Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
  • H01B7/29—Protection against damage caused by extremes of temperature or by flame
  • H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
  • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
  • H01B3/44—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins
  • H01B3/441—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins from alkenes

Definitions

• the present invention relates to compositions which have improved insulation resistance stability and to methods of preparation thereof. More specifically, the invention relates to compositions which have improved insulation resistance stability in water so that compositions can be employed in forming insulation layers which are thinner by a substantial amount than previous insulations and yet provide adequate or improved degrees of insulation resistance stability.
• compositions which have relatively high insulation resistance stability.
• crosslinked polyethylene compositions prepared generally according to the teachings of the Gilbert and Procopio patents numbers 2,888,442 and 3,079,370 assigned to the same assignee as the subject application.
• One object of the present invention is to provide novel insulation compositions which make possible reduction in the thickness of a deposited layer of insulation without loss of important electrical properties such as the insulation resistance stability.
• Another object is to provide a method of forming such novel wire and cable products insulated therewith.
• Still another object of the invention is to provide wire insulated with compositions which have improved insulation resistance stability.
• Another object is to provide insulated wires which have relatively thinner layers of insulation but which have properties which are equal to or superior to insu lation layers of thicker dimensions.
• Another object of this invention is to provide methods for forming such insulated articles.
• Another object is to provide a composition particularly suitable for use in insulating cables to be employed in damp and wet locations, including wet locations which are at elevated temperatures.
• Another object is to provide a composition as in the prior object for insulating power cables for use in wet locations including use at elevated temperature in wet locations.
• Another object is to improve the insulation resistance stability of compositions which contain highly polar organic flame retardants.
• Another object is to provide compositions having improved insulation resistance stability.
• Another object is to provide articles insulated with compositions having improved insulation resistance stability. Another object is to provide crosslinkable compositions having improved insulation resistance stability. Other objects will be in part apparent and in part pointed out hereinafter.
• Objects of the present invention are achieved by combining polyolefin base polymer with polar organic additives and by including in the composition antioxidants which cause surprising increase in the insulation resis tance and in the insulation resistance stability of the resultant composition.
• the polar organic additives may be organic halogenated flame retardants such as deca bromodiphenyl oxide and the antioxidants may be a zinc salt of a mercaptoimidazole and a sterically hindered di tertiary butyl phenol.
• the composition may contain other conventional additives.
• composition may also be crosslinked and such crosslinking may be by high energy radiation such as high energy electrons or be conventional chemical crosslinking agents such as organic peroxides.
• FIGURE 1 is a graph of the test data obtained from measurement of the insulation resistance of a number of compositions measured in megaohms against time indicated as the abcissa in weeks.
• FIGURE 2 is a perspective view of a wire formed pursuant to the present invention having a central conductor and an insulating layer about the conductor.
• FIGURE 3 is a graph of the specific inductive capacitance and the percent power factor against time in weeks.
• DESCRIFTION OF A PREFERRED EMBODIMENT As indicated above, a novel feature of the present invention is a composition which contains a highly polar additive but which also has a high insulation resistance as well as a high insulation resistance stability.
• composition itself has a polyolefin base polymer composition and other ingredients are combined with the polyolefin base as set out below.
• a first ingredient is an organic flame retardant which has been the subjectof a special treatment preparation procedure.
• a treated flame retardant used and Useful in practice of the present invention is a pretreated composition described in essential details in the U.S. Patent 4,209,566 assigned to the same assignee as the subject application, which patent is hereby incorporated herein by reference.
• Such flame retardant includes both, a set of ingredients and a treatment of the ingredients including an ovenizing treatment.
• the set of ingredients, as well as their proportions, are set forth in Table I below.
• a first ingredient of the pretreated composition is an organic halogenated flame retardant.
• the organic halogenated flame retardant may preferably be the decabromodiphenyl oxide or decabromodiphenyl ether, but may also be ethylene bis (tetrabromophthalimide) sold commercially under the designation BT-93 by Saytech Corporation, or a brominated diphenyl oxide of a lower degree of bromination.
• the stable organic halogenated flame retardant may be employed, such, as the chlorinated flame retardant available commercially under the trade name Dechlorane of Hooker Chemical Corporation.
• the treated flame retardant also contains antimony oxide.
• the antimony oxide flame retardant used in the treated flame retardant of the present invention is the conventional or standard powdered compound.
• the treated flame retardant used and useful in the present invention also includes a fumed silica ingredient.
• fumed silica found useful in preparation of a suitable treated flame retardant is one sold commercially under the designation Cabosil MS7 and available from CL. Cabot Inc. of Boston, Massachusetts.
• the treated flame retardant useful in the present invention also includes a silicone fluid ingredient, which is a reactive silicone such as is described in the U.S. Patent 4,209,566 assigned to the same assignee as the subject application.
• the treated flame retardant useful in the pre sent invention is prepared by a heat treatment procedure which may typically be a baking of the weli-mixed ingre washers described above at a temperature of about 375°F for a period of 16 hours.
• a heat treatment procedure which may typically be a baking of the weli-mixed ingre washers described above at a temperature of about 375°F for a period of 16 hours.
• Table I sets forth the ingredients and makeup of a special flame retardant additive useful in combination with polyethylene and other ingredients in carrying out the present invention. Consideration is given next to the other ingredients of the novel compositions of this invention.
• the polyolefin as used herein refers to polyethylene as a preferred component, but the polyolefin may also be copolymers of ethylene, including but not limited to ethylene ethyl acrylate, ethylene vinyl acetate copolymers, ethylene-butene copolymers, ethylene-propylene copolymers, terpolymers and quatrepolymers such as EPDM. Also, the polyolefin may be either of the high density or the low density polyethylene or may be polyallomer.
• Dibasic lead phthalate composition or ingredient may be used in the composition of this invention and may be any organic lead compound in which the lead proportion is roughly equivalent to that of the dibasic lead phthalate or greater.
• organic lead compounds which have low volatility and which result in suitable stabilization properties may be employed but the dibasic lead phthalate is the preferred compound for this ingredient.
• stabilization is meant that the lead compound can scavenge free halogen from the composition.
• Silicone gum can be used as an optional ingredient and is accordingly included as such in Table II below, as is the dibasic lead phthalate.
• the silicone gum useful in the novel composition of this invention is described in copending application Serial No. 196,989 filed October
• the peroxide curing agent as indicated may be an organic peroxide which decomposes, i.e. generates free radicals, at the elevated temperatures above the basic mixing temperatures and may be, as in the examples given, dicumyl peroxide.
• materials sold under the commercial designation Vul-Cup R may be employed although the cost is higher than that of the dicumyl peroxide.
• Such organic peroxides are known in the art and in the patent literature directed to this art and are described in part in the patents referenced above which patents are incorporated herein by reference.
• the bromine containing treated flame retardant is as described above.
• additives conventionally used in polyolefin base polymer composition used in wire insulation may also be added and included.
• conventional fillers, pigments, curing coagents, and other conventional additives including preservatives such as modifying agents, mold release ingredients, processing aids or lubricants and the like and commonly employed with polyolefins in addition to the essential ingredients set forth above and hereinafter such as the pre-processed flame retardant and the special combination of antioxidants may be used.
• the octamethyltetracyclosiloxane ingredient is a reactive silicone fluid which is commercially available from General Electric Company at Waterford, New York, under the trade designation SC-3636 and is an optional ingredient in the compositions of the subject application.
• the ingredients of Table I are used as a single pretreated ingredient in the combination of ingredients as set out in Table II below.
• the peroxide ingredient of the composition may be omitted and high energy radiation, such as high energy electrons, can be employed to cause crosslinking and curing of the coating composition also by methods well known in the art.
• high energy radiation such as high energy electrons
• FIG 2 there is illustrated a central conductor 12 about which has been formed an insulating layer 14 prepared pursuant to the present invention.
• the insulating layer 14 may be in the curable state or may be in the cured state. Also, the cured insulation may be chemically cured or cured by high energy radiation.
• the product illustrated is an insulated conductor 10, the conductor of which may be solid as illustrated or stranded.
• the first is the SIC, or specific inductive capacitance, and the second is the percent power factor at 80 volts per mil.
• the scales for the two sets of tests are different so that although the graphs are plotted relatively close to each other, they actually correspond to different values which are values used for the respective ordinates of the graph.
