Anti-shedding epoxy resin adhesive and preparation method thereof

Abstract

The invention relates to an anti-shedding epoxy resin adhesive and a preparation method thereof, and belongs to the technical field of adhesives. The adhesive is prepared from the following raw materials in parts by weight: 50-60 parts of epoxy resin, 20-40 parts of a curing agent, 10-30 parts of a toughening agent, 1-5 parts of a coupling agent, 10-30 parts of starch modified epoxy resin, 1-5 parts of an anti-aging agent, 1-5 parts of an accelerant, 0.1-1 part of a defoaming agent, 0.1-1 part of a release agent and 10-20 parts of a diluent. The invention also discloses a preparation method of the adhesive. The adhesive prepared by the invention has excellent anti-falling performance, can effectively prevent an adhered object from falling off in the use process, and also has good water resistance, heat resistance and aging resistance.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to an anti-shedding epoxy resin adhesive and a preparation method thereof. Background Art

[0002] Epoxy resin is a widely used functional material with the characteristics of good adhesion, high mechanical strength, solvent resistance, corrosion resistance, and diverse processing. It plays an important role in chemical corrosion protection, electronic equipment, ship transportation, industrial bonding and other fields.

[0003] Epoxy resin adhesives have excellent mechanical properties, heat resistance, chemical resistance and electrical properties, and are widely used in aerospace, electronics, automobile manufacturing, construction and other fields. However, epoxy resin adhesives are prone to shedding during use, which seriously affects their use effect and life. Therefore, it is of great significance to develop an anti-shedding epoxy resin adhesive.

[0004] Starch is a natural high molecular polymer with the advantages of low price, wide source, and biodegradability. By modifying starch, a starch-modified epoxy resin with excellent performance can be prepared. The present invention applies the starch-modified epoxy resin to an anti-shedding epoxy resin adhesive to prepare an adhesive with excellent anti-shedding performance. Summary of the invention

[0005] The object of the present invention is to provide an anti-shedding epoxy resin adhesive and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an anti-shedding epoxy resin adhesive is made of the following raw materials in parts by weight: 50-60 parts of epoxy resin, 20-40 parts of curing agent, 10-30 parts of toughening agent, 1-5 parts of coupling agent, 10-30 parts of starch-modified epoxy resin, 1-5 parts of antioxidant, 1-5 parts of accelerator, 0.1-1 parts of defoaming agent, 0.1-1 parts of release agent, and 10-20 parts of diluent; the starch-modified epoxy resin is prepared by the following method:

[0007] (1) mixing starch with deionized water, stirring and reacting at 90-100° C. for 2-4 hours to obtain starch paste;

[0008] (2) cooling the starch paste to room temperature, adding sodium hydroxide solution to adjust the pH value to 8-10, then adding epichlorohydrin, stirring and reacting at 50-60° C. for 4-6 hours to obtain an intermediate product;

[0009] (3) adjusting the pH value of the intermediate product to neutral with hydrochloric acid, then washing with deionized water to neutrality, and drying to obtain a starch-modified epoxy resin;

[0010] The epoxy resin is at least one of BPA type epoxy resin, BPF type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, bisphenol S type epoxy resin, glycidyl amine type epoxy resin, hydantoin type epoxy resin, phenol formaldehyde varnish type epoxy resin, alicyclic epoxy resin and tea ring type epoxy resin.

[0011] Furthermore, the diluent is toluene:xylene:n-butanol prepared in a mass ratio of 5:1:1.

[0012] Furthermore, the curing agent is one or more of dicyandiamide, latent curing agent, and acid anhydride curing agent.

[0013] Furthermore, the toughening agent is one or more of carboxyl-terminated nitrile rubber, polysulfide rubber, and liquid nitrile rubber.

[0014] Furthermore, the coupling agent is one or more of silane coupling agent KH-550, silane coupling agent KH-560, and titanate coupling agent.

[0015] Furthermore, the antioxidant is one or more of antioxidant RD, antioxidant 4020, and antioxidant 4010NA.

[0016] Furthermore, the accelerator is one or more of accelerator DMP-30, accelerator M, and accelerator B.

[0017] Furthermore, the defoamer is one or more of an organosilicon defoamer, a polyether defoamer, and a mineral oil defoamer.

