Polymer-carbon black mixing
AssigneePolysar Limited
InventorsGeorge J. Briggs, Yung-Kang Wei
Life of this patent
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Abstract
A process is provided for the production of vulcanizates having improved properties wherein polymer (or polymers) is mixed with carbon black in two separate steps such that in one step a major proportion of the carbon black to be used is mixed with polymer and in a second step a zero to minor proportion of the carbon black to be used is mixed with polymer. Such improved vulcanizates may be used, for example, in tires or a variety of mechanical goods.
Claims16
A process for producing a vulcanizate having improved properties, said process comprising the steps of:
- (a) mixing in at least two separate steps two or more C.sub.4 or C.sub.5 conjugated diolefin containing polymers with carbon black and other compounding ingredients except cure active agents, followed by resting of the compounds so produced,
- (b) mixing the compounds from (a) with other compounding ingredients including sulphur and sulphur-containing or peroxidic cure active agents,
- (c) shaping the mixture from (b), and
- (d) vulcanizing the shaped mixture by heating at a temperature of from about 145.degree. C. to about 225.degree. C. for a time of from about 3 to about 60 minutes,
- characterized in that in step (a), the polymers are mixed in at least two separate steps wherein:
- (i) about 33 to about 60 weight percent of one or more of the polymers is mixed with from about 60 to 100 weight percent of the carbon black and with other compounding ingredients except cure active agents, said polymers being selected from C.sub.4 or C.sub.5 conjugated diolefin containing synthetic polymers,
- (ii) about 67 to about 40 weight percent of one or more of the polymers is mixed with from 0 to about 40 weight percent of the carbon black and with other compounding ingredients except cure active agents, said polymers being selected from C.sub.4 or C.sub.5 conjugated diolefin containing synthetic polymers and natural rubber, such mixing of polymers, carbon black and other compounding ingredients being in a single mix or in separate mixes containing only a single polymer,
- (iii) the compounds from (i) and (ii) are supplied to step (b).
A process for producing a vulcanizate having improved properties, said process comprising the steps of:
- (a) mixing in two separate steps one or two C.sub.4 to C.sub.5 conjugated diolefin containing polymers with carbon black and other compounding ingredients except cure active agents, followed by resting of the compounds so produced,
- (b) mixing the compounds from (a) with other compounding ingredients, including sulphur and sulphur-containing or peroxidic cure active agents,
- (c) shaping the mixture from (b), and
- (d) vulcanizing the shaped mixture by heating at a temperature of from about 145.degree. to about 225.degree. C. for a time of from about 3 to about 60 minutes,
- characterized in that in step (a) the polymer or polymers are mixed in two separate steps wherein:
- (i) about 40 to about 60 weight percent of the polymer or polymers selected from C.sub.4 or C.sub.5 conjugated diolefin containing synthetic polymers is mixed with from about 60 to 100 weight percent of the carbon black and with other compounding ingredients except cure active agents,
- (ii) about 60 to about 40 weight percent of the polymer or polymers selected from C.sub.4 or C.sub.5 conjugated diolefin containing synthetic polymers and natural rubber is mixed with from 0 to about 40 weight percent of the carbon black and with other compounding ingredients except cure active agents, and
- (iii) the compounds from (i) and (ii) are supplied to step (b).
Dependencies are inferred from the claim text.