DE3344159T1 - White filler and method of making the same - Google Patents

Description

PCT / HU83 / 00022 P 1 877 PCT

White filler and method of making the same Technical area

This invention relates to a white filler and a method for making the same. in the in particular, it relates to a white filler based on aluminum oxide and a process for the manufacture of the same. The invention also relates to Rubber and plastic compounds with a content of the white filler mentioned and rubber containing it and plastic products.

State of the art

It is known that various fillers are used in the manufacture of products from natural or synthetic rubber or plastics. The so-called black fillers represent an important group of the fillers mentioned; Sewer soot is the best-known representative of the black fillers. The encryption _'f turn of black fillers is, however, in several cases difficulties.

In addition to black fillers, another type of filler - so-called white fillers - is widely used used. These fillers are generally based on oxides or silicates of aluminum, Potassium, sodium, barium and magnesium. In the German patent no. 1 071 943 are fillers based on

of kaolin, which have an aluminum oxide / silica tr-ratio of over 0.85 and 0.2 to 0.6 % by weight

33U159

Containing thiuram disulfide. According to the Hungarian patent specification No. 147 411, white fillers essentially containing aluminum oxide are produced by heating aluminum hydroxide precipitated from the sodium aluminate with the aid of a separately produced inoculum by heating to a temperature between 30O ⁰ C and 750 ⁰ C. The disadvantage of this method is - as can also be seen from the text of Hungarian patent specification no. 147 411 shows - that only fillers with a grain size below 0.2 μ meet the requirements of the rubber industry.

According to another known method, aluminum hydroxide gel prepared by reacting aluminum sulfate with sodium carbonate or by acidifying sodium aluminate is used. However, the use of the fillers mentioned is accompanied by a number of disadvantages. For example, the fillers mentioned are very expensive, their effectiveness is not sufficiently high, considerable acid or alkali losses occur during their production and they can contain impurities which can catalyze the aging of rubber and are therefore very damaging.

Presentation of the invention

The purpose of the present invention is to provide of new fillers which can be produced by simple processes and which eliminate the above disadvantages.

According to a feature of the present invention is a white alumina based filler with a content of in the CaIcining furnace of the aluminum

_, 3 -

Oxide manufacturing process of the Bayer type formed "recycle powder" which is either surface treated or is separated from the particles with a grain size above 5 ρ, optionally mixed with known additives, in particular zinc oxide or sulfur and / or a plasticizer, aging retarder and Accelerator, provided.

It is known that in the course of the Bayer-type alumina manufacturing process, aluminum hydroxide is converted to aluminum oxide in a calcining furnace. The powder leaving the furnace is separated in an electrostatic powder separator, in which 70 to 75% aluminum oxide is subjected to electrolysis and 25 to 30% powder which cannot be used for electrolysis is separated out. The latter - so-called "return powder" - is returned to an earlier stage of the manufacturing process, namely to the aluminum hydroxide precipitation phase. This has the disadvantage that the powdery substance has to be dried and calcined before being introduced into the cycle, and this causes considerable rejects and / or energy losses.

It was surprisingly found that by using the isolated in the electrostatic powder separator and to an earlier stage of the Manufacturing process mentioned

"Return powder s" fillers with very excellent ';'

Properties suitable for use in the rubber and plastics industry can be obtained be able. ■> ■

In accordance with another feature of the present invention is a method of making white Filler based on aluminum oxide, which s

a) the subjection of in the calcining furnace of the Bayer-type alumina manufacturing process "recycle powder" Surface treatment with a solid or liquid agent; or

b) separating the alumina production process in the calciner of the Bayer-type "recycle powder" formed from the particles having a grain size greater than 5 μm;

and optionally mixing the product obtained by procedure a) or b) with known additives, in particular with zinc oxide, sulfur, an aging retarder and / or an accelerator and / or a plasticizer is provided.

