FR2586420A1 - ADHERENCE METHOD - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR ATTACHING TO A SUBSTRATE A NON-STICKY FLEXIBLE LAYER FORMED FROM A RAW POLYMERIC MIXTURE INCLUDING A SECONDARY PROPORTION OF LOW DENSITY LINEAR POLYETHYLENE OR OF ISOTACTIC POLYPROPYLENE AND A DOMINANT PROPORTION OF APPROXIMATELY 50 WEIGHT CONSTITUTE OF BUTYL RUBBER, BY STRETCHING THE FLEXIBLE LAYER BEFORE ITS APPLICATION TO THE SUBSTRATE. IT ALSO CONCERNS THE TAPE OR FLEXIBLE LAYER USED IN THIS PROCESS. THE PROCESS CAN BE USED IN A LARGE NUMBER OF APPLICATIONS, FOR EXAMPLE COVERING METAL PARTS, PERFORMING REPAIRS OF CRACKED PROTECTIVE ELEMENTS, SPLICE WIRES AND REPAIRING HOSES WITH LEAKS.

Description

The present invention relates to a method for attaching a non-

  adhesive, flexible, in the form of sheet or ribbon to a substrate by stretching the flexible layer before application to the substrate, to obtain adhesion to the substrate

  as well as the bond or fusion of the superimposed layers.

  Many items need to be coated to protect them from the environment. For example, metal surfaces can be protected by covering them with a coating layer, avoiding this

  makes chemical, oxidative or other attack on the surface.

  The technology for applying these coatings is well known and includes application in solution, by application of a paint, or application in the form of

  sheet or thin ribbon. In the application of these

  In the form of a sheet or ribbon, a separate adhesive layer is generally used to adhere the sheet to the substrate and adhere

  the superimposed layers of the sheet to each other.

  In industrial packaging operations, such as pipe packaging, the conventional practice is to use a sheet having such an adhesive layer, and to slightly stretch the sheet, up to about 5%, to ensure that she is wrapped tightly

around the pipe.

  In electrical applications such as cable splices, a ribbon in the form of a strip of flexible material is stretched and wound, usually spirally around an electrical cable. Superimposed layers tend to merge with each other

  so that they can not be separated easily.

  Previously, these ribbons were based on natural rubber, while the last ribbons that are described in the literature are based on mixtures of synthetic polymers. The patent of the United States of America

  No. 2,569,541 discloses such compositions containing

  polyethylene, butyl rubber, polyethylene and a tackifier resin, compositions requiring the proportion of butyl rubber to be less than 25%, and a tackifier is required to produce a composition for sealing easy. U.S. Patent No. 3,298,992 discloses ribbon compositions containing particular proportions of butyl rubber, polyisobutylene, chlorinated hydrocarbon solvent and a butadiene / styrene copolymer, having a content of high in styrene. In general, these materials, when in the form of rolls without lining, adhere to one another or fuse> so that after a short time it is impossible to unroll them. In order to avoid this problem, self-adhesive tapes have been proposed, with a detachable liner between the superimposed layers. Eliminating the liner takes time and can be difficult when it adheres closely

to the ribbon.

  The present invention is based on the discovery of

  green of certain compositions in the form of sheet or ribbon, which are not adhesive and therefore do not stick when they are wound on themselves in the relaxed state, but which merge and produce a homogeneous mass when they are stretched by at least about 50% and are wrapped around a substrate. The compositions are formed of mixtures

  polymers comprising certain alpha-polymers

  olefins mixed in proportions given to a constituent

  wherein at least about 50% by weight is an isobutylene-isoprene polymer, the remainder being polyisobutylene, ethylene-propylene polymer or natural rubber. They are strong but can be easily stretched without breaking. They own

  good resistance to ozone and are easily handled

  lables in a wide temperature range. The alphaolefin polymers may be isotactic polypropylene or polyethylenes which are generally referred to as low pressure polyethylene. Another aspect of the present invention is the surprising discovery that the presence of a filler or pigment in the ribbon increases the melting rate

  superimposed layers of the ribbon stretched, rolled up.

