Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2001-03-23
2003-03-11
Sellers, Robert E. L. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C525S504000, C525S523000, C528S150000, C528S162000
Reexamination Certificate
active
06531567
ABSTRACT:
The present invention relates to Mannich bases prepared using alkyldipropylenetriamines and to addition compounds (adducts) of alkyldipropylenetriamines with acrylonitrile and ethylene oxide or propylene oxide, to the products obtained therefrom by the further addition of epoxy compounds having on average at least one epoxy group per molecule, and to the use of such products as hardeners for epoxy resins and finally to a method of producing cured products using such curable compositions.
Curable compositions based on amine curing agents and epoxy resins are used widely in industry to coat and treat metal and mineral substrates. There are used as amine curing agents especially aliphatic, cycloaliphatic or aromatic amines as well as polyaminoamides which may or may not contain imidazoline groups.
The mechanical and physical properties of the curable compositions based on those amines are sufficient for many applications.
In the field of coatings in particular, however, there is a demand for binder systems that are surface-tolerant, that is to say that exhibit good adhesion even to substrates that are difficult to coat, such as, for example, damp substrates or sheet metal that has not been pretreated, and that provide optimum protection of the substrate, for example protection against corrosion. There is also a demand for rapid onset of curing of the binder systems after application to the substrates also at low temperatures, for example in order to provide rapid loading capability or to enable overcoating.
For external applications in particular, a high degree of early water resistance of the as yet uncured film (e.g. by droplet formation at high relative atmospheric humidity) is an important criterion, as is low viscosity of the binder so that the binder can still be processed even at low temperatures. Low temperatures are understood to be temperatures of generally less than 15° C. Highly viscous Mannich bases based on polyamines and alkylphenols are therefore poorly suited to such external applications. Moreover, they have a high colour number and in many cases exhibit unsatisfactory adhesion to the substrates described hereinbefore and poor adhesion to subsequently applied surface-coatings.
As hardeners for epoxy resins that have relatively good corrosion protection and useful adhesion even to difficult substrates there are known polyaminoamides that generally contain imidazoline groups. Such compounds are prepared by condensation of generally unsaturated, long-chain fatty acids with polyethylenepolyamines. The disadvantage of such compounds is their high viscosity at low temperatures (less than 15° C.) and the slow rate of onset of cure and full cure. Such compounds also have relatively high colour numbers.
The problem of the present invention was accordingly to overcome those disadvantages.
The problem was solved by the provision of the alkyldipropylenetriamine-based compounds according to the invention and their adducts with epoxy compounds that contain on average at least one epoxy group per molecule.
Surprisingly it has been found that although, in their structure, the alkyidipropylenetriamine-based compounds according to the invention are similar to polyaminoamides which may or may not contain imidazoline, they have a markedly higher rate of onset of cure and full cure, especially at low temperatures of less than 15° C. Moreover, such compounds have in comparison significantly lower viscosity and colour number.
The invention relates to products comprising one or more compound(s) of formula (I)
wherein R
1
is a hydrocarbon radical having from 8 to 22, preferably from 12 to 22, carbon atoms, and from 50 to 90 per cent of the R
2
radicals of the product denote a hydrogen atom and the remaining R
2
radicals of the product denote a group selected from
a) a radical of formula
wherein R
a
and R
b
are each independently of the other a hydrogen atom or an aliphatic, cycloaliphatic, aromatic or araliphatic radical having from 1 to 22, preferably from 1 to 12, carbon atoms,
b) a radical of formula —CH
2
—CH(R
c
)—OH, wherein R
c
is —H or —CH
3
, and
c) a radical of formula —CH
2
—CH
2
—CN.
The products accordingly comprise overall a composition of discrete compounds of formula 1, which may in theory have 0, 1, 2, 3 or 4 amine hydrogen atoms, the compounds having, however, as a statistical average over the total amount, from 50 to 90% amine hydrogen atoms.
Preference is given to products comprising more than one compound of formula (I), wherein from 60 to 85 per cent, preferably from 65 to 80 per cent, of the R
2
radicals of the product denote a hydrogen atom.
Preference is also given to products in the form of a compound of formula (I), wherein two or three, preferably three, of the R
2
radicals of the product denote a hydrogen atom.
As starting materials for the preparation of the products of general formula (I) according to the invention there are used alkyldipropylenetriamines of general formula (II)
wherein R is a hydrocarbon radical having from 8 to 22, preferably from 12 to 22, carbon atoms.
The compounds of formula (II) are customarily prepared by cyanoethylation of amines (fatty amines) and subsequent hydrogenation according to processes known per se.
In those processes the amines or fatty amines are reacted with acrylonitrile, and then the cyanide groups are hydrogenated in the presence of a catalyst. The reaction sequence can be shown schematically as follows:
The so-called fatty amines preferably used as starting materials for the cyanoethylation are mixtures of long-chain primary alkylamines, obtained from mixed glycerol esters of medium and higher fatty acids having an even number of carbon atoms, as occur in plant and animal substances. For example, beef tallow contains almost 100% (esterified) fatty acids having a carbon chain length of 14, 16 and 18 carbon atoms. The beef tallow fatty amines obtained from beef tallow are commercially available as tallow fatty amine, e.g. Genamin® TA100 (Clariant). Accordingly, if fatty amines of natural products are used as starting materials in the preparation of amines according to formula (II), the products of general formula (II) comprise mixtures of compounds of different chain length R. The chains R have about from 8 to 20 carbon atoms, with a maximum of about 22 carbon atoms, and may either be saturated or have multiple bonds and may be either straight-chain or branched. Further examples of commercially available fatty amines that can be used according to the invention, in addition to tallow fatty amine, are saturated, straight-chain fatty amines, such as dodecylamine and tetradecylamine, saturated branched fatty amines, such as isotridecylamine, unsaturated and saturated fatty amines and fatty amine mixtures, such as coconut fatty amine, oleylamine, rape oil fatty amine and stearylamine.
The products of formula (I) wherein some of the R
2
radicals of the product denote hydrogen atoms and the remaining R
2
radicals of the product denote a radical of formula
wherein R
a
and R
b
are each independently of the other a hydrogen atom or an aliphatic, cycloaliphatic, aromatic or araliphatic radical having from 1 to 22, preferably from 1 to 12, carbon atoms, are so-called Mannich bases. They are prepared in a manner known per se, for example by taking a compound of formula (II) and then adding a phenol derivative and dissolving it at elevated temperature. In the next step, paraformaldehyde in the form of granules is so added in portions that the temperature of the exothermic reaction does not exceed 100° C. Once the addition is complete, the reaction mixture is gradually heated to 150° C. over the course of one hour, with the reaction water that is formed being distilled off. The success and completion of the reaction can be monitored easily by reference to the amount of water collected. Other possible preparation methods include the complete or partial reaction of the phenol derivative with an aldehyde before adding the amine; also, first the reaction of amine and aldehyde before adding the phenol derivative; and
Scherzer Wolfgang
Volle Jörg
Esq. Kristin Neuman
Proskauer Rose LLP
Sellers Robert E. L.
Vantico GmbH & Co.
LandOfFree
Mannich bases and further compounds based on... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mannich bases and further compounds based on..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mannich bases and further compounds based on... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3021165