WO2022211653A1

WO2022211653A1 - Method for producing an aqueous epoxy dispersion

Info

Publication number: WO2022211653A1
Application number: PCT/RU2020/000756
Authority: WO
Inventors: Ирина Анатольевна СТАРОВОЙТОВА; Антон Николаевич СЕМЕНОВ
Original assignee: Общество с ограниченной ответственностью "НАУЧНО-ПРОИЗВОДСТВЕННАЯ ФИРМА "РЕКОН"
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2022-10-06

Abstract

The invention relates to a method for producing an aqueous epoxy dispersion. The method for producing an aqueous epoxy dispersion includes preparing a suspension of a nanomodifier in an epoxy resin or a mixture of epoxy resin and an organic solvent; introducing doses of the nanomodified epoxy resin into an aqueous solution of surfactants; carrying out dispersion at a rate of 1000-4500 rpm for a period of 5-30 minutes, with the following weight ratio of ingredients: 100 pbw epoxy resin or mixture of epoxy resins; 0-30 pbw organic solvent; 5-22 pbw block copolymer of ethylene oxide and propylene oxide; 0-5 pbw alkyl polyethylene glycol ester (co-emulsifier); 0.001-0.05 pbw nanomodifier (carbon nanotubes); 40-80 pbw water. The technical result consists in optimizing the formulation and process parameters for the production of aqueous epoxy resin dispersions.

Description

METHOD FOR OBTAINING WATER EPOXY DISPERSION

Technical field

The invention relates to a method for producing an aqueous epoxy dispersion for use as a film-forming component of lubricants for inorganic (glass and basalt) and carbon fibers, a binder for protective-decorative and anti-corrosion paints, primers, water-dispersion coatings, etc.

Prior Art

A known method for producing an epoxy emulsion (RF patent N°2154081, C09D 163/02, C09D 5/02, published 08/10/2000), including the combination of epoxy resin with a non-ionic type emulsifier with a hydrophilic-lipophilic balance (HLB) of 14-20 and/or anionic emulsifier at 51-79°C, followed by a batch introduction of water. As a result, homogeneous emulsions are obtained that are used to obtain decorative and protective coatings, primers, etc., which have high weather resistance and corrosion resistance.

The disadvantages of the proposed method is a rather short period of possible storage (3-6 months) and predominantly large particle size.

A known method for producing an aqueous epoxy dispersion (RF patent Ns2365607, C09D 163/00, C09D 5/02, published 08/27/2009), which consists in the fact that the interaction of the epoxy component - A (a mixture of cycloaliphatic or aliphatic resin with aromatic epoxy resin) and aliphatic difunctional compound B, at a temperature of 50-90°C for E5 h in the presence of a catalyst (tertiary amine or dimethylamine) to reduce the content of epoxy groups in component A to 5-70% of the original amount. Next, component A is added to the interaction product, mixed, and then four equal portions of distilled water are added. The result is a stable emulsion that does not contain solvents.

A significant disadvantage of this solution is the complexity, complexity and multi-stage process of manufacturing the dispersion.

As the closest analogue, a method for obtaining an aqueous epoxy emulsion (RF patent N°2587091, C09D 5/02, C09D 163/00, C09D 163/02, published on 06/10/2016) was chosen by direct emulsification of low molecular weight epoxy resin (liquid) with epoxy equivalent weight up to 300 g/eq. in an aqueous solution of surfactants containing a polycarboxylate ester and a copolymer of ethylene oxide and propylene oxide, as well as additionally silica sol.

The disadvantages of the proposed method are the inability to use the method in the process of dispersion of medium and high molecular weight resins with a higher epoxy weight equivalent - accordingly, there is no possibility of controlling the degree of stickiness of the film of dried dispersions (films are sticky when dried); as well as the impossibility of obtaining aqueous emulsions with an average particle size controlled over a wide range (in particular, more than 0.6 μm).

Disclosure of invention

The objective of the invention is to develop a method for producing a stable aqueous epoxy dispersion with a particle size controlled over a wide range, containing epoxy groups, which, when used, allows interaction with lubricant components (in particular, with some silanes), with epoxy resin hardeners.

The technical result consists in optimizing the recipe and technological parameters for the manufacture of aqueous dispersions of epoxy resins, providing: uniformity, high colloidal chemical stability of dispersions, small particle size of the dispersed phase (high dispersion), long shelf life, increased interfacial adhesion strength between the fiber (with applied lubricant based on the developed film formers - aqueous dispersions of nanomodified epoxy resin) and thermosetting binders based on epoxy, polyester and vinyl ester resins in the manufacture of polymer composite materials.

