Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From reactant having at least one -n=c=x group as well as...
Reexamination Certificate
2001-03-13
2003-10-21
Sergent, Rabon (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From reactant having at least one -n=c=x group as well as...
C528S073000, C528S085000
Reexamination Certificate
active
06635736
ABSTRACT:
This application claims priority of European Application No. 00200883, filed on Mar. 13, 2000.
FIELD OF THE INVENTION
The field of art to which this invention pertains is that relating to a new composition based on an isocyanate-functional compound, an isocyanate-reactive compound, and a co-catalyst comprising a phosphine and a Michael acceptor.
BACKGROUND OF THE INVENTION
There are many publications that disclose compositions comprising compounds capable of cross-linking or curing under appropriate conditions, such as when mixed with a catalyst, and their use, particularly as coating compositions.
For example, U.S. Pat. No. 5,084,536 discloses a coating composition comprising:
(a) compounds containing at least two unsaturated groups,
(b) compounds containing at least two groups having active hydrogen atoms of the type -SH, and
(c) a catalyst selected from, among others, phosphanes.
U.S. Pat. No. 3,729,404 discloses a curable composition comprising a polyene containing at least two reactive unsaturated carbon to carbon bonds per molecule and a polythiol containing at least two thiol groups per molecule. The curing takes place in the presence of a phosphine or phosphite.
U.S. Pat. No. 4,753,825 discloses isocyanate cross-linking with mercaptan groups under the influence of a vaporous amine catalyst to cure the coating composition.
EP-A-0 068 454 discloses a multi-pack coating composition comprising:
(a) an isocyanate component,
(b) an active hydrogen component, such as polythiol, and
(c) a Lewis base, such as tertiary phosphane.
Coatings used for painting various substrates, such as motor vehicles, are required to have physical properties such as good hardness, good mechanical strength, high drying rate, acceptable pot life, and good resistance to water, acids, and solvents. The coatings are also required to have good appearance properties, which means that films must be smooth and have a high gloss and high distinctness of image (DOI). It is also desirable that all properties be retained under prolonged outdoor weathering.
We have found new compositions that are superior to the prior art compositions with regard to achieving some or all of the above desired properties.
SUMMARY OF THE INVENTION
In brief summary, our invention is a composition comprising:
a) at least one isocyanate-functional compound comprising at least two isocyanate groups,
b) at least one isocyanate-reactive compound comprising at least two isocyanate-reactive groups selected from mercapto groups, hydroxyl groups, and mixtures thereof, and
c) a co-catalyst comprising a phosphine and a Michael acceptor.
In a second embodiment, our invention is a method of coating a substrate comprising coating the substrate with the above composition.
In a third embodiment, our invention is a substrate coated with the composition of the first mentioned embodiment.
In a fourth embodiment, our invention is an adhesive comprising the composition of the first mentioned embodiment.
Other embodiments of the invention encompass details about the compounds employed that comprise the claimed composition, the relative amounts thereof, the conditions appropriate for use of the composition, and the properties of the composition, all of which are hereinafter disclosed in the following discussion of each of the facets of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The catalysts included in the composition of the present invention for the cross-link reaction are a phosphine and a Michael acceptor, hence the name co-catalyst. The total amount of co-catalyst on the solid coating composition is preferably about 0.05 to about 20 wt. %, more preferably about 0.1 to about 15 wt. %, most preferably about 0.5 to about 10 wt. %. The co-catalysts are preferably used in a ratio of Michael acceptor groups to phosphine groups of about 0.05:1 to about 20:1, more preferably about 1:6 to about 6:1. The phosphine compound may preferably be used in a range of about 0.05 to about 20 eq. % on isocyanate-reactive groups, more preferably about 0.1 to about 15 eq. %, most preferably about 0.5 to about 10 eq. %. The Michael acceptor compound may be used in a range of about 0.05 to about 20 eq. % on isocyanate-reactive groups, more preferably about 0.1 to about 15 eq. %.
