CS233145B1 - Adduct containing primary and secondary amine groups - Google Patents

Abstract

The invention relates to the field of synthetic resins and hardeners. The technical problem of preparing a hardener for epoxy resins, which has greater resistance to carbonate formation, is solved. The essence of the invention is an adduct of acrylic acid esters and polyamines. The invention can be used in the production of composites and solvent-free coatings.

Description

The invention relates to adduK-tU. prepared by reaction of acrylic esters with polyamines ·

Pdyamine compounds have many uses, whether as hardeners of epoxy or polyisocyanate resins, components of anticorrosive compositions, emulsifiers and the like. Due to the relatively high volatility of polyamines and the toxicity of their vapors, different types of polyamine adducts with various alcinoids such as epoxides, isocyanates , acrylates, crotonates, lactams and the like · The vapor pressure of the hectares is substantially reduced, thus reducing the risk of toxic vapor attack, but the aiucts are generally of relatively high viscosity, insufficient film-forming properties and easily form carbonates with airborne carbon dioxide.

We have now found a novel adduct of acrylic acid esters with polyamines which does not have the above drawbacks and is suitable, for example, as a hardener of solvent-free epoxy lacquers. The adduct according to the invention contains primary and secondary amine groups, has a mean molecular weight of 200 to 2,000; 200 mg KOH / g and an equivalent weight of 38 to 270 is obtainable by the reaction of methyl or ethyl esters of acrylic acid with polymers of an average molecular weight of 60 to 250,

233,145 at a molar ratio of acrylic: polyaqine = 11.1 to 1.80.

The process for the preparation of the adduct consists in dropping into the present polyamine at a temperature of not more than 100 ° C acres of the substances while cooling and stirring. After the addition of the acrylate, the temperature of the reaction mixture is increased to 110 to 200 ° C, at which aminolysis of the methoxy or ethoxy acrylates takes place. The liberated methanol or ethanol is continuously distilled off from the reaction mixture.

Among the polyamines, polyathylene polyamines, polypropylene polyamines, hexamethylenediamine, trimethylhexamethylenediamine, polyamine mixtures, technical cuts from aminolysis of dichloroethane or dichloropropanes and the like are preferably used for the preparation of the adduct of the invention.

Adhesives based on cycloaliphatic polyamines, in particular diaminocyclohexane, diaminocyclomethane, isopropanol and the like, are used to prepare special hard and flexible lacquers.

The admixtures of the present invention are viscous liquids that are unrestrictedly miscible with conventional types of base and modified epoxy resins or polyisocyanates. They cure these resins at room or slightly elevated temperature, optionally in the presence of melting accelerators such as phenolocol compounds, organic acids and the like. Additions of a compound regulating rheological properties and surface activity are often used.

Example 1

To a sulfurizing flask equipped with a stirrer, reflux condenser and thermometer was charged 1,704 g of tetraethylenepentamine (9 moles) and added dropwise over 5 hours to 5 ° 1 of ethyl acrylate (5 moles), maintaining the reaction temperature below 80 ° C. the reaction mixture is heated to 150 ° C when ethanol evolution begins. Ethanol is distilled off through a descending condenser and the temperature is gradually raised to 170 ° C to maintain a uniform distillation of ethanol. After about 3 hours, the aminolysis is complete,

233 145

T & aA & ni. the mixture is cooled to 120 DEG C. and a pressure of 2.5 kPa is maintained for 30 minutes. The product is a viscous liquid having a viscosity of 3780 mPa · s / 25 ° C, an average molecular weight of 495, an amine number of 1 135 mg KOH / g, an equivalent weight of 4l, 23 *

100 g of low molecular weight epoxy resin 375 with an average molecular weight of 375 and an epoxy group content of 0.531 mol / 100 g is mixed with 21.9 g of adduct and 0.2 g of 40% butanolic melamine-formaldehyde resin solution. film thickness of 110 microns / tri. Tílm. is allowed to cure at room temperature and relative air humidity of 70% * The cured film is completely clear, without traces of veil *

Example 2

1718 g (7 moles) of tetrapropylenepentamine are introduced into the apparatus and 5θ1 g (5 moles) of ethyl acrylate are added dropwise with uniform stirring over 5 hours. After completion of the dropwise addition, the reaction mixture is heated to 155 ° C. up to 170 ° C * After reaching this temperature (about 3 hours), the reaction mixture is maintained at 170-172 ° C for a further 30 minutes, then cooled to 120 ° C and volatiles (3.5 kPa) are removed under reduced pressure. * The product is a semi-solid having an average molecular weight of 1,998, an amine number of 818 mg KOH / g and an equivalent weight of 64.00 *

200 g of a 50% toluene solution of a medium molecular epoxy resin containing 0.355 mol / 100 g of epoxy groups in the dry matter, mixed with 45 g of a 50% solution of the solids in toluene-isobutanol (3 * l) & brushed gets a smooth, shiny and clear £ ilm with no veil traces (room temperature, 70% relative humidity) ·

Example 3

To the apparatus described in Example 1, 541 g (9 moles) of ethylenediamine are introduced and, while stirring, 430 g (5 moles) of methyl acrylate are added dropwise over 2 hours and the reaction temperature is cooled down.

-ί233 145 maintained at 60 DEG C. * After přlkapu reaction mixture is heated to 120 to 130 ° C, when it begins to proceed with evolution of methanol Aninolýza * The temperature is slowly increased to about 150 ° ^C (about 2.5 hours), and this The reaction mixture was cooled to 100 ° C and kept under a pressure of 10 kPa for 30 minutes.

The product is a viscous liquid having a viscosity of 89P mPa.s / 25 ° C, an average molecular weight of 204, an amine number of 894 mg KOH / g and an equivalent weight of 38.86, 100 g, low molecular weight epoxy resins containing 0.535 mol / 100 g epoxy groups mixed with 20 , 8 g of adduct and the mixture is allowed to harden * The hardened material has a tensile strength of 45 »6 MPa, an elongation of 6.7% and an impact strength of 12.7 kJ / m · The cast surface is impeccable, without veil ·

Claims (1)

SUBJECT OF THE INVENTION The adduct contains primary and secondary amine groups having an average molecular weight of 200 to 2000, an amine number of 240 to 1200 and an equivalent weight of 38 to 20, obtainable by reacting methyl acrylate or ethyl acrylate with polyamines of average molecular weight 60 to 250 at a molar ratio. acrylate: polylylamine t 1: 1.16 to 1.80,