Raychem Limited

Orcon Corporation

Eugene F Lopez

Leon C Glover

Bruce D Campbell

Bernard J Lyons

James A Rinde

Christian A Debbaut

Wendell W Moyer

Patrick K Tsou

Norman A Gac

Robert T Zajdel

Dennis A Caponigro

Michael J Dooley

T Kregg Cammack, Ii

Hemang Shah

Anthony Charles Evans

Leon Conrad Glover, Jr

David Terrell

The invention provides a reinforced film or reinforced metallized film, in which the reinforcing yarns in the fill and/or warp direction are coated with hot melt adhesive and placed in contact with the reinforced film, under heat and pressure, to melt the hot melt adhesive and bond the coated yarns to the film.

Film reinforced with yarn coated with hot melt adhesive

The invention provides a substantially flat film or metallized film, reinforced with regularly spaced reinforcing yarns in the fill and warp direction having a residual shrinkage of less than about 2.0%, which is dimensionally stable over a wide range of temperatures, along with a process for producing the same. Synthetic reinforcing yarns, including nylon yarns, can be preshrunk by heating the spooled yarn in an inert atmosphere for a sufficient period of time to reduce the residual shrinkage in the spooled yarn to less than about 2.0%. This preshrunk yarn can then be bonded to a film or metallized film substrate using a wide variety of adhesives, including hot melt adhesives, or water-based adhesives cured by application of heat. Because the residual shrinkage in the reinforcing fibers has been reduced, subsequent application of heat during manufacturing processes, or in the use environment, will not produce the curling or puckering of the film or separation of the metal layer.

Dimensionally stable reinforced film

A self-extinguishing blanket comprises an insulating layer of glass fiber strands which include air spaces within the layer. Each surface of the layer has a bi-directional strand reinforced plastic film which extends continuously along the surface for keeping moisture out of the layer. Each plastic film is attached to the associated surface of the insulation layer by non-contiguous, longitudinally and laterally spaced apart areas of a thermoplastic adhesive. The adhesive areas provide attachment between the strand reinforcement and the layer of glass fiber strands. Each area of adhesive attachment provides sufficient retention to prevent shifting of the film during the sewing together of peripheral edge portions of the sandwiched plastic films and inner insulation layer as required to produce a selected, peripheral configuration of a blanket package. Each area of adhesive attachment is however small enough to permit ready detachment of the strand reinforcement and associated film from the layer of glass fiber strands upon exposure to the heat of a flame. Each plastic film has a composition and embodies a stress condition which enables a portion of the plastic film, when subjected to a direct flame or to the heat developed by an adjacent flame, to soften, to pull apart, and to shrink and curl back and to continue to curl back sufficiently far so as to prevent heating of that portion of the plastic film to the ignition temperature. This blanket construction leaves only the non-flammable layer of glass fiber strands exposed to the heat of the flame, and the shrinking and curl back of the plastic film prevent both ignition of the plastic film and propagation of the flame through the plastic film.

Self-extinguishing blanket enclosed with plastic films

A splice between two multiconductor cables is protected from ingress of water by a closure which is filled with an expanding foam sealant which provides pressure inside the closure sufficient to force the sealant into the interstices of the splice and the interstices between the conductors in the cable, which pressure is retained in the closure until the sealant cures or hardens.

Protection of cable splice

Novel curable adhesives are solid, substantially free of cross-linking and substantially tack-free at 25.degree. C.; remain substantially uncured when maintained for extended periods at 80.degree. C.; have an initial viscosity of 10.sup.3 to 10.sup.4 poise at 150.degree. C. and cure relatively slowly at 150.degree. C.; and cure rapidly at 200.degree. C. The adhesives preferably contain at least one epoxy resin, particularly an epoxy resin having a softening point of at least 50.degree. C. and an epoxy equivalent weight of at least 200 in combination with an epoxy resin which is liquid at 25.degree. C. or an elastomer or other compatible high molecular weight polymer. The adhesive preferably also contains a high temperature curing agent and preferably also a filler, which may be particulate or fibrous. The novel adhesives are particularly useful in combination with heat-recoverable devices, e.g. devices comprising components made of heat-recoverable metal.

Adhesives and devices coated therewith

A method of making a composite structure comprising an elongate substrate, especially an insulated electrical cable, and a covering member which has been heat-recovered and sealed around the substrate. A heat-recoverable article of a cross-linked crystalline polymer composition which transmits 5-50% of infra-red radiation incident thereon is placed around a substrate whose exterior is composed of a polymeric composition which is at most lightly cross-linked, which absorbs infra-red radiation and which has a crystalline melting point below that of the heat-recoverable article. The assembly is exposed to infra-red radiation such that the heat-recoverable article is heated to its recovery temperature and the exterior of the substrate is heated to its crystalline melting point, preferably before it is contacted by said article as it recovers. In this way an excellent seal can be created between the substrate and the recovered article without the need for any auxiliary fusible material such as a hot melt adhesive.

Heat-recoverable articles and their use

An improved method for indicating the temperature to which a heat-deformable polymeric material coated with a thermochromic paint has been heated is disclosed. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phosphorus; the oxides and hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic derivatives and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Method for coating a polymeric article with a thermochromic paint

The ends of heat-recoverable polymeric sheet material are joined by overlapping the ends and bonding them together by means of a laminar panel comprising a layer of a crosslinked hot-melt adhesive coated on one surface of a reinforced polymer layer. The panel has a width approximately that of the sheet material being joined. The panel is disposed, adhesive side down, so that approximately half of its adhesive coated surface contacts the sheet material on either side of the line defined by the uppermost of the overlapping ends. The panel is heated to activate the adhesive and form a secure bond joining the ends. Heat-recoverable sleeves can be made by joining the opposing ends of a single length of heat-recoverable sheet material.

Method for joining heat-recoverable sheet material and resulting article

An article comprising a polymeric material and coated with a thermochromic paint. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phoshorus; the oxides and the hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic compounds and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Polymeric article coated with a thermochromic paint

A thermochromic paint, which changes color when heated to a certain temperature, and which is particularly suited for use on plastic substrates which are subject to oxidative degradation is disclosed. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phosphorus; the oxides and hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic compounds and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Thermochromic paint for use on plastic substrates

A hot melt adhesive composition comprising a compatible mixture of: (a) an acidic ethylene polymer having an acid number ranging from about 3 to about 80 and (b) a polyamide having an amine number ranging from about 70 to about 400, together with a minor effective amount of a tackifying agent; components (a) and (b) being present in a relative proportion by weight ranging from about 80:20 to 20:80. An encapsulation method utilizing said adhesive is also described.

Hot melt adhesive composition comprising an acidic ethylene polymer and

Coherent articles essentially comprised of a mastic material uniformly dispersed throughout a cross-linked polymeric matrix may be employed in, eg, sheet form as sealants for wire and cable terminations, pipe junctions and the like. Adjacent layers of the articles may be amalgamated by heating, yet they are sufficiently crosslinked as to permit the impartation of heat recoverability.

Growing community of inventors

Sunnyvale, CA, United States of America

Eugene F Lopez