[0018] Furthermore, the release agent is one or more of zinc stearate, calcium stearate, and polyethylene wax.

[0019] Furthermore, the method for preparing the anti-shedding epoxy resin adhesive is characterized by comprising the following steps:

[0020] (1) adding epoxy resin, curing agent, toughening agent, coupling agent, starch-modified epoxy resin, antioxidant, accelerator, defoaming agent, release agent, and diluent into a reaction kettle, and stirring uniformly at 80-100° C. to obtain a mixture;

[0021] (2) vacuum degassing the mixture at 100-120° C. for 1-3 hours to obtain an anti-shedding epoxy resin adhesive.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0023] Epoxy resin refers to the general term for a class of polymers containing more than two epoxy groups in the molecule. Its structure contains epoxy groups, has good reactivity, can obtain good bonding force when combined with a curing agent, and endows the cured material with excellent physical and mechanical properties, heat resistance and electrical insulation properties, so the present invention uses epoxy resin as the base resin, and can improve the molding process, thermomechanical properties and bonding strength of the thermal conductive adhesive film by selecting epoxy resins with different structures and molecular weights. The present invention introduces starch groups into epoxy resins, so that the adhesive has excellent bonding force, while improving its biodegradability, and relies on coupling agents to effectively combine and compatibility with ordinary epoxy resins, and regulates the proportion of each raw material to achieve the maximized synergistic effect of each component, so that the adhesive prepared by the present invention has excellent anti-falling performance, can effectively prevent the adherend from falling off during use, and also has good water resistance, heat resistance, aging resistance, and high mechanical strength, and good bonding force for most materials. And low cost, high bonding strength, fast drying speed. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] The invention discloses an anti-shedding epoxy resin adhesive, which is prepared from the following raw materials in parts by weight: 50 parts of epoxy resin, 20 parts of curing agent, 10 parts of toughening agent, 1 part of coupling agent, 10 parts of starch-modified epoxy resin, 1 part of antioxidant, 1 part of accelerator, 0.1 part of defoaming agent, 0.1 part of release agent and 10 parts of diluent.

[0027] The starch-modified epoxy resin is prepared by the following method:

[0028] 1. Mix starch with deionized water, stir and react at 90°C for 2 hours to obtain starch paste;

[0029] 2. The starch paste was cooled to room temperature, sodium hydroxide solution was added to adjust the pH value to 8, and then epichlorohydrin was added, and the mixture was stirred at 50°C for 4 hours to obtain an intermediate product;

[0030] 3. The intermediate product is adjusted to a neutral pH value with hydrochloric acid, then washed with deionized water to a neutral pH value, and dried to obtain a starch-modified epoxy resin.

[0031] The curing agent is dicyandiamide.

[0032] The toughening agent is carboxyl-terminated nitrile rubber.

[0033] The coupling agent is silane coupling agent KH-550.

[0034] The antioxidant is antioxidant RD.

[0035] The accelerator is accelerator DMP-30.

[0036] The defoamer is an organosilicon defoamer.

[0037] The release agent is zinc stearate.

[0038] The diluent is toluene:xylene:n-butanol prepared in a mass ratio of 5:1:1.

[0039] A method for preparing an anti-shedding epoxy resin adhesive comprises the following steps:

[0040] 1. Add epoxy resin, curing agent, toughening agent, coupling agent, starch-modified epoxy resin, antioxidant, accelerator, defoamer, release agent and diluent into a reaction kettle, stir evenly at 80°C to obtain a mixture;

[0041] 2. The mixture was vacuum degassed at 100°C for 1 hour to obtain an anti-shedding epoxy resin adhesive.

[0042] Example 2

[0043] The invention discloses an anti-shedding epoxy resin adhesive, which is prepared from the following raw materials in parts by weight: 55 parts of epoxy resin, 40 parts of curing agent, 30 parts of toughening agent, 5 parts of coupling agent, 30 parts of starch-modified epoxy resin, 5 parts of antioxidant, 5 parts of accelerator, 1 part of defoaming agent, 1 part of release agent and 15 parts of diluent.