The isocyanates of the present invention comprise at least one isocyanate-functional compound. The isocyanate-functional compound can be an aromatic, aliphatic, cycloaliphatic and/or araliphatic isocyanate-functional compound optionally comprising heteroatoms such as oxygen and groups such as ester groups. The isocyanate-functional compound can also be an isocyanurate, uretdione, biuret, allophanate, an adduct, NCO prepolymers, or mixtures thereof.
Examples of suitable isocyanates to be used as the isocyanate-functional compound, or as starting materials for preparing an isocyanate-functional compound comprising an isocyanurate, biuret or uretdione structure include organic polyisocyanates represented by the formula
R(NCO)
k
wherein k is 2 or higher and R represents an organic group obtained by removing the isocyanate groups from an organic polyisocyanate having aromatically or (cyclo)aliphatically bound isocyanate groups. Preferred diisocyanates are those represented by the above formula wherein k is 2 and R represents a divalent aliphatic hydrocarbon group having 2 to 18 carbon atoms, a divalent cycloaliphatic hydrocarbon group having 5 to 15 carbon atoms, a divalent araliphatic hydrocarbon group having 7 to 15 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms. Examples of organic diisocyanates which are particularly suitable include ethylene diisocyanate, 1,3-propylene diisocyanate 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2-methyl-1,5-diisocyanate pentane, 2-ethyl-1,4-diisocyanate butane, 1,12-dodecamethylene diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate, 1-isocyanato-2-isocyanatomethyl cyclopentane, isophorone diisocyanate, bis-(4-isocyanatocyclohexyl)-methane, 2,4′-dicyclohexylmethane diisocyanate, 1,3- and 1,4-bis(isocyanatomethyl)-cyclohexane, bis-(4-isocyanato-3-methyl-cyclohexyl)-methane, 1-methyl-2,4- and -2 ,6-d ilsocyanato cyclohexane, 1-isocyanato-1-methyl-4(3)-isocyanatomethyl cyclohexane, xylene diisocyanate, &agr;,&agr;,&agr;′,&agr;′-tetramethyl-1,3- and -1,4-xylylene diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-toluylene diisocyanate, 2,4′- and 4,4′-diphenylmethane diisocyanate, 1,5-diisocyanato naphthalene, and mixtures thereof. Aliphatic polyisocyanates containing 3 or more isocyanate groups such as 4-isocyanatomethyl-1,8-octane diisocyanate and lysine triisocyanate, and aromatic polyisocyanates containing 3 or more isocyanate groups such as 4,4′,4″-triphenylmethane triisocyanate, 1,3,5-triisocyanate benzene, polyphenyl polymethylene polyisocyanates obtained by phosgenating aniline/formaldehyde condensates, and mixtures thereof may also be used.
Examples of suitable polyisocyanates comprising an allophanate structure is include the above-mentioned organic polyisocyanates reacted with a mono- or polyalcohol.
Suitable mono- or polyalcohols which may be used to prepare the polyisocyanates containing allophanate groups include aliphatic, cycloaliphatic, araliphatic or aromatic mono- or polyalcohols. The mono- or polyalcohols may be linear, branched or cyclic, contain at least one carbon atom and have a molecular weight of up to 2500. The mono- or polyalcohols may optionally contain other hetero atoms in the form of, e.g., ether groups, ester groups, etc. However, the mono- or polyalcohols preferably do not contain hetero atoms other than the hydroxyl group(s). The molar ratio of mono- or polyalcohol to polyisocyanate is about 0.01 to about 0.5, preferably about 0.04 to about 0.2. Preferred mono- or polyalcohols are hydrocarbon mono- or polyalcohols and mono- or polyalcohols containing ether groups. The hydrocarbon mono- or polyalcohols preferably contain 1 to 36, more preferably 1 to 20, and most prefera
Hulsbos Edith
M. Van Dijk Joseph Theodorus
Akzo Nobel N.V.
McGillycuddy Joan M.
Sergent Rabon
LandOfFree
Compositions comprising an isocyanate-functional compound,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compositions comprising an isocyanate-functional compound,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compositions comprising an isocyanate-functional compound,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3146588