US4775501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat recoverable article comprising conductive polymer compositions
Assignee: Central Plastics Co
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Filing: 1985-04-02
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Granted: 1988-10-04
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Expires: 2005-04-02
Abstract
Abstract A method of joining, repairing or reinforcing substrates, particularly polymeric pipes for transporting fluids, e.g. natural gas and water. The method makes use of an article, preferably a heat-recoverable article, which comprises a conductive polymer composition and which is heated to its recovery temperature by passing electrical current through the conductive polymer. Preferably the article is a heat-shrinkable coupler. The coupler may make direct contact with and fuse to the pipes, or there may be an insert between the coupler and the pipes. The article preferably comprises carbon black dispersed in either a sintered polymer, particularly ultra high molecular weight polyethylene or a very high molecular weight polymer, particularly polyethylene having a molecular weight greater than 150,000.
Inventors
- 👤 Nachum Rosenzweig
- 👤 Pravin L. Soni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:13
CPC Classifications
B; B29; B29C; B29C66/00; B29C66/50; B29C66/51; B29C66/52; B29C66/522; B29C66/5221; B29C61/00; B29C61/003; B29C61/06; B29C61/0608; B29C61/0625; B29C65/00; B29C65/66; B29C65/68; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/114; B29C66/12; B29C66/122; B29C66/1222; B29C66/1224; B29C66/124; B29C66/1244; B29C66/12441; B29C66/5224; B29C66/52241; B29C66/5229; B29C66/52291; B29C66/52293; B29C66/63; B29C66/636; F; F16; F16L; F16L47/00; F16L47/20; F16L47/22; F16L55/00; F16L55/16; F16L55/168; F16L55/17; B29C66/70; B29C66/71; B29C66/72; B29C66/721; B29C66/7212; B29C66/73; B29C66/737; B29C66/7375; B29C66/73755; B29C66/73756; B29C66/739; B29C66/7392; B29C66/73921; B29C66/7394; B29C66/73941; B29C66/90; B29C66/91; B29C66/914; B29C66/9141; B29C66/91411; B29C66/91441; B29C66/91443; B29C66/91445; B29C66/9161; B29C66/91651; B29C66/91653; B29C66/91655; B29C66/919; B29C66/94; B29C66/949; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0658; B29K2023/0675; B29K2023/0683; B29K2707/00; B29K2707/04; B29K2995/00; B29K2995/0003; B29K2995/0005; B29K2995/0037; B29K2995/0088
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
217 words
A method of joining, repairing, reinforcing or otherwise modifying a substrate having at least one outer surface which is composed of a first composition which is a heat-softenable composition comprising an organic polymer, which method comprises 1. placing adjacent to the substrate an article comprising a heat-recoverable element, the heat-recoverable element being at least 0.1 inch thick, having a recovery temperature TR, and being composed of a second composition which (a) is compatible with the first composition; (b) comprises (i) a matrix consisting essentially of organic polymer particles which have been sintered together so that the particles have coalesced without completely losing their identity, and (ii) a particulate conductive filler which is dispersed in said matrix but is present substantially only at or near the boundaries of the coalesced particles; and (c) increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)° C.; 2. generating heat within said element by passing electrical current therethrough, thus causing the element to recover into direct physical contact with the outer surface of the substrate; and 3. continuing to generate heat within said element by passing electrical current therethrough after it has recovered into contact with the substrate, so as to cause fusion (as hereinbefore defined) between the element and said outer surface.
Claim 2
Independent Claim
217 words
A method of joining, repairing, reinforcing or otherwise modifying a substrate having at least one outer surface which is composed of a first composition which is a heat-softenable composition comprising an organic polymer, which method comprises 1. placing adjacent to the substrate an article comprising a heat-recoverable element, the heat-recoverable element being at least 0.1 inch thick, having a recovery temperature TR, and being composed of a second composition which (a) is compatible with the first composition; (b) comprises (i) a matrix consisting essentially of organic polymer particles which have been sintered together so that the particles have coalesced without completely losing their identity, and (ii) a particulate conductive filler which is dispersed in said matrix but is present substantially only at or near the boundaries of the coalesced particles; and (c) increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)° C.; 2. generating heat within said element by passing electrical current therethrough, thus causing the element to recover into direct physical contact with the outer surface of the substrate; and 3. continuing to generate heat within said element by passing electrical current therethrough after it has recovered into contact with the substrate, so as to cause fusion (as hereinbefore defined) between the element and said outer surface.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein the substrate is a pipe.
Claim 4
Dependent Claim
36 words
A method according to claim 2 which comprises joining together two substantially identical pipes which are in-line and each of which consists essentially of the first composition; and said article is a hollow, radially heat-shrinkable coupler.
Claim 5
Dependent Claim
24 words
A method according to claim 1 wherein the organic polymer is a ultrahigh molecular weight polyethylene having a molecular weight greater than 1.5 million.
