Polymer powder composition for coating
(57) Abstract:The invention relates to the field of powder compositions of high-density polyethylene designed for the formation of corrosion protection coatings on metals, with improved performance characteristics. A composition comprising a high-pressure polyethylene and bismaleimide, further comprises 4,4'-diamino-3,3'-dichlorodiphenylmethane in the following ratio, wt.%: the high-pressure polyethylene 97,0-99,0, bismaleimide 0,5-1,0, 4,4'-diamino-3,3'-dichlorodiphenylmethane 0.5 to 2.0. The objective of the invention is to provide a polymer composition having improved adhesion to metal, water resistance and resistance to cathodic detachment. Technical solution allows to increase the water resistance of coatings 1.9-2.1 times, while resistance to cathodic flaking increases from 1.8 to 3.3 times. table 1. The invention relates to the field of powder compositions of high-density polyethylene designed for the formation of corrosion protection coatings on metals, with improved performance characteristics.It is known that coatings on the basis of high-pressure polyethylene have a low level of adhesion and vodostoykomu polyethylene to metals.Closest to the technical essence is a polymer powder composition containing polyethylene and bismaleimide General formula
< / BR>where R is
< / BR>in the following ratio, wt.%:
The high-pressure polyethylene - 94,0-99,5
Bismaleimide - 0,5-6,0
(see Stoyanov O. C., Debordieu R. J., and others, the Influence of bismaleimides on the structure and properties of polyethylene coatings. Plastic masses, 7, 1999, S. 7-12).The disadvantages of the known compositions are low resistance, poor resistance to cathodic peeling of the formed coatings.The objective of the invention is to provide a polymer composition having improved adhesion to metal, water resistance and resistance to cathodic detachment.Technically, the task is solved in that the polymer powder composition containing polyethylene and bismaleimide General formula
< / BR>where R is
< / BR>further comprises 4,4'-diamino-3,3'-dichlorodiphenylmethane in the following ratio, wt.%:
The high-pressure polyethylene - 97,0-99,0
Bismaleimide - 0,5-1,0
4,4'-Diamino-3,3'-dichlorodiphenylmethane - 0,5-2,0
The high-pressure polyethylene powder, a particle diameter of less than 315 μm, unstabilized, melting point 108oWith, the melt flow index of 7.0 g/10 min (GOST 16337-77).N, N'-(Phenylene-1,3)bismaleimide - crystalline powder, molecular weight of 268%, melting point 204-205oC; is issued by the industry (THE-6-14-1004-87). Structural chemical formula
< / BR>4,4'-Dithiobis(N-phenylmaleimide) - crystal fine light yellow powder molecular weight of 408 units, melting point 157oC. is Issued by the industry (THE 6-14-980-73).Structural chemical formula
< / BR>4,4'-Diamino-3,3'-dichlorodiphenylmethane - fine light-grey powder, melting temperature pp. 103 -- 110o(THE 6-14-980-84), is issued by the industry. Structural chemical formula
< / BR>Obtaining all of the substances included in the proposed composition, easy to implement and is produced by.The invention is illustrated by the following examples of specific performance.Example 1.Powder high-pressure polyethylene with a particle size of not more than 315 mkalimutan and 4,4'-diamino-3,3'-dichlorodiphenylmethane ratio 98,0-1.0 to 1.0 wt.%. The resulting composition is applied on a polished plate made of steel St-20 size HH,3 mm, the sample is placed in a heat chamber and upravlyaut for 20 min at 220oC. Cooling produce in air at room temperature. Floor test for resistance to cathodic flaking in the environment of 0.1 normal sodium chloride solution at room temperature by the method MI 514-01-83 /test Methodology outer coating of steel pipes with a diameter of 820-1420 mm for oil and gas/. Evaluation of the resistance of the coating to the cathode peeling is the diameter of the defect (loose cover) for 8 h test at a voltage of 6 in. For testing water resistance of the coating is placed in a container of water at room temperature. Studies conducted on samples with cut edges square 6x6 cm2. The resistance is determined by the time of the beginning of the delamination of polymeric coatings from metal.Examples 2, 3, 4.Similar to the previous example in composition, changes the content of 4,4'-diamino-3,3'-dichlorodiphenylmethane from 0.5 to 2.0 wt.%.Example 5( the prototype).A polymer composition was prepared in a mode similar to the previous examples, the following ratio of components, mA="ptx2">A polymer composition was prepared in a mode similar to the previous examples, in the following ratio, wt. %:
The high-pressure polyethylene 99,5
4,4'- Dithiobis(N-phenylmaleimide) 0,5
Examples 7, 8, 9, 10.Similar to example 1 in the receive mode, instead of N, N'-(phenylene-1,3)of bismaleimide taken 4,4'-dithiobis(N-phenylmaleimide).The content of 4,4'-diamino-3,3'-dichlorodiphenylmethane varies from 0.5 to 1.8 wt.%.Data on the composition of compositions and properties shown in the table.From the table it is seen that the proposed polymer composition on the basis of high-pressure polyethylene, containing both bismaleimide and 4,4'-diamino-3,3'-dichlorodiphenylmethane, than the known compositions based on water-resistance and resistance to cathodic detachment.Thus, as can be seen from the examples of embodiment, the coating obtained on the basis of the inventive polymer powder compositions, compared to the coatings obtained on the basis of the prototype, have 1.9-2.1 times greater resistance and 1.8-3.3 times greater resistance to cathodic detachment. The resistance to water and cathode peeling characterize the polymeric coating adhesion to metal is tocorrosion destination. Polymer powder composition for coatings, including high-pressure polyethylene and bismaleimide General formula
< / BR>where R is
< / BR>< / BR>characterized in that in addition it contains 4,4'-diamino-3,3'-dichlorodiphenylmethane in the following ratio, wt. %:
The high-pressure polyethylene - 97,0 - 99,0
The specified bismaleimide - 0,5 - 1,0
4,4'-Diamino-3,3'-dichlorodiphenylmethane - 0,5 - 2,0
FIELD: cathodic protection of metalwork.
SUBSTANCE: proposed paint-and-varnish material for corrosion protection of metalwork includes electrically conducting film-forming agent (electrically conducting polyethylene) and carbon nanotubes, from 10 to 80% of volume of paint-and-varnish material which increase electric conductivity and resistance to aggressive media and consequently mechanical strength of metalwork. Proposed paint-and-varnish material may additionally contain high-dispersed zinc powder ensuring additional cathodic protection from 40 to 90% of volume of paint-and-varnish material.
EFFECT: enhanced efficiency of corrosion protection of metalwork during protracted period of operation due to smooth electrical potential equal to potential of metalwork being protected.
5 cl, 1 tbl
FIELD: chemistry; insulation.
SUBSTANCE: invention pertains to a cable with a coating layer, made from waste materials. The cable consists of at least, one conductor with at least one transfer element and at least one layer of coating. The coating material contains between 30 mass % and 90 mass % of the overal mass of the coating material, at least, first polyethylene with density not more than 0.940 g/cm3 and melt flow index from 0.05 g/10 min. to 2 g/10 min., measured at 190°C and a load of 2.16 kg in accordance with standard ASTM D1238-00, and quantity from 10 mass % to 70 mass % of the overall mass of the coating material, at least, second polyethylene with density of more than 0.940 g/cm3. The first polyethylene is obtained from waste material. Use of at least, one polyethylene with density of more than 0.940 g/cm3 in the recycled polyethylene allows for obtaining a layer of coating, capable of providing for mechanical characteristics, in particular, breaking stress and tensile strength, comparable to characteristics of primordial polyethylene. The stated coating layer is preferably used as an external protective coating.
EFFECT: obtaining of a new type of cable insulation.
43 cl, 9 dwg, 4 tbl, 10 ex
SUBSTANCE: plastic composition with low viscosity, containing polyethylene with molecular mass of 1300-2700 - 100 pts.wt, and polyethylene with molecular mass of 1080-1250, or diesel fuel or engine oil instead of the latter - 10-20 pts. wt.
EFFECT: coating is water resistant, elastic, frost resistant, weather resistant and corrosion resistant.
SUBSTANCE: composition with multimodal distribution of molecular weight has density between 0.94 and 0.95 g/cm3 at 23°C and melt flow index (MFI190/5) between 1.2-2.1 dg/min in accordance with ISO 1133. The composition contains 45-55 wt % low molecular weight homopolymer A of ethylene, 30-40 wt % high molecular weight copolymer B of ethylene and another olefin containing 4-8 carbon atoms, and 10-20 wt % ultrahigh molecular weight copolymer C of ethylene and another olefin containing 4-8 carbon atoms. The composition has high processibillity and resistance to mechanical loads and breaking, especially at temperatures below 0°C.
EFFECT: flawless coating for steel pips has mechanical strength properties combined with high hardness.
10 cl, 1 tbl, 1 ex