  According to the Applicant's discovery, there is provided a method for attaching to a substrate a flexible layer having insufficient adhesiveness to

  adhere itself to the relaxed state, said layer

  taking a crude polymeric mixture selected from the group consisting of (all parts being parts by weight) (a) a mixture of about 15 to about 30 parts of linear low density polyethylene and about 70 to about 85 parts of elastomeric polymer and (b) a mixture of about 15 to about 25 parts of isotactic polypropylene and about 75 to about 85 parts of elastomeric polymer, said elastomeric polymer comprising

  about 50 to 100 parts by weight of an isobutylene polymer

  isoprene and 0 to about 50 parts by weight of one or more polymers selected from (i) natural rubber, (ii) an isobutylene homopolymer having a molecular weight of about 50,000 to about 100,000 and (iii) a ethylene propylene polymer containing from about 50 to about 65% by weight of ethylene, said flexible layer being stretched by at least about 50% immediately prior to contact with the substrate, by applying the stretched layer to the substrate in a winding operation and allowing the superimposed layers of said flexible layer to adhere and merge with each other. Furthermore, according to the Applicant's discovery, there is provided a method for attaching to a substrate a flexible layer having insufficient adhesiveness to adhere itself to the relaxed state, said layer comprising a raw polymeric blend selected from the group comprising (all parts being parts by weight) (a) a mixture of about 15 to about 1 parts of linear low density polyethylene and about 70 to about 85 parts of elastomeric polymer, and (b) a mixture of from about 15 to about 20 parts of isotactic polypropylene and from about 80 to about 85

  elastomeric polymer parts, said poly-mixtures

  crude metals (a) and (b) also containing from about 0.5 to about 20 parts by weight, per 100 parts of total polymer, of one or more fillers or pigments,

  said elastomeric polymer comprising about 50 to 100 parts

  by weight of an isobutylene-isoprene polymer and 0 to about 50 parts by weight of one or more polymers

  between (i) natural rubber and (ii) a homo-

  an isobutylene polymer having a molecular weight of from about 50,000 to about 100,000, said flexible layer being stretched by at least about 50% immediately prior to contact with the substrate, by applying the stretched layer to the substrate in a winding operation and allowing the superimposed layers of said flexible layer to adhere-and..fusion

to each other.

  The isobutylene-isoprene polymer may be selected from a polymer containing from about 97 to about 99.5% by weight of isobutylene and from about 0.5 to about 3% by weight of isoprene, and a polymer containing from about 0.5 to about 1.5% by weight of chlorine or about 1.5 to about 2.5% by weight of bromine and about 95 to about 99% by weight of isobutylene and about 0.5 to about 3% by weight of isoprene. These polymers are commercially available and have a molecular weight, expressed as viscosity

  Mooney, from about 30 to about 80 (ML 1 + 8 to 100 C).

  Polyisobutylene elastomer is commercially available as products of various molecular weights. It is prepared using Friedel-Crafts catalysts at low temperature and its production is well known in the art. The preferred polyisobutylene in the crude polymer blend has a Staudinger molecular weight of from about 50,000 to about 100,000, and especially from about 60,000 to about 80,000. Qualities having higher molecular weights, e.g., about 120,000. at around 135,000, give very strong ribbons that are difficult to stretch and do not merge satisfactorily with

  room temperature when stretched and coiled.

  On the other hand, the very low molecular weight grades give ribbons that are adhesive and difficult to handle. Copolymers. elastomers of ethylene and propylene are well known to those skilled in the art and a

  number are commercially available. These co-

  Suitable polymers include CEP (rubber

  ethylene propylene) and MDEP (ethylene terpolymer

  propylene) containing from about 50% to about 65% by weight of ethylene. The third monomer that is used in small amounts in the production of MDEP is a copolymerizable polyene. These polyenes are generally used

  in industry and are unconjugated dienes com-

  taking 5-ethylidene-2-norbornene, 1,4-hexadiene

  and cyclic dienes such as dicyclopentadiene.

  The natural rubber is preferably selected from commercially available grades of SMR rubber. Polyethylene is a well-known commercial product and a large number of grades are available. The old or conventional grades are produced by a high pressure process which is carried out at a

  pressure of about 103,425 x 103 Pa at 344,750 x 103 Pa.

