RU2534775C1 - Polyurethane coating composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: polyurethane coating composition contains oligoester, polyisocyanate based on 4,4'-diphenylmethane diisocyanate and a solvent. The oligoester used has the formula

, where R is a compound of formula

, n is an integer from 1 to 3, m is equal to 1 or 3, k is equal to 4 or 8. The oligoester has molecular weight of 1096-1760 and acid number of less than 1 mg KOH/g. The technical result of the invention is high heat-resistance of coatings, raising the initial decomposition temperature of the coatings by 24-64° and 50% mass loss by 52-102°C, as well as high hardness and tensile strength of the coatings.

EFFECT: invention improves environmental friendliness of the composition by reducing the amount of polyisocyanate used and reduces the setting time of the composition.

2 tbl, 9 ex

Description

The invention relates to compositions of film-forming compositions and can be used as a protective polyurethane coating for wood, concrete, glass, metal.

Known polyurethane coating composition containing polyoxypropylene triol with a molecular weight of 3000-5000, a polyisocyanate based on 4,4'-diphenylmethanediisocyanate, tin dibutyl dilaurate and a solvent, the composition further comprises diphenylol propane, and acetone as a solvent in the following ratio, wt.hp .:

polyoxypropylene triol with a molecular weight of 3000-5000 30-70 4,4'-diphenylmethanediisocyanate polyisocyanate 65-70 tin dibutyl dilaurate 0.1-0.2 diphenylol propane 70-30 acetone 125,

see RU Patent No. 2393189, IPC C09D 175/08, C08G 18/65, C08G 18/32, C08G 18/24, 2010.

The disadvantage of this composition is the low heat resistance.

The closest in technical essence is a polyurethane coating composition containing polyoxypropylene triol, a polyisocyanate based on 4,4'-diphenylmethanediisocyanate and ethyl acetate in the following ratio of components, parts by weight:

polyoxypropylene triol with a molecular weight of 3000-5000 one hundred 4,4'-diphenylmethanediisocyanate polyisocyanate 100-200 ethyl acetate 100-200,

see RU Patent No. 2073053, IPC C09D 175/08, 1997.

The disadvantage of this composition is the insufficient strength properties of the coatings, their low heat resistance, a long curing time of the composition and the high content of toxic polyisocyanate in the composition.

The objective of the invention is to obtain a polyurethane composition for coatings with increased strength and heat resistance with a lower content in the composition of polyisocyanate.

The technical problem is solved in that a polyurethane coating composition containing an oligoester, a polyisocyanate based on 4,4'-diphenylmethanediisocyanate and a solvent in which it contains an oligoester of the formula as an oligoester

where R is a compound of the formula

,

,

where R represents an integer from 1 to 3,

m represents an integer of 1 or 3,

k represents an integer of 4 or 8, with a molecular weight of 1096-1760 and an acid number of less than 1 mg KOH / g, in the following ratio, wt.h .:

oligoester with a molecular weight of 1096-1760 one hundred polyisocyanate based 4,4'-diphenylmethanediisocyanate 16-26 solvent 116-126

The solution to the technical problem allows to increase the heat resistance of coatings, the initial temperature of the decomposition of coatings increases by 24-64 ° C or 9.8-26%, the temperature of loss of 50% of the mass by 52-102 ° C or 16.1-31.6%, to increase the hardness coatings by 1.2-1.9 times, the tensile strength of coatings by 1.5-3.1 times, improve the environmental friendliness of the composition by reducing by 4-5 times the amount of input polyisocyanate, reduce the drying time of the composition by 36 times.

Characteristics of the substances used in the composition:

- complex oligoester of the General formula

where R is a compound of the formula

,

,

n represents an integer from 1 to 3,

m represents an integer of 1 or 3,

k represents an integer of 4 or 8,

as a component of a coating composition.