Claim 6
Dependent Claim
33 words
A method according to claim 4 wherein the second composition has a resistivity at 23° C. of 1 to 100 ohm.cm and contains less than 9% by volume of a particulate conductive filler.
Claim 7
Dependent Claim
27 words
A method according to claim 1 wherein the second composition has a high load melt index, measured by ASTM D1238 Condition F 190/21.6, of less than 25.
Claim 8
Dependent Claim
19 words
A method according to claim 1, wherein the heat recoverable element comprises two or more layers of different materials.
Claim 9
Dependent Claim
29 words
A method according to claim 7, wherein one layer comprises organic polymer and dispersed in the polymer a particulate conductive filler, and another layer comprises a non conductive layer.
Claim 10
Dependent Claim
87 words
A method according to claim 1 wherein the second composition (a) has a resistivity at 23° C. for 1 to 100 ohm.cm, and (b) comprises (i) a matrix consisting essentially of particles of ultra high molecular weight polyethylene which have been sintered together so that the particles have coalesced without losing their identity, and (ii) less than 9% by volume of a particulate conductive filler which is dispersed in said matrix but is present substantially only at or near the boundaries of the coalesced particles of polyethylene.
Claim 11
Dependent Claim
17 words
A method according to claim 9 wherein the polyethylene has a molecular weight greater than 4.0 million.
Claim 12
Dependent Claim
20 words
A method according to claim 9 wherein the conductive polymer composition contains 2 to 6% by volume of carbon black.
Claim 13
Dependent Claim
140 words
A method according to claim 2 wherein the end of a first pipe is joined as a branch into a second pipe, which method comprises 1. making a hole in the wall of the second pipe; 2. placing the article adjacent the second pipe, the article (a) comprising a section which conforms generally to the wall of the second pipe and which has a hole therethrough and (b) being heat-recoverable in the area adjacent the hole so that when the article is heated the size of the hole decreases, and the hole in the article being aligned with the hole in the second pipe; 3. placing the end of the first pipe through the hole in the article; and 4. passing electrical current through the conductive polymer element to cause the article to recover into contact with the first pipe.
Claim 14
Dependent Claim
52 words
A method according to claim 12 wherein the end of the first pipe passes through the hole in the wall of the second pipe; the first pipe and the second pipe are composed of a said first composition; and the article becomes fused to both the first pipe and the second pipe.
Claim 15
Dependent Claim
24 words
A method according to claim 2 which comprises placing a hollow support member within at least one of the pipes before recovering the article.
Claim 16
Dependent Claim
19 words
A method according to claim 1 wherein said article consists essentially of the heat-recoverable element and electrodes secured thereto.
Claim 17
Dependent Claim
30 words
A method according to claim 15 wherein the heat-recoverable element is a cylindrical radially heat-shrinkable article and the electrodes are annular electrodes positioned at the ends of the heat-recoverable element.
Claim 18
Dependent Claim
34 words
A method according to claim 1 wherein the conductive polymer increases in resistivity by a factor of less than 2 over the temperature range 23° C. to (TR+50)°C., where TR is the recovery temperature.
Claim 19
Dependent Claim
42 words
A method according to claim 1 wherein the first composition comprises a polymeric component in which at least 30% of the recurring units are the same as at least 30% of the recurring units in the polymeric component of the second composition.
Claim 20
Independent Claim
119 words
A method of joining the ends of two polyethylene pipes, which method comprises 1. placing the ends of the pipes, with the pipes in line, within a coupler which consists essentially of a. a hollow radially heat-shrinkable element which has a wall thickness of at least 0.1 inch and which is composed of a conductive polymer composition which i. has a resistivity of 0.5 to 100 ohm.cm at 23° C., ii. increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)°C., where TR is the recovery temperature, and iii. comprises polyethylene and a particulate conductive filler dispersed therein; and b. annular electrodes positioned at the ends of the heat-shrinkable element; and
Claim 21
Independent Claim
119 words
A method of joining the ends of two polyethylene pipes, which method comprises 1. placing the ends of the pipes, with the pipes in line, within a coupler which consists essentially of a. a hollow radially heat-shrinkable element which has a wall thickness of at least 0.1 inch and which is composed of a conductive polymer composition which i. has a resistivity of 0.5 to 100 ohm.cm at 23° C., ii. increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)°C., where TR is the recovery temperature, and iii. comprises polyethylene and a particulate conductive filler dispersed therein; and b. annular electrodes positioned at the ends of the heat-shrinkable element; and
Claim 22
Dependent Claim
26 words
passing current through the element, thus heating the element so that it shrinks into direct physical contact with the pipes and becomes fused to the pipes.
Claim 23
Dependent Claim
26 words
passing current through the element, thus heating the element so that it shrinks into direct physical contact with the pipes and becomes fused to the pipes.
