CN115612372A - A kind of RB epoxy resin cured product and preparation method thereof - Google Patents

Abstract

The invention relates to a RB epoxy resin condensate which is a two-component coating and consists of a component A and a component B according to the mass ratio of 1-8, wherein the component A consists of a common epoxy resin composition, elastic epoxy resin and a solvent 1; the component B consists of an amine curing agent and a solvent 2, an isocyanate group elastic prepolymer group is blocked by epoxy propanol or methyl epoxy propanol to synthesize elastic resin with an epoxy group, the elastic resin is physically blended with common epoxy resin, and after the amine curing, the elastic epoxy resin and the common epoxy resin have two structural synergistic effects, so that the toughening modification of an epoxy cured product is realized. The RB epoxy resin condensate prepared by the method can adjust the elongation at break of 100-220%, simultaneously ensures that the tensile strength can meet the requirement of being adjustable at 10-20 MPa, solves the problem of poor flexibility of the condensate to a great extent, has flexibility and rigidity, and can be applied to the use environment in a wide temperature range.

Description

A kind of RB epoxy resin cured product and preparation method thereof

technical field

The invention relates to the field of coatings, in particular to a cured RB epoxy resin and a preparation method thereof.

Background technique

Due to its chemical structure containing a large number of polar functional groups and small volume shrinkage during curing, epoxy resin has good adhesion on a variety of metal substrates, ceramics, glass, and concrete surfaces; in addition, epoxy Resin has the characteristics of high strength, good medium resistance, and outstanding alkali resistance, and is often used as a film-forming material for heavy-duty anti-corrosion coating systems. However, due to its relatively high hardness, it is difficult for the molecular chain to rotate after the resin is cured, resulting in a large internal stress of the cured product, so the impact resistance and flexibility of the epoxy resin are relatively poor. The toughening of epoxy cured products often has the following methods: 1. Toughening a better curing agent by selecting flexibility; 2. Adding a linear reactive diluent for flexibility; 3. Adding a hydrocarbon resin for toughening Soft; 4. Rubber or polyurethane modified toughening. The above toughening or flexibilization methods can all improve the flexibility of the cured epoxy resin to a certain extent, and are currently the most commonly used solutions on the market.

The above-mentioned toughening or flexibilization methods can improve the flexibility of the cured epoxy resin to a certain extent, but the degree of toughening improvement is limited. Generally, the tensile strength of cured epoxy resin can be above 30MPa, but its elongation at break is only about 10%; the elongation at break of cured epoxy resin after toughening modification is only about 40%, However, the tensile strength after toughening modification is only about 2-5 MPa. At present, epoxy resin is toughened by grafting hydroxyl and isocyanate on the side chain of epoxy resin. This toughening method is to carry out toughening modification on the side chain structure of cured epoxy resin The toughening effect on the epoxy resin cured product is limited, the introduction amount is small, and the effective toughening effect cannot be achieved, and the introduction amount is large, and the strength loss is great. Therefore, although several toughening methods commonly used at present improve the elongation at break of cured epoxy resins, they have limited improvement in flexibility and seriously affect the bulk strength of cured epoxy resins. Therefore, it is necessary to toughen the cured epoxy by other means.

Contents of the invention

The research purpose of the present invention is to block the isocyanate-based elastic prepolymer group by glycidol or methylglycidol to synthesize an elastic resin with epoxy groups, and then perform physical Blending, after the amines are cured, the two structures of the elastic epoxy resin and the ordinary epoxy resin have a synergistic effect, and the toughening modification of the epoxy cured product is realized.

The present invention prepares a cured product of RB epoxy resin. The coating is a two-component coating composed of components A and B with a mass ratio of 1:1 to 8:1. The component A is composed of a common epoxy resin composition , Elastic epoxy resin, solvent 1 composition; B component is composed of amine curing agent, solvent 2 composition.

Further, the A component is composed of the following components in parts by weight:

Ordinary epoxy resin composition 15-45 parts

Elastic epoxy resin 15-45 parts

Solvent 1 15～45 parts

Said component B is composed of the following components in parts by weight:

Amine curing agent 6~34 parts

Solvent 2 6-79 parts.