[0044] The starch-modified epoxy resin is prepared by the following method:

[0045] 1. Mix starch and deionized water, stir and react at 100°C for 4 hours to obtain starch paste;

[0046] 2. The starch paste was cooled to room temperature, sodium hydroxide solution was added to adjust the pH value to 10, and then epichlorohydrin was added, and the mixture was stirred at 60°C for 6 hours to obtain an intermediate product;

[0047] 3. The intermediate product is adjusted to a neutral pH value with hydrochloric acid, then washed with deionized water to a neutral pH value, and dried to obtain a starch-modified epoxy resin.

[0048] The curing agent is a latent curing agent.

[0049] The toughening agent is polysulfide rubber.

[0050] The coupling agent is silane coupling agent KH-560.

[0051] The antioxidant is antioxidant 4020.

[0052] The accelerator is accelerator M.

[0053] The defoamer is a polyether defoamer.

[0054] The release agent is calcium stearate.

[0055] The diluent is toluene:xylene:n-butanol prepared in a mass ratio of 5:1:1.

[0056] A method for preparing an anti-shedding epoxy resin adhesive comprises the following steps:

[0057] 1. Add epoxy resin, curing agent, toughening agent, coupling agent, starch-modified epoxy resin, antioxidant, accelerator, defoamer, release agent and diluent into a reaction kettle, stir evenly at 100°C to obtain a mixture;

[0058] 2. The mixture was vacuum degassed at 120°C for 3 hours to obtain an anti-shedding epoxy resin adhesive.

[0059] Example 3

[0060] The invention discloses an anti-shedding epoxy resin adhesive, which is prepared from the following raw materials in parts by weight: 60 parts of epoxy resin, 30 parts of curing agent, 20 parts of toughening agent, 3 parts of coupling agent, 20 parts of starch-modified epoxy resin, 3 parts of antioxidant, 3 parts of accelerator, 0.5 parts of defoaming agent, 0.5 parts of release agent and 20 parts of diluent.

[0061] The starch-modified epoxy resin is prepared by the following method:

[0062] 1. Mix starch and deionized water, stir and react at 95°C for 3 hours to obtain starch paste;

[0063] 2. The starch paste was cooled to room temperature, sodium hydroxide solution was added to adjust the pH value to 9, and then epichlorohydrin was added, and the mixture was stirred at 55°C for 5 hours to obtain an intermediate product;

[0064] 3. The intermediate product is adjusted to a neutral pH value with hydrochloric acid, then washed with deionized water to a neutral pH value, and dried to obtain a starch-modified epoxy resin.

[0065] The curing agent is an acid anhydride curing agent.

[0066] The toughening agent is liquid nitrile rubber.

[0067] The coupling agent is a titanate coupling agent.

[0068] The antioxidant is antioxidant 4010NA.

[0069] The accelerator is accelerator B.

[0070] The defoamer is a mineral oil defoamer.

[0071] The release agent is polyethylene wax.

[0072] The diluent is toluene:xylene:n-butanol prepared in a mass ratio of 5:1:1.

[0073] A method for preparing an anti-shedding epoxy resin adhesive comprises the following steps:

[0074] 1. Add epoxy resin, curing agent, toughening agent, coupling agent, starch-modified epoxy resin, antioxidant, accelerator, defoamer, release agent and diluent into a reaction kettle, stir evenly at 90-100°C to obtain a mixture;

[0075] 2. The mixture was vacuum degassed at 110°C for 2 hours to obtain an anti-shedding epoxy resin adhesive.

[0076] Comparative Example 1

[0077] Compared with Example 1, Comparative Example 1 is different in that no starch-modified epoxy resin is contained.

[0078] Comparative Example 2

[0079] Comparative Example 2 is different from Example 1 in that the preparation method of starch-modified epoxy resin is different, as follows:

[0080] 1. Mix starch with deionized water, stir and react at 90°C for 2 hours to obtain starch paste;

[0081] 2. The starch paste was cooled to room temperature, sodium hydroxide solution was added to adjust the pH value to 8, and then epichlorohydrin was added, and the mixture was stirred at 50°C for 4 hours to obtain an intermediate product;

[0082] 3. The intermediate product is adjusted to a neutral pH value with hydrochloric acid, then washed with deionized water to a neutral pH value, and dried to obtain a starch-modified epoxy resin.

