous suspension, but with powder-form starch.
According to US-PS 4 127 563, cationization is carried out with alkylidene halohydrins at a pH value of <9 and at a temperature of from 25 to The reaction of a halohydrin with starch in alkaline medium, but at a temperature at least 30°C below the gelatinization temperature of starch, is claimed in US-PS 3 346 563. EP-PS 31 477 also describes a process for the reaction of starch with alkylidene epoxides which is carried out in the presence of water, calcium hydroxide or calcium oxide at temperatures of from 50 to 120°C. DE-OS 29 35 338 describes a process for the cationization starch. In this case, however, the alkali excess has to be neutralized. According to US-PS 4 281 109, it is advisable to premix the etherifying agent and the alkali or alkalineearth hydroxide and then to mix the resulting premix with ~pas~N. 4 15 J o l k 2 1' the starch. This procedure is said to achieve more uniform and more rapid mixing of the reagents so that, for example, there are no local accumulations of alkali which could lead to swelling of starch. One feature common to all the processes mentioned above is that the etherification reaction mixture has to be stirred until the reaction is over. The reaction naturally takes longer with decreasing temperature. Reaction vessels are occupied for correspondingly long periods and have to be stirred. In addition, losses of yield have to be accepted. The object of the present invention is to provide a process for the production of cationic starch ethers in which despite low reaction temperatures only very little stirring energy has to be applied, reaction vessels are only briefly occupied and very good yields are obtained without any need for sifting. Accordingly, the present invention relates to a process for the dry cationization of starch by reaction of starch with alkylidene epoxides in alkaline medium in the presence of water, characterized in that the reaction is carried out at 5 to 40 0 C in the presence of a Sfinely divided silica. A starch thus prepared has a pH value of >9 by weight suspension) According to the invention, the mixture of starch, alkali or alkaline-earth hydroxide or oxide, silica and alkylidene epoxide, which is generally used in the form F of an aqueous solution, is homogenized in an intensive mixer for between 10 seconds and 25 minutes and preferably for between 20 seconds and 5 minutes, subsequently removed from the circuit and the cationization reaction left to continue to completion in the storage container envisaged, such as a silo for example, or even in the packs intended for shipment.
EL.- 11 ok I I- I3 1 Accordingly, there is no longer any need to expend further mixing energy for further process steps.
In addition, it has been found to be of advantage to carry out the process at a temperature in the range over which the ambient temperature of ordinary warehouses varies, for example as a result of seasonal fluctuations, i.e. at a temperature in the range of from 18 to 30 0 C and more especially at a temperature in the range of from to Tests have shown that the epoxide used reacts off completely. At a temperature of 20 0 C, it is only possible to detect traces of <10 ppm epoxide/kg starch after a period of 7 days. ,Starches produced by the process according to the 15 invention do not contain any coarse fractions and may be used without any need for aftertreatment (sifting) i Suitable intensive mixers, are, for example, 0 1 ploughshare mixers (continuous and non-continuous) and 4 moistening flow mixers (continuous) Native or modified starch or starch-containing substances of any origin may be used for the production oft "of cationic starch ethers by the process according to G the invention. It is of particular advantage to use native wheat, corn, tapioca or potato starch. According to the invention, the starch is etherified with alkylidene epoxides corresponding to the following o general formula CH 2 CH-(CH 2 N (I) 100 u >100 Fv >100 p.