Further, the elastic epoxy resin resin consists of the following components in parts by weight:

The epoxy compound is a kind of in glycidol or methylglycidol;

Put linear diols, polyols, and xylenes with a number average molecular weight of 500-3000 into the reaction bottle, raise the temperature to 130°C-135°C under the protection of an inert gas, reflux for dehydration for 1h-2h, and then cool down to 40°C-50°C ℃, add the formulated amount of diisocyanate, raise the temperature to 70°C for 2 hours, heat-retain for 2 hours, then raise the temperature to 85-95°C for 4h-8h, cool down to room temperature after the heat-retaining reaction, add the formulated amount of epoxy compound, and heat up again Heat the reaction at 70°C to 80°C for 6h to 9h, heat the reaction until the test shows -NCO% = 0, then cool down to room temperature, filter and discharge the material to obtain elastic epoxy resin

Further, the linear diol with a number average molecular weight of 500-3000 includes at least one of polyester diol, polyether diol, polytetrahydrofuran, polycarbonate diol, and polycaprolactone diol The polyol includes one of trimethylolpropane, glycerol, and pentaerythritol; the diisocyanate includes toluene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate at least one of

Further, the common epoxy resin composition comprises at least one of bisphenol A epoxy resin with a number average molecular weight of 350-7000 and novolac epoxy resin with a number average molecular weight of 320-480.

Further, the solvent 1 is at least one of xylene, methyl isobutyl ketone, methyl n-amyl ketone, and cyclohexanone; the solvent 2 is xylene, methyl isobutyl ketone, methyl n- At least one of amyl ketone and cyclohexanone; the amine curing agent is at least one of modified polyamide, modified alicyclic amine, and modified phenalkamine.

The second aspect of the present invention is to provide the preparation method of said a kind of RB epoxy resin cured product,

(1) The preparation method of the first component:

Add ordinary epoxy resin composition, elastic epoxy resin, and solvent into the tank according to the ratio, and stir evenly to obtain RB epoxy resin cured product A;

(2) The preparation method of the B component:

According to the ratio, add the amine curing agent and solvent into the tank, stir evenly, and then filter out the material to obtain Component B of RB epoxy resin cured product;

(3) Mix the components A and B according to the ratio to get the RB epoxy resin cured product.

The present invention directly synthesizes an elastic epoxy resin, all short bases are epoxy resin, and it is a multi-functional elastic epoxy resin. This epoxy resin is mixed with other common epoxy resins to finally obtain a high-strength epoxy resin. Tough epoxy cured. The toughening structural formula is aimed at toughening the main chain structure of the epoxy resin, and can play a good role in toughening and modifying the epoxy resin without reducing the strength.

The present invention can design and synthesize polyurethane prepolymer elastomers with different tensile strengths and elongations at break by adjusting the mass ratio of linear diols and polyols with different molecular weights, so that the tensile properties of this part of the prepolymer Adjustable; then react the -NCO functional group in the prepolymer with the hydroxyl group in the glycidyl alcohol or methyl glycidol molecule to synthesize an elastic resin containing epoxy functional groups whose tensile properties can be adjusted .

Ordinary bisphenol A type epoxy resin has high strength, but relatively poor flexibility. The synthetic elastic epoxy resin is mixed with ordinary epoxy resin, and then cured by amine curing agent. Elastic epoxy resin and ordinary epoxy resin The epoxy resin composition can be cross-linked to form a network macromolecule, so this RB epoxy resin cured product has both high strength and excellent tensile properties, which greatly improves the flexibility of ordinary epoxy cured products sex.

Beneficial effects of the present invention:

(1) In the present invention, the flexibility of the overall cured epoxy resin can be adjusted by adjusting the ratio of linear diols and polyols of different molecular weights;

(2) In the present invention, the rigidity of the cured epoxy resin can be adjusted by adjusting the ratio of the ordinary epoxy resin composition to the elastic epoxy resin.

(3) At present, the method of adjusting curing agent or adding active diluent and hydrocarbon resin to increase flexibility can only improve the flexibility of cured epoxy resin to a certain extent (the elongation at break is 70-100%), and the The strength of the cured epoxy resin has a great influence (tensile strength 2-5MPa); if rubber or polyurethane is used to modify toughened epoxy, the strength of the cured product is slightly higher (tensile strength 6-9MPa), but it does not improve the flexibility. Ideal (elongation at break 30-50%). The elongation at break of the cured RB epoxy resin prepared by the method of the present invention can be adjusted from 100% to 220%, and the tensile strength can be adjusted to 10 to 20 MPa at the same time. The present invention ensures the body strength of the cured epoxy At the same time, it solves the problem of poor flexibility of the cured product to a great extent, and has both flexibility and rigidity; the epoxy resin cured product prepared by the method of the present invention solves the problem of high brittleness of the epoxy resin cured product at low temperature, and can It is applied in a wide temperature range use environment.

detailed description

The present invention will be further described below in conjunction with specific examples, but not limited to the contents in the description.

Embodiment one:

(1) 77 parts of number-average molecular weights are 1000 polyester diols, 62 parts number-average molecular weights are 2000 polyester diols, 13 parts of trimethylolpropane, 102 parts of xylenes are added in the reaction flask, Under the protection of inert gas, heat up to 130°C-135°C, reflux for dehydration reaction for 2 hours, then cool down to 40°C, add 89 parts of toluene diisocyanate, heat up to 70°C for 2 hours, then heat up to 95°C for 6 hours, After the heat preservation reaction, cool down to room temperature, add 45 parts of methylglycidol, heat up again to 70°C-80°C for 8 hours, measure NCO%=0, cool down to room temperature, filter and discharge, and obtain elastic epoxy resin 1 .

(2) 30 parts of number-average molecular weights are 380 bisphenol A type epoxy resins, 15 parts of synthetic elastic epoxy resins 1, 20 parts of xylene, 10 parts of cyclohexanone are added in the tank, stirred evenly, and obtained A component 1 of cured RB epoxy resin.

(3) Add 33 parts of modified polyamide and 7 parts of xylene into the tank, stir evenly, a kind of RB epoxy resin cured product B component 1.

(4) The mass ratio between A component 1 and B component 1 of an RB epoxy resin cured product is 2:1.

Embodiment two:

(1) Add 268 parts of polyether diol with a number average molecular weight of 3000, 11 parts of trimethylolpropane, and 279 parts of xylene into the reaction flask, heat up to 130°C to 135°C under the protection of an inert gas, and reflux for dehydration React for 2 hours, then cool down to 40°C, add 94 parts of isophorone diisocyanate, raise the temperature to 70°C for 2 hours, then heat up to 95°C for 6 hours, cool down to room temperature after the heat preservation reaction, add 31 parts Glycidyl alcohol was heated again to 70°C to 80°C for 8 hours of heat preservation reaction, NCO%=0 was measured, the temperature was cooled to room temperature, and the material was filtered to obtain elastic epoxy resin 2.

(2) Add 15 parts of bisphenol A epoxy resin with a number average molecular weight of 6000 to 7000, 30 parts of synthetic elastic epoxy resin 2, 15 parts of cyclohexanone, and 30 parts of xylene into the tank, and stir evenly , to obtain a component 2 of RB epoxy resin cured product.

(3) Add 9 parts of modified polyamide and 21 parts of xylene into the tank, stir evenly, a kind of RB epoxy resin cured product B component 2.

(4) A RB epoxy resin cured product with a mass ratio of Component A 2 and Component B 2 is 3:1.

Embodiment three:

(1) Add 100 parts of polytetrahydrofuran with a number average molecular weight of 500, 14 parts of pentaerythritol, and 204 parts of xylene into the reaction flask, heat up to 130°C to 135°C under the protection of an inert gas, reflux for dehydration for 2 hours, and then cool down to 40°C, add 212 parts of 4,4'-dicyclohexylmethane diisocyanate, heat up to 70°C for 2 hours, then heat up to 95°C for 6 hours, cool down to room temperature after the heat preservation reaction, add 60 parts of epoxy Propanol, heated again to 70° C. to 80° C. and kept it warm for 8 hours, measured NCO% = 0, cooled to room temperature, filtered and discharged, and elastic epoxy resin 3 was obtained.

(2) 30 parts of bisphenol A type epoxy resins with a number average molecular weight of 1000, 15 parts of synthetic elastic epoxy resins 3, 15 parts of cyclohexanone, and 15 parts of methyl isobutyl ketone are added to the tank, and stirred Uniformly, to obtain a component 3 of RB epoxy resin cured product.

(3) Add 7 parts of modified phenalkamine and 8 parts of methyl isobutyl ketone into the tank, and stir evenly. A RB epoxy resin cured product B component 3.

(4) The mass ratio between A component 3 and B component 3 of a cured RB epoxy resin is 5:1.

