RU2562272C1 - Monolayer composite thermoplastic coating - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: monolayer composite thermoplastic coating contains at least one homo- or copolymer of ethylene and/or ethylene-propylene rubber (component A) with density of 0.940-0.980 g/cm³; at least one homo- or copolymer of propylene (component B), such as a block-copolymer of polypropylene, polypropylene, a mixture of polypropylene and ethylene-propylene monodiene (EPDM) or ethylene-propylene rubber with density of 0.860-0.920 g/cm³; a homo- or copolymer of graft ethylene, which is grafted with a functional monomer, such as carboxylic acid or a derivative thereof, such that there is 98 wt % ethylene per 2 wt % carboxylic acid or derivative thereof, a dye - 40-50% carbon black concentrate, a stabiliser complex, such as pentaerythrol tetrakis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; 2,6-di-tert-butyl-para-cresol; tris(2,4-di-tert-butylphenyl)phosphite; disteril thiodipropionate. Component C is grafted with a functional monomer, such as carboxylic acid or a derivative thereof, such as maleic acid.

EFFECT: use of the monolayer coating instead of a three-layer system enables to coat pipes with only one material without using an adhesive owing to that Metalen PE-21 is a universal material having high technological effectiveness, characterised by adhesive properties and a top protective coating at the same time; replacing the three-layer pipe coating system with a monolayer system reduces material consumption and improves application efficiency.

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Description

The invention relates to chemistry and polymer composite materials.

From the prior art, a three-layer coating is known that is used to protect the outer surface of steel pipes intended for construction and gas pipelines, oil pipelines, oil pipelines of underground and underwater laying, for the construction of protective casings for transitions of oil pipelines and oil pipelines through natural and artificial barriers.

The system consists of:

- a layer of powder epoxy primer (thickness 60-200 microns). Examples of epoxy primers used can be Eurokote 712PP, Karumel EX4413-L300, Scotchkote (http://www.ecpl.ru/articles/coat.pdf),

- an adhesive layer that reacts with an epoxy primer (thickness 200-400 microns). Examples of adhesives used include Metalen APE-1, Borcoat ME0420, YUHWA HIDEN A015E, Orevac 18342N (http://www.optomvse.ru/building/m/242481_138_truby_pnd_.html, as well as http://innoprod.startbase.ru products / 23646 /),

- the outer polyethylene layer with a thickness of 1.5-3.0 mm. Examples of materials used can be Metalen PE-1, YUHWA HIDEN P601 (http://www.optomvse.ru/building/m/242481_138_truby_pnd_.html, as well as http://innoprod.startbase.ru/products/23646/).

Closest to the claimed is a protective coating based on a polymer component described in patent RF 2392291, designed to protect metal surfaces for aggressive environments.

Unlike the known ones, the claimed invention, conventionally named Methlen PE-21, replaces the adhesive layer and the upper polymer layer. Thus, the structure will have two layers on the steel pipe instead of three: a layer of powder epoxy primer and a layer of polyethylene layer Methene PE-21, which has adhesive properties. A monolayer coating of Metalen PE-21 is the use of one layer on top of an epoxy primer instead of two.

The technical result of the claimed monolayer coating - the use of a monolayer coating instead of a three-layer system will allow pipes to be coated with only one material without the use of adhesive due to the fact that Metalen PE-21 is a universal material that has high processability, characterized by the properties of adhesive and top protective coating at the same time. At the same time, replacing a three-layer pipe coating system with a monolayer system will reduce material costs (with a three-layer system, a total protective layer thickness of 3-6 mm is required, and with a monolayer coating of 2-4 mm, this saves 30% of the starting material) and increase productivity during application ( due to minimal shrinkage of the material, it is possible to increase the linear speed of applying the material to the pipe up to 20 m / min).

