“SUPRALOX”’ OVER-COATED RUBBER

A BRIEF DESCRIPTION

In rubber industry, e.g. for the production of motor vehicle tyres fillers are added to the rubber. Usually 40-50 kg of filler are added to 100 kg of rubber, and further additives, such as 5 kg of zinc oxide, 2 kg of stearine, accelerators, plasticizers and sulphur for vulcanization are also introduced.

For about 70 to 90 years, these products were used in the form of powders. Today, with the exception of a few countries with underdeveloped industries, they are used in the form of over-coated materials in Western Europe, the USA and other countries with developed industries.

Over-coated systems marketed under the brand name ‘SUPRALOX’ as a replacement of the old powdered products guarantee better-quality finished rubber products than competing over-coated systems of a similar nature. The process of their incorporation into natural rubber is more friendly to the environment and it saves more energy.

Evaluations hitherto performed at a TAURUS-EMERGÉ plant indicate that the homogenization of ‘SUPRALOX’ products in rubber takes place 25-30 % faster than that of other over-coated products, which translates into substantial savings in the cost of electricity.

95 % of the basic components that go into the ‘SUPRALOX’ products are of domestic origin, making the brand cheaper than similar products imported from abroad.

Zinc activators are employed in a process to create a complex compound to be used in the rubber industry. These modern over-coated products incorporate both zinc oxide and stearic acid applied as a wetting agent as well as other organic activators employed to prevent any reversal of cure.

In addition to the beneficial properties of modern activators, and indeed completing the advantages offered by them, the new products described in this brief introduction offer to prevent the reversal of cure as well. In fact, the salient benefit of the new product family is their remarkable performance in the prevention of the reversal of cure. To prevent the reversal of cure, any rubber formulation will include some zinc oxide (3-5 parts by weight) and stearic acid (2-3 parts by weight).

In the rubber industry, in addition to over-coated zinc oxide small amounts of activators are also used in order to further accelerate the process of incorporation. In the activators zinc is reacted, over stearic acid, with other fatty acids, too, i.e. a zinc soap is produced.

Using activators, the amounts of over-coated zinc oxide and stearic acid to be incorporated may be reduced to a small extent, but they cannot be made altogether unnecessary.

It is a further disadvantage that they are rather expensive!!!

In contrast to what has been described above, the solution offered by the SUPRALOX method may make expensive imported activators as well as the zinc oxide and stearic acid called for in the formula unnecessary by supplying all this in a single compound.

The preliminary evaluations and tests conducted at the Taurus laboratories in Szeged suggest that this product is capable of satisfying the various requirements related to the different quality grades aimed at in the rubber manufacturing process in terms of both natural and synthetic rubbers. Using the new product, multiple weightings (weighing in zinc oxide, stearic acid and activator) are set aside which in turn leads to savings in time.

Reductions in the length of time required for the process of incorporation to take place translates into proportionate savings in energy. The results of evaluations hitherto carried out on a small number of samples support the assumption that the quality of the rubber compounds improves, too.

In the past few years, with the introduction of increasingly stringent quality and environmental requirements, the use of activators has come into the prominence.

Zinc activators:

Zinkakt-1 for natural rubber and Zinkakt-2 for SBR and other synthetic rubbers

ZnO2 67 % 67 %
Stearine 9 % 9 %
Ultrasil VN-3 3 % 3 %
Aluoxihydrate 15 % 15 %
Dispersant Zn-1 6 % ---
Dispersant Zn-2 --- 6 %

SUPRALOX PRODUCTS ARE MODERN OVER-COATED FILLERS AND ADDITIVES FOR USE IN RUBBER AND PLASTIC PROCESSING INDUSTRY

General characteristics:

As a result of over-coating, the materials (both fillers and additives) do not give off dust, which yields the following advantages:

  • Being dust-free, these products are more friendly to the environment (some years before the use of powdered products in rubber manufacturing plants has been prohibited under the ISO standards adopted in Western Europe) and protect the health of workers(by eliminating the risk of silicosis.

  • Weighing becomes more accurate, thus, coupled with that high-capacity dust extractors are no more required, significant savings in costs can be attained.