[0083] Comparative Example 3

[0084] Compared with Example 1, Comparative Example 3 is different in that no coupling agent is contained.

[0085] Comparative Example 4

[0086] The difference between Comparative Example 4 and Example 1 is that the amount of the coupling agent used is 0.01 parts.

[0087] Performance Test:

[0088] The anti-shedding epoxy resin adhesives prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests according to GB / T 7124-2008. The test results are shown in Table 1.

[0089] Table 1 Performance test results

[0090]

[0091]

[0092] As can be seen from Table 1, the tensile strength, elongation at break, shear strength and anti-shedding performance of the anti-shedding epoxy resin adhesives prepared in Examples 1-3 are better than those of the anti-shedding epoxy resin adhesives prepared in Comparative Examples 1-4. This is because starch-modified epoxy resins and coupling agents are added in Examples 1-3, and the starch-modified epoxy resins and coupling agents work synergistically to improve the performance of the adhesive; Comparative Example 1 does not contain starch-modified epoxy resins, resulting in a decrease in the performance of the adhesive; the preparation method of the starch-modified epoxy resin in Comparative Example 2 is different, resulting in a decrease in the performance of the adhesive; Comparative Example 3 does not contain a coupling agent, and the coupling agent can improve the compatibility between the starch-modified epoxy resin and the epoxy resin and improve the performance of the adhesive; the amount of the coupling agent in Comparative Example 4 is 0.01 parts, and the amount is too small, resulting in a decrease in the performance of the adhesive.

[0093] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An anti-shedding epoxy resin adhesive, characterized in that: The invention is prepared from the following raw materials in parts by weight: 50-60 parts of epoxy resin, 20-40 parts of curing agent, 10-30 parts of toughening agent, 1-5 parts of coupling agent, 10-30 parts of starch-modified epoxy resin, 1-5 parts of antioxidant, 1-5 parts of accelerator, 0.1-1 parts of defoaming agent, 0.1-1 parts of release agent and 10-20 parts of diluent; the starch-modified epoxy resin is prepared by the following method: (1) mixing starch with deionized water, stirring and reacting at 90-100° C. for 2-4 hours to obtain starch paste; (2) cooling the starch paste to room temperature, adding sodium hydroxide solution to adjust the pH value to 8-10, then adding epichlorohydrin, stirring and reacting at 50-60° C. for 4-6 hours to obtain an intermediate product; (3) adjusting the pH value of the intermediate product to neutral with hydrochloric acid, then washing with deionized water to neutrality, and drying to obtain a starch-modified epoxy resin; The epoxy resin is at least one of BPA type epoxy resin, BPF type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, bisphenol S type epoxy resin, glycidyl amine type epoxy resin, hydantoin type epoxy resin, phenol formaldehyde varnish type epoxy resin, alicyclic epoxy resin and tea ring type epoxy resin.

2. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The diluent is toluene:xylene:n-butanol prepared in a mass ratio of 5:1:

1.

3. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The curing agent is one or more of dicyandiamide, latent curing agent and acid anhydride curing agent.

4. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The toughening agent is one or more of carboxyl-terminated nitrile rubber, polysulfide rubber, and liquid nitrile rubber.

5. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The coupling agent is one or more of silane coupling agent KH-550, silane coupling agent KH-560 and titanate coupling agent.

6. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The antioxidant is one or more of antioxidant RD, antioxidant 4020, and antioxidant 4010NA.

7. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The accelerator is one or more of accelerator DMP-30, accelerator M and accelerator B.

8. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The defoamer is one or more of an organosilicon defoamer, a polyether defoamer, and a mineral oil defoamer.

9. The anti-shedding epoxy resin adhesive according to claim 1, characterized in that: The release agent is one or more of zinc stearate, calcium stearate and polyethylene wax.

10. A method for preparing an anti-shedding epoxy resin adhesive according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) adding epoxy resin, curing agent, toughening agent, coupling agent, starch-modified epoxy resin, antioxidant, accelerator, defoaming agent, release agent, and diluent into a reaction kettle, and stirring uniformly at 80-100° C. to obtain a mixture; (2) vacuum degassing the mixture at 100-120° C. for 1-3 hours to obtain an anti-shedding epoxy resin adhesive.

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