Organic compounds -- part of the class 532-570 series – Organic compounds – Four or more ring nitrogens in the bicyclo ring system
Reexamination Certificate
1994-10-18
2002-09-10
Gupta, Yogendra N. (Department: 1751)
Organic compounds -- part of the class 532-570 series
Organic compounds
Four or more ring nitrogens in the bicyclo ring system
C544S194000, C544S196000, C544S200000, C544S204000, C544S207000, C544S212000
Reexamination Certificate
active
06448398
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the preparation of acid amides by reacting (Si, Ge or Sn substituted amino)-1,3,5-triazines, such as (N-silylated amino)-1,3,5-triazines, with acid halides.
2. Description of Related Art
Various derivatives of amino-1,3,5-triazines are described in the literature for use in a wide variety of fields. Certain of these derivatives, such as alkoxymethyl derivatives of melamine and guanamines, are useful as crosslinkers or reactive modifiers in curable compositions which contain resins having active hydrogen groups. While alkoxymethylated melamines and guanamines provide excellent results in a number of aspects, they also have the disadvantage of releasing formaldehyde as a volatile by-product under curing conditions. It has long been a desire of industry to find acceptable alternatives which do not emit formaldehyde upon cure.
One such alternative which has shown great promise is carbamate and isocyanate functional 1,3,5-triazines disclosed in U.S. Pat. Nos. 4,939,213, 5,084,541, 5,288,865, U.S. application Ser. No. 07/998,313 (filed Dec. 29, 1992), U.S. application Ser. No. 08/061,905 (filed May 13, 1993), U.S. application Ser. No. 08/138,581 (filed Oct. 15, 1993), U.S. application Ser. No. 08/239,009 (filed May 6, 1994), and U.S. application Ser. No. 08/286,835 (filed Aug. 5, 1994), all of which are commonly owned with the present application and all of which are hereby incorporated by reference herein as if fully set forth. The carbamate and isocyanate functional 1,3,5-triazines disclosed in these references have been found to be particularly useful as crosslinkers in coating compositions based upon hydroxy functional resins, with the cured coatings possessing a wide range of desirable properties.
The ability of carbamate and isocyanate functional 1,3,5-triazines to perform as efficient non-formaldehyde emitting crosslinking agents, particularly in curable coating compositions, has initiated intensive research directed towards the discovery of practical and economical processes for their production, a number of which are disclosed in the previously incorporated references. While a number of these processes have shown great promise, certain of them also have some drawbacks including, for example, the required use of expensive starting materials and/or low ultimate yield of the desired products.
In addition to the processes of the aforementioned incorporated references, it has now been surprisingly discovered that acid amides can be prepared with excellent yields by reacting (Si, Ge or Sn substituted amino)-1,3,5-triazines, such as silylated melamine, with acid halides. It has also been discovered that the use of a acid halide selected from the group consisting of oxalyl chloride, phosgene or phosgene analogs provides excellent yields of isocyanate-functional 1,3,5-triazines. The isocyanate-functional 1,3,5-triazines may be further derivatized by contacting the same with a wide variety of well-known isocyanate-reactive materials. For example, these isocyanates may be readily “blocked” (for example, converted to the corresponding carbamate) by adding a blocking agent (such as a hydroxyl compound) to the isocyanate-functional 1,3,5-triazine without isolating it. In addition, the isocyanates may be readily oligomerized by adding a multifunctional isocyanate-reactive compound (for example, a diol or diamine) to the isocyanate-functional 1,3,5-triazine without isolating it.
It should be noted that it is generically known to obtain isocyanates by phosgenation of silylated amines as disclosed in Mironov et al., Zh. Obshchei. Khim. 1969, 39(11), 2598-9 and Chem. Abstracts No. 66300r, Vol.72, 1970, p.328. It is, however, also well known that the amine functionality of amino-1,3,5-triazines, such as melamine, is not equivalent to other types of typical amine functionality. Significantly, melamines are among the least reactive of the “amines” and the most difficult to functionalize, and their behavior cannot normally be correlated to that of other known amines.
For example, most “typical” amines are highly reactive with acid halides. In a publication by E. M. Smolin and L. Rappaport entitled “S-Triazines and Derivatives,” Interscience Publishers Inc., New York, page 333 (1959), it is reported that attempts to react an acid halide with the amino group on a 1,3,5-triazine such as melamine were not successful. Further, attempts to functionalize amino-1,3,5-triazine often results in substitution at the nitrogen on the triazine ring. For example, it is known that the reaction of melamine with alkyl halides, such as allyl chloride, results in alkyl substitution at the nitrogen on the triazine ring resulting in isomelamine derivatives.
Indeed, it is reported in U.S. Pat. No. 3,732,223 that the well-known phosgenation of amines fails to produce isocyanate functionality when applied to amino-1,3,5-triazines. In subsequent U.S. Pat. No. 3,919,221, the phosgenation of amino-1,3,5-triazines having one or two unsubstituted amino groups attached to the triazine ring to obtain monoisocyanato and diisocyanato triazines is reported to occur under certain specified conditions. These references do not, however, suggest that (Si, Ge or Sn substituted amino)-1,3,5-triazines can be reacted with acid halides, such as phosgene, to produce acid amides, and particularly isocyanate-functional 1,3,5-triazines, in significant yields.
Surprisingly, a procedure has now been discovered in which acid halides, including phosgene (and phosgene sources) and halogenated formates, can readily and effectively be reacted with (Si, Ge or Sn substituted amino)-1,3,5-triazines to produce a corresponding acid amide, including isocyanate- and carbamate-functional 1,3,5-triazines. Moreover, the isocyanate-functional derivatives can further be readily and effectively reacted with known isocyanate-reactive materials (such as blocking agents) to produce the corresponding isocyanate-based derivatives thereof.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a process for preparing acid amides which, in its overall concept, comprises the step of contacting:
(a) a (Si, Ge or Sn substituted amino)-1,3,5-triazine represented by the formula:
wherein
wherein Z and Z
1
are independently selected from the group consisting of hydrogen, a hydrocarbyl, a hydrocarbyloxy, a hydrocarbylthio, a group represented by the formula —N(Q)
2
, and a group represented by the formula:
each Q is independently selected from the group consisting of hydrogen, hydrocarbyl, hydrocarbyloxy hydrocarbyl and M(R
1
)
3
, provided that at least one Q group is M(R
1
)
3
,
A is an n-functional anchor,
n is at least 2,
each Z
2
is independently selected from the group consisting of hydrogen, a hydrocarbyl, a hydrocarbyloxy, a hydrocarbylthio and a group represented by the formula N(Q)
2
,
each M is independently selected from the group consisting of silicon, germanium and tin, and
each R
1
is independently selected from substituted or unsubstituted alkyl, alkenyl, aryl, aralkyl and alkoxy groups; and
(b) an acid halide,
under reaction conditions sufficient to produce a corresponding acid amide derivative.
As indicated above, an acid amide is produced by contacting an acid halide with the (Si, Ge or Sn substituted amino)-1,3,5-triazine. An isocyanate-functional 1,3,5-triazine is produced by employing, for example, phosgene, oxalyl chloride or a phosgene analog as the acid halide. This isocyanate-functional 1,3,5-triazine may be reacted with isocyanate-reactive materials to produce various isocyanate-based derivatives. For example, the isocyanate groups may be blocked by contacting the isocyanate-functional 1,3,5-triazines with known isocyanate blocking agents, such as certain active hydrogen containing compounds. As another example, oligomers of the isocyanate-functional 1,3,5-triazines can be produced by contacting the same with multifunctional isocyanate-reactive materials such as diols and diamines. The phrase “isocyanate and/or isocyanate-based” 1,3
Cytec Technology Corp.
Didamo Valerie T.
Gupta Yogendra N.
Jubinsky James A.
Schultz Claire M.
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