A kind of RB epoxy resin cured product of Example 1-3 is mixed with component A and component B according to the corresponding ratio, and poured in the mold. After the cured product is cured, remove the sheet from the mold, and then put Bake and solidify in an oven at 100°C for 8 hours, then use the 1A cutter specified in GB/T 528 to cut the pieces, and perform a tensile performance test on a universal tensile testing machine at a rate of 100mm/min. The test results are shown in Table 1:

Table 1 Performance test table

Test items Embodiment one Embodiment two Embodiment three Tensile strength/MPa 13.72～15.84 10.37～13.10 16.74～19.28 Elongation at break/% 138～167 185～212 120～144

The present disclosure has been described by the above-mentioned related embodiments, but the above-mentioned embodiments are only examples for implementing the present disclosure. It must be pointed out that the disclosed embodiments do not limit the scope of the present disclosure. On the contrary, changes and modifications made without departing from the spirit and scope of the present disclosure all belong to the patent protection scope of the present disclosure.

Claims (7)

1. A cured RB epoxy resin material which is characterized by comprising: the epoxy resin composition is characterized by comprising a component A and a component B, wherein the component A and the component B are in a mass ratio of 1-8; the component B consists of an amine curing agent and a solvent 2.

2. The RB epoxy resin cured product according to claim 1, wherein: the component A comprises the following components in parts by weight:

15 to 45 portions of common epoxy resin composition

15 to 45 portions of elastic epoxy resin

1 to 45 portions of solvent

The component B comprises the following components in parts by weight:

6 to 34 portions of amine curing agent

And 6-79 parts of a solvent.

3. The RB epoxy resin cured product according to claim 1, wherein: the elastic epoxy resin comprises the following components in parts by weight:

the epoxy compound is one of epoxypropanol or methyl epoxypropanol;

putting linear dihydric alcohol with the number average molecular weight of 500-3000, polyol and dimethylbenzene into a reaction bottle, heating to 130-135 ℃ under the protection of inert gas, performing reflux dehydration reaction for 1-2 h, then cooling to 40-50 ℃, adding diisocyanate with the formula amount, heating to 70 ℃, performing heat preservation reaction for 2h, then heating to 85-95 ℃, performing heat preservation reaction for 4-8 h, cooling to room temperature after the heat preservation reaction is finished, adding epoxy compound with the formula amount, heating to 70-80 ℃ again, performing heat preservation reaction for 6-9 h, performing heat preservation reaction until-NCO% =0 is obtained through test, cooling to room temperature, filtering and discharging to obtain the elastic epoxy resin.

4. The cured RB epoxy resin according to claim 3, wherein: the linear dihydric alcohol with the number average molecular weight of 500-3000 comprises at least one of polyester dihydric alcohol, polyether dihydric alcohol, polytetrahydrofuran, polycarbonate diol and polycaprolactone diol; the polyalcohol comprises one of trimethylolpropane, glycerol and pentaerythritol; the diisocyanate comprises at least one of toluene diisocyanate, isophorone diisocyanate and 4,4' -dicyclohexylmethane diisocyanate.

5. The RB epoxy resin cured product according to claim 1, wherein: the common epoxy resin composition is at least one of bisphenol A type epoxy resin with the number average molecular weight of 350-7000 and phenolic aldehyde type epoxy resin with the number average molecular weight of 320-480.

6. The RB epoxy resin cured product according to claim 1, wherein: the solvent 1 is at least one of xylene, methyl isobutyl ketone, methyl n-amyl ketone and cyclohexanone; the solvent 2 is at least one of xylene, methyl isobutyl ketone, methyl n-amyl ketone and cyclohexanone; the amine curing agent is at least one of modified polyamide, modified alicyclic amine and modified phenolic amine.

7. The method for producing a cured RB epoxy resin material according to any one of claims 1 to 6, wherein:

(1) The preparation method of the component A comprises the following steps:

adding the common epoxy resin composition, the elastic epoxy resin and the solvent into a pulling cylinder according to the proportion, and uniformly stirring to obtain a component A of the RB epoxy resin condensate;

(2) The preparation method of the component B comprises the following steps:

adding the amine curing agent and the solvent into a drawing cylinder according to the proportion, uniformly stirring, filtering and discharging to obtain a component B of the RB epoxy resin condensate;

(3) And mixing the component A and the component B according to the proportion to obtain the RB epoxy resin condensate.