RU2266935C1 - Coating composition - Google Patents

Abstract

FIELD: polymers, in particular resin compositions based on liquid hydrocarbon rubber useful in building industry for manufacturing of roofing and insulating coatings.

SUBSTANCE: claimed composition contains law molecular rubber isoprene-butadiene copolymer in monomer ratio of 20:80, having molecular weight of 3000-3500 and hydroxyl content of 0.7-1.1 mass %; polyisocyanate, waste from polycaproamide production, catalyst for urethane formation. Additionally composition may contain component moisture absorber, filler, plasticizer solvent, law molecular alcohol, antiaging agent pigment and surfactant.

EFFECT: coatings with decreased moisture absorption and increased aging resistance.

2 cl, 2 tbl

Description

The invention relates to polymer compositions based on liquid hydrocarbon rubbers intended for the installation of roofing and insulation coatings in construction.

Known composition for coatings, including copolymers of butadiene and piperylene with a molecular weight of 1200-3200 and 500-1200, glycerin, polyisocyanate, a urethane formation catalyst and rubber crumb (patent RF 1229214, MKI C 09 D 3/72, 1984).

The disadvantage of the coating of this composition is a fairly high water absorption.

Known composition for coatings, including low molecular weight butadiene-piperylene rubber with a molecular weight of 1200-3200, glycerol polyisocyanate, a urethane formation catalyst, hydroxylated rubber crumb and calcium oxide (RF patent 2024564, C 09 D 109/00, 1994).

The disadvantage of this composition is the high water absorption due to the wide molecular weight distribution and low functionality of butadiene-piperylene rubber.

A known composition for coatings, including butadiene-piperylene rubber, glycerin, polyisocyanate, a urethane formation catalyst, calcium oxide, chalk, an antioxidant is a product of the polymerization of isoprene production waste from the decomposition stage of 4,4-dimethyldioxane-1,3 (RF patent 1775447, С 09 D 109/00 . 1990).

The disadvantage of this composition is the increased water absorption.

The closest solution to the proposed invention by technical essence is a coating composition (RF patent 2186812, С 09 D 109/00, 2000), including a copolymer of butadiene with isoprene with a monomer ratio of 70:30, a molecular weight of 4000-5000, and a content of hydroxyl groups of 0 , 75-0.89 wt.%, Plasticizer, mineral filler, trifunctional low molecular weight alcohol, polyisocyanate, urethane formation catalyst, 2,4,6-tri-tert-butylphenol and ethyl silicate of the following composition, wt.h .:

Butadiene and Isoprene Copolymer 100 Plasticizer 5-30 Mineral filler 90-150 Trifunctional low molecular weight alcohol 1-5 Polyisocyanate 12-24 Urethane Catalyst 0.01-1.0 2,4,6-Tri-tert-butylphenol 0.5-1.5 Ethyl silicate 0.8-1.6

The disadvantages of this composition are higher water absorption and lower resistance to aging. Increased water absorption is due to the structure and monomer composition of rubber. Due to the wide molecular weight distribution of the rubber used, the content of non-functional and monofunctional macromolecules that are not involved in structure formation and create a defective cross-linked structure during curing of the composition is high.

The objective of the proposed technical solution is to create a composition with reduced water absorption, higher aging resistance.

The technical result is to reduce water absorption and increase resistance to aging.

The technical result is achieved in that the coating composition comprising low molecular weight rubber, polyisocyanate, a urethane formation catalyst, characterized in that it contains isoprene-butadiene copolymer as a low molecular weight rubber at a monomer ratio of 20:80, a molecular weight of 3000-3500, with a hydroxyl group content 0.7-1.1 wt.%, And the composition further comprises polycaproamide production wastes in the following ratio of components, parts by weight:

Low molecular weight rubber 100 Polyisocyanate 10-36 Polycaproamide Production Wastes 0.5-40 Urethane Catalyst 0.001-3.0

The coating composition additionally contains a component for moisture absorption, a filler, a plasticizer, a solvent, low molecular weight alcohol, an antioxidant, a pigment, a surfactant.

The essence of the invention lies in the use as a basis of the composition of low molecular weight hydroxyl-containing rubber PDI-1K with a narrow molecular weight distribution, therefore, higher functionality and a more perfect distribution according to the type of functionality, in particular a lower content of non- and monofunctional macromolecules due to the higher proportion of bifunctional macrochains. This provides a more dense and uniform grid of the cured coating composition, which leads to a decrease in water absorption. Polycaproamide production wastes are low molecular weight impurities separated by extraction with hot water from the polymer, followed by evaporation of the resulting solution. This is a mixture of oligocaproamides (89-94%), cyclic oligomers (1-3%) and ε-caprolactam (5-8%).

Due to the presence of polar groups (amine, amide, carboxyl) in the polycaproamide production wastes, the aging resistance and the adhesion of the composition to various materials (concrete, steel) increase. Polyisocyanate, reacting with amine and amide waste groups, forms additional crosslinking, thereby improving the rate of water absorption. However, the use of more than 40 parts by weight polycaproamide production waste in the composition leads to a sharp decrease in physical and mechanical properties.

The introduction of the urethane catalyst less than 0.001 wt.h. impractical due to the long curing time of the coating composition. An increase of more than 3.0 parts by weight reduces the pot life of the composition.

The decrease in the number of polyisocyanate less than 10 parts by weight leads to the formation of a weakly crosslinked structure and the formation of a gel-like product. The increase over 36 parts by weight impractical due to the tendency to foaming during curing.

Low molecular weight PDI-1K rubber is a copolymer of isoprene with butadiene with a butadiene content of 80% (TU 38. 103342-88), obtained by solution polymerization on a lithium catalyst using a trialkyl aluminum polymerization regulator. It has the following characteristics: molecular weight 3000-3500, the content of hydroxyl groups 0.7-1.1 wt.%, Viscosity at 25 ° C 2.9-3.4 Pa.s, glass transition temperature minus 64 ° C, density 900 kg / m ³ , the proportion of bifunctional macromolecules reaches 75%.

Polymethylene-polyphenyl isocyanates based on 4,4-diphenylmethanediisocyanate (TU 6-03-375-75, 113-03-38-106-90, 113-03-603-86, 2224-152-04691277- 96) or their imported analogues: desmodur, suprasek 5005, voratex SD-100 of the company Nunstman Polyurethane, Belgium with the content of isocyanate groups of 29-32%.

Tertiary amines or organometallic compounds, for example triethylamine (GOST 9966-85), dimethylbenzylamine (TU 6-09-2974-78), tin dibutyldilaurate (TU 6-02-818-73) are used as a urethane catalyst.

As rheological modifiers, surfactants are used, for example, oleic or stearic acid or organopolysiloxane modifiers with the formula:

where R ₁ - alkyl, aryl, alkoxygroup with the number of carbon atoms up to 6;

R ₂ is hydrogen, alkyl, aryl groups with up to 6 carbon atoms;

n is chosen so that the molecular weight of the organopolysiloxane is 200-2000, for example, PES-5 polyethylsiloxane liquid; tetraethoxysilane (TU 6-00-5763445-14-90), ethyl silicate-32 (TU 6-02-895-86); ethyl silicate-40 (GOST 26371-84), which are ethyl esters of silicic acid and their mixtures with oligoethoxysiloxanes with a mass fraction of silicon dioxide of 25-42%, a density of 0.93-1.07 g / cm ³ .

The composition of the composition may be introduced components that do not affect the intended technical result, but give the coating material other advantages. For example, facilitating dispersion and reducing displacement time, in particular stearic acid, oleic acid, an organic diluent (white spirit).

For the manufacture of the composition, mixing equipment is used that ensures homogenization of the polyisocyanate and catalyst in rubber, dispersion of powdered fillers and pigments, dissolution of rubber in plasticizer or plasticizer, antioxidants and additives in rubber. The degree of milling of solid particles should not exceed 100 microns. In the industrial use of the composition, the polyisocyanate is supplied complete with the composition and introduced into it immediately before coating.

The invention is illustrated by the following example. 300 g of low molecular weight PDI-1K rubber, 60 g of polyisocyanate, 0.3 g of urethane formation catalyst (tin dibutyl dilaurate), 15 g of finely divided polycaproamide production waste was loaded into a mixer with a 1 L volume mixer, the mixture was stirred for 10 minutes. The resulting mass is poured onto molds and kept at a temperature not lower than 20 ° C for 3-5 days. The composition corresponds to example 1 in table 1.

Compositions comprising fillers and other additives, in accordance with the claims, are prepared as follows: a prescription amount of rubber, polycaproamide production waste, filler, pigments, antioxidants, and a moisture absorption component are loaded into the mixer. The mass is stirred for 2 hours, a plasticizer, a solvent, a low molecular weight alcohol and a urethane formation catalyst are added, and again stirred for 20 minutes. Then polyisocyanate is introduced into the mixer and mixed for 10 minutes. After applied to the mold for curing. Similarly, preparing the composition of the prototype.

Tests of the coating material are carried out in accordance with GOST 263-93, GOST 270-75, GOST 426-66.

The properties of the obtained coating samples are shown in table 2.

From the data of table 2 it can be seen that the use of the inventive isoprene-butadiene copolymer as a binder of low molecular weight rubber in combination with polycapramide waste, polyisocyanate and a urethane formation catalyst provides a coating with reduced water absorption and higher aging resistance than the prototype. The combination with a filler, a component of moisture absorption and organopolysiloxane modifiers enhances the effect of reducing water absorption. Also, coatings have higher physical and mechanical properties compared to the prototype.

Coatings from formulations 14-16 have the worst properties, which is associated with a deviation of the content of the components of the composition from the optimal.

Thus, the claimed composition for coatings has a reduced water absorption and increased resistance to aging.

Table 1 Name of components Composition, parts by weight Prototype Pat. RF 2186812 1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen 14 fifteen 16 1. A copolymer of isoprene and butadiene with a ratio of monomers of 20:80, mol. weighing 3000-3500 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 2. A copolymer of isoprene and butadiene with a ratio of monomers 30:70, mol. weighing 4000-5000 100 3. Filler: a piece of chalk 150 150 150 150 200 180 150 150 280 100 90 kaolin 100 100 barite 250 4. Plasticizer chloroparaffin HP-470 80 80 80 90 90 80 120 dioctyl phthalate thirty thirty White Spirit 10 5 5 netoxol oil 100 MP oil 90 5. Low molecular weight alcohol: glycerol 1 3 3 3 3 3 4 3 3 3 10 trimethylolpropane 2 3 1 triethanolamine 3 6. Polyisocyanate twenty twenty twenty 22 24 26 32 22 36 22 22 36 16 40 10 nine 12 7. Desiccant calcium oxide 5 twenty 10 10 10 10 fifteen 10 10 10 10 cement 10 10

1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen 14 fifteen 16 Prototype gypsum 10 10 8. Urethane catalyst 0.1 0.25 0.25 0.5 1,0 0.5 0.5 3.0 0.001 0.5 1,0 1,0 0.05 3,5 0.001 0,0005 0.01 9. Waste from polycaproamide production 1 10 10 5 10 twenty 40 10 5 10 fifteen 2 0.5 5 1 fifty 10. Pigment 5 1 0.5 10 5 5 11. Antioxidant: 2,6-Ditretbutyl-4-methylphenol 1 2 product 2246 1 0.5 2,4,6-Tritrebutyl-phenol 1,5 12. Organopolysiloxane Modifiers 1 1 0.5 5 1,5 1 6 13. Ethyl silicate 1,0 Notes:
1. In the compositions 1-4, 6, 7, 9, 10, 13, 15, 16 and the prototype used tin dibutyl laurate, in the composition 5,11,14-dimethylbenzylamine, in the composition of 8,12 - triethylamine.
2. In compositions 9, 10, pigment was used as a ferrous oxide, in composition 7 - pigment red grade 4C, in compositions 6, 12 - chromium oxide, and in composition 8 - phthalocyanine blue.
3. In compositions 1-4 and the prototype, a polyisocyanate based on 4, 4-diphenylmethanediisocyanate was used, in compositions 5-7, desmodur was used, in compositions 8-10, suprasec 5005 was used, and in compositions 11-16, Voratex SD-100.
4. Composition 8 used polyethylsiloxane liquid PES-5, composition 11 — tetraethoxysilane, composition 10 — ethyl silicate 32, composition 9, 14 — ethyl silicate 40, composition 5 — stearic acid, composition 6 — oleic acid.

table 2 The name of indicators Properties Prototype Pat. RF 2186812 1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen 14 fifteen 16 Shore A hardness, cu 42 47 fifty 63 66 61 47 70 73 70 65 75 62 38 53 10 42 Conditional strength, kg / cm ² 8 nine nine fifteen 16 14 8 23 21 17 17 twenty 22 8 12 2 8 Bounce Elasticity,% 40 53 58 45 45 44 40 45 35 36 40 40 42 thirty 32 8 thirty Strength Aging Coefficient 0.88 0.90 0.92 0.96 0.96 0.97 0.88 0.95 0.88 0.95 0.96 0.98 0.90 0.7 0.83 0.5 0.88 Water absorption,% 0.8 0.8 1,0 0.98 1,0 1,2 2.0 1,1 1,0 1,0 1,0 0.96 1,1 2.0 2.2 2,5 2.6

Claims (2)

1. Composition for coatings, including low molecular weight rubber, polyisocyanate, a urethane formation catalyst, characterized in that it contains as a low molecular weight rubber a copolymer of isoprene with butadiene at a ratio of 20:80 monomers of a molecular weight of 3000-3500, with a hydroxyl content of 0.7-1 , 1 wt.%, And the composition further comprises waste products of polycaproamide in the following ratio, wt.h .: Low molecular weight rubber 100 Polyisocyanate 10-36 Polycaproamide Production Wastes 0.5-40 Urethane Catalyst 0.001-3.0 2. The coating composition according to claim 1, characterized in that it further comprises a component for moisture absorption, a filler, a plasticizer, a solvent, a low molecular weight alcohol, an antioxidant, a pigment, a surfactant.