CS241736B1 - Cement based on epoxide resins modified by copolymer of acrylonitrile with butadiene - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to an epoxy resin adhesive which is modified by a butadiene-acrylonitrile copolymer.

Structural adhesives, especially those used in aviation, are subject to high requirements. At present, these construction adhesives are manufactured in the form of powder and achieve the following parameters:

Adhesive Epoxy 1001 - shear strength under tensile load according to ČSN 66 8510 at 20 ° C min 19 MPa.

Adhesive Komaxit 1141 or 1151 - tensile strength according to ČSN 66 8510 at 20 ° C from 30 MPa, at 80 ° C from 25 MPa.

The glue in the form of a powder is difficult to apply in a uniform layer and, moreover, has to be melted before gluing, which is technologically disadvantageous.

The higher mechanical values of the glued joints are achieved by using the epoxy resin adhesive with the acrylonitrile-butadiene copolymer according to the invention, which consists in that the adhesive consists of 60 to 95% by weight. from an epoxy resin formed by polycondensation of 3-chloropropane-1,2-oxide with di-2,2- (parahydroxyphenyl) propane having a molecular weight of 380 to 1,500 epoxy group contents of 0.56 to 0.19 eq / ΙΟΟ The glue further comprises 5 to 40% by weight of acrylonitrile-butadiene copolymers having a molecular weight of up to 7,000, wherein the amount of acrylonitrile in the copolymers is from 5 to 50% by weight, and the copolymer may preferably contain other functional groups in an amount. to about 20% of a molecular weight selected from the group consisting of mercapto-SH, hydroxyl-OH, carboxyl-COOH, amino-cyano NH2 and halogen, preferably bromine, the adhesive comprises a dicyandiamide hardener in an amount of 1 to 11 wt. a combination of an epoxy resin with a copolymer and optionally up to 2% by weight of a reaction catalyst which is laurylbenzyldimethylammonium bromide, or tetramethylthiurane disulfide, or N- (parachlorphephnyl) N, N'-dimethylurea.

The glued joints made with the adhesive according to the invention achieve the following mechanical values:

Shear strength under tensile load according to CSN 66 8510 at 20 ° C from 35 to 45 MPa, at 80 ° C from 25 MPa. Peel strength according to ČSN 66 8516 at 20 ° C from 4 to 8 Nmm ^-1 .

Depending on the composition of each component, we will get the following end products:

At less than 20 wt. the modifying components and the low molecular weight epoxy resins together give a brittle final mass, at a content of from 20 to 30; modifying components and low molecular weight epoxy resins will yield a tough material, but ηθ still suitable for film production, at a content of from 30 to 40% by weight. modifying components and low molecular weight epoxy resins obtain a film-forming mass with a content of from 40 to 50% by weight. modifying components and low molecular weight epoxy resins obtain a mass no longer suitable for the production of the film, but not yet a paste and at a content of over 50% by weight. modifying components and epoxy resins of low molecular weight yield a pasty mass. Example 1

An example of a paste consistency composition of 50 wt. modifying ingredients and curable at 165 ° C for 60 minutes:

Epoxy resin of mol.

1400 45 wt. parts

Epoxy resin of mol.

weight 380 50 wt. α, ω-polybutadiene acrylonitrildicarboxylic acid mol.

weight 3 330 and an acrylonitrile content of 30 wt. 5 wt. parts

Dicyandiamide 6.6 wt. parts

Laurylbenzyldimethylammonium bromide 0.7 wt. parts

Example 2

Example of adhesive composition in the form of foil containing 20 wt. modifying ingredients and curable at 170 ° C for 150 minutes:

Epoxy resin of mol. 1 400 Epoxy resin with mol. 900 Epoxy resin of mol. weight 380 α, ω-diaminopolybutadiene acrylonitrile with mol. wt.

330 and an acrylonitrile content of 30 wt. Dicyandiamide parts by weight parts by weight parts by weight parts 2.9 wt. parts

Example 3

Example of adhesive composition containing 30 wt. modifying ingredients and curable at 165 ° C for 60 minutes (pasty consistency):

Epoxy resin of mol. weight 900

Epoxy resin of mol. weight 380 α, ω-dihydroxypolybutadiene acrylonitrile with mol. weight 3 330 and an acrylonitrile content of 30 wt. Dicyandiamide Tetramethylthiuram Disulfide wt. parts by weight parts by weight parts

4.8 wt. parts 0.5 wt. parts

Example 4

Example of adhesive composition in the form of foil containing 40 wt. modifying ingredients and curable at 125 ° C for 45 minutes:

Epoxy resin of mol. weight 1400 35

Epoxy resin of mol. weight 900 25,, ω-dibromopolybutadiene acrylonitrile of mol. weight 3,300 and an acrylonitrile content of 30 wt. 40

Dicyandiamide 2

N- (parachlorophenyl) -N, N-dimethylurea 0.7 wt. parts by weight parts by weight parts by weight parts of mass parts

An adhesive of the above compositions is prepared by first melting and mixing the epoxy resin with the modifying component at 80 to 90 ° C in a mixer, then briefly mixing the hardener and optionally the catalyst (both in finely crushed form preferably in a ball mill) . The mixture thus prepared may still be rotated in a screw extruder, if necessary, and if the final product is to be a film, the mixture must still be rolled to the appropriate shape on a rolling machine.

The adhesive according to the invention can be used for joining construction materials, especially for joining some aircraft parts.

Claims (1)

SUBJECT An adhesive based on epoxy resins modified with an acrylonitrile-butadiene copolymer, characterized in that it contains from 60 to 95% by weight of acrylonitrile. epoxy resins formed by polycondensation of 3-chloropropane-1,2-oxide with di-2,2- (parahydroxyphenyl) -propane of mol. wt. 380 to 1500, an epoxy content of 0.5 to 0.19 eq / g, the adhesive further comprising 5 to 401 wt. % of an acrylonitrile-butadiene copolymer having a molecular weight of up to 7,000, wherein the amount of acrylonitrile in the copolymer is from 5 to 50 wt. and wherein the copolymer optionally contains other functional groups in an amount of up to 20% by weight of the mercapto, hydroxyl, carboxyl, amino and halogen atom, preferably bromine, of the present invention, further comprising 1 to 11 weight percent dicyandiamide hardener. % based on 100 wt.% of the epoxy resin / copolymer combination; and optionally up to 2 wt. a reaction catalyst which is laurylbenzyldimethylammonium bromide, or tetramethylthiurane disulfide, or N- (parachlorophenyl) -N ', N'-dimethylurea.