  The polymers produced in this process contain various short-chain and long-chain branches and have densities ranging from about 0.91 to 0.94 g / cm 3. In more recent processes or low pressure processes, the polymer is produced in gas phase fluidized bed reactors at pressures of about 689.5 x 103 to 2068.5 x 103 Pa or in liquid phase reactors . In these low pressure processes, the ethylene units polymerize in a linear fashion and short branches or statistically spaced side chains are incorporated by copolymerization.

  small amounts, up to about 20% by weight, of

  olefins such as propylene, butane, hexene, octene, etc. The frequency and the length of the side chains determine the density of the polymer. The term linear low density polyethylene (LLDPE) is commonly used and, when used herein, it is intended to mean low pressure copolymers having a density of 0.91. at 0.94 g / cm 3, they generally have a molecular weight of about 100,000 to 500,000, those having a molecular weight ranging from about 100,000 to 300,000 being preferred.

  practice of the present invention, while the use of

  High pressure polyethylene production has resulted in ribbons that are weak and tend to adhere themselves to the relaxed state. LLDPE is commercially available in grades within a melt index range, which is a measure of viscosity under melt flow conditions. Those preferred in the practice of the present invention are within a range of

  from about 0.2 to about 5, according to ASTM-D-1238.

  Polypropylene that can be used in the

  practice of the present invention is preferably a poly-

  highly crystalline propylene in which propylene

  is polymerized predominantly in the configu-

  isotactic ration. It can also contain a small

  up to about 15% by weight of the configuration.

  atactic or other copolymerized alpha-olefin such as butene, pentene, hexene, octene, etc. The term polypropylene as used herein includes homopolymers of propylene as well as

  than these copolymers. Many qualities of poly-

  propylene are commercially available, and are within a wide range of melt index. Qualities with a melt index according to the standard

  ASTM-D-1238 ranging from about 2 to about 12 are preferred.

  The relative proportions of thermal polymer

  The plastic and elastomeric polymer used in the present invention are in a narrow range. Expressed in parts per 100 parts of the total polymer in the compositions, the proportion of linear low density polyethylene ranges from about 15 to about 30 parts,

  preferably from about 15 to about 25 parts. The pro-

  polypropylene portion ranges from about 15 to about 25

  parts, preferably from about 15 to about 20 parts.

  The proportions below the lower limits of the above ranges yield sheets or tapes having a degree of adhesiveness that causes self-adhesion when layered in the relaxed or unstretched state, while proportions beyond the upper limits give products in which the superimposed layers do not fuse in a reasonable time to the temperatures

  normal, when stretched and rolled up.

  A filler or pigment may be incorporated into the flexible layer containing linear polyethylene

  low density, where desirable, in a quantity

  up to about 20 parts by weight, based on 100 parts of the total polymer. It can be chosen from the one generally used in rubber compounds, for example carbon black, calcium carbonate, talc, aluminum powder, titanium oxide and zinc oxide. The quantity of a

  charge or a particular pigment that can be used.

  without adversely affecting the tensile and / or melting properties of the flexible layer can be readily determined by those skilled in the art. It has unexpectedly been found that carbon black and pigments, when present in an amount of from about 20 parts to about 20 parts by weight, are actually found to increase the melting rate of the superimposed layers of the drawn sheets or ribbons. Thus, when the higher levels of alpha-olefin polymer are used, it is desirable to incorporate carbon black or a pigment into the compositions. To achieve this effect, it is preferable to use titanium oxide or carbon black, the preferred carbon black being a highly abrasive or super abrasive oven black. For electrical applications in which

  conductivity is desired, it is advantageous to use

  also from 10 to about 30 parts by weight of parts of the total polymers of an electrically conductive carbon black or a metal powder,

like aluminum powder.

  Other optional ingredients may be incorporated into the flexible layer to provide various

  performance. For example, we can add anti-

  oxidants and stabilizers, treatment adjuvants,

  lubricants and flame retardants. The utilisa-

  a separate tackifier is not necessary.