According to a preferred embodiment of the method surface treated "return powder" is used. According to another preferred feature of the invention is a "recycle powder" as the starting material, which has a loss on ignition of 3 to 30% by weight, a molecular weight of 110 to 145, a specific gravity of 2.5 to 3.0 g / cm, an aluminum content of 36 to 50% by weight and a hardness from 4.5 to 6.5 according to the Mosh scale, ο It is particularly advantageous to use a "return powder", which has a loss on ignition of 6 to 16% by weight, that is, to use o <-, ß-, Y-aluminum oxide hydrate.

The surface treatment can be done with any suitable

solid or liquid agents used in rubber or plastic preparations. Such are the following solid or liquid compositions for use in the method of the present invention particularly suitable: stearic acid, an oil - preferably extraction oil or watchmaker's oil -, an organic silanol or silane, diethylene glycol, calcium stearate, dioctyl phthalate, N-phenyl-N'-isopropyl-p-p-pheriylenediamine, Diamino-cyclohexyl-phenylene, phenyl-ß-naphthylamide, aldol - ^ - naphthylamine, a alkylated phenol, 2-mercaptobenzimidazole, or dichlorodifluoromethane, or a mixture thereof.

According to a particularly preferred embodiment of the present invention is a mixture of naphthic acid and triethanolamine - with a content of about 10 to 30% by weight of naphthenic acid - in an amount of 0.1 to 10.0% by weight, based on the weight the "return powder" is used.

The surface treatment is carried out at the room temperature or carried out with heating. The surface,

Acting according to the present invention can use any for applying solid or liquid agents suitable for powdery substances Device or procedure are carried out. The treatment can preferably be carried out with homogenization be performed. Another method is to use a nozzle or ( an atomizer is applied to the surface of the "return powder". "■

According to procedure b) the "return powder" is of the particles with a grain size above

5 ρ exempted. This can preferably be done by known Procedures, for example by grinding or sieving, are carried out.

The filler according to the present invention can be used alone (per se) or together with known ones other fillers can be used.

According to another feature of the present invention, rubber and plastic articles are with a content of the fillers disclosed above. The fillers according to the present invention Can be used in a wide range of rubber and Plastic objects are used. The following rubber and plastic items are for illustrative purposes only half of the list: tires, technical rubber articles, seals, sole articles, panels, Floors, cut strips, shaped or compression molded pieces, panels, extruded or pressed pipes, Cable covers, etc.

It has been found that the fillers according to the present invention have the properties of Rubber and plastics in a considerably larger size Improve dimensions than the known fillers. For best results, use surface treated "Recycle powder" is obtained from fillers produced, but also from the particles with a grain size of more than 5 ju freed "return powder" manufactured fillers give good results. When adding the fillers of the present invention in relation to rubber objects, the tensile strength and hardness are increased to a significant extent, and so is the abrasion is reduced considerably; these benefits are at

particularly important in the manufacture of soles and tires. Except in rubber based of natural rubber are the fillers of the present invention Invention also for use in a mixture of artificial rubbers (e.g. nitrile rubber) mixtures made of butadiene and styrene, etc.) are useful. Another benefit of the filler of the present invention is that in some cases it can produce the necessary amount of costly Accelerators decreased; namely, it was found that the filler of the present invention Accelerator adsorbs to a lesser extent than the sewer soot or the known white fillers.

When incorporating the fillers of the present Invention in polyvinyl chloride compositions, the tensile strength is reduced to a lesser extent than in Use of known fillers, while on the other hand - to a very high degree, even by several Orders of magnitude of abrasion are reduced and the specific electrical resistance is increased.

The fillers of the present invention are also suitable for use in the construction industry. When incorporating the fillers of the present invention in plastics is - in contrast to those used in large quantities known inert fillers, such as kaolin, calcium carbonate, quartz sand - excellent flame retardant observed WIR {effect. The bound water content of the filler of the present invention gives off ^{steam at a temperature of about 250 °} C., which suppresses the flames. Another benefit of the

33U159

The filler of the present invention relies on the fact that it has dielectric strength and improves the leakage current resistance.

According to a preferred embodiment of the present Invention are fillers with a content of 70 to 99 wt .-% sulfur and 30 to 1 wt .-% surface-treated "return powder" provided. The products mentioned can either by mixing 70 to 99 wt .-% sulfur with 30 to 1% by weight of surface treated "recycle powder" or by mixing sulfur with "recycle powder" and subjecting the homogenized mixture to a surface treatment disclosed above.

Industrial applicability

The white fillers of the present invention are suitable for use in rubber and plastic industry and also in the construction industry.

Ways to carry out the invention

Further details of the present invention can be found in the following examples, without The scope of protection of the invention is limited to the examples mentioned, which are for illustration purposes only serve to restrict.

example 1

8.5 kg "return powder" (loss on ignition: 12.05%; specific weight: 2.6 g / cm; aluminum content: 42%; Hardness according to the Mosh scale: 5.0) are in one

159 AO.

Homogenizer mixed with 1 kg of precipitated silicate. The mixture obtained in this way is mixed with a mixture of 0.2 kg of stearic acid, 0.25 kg of extraction oil, 0.03 kg of triethanolamine, 0.01 kg of naphthenic acid and 0.01 kg of silanol with heating to 72 ° C surface treated.

Example 2

9.4 kg "return powder" (loss on ignition: 15.45%; grain size: 88% between 1 and 5 M; specific weight: 2.8 g / cm, aluminum content: 39%; hardness according to the Mosh scale: 4.9) are surface-treated in a homogenizer with a liquid mixture of 0.2 kg of stearic acid, 0.3 kg of extraction oil and 0.1 kg of silanol with heating to 72 ^° C.

Example 3

Proceed as described in Example 2, except that the silanol is replaced by 0.1 kg of diethylene glycol, triethanolamine or naphthenic acid.

Example 4

9.5 kg of "return powder" (loss on ignition: 8.6%; grain size: 1 to 2Ou; aluminum content: 43%; hardness according to the Mosh scale: 5.2) are surface treated in a homogenizer with a mixture of 0.2 kg of calcium stearate subjected to 0.3 kg of dioctyl phthalate and 0.02 kg of triethanolamine at 20 ⁰ C.

'- 10 -

- to -

Example 5

For comparison purposes, gum compositions are made from the fillers of the present invention and known fillers (sewer black and precipitated silica). The characteristic Features and properties are determined by standard procedures after vulcanization.

The results obtained are summarized in the following tables. In Table I is the Composition of the rubber compound (in parts by weight) disclosed. Columns I to IV of Table I refer to on the composition of manufactured using the fillers according to the invention Mixtures, while columns V to VI show the composition of mixtures containing show known comparative fillers. The test results are compiled in Table II.

- 11 -

Xl.

Table I.

composition

II

III

IV

VI

Natural rubber 10, 0 10 r ° 10, 0 10, 0 10.0 10.0 Zinc oxide ⁰ I. 5 0 / 5 °) 5 °> 5 0.5 0.5 Stearic acid 0, 15th 0 , 20 15th 0, 20th 0.25 0.25 Filler after
the example 1 0 3 > ° _ _ _ mm Filler after
the example 2 - - 0 0 - - Sewer soot,
Type HAF - _ 0 5 * 0 Likes this
Silicon dioxide - 3 , ° - _ 5 _; 0 Extraction oil 0. 35 0 ') ** 32 41 0.5 0.5 Aging
delay ; ⁰ y 10 0 , 10 10 0, 10 0.10 0 _? 10 Santoflex IP
MBTS ° -> 20th
05 0
0 Ϊ ²⁰
, 05 20th
05 20th
10 0.20
0 _? 10 0.20
0 ^ 10 Vulcacid DPG - - - - 0.05 0.05 CBS 10 0 , 10 10 0, 05 - - sulfur ⁰ y 17th 0 , 17th °; 17th ⁰ y 15th 0.15 0 _; 15th

Kb.

Table II

Test attempt

I.

Gurami mixture No.
II. III. IV. V.

VI,

Tensile strength, ρ kg / cm

Elongation at break, % hardness
(Shore A ⁰ )

Permanent elongation, %

Tear Strength, kg / cm ^

Abrasion -, (Schopper mm)

Young module (MPa / m2)

200 220 500 500

52

56

240 100 170 550 350 400

60

57 56

30-32 30-32 34-36 44-46 30-32 32-34

200-200 200

8 _; 7 120

250

15.4 7.3

- .13 -

From the above data it appears that the tensile strength and hardness of the rubber containing the filler according to the invention are considerably better than the corresponding properties of rubber of the same composition but containing known fillers and at the same time the abrasion is significantly reduced. According to the comparison tests mentioned, the abrasion is reduced by almost 50% , which is particularly useful in the manufacture of sole objects and tires.

Example 6

Fillers produced from the "return powder" surface-treated according to Example 4 are shown in hard and soft polyvinyl chloride mixtures of various compositions incorporated and the properties of the products thus obtained are compared with those of polyvinyl chloride mixtures containing by conventional Process produced fillers compared.

In Table III the composition of the mixtures (in parts by weight) and in Table IV the measurement results are given. Tables III and IV refer to soft polyvinyl chloride.

- 14 -

. « Λ Λ Λ

/ 15 *.

33U159

Table III II. III. 100 100 composition • I. 50 50 Polyvinyl chloride
grains 100 2 2 Dioctyl phthalate
plasticizers 48.8 2 2 stabilizer 2 - - Naftovin T-3 2 40 Filler after
Example 4 40 C alc iumc carbonate
and kaolin

C alc ium carbonate and silicon dioxide

40

Table IV

Test attempt

Mixtures
I.

II.

IV.

Tensile strength, kg / cm 10096 module kg / cm ² abrasion (Schopper mm

Specific electrical resistance

0hm x cm

146 118 116 89 76 70 325 522 537

3.4x1O ¹⁶ 3.2x10 ¹³ 6.5x10 ¹²

- 15 -

It can be seen that 'the properties of the under Use of the fillers according to the present invention produced significantly better than plastics those of known fillers containing plastic mixtures. Except for a minor decrease the tensile strength and a significant reduction in abrasion, it is particularly noteworthy that the electrical resistivity is increased by 3 or even 4 orders of magnitude.

Example 7

85 parts by weight of sulfur and 10 parts by weight. "Return powder" are homogenized and surface-treated with 5 parts by weight of a liquid mixture consisting of oil, fatty acid ester, naphthenic acid and triethanolamine. . ''

Example 8 '

A homogenized mixture of 60 parts by weight of "reflux powder" and 35 parts by weight of kaolin is added 5 parts by weight of a liquid mixture consisting of made from oil, fatty acid esters, naphthenic acid and triethanolamine, surface treated.

16 -

Claims (19)

"I ~ 334-159 / η. Claims 1. A hot filler based on aluminum oxide containing in the calciner of the alumina manufacturing process "return powder" formed by the Bayer type, which is either surface-treated or is separated from the particles with a grain size greater than 5 u, optionally in a mixture with known additives, in particular zinc oxide or sulfur and / or a calibrator, aging retarder and / or Accelerator. 2. Filler according to claim 1 with a content of a "return powder", which has a loss on ignition of 3 to 30% by weight, a molecular weight of 110 to 14-5 »sin specific Weight from 2.5 to 3> 0 kg / cm, an aluminum content of 36 to 50% by weight and a hardness of 4, 5 to 6.5 according to the mosh gkala. hat. 3. Filler according to any one of claims 1 to 2 with a surface treated "recycle powder". 4-, filler according to claim 3 with a content of a with stearic acid, an oil, preferably extraction oil or watchmaker oil, an organic silanol or silane, diethylene glycol, calcium stearate, dioctyl phthalate, N-phenyl-H'-isopropyl-p-phenylenediamine, diamino cyclohexyl-phenylene, phenyl-ß-naphthylamine, aldol-c * -naphthylamine, an alkylated phenol, 2-mercapto-benzimidazole or -ichlorodifluoromethane or a mixture of the same surface-treated "reflux powders". _; 5 · filler according to claim 4 with a content of one with 0.1 to 10.0 wt .- ^ a mixture of Kaphthen - 17 - - ³ Hi? - acid and triethanolamine surface treated "reflux powder ". 6. filler according to claims 4- to 5 with a gel. j stop at a with a mixture of stearic acid, an i oil, preferably extraction oil or watchmaker oil, an or-! Ganic silanol or silane, naphthenic acid and triethanol ^: amine surface-treated "return powder". ; ■ '■ ...- j 7. filler according to claims 5 to 6 with a content of "return powder" surface-treated with 0.1 to 20% by weight of a solid or liquid agent. ; ■ ■ ■ ■ '■■■' '..-'! 8. filler according to claim 1 with a content of 70 to 99% by weight sulfur and 50 to 1% by weight surface-treated j tem "return powder". ! 9 · Method of making white filler on
based on alumina a) Subjecting in Aluminum Calciner; Oxydherctellungsververfahren of the Bayer type formed "return powder" of the surface treatment with a solid or ! / liquid Ivattel; , j ■ ■ '. i or b) the separation of the aluminum oxide thermosetting process in the calcining furnace of the Bayer-type "recycle powder" formed from the particles having a grain size greater than 5μ; and optionally mixing the product obtained by procedure a) or b) with known additives, in particular with zinc oxide, sulfur, a
Aging retarder and / or an accelerator and / or
a plasticizer. - 18th 33U159 10. The method of claim 9, which includes the use of a "recycle powder" with a loss on ignition of 3 to ■ J> 0 wt.? '?, a molecular weight of 110 to 145, a specific gravity of 2.5 to 3.0 kg / cm, an aluminum content from 3S to 50 wt .-; S and a hardness of 4.5 to 6.5 according to the mosh-okala. 11. A method according to any one of claims 9 to 10 which comprises subjecting the "recycle powder" to a surface treatment 'includes. . 12. The method according to claim 11, which carries out the surface treatment with stearic acid, an oil, preferably extraction oil or watchmaker oil, an organic one Silanol or silane, diethylene glycol, calcium stearate, Dioctyl phthalate, N-phenyl-N'-isopropyl-p-phenylenediamine, Diamino-cyclohexyl-phem / len, phenyl-ß-naphthylamine, .. • .Idol-crt-naphthylamine, an alkylated phenol, 2-mercapto- -benzimidazole or dichlorodifluoromethane or a mixture the same includes. 13. The method according to claim 13, which includes carrying out the surface treatment with 0.1 to 10.0% by weight a mixture of waphthenic acid and triethanolamine. 14. A method according to any one of claims 11 to 13, which comprises carrying out the surface treatment with a mixture of an oil, preferably Extro.ktionsöl watchmaker or oil, an organic silanol or 3ilan, ^I:; aphthensäure 'and l'comprises riäthanolamin. 15 · The method according to any one of claims 11 to 14, which includes performing the surface treatment Use from 0.1 to 20% by weight of a solid or liquid Means, based on the weight of the "Rücklaufpul-. vors "- um ^ Tfc. - 19 - ■ 16. The method according to claim 9, characterized that you 70 to 99 Gev; .-% sulfur with 30 to 1 wt.; of surface treated "return powder" or blending from 70 to 99% by weight sulfur with recycle powder and subjecting the homogenized mixture to a Surface treatment according to claim 9 comprises. 17 · The method of claim 9 including removing of particles with a grain size greater than 5 P- should be selected or seven includes. 18. A rubber or plastic compound which contains white fillers with a content of "return powder" formed in the calcining furnace of the Bayer-type aluminum oxide production process, which is either surface-treated or separated from the particles with a grain size of more than 5 p- , and possibly known additives, , in particular zinc oxide or sulfur or an accelerator and / or an aging retarder and / or a leveling agent. 19. Rubber and plastic objects, in particular Claws, jets, sole objects, panels ,. Floors, Section bands, shaped or compression molded Pieces, plates, extruded or pressed pipes or cable covers containing a filler any one of claims 1 to 8. - 20 -