>100 1 >100 i 0.5% 0.6% 1.0% 2.9% 10.3% distribution <100 u 99.5% <100 u 99.4% <100 u 99.0% <100 u 97.1% <100 u 89.7% EXAMPLE 11 According to the invention, the viscosity of starch paste can be changed for the same degree of substitution: Potato starch (DS 0.026) Product of test no. Activator Viscosity 3% starch paste ,a ti o t o I o6, 0 o .0~ 4 t(' *O 0 0 3 1 as 1, but with 2 1.0% PC-3 1.6% PC-2 2.1% PC-4 2.5% PC-5 1800 mPas 1450 mPas 600 mPas 56 mPas o 0rr 00 EXAMPLE 12 Starches cationized by the process according to the invention excellent retention values, as measured by the DDJ test on pulp suspensions consisting of 3 g/l pulp (50% beech sulfite, 10% spruce sulfite, beech sulfate pulp), 21 0 SR and 2 g/l filler (china clay). (D.W.Zunker, A.F. Breazeale, Tappi 66 (1983) 37, K.W. Britt, J.E. unbehend, Tappi 59 (1976) 67, D. Abson, D.F. Brooks, Tappi 68 (1985) 76) IL- 1 Mh I I AIL k t 14 1 DDJ test (dynamic drainage jar) Starch Addition in Fines and filler (based on in filtrate retention solids) in None 0.149 0 Native potato 0.2 0.145 3 starch 0.5 0.149 0 Cationic potato starch (DS 0.031) 0.2 0.026 83 (Example 8) 0.5 0.008 Cationic potato 0.2 0.054 64 starch (DS 0.026) 0.5 0.022 (Example 1) 1.0 0.004 97 This test shows good correlation with the conditions in the papermaking machine. t S" EXAMPLE 13 The viscosity of starch paste can be considerably a At *increased by the addition of 0.5% by weight 3-chloro-2- S, 20 hydroxypropyl dimethylethanolammonium chloride to the cationization reagent 3-chloro-2-hydroxypropyl trimethylammonium chloride or 2,3-epoxypropyl trimethylammonium chloride which, in papermaking, leads to considerably better retention values and to improved properties of the 25 end products. a 44 30 At Potato starch DS 0.026 Viscosity reagent paste) 80 0 C 20 0 C 2,3-epoxypropyl trimethylammonium chloride 153 mPas 918 mPas 0.5% 3-chloro-2-hydroxypropyl ethanolammonium chloride 284 mPas 1450 mPas Cationization is carried out at 20 0 C in the presence of 1.6% by weight activator PC-2. ILL-I iI I IIPiP iii 1a 15 1 EXAMPLE 14 (Potato starch, theor. DS 0.049) A higher yield of the cationization reaction is obtained by carrying out the reaction in the presence of silica. Yield after 6 days at Flow behavior Without Sa 91.4% inadequate (does not flow from 18 mm orifice) 0.50% Sa 93.9% very good (flows from 2.5 mm orifice) (Orifice cups: internal diameter 90 mm, height 42 mm) 15 Sa: spray-dried silica, 190 m 2 /g I I Cc~ti 0 0 a o 01 0 0 a a a o o 0 0t 0 0 00 0 0 0 QQ 0 0 0 0 00 0 us t oi e t Ct L_ ~c r; .i Claims (9) 1. A process for the dry cationization of starch by reaction of starch with alkylidene epoxides in alkaline medium in the presence of water, characterized in that the reaction is carried out at 5 to 40°C in the presence of a finely divided silica. 2. A process as claimed in Claim 1, characterized in that the mixture of starch, alkaline hydroxide or oxide, silica and alkylidene epoxide is homogenized in an intensive mixer for 20 seconds to 25 minutes, removed from the circuit and allowed to finish reacting in the container envisaged for storage. 2: 3. A process as claimed in Claims 1 and 2, characterized *in that alkylidene epoxides corresponding to the following general formula R oo o CH-CH--(CH) -N (I) "aor oa t 0' R2 usd in which n 1, 2 or 3, R 1 R 2 and R 3 may be the same or different and represent 1I-4 alkyl radicals or R 1 repre- sents the benzyl radical and X represents chloride, bromide, sulfate or acetate, are used. :i 1 17 4. A process as claimed in Claim 3, characterized in that the cationization reaction is carried out in the presence of from 0.5 to 5% by weight, based on the epoxides of formula I or II, of a compound corresponding to the following formulae CH 3 CH- CH- CH 2 -CH 3 2 2 N C250H CH CH 2 -CH- CH- CH3 0 C2H25 OAc (III) (IV) (V) *r I f I.r CH 3 CH-CH-CH 2 CH '0 CH 2- t in which G represents chloride, bromide, sulfate or acetate (Ac). A process as claimed in any one of Claims 1 to 4, characterized in that a powder-form mixture of silica, the alkaline hydroxide or oxide and optionally water is used. 6. A process as claimed in any one of Claims 1 to 5, characterized in that a finely divided hydrophilic silica is used. 7. A process as claimed in any one of Claims 1 to 5, characterized in that a finely divided hydrophobic silica is used. 8. A process as claimed in Claim 5 in which the powder-form mixture consists of from 10 to 50% by weight of a hydrophilic silica and of from to 90% by weight of calcium hydroxide or oxide. 9. A process as claimed in Claim 5 in which the powder-form mixture consists of from 10 to 50% by weight of a mixture of hydrophilic and hydrophobic silica, and of from 50 to 90% by weight of calcium hydroxide or oxide, the silica mixture containing up to 20% hydrophobic silica. A process as claimed in any one of Claims 1 to 9, characterized in that a ploughshare mixer is used as the intensive mixer. i. TMR/956u N1_ dak I M- 18 11. A process as claimed in any one of Claims 1 to 10, characterized in that a moistening flow mixer is used as the intensive mixer. 12. A process for the dry cationization of starch substantially as hereinbefore described with reference to any one of the Examples. DATED this EIGHTEENTH day of OCTOBER 1989 Degussa Aktiengesellschaft Patent Attorneys for the Applicant SPRUSON FERGUS,.' ooo o0 o 0 0 o9 00 1 I t TMR/956u 4. 1 AU68793/87A 1986-02-15 1987-02-13 A process for the dry cationization of starch Ceased AU593325B2 (en) Applications Claiming Priority (2) Application Number Priority Date Filing Date Title DE19863604796 DE3604796A1 (en) 1986-02-15 1986-02-15 METHOD FOR DRYING THE STARCH DE3604796 1986-02-15 Publications (2) Publication Number Publication Date AU6879387A AU6879387A (en) 1987-08-20 AU593325B2 true AU593325B2 (en) 1990-02-08 Family ID=6294151 Family Applications (1) Application Number Title Priority Date Filing Date AU68793/87A Ceased AU593325B2 (en) 1986-02-15 1987-02-13 A process for the dry cationization of starch Country Status (11) Country Link US (2) US4785087A (en) EP (1) EP0233336B1 (en) JP (1) JPS62192401A (en) CN (1) CN1043505A (en) AT (1) ATE96808T1 (en) AU (1) AU593325B2 (en) BR (1) BR8606473A (en) DE (2) DE3604796A1 (en) ES (1) ES2044833T3 (en) FI (1) FI82839C (en) ZA (1) ZA87716B (en) Cited By (2) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title AU609504B2 (en) * 1987-08-08 1991-05-02 Degussa A.G. Process for the dry cationization of starch AU629345B2 (en) * 1989-05-31 1992-10-01 Degussa A.G. A method of manufacturing an adjustable-viscosity cationised starch Families Citing this family (33) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title DE3733507A1 (en) * 1987-10-03 1989-04-13 Degussa PROCESS FOR THE PREPARATION OF TERTIAER OR QUATEROUS NITROGEN-CONTAINING CELLULOSE ETHERS NL8800647A (en) * 1988-03-16 1989-10-16 Avebe Coop Verkoop Prod METHOD FOR MANUFACTURING STARCH ETHERS US5349089A (en) 1989-07-07 1994-09-20 National Starch And Chemical Investment Holding Corporation Reagent for preparing polycationic polysaccharides US5227481A (en) * 1989-07-07 1993-07-13 National Starch And Chemical Investment Holding Corporation Cationic polysaccharides and reagents for their preparation US4992536A (en) * 1989-10-31 1991-02-12 National Starch And Chemical Investment Holding Corporation Preparation of polycationic polysaccharides by site selective reaction DE4018287A1 (en) * 1990-06-07 1991-12-12 Sued Chemie Ag Flocculating agent for purificn. of waste water - comprises acid soln. of salts of polyvalent metals and cationic polymeric carbohydrate FR2664603B1 (en) * 1990-07-10 1994-04-29 Roquette Freres METHOD FOR THE ION PERMUTATION OF IONIZED STARCHES AND IONIZED STARCHES THUS OBTAINED. SE502192C2 (en) * 1990-12-11 1995-09-11 Eka Nobel Ab Starch soln. prepn. using cold water - by mixing starch with sufficient shear to break up agglomerates, heating and keeping hot until max. viscosity has passed SE9003954L (en) * 1990-12-11 1992-06-12 Eka Nobel Ab SET FOR MANUFACTURE OF SHEET OR SHAPE CELLULOSA FIBER CONTAINING PRODUCTS US5241061A (en) * 1992-05-27 1993-08-31 The Dow Chemical Company Process for the dry cationization of starch US5912306A (en) * 1992-12-30 1999-06-15 Hercules Incorporated Cationic compounds useful as drainage aids and stabilizers for rosin-based sizing agents FR2732368B1 (en) * 1995-03-31 1997-06-06 Roquette Freres NEW PAPERMAKING PROCESS FR2734005B1 (en) * 1995-05-12 1997-07-18 Roquette Freres COMPOSITION AND METHOD FOR GLUING PAPER KR100226154B1 (en) * 1995-12-29 1999-10-15 이삼우 Method of preparing highly substituted cationic starch FR2743810B1 (en) 1996-01-23 1998-04-10 Roquette Freres MODIFIED CATIONIC POLYSACCHARIDES, BONDING COMPOSITIONS CONTAINING THEM AND METHODS FOR BONDING PLANAR STRUCTURES USING THE SAME DE19717030A1 (en) * 1997-04-23 1998-10-29 Degussa Substituted, powdered natural polymers, a process for their preparation and their use CN1079098C (en) * 1998-04-13 2002-02-13 中国科学院广州化学研究所 Process of producing cold soluble particular cationic starch by predextrination FI114159B (en) * 2002-05-20 2004-08-31 Raisio Chem Oy Procedure for treating starch US20040138438A1 (en) * 2002-10-01 2004-07-15 Fredrik Solhage Cationised polysaccharide product US20040104004A1 (en) * 2002-10-01 2004-06-03 Fredrik Solhage Cationised polysaccharide product NO317844B1 (en) * 2002-11-04 2004-12-20 Yara Int Asa A product for treating water and wastewater and a process for making said product CN1328290C (en) * 2004-12-03 2007-07-25 诸城兴贸玉米开发有限公司 Process for producing cation starch by dry method DE102005020552A1 (en) * 2005-05-03 2006-11-09 Degussa Ag Process for the chemical modification of polysaccharides DE102005020551A1 (en) * 2005-05-03 2006-11-09 Degussa Ag Solid, redispersible emulsion DE102005044189A1 (en) * 2005-09-15 2007-03-22 Degussa Ag Pellets of diacyl peroxide in a polysaccharide matrix CN1990392B (en) * 2005-12-07 2011-04-06 中国科学院成都有机化学有限公司 High substitution quaternary ammonium cationic starch flocculating agent and method for synthesizing same US8304533B2 (en) * 2006-04-24 2012-11-06 BASF SE Ludwigshafen Cationic polysaccharide, its preparation and use EP2199462A1 (en) * 2008-12-18 2010-06-23 Coöperatie Avebe U.A. A process for making paper CN102161708B (en) * 2011-02-24 2012-07-18 广西农垦明阳生化集团股份有限公司 Preparation method of low-viscosity cation starch CN104861211B (en) * 2015-05-06 2017-11-07 金东纸业（江苏）股份有限公司 A kind of preparation method of compound type starch CN104861213B (en) * 2015-05-06 2017-11-07 金东纸业（江苏）股份有限公司 A kind of preparation method of compound type starch CN111172807A (en) * 2020-01-19 2020-05-19 东北林业大学 Method for constructing cationic supramolecular colloid by using native starch granules AU2021405773A1 (en) 2020-12-23 2023-06-29 Mondi Ag Method for producing derivatised starch Family Cites Families (10) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title US3346563A (en) * 1964-08-07 1967-10-10 Staley Mfg Co A E Preparation of quaternary ammonium starch ethers US4070300A (en) * 1973-06-09 1978-01-24 Collo Gmbh Pourable solid filter material, particularly for the removal of unpleasant odors from the air, and a process for its manufacture US4127563A (en) * 1977-06-29 1978-11-28 The United States Of America As Represented By The Secretary Of Agriculture Low pH preparation of cationic starches and flours FR2434821A1 (en) * 1978-08-31 1980-03-28 Roquette Freres PROCESS FOR CATIONIZING STARCH, NOVEL CATIONIZED STARCHES THUS OBTAINED AND APPLICATIONS THEREOF JPS5941646B2 (en) * 1979-08-31 1984-10-08 敷島紡績株式会社 Method for producing cationic starch DE2949886A1 (en) * 1979-12-12 1981-06-19 Degussa Ag, 6000 Frankfurt METHOD FOR THE PRODUCTION OF CATIONIC STARCH KEEPERS US4291315A (en) * 1979-12-28 1981-09-22 International Business Machines Corporation Apparatus for providing a constant density trace of ECG analog signals US4281109A (en) * 1980-03-03 1981-07-28 National Starch And Chemical Corporation Pollution-free cationization of starch US4452978A (en) * 1982-11-19 1984-06-05 A. E. Staley Manufacturing Company Granular starch ethers having reduced pasting temperatures US4464528A (en) * 1982-12-16 1984-08-07 The Dow Chemical Company Process for making cationic starch 1986 1986-02-15 DE DE19863604796 patent/DE3604796A1/en active Granted 1986-12-03 DE DE86116805T patent/DE3689261D1/en not_active Expired - Fee Related 1986-12-03 AT AT86116805T patent/ATE96808T1/en not_active IP Right Cessation 1986-12-03 EP EP86116805A patent/EP0233336B1/en not_active Revoked 1986-12-03 ES ES86116805T patent/ES2044833T3/en not_active Expired - Lifetime 1986-12-29 BR BR8606473A patent/BR8606473A/en not_active IP Right Cessation 1986-12-29 US US06/947,458 patent/US4785087A/en not_active Expired - Lifetime 1987 1987-01-21 FI FI870250A patent/FI82839C/en not_active IP Right Cessation 1987-01-30 ZA ZA87716A patent/ZA87716B/en unknown 1987-02-02 JP JP62020615A patent/JPS62192401A/en active Granted 1987-02-13 AU AU68793/87A patent/AU593325B2/en not_active Ceased 1987-10-29 US US07/113,970 patent/US4812257A/en not_active Expired - Lifetime 1988 1988-12-15 CN CN88108589A patent/CN1043505A/en active Pending Cited By (2) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title AU609504B2 (en) * 1987-08-08 1991-05-02 Degussa A.G. Process for the dry cationization of starch AU629345B2 (en) * 1989-05-31 1992-10-01 Degussa A.G. A method of manufacturing an adjustable-viscosity cationised starch Also Published As Publication number Publication date EP0233336A3 (en) 1988-05-04 ATE96808T1 (en) 1993-11-15 FI82839C (en) 1991-04-25 JPS62192401A (en) 1987-08-24 DE3689261D1 (en) 1993-12-09 EP0233336B1 (en) 1993-11-03 FI870250A0 (en) 1987-01-21 FI82839B (en) 1991-01-15 FI870250A (en) 1987-08-16 AU6879387A (en) 1987-08-20 ZA87716B (en) 1987-09-30 US4785087A (en) 1988-11-15 DE3604796A1 (en) 1987-08-20 US4812257A (en) 1989-03-14 BR8606473A (en) 1987-10-20 ES2044833T3 (en) 1994-01-16 EP0233336A2 (en) 1987-08-26 DE3604796C2 (en) 1987-11-12 JPH0547562B2 (en) 1993-07-19 CN1043505A (en) 1990-07-04 Similar Documents Publication Publication Date Title AU593325B2 (en) 1990-02-08 A process for the dry cationization of starch CN101443363A (en) 2009-05-27 Cationic polysaccharide, its preparation and use US4758282A (en) 1988-07-19 Process for dry cationization of galactomannans CA1098655A (en) 1981-04-07 Low ph preparation of cationic starches and flours US2516633A (en) 1950-07-25 Preparation of starch ethers in original granule form EP0620315B1 (en) 2003-11-12 Paper sizing process and composition therefor US4840705A (en) 1989-06-20 Papermaking method US3854970A (en) 1974-12-17 Cationic starch and condensates for making the same US4981958A (en) 1991-01-01 Method for the dry cationization of starch II KR20010022029A (en) 2001-03-15 Modified cellulose ethers US5001191A (en) 1991-03-19 Process for dry cationization of polyvinyl alcohol JP3037367B2 (en) 2000-04-24 A method for producing cationized starch with controlled viscosity. CA1292979C (en) 1991-12-10 Process for the dry cationization of starch CA1309090C (en) 1992-10-20 Process for the dry cationization of galactomannans EP0542236A1 (en) 1993-05-19 Process for manufacture of cationic starch derivatives using concentrated alkali CA1292980C (en) 1991-12-10 Process for the dry cationization of galactomannans JPH02133695A (en) 1990-05-22 Paper-making process EP0874000A2 (en) 1998-10-28 Natural substituted powdered polymers, a process for production and their applications CN110407947A (en) 2019-11-05 A method of cationic starch is prepared using twin-screw extruder method HU0201072A2 (en) 2002-07-29 Substituted polysaccharide sulfates, method for producing them and their use as high-performance flow agents for cement mixtures Legal Events Date Code Title Description 2000-09-14 MK14 Patent ceased section 143(a) (annual fees not paid) or expired
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