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US 10,858,481 B2Granted
Process for suppressing foam formation in the manufacture of hydrophilic polyamides
AssigneeInvista North America S.A.R.L.
InventorCharles Richard Langrick
Life of this patent
Estimating the term…
Abstract
Disclosed is a process for making a polyetheramine containing polyamide without excessive foaming in successive batches by providing a controlled heat input rate step for those batch runs that incorporate polyetheramine containing polyamide heel from previous runs.
Claims20
A process for making polyamide comprising:
- (a) at least partially polymerizing a first aqueous charge of a diamine and a diacid to form polyamide in a reactor;
- (b) adding a polyetheramine to the reactor and further polymerizing the diamine, diacid and polyetheramine to form polyetheramine-containing polyamide in the reactor;
- (c) recovering a first portion of the polyetheramine-containing polyamide from the reactor and retaining a second portion of the polyetheramine-containing polyamide within the reactor;
- (d) loading the reactor with a second aqueous charge of diamine and diacid and at least partially polymerizing the second aqueous charge with the second portion of the polyetheramine-containing polyamide within the reactor;
- (e) heating the reactor at heat input rate Q1 to temperature range T1 and pressure range P1;
- (f) reducing the heat input rate to Q2 and holding the reactor at temperature range T2 and pressure range P2 for about 1 minute to about 40 minutes to reduce the water content of the polymerizing mass;
- (g) adding polyetheramine to the reactor;
- and
- (h) increasing the heat input rate to the reactor to Q3, where Q3 >Q2, and at least partially venting the reactor to control pressure at or below range P1, and further polymerizing to form polyetheramine-containing polyamide within the reactor.
6 more elements
A process for making polyamide comprising:
- a. charging diamine and diacid to the feed inlet of a continuous plug flow reactor under reaction conditions to at least partially form polyamide;
- b. downstream of the feed inlet, adding a first stream of polyetheramine to the continuous plug flow reactor and further polymerizing the diamine, diacid and polyetheramine to form polyetheramine-containing polyamide in the continuous plug flow reactor;
- c. recovering a first portion of the polyetheramine-containing polyamide from the outlet of the continuous plug flow reactor and recycling a second portion of the polyetheramine-containing polyamide to a recycle charge point downstream of the feed inlet;
- d. providing a primary polymerization section of the continuous plug flow reactor at heat input rate Q1 to temperature range T1 and pressure range P1;
- e. providing a secondary polymerization section downstream of the primary polymerization section of the continuous plug flow reactor, at heat input rate to Q2 and at temperature range T2 and pressure range P2 for about 1 minute to about 40 minutes to reduce the water content of the polymerizing mass;
- f. adding a second stream of polyetheramine to the continuous plug-flow reactor downstream of the secondary polymerization section;
- and
- g. providing a tertiary polymerization zone with heat input rate Q3, where Q3 >Q2, and at least partially venting the continuous plug flow reactor to control pressure at or below range P1 to form polyetheramine-containing polyamide within the continuous plug flow reactor.
5 more elements
A process for making polyamide comprising:
- a. at least partially polymerizing a first aqueous charge of polyamide precursor to form polyamide in a reactor;
- b. adding a polyetheramine to the reactor and further polymerizing the polyamide precursor and polyetheramine to form polyetheramine-containing polyamide in the reactor;
- c. recovering a first portion of the polyetheramine-containing polyamide from the reactor and retaining a second portion of the polyetheramine-containing polyamide within the reactor;
- d. loading the reactor with a second aqueous charge of polyamide precursor and at least partially polymerizing the second aqueous charge with the second portion of polyetheramine-containing polyamide within the reactor;
- e. heating the reactor at heat input rate Q1 to temperature range T1 and pressure range P1;
- f. reducing the heat input rate to Q2 and holding the reactor at temperature range T2 and pressure range P2 for about 1 minute to about 40 minutes to reduce the water content of the polymerizing mass;
- g. adding polyetheramine to the reactor;
- and
- h. increasing the heat input rate to the reactor to Q3, where Q3 >Q2, and at least partially venting the reactor to control pressure at or below range P1 to form polyetheramine-containing polyamide within the reactor.
6 more elements
Dependencies are inferred from the claim text.