Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
1999-08-17
2001-02-06
Yoon, Tae (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S509000, C524S537000, C524S812000, C526S304000
Reexamination Certificate
active
06184310
ABSTRACT:
DESCRIPTION
The present invention relates to a process for preparing addition polymers which contain carbamate units and to their use as retention, drainage and flocculation aids and as fixatives in paper-making, as protective colloids for the preparation of aqueous alkyldiketene dispersions and as dispersants for the preparation of aqueous filler slurries.
Vinylamine polymers are prepared by polymerizing acyclic N-vinylcarboxamides, preferably N-vinylformamide, and subsequent hydrolysis of the polymers by the action of acids or bases, cf. U.S. Pat. Nos. 4,421,602, 3,597,314, 4,578,515 and 4,255,548. Polyvinylformamides which contain from 10 to 90% of vinylamine units are used, for example according to U.S. Pat. No. 4,421,602, as retention, flocculation and drainage aids in papermaking and as flocculants for sludges.
EP-B-0 216 387 discloses the use of hydrolyzed copolymers of N-vinylformamide, vinyl acetate, vinyl propionate, C
1
-C
4
-alkyl vinyl ethers, the esters, nitrites and amides of acrylic acid and methacrylic acid and of N-vinylpyrrolidone in papermaking as paper dry strength enhancers. The comonomers incorporated into the copolymers, such as vinyl esters, esters of acrylic acid and methacrylic acid and the nitrites and amides of these carboxylic acids, can likewise be present in hydrolyzed form, if desired. The preferred dry strength enhancers are copolymers of N-vinylformamide and vinyl acetate, whose monomer units are each 30 to 100 mol % hydrolyzed.
EP-B-0 251 182 discloses copolymers containing N-vinylformamide, vinylamine and acrylonitrile units and optionally small proportions of acrylamide and acrylic acid units. These polymers too are obtainable by copolymerizing N-vinylformamide with acrylonitrile and hydrolyzing the copolymers by the action of acids or bases.
The preparation of modified polyvinylamines is likewise known from the literature. For instance, the reaction of polyvinylamine with aliphatic carbonyl chlorides is described in Macromol. Chem. Phys. 195 (1994), 679. U.S. Pat. No. 4,403,072 and U.S. Pat. No. 4 275 002 disclose the reaction of vinylamine polymers with aromatic sulfonyl chlorides to form the corresponding sulfonamides. The reactions are generally carried out in non-aqueous, polar solvents. For this it is necessary first to isolate the polymers, which were synthesized in aqueous solution, and this is costly.
The reaction of low molecular weight amines with haloformic esters is described in Houben-Weyl, Methoden der organischen Chemie, Georg-Thieme-Verlag Stuttgart, volume E4, 149 ff (1983).
Polyethyleneimines are likewise well known substances. They are prepared for example by polymerizing ethyleneimine in an aqueous medium in the presence of small amounts of acids or acid donors, cf. DE-B-1,495,494.
U.S. Pat. No. 3,715,336 discloses copolymers which contain vinylamine units and vinyl alcohol units, these copolymers being obtainable by polymerization of vinyl isocyanate and vinyl acetate, reaction of the copolymers with a C
1
-C
4
alcohol to form carbamate units and partial or complete hydrolysis of the carbamate units to vinylamine units. The copolymers are used for example as flocculants for aqueous suspensions of finely divided inorganic materials and dispersions of organic substances in water.
It is an object of the present invention to provide a technically simple process for preparing addition polymers which contain carbamate units.
We have found that this object is achieved by a process for preparing addition polymers which contain carbamate units, which comprises reacting polyethyleneimines or addition polymers which contain vinylamine units of the formula
where R
1
is hydrogen or C
1
-C
6
-alkyl, with haloformic esters.
The resulting carbamate-functionalized polyethyleneimines or vinylamine polymers are used as retention, drainage and flocculation aids and as fixatives in papermaking, as protective colloids for the preparation of aqueous alkyldiketene dispersions and as dispersants for the preparation of aqueous filler slurries.
Polyethyleneimines are known. A process for their preparation was cited above. The process of the invention can be carried out using virtually any polyethyleneimine, but preference is given to water-soluble polyethyleneimines having, for example, molar masses from 200 to 2 million, preferably from 200 to 500,000. Particular preference is given to using polyethyleneimines having molar masses from 500 to 100,000.
Addition polymers containing vinylamine units are likewise known. References describing suitable polymers of this kind were cited above.
Polymers containing vinylamine units can be polymerized for example from open-chain N-vinylcarboxamides of the formula
where R
1
and R
2
are identical or different and each is hydrogen or C
1
-C
6
-alkyl. Examples of suitable monomers are N-vinylformamide (R
1
═R
2
═H in the formula I), N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinyl-N-methylpropionamide and N-vinylpropionamide. The polymers can be prepared by polymerizing the aforementioned monomers alone, mixed with each other or together with other monoethylenically unsaturated monomers. Homo- or copolymers of N-vinylformamide are preferred as starting material.
Suitable monoethylenically unsaturated monomers for copolymerization with N-vinylcarboxamides include all compounds copolymerizable therewith. Examples thereof are vinyl esters of saturated carboxylic acids of from 1 to 6 carbon atoms such as vinyl formate, vinyl acetate, vinyl propionate and vinyl butyrate. Further suitable comonomers are ethylenically unsaturated C
3
-C
6
-carboxylic acids, for example acrylic acid, methacrylic acid, maleic acid, crotonic acid, itaconic acid and vinylacetic acid and also their alkali metal and alkaline earth metal salts, esters, amides and nitriles, for example methyl acrylate, methyl methacrylate, ethyl acrylate and ethyl methacrylate. Further suitable carboxylic esters are derived from glycols or polyalkylene glycols subject to the proviso that only one OH group is esterified in each case, for example hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate and also diacrylic monoesters of polyalkylene glycols having a molar mass from 500 to 10,000. Further suitable comonomers are esters of ethylenically unsaturated carboxylic acids with aminoalcohols, for example dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, diethylaminopropyl acrylate, dimethylaminobutyl acrylate and diethylaminobutyl acrylate. The basic acrylates can be used in the form of the free bases, in the form of the salts with mineral acids such as hydrochloric acid, sulfuric acid or nitric acid, in the form of the salts with organic acids such as formic acid, acetic acid, propionic acid or sulfonic acid or in quaternized form. Examples of suitable quaternizing agents are dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and benzyl chloride.
Further suitable comonomers are amides of ethylenically unsaturated carboxylic acids such as acrylamide, methacrylamide and also N-alkyl monoamides and -diamides of monoethylenically unsaturated carboxylic acids with alkyl radicals of from 1 to 6 carbon atoms, for example N-methylacrylamide, N,N-dimethylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N-propylacrylamide and tertbutylacrylamide and also basic (meth)acrylamides, for example dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide, diethylaminoethylacrylamide, diethylaminoethylmethacrylamide, dimethylaminopropylacrylamide, diethylaminopropylacrylamide, dimethylaminopropylmethacrylamide and diethylaminopropylmethacrylamide.
Further suitable comonomers are N-vinylpyrrolidone, N-vinylcaprolactam, acrylonitrile, methacrylonitrile, N-vinylimidazole and also substituted N-vinylimidazoles, for example N-vinyl-2-methylimidazole,
Lorencak Primoz
Niessner Manfred
Stamm Armin
Utecht Jens
Weiguny Sabine
BASF - Aktiengesellschaft
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Yoon Tae
LandOfFree
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