RU2444551C1 - Coating composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: composition contains low-molecular rubber - an isoprene and butadiene copolymer with monomer ratio 20:80, molecular weight 3000-3500 and 0.7-1.1 wt % content of hydroxyl groups, 4,4'-diphenylmethane diisocyanate, urethane formation catalyst, tin dibutyl dilaurate, glycerine, oxidised isotactic polypropylene with molecular weight 200000-700000.

EFFECT: improved dynamic and elastic-hysteresis properties.

2 tbl

Description

The invention relates to rubber coatings based on liquid hydrocarbon rubbers intended for the device of coatings mainly for sports fields, floors, 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 (RF patent 1229214, MKI C09D 3/72, 1984). The disadvantage of the coating of this composition are low dynamic and elastic hysteresis properties.

Known composition for coatings, including low molecular weight butadiene-piperylene rubber with a molecular weight of 1200-3200, glycerin, polyisocyanate, a urethane formation catalyst, hydroxylated rubber crumb and calcium oxide (RF patent 2024564, IPC C09D 109/00, 1994).

The disadvantage of this composition is the low dynamic and elastic hysteresis properties due to the wide molecular weight distribution and low functionality of butadiene-piperylene rubber.

A known coating composition, including butadiene-piperylene rubber, glycerin, polyisocyanate, a urethane formation catalyst, calcium oxide, chalk, an antioxidant is a product of polymerization of isoprene production waste - decomposition stage 4.4 of dimethyldioxane-1,3 (RF patent 1775447, IPC C09D 109/00, 1990).

The disadvantage of this composition is the low dynamic and elastic hysteresis properties.

A known coating composition comprising a copolymer of butadiene with isoprene with a monomer ratio of 70:30, a molecular weight of 4000-5000, a hydroxyl content of 0.75-0.89 wt.%, A plasticizer, a mineral filler, a trifunctional low molecular weight alcohol, polyisocyanate, a urethane formation catalyst 2,4,6-tri-tert-butylphenol and ethyl silicate (RF patent 2186812, IPC C09D 109/00, 2000).

The coating of this composition has low dynamic and elastic hysteresis properties.

The closest solution to the proposed invention in technical essence is a coating composition (RF patent 2266935, IPC C09D 109/00, C09D 175/14, 12/27/2005), including low molecular weight rubber, polyisocyanate, a urethane formation catalyst as a low molecular weight rubber, contains a hydroxyl-containing isoprene copolymer with butadiene with a monomer ratio of 20:80, an average molecular weight of 3000-3500, a hydroxyl content of 0.7-1.1 wt.% (PDI-1K) in the following ratio, wt.h .:

Isoprene and Butadiene Copolymer (PDI-1K) one hundred Polyisocyanate 10-36 Urethane Catalyst 0.001-3.0

The composition further comprises moisture absorption components, a filler, a plasticizer, a solvent, a low molecular weight alcohol, an antioxidant, a pigment, a surfactant.

The coating of this composition has insufficient strength and deformation due to the low level of dynamic and elastic hysteresis properties. This is due to the defectiveness of the three-dimensional structure of the mesh formed during curing. Therefore, the polymer network formed during curing of the rubber has a significant number of defects in the form of free ends that do not absorb the load under impact. In addition, the weak adhesive interaction at the interface of the polymer-mineral filler does not allow to obtain coatings with the required strength.

The objective of the invention is to increase the strength and deformation of the coatings.

The technical result is an increase in strength, dynamic and elastic hysteresis properties.

The technical result is achieved in that the coating composition, including low molecular weight rubber, a copolymer of isoprene with butadiene at a monomer ratio of 20:80, a molecular weight of 3000-3500, with a hydroxyl content of 0.7-1.1 wt.%, 4,4-diphenylmethanediisocyanate , the catalyst for urethane formation is tin dibutyl laurate, glycerin, additionally contains oxidized isotactic polypropylene of molecular weight 200000-700000 in the following ratio of components, parts by weight:

Low molecular weight rubber one hundred 4,4-diphenylmethanediisocyanate 12-36 Oxidized Isotactic Polypropylene 5-50 Tin Dibutillaurate 0.001-0.1 Glycerol 1-5

Due to the presence of functional groups in the oxidized isotactic polypropylene (hydroxyl, carboxyl, carbonyl and others), dynamic and elastic hysteresis properties increase. In addition, the resistance to aging, the adhesion of the composition to various materials (concrete, steel), dynamic and physico-mechanical properties are increased.

To obtain oxidized isotactic polypropylene (OIPP), a laboratory setup is used consisting of a column type oxidation reactor, an electric heater, and a bubbler.

Example 1. In the reactor serves 4.6 g of isotactic polypropylene grade HC 205 TF, having the following characteristics:

Molecular Weight, g · mol ^-1 342000 Melting point, ° С 165 Viscosity at 24 ° С, Pa · s 16.19

14 ml of ethylbenzene are poured into the reactor and heated to an oxidation temperature for one hour until the polypropylene is completely swollen. Excess ethylbenzene is removed and 1 ml of benzaldehyde is introduced into the system. The resulting homogeneous system is maintained at a temperature of 160 ° C and oxidized with atmospheric oxygen for two hours. The resulting OIPP weighing 8.5 g is removed from the reactor. It has the following indicators:

Molecular Weight, g · mol ^-1 90,000 Melting point, ° С 146 Viscosity at 24 ° С, Pa · s 4.8

Example 2. It is carried out analogously to example 1, but toluene is used as an aromatic hydrocarbon and oxidation is carried out at a temperature of 140 ° C for three hours. Received OIPP has the following indicators:

Molecular Weight, g · mol ^-1 85500 Melting point, ° С 141 Viscosity at 24 ° С, Pa · s 4.4

Example 3. It is carried out analogously to example 1, but p-xylene is used as an aromatic hydrocarbon and oxidation is carried out at a temperature of 150 ° C. Received OIPP has the following indicators:

Molecular Weight, g · mol ^-1 89000 Melting point, ° С 143 Viscosity at 24 ° С, Pa · s 4,5

The results of IR spectroscopy of oxidized isotactic polypropylene revealed the presence of intense absorption bands in the regions 3360-3720 and 1670-1725

cm ^-1 , which indicates the appearance in the spectrum of oxidized polypropylene of hydroxyl, carbonyl and carboxyl groups.

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%.

Tin dibutyl dilaurate (TU 6-02-818-73) is used as a catalyst for urethane formation.

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 are used as a polyisocyanate in the composition -96).

For the manufacture of the composition using mixing equipment, ensuring the homogenization of the polyisocyanate and the catalyst 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 rubber PDI-1K, 60 g of polyisocyanate (4,4-diphenylmethanediisocyanate), 0.3 g of a urethane formation catalyst (tin dibutyl dilaurate), 9 g of glycerol, 15 g of finely divided oxidized low molecular weight are loaded into a mixer with a 1 L volume mixer 1 liter the mixture is 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.

Other compositions of the prototype are similarly prepared, the compositions of which are shown in table 1.

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 a copolymer of isoprene with butadiene in combination with oxidized isotactic polypropylene, polyisocyanate (4,4-diphenylmethanediisocyanate), glycerin and a urethane formation catalyst (tin dibutyl dilaurate with a higher strength) provides a higher coating strength and provides a binder with a low molecular weight rubber and provides a higher coating strength than the prototype. Coatings from formulations 7-10 have the worst properties, which is associated with a deviation of the content of the components of the composition from the optimal.

The use of more than 50 parts by weight oxidized isotactic polypropylene in the composition leads to a sharp decrease in physical and mechanical properties, less than 5 parts by weight does not affect the properties of the composition.

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 0.1 parts by weight reduces the pot life of the composition.

The decrease in the number of polyisocyanate less than 12 wt.h. 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.

Thus, the claimed composition for coatings has enhanced dynamic and elastic hysteresis properties.

Table 1 Name of components Composition, parts by weight Prototype Pat. RF 2266935 one 2 3 four 5 6 7 8 9 10 1. A copolymer of isoprene and butadiene with a ratio of monomers of 20:80, mol. weighing 3000-3500 one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred 2. Filling: chalk 150 3. Plasticizer: chloroparaffin HP-470 80 4. Low molecular weight alcohol: glycerin 3 2 5 3 3 one 7 0.5 3 four one 5. Polyisocyanate: 4,4-diphenylmethane and isocyanate twenty fifteen 36 thirty 25 12 40 8 fifteen twenty twenty 6. Desiccant: cement 10 7. Urethane Catalyst: Tin Dibutyl Dilaurate 0.1 0.01 0.1 0.01 0.01 0.1 0.001 0.01 0.0001 0.2 0.5 8. Waste from polycaproamide production 35 9. Oxidized Isotactic Polypropylene 5 10 twenty thirty 40 fifty 55 60 65 3 10. Antioxidant: 2,6-Ditretbutyl-4-methylphenol one

table 2 The name of indicators The properties Prototype Pat. RF 2266935 one 2 3 four 5 6 7 8 9 10 1. Shore A hardness, cu 64 59 66 67 69 56 53 thirty 35 40 56 2. Conditional strength, kg / cm ² eighteen 17 19 19 twenty fourteen 10 12 8 5 12 3. Elongation at break,% 95 140 110 90 85 120 70 65 60 55 60 4. The rebound elasticity,% 45 44 40 53 45 42 fifty thirty 45 32 42

Claims (1)

Composition for coatings, including low molecular weight rubber in the form of a copolymer of isoprene with butadiene with a monomer ratio of 20:80 of a molecular weight of 3000-3500, with a hydroxyl content of 0.7-1.1 wt.%, 4,4′-diphenylmethanediisocyanate, a urethane formation catalyst - tin dibutyl dilaurate, glycerin, characterized in that the composition further comprises oxidized isotactic polypropylene of molecular weight 200000-700000 in the following ratio of components, parts by weight:
Low molecular weight rubber one hundred 4,4′-Diphenylmethanediisocyanate 12-36 Oxidized Isotactic Polypropylene 5-50 Tin Dibutyl Dilaurate 0.001-0.1 Glycerol 1-5