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...
Patent
1986-02-21
1988-08-09
Anderson, Harold D.
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...
528 52, 528 53, 528 73, C08G 1808, C08G 1820, C08G 1828, C08G 1877
Patent
active
047629002
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a method of curing a thermosetting resin composition into an oxazolidone polymer.
Oxazolidone polymers are well known in the art. They are usually prepared by reacting an isocyanate or isothiocyanate with a vicinal epoxide in the presence of a catalyst. The catalysts which have been used in the past include alkali metal halides, tertiary amines, and quaternary ammonium halides (eg tetraethyl ammonium bromide) as described in, for example, U.S. Pat. No. 3,020,262. More recently, catalysts consisting of phosphonium salts (U.S. Pat. No. 3,687,897) and magnesium halide/phosphine oxide complexes (U.S. Pat. No. 3,905,945) have been employed.
Many of the catalysts which have previously been employed have not favoured the production of the preferred oxazolidone structure over the production of the isocyanurate/isothiocyanurate structure in the resulting polymer, and in certain cases have catalysed the production of polymers containing hydrophilic groupings which are undesirable in the formation of polymers required to be water resistant.
It has previously been shown that the oxazolidone content of a poly(oxazolidone/isocyanurate) polymer may be increased by increasing the molar proportion of isocyanate in the starting composition used to produce the polymer. However, this leads to an increase in the brittleness of the polymer produced. The molar ratio of epoxy:isocyanate in the starting composition is preferably kept reasonably close to unity in order to avoid an increase in brittleness.
It is an object of the present invention to provide a method of preparing an oxazolidone polymer in the presence of a catalyst which favours the formation of an oxazolidone rather than an isocyanurate structure in the resulting polymer.
Accordingly, the present invention provides a method of preparing an oxazolidone polymer which comprises reacting a vicinal polyepoxide having a functionality greater than 1 with an organic polyisocyanate or polyisothiocyanate, in the presence of a catalyst comprising an aliphatic s-triazine compound or an aliphatic derivative thereof, at a temperature between 20.degree. C. and 250.degree. C.
The vicinal polyepoxide compound and the polyisocyanate or polyisothiocyanate compound may be any suitable compounds which are known to react together to give an oxazolidone polymeric structure.
Preferred polyepoxides include compounds containing a di- or poly-glycidyl grouping. For example, they include polyglycidyl ethers of polyhydric alcohols, such as Bisphenol A. They may also be polyglycidyl ethers of ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 2,4,6-hexanetriol, glycerol and trimethylolpropane.
Polyglycidyl esters of polycarboxylic acids such as oxalic acid, succinic acid, gluataric acid, adipic acid, azelaic acid, phthalic acid, isophthalic acid, terephathalic acid, 2,5-naphthalene dicarboxylic acid and dimerised linolenic acid may be employed as the polyepoxide. Examples include diglycidyl adipate and diglycidyl phthalate.
Other examples include polyepoxides derived from the epoxidation of olefinically unsaturated aliphatic compounds, polyepoxides of organic amines, eg a tetraglycidyl substitued 4,4'-diaminodiphenyl-methane, and dialicyclic compounds of the general formula: ##STR1## where L is a simple linkage group such as CH.sub.2, CH.sub.2 O, CO, COO, CH.sub.2 CH.sub.2, CH.sub.2 OCH.sub.2, CH.sub.2 CO, CH.sub.2 OCO and CH.sub.2 COO.
Although the polyepoxide preferably does not contain high concentrations of secondary groups which react with isocyanates or isothiocyanates, (eg hydroxy groups), the polyepoxide may be selected from prepolymers which contain terminal epoxy and secondary, non-terminal hydroxy groups, as described in U.S. Pat. No. 4,386,191, for example.
Suitable organic poly-isocyanate or poly-isothiocyanate compounds are the aliphatic and aromatic isocyanates including, for example, toluene-2,4-diiso-cyanate; 1,5-naphthalenediisocyanate; cumene-2,4-diisocyanate; 4-methoxy-1,3-phenylenediisocyanate; 4-chloro-1,3-phenylenediisocy
REFERENCES:
patent: 3673128 (1972-06-01), Hayash et al.
patent: 3745133 (1973-07-01), Communale et al.
patent: 4022721 (1977-05-01), Ashida
patent: 4070416 (1978-01-01), Narahara et al.
patent: 4129554 (1978-12-01), Karasawa et al.
patent: 4129695 (1978-12-01), Bonin
patent: 4163815 (1979-08-01), Cheung
patent: 4542165 (1985-09-01), Kumata et al.
Hodd Kenneth A.
Velasco Miguel U.
Anderson Harold D.
Daley Dennis R.
National Research Development Corporation
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