SU710608A1 - Carbon black-in-water dispersion composition - Google Patents

Description

one

The invention relates to compositions of aqueous dispersions of carbon black and can be used in the industry of carbon black and synthetic rubber.

The known composition of an aqueous dispersion of carbon black for blackened rubbers, including, by weight,%: carbon black 4-8, polymer (in the form of a latex or dispersion) 0, 25-0-0,015 and water 1. The known composition is not sufficiently stable and stratified during long-term storage.

The known composition of the water dispersion of carbon black, including carbon black, water-soluble polymers of acrylic acids, wt.%: 0.05-10 and water - at least 70 2.

This composition allows obtaining stable water dispersions of soot, while reducing the rate and degree of sulfur vulcanization of blackened rubber, since carboxyl groups contained in the acrylic acid copolymer slow down the process of vulcanization of rubbers. This dramatically reduces the performance of vulcanization equipment in the preparation of rubber products and leads to

to increase the consumption of expensive vulcanization accelerators, which increases accordingly the cost of products. In addition, rubber made of black rubber, obtained using the specified composition, have unsatisfactory wear resistance.

The purpose of the invention is to reduce

0 time vulcanization of polymer compositions (black rubber),

The goal is achieved by the fact that the proposed composition of the aqueous dispersion of carbon black includes, in weight,%;

five

Soot. 4-6

Polyethylene: 0.05-0.5 Water Else,

The difference of the proposed composition lies in the fact that it contains

0 as a water-soluble polymer polyethyleneimine and in the above ratio of components.

Polyethyleneilgane is a product of polymerization with ethylene compounds 5 and molecular weight of 30-100 thousand hours, i.e. polymerization number 6702220,

The polyethyleneimine macromolecules contain primary, secondary and

0

Tertiary amino groups, which are known to be actively active in the processes of sulfur vulcanite, accelerate it. Due to the indicated reactions: macromolecules of polyethylenimine are included in the structure of a vulcanising network of black filled rubber obtained using the specified composition. In addition, the primary and secondary amino groups, which have basic properties, interact in the preparation of the dispersion with carboxyl and phenolic groups on the surface of carbon black. This leads to a significant increase in the chemical interaction of the polymer-filler during the vulcanization of rubber and, accordingly, the wear resistance of rubber. At the same time, polyethylenimine, due to the harshness of the relatively polar amino groups in the side chains, has extremely good dispersing properties. Aqueous dispersions of carbon black, prepared with the use of a composition containing polyethyleneimine, have a very good stability during storage. The best results were obtained when the content of polyethylenimine in the proposed composition ranged from 0.01-0.5%. With a lower concentration of polyethyleneimine in the composition, a high stability of the carbon black dispersion is not achieved, and concentrations of more than 0.5% are also undesirable, as prepared with such a composition blackfilled rubber in the presence of sulfur will have an increased tendency to scorch, which makes it difficult to process into products. Rubber mixtures based on filled rubbers, obtained using the specified composition, are characterized by a higher rate and degree of vulcanization, and vulcanizates have better wear resistance than rubber based rubber filled rubber, obtained using known compounds.

Example 1. A 3 liter beaker is charged with 2 l of distilled water and 1 g of polystylenimine with a degree of polymerization of 1330. After stirring, a composition is obtained to obtain an aqueous dispersion of carbon black containing 0.05% polyethylene imine. A solution of 100 g is placed in a ball mill PM-100 highly active furnace soot with a specific geometric surface of 96 m / g and an oil number of 104 ml / 100 g, and 2 l of prepared composition is obtained. The contents are stirred for 12 hours and receive a 5% aqueous dispersion of carbon black. A soot control dispersion was also prepared on the composition consisting of water, carbon black and 0.05% copolymer of acrylic acid and sodium methacrylate with a degree of 5 polymerization of 3500 (a comet product). 20 MP each of the dispersions are cast into test tubes, left for storage and their condition is monitored. In dispersions with insufficient stability; the soot begins to coagulate and settle, with the result that after some time a transparent layer of the aqueous phase forms in the upper part of the dispersion. The thickness of this layer is measured.

Results of stability assessment. aqueous dispersions of saiki PM-100, obtained using the proposed and known composition are given in table 1,

T a

l and c

About About About 1 1 1 1

About 1 2

3

4 4 4.

.

About 1 3 4 5 5 5

not stratified

With constant stirring, 1600 ml of butadiene-cc methylstyrene rubber CKMS-30 ARK is added to 1600 ml of carbon black dispersion with a dry residue of 20% by weight, and then a mixture of 24% sodium chloride solution with a 2% solution of sulfuric acid taken in 4: 1 ratio to complete coagulation of the contents. The resulting black rubber crumbs are filtered, washed, and dried. 40 parts by weight of dried rubber are contained. soot per 100 weight hours Polymea Mooney test, a) viscosity is minimal. b) the start time of scorching, min. Defoe stiffness, rf Defoe recoverability, mm Optimum vulcanization time, min. Stress, at 300% elongation, kgf / cm Tear resistance, kgf / cm Elongation,% Residual length,% Abrasion , on MIR-1, .hour.

Example 2 A composition for the preparation of an aqueous dispersion of carbon black is prepared as in Example 1, but 0.1% polyethylene is taken from the weight of water. The results of testing the dispersion of carbon black and rubber mixtures based on black fuel prepared using this composition are given in gabl. 1 and 2.

Example .3. The composition for the preparation of an aqueous dispersion is prepared as in Example 1, but taken in 0.25% polyethyleneimine based on the weight of water. The results of testing the dispersion of carbon black and rubber mixture based on black rubber prepared with the radiation properties of filled rubbers based on them are preparing a rubber mixture of the following composition, weight, h, 6 utadi-c {.- methyl styrene rubber with polyethylenimine - 140, stearic acid - 2 , zinc oxide 5, altax 2, sulfur - 2. In parallel, a mixture of the same composition based on filled rubber with the same amount of comet product is prepared.

The properties of rubber compounds and vulcanizers are given in table. 2

table 2

a change in the composition indicated, are given in Table 1 and 2c.

Example 4 A composition for the preparation of an aqueous dispersion is prepared according to Example 1f but taken in 0.5% polyethyleneimine based on the weight of water.

The results of testing a dispersion of carbon black and a 1-bezine mixture based on black rubber prepared using: the indicated composition is given in Table. 1 and 2,

As can be seen from the above examples, the mixtures obtained using the composition with 0.5% polyethyleneimine have 4 times less time to start scorching, twice as large then 65 501400 1.8-5 1.84 1.86 100 82 6Q60 60171 80283 50450 1210 83181

the scorch rate, and the vulcanizates are characterized by more than twice the degree of structuring, assessed by stress at 300% elongation, and by 12% higher wear resistance compared to the known rubber compounds and vulcanite, which are obtained with the composition containing methacrylic copolymer acid and methacrylate (comet product). With a content of 0.05% polyethylenimine in the composition for preparing an aqueous dispersion of carbon black, the mixture is also significantly superior (about 1.5 times) to the control mixture with the comet product in terms of speed and degree of structuring, but the advantage of vulcanizers in wear resistance is not significant. Aqueous dispersions of carbon black, obtained on the basis of the proposed composition, are similar in stability to the well-known :: I will leave with the comet product.

Claims (2)

1. USSR author's certificate No. 447046, cl. C 08 C 1/14, 16.06.72 2. The UK patent 1431847, cl. At 01F 17/00, 04/14/76 (prototype).