DE4340902A1 - Rubber compsns. based on epoxidised natural rubber and viscosity stabilised natural rubber - have low dynamic stiffening and high damping - Google Patents

Abstract

The cpds. are based on a natural rubber component comprising 45-70 wt.% epoxidised natural rubber and 10-25 wt.% viscosity stabilised natural rubber together with conventional ingredients such as fillers, plasticisers, anti-ageing agents, crosslinking agents, ZnO, and other additives. Pref. in the epoxidised natural rubber ca. 50% of the double bonds are epoxidised. USE/ADVANTAGE - The compsns. are esp. useful for making moulded rubber articles and composite articles of rubber and metal and/or plastics, esp. for rubber springs and couplings such as machine mountings for marine equipment to reduce vibration in ships. The compsns. give moulded rubber bodies with low dynamic stiffening and high damping performance.

Description

Rubber mixture for the manufacture of rubber products with low dynamic stiffening and high damping based on natural rubber as well as usual Mixing ingredients, such as fillers, plasticizers, Anti-aging agents, cross-linking agents, zinc oxide as well optionally other additives.

Two rubber springs or rubber couplings of the same geometry, Dimensions and Shore A hardness, but made of rubber compounds different recipe design, can only with slightly different static Properties significantly different have dynamic properties. These two Show rubber mixtures or their vulcanizates a different dynamic stiffening.

From an application point of view, rubber springs, Rubber couplings and other rubber products with low dynamic stiffening advantageous. Such Springs and clutches lead - a low static Stiffness (e.g. due to a lower Shore A hardness) provided - for vibration systems with low Natural frequencies and often enable sufficient ones or even good vibration isolation even at low or average excitation frequencies (operating pressure numbers).

Such conditions are often found in drive systems from Ships ahead and require such rubber springs for that elastic mounting of the main machines or such Rubber couplings in the torsional vibration systems.  

Dynamically low stiffening rubber springs and rubber clutches lead to low reaction forces / Reaction moments and are also for this reason Cheap.

Rubber springs or rubber couplings with high damping reduce those when driving through resonance states occurring vibrations considerably and so cause a reduction in the vibration stress on the machine, of the device or system. The heating of such feathers or couplings is less than the heating of springs or couplings with low damping because of the heating in an almost square connection to the swing path amplitude stands.

Such springs are also suitable for passive insulation, because usually low system frequencies and high Cushions are required.

Soft springs and are usually used for shock insulation additional dampers required. If rubber springs are possible are those with low stiffness / low dynamic stiffening and high damping preferably.

When making a rubber compound Different types of elastomers must be compatible be considered in the polymer waste. Will Vulcanizate properties required by none Elastomer can be met alone so it is important that a thermodynamically compatible polymer blend is available that optimally meets all required properties owns. Such a polymer blend must also be used be networkable.  

The rubber mixture according to the invention of claim 1 now enables the production of Rubber springs, rubber couplings and other rubber products with low dynamic stiffening and high damping.

Regarding the polymer waste used the following parameters for use:

epoxidized natural rubber: amount 45 to 70% by weight
Degree of epoxidation: in particular about 50%
- viscosity-stabilized natural rubber: amount 10 to 25% by weight.

Within the following experimental section Recipes (table 1) with test results (table 2) captured. Mixture variant A represents conventional rubber compound and compound variant B the recipe according to the invention, u.z. combined with a rubber coupling as an embodiment.  

table

Table 2

symbolism

Claims (4)

1. Rubber mixture for the production of rubber products with

• - low dynamic stiffening and
• - high damping

on the basis of natural rubber as well as usual mixture ingredients, such as fillers, plasticizers, anti-aging agents, cross-linking agents, zinc oxide and optionally other additives, characterized by the following natural rubber blends:

• - epoxidized natural rubber 45 to 70% by weight
• - viscosity-stabilized natural rubber 10 to 25 wt .-%.

2. Rubber mixture according to claim 1, characterized characterized in that in the epoxidized natural rubber about 50% of the double bonds are epoxidized. 3. Use of a rubber mixture according to claim 1 or 2 for the production of molded articles made of rubber or of composite articles made of rubber and metal and / or Plastic, especially rubber springs and Rubber couplings.