  The flexible layer is prepared by blending methods well known in the art of treating synthetic rubbers using a two-roll mill or an internal mixer. When using a two-roll mill, the thermoplastic polymer is loaded into the mill which has been

  preheated to a suitable temperature,

  typically between about 150 and about 170 C, and is mixed until it melts and forms a band on the rolls of the mill, which usually takes about two minutes. Then the elastomeric polymer (s) and all additives are loaded into the mill and grinding is continued until a uniform mixture is obtained, which usually takes another five minutes. The mixture is removed from the mill as strips of the compound. The compound can easily be produced as a mass by means of an internal mixer by charging the polymers in any order in a preheated mixer and mixing until a uniform compound is obtained, usually in five minutes. about. The sheets of the flexible layer may be prepared for example by passing the compound through a rolling mill or extruder provided with a sheet-producing die. The thickness of the sheet is not critical but generally ranges from about 0.1 to about 5 mm. For most applications, it is preferable to use sheets having a thickness of about 0.3 to about 3 mm. The flexible layer can be used in the form of

  although for various applications it is advantageous

  tagger to use it as ribbon produced by cutting the leaf to obtain ribbons possessing the

desired width.

  The flexible layer, in sheet or ribbon form, is applied to the substrate by stretching it in a direction of at least about 50% and, once extended, by applying it to the substrate.

  substrate, as for example in a winding operation.

  LEMENT. This stretching produces sheets or ribbons having an ability to adhere on their own and the superimposed layers adhere strongly to one another. These merged layers have the appearance of a sheet on or covering the substrate after a few hours of application. In order to obtain the necessary self-adhesion properties, the flexible layer is elongated by at least about 50%. The upper limit of elongation depends on the composition of the particular sheet or ribbon and must be less than the degree that causes the breakage. Preferably, it has been found that an elongation of from about 75% to about 150% provides an optimum balance between obtaining properties

  self-adhesion and avoidance of breakage.

  The method of the present invention can be used in a large number of applications such as splicing, encapsulation and connection. Metal parts can be easily coated with such a flexible layer for storage purposes or because of the environment; for example, a metal pylon can be covered in this way to protect it when immersed in water. Minor repairs may be carried out on existing covers of exposed parts, such as under automobiles, trucks or similar vehicles. Damaged parts ax ends of tie rods or rack-and-pinion steering components can be easily

  repaired by covering them with a compliant flexible layer

  in accordance with the present invention. The method can be used, particularly in the form of ribbons, in electricity for splicing cables, and for repairing damaged fittings and insulators, particularly in

cold environment conditions.

  The following examples illustrate the framework of

the present invention.

Example 1

  Sixty grams of each of the four compounds of a butyl rubber and a linear low density polyethylene were prepared in an internal laboratory mixer in the relative proportions (parts by weight) mentioned in Table I. The butyl rubber was POLYSAR Butyl 301 supplied by Polysar Limited and contained about 98.4% by weight of isobutylene and about 1.6% by weight of isoprene, and had a Mooney viscosity (ML 1 + 12 at 125 C) of about 55. polyethylene was DOWLEX 2045 supplied by Dow Chemical, having a melt index of 1.0 g / 10 min as determined by the method according to ASTM D-1236 and a density of 0.92, as determined by the method. according to ASTM D-792. The internal mixer was preheated to about 160 ° C and the polymers were added and mixed for about 5 minutes. Compounds placed in a rubber mill were removed in the form of a sheet having a thickness of about 1.5 mm and ribbons having a width of 0.6 cm were

cut out in each sheet.

  The degree of adhesiveness of the ribbons in the unstretched state was determined by folding the ribbons, pressing the superimposed layers together, observing the degree of self-adhesion, and the ease with which the layers could be separated by hand. A ribbon of each compound was lengthened

  75 to 100% and wrapped around a metal bar.

  Coiling was examined after overnight resting at room temperature. The results are presented on

Table I.

  Compound / Ribbon N Butyl Rubber Polyethylene Carbon Black Antioxidant

TABLE I

1 2

80

20

3 3

0.05 0.05

  Adhesiveness in the unstretched state ** * * No degree of fusion

(one night at

  ambient high) high medium high * low - separate layers applying very little force ** moderate - separate layers without tearing but

applying a large force.

