US4399265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of products UV-stabilized polyester materials
Assignee: Garware Hi Tech Films Ltd
•
Filing: 1983-01-19
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Granted: 1983-08-16
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Expires: 2003-01-19
Abstract
Abstract Polyesters are combined with UV-stabilizing substances in order to produce an end product, such as a film, sheet, ribbon or filament, by mixing polyester granules and the UV-stabilizing substance in powdered form at an elevated temperature such that at least the exterior surface of the polyester granules is soft, thereby to cause the powdered UV-stabilizing substance to adhere to the individual polymer granules, the granules with the powder adhering thereto are then dried, and they are then passed through an extruder or otherwise formed into an end product.
Inventors
- 👤 Shashikant B. Garware
- 👤 Ramaswamy Ananthanarayanan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:21
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02; C08J; C08J3/00; C08J3/20; C08J3/203; C08K; C08K5/00; C08K5/0008; C08K5/005; C08K5/04; C08K5/13; C08J2367/00; C08J2367/02
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
86 words
The process of producing UV-stabilized polyester materials which comprises: (1) heating polyester granules to a temperature of about 150°-180° C.; (2) mixing a powdered UV-stabilizing substance with said heated granules, thereby producing polyester granules to which said powdered substance is attached; (3) then subjecting said powder-carrying granules to a drying step effective to reduce the moisture content thereof to no more than about 0.005% by weight; and (4) then forming said dried powder-carrying granules into a useful body, such as a film, sheet, ribbon or filament.
Claim 2
Dependent Claim
86 words
The process of producing UV-stabilized polyester materials which comprises: (1) heating polyester granules to a temperature of about 150°-180° C.; (2) mixing a powdered UV-stabilizing substance with said heated granules, thereby producing polyester granules to which said powdered substance is attached; (3) then subjecting said powder-carrying granules to a drying step effective to reduce the moisture content thereof to no more than about 0.005% by weight; and (4) then forming said dried powder-carrying granules into a useful body, such as a film, sheet, ribbon or filament.
Claim 3
Dependent Claim
12 words
The process of claim 1, in which said polyester comprises polyethylene terephthalate.
Claim 4
Dependent Claim
24 words
The process of claim 2, in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 5
Dependent Claim
24 words
The process of claim 1, in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 6
Dependent Claim
20 words
The process of claim 1, in which, between steps (2) and (3), fines are separated out from the powder-carrying granules.
Claim 7
Dependent Claim
23 words
The process of claim 1, in which said forming step (4) is an extrusion step carried out promptly after the drying step (3).
Claim 8
Dependent Claim
32 words
The process of claim 6, in which said polyester comprises polyethylene terephthalate and in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 9
Dependent Claim
25 words
The process of claim 6, in which the powder-carrying granules, after being dried in step (3), are directly fed into an extruder and extruded therefrom.
Claim 10
Dependent Claim
21 words
The process of claim 1, in which the drying step (3) is carried out at a temperature of about 180°-200° C.
Claim 11
Dependent Claim
20 words
The process of claim 9, in which the drying step (3) is carried out while the powder-carrying granules are agitated.
Claim 12
Dependent Claim
32 words
The process of claim 10, in which said polyester comprises polyethylene terephthalate and in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 13
Dependent Claim
38 words
The process of claim 9, in which the drying step (3) is carried out while the powder-carrying granules are agitated and fed through a container in which heated gas is provided in flow counter-current to the fed granules.
Claim 14
Dependent Claim
25 words
The process of claim 9, in which the drying step (3) is carried out in a heated tumbler including vacuum means to draw off moisture.
Claim 15
Dependent Claim
86 words
The process of producing UV-stabilized polyester materials which comprises: (1) heating polyester granules to a temperature at which the polymer surface of the granules becomes soft and sticky; (2) agitating said heated polyester granules and mixing them with a powdered UV-stabilizing substance, thereby to cause said powdered substance to adhere to said heated granules; (3) cooling said powder-carrying granules and separating fines therefrom; (4) drying said powder-carrying granules; and (5) then feeding said dried powder-carrying granules into an extruder and extruding the UV-stabilized polyester material therefrom.
Claim 16
Dependent Claim
86 words
The process of producing UV-stabilized polyester materials which comprises: (1) heating polyester granules to a temperature at which the polymer surface of the granules becomes soft and sticky; (2) agitating said heated polyester granules and mixing them with a powdered UV-stabilizing substance, thereby to cause said powdered substance to adhere to said heated granules; (3) cooling said powder-carrying granules and separating fines therefrom; (4) drying said powder-carrying granules; and (5) then feeding said dried powder-carrying granules into an extruder and extruding the UV-stabilized polyester material therefrom.
Claim 17
Dependent Claim
12 words
The process of claim 14, in which said polyester comprises polyethylene phthalate.
Claim 18
Dependent Claim
24 words
The process of claim 15, in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 19
Dependent Claim
24 words
The process of claim 14, in which said UV-stabilizing substance is a member of the group consisting of o-hydroxy benzophenones, benzotriazoles, and mixtures thereof.
Claim 20
Dependent Claim
34 words
The process of claim 13, in which said drying step (4) is carried out in a hopper dryer, and in which the dried granules are fed directly from said hopper dryer into said extruder.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |