DE2914562A1 - FLEXIBLE HOLLOW BODY - Google Patents

Description

DR.-ING. WALTER ABITZ DR. DIETER F. MORF DIPL.-PHYS. M. GRITSCHNEDEH

Patent attorneys

IG, April 1979 '

562

Postal address / Postal AddrQsQ * | [ P.O. Box 8601OS, 80OO Munich 86

Plenzenauerstraße 28

Telephone 983222

Telegrams: Chemindus Munich

Telex: (O) S23993

152/215 & 152/249

RAYCHEM CORPORATION

300 Constitution Drive, Menlo Park, California 94025, V.St.A.

Flexible hollow body

909842/0905

ORIGINAL INSPECTED

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-3-

The invention relates to shrinkable hollow bodies. Our French patent application 76/18236 describes shrinkable hollow bodies with a preferably made of elastomer material. "' :>} b ^ dividing inner part, that of an outer Clamping element is kept stretched radially, the inner part and the clamping element through each other a connection are held that can be broken, causing the inner part to shrink in the radial direction able. The tensioning element can preferably be peeled off from the inner part; peeling can be simplified, if you have a solution '" allows the agent to act. The tensioning element can be made of a fragile material that can stand through shatter a hard blow, e.g. made of hard PVC or another thermoplastic material. The clamping element but can also be provided with weakening points, for example with score lines, along which the Clamping element can be peeled off from the inner part, for example a metal tube with spirally notched or serrated indentation. Hollow bodies of this type are used to enclose splices and terminations electrical cables, e.g. pit cables, or other substrates.

In further development we have found that the usefulness of these items increases significantly leaves, if they could be modified in such a way that they are sufficiently flexible to accommodate the cross-section of the To deform hollow body without the inner part receding, while they remain the ability to do this Bring regression as needed. That way the expansion ratio would be that for the inner part is required if the article is to be used to wrap a substrate whose cross-section differs from

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that of the hollow body differs, reduced in size and thus the force / which must be exerted to maintain the deformation state, as well as the risk of the inner part being drained during would suffer "stress hardening" during storage (i.e. a non-traceable radial deformation). With the present invention such is modified Object forfeited.

On the one hand, the invention provides a flexible, shrinkable Hollow body with the following individual features:

(1) a hollow inner part which is made of elastomer material and is in a radially expanded state,

(2) a hollow outer tension member

(a) its inside with the outside of said Inner part is firmly connected and the said inner part in the radially expanded

^ withstands, said inner surface and said outer surface by a connection are held together, the peel strength of which is less than 50, preferably 4 to 30 lb per inch of linear width (pli) at 21 ° C (8.9, preferably 0.7 to 5.4 kg per cm of linear Width) is

(b) the outside of which is the outside of said hollow body, and

(c) which consists of a material which

(I) has a 2% secant modulus of 4000 to 120,000 psi (280 to 8400 kg / cm ² ) at 21 ° C,

(II) at 21 ° C a greatest elongation of at least 20% at a separation speed of

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200% per minute and a maximum of 150% at a cutting speed of 2000% each Minute has, and

(III) has such a notch sensitivity that the depth of the notch line is significantly increased can be if the clamping element has a score line in its outer surface, the depth of which is between 5% and 90% the thickness of the jig, and that the body is so twisted that a bending moment is exerted about the axis of such a score line.

In the subject matter of the invention, the outer surface of the tensioning element is generally provided with at least one score line, the depth of which is at least 5% of the thickness of the tensioning element. The expression "score line ¹¹ is intended here to denote an incision in the form of a line (this also includes a series of short incisions, i.e. holes that together form a line). As will be explained in more detail below, the depth of the score line is generally 5 to 90% of the thickness of the tensioning element, but the invention also includes articles in which at least a portion of the score line or lines completely cuts through the tensioning element Incision depth of the score line - to put at least part of the clamping element in a state that it can be peeled off from the inner part by hand (or with comparable effort), if necessary with the aid of a solvent acting on the connection. The term "solvent" is intended here denote any flowable medium that has the forces that the inner part connects with the clamping element, significantly reduces. Because the score line or the score lines

29U562

only need to be attached when the clamping element is to be removed, the invention also includes items on which initially no score lines are attached but on which score lines can be made which then allow the clamping element to be removed.

The invention also includes a method of covering of a substrate, consisting of the following process steps:

(1) Bending of an object of the type defined above, the outer surface of which has at least one score line has, the depth of which makes up 5% to 90% of the thickness of the tensioning element and thus bringing about a substantial increase in the depth of at least one such score line;

(2) enclosing attachment of the item to one Substrate, and

(3) Peeling off at least a part of the tensioning element from the inner part to restore the inner part

• - to initiate around the substrate, with the peeling .- is initiated by pulling off a section of the tensioning element from the inner part, which is located next to the aforementioned score line, the depth of which has been increased in process step (1).

Process step (1) is generally, but not necessarily, carried out before step (2). the Initiation of the peeling process by peeling off a section of the tensioning element generally takes place after Step (2) immediately before the inner part is caused to regress; but the introduction can also be before Step (2) take place provided that it does not cause premature regression of the inner part can.

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The invention also provides a method of manufacturing an object of the type indicated above; the manufacturing process includes the following steps:

(1) Stretching a hollow, made of an elastomer, body? I.

(2) Joining the outside of the radially expanded body with the inside of a tensioning element in order to establish a connection between the mentioned inner and outer surfaces produce whose peel strength is less than 50 pli (8.9 kg per cm of linear width at 21 ° C), and

(3) Notching the outside of said tensioning element to produce at least one notch line, its Depth is at least 5% of the thickness of the tensioning element,

wherein the clamping device consists of a material, (I) whose 2% secant modulus, greatest elongation and notch sensitivity correspond to the above values. ■ -. · ..

In the context of the description of the invention, reference is made to several physical properties. These properties are determined in the manner specified below.

Greatest stretch

is made at the specified temperature according to the procedure ASTM D412-75 using dumbbell specimens (Die D) and 1: inch (2.54 cm) markings are selected and the Cut speed 2 inches (5.1 cm) per minute for measurement at a cut rate of 200% per minute and 20 inches (51 cm) per minute for the measurement at one

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Separation speed of 2000% per minute.

2% secant modulus

is measured at the specified temperature according to the procedure in ASTH 0638-72 on a 0,!> Inch (1.25 cm) wide specimen at a crosshead speed of 0.5 inches (1.25 cm) per minute, a jaw separation of 5 inches (12.7 cm), and a chart speed of 20 inches (51 cm) per minute.

% Re eat deep

is carried out at 21 ° C using the notch sensitivity test given below certainly. A rectangular strip of the material is used as the test specimen; the dimensions are preferably:

1 inch (2.54 cm) wide and 0.075 (± 0.005) inch - 0.19 cm (i 0.013 cm) thick.

¹ with a razor blade, an incision is appropriate, the fold 0.2-about 0.1 to makes the strength of the specimen (ie, for example 0.008 inches (0.02 cm) in the preferred test specimen); the cut is made at right angles to the strip axis. Then, as indicated in * "Fig. 6, the strip is placed on a block with a right-angled edge with the cut directly above the block edge and bent by 90 ° over the block edge Material is enlarged along the bending line. Then the strip is divided into two parts by cutting through the remaining material along the bending line with a razor blade. With a suitable enlargement, the surface area of the treated edge, which is separated by the razor blade, can be clearly seen from the surface area The amount of damage caused by bending can be distinguished, and the mean depth can be measured

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ι no χ ^m3 - average depth of damaged surface area specimen thickness - depth of original cut.

To carry out the measurements described above, it is generally advisable to take test specimens from the material supply or from the material present in a suitable form. The measurements are to be made on material that has already received the shape of the clamping element, it should be possible at least for some measurements, Use specimens that are cut from the object after the inner part and the adhesive from the specimen are away. In other cases, the material must be determined and are test specimens from the material supply or to be made from material in a suitable form.

Peel strength

the connection between the inner part and the clamping element is determined at the specified temperature as follows: A rectangular pillar body free of score lines is cut from the article. The inner part becomes a little wider separated from the specimen by adding a solvent. After the solvent has evaporated the severed end of the core clamped in a jaw of an Instron tester, and the severed end of the Clamping element in the other jaw. The peel strength is measured at a jaw parting speed of 2 inches (5.1 cm) per minute, taking the mean of the highest and lowest values. For investigation the peel strength at 49 ° C, the test specimen is stored at 49 ° C and then placed in the box heated to 49 ° C Instron set; the entire arrangement has three minutes to equalize the temperature, and then the Peel strength determined.

The most appropriate test specimens would be 1 ZbIl (2.54 cm) wide. If you have test specimens of a suitable size from

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the item r.1.ch1: can cut off, or if examined should be whether objects in a satisfactory execution with a certain combination of inner part, Adhesive and clamping element can be produced, a peeling strength which is often practically equivalent can be achieved Achieve with a Piobek body that under the application of heat and pressure is produced as a laminate of the following structure

(a) an unstretched sheet of the elastomeric material that makes up the inner part consists,

(b) a layer of hot melt adhesive,

(c) a sheet of the material from which the stent is made.

The articles of the invention are generally "tubular" in shape. The subject of the invention, however, also includes end caps and other more complex hollow bodies expect at least one open end through which a substrate can be inserted. Furthermore, the invention Articles made up of one or more parts, which do not include an inner part of the type mentioned and a clamping element include, e.g. an object with a rigid tubular or T-shaped or Y-shaped central part and at least two end parts, each having an inner part and a clamping element of the specified type.

The objects according to the invention preferably have a circular cross-section; such objects are easiest to manufacture. But if the substrate to be covered has a non-circular cross-section, e.g. an oval pit cable, offers the use of a shrinkable body with a corresponding Cross-section has the advantage that the required expansion of the inner part is reduced. Shrinkable Bodies of non-circular cross-sectional configuration can be

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set by tnn the inner part and the clamping element with the desired cross-section and the inner part evenly against the clamping element at each other aligned cross-sectional areas.

The end result achieved with the invention is a substrate which is enclosed by the inner part after it has elastically moved back onto the substrate as soon as at least part of the tensioning element has been removed. The elastomeric material of the inner part is therefore in view on the final use, for example as electrical insulation. For objects to isolate We have achieved excellent results at splice points on pit cables by working with material approaches based on commercially available polychloroprene ("neoprene"). Other usable elastomer materials are described in U.S. Patent 4,070,746. Materials with low stress hardening are preferred. A part of the inside or the entire inside of the inner part can be coated with a material be that improves the seal and / or the adhesion of the part to the substrate, for example a mastic or a · self-adhesive adhesive, the strength of the inner part after its complete regression is normally in the range of 0.02 to 0.25 inches (0.51 to 0.6 cm), preferably between 0.05 and 0.15 inches (0.13 to 0.4 cm), however, greater thicknesses up to 0.5 inches (1.3 cm) may be useful in certain circumstances. To cover of electrical cables is generally worked with inner diameters of the inner part that between 0.1 and 3 inches (0.25 to 7.6 cm), preferably between 0.4 and 2 inches (1 to 5.1 cm) to full Regression, and between 0.125 and 4 inches (0.3 to 10 cm), preferably between 0.75 and 3 inches (1.9 and 7.6 cm) in stretched state. To cover other substrates, for example pipes and lines, the aforementioned or larger diameters are being worked?

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the expansion ratio of the inner part (i.e. aas ratio dos Durc.mer.ners when fully stretched the diameter in the fully recovered state) is usually between 1.3: 1 and 3: 1, preferably between 1.7: 1 and 2.3: 1. An increase in the strength or elongation of the core or module of the elastomer material leads to an increase in the retraction force of the inner part.

The inner part is usually attached to the clamping element by a layer of an adhesive, preferably a hot melt adhesive, tied together. Suitable adhesives are disclosed in U.S. Patent 4,070,746. The peel strength the connection at 21 ° C should be below 5O pli (8.9 kg / cm) lie. Since, on the one hand, the inner part does not separate from the clamping element under normal storage conditions may and on the other hand it must be possible, the peeling by peeling off a portion of the clamping element from the To make the inner part with manual force or a comparable effort, the peel strength should be the Connection at 21 ° C between 4 and 3O pli (0.7 and 5.4 kg / cm) in particular between 5 and 25 pli (0.9 and 4.5 kg / cm) but primarily between 7 and 15 pli (1.25 and 2.7 kg / cm). In order not to have to store temperature controlled, the peel strength at 49 ° C must be at least 2 pli (0.36 kg / cm), preferably at least 4 pli (0.7 kg / cm)

The clamping element must be so stable that it does not suffer any kinks that would preclude the use of the object, and This results in the requirement that the material of the clamping element at 21 ° C has a 2% secant modulus of at least 4000 psi (280 kg / cm), preferably at least 13,000 psi (910 kg / cm). On the other hand, the object must be so flexible that its cross-section can be made without applying undue force (and preferably by hand) is deformable, and it must be possible for peeling

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by pulling off the cine:. * section of the tensioning element from the inner part. These boundary conditions mean that the material has a 2% secant modulus of at most 120,000 psi (8400 kg / cm) at 21 ° C. Preferably the material has a 2% secant modulus at 21 ° C from 15,000 to 100,000 (1050 to 7000 kg / cm ² ), more preferably from 15,000 to 40,000 psi (1050 to 2800 kg / cm) for storage at controlled temperature To avoid za, the material will preferably have a 2% secant modulus of at least 4000 psi (280 kg / cm) at 49 ° C. The stronger the tensioning element and the lower the restoring force of the inner part, the lower the secant modulus of the material must be if satisfactory results are to be achieved.

The conditions for the greatest elongation at 21 ° C also depend on the peel strength of the tensioning element, because it is necessary that the portion which is peeled off to initiate peeling without cracking around one sufficiently large angle (about 90 to 180 °) must be able to be bent so that the tensile force can act, but that he should not be stretched excessively by the tear force. The greatest elongation at 21 ° C and a separation speed of 200% per minute is preferably at least 25%, in particular at least 35%, most preferably at least 50% and preferably does not exceed 120%, in particular 100%.

The last requirement on the material of the clamping element is that it has a sufficiently high notch sensitivity, so that by bending the object to apply a bending moment about the axis of the score line, its depth Makes up 5% to 90% of the thickness of the tensioning element, the depth of the score line can be increased considerably, preferably so that the depth of the score line is at least 50%, preferably at least 80% and in particular at least

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el · - ι> "njjff inn ill '■ ] · <* Λ ν' · \ <', ϊ. Worm aar, l <» inp iil * i dasi Iimoiii «' j 1 Ιπηππ.'π.! ί-ίκΙρ Lippr- hnnii'.ii we »writer below in detail * ji * zc2 j» _ j ι been ro]], J.nnn din I'oiblini.e by the Rpann ^ lpin '.' NL bii? In dnn Bn- -3 rich doj Lippo run in. Ucnn jodoeli, as on meiisi rrir- d'l InI ^1. ι I 'cjis «in' J ' ^s il dor I'eiblinie through an overlapping area dnr, ilpnniic.l emnnti ;, ie oiimn Ueidich, which is approaching on the Innantoi], is very careful that the Ti α ία of the gate line, especially in the overlapping area, does not increase by 90% d <= the thickness of the tensioning element There is no risk that the inner part will be damaged if the score line is manufactured wildly, but also from the point of view of shelf life. For reasons of manufacturing tolerances and shelf life, it is desirable to keep the score line only less than 75%, preferably less than 50% and preferably less than 25% of the thickness of the chip The thickness of the tensioning element below the score line should be at least 0.010 inches (0.025 cm), more preferably at least 0.020 inches (0.05 cm), and most preferably at least 0.040 inches (0.1 cm). The "% crack depth" mentioned above is a measure of the notch sensitivity of the material and is preferably at least 40%, most preferably at least 50%.

It has been found that when the 2% secant modulus at 21 ° C is below 40,000 psi (2800 kg / cm ² ), e.g. between 15,000 and 40,000 psi (1050 to 2800 kg / cm ² ), the values of the 2% secant modulus (S), the greatest elongation at 21 ° C (E), the% depth of tear (T) and the peel strength at 21 ° C (P) have such amounts that the relationship

T - 0.002 S + 0.054 E + 0.54 P.

(where S is expressed in psi and P is expressed in pli) (or the relationship T - 0.00014 S + O, O54 E + 0.096 P,

2
where S is expressed in kg / cm and P in kg per cm)

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BATH ORIGINAL

■ /! .; ...; iise im, t..u \ kr 'ir-chen lO irnti iO, on the beaten between 15 and .15 anniiumt.

The material for the clamping element is to be selected with regard to the specified requirements, including of course the requirement that the material must bond well with the adhesive. An organic polymer is preferably suitable as the material. Synthetic organic polymers are preferred, but materials based on natural or modified natural polymers can also be used, e.g. B. of cellulose polymers and polymeric Mischderivateii of unsaturated oils. Suitable materials can be a mixture of at least two polymers that differ significantly in terms of modulus, elongation or ability to bond with the adhesive or two or all of the parameters. The material can, for example, be a mixture of two polymers, one of which has a relatively high modulus (e.g. over 5000 psi (350 kg / cm) / preferably over 7000 psi (490 kg / cm) and / or a relatively low elongation (e.g. below 100%, preferably below 50 I) and the other polymer has a relatively low * modulus (e.g. below 5000 psi - 350 kg / cm) and V or relatively high elongation (e.g. greater than 100%, preferably greater than 150%), wherein the weight ratio of the first to the second polymer is generally between 1.5: 1 and 4: 1, preferably between 2: 1 and 3: 1. If the adhesive is a polar material, as is usually the case if a polar material Rubber, for example a polychloroprene, is used for the inner part, at least one of the polymers is generally a polymeric polymer If the adhesive is non-polar, the material of the tensioning element will normally also be non-polar, or at least at least t have a larger proportion by weight (based on the polymer materials) of non-polar polymer. With suitable polymer

- ι ~ \ -
4 2/090 5.

2ί) ΙΑ

mixes 5; 1 η. ... mc. ·: cm I; ι uokminchpolymeren in ι 1. Polyesterblock.'j and iolyäth-irblock. · ;, for example a polytetramethylene ether / polytetramethylene terephthalate block mixed polymer provided (eg "Hytrel" or "Dyvax", polymer "which" is distributed by DuPont be) and a copolymer MLT low modulus of at least Asten an olefin, particularly ethylene, and at least one polymeric copolymer, in particular a Vinylester a carboxylic acid Alky!, including Vinylaceteit, or a Alkylenter dt> r acrylic or methacrylic acid, for example Xthylacrylat. A particularly useful polymer mixture is a mixture of :; Polyvinyl chloride and a rubbery chlorinated polyethylene. The material can also have at least one component that increases the notch sensitivity of the material. For example, there may be in the batch: an appropriate part, e.g. 25 to 75%, preferably between ^r > () and 65% (wt.%) Of a certain filler, usually a non-reinforcing filler, e.g. an inorganic filler such as calcium carbonate, amorphous silicon dioxide or a silicate such as clay. In general, the greater the amount of such fillers, the lower the strength of the bond between the material and the hot melt adhesive. Alternatively or additionally, a component with a low molecular weight and poor compatibility, for example wax or plasticizer, can be included in the batch, as a result of which the peel strength between the material and hotmelt adhesives is reduced. The material can and often will contain other ingredients including, for example, antioxidants, fire retardants, pigments and extrusion aids.

The material for the tensioning element is preferably around thermoplastic material so that it can be given the required shape by melt forming, in particular, it can be melt-extruded as a tube and

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BATH ORIGINAL

£ -. (. Ιι] J f'ssßnd to the g. V / firi; - <, *! 11ru!, ', Ine , im ', lKjcncliiniiini wci don. The 'material can be networked i;' dn to aui serve, the required Eigenschai t get .shoinbination "

It is true that -Ίηγ -Λ aiii. That the Iimenteil is expanded radially, but it should be noted that the manufacturing process-the inner part generally axially and radially acting restoring forces. This fact hai; practical meaning because it never means that the back-bending forces of the inner part tries to pull this part off the tensioning element on the limbs. This requires a higher bond strength so that the article does not regress prematurely, and it is often necessary to insert plugs into the article for storage so that the end portions of the inner part remain free of coating compound, especially if the peel strength is below 4 pli (0.7 kg / cm).

The course of the score lines on the object can be very different. In any event, there should be at least one score line to at least one end of the article so that peeling can begin at the end of the article. In this case in particular, the tensioning element is preferably longer than the inner part and is connected to the inner part in such a way that a lip protrudes at one end, preferably at both ends of the object. The formation of such a lip is very advantageous because such a part of the clamping element can easily be gripped by the user with the hand or with a suitable tool in order to start peeling off the clamping element from the inner part. The lip is preferably at least 0.25 inches (0.6 cm) long, for example 0.5 to 1.0 inches (1.3 to 2.5 cm) long. However, the score line or the score lines do not necessarily have to extend to the edge of the clamping element , provided that they are after

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BATH ORIGINAL

29 Ί 4 562

they broke open ίύικί. i-vluen Bor ei oh present that can be pulled off the clamping element. In this case in particular, the area at which the peeling is initiated preferably has a protrusion at which one can attack and begin the peeling.

In one embodiment, a plurality of parallel straight score lines extend from one end of the article to the other, the spacing between the score lines being, for example, 0.2 to 1 inch (0.5 to 2.5 cm), preferably 0.4 up to 0.75 inches (1 to 1.9 cm). Such score lines are provided, the clamping element can be without Vei / ending peel off a solvent in the form of strips, äusserstenfalls some solvent is at the initial position to open the connection needed. In an embodiment that works on the same principle, at least one score line is guided around the object in a helical manner. Furthermore, it is possible to restrict the score line or the score lines to a limited area which can be at one of the ends of the article or at both ends or in the area between the ends, and the score lines then do not serve to peel off the whole To allow clamping elements from the inner part; Rather, it should only be possible to lift off part of the clamping element and thereby create a penetration opening for solvent, from which the solvent can continue to act along the connecting surface, so that the peeling takes place primarily through the forces causing the elastic regression that the inner part pull away from the weakened joint. It has been found that the regression of the inner part proceeds surprisingly quickly in this way, especially when the object is arranged so that the solvent can run down through the connecting surface and the object is kneaded during this process so that the solvent dissolves more quickly can spread. When the inner part has receded,

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the i <p: umö should generally learn t whenever possible be removed, d .. making sure that the inner part will not be damaged. The notch sensitivity of the clamping element can be used successfully, because you need me tall> long ?; the outside of the clamping element notch, which can then be broken open and removed.

The score lines can be created by using a sharp blade cut into the surface of the clamping element is before or after the inner part is glued to the clamping element; the score lines can also be used in the At the time of manufacture of the clamping element, i.e. when extruding or pressing the element.

The score lines can be broken up by bending the object at will, provided that there is a bending moment around the Axis of the score line is exerted, for example by breaking the item. True, it is recommended to all Breaking score lines, however, isn't necessarily required, provided that it is only broken open to such an extent that the peeling takes place well.

The objects according to the invention and their manner of use are drawn in Figures 1 to 5 and 7 to 9.

Fig. 1 shows an object according to the invention with an inner part 1, which by an adhesive layer 3 with a Tensioning element 2 is connected and provided with a mastic layer 4 on the inside. Score lines 21 run from one end of the tensioning element 2 to the other; their depth makes up about 20% of the thickness of the tensioning element 2. That Clamping element 2 is longer than the inner part 1 and forms a lip 22 at the left end. Preferably is on the right At the end a similar lip is formed, but the inner

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BATH ORIGINAL

On the unde .: ι, ^l ! nd part 1 can also be as long as the clamping element 2.

Fig. 2 shows a terminator 7 with a frustoconical section 8 _f whose diameter and taper are chosen so that an end piece of the type shown can be inserted into each end of the recoverable object for storage so that the inner part is kept away from the skin.

In Fig. 3, the object of Fig. 1 is drawn, which has been printed so that the score lines 21 through have continued through the tensioning element 2 and have become columns 21A; then is the clamping element has been pushed over a substrate 5 with an oval cross-section. A squeeze bottle 6 becomes solvent 61 in the area the lip 22 is sprayed onto the adhesive layer 3. The regression of the inner part 1 is then initiated in that adjacent strips of the clamping element 2 between the break lines 21A are peeled off, adding solvent to the adhesive as desired or necessary layer is sprayed in the peeling area. FIGS. 4A to 4E show cross sections through a central region of FIG Arrangement lying point again when removing the strips. In order not to obscure the drawings, are the adhesive layer 3 and the mastic layer 4 are not shown in FIGS. 4A to 4E.

In FIG. 5, a further object according to the invention is shown, which is comparable to the object according to FIG. 1 is, but has only a single score line that runs helically around the tensioning element.

FIG. 7 shows a further object according to the invention, which is also comparable with the object according to FIG. 1

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BATH ORIGINAL

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but has two short Kcub lines, one Define tear strips that help create an area serves, which serves as a reservoir for solvent that enters the interface between the inner part and the Clamping element is introduced (see. Fig. 8) and between the inner part and ckia clamping element seeped through.

Fig. 9 gives another subject matter according to the invention again; here two score lines 21 running in the circumferential direction are provided in the center of the object and a V-shaped score line 21 * between the score lines 21. The tear strip 23 is at the open end of the V-shaped score lines 21 'between the score lines 21 on the tensioning element 2 molded or otherwise connected to it. After the score lines 21 and 21 'have been broken, the tear strip 23 is peeled off to the outside and around the object, so that the bounded by the lines 21 Peeling off the strip from the stent; Solvent can be used to aid the process as required will. Then the solvent is applied to the exposed connection line on the edges of the exposed section given of the inner part; from there it seeps between the inner part and the clamping element. · · * -

The present invention is also an improved one Process for the production of a recoverable hollow body has been developed, which on the one hand has a hollow inner part has, which consists of elastomer material and elastically stretched radially over its natural dimensions is, and on the other hand, a hollow outer clamping element, the inside of which with the outside of said Inner part is connected by a layer of hot melt adhesive and that said inner part in said holds radially stretched states, in particular one flexible, shrinkable hollow body of the above Kind; the procedure consists of the following individual steps

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BATH ORIGINAL

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zuainiTi 'j;

(1) Make an assembly from a hollow stent with a heated one located inside the clamping element but not touching the clamping element, Hollow iris part made of elastomer material with a coating of hot melt adhesive on the outside of the inner part, with the hot melt adhesive being bonded to one above it Temperature is located;

(2) expose the hollow part in the radial direction to stretching forces so that the hot-melt adhesive touches the inside of said clamping element, the conditions being chosen so that the pressure between the hollow part and the clamping element is between P ^ and P ₂ , where P ^ also denotes the pressure that can be generated by increasing the radius of the clamping element by expanding the hollow part by 5%, and P ₂ the maximum pressure that can be generated by expanding the radius of the clamping element by expanding the hollow part within the elastic limit of the outside of the tensioning element is increased;

(3) cooling the assembly to cool the hot melt adhesive below its bonding temperature, and

(4) Eliminate the expansion forces.

In a preferred embodiment of the method, the tensioning element is released (i.e. without any external boundary, e.g. in air) stretched by an amount between 5% and the value at which the outside of the Tensioning element experiences an expansion below the elastic limit. However, the same pressure can be used in any way on the connecting line between the tensioning element and the inner part. For example, the

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29U562

Span. ¹ '- "IeDf- ei ^ o iiaimauL- ^: ung, against which the element is pressed by the expansion forces.

The tensioning element preferably consists of an organic polymer, the properties of which are limited to those of the tensioning element McissG eiiio elastic radial expansion of, for example, at least 5% at 21 ° C. If it is on the other hand is too elastic, it cannot be used to close the inner sleeve in a radially stretched position keep. The elastic limit of the material at 21 ° C. is preferably between 5% and 60%, in particular between 15% and 50% and best between 15% and 40%. It is important to check the elastic limit of the outside of the Clamping element not to be exceeded during the process. If, therefore, as provided, the tensioning element is in the process is stretched, its elongation is preferably at most 80% of the elongation at the elastic limit 21 ° C and preferably 10 to 75% of the elongation at the elastic limit at 21 ° C. With preferred constraining forces, the expansion ratio is 1.05 to 1.4, in particular 1.05 to 1.20.

Above, the elastic limit of the outside of the tensioning element is referred to. Especially when the tension element, as is preferred, as such, made of thermoplastic material consists _r takes the elastic limit of the material temperature rises rapidly. Of course, it cannot be avoided that the interior of the tensioning element is heated by heat transfer from the inner part and the adhesive, and as a result the interior of the tensioning element suffers plastic deformations. In order to avoid plastic deformation of the outside of the tensioning element, effective steps can be taken to cool the outside of the tensioning element during the entire stretching process, while maintaining a satisfactory temperature.

9098 / ₊ 2/0905

BATH ORIGINAL

29U562

tur control can u .. generally achieve by the arrangement is stretched in air and, as soon as the stretching is complete, quenched, e.g. by immersion in a water bath or other liquid.

The inside of the clamping element also expediently carries a layer of the hot melt adhesive, because this improves the adhesion between the inner part and the clamping element.

The stretching forces that are used to stretch the inner part can be provided in any way e.g. in the form of an expandable mandrel or as hydraulic means.

The invention is illustrated by the following examples in which parts, ratios and percentages are by weight are yet to be clarified.

example 1 Process step A

The substances listed in Table A are mixed in a Banbury internal mixer.

Table A substance

Polychloroprene (Neoprene TRT) Antioxidant (Algerite Stalite S) Magnesium Oxide (Maglite D) Soot (Vulcan 2)

Aluminum trihydrate (Hydral 705) silicon dioxide (HiSiI 233) antimony trioxide
Stearic acid
Plasticizer (Flexol TOF)

909842/0 9 OS

BATH ORIGINAL

Continuation of Table A

Substance parts

ZnO (Kadox 15) 5

Hardener (Thiate E) 0.75

Hardener (Epon 828) 1

The mixture became an elastomer tube about 0.125 inch (0.32 cm) at about 175 ° C for about 10 minutes Thickness, 0.75 in. (1.9 cm) inside diameter and approximately

17 in. (43 cm) length (tube A) pressed.

Process step B

The ingredients listed in Table B were in one Banbury indoor mixers mixed.

Table B Substance Parts

Block copolymer of polytetramethylene ether and polyethylene terephthalate (Hytrel 4056) 70

Ethylene / vinyl acetate (18%) - mixed polymer (Alathon 3170) 30

Antioxidant (Irganox 1010) 0.1

Chalk filler (Vicron 15-15) 125 dye (Wilson 50-OR-18) 2.5

The mixture became a tube about 0.085-0.005 inches (0.22-0.01 cm) thick, approximately 1.5-0.020 in. (3.8 ± 0.05 cm) inside diameter extruded and cut into pieces of approx

18 in. (45.7 cm) cut (tube B).

Process step C

The outside of the pipe A was provided with a coating containing a 1% solution of a 60/40 mixture of Hytrel 4056 and Dyvax 772 in methylene chloride.

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Ö098U / 0905

-3 ** 29U562

The inside of the tube B was ground out by the pipe was passed over a rotating grinding wheel, and was then provided with a coating comprising a 10% solution of a 60/40 mixture of Hytrel 4056 and Dyvax 772 in methylene chloride. (Dyvax 772 is a block copolymer that is essentially made with Hytrel 4056 but has a lower melting point). After all of the methylene chloride has evaporated, the tube A was heated to about 165 ° C and immediately placed on a mandrel. The unheated tube B was immediately placed symmetrically over tube A. Then the mandrel was stretched until the tube A made initial contact with it the tube B received, and then the tube B was stretched by 5 to 10%. Then the entire The arrangement is immersed in cold water at about 20 ° C for about 4 minutes. After the arrangement is taken out of the water the mandrel was contracted and removed from the pipe. Tube A and Tube B contracted until the Tube B was roughly in its original shape again.

Process step D

Longitudinal and parallel score lines about 0.008 inches (0.02 cm) deep and about 0.5 inches (1.2 cm) mutual spacing were created with a razor blade on the outside of tube B; the score lines ran, as drawn in Fig. 1, from one end of the tube to the other.

Step E

The article made by this process was stored until use with the end plug were inserted so that the pipe did not return to its old shape prematurely. Before using the item the terminations were removed and the object

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909842/0905

-33 _V 29U562

eg pressed between the hands of the user or between the foot and the floor so that the score lines open. Then the item was pushed over one of two pit cables to be spliced together. The cables have been spliced and the object placed around the splice. At one end of the object, a suitable solvent, ie a fluid which considerably weakens the adhesive bond, which can but does not have to be a solvent for the adhesive, for example 1,1,1-trichloroethane, was placed on the glue line. The user grasped tube B where the solvent was applied and pulled the tube away from the splice. Tube B tore along the adjacent score lines so that a longitudinal strip of tube B could be peeled off? Additional solvent was added to aid the peeling process. Further strips were then peeled from tube B in the same manner until tube A had completely regressed and tube B was completely removed.

Example 2 Process steps A, B and C

To make an article with the stretched tube A attached to the tube B, the process steps were followed A, B and C according to Example 1 repeated.

Process step D

Two parallel score lines about 0.5 inches (1.3 cm) apart and each about 1 inch (2.5 cm) long, one end of the article was pulled with a razor blade (see Figure 7). The score lines were approximately 0.050 inches (0.1 cm) deep.

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909842/0905

Step E

The article so far prefabricated was stored pending use, and plugs were inserted with it the tube A could not regress. Before using the object, remove the stoppers, and the end of the object in which the score lines were cut received a blow around the score lines to pop open. Then the object was connected to one of the two pit cables to be spliced together pushed. The cables were spliced and the article was placed around the splice. Then the spliced ones were The cable and the object are placed in such a way that the object is at an angle of 15 to 30 ° from the horizontal was inclined; the score lines pointed upwards. On the connecting line in the area of the score lines was a Solvent and the area of tube B delimited by the score lines was grasped and removed from the Splice peeled off to form a pocket in which more solvent was added. The solvent penetrated between tube A and tube B, and the user kneaded the object between his hands. To The penetrating solvent had softened the connection between pipes A and B for about 1.5 to 2.5 minutes. that the Kohr A was able to detach from the tube B, so that it regresses and around the splice could lay. Then the tube was notched from end to end with a razor blade or knife; the Score line was broken by pushing the tube along the score line and the tube by hand or with a Knife torn off.

The objects produced according to process steps A to D of Examples 1 and 2 showed the following properties:

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909842/0905

Tensile stress at 100%

Elongation of pipe A 175 to 250 psi (12.2-17.5 kg / cm)

Peel strength of the joint between the 7 to 12 pli (1.25-2.14 kg / cm) Pipes A and B

2% secant modulus of the

Tube B at 21 ° C 20,000 psi (1400 kg / cm ² )

Extreme elongation of the

Pipe B at 21 ° C 79 to 85%

% Crack depth for pipe B 50 to 60%.

Example 3

The procedure of Example 1 was repeated, except that tube A consisted of those in Table C below specified substances.

Table C Substance Parts

Polychloroprene (Neoprene GW) 100

-Magnesium Oxide (Maglite D) 1 * 5.

Silica (Hi SiI 233) 35

Silicon alkyl A189 0.5

Stearic acid 0.6

Antioxidant (Octamine) 1.3

Antioxidant (Agerite DPPD) 0.7

Soot (Thermax) 5

Polyethylene Oxide Glycol (Garbowax 4000) 3

Tricresyl phosphate (plasticizer) 12.5

ZnO (Kadox 15) 5

- 27 909842 / G905

Claims (1)

Claims 1. Flexible hollow body, consisting of (1) a hollow inner part, which is made of elastomeric material and which is in a radially expanded state located, and (2) a hollow outer tensioning element, the inside of which is on the outside of the named inner part is attached and that holds said inner part in the radially expanded state and its outside forms the outside of the said object, characterized in that the inner part (1) and the outer clamping element (2) are firmly connected to one another are by a compound (3) whose adhesive strength at 21 ° C is lower than 8.9 kg / cm, and that the Clamping element (2) consists of a material that (I) a 2% edgeband modulus of 280 to 8400 kg / cm at 21 ° C, (II) an extreme elongation at 21 ° C of at least 20% with a cutting speed of 200% per minute and a maximum of 150% with a cutting 909842/0905 speed of 2000% per minute, and (III) has a notch sensitivity such that the Depth of the score line (21) if the clamping element (2) has a score line (21) on its outside has ,, the depth of which makes up 5 to 90% of the thickness of the clamping element, by turning the Object in the sense that a bending moment occurs around the axis of the score line, significant can be enlarged. 2. Object according to claim 1, characterized in that the outside of the clamping element (2) with at least a score line (21) is provided, the depth of which is 5 to 90% of the thickness of the tensioning element (2). 3. Article according to claim 1 or 2, characterized in that the clamping element (2) consists of a material whose 2% secant modulus at 21 ° C 1050 to. 7000 kg / cm, the extreme elongation of which at 21 ° C is 35 to 120% at a cutting speed of 200% per minute and the% tear depth of which is at least 40%. 4. The object of claim 3, characterized in that the clamping element consists of a material whose 2% Secant modulus at 21 ° C 1050 to 2800 kg / cm, its extreme elongation at 21 ° C 50 to 100% at a separation speed of 200% per minute and its% crack depth is at least 50%. 5. Article according to one of the preceding claims, characterized in that the adhesive strength of the connection (3) between the inner part (1) and the clamping element 9098 4 2/0905 29H562 ment (2) at 21 ° C 5 to 25 pli (0.9 to 2.7 kg / cm) amounts to. Object according to one of the preceding claims, characterized in that the numerical value of the link T - 0.00014 S + 0.054 E + 0.096 P (where T is the% crack depth, S is the 2% secant modulus at 21 ° C in kg / cm ² and lower than 2800 kg / cm ² , E is the extreme elongation at 21 ° C and P is the adhesive strength at 21 ° C in kg / cm) is 10 to 60. 7. The object of claim 6, characterized in that the numerical value of the member is 15 to 35. 8. Object according to one of the preceding claims, characterized in that the clamping element (2) from a material composed of a mixture of a first polymer with a modulus greater than 490 kg / cm and a second polymer is constructed with a module below 350 kg / cm, the weight ratio between the first and second polymer is between 1.5: 1 and 4: 1 and in the mixture up to 75% by weight of the batch consist of a special filler. Object according to one of the preceding claims, characterized in that the adhesive strength of the connection between the inner part (1) and the tensioning element (2) at 49 ° C is at least 0.7 kg / cm and the tensioning element (2) consists of a material whose 2% secant modulus at 49 ° C is at least 280 kg / cm ² . 9098 42/0905 10. The article of claim 1, characterized gekenireeicfmet that the inner part (1) rait>.;. em clamping element (2) through a Layer (3) of hot melt adhesive is connected, which creates a bond between them, their adhesive strength at 21 ° C between 0.7 and 5.4 kg / cm and at 49 ° C is at least 0.7 kg / cm that the Outside of the clamping element (2) is provided with at least one score line (21), the depth of which is 5 to 75% the thickness of the tensioning element (2), and that the tensioning element (2) is made of a material which (I) contains an organic polymer, (II) a 2% secant modulus of 1050 to 7000 kg / cm at 21 ° C and at least 28O kg / cm ² at 49 ° C, (III) an extreme elongation at 21 ° C. of 35 to 120% at a separation speed of 200% per minute has, and (IV). has a% crack depth of at least 40%. 11. Tubular object according to one of the preceding Claims, characterized in that the clamping element '(2) is longer than the inner part (1) and at least one End (22) of the clamping element (2) forms a protruding lip at one end of the article, and that the The outside of the tensioning element (2) is provided with at least one longitudinal score line (21A) which extends from one end of the tensioning element (2) to the other. 12. The method for encasing a substrate, characterized by the following steps: (Ä) twisting one of the preceding claims defined object, in which the outside of the clamping element (2) with at least one score line (21) is provided, the depth of which is 5 to 90% of the thickness of the tensioning element (2), so that the 909-84 2- / 0 9 05 29U562 Depth of at least one score line is increased noticeably and thereby at least one section the tensioning element (2) arises, which can be clipped to the inner part (1); (B) place the object around the substrate and (C) Peeling off at least a part of the clamping element (2) from the inner part (1) so that it can recede, the peeling being caused by the peeling a section of the tensioning element (2) is introduced next to a score line (21), the depth of which in the process step (A) had been enlarged. 13. The method according to claim 12, characterized in that the solvent at the connection (3) between the inner part (1) and the clamping element (2) during the process step (C) is supplied. 14. The method according to claim 12 or 13, characterized in that the process step (A) before the process step (B) is executed. 15. A method for producing a receding hollow body, which consists of (I) a hollow inner part (1), which is formed from an elastomer material and of its natural dimensions from is elastically stretched in the radial direction, and (II) a hollow outer Clamping element (2), the inside of which is attached to the outside of the inner part (1) by means of a layer (3) of hot melt adhesive is attached so that the inner part (1) maintains its radially expanded state, which method is characterized by "that 9 0 9 8 4 2 / 00Q5 29H562 (1) A structure is prepared which is a hollow stent (2) and in this, but not touching it, a heated hollow inner part (1) Elastomer material and with a coating (3) of hot-melt adhesive on the outside of the inner part, wherein the hot melt adhesive is heated above its bonding temperature; (2) the hollow inner part (1) is subjected to radial expansion forces in such a way that the hotmelt adhesive layer (3) touches the inside of the clamping element (2), with between the hollow inner part (1) and df-m clamping element (2) a pressure lying between P ^ and Pj is exerted, with P ^ being the pressure that can be exerted by increasing the radius of the clamping element (2) by expanding the inner part (1 ) is increased by 5%, and P _{2 is} the highest pressure that can be generated by increasing the radius of the clamping element (2) by expanding the hollow inner part (1) within the elastic limit of the outside of the clamping element (2), (3) the assembly is cooled to cool the hot melt adhesive below its "bonding temperature"; and (4) the stretching forces are removed. 16. The method according to claim 15, characterized in that the clamping element (2) is stretched freely by an amount between 5% and such an amount that the outside of the clamping element is 10 to 75% of that at 21 ° C at the elastic limit existing elongation is stretched. 17 »Method according to claim 15 or 16, characterized in that the expansion ratio of the tensioning element 909842/0905 29U562 (2) 1.05 to 1.20, and that the tensioner consists of thermoplastic polymer material, the elastic limit of which at 21 ° C is 5 to 60%. SQ98 ⁷ £ 2 / 09Q5