The technical result is achieved by the fact that the method for producing an aqueous epoxy dispersion includes preparing a suspension of a nanomodifier, which is a multilayer carbon nanotubes, in an epoxy resin with an epoxy equivalent of 180 g/eq. up to 1000 g/eq. or mixtures of epoxy resin with an organic solvent in the case of semi-solid and solid epoxy resins; dosing nanomodified epoxy resin in an aqueous solution of surfactants selected from block copolymers of ethylene oxide and propylene oxide or mixtures thereof with alkylpolyethylene glycol ether with 28 moles of ethylene oxide; dispersion at 1000-4500 rpm, circumferential speed not less than 20 m/s for 5-30 minutes at the following mass ratio of components (wt.h):

Epoxy or epoxy mix 100

Organic solvent 0-30

Block copolymer of ethylene oxide and propylene oxide 5-22

Alkylpolyethylene glycol ether (co-emulsifier) 0-5

Nanomodifier (carbon nanotubes) 0.001-0.05

Water 40-80

To obtain aqueous dispersions of epoxy resins, the following components were used:

As an epoxy resin in the method, medium and high molecular weight epoxy resins with an epoxy equivalent molecular weight (EEW) from 180 to 1000 g / eq were used, for example, Russian resins under the trademarks ED-20, ED-16, ED-8 from FKP “Plant named after Ya.M. Sverdlov, imported resins under the trademarks Epikote 1002 from Hexion Inc. (formerly Momentive, USA), DER 331, DER 337, DER 671, DER 692 from ONp (formerly Dow Chemical), NPEL-128S, NPEL-134, NPEL-136, NPES-601, NPES- 602, NPES-603, NPES-604, NPES-605, NPES-901, NPES-902, NPES-903, NPES-904 from NanYa Plastics Co. (Taiwan), YD-011, YD-012 from Kukdo Chemical (South Korea), CHS-EPOXY 530, CHS-EPOXY 510, CHS-EPOXY 411, CHS-EPOXY 301, CHS-Epoxy 211, CHS-Epoxy 112 from "Spolchemie" (Czech Republic), etc.;

As nonionic surfactants - a block copolymer of ethylene oxide and propylene oxide with a content of polyoxyethylene units from 78 to 85 mass% and HLB above 14.0, as a co-emulsifier - alkyl polyethylene glycol ether with 28 moles of ethylene oxide and HLB about 18.0;

As an organic solvent - diacetone alcohol (Diacetone alcohol - DAA), propylene glycol methyl ether (methoxypropanol) (propylene glycol methyl ether - PGME), ethylene glycol propyl ether (2-propoxyethanol) (ethylene glycol propyl ether - EGPE).

The method provides for the production of storage-stable aqueous dispersions of low- and medium-molecular epoxy resins with a wide range of dry residue, fineness and viscosity, which ensure the formation of films of varying degrees of stickiness when applied to the fiber. The use of low- and medium-molecular epoxy resins, nanomodification, optimized modes for obtaining dispersions, the inclusion of an organic solvent and a co-emulsifier in a number of compositions made it possible to obtain film formers with an average particle size of 0.1 to 1.0 μm. The introduction of multilayer CNTs as a nanomodifier makes it possible to increase interfacial adhesion in the "fiber (with a lubricant based on a nanomodified film former) - epoxy binder" system. The organic solvent allows the epoxy resin to be combined with an aqueous solution of surfactants at lower temperatures (compared to their softening and flow temperature without the introduction of a solvent). It is preferable to use an organic solvent with a boiling point higher than the softening point of the epoxy resin by at least 30-40°C to minimize the harmful effects on production personnel and avoid intense evaporation.

The method for obtaining an aqueous epoxy dispersion according to the claimed invention includes: preparation of a nanomodifier suspension

(multiwalled CNTs) in epoxy resin with an epoxy equivalent (from 180 g/eq. to 1000 g/eq.) or a mixture of epoxy resin with an organic solvent (in the case of semi-solid and solid epoxy resins); dosing nanomodified epoxy resin into an aqueous solution of surfactants (block copolymer of ethylene oxide and propylene oxide or its mixture with alkyl polyethylene glycol ether with 28 moles of ethylene oxide); dispersion at a speed of 1000-4500 rpm (peripheral speed of at least 20 m/s) for 5-30 minutes.