Claim 24
Dependent Claim
67 words
A method according to claim 19 wherein the conductive polymer composition consists essentially of (a) a matrix consisting essentially of particles of ultra high molecular weight polyethylene which have been sintered together so that the particles have coalesced without losing their identity, and (b) a particulate conductive filler which is dispersed in said matrix but is present substantially only at or near boundaries of the coalesced particles.
Claim 25
Dependent Claim
26 words
A method according to claim 20 wherein the conductive filler is carbon black and is present in amount 2 to 6% by volume of the composition.
Claim 26
Dependent Claim
38 words
A method according to claim 19 wherein the coupler has been prepared by melt-shaping a conductive polymer composition which consists essentially of polyethylene having a molecular weight greater than about 200,000 and a particulate conductive filler dispersed therein.
Claim 27
Dependent Claim
26 words
A method according to claim 22 wherein the conductive filler is carbon black and is present in amount less than 24% by weight of the composition.
Claim 28
Independent Claim
36 words
A method of joining, repairing, reinforcing or otherwise modifying a substrate having at least an outer surface which is composed of a first composition which is a heat-softenable composition comprising an organic polymer, which method comprises
Claim 29
Independent Claim
36 words
A method of joining, repairing, reinforcing or otherwise modifying a substrate having at least an outer surface which is composed of a first composition which is a heat-softenable composition comprising an organic polymer, which method comprises
Claim 30
Dependent Claim
151 words
placing adjacent to the substrate an article comprising a melt-shaped heat-recoverable element, the heat-recoverable element being at least 0.1 inch thick, having a recovery temperature TR, and being composed of a second composition which (a) is compatible with the first composition, (b) comprises (i) an organic polymer having a molecular weight of at least 150,000 and (ii), dispersed in the polymer, a particulate conductive filler; and (c) increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)°C.; 2. generating heat within said element by passing electrical current therethrough, thus causing the element to recover into direct physical contact with the outer surface of the substrate; and 3. continuing to generate heat within said element by passing electrical current therethrough after it has recovered into contact with the substrate, so as to cause fusion (as hereinbefore defined) between the element and said outer surface.
Claim 31
Dependent Claim
151 words
placing adjacent to the substrate an article comprising a melt-shaped heat-recoverable element, the heat-recoverable element being at least 0.1 inch thick, having a recovery temperature TR, and being composed of a second composition which (a) is compatible with the first composition, (b) comprises (i) an organic polymer having a molecular weight of at least 150,000 and (ii), dispersed in the polymer, a particulate conductive filler; and (c) increases in resistivity by a factor of less than 5 over the temperature range 23° C. to (TR+50)°C.; 2. generating heat within said element by passing electrical current therethrough, thus causing the element to recover into direct physical contact with the outer surface of the substrate; and 3. continuing to generate heat within said element by passing electrical current therethrough after it has recovered into contact with the substrate, so as to cause fusion (as hereinbefore defined) between the element and said outer surface.
Claim 32
Dependent Claim
12 words
A method according to claim 24 wherein the substrate is a pipe.
Claim 33
Dependent Claim
37 words
A method according to claim 25 which comprises joining together two substantially identical pipes which are in line and each of which consists essentially of the first composition, and said article is a hollow, radially heat-shrinkable coupler.
Claim 34
Dependent Claim
24 words
A method according to claim 26 which comprises placing a hollow support member within at least one of the pipes before recovering the article.
Claim 35
Dependent Claim
33 words
A method according to claim 24 wherein the second composition has a resistivity at 23° C. of 1 to 100 ohm.cm and contains less than 26% by weight of a particulate conductive filler.
Claim 36
Dependent Claim
28 words
A method according to claim 24 wherein the second composition increases in resistivity by a factor of less than 2 over the temperature range 23° C. to (TR+50)°C.
Claim 37
Dependent Claim
27 words
A method according to claim 24 wherein the second composition has a high load melt index, measured by ASTM D1238 Condition F 190/21.6, of less than 25.
Claim 38
Dependent Claim
20 words
A method according to claim 30 wherein the second composition has a high load melt index of less than 20.
Claim 39
Dependent Claim
13 words
A method according to claim 24 wherein the second composition has been cross-linked.
Claim 40
Dependent Claim
24 words
A method according to claim 24 wherein the organic polymer in the second composition is polyethylene having a molecular weight of at least 200,000.
Claim 41
Dependent Claim
19 words
A method according to claim 24 wherein said article consists essentially of the heat-recoverable element and electrodes secured thereto.
Claim 42
Dependent Claim
30 words
A method according to claim 34 wherein the heat-recoverable element is a cylindrical radially heat-shrinkable article and the electrodes are annular electrodes positioned at the ends of the heat-recoverable element.
Claim 43
Dependent Claim
42 words
A method according to claim 24 wherein the first composition comprises a polymeric component in which at least 30% of the recurring units are the same as at least 30% of the recurring units in the polymeric component of the second composition.
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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) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |