DE2714534A1 - Vulcanised poly:norbornene roller cage for sealing socket tubes - contains high proportion of filler and plasticiser - Google Patents

Abstract

Rubber roller cage for sealing socket tubes consists of vulcanised polynorbornene, highly filled with inert filler and plasticiser. Shore A hardness can be set to 15-35. Tensile strength can reach >10 N/mm2. Residual deformation is 20% after 24 hrs. at 70 degrees C. Wt. ratio filler: polynorbornene is >1, and wt. ratio plasticiser: polynorbornene is esp. 2:1 to 4:1. The plasticiser may be a naphthenic mineral oil. Fillers include chalk, kaolin, C black.

Description

Rolling ring for sealing socket pipes

The invention relates to a rubber rolling ring for sealing Socket pipes.

For the sealing of socket pipes, rolling rings are known which are can essentially be divided into two groups0 The first group comprises the massive rings with different cross-sections which can also have a bore. The hole serves to increase the flexibility and deformability of the ring, to prevent the ring socket from bursting if the ring dimensions are in the upper tolerance zone lie. The second group of rolling rings consists of porous rubber material.

They are much easier to roll up and avoid even with large ones Tolerance jumps the bursting of the pipe socket 0 However, these hinge have the disadvantage that their manufacture is more difficult. Another disadvantage is that such cellular Rings are more easily damaged and then lead to leakage because of their strength is far below that of solid rings. The object of the invention is to provide a rolling ring to create the excellent mechanical values of a solid rolling ring, such as they are required in DIN 4060, with the easy deformability and the soft Spring characteristics of a rolling ring made of cellular material combined, surprisingly it was found that polynorbornene with high proportions of inactive fillers and Plasticizer oils solve this problem0 The Shore hardness can be between 15 and 35 to adjust. With a suitable mix structure, not only a low tear strength is achieved of more than 10 N / mm2 is achieved, but the remaining requirements are also met DIN 4060 with regard to restoring stress, restoring force and compression set (maximum 20% after 24 hours

at 700C) fully met0 The fulfillment of these demands but is essential for the performance characteristics of a holring0 you demand a rubber-elastic material with a high degree of cross-linking. All the more surprising was that polynorbornene, which has a freezing temperature of + 37 ° C and only Gaining a rubber-like character due to the addition of plasticizers, even at high levels Degree of filling corresponds to these requirements 0 To soften the polynorbornene 100 - 400 TleO mineral oil plasticizers are preferred (for every 100 parts of polymer) naphthenic type. In addition, 100-250 Tle. Filler such as chalk, Kaolins, thermal soot added. The networking systems meet the requirements of the Fer Zngsververfahren and the end product adapted in a common way. You insist from sulfur (0.5-4 parts), sulfenamide accelerator (1-7.5 parts), if necessary Additional accelerators, e.g. tetramethylthiuram disulfide (0.2 parts) and zinc oxide and stearic acid in the usual amount.

The mixtures are produced in a manner known per se by means of internal mixer and rolling mill The Hollringe can both by vulcanization be produced in compression molds as well as by injection molding.

Since the soft polynorbornene mixtures are easy to extrude, can First a profile strand with the desired cross-section must be extruded0 This can continuously in the salt bath or ultra high frequency vulcanization process or are vulcanized discontinuously in steam autoclaves. The vulcanized strands are then cut to length and then glued or vulcanized together made endless.

The invention is illustrated in one figure and in the following Example Example described is a mixture of commercially available polynorbornene constructed as follows: Polynorbornene 100 parts, naphthenic plasticizer oil, 250 parts Chalk 120 parts FEFX carbon black 5 parts stearic acid 1 part antiozonant wax 5 parts antiozonant JPPD 1.5 parts zinc oxide 5 parts benzthiazyl-2-sulfenmorpholide 5 parts tetramethylthiuram disulfide 0.3 parts sulfur 2 parts The mixture of these ingredients was made according to the preceding Verbatchen part of the plasticizer oil with the polymer in the usual way Internal mixers made from this were heated to 155 in 20 minutes 0C rolling rings with 12 mm ~ manufactured, their test according to DIN 4060 the following values resulted in requirements according to DIN 4060 property unit dense cellular mixture structure Example hardness Shore A Shore - - 25 Tensile strength N / mm2 10 2 10.9 Elongation at break % at least 350 at least 350 530 Compression set% max. 20 no 24 hours 70 C chemical resistance n07 days (volume increase) at pH value 2, ~ max. + 5 marx, + 5 +4 at ~ 12% 2 max. + 5 max. + 5 +0.5 restoring stress N / mm at least 00.15 at least 00.2 0.22 at 25% deformation. 15 minutes.

Restoring force (under 30 mm ring) b. Maximum deformation for clay pipes kN / m max. 50 max. 50 15 Round cords of 20 mm # were made from the same mixture injected, which were vulcanized in steam at 4.3 atmospheres for 30 minutes and the same Test values resulted

Claims (1)

A n p r ü c h e 1. Rolling ring made of rubber for sealing bluff pipes, characterized in that the rolling ring is made from highly filled with filler and plasticizer vulcanized polynorbornene consists0 2.) Rolling ring according to claim 1, characterized in that that the proportion of Ftilistoff is higher than the proportion of polynorbornene. 30) rolling ring according to claim 1, characterized in that the iseichmacherabschnitt is 2-4 times higher than the proportion of polynorbornene.