The introduction of an organic solvent makes it possible to: dissolve semi-solid and solid epoxy resins and ensure their processing at lower temperatures (compared to their softening point); obtain more finely dispersed systems (with a smaller average particle size); to ensure an increase in the manufacturability of the process - on average, the time of mixing the components during emulsification is reduced by 20-30%; increase the stability of the dispersion of medium molecular weight epoxy resins.

The block copolymer of ethylene oxide and propylene oxide is mixed with water and, in a number of compositions, with alkyl polyethylene glycol ether with 28 moles of ethylene oxide, after which epoxy resin or its mixture is introduced into the prepared aqueous surfactant solution with solvent. When preparing a solution of emulsifiers, distilled water with a temperature of +16 to +35 °C is used (preferably, from +18 to +30 °C).

After the introduction of all components, dispersion is carried out at a speed of 1000-4500 rpm (peripheral speed should be at least 20 m/s, preferably from 25 to 40 m/s) for 5-30 minutes. The viscosity of the resin/melt resin/solid resin solution (indicated in the examples) determines the processability of the dispersion process (a product with a higher viscosity is harder to pump and disperse at the specified rate). Reducing the circumferential velocity to 20 m/s or less will not allow obtaining a dispersion with a particle size of less than 1 μm).

EXAMPLES OF CARRYING OUT THE INVENTION

The following examples illustrate the invention. Examples 1-2.

A nanomodifier dispersion (multilayer CNTs) is preliminarily prepared in a liquid epoxy resin in the following ratio of components:

Epoxy resin - 100 m.h.

Nanomodifier (multilayer CNTs) - 0.001-0.01 m.h. The mixer (dissolver) is loaded with the calculated amount of a pre-prepared aqueous solution of surfactant (block copolymer of ethylene oxide and propylene oxide). Nanomodified epoxy resin is dosed into the surfactant solution with constant stirring. After the end of dosing, the mixture is dispersed at a speed of 2000-4000 rpm (but not less than 20 m/s) for at least 10 minutes until a homogeneous stable dispersion is obtained.

The ratio of components is shown in table 1.

Further, the dispersion can be diluted to 50-60% dry residue (mass fraction of non-volatile substances) and homogenized in a dissolver. When homogenizing in the volume of a dilute dispersion, the speed can be reduced to 1000 rpm.

Examples 3-8.

A solution of semi-solid or solid epoxy resin is preliminarily prepared in an organic solvent at a ratio of components:

Epoxy resin - 100 m.h. Organic solvent - 10-30 m.h.

Next, nanomodifier dispersions (multilayer CNTs) are prepared in a solution of epoxy resin or a mixture of epoxy resins in the following ratio of components: Epoxy resin diluted with an organic solvent - 110-130 m.h.

Nanomodifier (multilayer CNTs) - 0.005-0.05 m.h.

The mixer (dissolver) is loaded with the calculated amount of a pre-prepared aqueous solution of surfactant (a block copolymer of ethylene oxide and propylene oxide or a mixture of a block copolymer of ethylene oxide and propylene oxide with alkyl polyethylene glycol ether).

Nanomodified epoxy resin is dosed into the surfactant solution with constant stirring. After the end of dosing, the mixture is dispersed at a speed of 1500-4500 rpm (but not less than 20 m/s) for at least 5-7 minutes until a homogeneous stable dispersion is obtained. The ratio of components is shown in table 1.

Further, the dispersion can be diluted to 45-50% dry residue (mass fraction of non-volatile substances) and homogenized in a dissolver. When homogenizing in the volume of a dilute dispersion, the speed can be reduced to 1000 rpm. Table 1

Claims

CLAIM

A method for producing an aqueous epoxy dispersion, including the preparation of a suspension of a nanomodifier, which is a multilayer carbon nanotubes, in an epoxy resin with an epoxy equivalent of 180 g/eq. up to 1000 g/eq. or mixtures of epoxy resin with an organic solvent in the case of semi-solid and solid epoxy resins; dosing nanomodified epoxy resin in an aqueous solution of surfactants selected from a block copolymer of ethylene oxide and propylene oxide or its mixture with alkylpolyethylene glycol ether with 28 moles of ethylene oxide; dispersion at a speed of 1000-4500 rpm, peripheral speed of at least 20 m/s for 5-30 minutes at the following mass ratio of components (wt.h):

Epoxy or epoxy mix 100

Organic solvent 0-30

Block copolymer of ethylene oxide and propylene oxide 5-22

Alkylpolyethylene glycol ether (co-emulsifier) 0-5

Nanomodifier (carbon nanotubes) 0.001-0.05

Water 40-80