  • No losses occur at weighing, which contributes to the improvement of product quality.

  • Storage life increases from 2-3 months to 2-3 years, because the basic components do not clump together and do not absorb moisture from the air during storage, and no floating dust escapes to the air from torn bags.

The incorporation of our over-coated products leads to an improvement of dispersity, which in turn improves product quality. Furthermore, the time required for incorporation is shortened by 25-30 %, which allows for proportionate savings in the amount of energy used. The constituents used in our products are those mainly employed in rubber industry formulas, consequently our prices are 30 % lower than those of competing products.

As an additional advantage, our products include almost the whole range used in the rubber industry, which allows for ample opportunity to design individual formulations.

We now briefly present our products used and tested industrially, products that have been proved to yield good results:

SUPRALOX fillers:

Designation:

R-1

R-2

(for rubber)

R-3

(for PVC)

M-1

(for polyester)

PE-1

Chemical composition:

Alu-oxihydrate content %

84.5

89.5

94.5

94.5

94.5

Silicon oxide content %

10.5

5.5

0.5

0.5

0.5

Stearine content %

2.0

2.0

2.0

----

2.0

Organophilic dispersant

3.0

3.0

3.0

5.0

3.0

Odour: that of a slightly aromatic chemical

Over-coated sulphur and metal oxide additives

Varieties

S-90

S-80

S-75

ZnO-80

MgO-80

TiO-80

TiO-60

Sulphur content %

90

80

75

----

----

----

----

Zinc oxide content %

---

---

---

80

---

---

---

Magnesium oxide content %

---

---

---

---

80

---

---

Titanium dioxide content %

---

---

---

---

---

80

60

Aluoxi-hydrate content %

5

12

17

12

12

14

33

Organic additive %

5

8

8

8

8

6

7

THE RECOMMENDED PRODUCTS BELONG TO ONE OF THE FOLLOWING 3 MAIN GROUPS

1. White fillers: For rubber products

General characteristics: this product is a free-flowing non-dusting material, which can be weighed in with high accuracy.

Being dust-free, it is environment-friendly and does not constitute a health hazard to workers. Whether processed in a closed or open mixer, the time of incorporation is shortened by 25-30 % as compared to other fillers, and produces improved levels of dispersity. Thus it is much better than the other recommended fillers, such as carbon black or silicate.

R-3: This filler comprises 95 % of aluoxi hydrate together with 3 % of an oily dispersant and 2 % of stearine.

Recommended uses: outer soles and heels of shoes and boots, industrial belts, moulded goods, component parts.

Its beneficial physical properties include the following:

  • Increased resistance to abrasion; fire-retardancy (its chemically-bound water content is 15-18 %, which upon subjected to flames becomes steam and retards or extinguishes the flames)

  • Reduces permanent distortion, and together with reinforcing black it increases tensile strength.

  • Its high electric resistance allows for its use in rubber or plastic cable fillers (it has been used, together with R-2, by Magyar Kábelművek, a Hungarian cable manufacturing company).

R-2: Its aluoxi-hydrate content is 90 %, and, as compared to R-3, it also includes 5 % silicate (Ultrasil V-3) for purposes of reinforcement.

Recommended uses: cable manufacture, motor vehicle tyre manufacture, extruded and injection-moulded products. Its physical properties are mostly identical with those of R-3. There are some differences, however:

  • Its density and specific strength is higher.

  • On the other hand, its fire retarding capacity is lower.

  • Its specific electric resistance is excellent, rendering it a favourite choice in the manufacture of prime-quality cables (e.g. trailing cables).

R-1: Made up of 85 % aluoxi-hydrate and 10 % silicate, it is mainly used in the manufacture of products where specific gravity plays an important role.

In contrast to the usual value of 1.9-2.1 gr/cm3, the specific gravity of aluoxi-hydrate is 2.4-2.6 gr/cm3 thus the weight of aluoxi hydrate to be incorporated as filling agent for unit volume is higher than the weight of the filler replaced by it. In addition to that, it is of higher activity. In other respects, its properties are similar to those of the two fillers described above.