Process for coating solvent-free lacquers
AssigneeBayer Aktiengesellschaft
InventorsFreidrich Blomeyer, deceased, Gerhard Mennicken, Walter Uerdingen
Life of this patent
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Abstract
This invention discloses mixtures for use as binders for solvent-free lacquers which are liquid at room temperature, can be prepared in the presence of moisture and have good light stability and resistance to weather. The mixtures contain: (a) at least one organic polyisocyanate which contains aliphatically bound isocyanate groups; (b) at least one polyhydroxyl compound with a molecular weight of 200 to 2000 which is free from ether groups; and (c) 0-40 percent by weight, based on the total mixture of monohydric and/or polyhydric alcohols with a molecular weight below 200; the components of the mixture being used in such quantities that the NCO/OH ratio is between 0.8:1 and 1.2:1.
Claims9
In a process for coating substrates with polyurethane forming lacquers and curing the coating, the improvement wherein a lacquer binder is used which has a solvent-free viscosity of 20 to 100 DIN seconds in DIN cup 4 measured according to DIN 53211 and comprises
- (a) a polyisocyanate component consisting essentially of a polyisocyanate or polyisocyanates having only aliphatically bound isocyanate groups,
- (b) a high molecular weight polyhydroxy component consisting essentially of a polyhydroxy compound or compounds which have molecular weights between 200 and 2000 and do not contain ether groups, and
- (c) 10 to 30 percent by weight, based on the total quantity of binder, of a low molecular weight component comprising monohydric and/or polyhydric alcohols with molecular weights below 200,
- wherein said components are present in quantities corresponding to an NCO to OH ratio of between 0.8:1 to 1.2:1.
A process for coating substrates comprising coating said substrates with a coating composition which is liquid at room temperature and contains a binder which has a solvent-free viscosity of 20 to 100 DIN seconds in DIN cup 4 according to DIN 53211, wherein said binder consists essentially of a mixture of
- (a) a polyisocyanate component consisting essentially of a polyisocyanate or polyisocyanates having only aliphatically bound isocyanate groups,
- (b) a high molecular weight polyhydroxy component consisting essentially of a polyhydroxy compound or compounds which have molecular weights between 200 and 2000 and do not contain ether groups, and
- (c) 10 to 30 percent by weight, based on the total quantity of binder, of a low molecular weight component comprising a mixture of monohydric and polyhydric alcohols with molecular weights below 200 in a ratio of mono to polyhydric of between 3:7 and 7:3,
- wherein said components are present in quantities corresponding to an NCO to OH ratio of between 0.8:1 and 1.2:1, and curing the coating.
In a process for coating substrates with polyurethane forming lacquers and curing the coating, the improvement wherein a lacquer binder is used which has a solvent-free viscosity of 20 to 100 DIN seconds in DIN cup 4 measured according to DIN 53211 and which comprises
- (a) at least one organic polyisocyanate with aliphatically bound isocyanate groups,
- (b) a high molecular weight polyhydroxy component consisting essentially of a polyhydroxy compound or compounds which have molecular weights between 200 and 2000 and do not contain ether groups, and
- (c) 10 to 30 percent by weight, based on the total quantity of binder, of a low molecular weight component comprising monohydric and/or polyhydric alcohols with molecular weights below 200,
- wherein said components are present in quantities corresponding to an NCO to OH ratio of between 0.8:1 and 1.2:1.
Process for coating substrates using coating compositions which are liquid at room temperature and which contain a binder having a solvent-free viscosity of 20 to 100 DIN seconds in DIN cup 4 according to DIN 53211, wherein said binder comprises a mixture of
- (a) tris-(isocyanatohexyl)-biuret,
- (b) a high molecular weight polyhydroxy component consisting essentially of a polyhydroxy compound or compounds which have molecular weights between 200 and 2000 and do not contain ether groups, and
- (c) 0-40 percent by weight, based on the total mixture, of a low molecular weight component comprising monohydric and/or polyhydric alcohols with a molecular weight below 200,
- the components of the mixture being present in quantities corresponding to an NCO/OH ratio of between 0.8:1 and 1.2:1.
Process for coating substrates using coating compositions which are liquid at room temperature and which contain a binder having a solvent-free viscosity of 20 to 100 DIN seconds in DIN cup 4 according to DIN 53211, wherein said binder comprises a mixture of
- (a) approximately 30 to 70 percent by weight of tris-(isocyanatohexyl)-isocyanurate and approximately 70 to 30 percent by weight of bis-(isocyanatohexyl)uretdione,
- (b) a high molecular weight polyhydroxy component consisting essentially of a polyhydroxy compound or compounds which have molecular weights between 200 and 2000 and do not contain ether groups, and
- (c) 0-40 percent by weight, based on the total mixture, of a low molecular weight component comprising monohydric and/or polyhydric alcohols with a molecular weight below 200,
- the components of the mixture being present in quantities corresponding to an NCO/OH ratio of between 0.8:1 and 1.2:1.
Dependencies are inferred from the claim text.