Abstract:
The invention relates to modified polysaccharide ethers having a weight-averaged molecular weight of 40,000 to 500,000 g/mole, zero shear viscosity of more than 10 Pa·s, and pseudo-plasticity of more than 20. These modified polysaccharide ethers are obtainable by reacting cellulose-based polysaccharide ether(s) with at least one mesogenic modification agent or modified polysaccharide ethers, obtainable by reacting polysaccharide ether(s) selected from hydroxypropylmethyl cellulose (HPMC), hydroxyethylmethyl cellulose (HEMC), methyl cellulose, and cellulose ethers with methyl and/or ethyl and/or propyl groups and mixtures thereof, with at least one mesogenic modification agent. These substances can be used to produce gel-like to stable aqueous preparations having viscoelastic flow properties, which are suited for use in the human body, particularly within the scope of ophthalmologic procedures.
Abstract:
The present invention relates to thickener polymers which comprise the following structural elements 1-3: a) as structural feature 1 at least one betainic monomer unit according to the formula below with a proportion by weight of from 0.1 to 99.9% by weight, based on the copolymer in which the mutually independent definitions are as follows: m=integer≧1; R1═H, C1-3 alkyl, —COOH; R2═H, C1-3 alkyl; R3=n- or isoalkylene of the formula —(CxH2x)—, in which x is an integer from 1 to 30; R4=—H, cycloalkyl, n- or isoalkyl, aryl; R5=n- or isoalkylene of the formula —(CyH2y)—, in which y is an integer from 1 to 30; A=—S—, —O—, —NR2, in which R2═H, C1-3 alkyl; b) as structural feature 2 at least one anionically charged monomer unit according to the following formula with a proportion by weight of from 0.1 to 99.9% by weight, based on the copolymer in which the mutually independent definitions are: l=integer≧1; R1═H, C1-3 alkyl, —COOH; R2═H, C1-3 alkyl; R6=—OH, —OOH, —SH, —(CxH2x)—COOH, —(CxH2x)—SO3H, —N (R2)—(CxH2x)—SO3H, in which —(CxH2x)—=n- or isoalkylene and x is an integer from 1 to 30; c) optionally as structural feature 3 one or more non-ionic comonomer units with a proportion by weight of from 0 to 50% by weight, based on the copolymer. When compared with the prior art, the thickener polymers have increased shear resistance in aqueous formulations.
Abstract:
The present invention relates to polyfunctional nitrones (optionally in the form of nitrone-terminated polymers) and to their use as crosslinking agents and matting agents, preferably for producing stable molding compounds, knifing fillers, and use thereof in inks, coatings, and adhesives. Low crosslinking temperatures characterize the invention. Through the use of polyfunctional nitrones it is possible for all unsaturated polymers to be cured, solidified and/or structured at low temperatures, preferably without use of a catalyst. Depending on the amount of nitrone-terminated polymers and/or low molecular mass polyfunctional nitrone used it is possible to exert a strong influence over the optical and the mechanical properties of the coated surfaces. By optical properties are meant, among others, the gloss of the coating systems and the surface structuring, e.g., the matte effect.
Abstract:
A process for producing a water-soluble, hydrolysis-stable, polymerizable polymer, comprising a) a step of copolymerizing a mixture comprising (i) a first copolymerizable monomer comprising at least one optionally protected carboxylic acid group and a first polymerizable organic moiety, and (ii) a second copolymerizable monomer comprising one or more optionally protected primary and/or secondary amino groups and a second polymerizable organic moiety, for obtaining an amino group containing copolymer; b) a step of coupling to the amino group containing copolymer a compound having a polymerizable moiety and a functional group reactive with an amino group of repeating units derived from the second copolymerizable monomer in the amino group containing copolymer obtained in the first step wherein the optionally protected amino group is deprotected, so that polymerizable pendant groups are linked to the backbone by hydrolysis-stable linking groups, and, optionally, a step of deprotecting the protected carboxylic acid group after step (a) or step (b), for obtaining a polymerizable polymer.
Abstract:
The invention relates to a method for producing fatty acid alkanol amides by reacting at least one amine that contains at least one primary or secondary amino group and at least one hydroxyl group with at least one fatty acid to form an ammonium salt, said ammonium salt being subsequently converted into the alkanol amide by means of microwave radiation.
Abstract:
The invention relates to a copolymer, which includes 20 to 95 percent by weight, based on the total weight of the copolymer, of structural units derived from at least one hydrophilic monomer, and 5 to 80 percent by weight, based on the total weight of the copolymer, of structural units derived from at least one monomer according to the general formula I wherein R1, R2 and R3 each independently of each other denote hydrogen or alkyl-, Y: denotes O or NR4 with R4 selected from hydrogen or alkyl-, X: denotes O, S, SO or SO2, S denotes a structural unit selected from CHR5 or (CHR5CHR5O)iCH2, wherein all of the R5 each independently of each other denote hydrogen or alkyl-, n and i independently of each other denote an integer between 1 and 10 and m denotes an integer between 2 and 6, and wherein the copolymer has a water content from 1 to 59 percent by weight based on the total weight of the copolymer. Furthermore, the invention relates to an ophthalmologic composition.
Abstract:
The present invention relates to dental materials composed of calix[n]arenes and also to the use thereof for cements, composites, adhesives and coating materials in the dental field. The materials include (a) 0.5 to 90% by weight of at least one polymerizable calix[n]arene according to formula (I), (b) 0.01 to 5% by weight of initiator, (c) 0 to 90% by weight of at least one additional monomer which can polymerize under cationic and/or radical conditions and/or which can polymerize by ring opening, (d) 0 to 85% by weight of filler, (e) 0.01 to 5% by weight of additive and (f) 0 to 70% by weight of solvent.
Abstract:
The invention relates to a method for producing polymethacrylimides in two steps: 1) radical copolymerization of (meth)acrylamides (A, (Me,H)HC=CHCONHR2) and alkyl(meth)acrylic esters (B) and optionally further ethylenically unsaturated monomers in the presence of an aqueous solvent. The monomers (A) include, in addition to acrylamide and methacrylamide, (meth)acrylamides that are substituted on their nitrogen group (R2<>H). The monomers (B) are the (meth)acrylic esters of secondary or tertiary alcohols, preferably tert. butylmethacrylate. 2) Thermal or catalytic reaction of the copolymers produced in 1) to polymethacrylimide or for R2<>H to N-substituted polymethacrylimides while alkenes are separated.