RU2119515C1 - Polymerizable composite material - Google Patents

Abstract

FIELD: protective coatings. SUBSTANCE: claimed material comprises methyl methacrylate, polybutyl methacrylate, polyisocyanate, perchlorovinyl resin, polymerization initiates, polymerization catalyst, amine and modifying additive. In order to prepare homogeneous corrosion-resistant coatings on large size units and engineering structures that operate in tropical climate, said material comprises modifying additive such as aliphatic multihydric alcohols or esters of said alcohols, and orthophosphoric acid or mixture of said alcohols and said phosphates of said alcohols, the ratio of said components being as follows (wt parts): 100 methyl methacrylate; 3-65 polybutyl methacrylate; 1-75 polyisocyanate; 0.1-50 perchlorovinyl resin; 1-15 polymerization initiator; 0.05-5 polymerization catalyst; 0.01-5 amine; and 0.1-15 modifying additive. EFFECT: improved properties of the polymerizable composite material. 3 cl, 2 tbl

Description

The invention relates to a qualitative and quantitative composition of polymerizable compositions based on methyl methacrylate, which are intended:
for applying mainly acid- and alkali-resistant and wear-resistant protective coatings on metal, reinforced concrete and concrete products such as:
- tanks for storing solutions of acids and alkalis,
- internal and external surfaces of pipelines for transportation and
- automobile and railway tanks and ship tanks for the transport of solutions of acids and alkalis;
as a basis for anti-corrosion and anti-fouling coatings of the bottoms and propellers of ships (preferably marine and particularly preferably of the "river-sea"type);
as the basis of corrosion-resistant electrical insulating protective coatings of galvanic baths, etc .;
as an adhesive or sealant, mainly for connecting metal products to each other or with concrete and for sealing (in particular, waterproofing) joints of metal, concrete and reinforced concrete structures.

 Coatings from (or based on) the proposed material can be applied both at the final stages of manufacturing or construction of the protected products or structures, and during their repair (including under water).

 Moreover, the proposed material can be used both directly as a varnish, and in combination with suitable predominantly finely divided fillers.

 As can be seen from the description of the scope, the need for materials according to the invention is massive.

 Accordingly, these materials must satisfy a set of systematically tightening difficult-to-compatible requirements.

Indeed, it is desirable that these materials:
firstly, they provided the greatest possible protective effect in specific application conditions;
secondly, they could be made from commercially available ingredients;
thirdly, they practically did not require energy consumption for curing the applied “raw” coatings.

 Separate fulfillment of these requirements does not present significant difficulties.

 Indeed, the well-known ability of oligoesters or mixtures of acrylic mono- and polymers, widely used as the basis of polymerizable composite materials, to cure at room temperature, and often at a significantly lower temperature (see, for example: US, patent 2452669, 1949; Baghdasaryan X S. Theory of radical polymerization. - M .: Publishing House of the USSR Academy of Sciences, 1959).

 Their high chemical resistance to the action of most inorganic and organic acids and alkalis is well known (see, for example: Polyakov KA Non-metallic chemically resistant materials. - M .: Goskhimizdat, 1950).

 However, to increase the weather-, water- and wear-resistance and to achieve other specific effects, fillers and / or reactive additives are usually introduced into the polymerized compositions, which can hardly be called anything other than exotic.

 For example, to increase the corrosion resistance of the finished coatings, from 10 to 100 mass parts (hereinafter, parts by weight) of glass flakes are introduced into the oligoester polymerizable compositions, the average thickness of which can be selected in the range of 0.5 - 5.0 microns, and the average diameter - in the range of 100-400 microns, or a mixture of 10-70 parts by weight these glass flakes with 10-150 wt.h. flake metal pigments (see US, patent 4363889).

 Obtaining such fillers is very laborious.

 Chemically resistant fillers such as mica-like iron oxide pigments (Carter E. Micaceous iron oxide pigment in high performance coating // POLVMER PAINT COLOR JOURNAL, 1986, v.176, N 4164, p.226, 228, 230, 232, 234).

 However, their use significantly increases the cost of corrosion-protected products or engineering structures and, therefore, is advisable only in cases where the possible losses from the failure of such products or structures exceed the cost of protection.

 Therefore, mainly the attention of manufacturers of materials for applying anti-corrosion coatings is directed to the development of such polymerizable materials that would satisfy the above set of requirements as fully as possible.

 Typically, these compositions, created with the participation of the author of the new invention proposed below, provided for the use of basalt scales and complex polymerizable complexes as filler (see, in particular, USSR patents 1825510, 1825511, 1825514, 1831870 and 1831871 and Russian patent 2028347).

 Of the polymerizable composite materials of this type, the closest to the proposed one is the reactive composition consisting of polymers, monomers, polymerization initiators and other active ingredients, known from the description of the invention "Water and crack resistant polymer composition" (USSR patent 1831870).

This polymerizable composition contains, by weight. hours:
Methyl Methacrylate - 100
Polybutyl methacrylate - 5-100
Polyisocyanate - 10-70
Perchlorovinyl resin - 0.1 - 50
Polymerization initiator - 0.1-10
Polymerization catalyst - 0.05-2
Divinylbenzene - 0.5-15
Diethanolamine maleate - 0.01-1.5
Amine - 0.1-5
This composition is very effective in the manufacture of materials for protective coatings of high heat resistance using as filler from 5 to 400 wt. including activated basalt scales. The increase in heat resistance was achieved using a complex modifying additive containing divinylbenzene as a crosslinking agent and diethanolamine maleate as a predominantly surfactant and, at the same time, as a means of partially blocking the chemical activity of the polyisocyanate.

However, even when taken in the form of varnish, that is, without filler, the known composition has the less viability, the higher the ambient temperature and the more actively used filler. So, at a temperature of the order of 18-25 ^o C its viability does not exceed 30 minutes

Further, since divinylbenzene is capable of intensive radical polymerization even at low temperatures (less than 0 ^o C), and diethanolamine maleate is poorly compatible with the main ingredients of the polymerizable composition and therefore cannot noticeably weaken the chemical activity of the polyisocyanate, insofar as the processes of crosslinking of the formed polymethylmethacrylate chains with divinylbenzene and the formation of polyurethane substantially independent of one another.

 As a result, it is difficult to form coatings of uniform quality in large-area (about 10 or more sq. M) products or structures.

 In connection with the foregoing, the invention is based on the task of improving the quality composition and changing the ratio of ingredients to create such a polymerizable composite material that, both in pure form and in the presence of an active filler, would provide more uniform corrosion-resistant coatings in quality on large-sized products and engineering structures primarily operated in tropical climates.

The problem is solved in that the polymerizable composite material for applying mainly protective coatings containing methyl methacrylate, polybutyl methacrylate, polyisocyanate, perchlorovinyl resin, a polymerization initiator, a polymerization catalyst, an amine and a modifying additive, according to the invention contains a modifying additive in the form of aliphatic polyhydric alcohols, or such alcohols and phosphoric acid, or a mixture of these alcohols and these phosphates of these alcohols, wherein said ingre Denti taken in the following ratio, wt. hours:
Methyl Methacrylate (MMA) - 100
Polybutylmethacrylate (PBMA) - 3-65
Polyisocyanate (PI) - 1-75
Perchlorovinyl Resin (PCS) - 0.1-50
Polymerization Initiator (IP) - 0.1-15
Polymerization catalyst (KP) - 0.05-5
Amine - 0.01-5
Modifying additive (MD) - 0.1-15
(the abbreviations indicated in parentheses are used hereinafter in the same meanings clear from the above text).

 These polyhydric alcohols, or their phosphates, or mixtures of such alcohols and their phosphates are well compatible with the other ingredients of the proposed polymerizable composite material, and their use, subject to the specified ratio, allows not only to effectively weaken the chemical activity of polyisocyanates and thereby significantly increase the viability of the composition as a whole, but also to obtain - by adjusting the curing rate - a three-dimensional structure of cross-linked polyurethane and linear macromolecules by Limethyl methacrylate, which are randomly distributed in the volume of polyurethane and serve as "fittings". Naturally, the proposed polymerizable composite material is suitable for obtaining coatings of uniform quality in large products or structures, and that such coatings can be made either in the form of varnish films or using arbitrary solid dispersed fillers.

 The first additional difference is that the polymerizable composite material according to the invention contains 2,4,6-triamino-1,3,5-triazine (melamine) as an amine.

 This amine appears to be the most effective means of controlling the curing rate (and, correspondingly, viability) of the proposed polymerizable composite material containing the modifying additive according to the invention (especially when phosphates of polyhydric alcohols are present in its composition). In addition, the use of this amine improves the heat and weather resistance of the protective coatings.

 The second additional difference is that the polymerizable composite material according to the invention as an amine contains a mixture of melamine and bis- (4-amino-3-chlorophenyl) methane (diameter-X).

 The specified mixture of amines in relation to the proposed polymerizable composite material is the most effective crosslinker of the polyisocyanate, almost completely blocking the isocyanate groups and, thereby, eliminating the appearance of gas inclusions inside the coatings and the interaction of the finished coating with oxygen and air moisture.

Further, the invention is illustrated:
specific examples of the composition of the proposed polymerizable material (see table. 1),
a description of the method of its manufacture,
coating examples and comparative test results.

 As can be seen from the table. 1, examples 1 and 8 relate to compositions in which the ratio of ingredients is outside the stated range; examples 2 and 7 - to compositions in which the ratio of ingredients corresponds to the boundaries of the claimed range; other examples specify ratios within the claimed range, and Example 9 relates to the best embodiment of the inventive concept of the USSR patent 1831870 and is given here for comparison.

 It is obvious that the tab. 1 specific ingredients in no way limit the ability to implement an inventive concept.

Really:
as polyhydric aliphatic alcohols, butanediol, tetrites of the L- or D-erythritol type and pentites of the L- or D-arabite type and their alkyl substituted derivatives, hexites, polyvinyl alcohol, etc .;
as esters of polyhydric aliphatic alcohols and phosphoric acid, phosphates of the alcohols listed in the previous paragraph can be used along with the above;
in addition to the indicated ones, other organic peroxides and hydroperoxides, diazoamino, azo and azothio compounds, tetrazenes, etc .;
as polymerization catalysts, along with the indicated can be used methylaniline, organic salts of ferrous iron, etc .;
as amines, commercially available tribenzyl- and dimethylbenzylamine can be used along with those indicated.

 The selection of specific ingredients of the indicated type in accordance with the inventive concept can be carried out by a specialist having ordinary knowledge in chemistry and polymer technology and ordinary experience in paint and varnish production.

A method of manufacturing the proposed polymerizable composite material in the General case includes three main stages:
at the first stage, a mixture of methyl methacrylate, polybutyl methacrylate, perchlorovinyl resin and a polymerization catalyst, an amine and a modifying additive selected for a particular case are prepared, for which:
- the calculated amounts of powdered polybutyl methacrylate and perchlorovinyl resin are mixed,
- the resulting mixture is dissolved in full methyl methacrylate (usually with stirring and, if necessary, to speed up the dissolution, at a temperature raised to 40-45 ^o C) and
- in the obtained viscous polymer solution, the calculated amounts of the selected polymerization catalyst, amine and modifying additive are added;
at the second stage, the calculated amount of polyisocyanate is added to the previously obtained mixture, and the reaction mixture is thoroughly mixed again and
at the final third stage, the polymerization initiator is introduced and the resulting reaction mixture is thoroughly mixed again to avoid local overheating.

The obtained polymerizable composite material can then be used in a manner known to specialists:
or as a varnish for applying protective coatings,
or as water-, acid- and alkali-resistant adhesive or sealant (including for repair work under water),
or as a binder for anti-corrosion and / or wear-resistant paints containing artificial pigments mainly from acid and alkali-resistant minerals such as basalt,
or as a binder for the production of plastics reinforced, for example with fibrous materials, for the manufacture of shell structures or for the repair of predominantly thin-sheet metal products (in particular deck decks and bulkheads of sea and river vessels).

 The mixture of ingredients obtained in the first stage can be stored for a long time (at least six months in a tropical climate) as part of the 1st composite material, and the polyisocyanate and the selected polymerization initiator in the required doses can be stored separately, respectively, as the 2nd and 3rd parts of the same material. Such parts may be mixed immediately prior to use. The specific compositions of these parts for any of these applications in accordance with the inventive concept can be selected by a chemist with ordinary work experience.

 Naturally, in cases involving the introduction of any dispersed fillers, their calculated amounts can be introduced either at the first stage of preparation of the polymerizable composite material (as an ingredient of its 1st part) or ex tempora.

 In the case of using fillers such as threads, bundles of filament fibers or threads, technical fabrics or knitwear, it is advisable to coat them (for gluing) or impregnate immediately before laying (or laying) on the protected surface (or form) using a fully prepared polymerizable composite material .

In accordance with formulations 1-8 and recipe 9 according to table 1, unfilled samples of the proposed polymerizable composite material and, accordingly, samples filled with basalt flakes of the polymerizable composite material prototype were made, namely:
for viability tests - in the form of freshly prepared in chemical glasses with a capacity of 150 ml of polymerizable compositions weighing 100 g each;
to determine the specific impact strength - in the form of bars cured for 10 days at room temperature with dimensions of 100 x 10 x 5 mm, respectively, in length, width and thickness;
for determination of adhesion to a metal substrate - in the form of adhesive layers cured for 10 days, a polymer mass with a thickness of about 80-100 μm between steel parts glued at the smaller ends, which had the form of stepped cylinders with a total length of 25 mm, a diameter of 35 mm and a thickness of 5 mm in the part used subsequently for clamping in a tensile testing machine, and with a diameter of 25 mm, in the rest;
to determine the corrosion rate in a 3% aqueous solution of sodium chloride - in the form of coatings from the test material with a thickness of about 0.8 mm, which occupy about half the area of each plate of mild steel with a length of 100, a width of 60 and a thickness of 3 mm;
for determination of heat resistance on a PAULIK-PAULIK-ERDY derivatograph (Hungary), in the form of microdoses (with an initial weight of up to 0.5 g each), samples filled in standard crucibles and cured for 10 days.

These samples were used for testing by the following methods:
viability was determined in a well-known way by the time that elapsed from the moment of introduction of the polymerization initiator into the proposed composition to the moment of gelation;
specific toughness was determined on a standard pendulum headstock (in particular according to GOST 4647-80 "Plastics");
adhesion to a metal substrate was determined on tensile testing machines (in particular, according to GOST 14760-69 "Method for determining the tensile strength");
the corrosion rate in a 3% aqueous solution of sodium chloride was determined in a laboratory setup that ensured the removal of electrochemical potentiodynamic curves with the subsequent calculation of the corrosion rate according to the formula well known to specialists (see, for example, Damaskin BB, Petri O.A. Electrochemistry. - M .: Higher school, 1987);
the heat resistance on the specified derivatograph was determined by continuously monitoring the mass of the samples as the temperature gradually increased at a speed of 6 ^o C / h.

 The results of comparative tests of the proposed and known composite materials, which are the arithmetic mean for standard series of samples, are presented in table. 2.

 The industrial applicability of the proposed polymerizable composite material mainly in tropical climates obviously follows from the data given in table. 2.

As can be seen from it, the viability of the proposed polymerizable composite material at 40 ^o C in one example reaches 45 minutes, and in the worst of the examples is not less than 25 minutes, while the known composition under the same conditions turns into a gel unsuitable for coating within 5 minutes. This creates the prerequisites for obtaining coatings substantially more uniform in the physicomechanical properties.

 Further, with a slight advantage in comparison with the known composition in terms of adhesive strength and heat resistance, the proposed composite material is significantly more resistant to impact and resistant in a corrosive environment.

Claims (2)

1. A polymerizable composite material for applying mainly protective coatings containing methyl methacrylate, polybutyl methacrylate, polyisocyanate, perchlorovinyl resin, a polymerization initiator, a polymerization catalyst, an amine and a modifying additive, characterized in that it contains a modifying additive in the form of aliphatic polyhydric alcohols or esters alcohols and phosphoric acid, or a mixture of these alcohols and these phosphates of these alcohols, and these ingredients are taken in the following Chenia, wt. hours:
Methyl Methacrylate (MMA) - 100
Polybutylmethacrylate (PBMA) - 3 - 65
Polyisocyanate (PI) - 1 - 75
Perchlorovinyl resin (PCS) - 0.1 - 50
Polymerization Initiator (IP) - 0.1 - 15
Polymerization catalyst (KP) - 0.05 - 5
Amine - 0.01 - 5
Modifying additive (MD) - 0.1 - 15
2. The material according to claim 1, characterized in that it contains 2,4,6-triamino-1,3,5-triazine (melamine) as an amine.  3. The material according to claim 2, characterized in that as the amine it contains a mixture of melamine and bis- (4-amino-3-chlorophenyl) methane.

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