• the samples were tested at intervals represented by the dots and, prior to each such, test, the wire sample being tested was subjected to a so-called "high pot" test which involved the imposition of a high voltage, of 2.4 kilovolts, to the conductor of the wire as the insulated portion of the wire was immersed in a water bath at a temperature of 75°C.
• the graph data demonstrates that the power factor was quite remarkably low for a flame retardant composition and, in addition, that the power factor remained very stable and showed essentially no increase overall during the entire 66-week period of the test. Based on the foregoing, it is evident that the composition of the present invention is unique in providing both flame retardancy in combination with a unique set of electrical properties of remarkable stability for an insulating material which contains the type of flame re tardant which is present in the subject material.
• Example 1 a single set of the first set of ingredients, including all ingredients other than antioxidants, was chosen and the quantities of these ingredients was constant for all tests performed including Tests A, B,
• Tests D and E are compared to the graphs for Tests A, B and C which have the compositions as listed in Example 1, Table III. All com positions had all ingredients other than the antioxidant ingredients within the range indicated under "Parts by Weight” and in precisely the same proportions and amounts for each of the test samples A through E as indicated by the designation "same".
• the significant difference in ingredient content involved only the use of different antioxidants and combinations of antioxidants, and particularly, the combination of the Vulkanox ZMB and one of the Irganox antioxidants. It is evident that a very dramatic improvement in insulation resistance and insulation resistance stability is demonstrated by Test plots A, B, C, D and E of Figure 1.
• the individual curves of plotted data correspond to the individual compositions which are set out in Table III,
• Table III the test composition labelled A through E are marked with the letters used at the head of the column for the data recorded for the compositions employed.
• each composition was the same in its constituents and in the proportions of the constituents, other than the antioxidants.
• the conventional Agerite and Santowhite antioxidants as well as the zinc salt of a mercaptoimidazole and the sterically hindered di-tertiary butyl phenol, were changed as indicated but none of the proportions or concentrations of the other ingredients varied from the composition for Graph A through the composition for Graph E.
• the UL test used in obtaining the test data is UL Test 83 for Thermoplastic Insulated Wires and Cables, and UL Test 44 for Rubber Insulated Wires and Cables.
• the insulation resistance stability for a wire formed with a 14 AWG internal conductor and a 30 mil wall thickness and tested at 75°C in water with 600 volts AC applied are given.
• the first curve A shows that the insulation resistance rose from a low value to a maximum of approximately 1300 in a period of 30 to 35 weeks and that thereafter the insulation resistance declined with the passage of time.
• the curve is so marked on the drawing and it is evident that in a period of about 25 weeks, the curve reached a maximum value of about 5000 megaohms and that thereafter there was a fairly rapid decline in the value of the insulation resistance measured.
• the composition for which Graph A was plotted contained neither of the special antioxidants, but did contain a conventional combination of antioxidants, namely, the Agerite MA and Santowhite Crystals, in the ratio of 1.5 for Agerite MA and 0.25 for the Santowhite Crystals, and that in Graph B the value of the Agerite MA and Santowhite Crystals was doubled from the values in Graph A.
• a significant in crease in the insulation resistance bccured but there was also a very rapid decline in the insulation resistance.
• the 30 mil sample absorbed more than 50% more than the 20 mil sample.
• both samplesr passed the UL-94 vertical flame test.
• both samples passed the VW-1 test, the most difficult flame test procedure used in the wire and cable field.
• the toluene extraction percent for each of the two samples is essentially the same.
• Both samples passed the IEEE 383 and 323 qualification test. All of the foregoing tests are standard tests and descriptions thereof can be obtained from standard references and from other patents which deal with essentially the same subject matter as the subject application.
• the particular sample of wire which, was used in each of the tests was a #12/19 tinned stranded conductor. In other words, the wire had nineteen tinned strands.

Landscapes

• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Organic Insulating Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Insulated Conductors (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=23223957

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (2)

Citations (2)

Family Cites Families (2)

• 1982
  • 1982-09-03 AU AU89533/82A patent/AU568802B2/en not_active Ceased
  • 1982-09-03 WO PCT/US1982/001196 patent/WO1983001415A1/en not_active Application Discontinuation
  • 1982-09-03 JP JP57502946A patent/JPS58501794A/ja active Pending
  • 1982-09-03 EP EP19820902886 patent/EP0091910A4/de not_active Ceased
  • 1982-10-19 IT IT23810/82A patent/IT1152731B/it active
  • 1982-10-20 IN IN1240/CAL/82A patent/IN159508B/en unknown

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events