Patent US4472116A successfully refreshed from Google Patents.
Patent EP0078609A2 successfully refreshed from Google Patents.
EP0078609A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
3-Hydroxybutyric acid polymers
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1982-09-30
•
Granted: —
•
Expires: 2002-09-30
Abstract
Abstract A solvent-free preform of a 3-hydroxybutyric acid polymer is subjected to a compression step to reduce its thickness by at least 5% and the compressed preform is then drawn uni- or bi-axially to induce orientation.
Inventors
- 👤 Peter John Barham
- 👤 Paul Arthur Holmes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 13:39
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/04; C07D295/08; C07D295/096; C07C; C07C17/00; C07C17/093; C07C17/16; C07C29/00; C07C29/132; C07C29/136; C07C29/147; C07C405/00; C07C405/0008; C07C405/0033; C07C405/0041; C07C45/00; C07C45/27; C07C45/30; C07D267/00; C07D267/02; C07D267/08; C07D267/10; C07D295/10; C07D295/112; C07D295/14; C07D295/155; C07D307/00; C07D307/77; C07D307/93; C07D307/935; C07D309/00; C07D309/02; C07D309/08; C07D309/10; C07D309/12; C07D311/00; C07D333/00; C07D333/02; C07D333/04; C07D333/06; C07D333/12; C07D333/14; C07D333/16; C07D333/22; C07D333/24; D; D01; D01F; D01F6/00; D01F6/58; D01F6/62; D01F6/625; Y; Y10; Y10S; Y10S428/00; Y10S428/91
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
A process for the production of a shaped article from a polymeric material in which 3-hydroxybutyric acid residues form at least 40 mole % of the polymer chain comprising subjecting a solvent-free preform of the polymer to compressive force at a temperature between the glass transition temperature and the crystalline melting point of the polymer so that its thickness is reduced by at least 5%, and thereafter drawing the compound preform uni- or bi- axially.
Claim 2
Dependent Claim
75 words
A process for the production of a shaped article from a polymeric material in which 3-hydroxybutyric acid residues form at least 40 mole % of the polymer chain comprising subjecting a solvent-free preform of the polymer to compressive force at a temperature between the glass transition temperature and the crystalline melting point of the polymer so that its thickness is reduced by at least 5%, and thereafter drawing the compound preform uni- or bi- axially.
Claim 3
Dependent Claim
30 words
A process according to claim 1 wherein the preform is subjected to said compressive force at a temperature between 50 and 150°C below the crystalline melting point of the polymer.
Claim 4
Dependent Claim
30 words
A process according to claim 1 or claim 2 wherein the compressed preform is drawn at a temperature between 40 to 90°C below the crystalline melting point of the polymer.
Claim 5
Dependent Claim
26 words
A process according to any one of claims 1 to 3 wherein the preform is compressed by pressing the preform between the plattens of a press.
Claim 6
Dependent Claim
29 words
A process according to any one of claims 1 to 3 wherein the preform is compressed by passing the preform through the nip of a pair of nip rollers.
Claim 7
Dependent Claim
26 words
A process according to any one of claims 1 to 3 wherein the preform is compressed by solid state extrusion of the preform through a die.
Claim 8
Dependent Claim
38 words
A process according to claim 5 wherein the preform is passed between the nip of a pair of nip rollers prefiled corresponding to the desired cross-section of the compressed preform and then the rolled preform is drawn uniaxially.
Claim 9
Dependent Claim
24 words
A process according to any one of claims I to 7 wherein the draw ratio, in at least one direction, is at least 1.5:1.
Claim 10
Dependent Claim
91 words
A process according to any one of claims 1 to 8 wherein the amount of compression and the draw ratio in the drawing step are such that the overall draw ratio in at least one direction is at least 3:1. 100 A process according to claim 9 wherein the compressed preform is drawn uniaxially and the amount of compression and the draw ratio in the drawing step are such that the length of the drawn preform is at least four times the length of the preform prior to the compression step.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.