Plasticizer Free Curing Composition
AssigneeChemtura Corporation
InventorsTHOMAS R. DOYLE, YUJIE DING, KEVIN JACKSON, RONALD O. ROSENBERG
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Abstract
Plasticizer free curing compositions comprising small particle size complexes of methylenedianiline and an alkali salt, e.g. a 3:1 coordination complex of MDA/alkali salt, with average diameter 60 micron or less, often 20 micron or less, e.g., 10 microns or less, dispersed in a volatile, non-polar, organic solvent are prepared. Stable one pack urethane compositions comprising the plasticizer free curing compositions and polyurethane prepolymers are prepared, which exhibit excellent storage stability and overcome many of the drawbacks encountered when using MDA complexes dispersed in plasticizers such as high boiling aromatic and alkyl di-esters.
Claims21
A curing composition comprising:
- an inert liquid carrier having a polarity index of from 0 to about 3.7 and a boiling point at atmospheric pressure of 160° C. or less;
- and
- from 10 to 90 wt %, based on the total weight of the curing composition of a 3:1 coordination complex of 4,4′-methylenedianiline and an alkali metal salt formed as solid particles having an average diameter of from 1 to 50 μm,
- wherein the curing composition comprises less than 1 wt % of a plasticizer selected from the group consisting of esters of polycarboxylic acids and monohydric alcohols or phenols, esters of polyols and monocarboxylic acids, triesters of phosphoric acid, aromatic hydrocarbons with a boiling point of over 200° C. and aliphatic hydrocarbons with a boiling point of over 200° C.
A one pack urethane composition comprising:
- an isocyanate terminated prepolymer, and
- particles of a coordination complex of 4,4′-methylenedianiline and an alkali metal salt having an average diameter of from 1 to 50 μm, and
- less than 5 wt %, e.g., 2% or less, of an organic liquid having a polarity index of from 0 to about 3.0 and a boiling point at atmospheric pressure of 160° C. or less,
- wherein the curing composition comprises less than 1 wt % of a plasticizer selected from the group consisting of esters of polycarboxylic acids and monohydric alcohols or phenols, esters of polyols and monocarboxylic acids, triesters of phosphoric acid, aromatic hydrocarbons with a boiling point of over 200° C. and aliphatic hydrocarbons with a boiling point of over 200° C.
A process for preparing a curing composition comprising an inert liquid carrier having a polarity index of from 0 to about 3.7 and a boiling point at atmospheric pressure of 160° C. or less, and a coordination complex of 4,4′-methylenedianiline and an alkali metal salt, said process comprising
- adding 4,4′-methylenedianiline to a mixture comprising
- i) an alkali metal salt selected from the group consisting of, potassium chloride, potassium bromide, potassium iodide, sodium chloride, sodium bromide, sodium iodide, lithium chloride, lithium bromide, lithium iodide;
- ii) one or more inert liquid carrier inert liquid carrier having a polarity index of from 0 to about 3.7 and a boiling point at atmospheric pressure of 160° C. or less;
- iii) a surfactant:
- and
- iv) brine and/or water,
- wherein there is present at any point during the process less than 1.0 wt % plasticizer selected from the group consisting of esters of polycarboxylic acids and monohydric alcohols or phenols, esters of polyols and monocarboxylic acids, triesters of phosphoric acid, aromatic hydrocarbons with a boiling point of over 200° C. and aliphatic hydrocarbons with a boiling point of over 200° C., and
- wherein the coordination complex of 4,4′-methylene dianiline and an alkali metal salt obtained by the process without grinding has an average diameter of less than 50 microns.
The process of 16, wherein after removal of some or all of the water, an isocyanate compound is added to react with some or all of the residual methylenedianiline.
Dependencies are inferred from the claim text.