Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1990-09-14
1995-05-02
Foelak, Morton
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
528143, 528150, 528165, C08G 804
Patent
active
054120586
DESCRIPTION:
BRIEF SUMMARY
I. TECHNICAL FIELD
The present invention pertains to phenolic novolak resins obtained by condensation with heavy aliphatic aldehydes, a procedure for their synthesis and their application to the reinforcement of rubber.
The phenolic resins, which are condensation products of phenols and aldehydes, have been known for more than 75 years (Baekeland, 1907, compositions of moldable products). They are categorized into two groups: products obtained with an aldehyde: phenol ratio greater than 1 and under basic catalysis conditions; products obtained with an aldehyde: phenol ratio lower than 1 and under conditions of acid catalysis. These novolaks can then be cross-linked under the effect of formaldehyde donors, i.e., hexamethylenetetramine or resins, such as phenolic resins or more or less etherified melamine resins.
II. PRIOR TECHNIQUE
The novolaks have had noteworthy industrial applications for a long time, e.g., as powders for molding and as binding resins for brake fittings. They provide particular value in the reinforcement of rubbers where it is necessary to make pieces which must resist abrasion or deformation, e.g., tire treads or beads, window washers, conveyor belt rollers, printing rollers.
The aldehyde which is by far the most widely used for the synthesis of novolaks is formaldehyde or one of its precursors, paraformaldehyde, trioxane or hexamethylenetetramine. Aliphatic dehydes are also employed to a lesser extent. Thus, the use of acetaldehyde or paraldehyde (a polymer of acetaldehyde) is described in German Patent DP 365,286 (Farbwerk vorm. Meister Lucius & Bruining, 1920), in U.S. Pat. No. 1,370,666 (E. E. Novotny, 1921) and U.S. Pat. No. 1,598,546 (Bakelite Corp., 1926). In U.S. Pat. No. 2,176,951 (Resinox Corp., 1937), which claims the synthesis of phenol/butyraldehyde resins with basic catalysts, the example is given with a phenol:butyraldehyde ratio of 1:0.7. U.S. Pat. No. 2,231,860 (Monsanto, 1941 ) describes mixed phenol/butyraldehyde/formaldehyde resins obtained by condensation in two stages: condensation of the phenol with butyraldehyde with acid or basic catalysts, then condensation with formaldehyde in an acid medium. In European Patent EP 19,151 (BASF, 1980) are described phenol/isobutyraldehyde resins intended for the manufacture of flexographic printing inks, created with isobutyraldehyde: phenol molar ratios apparently greater than 1. However, reading shows (see page 3, lines 1 to 3 of the French translation of this patent) that although these novolak resins are indeed prepared with isobutyraldehyde: phenol molar ratios between 1.2:1 and 1.3:1, their true molar ratio after reaction is in fact less than 1. The excess of isobutraldehyde is probably caught up in low-molecular weight condensates, the elimination of which by steam distillation constitutes the improvement claimed in European Patent Application EP 50,230 (BASF, 1981). We can also find in French Patent Application 2,132,359 (Uniroyal, 1982), the description of resorcin/alkyl aldehyde novolaks with 1 to 4 carbons, and their claim for use in the adhesion of rubber to textile cables.
III. PRESENTATION OF THE INVENTION
The Applicant discovered that, surprisingly, the novolak resins obtained by condensation of phenols and heavy aldehydes (i.e., with a number of carbons equal to or greater than 6) had structures different from the structures of novolak resins based on formaldehyde, that they could be obtained with aldehyde: phenol molar ratios greater than 1, and with yields close to the theoretical. This teaching is not found in the prior state of the art, and although the patents which cite heavy-aldehyde novolaks, such as, e.g., U.S. Pat. No. 2,173,346 (Bakelite Corp, 1935), GB Patent 790,644 (Esso Research) or U.S. Pat. No. 2,131,249 (Balle), embody reactive masses in which the aldehydes: phenols ramos are close to unity, they lead only to novolaks with the same stoichiometry as the known novolaks because of their relatively low yields.
With structures of the type [.PHI.CH(R.sub.n-1)].sub.p -.PHI. which are normally a
REFERENCES:
patent: 2131249 (1938-09-01), Balle
Dreyfus Thierry
Le Bourt Noel
CECA S.A.
Dodson Shelley A.
Foelak Morton
Sigalos John L.
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