The technical result is achieved in that a monolayer composite thermoplastic coating containing at least one ethylene homo- or copolymer (component A) with a density of 0.940-0.980 g / cm ³ with a content of 50-90 wt.% In the final product. hours;

at least one propylene homo- or copolymer (component B), such as a block copolymer of polypropylene, polypropylene, a mixture of polypropylene and ethylene-propylene monodiene (EPDM) or ethylene-propylene rubber with a density of 0.860-0.920 g / cm ³ containing it in the final product 10-30 parts by weight;

a homo- or copolymer of grafted ethylene onto which maleic anhydride is grafted (component C), so that 98 wt. % ethylene accounts for 2 wt.%. maleic anhydride, to provide in the final composition of maleic anhydride of 0.1-0.5 wt. h

dye - 40-50% carbon black concentrate in an amount of 5-8 wt. hours

a complex of stabilizers such as pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate; 2,6-di-tert-butyl-para-cresol; tris (2,4-di-tert-butylphenyl) phosphite; disteryl thiodipropionate with their content in the final product of 0.1-0.8 parts by weight

Component C is grafted with a functional monomer such as carboxylic acid or a derivative thereof such as maleic acid.

Preferably, component A is high density polyethylene (HDPE) or a mixture of high density polyethylene, component B contains at least 10 parts by weight of propylene. and is a mixture of several polymers or contains EPDM, and component C is grafted with maleic anhydride.

Preferably, component A is an alpha-olefin with 2-30 carbon atoms.

It is possible that component A is a comonomer with 1-butene, 1-pentene or 1-hexene.

The implementation of the invention.

The proposed product is called Methlen PE-21, contains at least one homo- or ethylene copolymer (A) having a density of 0.940-0.980 g / cm ³ and at least one propylene homo- or copolymer (B), having a density of 0.860-0.920 g / cm ³ ; however, this mixture also contains a homo- or copolymer of grafted ethylene (C). According to the invention, component C and A are the same polymers. Preferably, component A is high density polyethylene (HDPE) or a mixture of high density polyethylene. Polymer A may be a mixture of several polymers. The melt flow rate (190 / 2.16) for one of the polyethylene A is less than 10.0 g / 10 min, preferably 3.0-6.0 g / 10 min. Moreover, the content of component A in the final product should be 50-90%.

Component B may be: a polypropylene block copolymer; polypropylene; a mixture of polypropylene and ethylene propylene monodien (EPDM) or ethylene propylene rubber. Preferably, polymer B, which may be a mixture of several polymers or contain EPDM, should contain at least 10% propylene. Moreover, the content of component A in the final product should be 10-30%.

Component C is grafted with a functional monomer. An example of grafted monomers can be carboxylic acids and their derivatives, for example maleic and itaconic. Maleic anhydride is most preferred. The grafting is carried out by heating the grafted polymers at elevated temperatures (150-280 ° C) in the presence of a radical initiator, e.g. The amount of grafted monomer is selected appropriately to obtain 0.1-0.5% maleic anhydride in the final composition. The amount of grafted maleic anhydride is determined using infrared spectroscopy.

In addition, Metalen PE-21 must contain a dye and a complex of stabilizers. Examples of dyes are 40-50% carbon black concentrates. Accordingly, the dye content should be 5-8%. Examples of system stabilizers are pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate; 2,6-di-tert-butyl-para-cresol; tris (2,4-di-tert-butylphenyl) phosphite; disteryl thiodipropionate. Their content in the final product should be 0.1-0.8%.

The melt temperature in the production of Methylene PE-21 should be 100-250 ° C.

EXAMPLE 1

Composition: a monolayer composite thermoplastic coating contains a homopolymer of ethylene (Snolen EP 0.26 / 5 IN, Tipelin 7100M) with a density of 0.940 g / cm ³ containing 70 wt.% In the final product. hours; block copolymer of polypropylene (PP44458, Hostalen PP, PP8300G) with a density of 0.860 g / cm ³ containing 10 wt.% in the final product. hours; ethylene homopolymer (EP Snol 0,26 / 51N, Tipelin 7100m, Snol 13 / 56S, Sabic 318V) to which maleic anhydride is grafted (manufactured TAIYUAN Industrial. Inculcation grafting is carried out by heating the polymers at elevated temperatures (150-2800 ° ^C) in in the presence of a radical initiator, tert-butyl hydroperoxide (in other examples, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-tert-butyl peroxide, tert-butyl cumene peroxide, methyl ethyl ketone peroxide.) in the final composition of maleic anhydride 0.2 wt.h, dye - 40% carbon concentrate soot at stake Only 8 parts by weight, a complex of stabilizers pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate and 2,6-di-tert-butyl-para-cresol with a content in the final product of 0.1 wt. h. The pipes are heated to a temperature of 220 ° C. Apply any of the known epoxy primers, for example, well-known brands such as Eurokote 712PP, Flywheels Nero-9005 and the like, and a layer claimed in accordance with the present invention is coated on the epoxy coated steel pipe. Metal-PE-21 coatings. The melt temperature at the exit of the extruder is 250 ° C. Get a two-layer coating to protect metal surfaces, consisting of a layer of powder epoxy primer of the claimed composite thermoplastic coating. As a result, the following additional positive factors are obtained:

1) reducing the load on the engine from 550-580 A to 470-490 A, the consequence of this is an increase in the service life of the equipment; the possibility of increasing productivity at the released capacities - the extruder designed for applying adhesive is freed; reduction in the cost of finished products; reduction in energy costs; increase in equipment overhaul cycles; 2) simplification of the technological chain of material production; 3) reducing the risk of technological errors when loading raw materials; 15-20% reduction in the risk of obtaining substandard material; 4) a reduction in the cost of transport services by 20-30%; 5) reducing the load on the warehouse and, accordingly, reducing the cost of warehouse logistics and, as a result, the release of warehouse space).

EXAMPLE 2

Composition: a monolayer composite thermoplastic coating contains component A, is high density polyethylene (HDPE) 0.960 g / cm ³ with a content of 60 parts by weight in the final product; component B containing propylene (PP4445S, Hostalen PP, PP8300G) at least 10 wt. hours and is a mixture of several polymers (PP1362R, Calprene 6120) with a density of 0.920 g / cm ³ , 30 wt. hours; component C is so much (determined by stoichiometry) that there is 0.5 wt.h in the final composition of maleic anhydride, dye - 50% carbon black concentrate in an amount of 5 wt. including a complex of stabilizers Tris (2,4-di-tert-butylphenyl) phosphite and disteryl thiodipropionate with their content in the final product - 0.8 wt. h. Component C is inoculated with maleic acid.

EXAMPLE 3

Composition: a monolayer composite thermoplastic coating contains component A with a density of 0.960 g / cm ³ 80 wt. hours; a mixture of polypropylene (PP4445S, Hostalen PP, PP8300G) and ethylene propylene monodiene (EPDM) (SKEPT-70, SKEPT-50, Keltan 5470P) 0.910 g / cm ³ with its content in the final product of 20 wt.h .; grafted ethylene copolymer (Metalen F-1018, Lotader 3210) onto which maleic anhydride (component C) is grafted in such a way that it is 98% by weight. ethylene accounts for 2 wt.%. maleic anhydride, to provide 0.4 parts by weight of maleic anhydride in the final composition, dye - 40% carbon black concentrate in an amount of 6 parts by weight, a complex of stabilizers, such as pentaerythrol tetrakis-3- (3,5-ditretbutyl-4 -hydroxyphenyl) propionate; tris (2,4-di-tert-butylphenyl) phosphite and disteryl thiodipropionate with their content in the final product of 0.1-0.8 wt.h.

EXAMPLE 4

A monolayer composite thermoplastic coating containing component A - alpha-olefin with 2 carbon atoms (Solen EP 0.26 / 5IN, Tipelin 7100M) and component B block copolymer and ethylene-propylene rubber (PP4445S, Hostalen PP, PP8300G, SKEPT-70, SKEPT -50, Keltan 5470P with a density of 0.880 g / cm ³ with a content of 28 parts by weight in the final product; component C is grafted with maleic anhydride (maleic anhydride 0.38 mass parts), dye - 45% carbon black concentrate in an amount of 7 parts by weight of the complex 2,6-di-tert-butyl-para-cresol and disteryl thiodipropionate with their content in the final product of 0.3 parts by weight

EXAMPLE 5

A monolayer composite thermoplastic coating containing component A is a comonomer with 1-butene, 1-pentene or 1-hexene (in different examples 6, 7, 8) (Solen EP 0.26 / 51N, Tipelin 7100M, Solen 13/56) and component B is a block copolymer with ethylene-propylene rubber (PP4445S, Hostalen PP, PP8300G, SKEPT-70, SKEPT-50, Keltan 5470P) with a density of 0.880 g / cm ³ and its content in the final product is 28 parts by weight; component C is grafted with maleic anhydride (maleic anhydride 0.38 wt. h), dye - 45% carbon black concentrate in an amount of 7 wt. parts, a complex of 2,6-di-tert-butyl-para-cresol and disteryl thiodipropionate with their the content in the final product of 0.11 wt.h.

In all examples, the application was carried out in this way: the outer surface of the pipes was cleaned of grease and subjected to blasting and abrasive cleaning to a degree of at least Sa 2 ½ according to ISO 8501-1, roughness up to 100 μm according to ISO 8503-4. Dustiness of the surface (by the number of dust particles) corresponded to reference prints 1-2 according to ISO 8502-3. The salt content on the outer surface is 10 mg / m ² according to ISO 8502-9. The cleaned surface is subjected to visual inspection to detect surface defects (scuffing, delamination, foam, sharp protrusions, deposited metal droplets) and the cleaned pipe surface is subjected to chromating.

Example 9. No surface chromating was performed. The pipes are heated to a temperature of 200 ° C. Any of the known epoxy primers is applied and a layer of the Metalen PE-21 coating according to the present invention is applied to the epoxy-coated steel pipe. The melt temperature at the outlet of the extruder to 240 ° ^C. A two-layer coating for protection of metallic surfaces, consisting of a layer of powdered epoxy primer, e.g., famous brands such as Eurokote 712RR, EP Aqua 20, P-EP-0130, Flywheels Nero-9005 and etc., and the claimed composite thermoplastic coating.

Claims (5)

1. A monolayer composite thermoplastic coating containing at least one homo- or copolymer of ethylene and / or ethylene-propylene rubber (component A) with a density of 0.940-0.980 g / cm ³ containing 50-90 parts by weight in the final product;
at least one propylene homo- or copolymer (component B), such as a block copolymer of polypropylene, polypropylene, a mixture of polypropylene and ethylene propylene monodien (EPDM) or ethylene propylene rubber with a density of 0.860-0.920 g / cm ³ containing 10 in the final product -30 parts by weight;
a homo- or copolymer of grafted ethylene which is grafted with a functional monomer, such as a carboxylic acid or its derivative, so that 98 wt.% of ethylene accounts for 2 wt.% of the carboxylic acid or its derivative, to provide 0.1 in the final composition -0.5 wt.h,
dye - 40-50% carbon black concentrate in an amount of 5-8 wt. hours
a complex of stabilizers such as pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate; 2,6-di-tert-butyl-para-cresol; tris (2,4-di-tert-butylphenyl) phosphite; disteryl thiodipropionate with their content in the final product of 0.1-0.8 wt.h. 2. The monolayer coating according to claim 1, characterized in that component C is grafted with a functional monomer, such as a carboxylic acid or its derivative such as maleic acid. 3. The monolayer coating according to claim 1, characterized in that preferably component A is high density polyethylene (HDPE) or a mixture of high density polyethylene, component B contains propylene of at least 10 parts by weight and is a mixture of several polymers or contains EPDM, and component C is grafted with maleic anhydride. 4. The monolayer coating according to claim 1, characterized in that preferably component A is an alpha olefin with 2-30 carbon atoms. 5. The monolayer coating according to claim 3, characterized in that component A is a comonomer with 1-butene, 1-pentene or 1-hexene.