Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-06-29
2002-02-12
Sellers, Robert E. L. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S423000, C525S444000, C528S297000
Reexamination Certificate
active
06346582
ABSTRACT:
The present invention relates to low viscosity compositions of epoxy functional polyester resins, to the use of said compositions for coating applications and non-coating applications, and to processes for the preparation of said compositions.
Several types of polyglycidylester resins, obtainable by glycidating carboxyl functional polyester resin precursors and coating compositions comprising them are known from e.g. EP-A-447360, WO 96/11238, EP-A-0634434, EP-A-0720997.
In these publications carboxyl functional polyesters, derived from specific polycarboxylic acids and polyhydroxy group containing compounds, and their glycidated derivatives, were used in combination with each other or with other structurally different epoxy resins or polyesters respectively in coating compositions, and more in particular powder coating compositions.
Although the linear polyfunctional aliphatic carboxyl polyester resins and the corresponding polyglycidylesters derived therefrom, provided progress towards the modern requirements of outdoor durability (UV stability) and resistance against hydrolysis of the final coating compositions in the cured state, there still exists a need for further improvement of the properties of the coating compositions.
Moreover there has been a growing need for compositions comprising polyglycidylesters that show on the one hand a sufficient epoxy functionality to enable a quick and efficient curing reaction (which may take place in a temperature range from 10 to 260° C. dependent on the specific type of curing agent) and on the other hand a sufficiently low viscosity to enable a fast processability into end use applications, with minimal and preferably no emissions of solvent, and with no emission of toxic reaction products.
Therefore, it is desirable to provide compositions comprising at least one polyglycidylester prepared from carboxyl functional polyesters, is which have the combination of relatively high epoxy functionality and sufficiently low viscosity that provide attractive outdoor durable properties in the final compositions.
It is further desirable to obtain an end-use application composition of such composition which can be cured at temperatures in the range of from 10 to 260° C.
Accordingly, a composition is provided prepared by glycidation of at least one (a) carboxy polyfunctional polyester and at least one (b) &agr;, &agr;-branched monocarboxylic acid containing a tertiary carbon atom and from 5 to 20 carbon atoms and preferably from 5 to 12 carbon atoms, or a glycidyl ester thereof. In general said compositions have an EGC from 2000 to 4000.
Preferred compositions will have an EGC in the range from 3000 to 4000.
More preferably, components (b) are used, containing a tertiary carbon atom and containing from 5 to 10 carbon atoms. Most preferably VERSATIC acids (VERSATIC is a trademark) from Shell Chemical Company or CARDURA glycidyl esters (of VERSATIC acids) from Shell Chemical Company are used (CARDURA is a trademark).
The weight ratio between carboxyl polyfunctional polyester or polyglycidyl ester thereof (a) and &agr;,&agr;-branched monocarboxylic acid or glycidyl ester thereof (b) may vary in the range from 19:1 to 1:1 and preferably from 6:1 to 2:1.
It will be appreciated that the compositions according to the present invention can be prepared from starting mixtures comprising component (a) as such or from starting mixtures comprising the constituents of the carboxy polyfunctional polyester to be formed in an initial step.
In general, the compositions of the present invention can be prepared according to a process as follows:
I. mixing the constituents of the carboxy polyfunctional polyester to be formed (a) and the &agr;, &agr;-branched monocarboxylic acid as specified hereinbefore (b) and preparing the desired carboxy polyfunctional polyester by known esterification methods, preferably by azeotropic condensation, at temperatures in the range of from 100 to 220° C. and preferably from 160 to 220° C., during a period of from 2 to 8 hours, followed by glycidation of the mixture obtained with epihalohydrin and preferably epichlorohydrin.
II. mixing the constituents of the carboxy poly-functional polyester to be formed (a) and preparing the desired carboxy functional polyesters, as specified under I, addition of the &agr;, &agr;-branched monocarboxylic acid to obtained polyester, followed by glycidation of the mixture.
III. mixing the constituents of the carboxy polyfunctional polyester to be formed (a) and preparing said desired carboxy polyfunctional polyester, as specified hereinbefore, and glycidation of said obtained polyester with a mixture of epihalohydrin and the glycidyl ester of &agr;, &agr;-branched monocarboxylic acid.
IV. mixing the constituents of the carboxy polyfunctional polyester to be formed (a) and preparing the desired carboxy polyfunctional polyester, as specified hereinbefore, and glycidation with epihalohydrin to obtain the corresponding polyglycidyl ester, and dilution of the polyglycidyl ester with the glycidyl ester of &agr;, &agr;-branched monocarboxylic acid.
The compositions so obtained surprisingly have been found to show a combination of a sufficiently high epoxy functionality (Ep Fav 1.5-3.5) necessary for a fast curing into outdoor durable (coating) layers or formed products, and an attractive low viscosity (in the range of from 1-15 Pa.s and preferably from 1 to 10 Pa.s), enabling in addition a fast processing.
These results could certainly not be predicted or even expected by an average person skilled in the art, in view of Technical Bulletin, Shell Chemicals, CM 5.1, July 1996, actually disclosing only blends of bifunctional epoxy resins and CARDURA glycidyl esters, having a decreased epoxy functionality below 2, and showing poor outdoor durable properties.
As component (a) in the compositions of the present invention, a great variety of linear or branched carboxy polyfunctional polyesters, can be used.
More in particular suitable starting carboxy polyfunctional polyesters can be prepared by reaction of:
(i) at least one aromatic, aliphatic or cycloaliphatic dicarboxylic acid, and preferably aliphatic or cycloaliphatic dicarboxylic acid (B), and
(ii) at least one dihydroxymonocarboxylic acid compound (C), comprising a tertiary aliphatic carboxyl group and two aliphatic hydroxyl groups, which may each independently be primary or secondary hydroxyl, and
(iii) optionally one diol compound (D) comprising two aliphatic hydroxyl groups which may each independently be a primary or a secondary hydroxyl group, and
(iv) optionally an alcohol compound (A′) comprising one monofunctional primary or secondary hydroxyl group and/or an alcohol compound (A″), comprising one primary or secondary hydroxyl group and one tertiary aliphatic carboxyl group, and
(v) optionally a trifunctional hydroxy compound (E), comprising three aliphatic hydroxyl groups which may each independently be a primary or secondary hydroxyl group,
(vi) optionally a tetrafunctional hydroxy compound (F), comprising four aliphatic hydroxyl groups, which may each independently be a primary or a secondary hydroxyl group,
the molar ratio of compound A′:A″:B:C:D:E:F being M:N:X+Y+2P+3Q+1:X:Y:P:Q
wherein M+N=0-4
Y ranges from 0 to 5,
X ranges from 1 to 8,
P ranges from 0 to 2, and
Q ranges from 0 to 1 at a temperature within the range of from 100 to 220° C. and preferably from 160 to 220° C., during a period of from 2 to 8 hours and preferably from 6 to 8 hours.
The reaction is continued until essentially all the hydroxyl groups initially present in the reaction mixture have been esterified.
For the preparation of the starting carboxy polyfunctional polyesters, a condensation reaction is carried out after charging all constituents A to F, and optionally a (non reacting or only slowly reacting) VERSATIC acid component, simultaneously to the reactor, whereafter the temperature is increased to a temperature in the range of from 100 to 220° C. This temperature is maintained over a period of from 2 to 8 hours, thus
Kooijmans Petrus Gerardus
Vos Eric Johannes
Watkins Michael James
LandOfFree
Glycidation of carboxy polyester and tertiary C... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Glycidation of carboxy polyester and tertiary C..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Glycidation of carboxy polyester and tertiary C... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2966338