The indicated oligoester is obtained by polycondensation of 2,2-bis- [4- (2-hydroxyethoxy) phenyl] propane or 2,2-bis- [4- (2-hydroxytriethoxy) phenyl] propane and adipic or sebacic acid at a molar ratio of 2,2-bis- [4- (2-oxnetethoxy) phenyl] propane or 2,2-bis- [4- (2-hydroxytriethoxy) phenyl] propane and adipic or sebacic acid (1, 33-2): 1, respectively, and polycondensation is carried out at a temperature of 150-200 ° C with removal of the resulting water to an acid value of less than 1 mg KOH / g.

The yield of the target product is 99%; an amber-colored oligoester with a viscosity at 60 ° C of 1.0-1.5 Pa · s and a molecular weight of 1096-1760.

The IR spectra of the oligoester contain absorption bands at 1600 cm ^-1 , corresponding to stretching vibrations of the carbon-carbon bonds of the benzene ring; a band at 1180 cm ^-1 corresponding to an isopropyl group; absorption bands at 2970 cm ^-1 , characterizing the presence of methylene groups; an absorption band at 3380 cm ⁻¹ , corresponding to stretching vibrations of hydroxyl groups; there is a band at 1735 cm ^-1 corresponding to an ester carbonyl; there is a group of bands in the region of 1170-1225 cm ^-1 , corresponding to stretching vibrations of the carbon-oxygen bond.

Table 1 The starting components and properties of the oligoester The starting components, g, and properties of the oligoester 1 Laprol 3603-2-12 Examples of the claimed object 2 3 four 5 6 7 2,2-bis- [4- (2-hydroxyethoxy-ss) phenyl] propane - 99,4 74,2 - - 67.5 70.1 2,2-bis- [4- (2-hydroxy-ethoxy) phenyl] propane - - - 113.6 108,5 - - Sebacic acid - - - - - 32,5 29.9 Adipic acid - 30.6 25.8 16,4 21.5 - - n - 2 3 one 2 3 2 m - one one 3 3 one one k - four four four four 8 8 Synthesis temperature, ° C 100-150 180 200 160 200 220 180 Synthesis time, h twenty 21.5 28 53 36 24 31 Cf, mg KOH / g - 0.6 0.9 0.9 0.9 0.8 0.9 GP, mg KOH / g 46.9 95.8 69.6 101.5 65.1 63 87.1 Molecular weight calculated 3600 1168 1594 1094 1696 1762 1280 Molecular weight found 3590 1164 1591 1096 1699 1760 1275 Viscosity at 60 ° C, Pa · s at 25 ° C (500-650) -106 1,2 1.4 1,0 1,5 1,5 1.3

Based on the data of chemical analysis, including determination of the values of acid and hydroxyl numbers, as well as IR spectroscopy data, the claimed oligoester is an oligomer with terminal hydroxyl and carboxyl groups, containing ester, isopropyl groups and benzene rings inside the chain.

- a polyisocyanate based on 4,4'-diphenylmethanediisocyanate of the Surizon or Surizon P 85 trademark in accordance with TU 113-03-29-22-84;

- ethyl acetate according to GOST 8981-78;

- acetone according to GOST 2768-84 / 2;

- butyl acetate according to GOST 8981-78.

 Example 1 (prototype), parts by weight:

Polyoxypropylene triol of molecular weight 3600 (available under the brand name “Laprol-3600-2-12”, see TU 2226-015-10488057-94) 100 is loaded into a container with a stirrer, ethyl acetate 100 is added, stirred and polyisocyanate based on 4.4 is added Surizon 100 brand α-diphenylmethanediisocyanate is stirred for 3 hours until the content of NCO groups is at least 10%. The composition is applied to substrates of glass, metal, fluoroplastic.

Example 2 (according to the claimed object).

The polyurethane composition for coatings is obtained by mixing the components in the following ratio, parts by weight:

A molecular weight oligoester of 1164-100 is loaded into a container with a stirrer, a solvent is added, which is used as ethyl acetate 123, mixed and a polyisocyanate based on Surison 23,4'-diphenylmethanediisocyanate is added, stirred for 20 minutes until the content of NCO groups is at least 10 % The composition is applied to substrates of glass, metal, fluoroplastic.

Example 3

The composition is obtained analogously to example 2, but using a mixture of solvents.

Example 4

The composition is obtained analogously to example 2, but using an oligoester of molecular weight 1591.

Example 5

The composition is obtained analogously to example 2, but using an oligoester of molecular weight 1096.

Example 6

The composition is obtained analogously to example 2, but using an oligoester of molecular weight 1275.

Example 7

The composition is obtained analogously to example 2, but using an oligoester of molecular weight 1760.

Example 8

The composition is obtained analogously to example 2, but using a different solvent.

Example 9

The composition is obtained analogously to example 4, but using a different solvent.

The drying time of the composition is determined by the absence of adhesion of a sheet of paper to the film formed after applying the composition to a steel plate, GOST 19003-73.

The relative hardness of the coating on the glass plate (in arbitrary units) is determined in relation to the hardness of the glass on the pendulum device brand ME-3 according to GOST 5233-67.

Adhesion (in points) is determined by the method of trellised incisions of the coating on a metal plate according to GOST 15140-78.

The impact strength of a coating on a metal plate (Nm) is determined on a U-1A device according to GOST 4763-73.

The tensile strength of the film is determined on a tensile testing machine according to GOST 18299-72.

The thermal stability of the coatings is evaluated by the values of the initial decomposition temperature (T _beg ), and the temperature loss of 50% of the mass (T _50% ), determined according to thermogravimetric analysis at a heating rate of 2 ° C / min in accordance with GOST 29127-91.

According to the table given data of physical and mechanical testing of coatings, the claimed polyurethane composition can be used as a protective polyurethane coating for wood, concrete, glass, metal.

table 2 The data in examples 1-9 The composition, parts by weight, and coating properties 1 (prototype) Examples of the claimed object 2 3 four 5 6 7 8 9 Polyoxypropylene triol (Laprol 3600-2-12) one hundred - - - - - - - - Polyester - one hundred one hundred one hundred one hundred one hundred one hundred one hundred one hundred Polyisocyanate one hundred 23 23 eighteen 26 22 16 23 eighteen Ethyl acetate one hundred 123 - 118 126 122 116 - - Acetone - - fifty - - - - - - Butyl acetate - - 73 - - - - 123 118 Drying time, h 36 one one one one one one one one Hardness 0.43 0.8 0.8 0.6 0.3 0.8 0.5 0.8 0.6 Adhesion score one one one one one one one one one Impact strength, Nm 5 5 5 5 5 5 5 5 5 Tensile strength, MPa 19.7 61.6 61.6 59.1 29.8 42.1 40,4 61.6 59.1 Coating mass loss temperatures: T _beg. ° C 246 310 310 300 270 300 270 310 300 T _50% , ° C 323 380 380 375 405 425 420 380 375

As can be seen from the examples of a specific implementation, the claimed polyurethane composition allows to increase the heat resistance of coatings, the initial temperature of the decomposition of the coating increases by 24-64 ° C or 9.8-26%, the temperature of the loss of 50% of the mass by 52-102 ° C or 16.1- 31.6%, increase the hardness of coatings by 1.2-1.9 times, the tensile strength of coatings by 1.5-3.1 times, improve the environmental friendliness of the composition by reducing by 4-5 times the amount of introduced polyisocyanate, reduce the drying time composition 36 times.

Claims (1)

A polyurethane coating composition containing an oligoester, a polyisocyanate based on 4,4'-diphenylmethanediisocyanate, a solvent, characterized in that it contains an oligoester of the formula as an oligoester

,
where R is a compound of the formula

n represents an integer from 1 to 3,
m represents an integer of 1 or 3,
k represents an integer of 4 or 8,
with a molecular weight of 1096-1760 and an acid number of less than 1 mg KOH / g, in the following ratio of components, parts by weight:
oligoester with a molecular weight of 1096-1760 one hundred polyisocyanate based 4,4'-diphenylmethanediisocyanate 16-26 solvent 116-126