  Notes: Carbon Black - IRB No 4 Antioxidant - IRGANOX 1010

Example 2

  Using the method of Example 1, the compounds shown in Table II were prepared and tested. The butyl rubber and the polyethylene were the same as those used in Example 1. Comparing the properties of the N 5 tape with those of the tape N 4 of Table I, it is found that the presence of 10 parts of carbon black per 100 parts of total polymer results in a higher degree of melting. Ribbon No. 7, which is outside the scope of the present invention, shows that for the replacement of a portion of the butyl rubber with MDEP, the addition of carbon black substantially suppresses melting. Ribbons Nos. 8 and 9, which are outside the scope of the present invention, show that above the critical content of polyethylene, the melting of the

ribbon does not occur.

  0.05 0.05 Compound / Tape No Butyl Rubber

MDEP 585

  Polyethylene Carbon black Adhesiveness in unstretched state Melting point

(one night at

ambient erasure) Notes:

MDEP 585 -

Carbon black

Example 3

TABLE II

6 7 8 9

80 40 65 65

40 .. ..

20 20 35 35

10 10 10 20

  no zero none zero none high high none zero none Copolymer of ethylene, propylene and ethylene norbornene, containing about

  62% ethylene, supplied by Polysar Limited.

  Type N-330 Using the method of Example 1, three compounds containing 75 parts by weight of POLYSAR-Butyl 301, parts by weight of polyethylene DOWLEX 2045 and 0.05 part of anti-oxidant IRGANOX 1010 were prepared. and tried. The first compound contained no additional material, the second contained an additional 20 parts of carbon black type N-330 and the third contained 21.3 parts of titanium oxide TITANOX ALO (the parts being by weight per 100 parts

total polymer).

  None of the ribbons exhibited adhesiveness in the unstretched state. After stretching and applying, allowing them to stand overnight, the inner layers of the coiled ribbon of the first compound fused although a portion of the outer layer could be unrolled without tearing. The ribbons of the second and third compounds merged, so that the layers did not

could be separated.

Example 4

  A compound containing 48 g of butyl rubber and 12 g of isotactic polypropylene was prepared and tested by the method of Example 1. Butyl rubber, butyl 111, was supplied by Polysar Limited and contained about 99.3% by weight of isobutylene and about 0.7% by weight of isoprene, and had a Mooney viscosity (ML 1 + 8 at 100 C) of about 70.

  polypropylene, from PROFAX 6524, was supplied by Hercules.

  Ribbons prepared from the compound exhibited slight surface tack, but when superimposed and pressed together they did not bond and could be easily separated. A band was stretched

  about 100% and wrapped around a metal bar.

  It remained tightly attached to the bar and the superimposed layers adhered strongly to each other and

merged after 24 hours.

Example 5

  Example 4 was repeated except that 15 g of the poly-

  propylene and 45 g of butyl rubber were used in the preparation of the compound. The unstretched ribbon showed negligible stickiness, while the layers

  superimposed ribbon stretched and rolled adhered to them-

  very strongly. They could be unwound after 24 hours but this required the application of a large force.

Example 6

  Example 4 was repeated except that in place of butyl rubber, brominated butyl rubber was used, containing about 96.1% by weight of isobutylene, about 1.8% by weight of isoprene and about 2.1% by weight bromine and having a Mooney viscosity (ML 1 + 4 at 125 C) of about 52. The unstretched tape exhibited no significant adhesiveness while the superimposed layers of the elongated and rolled tape adhered quite strongly

to each other.

Example 7

  Using the method of Example 1, the compounds shown in Table III were prepared and tested. The butyl rubber was POLYSAR Butyl 301 as used in Example 1, and the polypropylene was the same as that used in Example 3. The carbon black was N-330 carbon black. These results show the critical importance of the amount of polypropylene that can be used in the present invention, the N 12 and 13 ribbons outside the scope of the invention.

TABLE III

  Compound / ribbon N 10 11 12 13 Butyl rubber 80 75 75 70 Polypropylene 20 25 25 30 Carbon black - 0 20 0 Adhesiveness in the not very stretched state low zero zero zero High melting point low zero

Example 8

  Using the method of Example 1, the compounds shown in Table IV were prepared and tested. Ribbons 14 and 15 exhibited slight adhesiveness in the unstretched state. On the other hand, the tapes 16 and 17 which are outside the scope of the present invention exhibited tackiness and the superimposed layers of the undrawn tapes tore apart when effort was made to separate them. In all cases, the stretched and coiled ribbons merged when examined after overnight resting at room temperature.

  Compound / ribbon N Butyl rubber Shell RMT6100 Esso PP00400 Carbon black Antioxidant Adhesiveness in the unstretched state Notes:

TABLE IV

  _ _ 0.5 low adhesive low adhesive Shell RMT6100 and Esso PP00400 isotactic polypropylenes provided respectively by Shell Chemical and Esso Chemical. Carbon black - type N-330 Antioxidant - IRGANOX 1010 Butyl rubber - as used in Example 1

Example 9

  Using the method of Example 1, the compounds shown in Table V were prepared and tested. The butyl rubber was Butyl 301 and the polypropylene was PROFAX 6524, as used in the previous examples. The stretched and coiled ribbons prepared from all the compounds merged when examined after a night's sleep.

rest.

  Compound / Tape N Butyl Rubber Polyisobutylene Natural Rubber

MDEP 585

MDEP 346

  Polypropylene Carbon Black Antioxidant Adhesive in the unstretched state

TABLE V

  _ _ none low low none 0.5 0.5 0.5 42.5 42.5 _ _ 3., 0 0.05 Notes:

  MDEP 585 - as used in Example 2.

  MEDP 346 - copolymer of ethylene, propylene and ethylidene norbornene containing about 62% by weight of ethylene, and supplied by

Polysar Limited.

  Carbon black - type N-330 Antioxidant - IRGANOX 1010

Claims (16)

  A method of attaching to a substrate a flexible layer having insufficient adhesiveness to adhere itself to the relaxed state, characterized in that said layer contains a crude polymeric mixture selected from the group consisting of (all parts being parts by weight)   (a) a mixture of about 15 to about 30 parts of poly-   low density linear ethylene and from about 70 to about 85 parts of elastomeric polymer, and (b) a mixture of   from about 15 to about 25 parts of isomeric polypropylene   and from about 75 to about 85 parts of elastomeric polymer, said elastomeric polymer comprising about 100 parts by weight of isobutylene-isoprene polymer and 0 to about 50 parts by weight of one or more polymers selected from (i) natural rubber, (ii) an isobutylene homopolymer having a molecular weight of about 50,000 to about 100,000 and (iii) an ethylene-propylene polymer containing about 50 to about 65% by weight of ethylene, wherein said flexible layer is subjected to stretch elongation of at least about% immediately prior to contact with the substrate,   applying the stretched layer to the substrate in an   winding ration-and allowing the superimposed layers of said flexible layer to adhere and merge with each others.   The process according to claim 1, characterized in that said isobutylene-isoprene polymer is selected from (a) a copolymer containing from about 97 to about 99.5% by weight of isobutylene and from about 0.5 to about 3% by weight isoprene, having a Mooney viscosity (ML 1+ 8 at 100 C) of from about 30 to about 80, and (b) a copolymer containing from about 95 to about 99% by weight   from about 0.5 to about 2.0% by weight of isobutylene   and about 0.5 to about 1.5% by weight of chlorine or   about 1.0 to about 3.0% by weight of bromine.   3. The process of claim 1, wherein   characterized in that said isobutylene homopolymer possesses   a molecular weight of about 60,000 to about 80,000.   4. Process according to claim 1, characterized in that said ethylene-propylene polymer is a copolymer of ethylene, propylene and ethylidene norbornene. The process according to claim 1, characterized in that said layer comprises a crude polymer blend selected from the group consisting of (all parts being parts by weight) (a) a mixture of about 15 to about 30 parts of a linear low density polyethylene and from about 70 to about 85 parts of an elastomeric polymer, and (b) a mixture of about 20 parts of isotactic polypropylene and about 80 to about 85 parts of elastomeric polymer, said mixtures raw polymers also containing about 0.5 to about 20 parts by weight, per 100 parts of total polymer, of one or more fillers or pigments, said elastomeric polymer comprising about 50 to 100 parts by weight of an isobutylene-isoprene polymer and 0 to about 50 parts by weight of one or more polymers selected from (i) natural rubber and (ii) an isobutylene homopolymer having a weight of   molecular weight of about 50,000 to about 100,000.   The process according to claim 5, characterized in that said isobutylene-isoprene polymer is selected from (a) a copolymer containing from about 97 to about 99.5% by weight of isobutylene and from about 0.5 to about 3% by weight isoprene, having a Mooney viscosity (ML 1+ 8 at 100 C) of about 30 to about, and (b) a copolymer containing about 95 to about 99% by weight of isobutylene, about 0.5 to about 2 , 0% by weight of isoprene and about 0.5 to about 1.5% by weight   of chlorine or about 1.0 to about 3.0% by weight of bromine.   7. A process according to claim 1, characterized in that said stretching elongation is from about 75% to about 150%.   8. Process according to claim 5, characterized in that said elongation by stretching from about 75% to about 150%.   The method of claim 5, characterized in that said filler or pigment is selected from carbon black and titania, present in an amount of from about 5 to about 20 parts by weight. based on the total polymer.   10. Ribbon characterized in that it has insufficient adhesiveness to adhere itself to the relaxed state and being capable of fusion into a homogeneous mass when it is extended by at least about 50% and wound in superimposed layers said ribbon being formed of a crude polymer blend selected from the group consisting of (all parts being parts by weight) (a) a mixture of about 15 to about 30 parts linear low density polyethylene and about about 85 parts of elastomeric polymer, and (b) a mixture of about 15 to about 25 parts of isotactic polypropylene and about 75 to about 85 parts of elastomeric polymer, said elastomeric polymer comprising   about 50 to 100 parts by weight of an isobutylene polymer   isoprene and 0 to about 50 parts by weight of one or more polymers selected from (i) natural rubber, (ii) an isobutylene homopolymer having a molecular weight of about 50,000 to about 100,000, and (iii) a ethylene-propylene polymer containing about 50 to about % by weight of ethylene.   11. The tape of claim 10, wherein   characterized in that said isobutylene-isoprene polymer is selected from (a) a copolymer containing from about 97 to about 99.5% by weight of isobutylene and from about 0.5 to about 3% by weight of isoprene and (b) a copolymer containing about 95 to about 99% by weight of isobutylene, about 0.5 to about 2.0% by weight of isoprene and about 0.5 to about 1.5% by weight of chlorine or about 1.0 to about 3.0% by weight of bromine.   Tape according to claim 10, characterized in that said isobutylene homopolymer has a molecular weight of about 60,000 to about 80,000.   13. A tape according to claim 10, characterized in that said ethylene-propylene polymer is a copolymer of ethylene, propylene and ethylidene norbornene. 14. Tape according to claim 10,   characterized in that it is formed of a poly-   crude metal selected from the group consisting of (all parts being parts by weight) (a) a mixture of about 15 to about 30 parts of linear low density polyethylene and from about 70 to about 85 parts of elastomeric polymer, and b) a mixture of about 20 to about 25 parts of isotactic polypropylene and about 80 to about 85 parts of elastomeric polymer, said raw polymer also containing about 0.5 to about 20 parts by weight, per 100 parts of total polymer , one or more fillers or pigments, and the elastomeric polymer comprising about 50 to 100 parts by weight of an isobutylene-isoprene polymer and 0 to about 50 parts by weight of one or more polymers selected from (i) rubber and (ii) an isobutylene homopolymer having a molecular weight of about 50,000 about 100,000.   The tape of claim 14, characterized in that said filler or pigment is selected from carbon black and titanium dioxide present in an amount of from about 5 to about 20 parts   by weight based on the total polymer.   The tape of claim 14, characterized in that said isobutylene-isoprene polymer is selected from (a) a copolymer containing from about 97 to about 99.5% by weight of isobutylene and from about 0.5 to about 3% by weight of isoprene and (b) a copolymer containing from about 95 to about 99 percent by weight of isobutylene, from about 0.5 to about 2.0 percent by weight of isoprene and from about 0.5 to about 1.5 percent by weight of chlorine or about   1.0 to about 3.0% by weight of bromine.