High-toughness and high-impact-resistance composite epoxy adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of adhesives, and particularly relates to a high-toughness and high-impact-resistance composite epoxy adhesive and a preparation method thereof.The preparation method comprises the following steps that S1, 10-30 parts of polyester polyol and 100 parts of epoxy resin are stirred at the temperature of 80-120 DEG C, and an epoxy resin prepolymer is obtained; step S2, uniformly mixing 100 parts of bismaleimide resin with 20 to 30 parts of an allyl compound, 10 to 15 parts of aminophenylacetylene, 30 to 50 parts of benzoxazine and 1 to 5 parts of an accelerant, and carrying out stirring reaction at 110 to 130 DEG C, so as to obtain a modified bismaleimide resin prepolymer; s3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer according to a mass part ratio of 100: (1-10), and adding an anhydride curing agent to obtain mixed resin; and S4, sequentially adding 1-5 parts of a stabilizer, 1-5 parts of an accelerant, 1-5 parts of a silane coupling agent and 20-40 parts of filler into the mixed resin, stirring at 60-80 DEG C, and cooling to obtain the high-toughness and high-impact-resistance composite epoxy adhesive.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a high-toughness and high-impact composite epoxy adhesive and a preparation method thereof. Background Art

[0002] Epoxy adhesives can be cured at room temperature and have excellent resistance to oil, water, acid, alkali, and organic solvents. They can bond to wet surfaces, oily surfaces, metals, plastics, ceramics, hard rubber, wood, etc.

[0003] Because epoxy adhesives contain a variety of polar groups and highly active epoxy groups, they have strong adhesion to polar materials, especially materials with high surface activity. At the same time, the cohesive strength of epoxy cured products is also very large, so their bonding strength is very high.

[0004] However, because epoxy resin forms a highly cross-linked three-dimensional network structure during the curing process, although this structure provides high strength and good bonding properties, it also leads to the brittleness and low toughness of the material, which in turn causes the toughness and impact resistance of the epoxy adhesive to be poor, making it difficult to meet the current adhesive requirements for the elongation and impact resistance of the material.

[0005] Therefore, how to overcome the brittleness and low toughness caused by the three-dimensional network structure formed by the curing of epoxy resin is a technical problem that needs to be solved urgently in this field.

[0006] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the invention

[0007] The embodiments of the present disclosure at least provide a high-toughness and high-impact composite epoxy adhesive and a preparation method thereof.

[0008] In the first aspect, the embodiment of the present disclosure provides a method for preparing a high-toughness and high-impact composite epoxy adhesive, comprising the following steps: step S1, stirring 10-30 parts of polyester polyol and 100 parts of epoxy resin at 80-120° C. to obtain an epoxy resin prepolymer; step S2, mixing 100 parts of bismaleimide resin with 20-30 parts of allyl compound, 10-15 parts of aminophenylacetylene, 30-50 parts of benzoxazine, and 1-5 parts of accelerator, and stirring at 110-130° C. Stirring the reaction to obtain a modified bismaleimide resin prepolymer; step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer in a mass ratio of 100:(1-10), and adding an anhydride curing agent to obtain a mixed resin; step S4, adding 1-5 parts of a stabilizer, 1-5 parts of an accelerator, 1-5 parts of a silane coupling agent and 20-40 parts of a filler to the mixed resin in sequence, stirring at 60-80° C., cooling, and obtaining a high-toughness and high-impact composite epoxy adhesive.

[0009] In an optional embodiment, the polyester polyol includes any one or more combinations of polyisophthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyisophthalic acid-3-methyl-1,5-pentanediol adipate diol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

[0010] In an optional embodiment, the epoxy resin includes at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0011] In an optional embodiment, the bismaleimide includes any one or more combinations of diphenylmethane bismaleimide, diphenyl ether bismaleimide, meta-phenylene bismaleimide and diphenyl sulfone bismaleimide.

[0012] In an optional embodiment, the allyl compound includes any one or more combinations of diallyl bisphenol A, diallyl bisphenol F, diallyl bisphenol S, bisphenol A bisallyl ether, o-diallyl bisphenol A diglycidyl ether and allyl phenol.

[0013] In an optional embodiment, the aminophenylacetylene includes any one or more combinations of o-aminophenylacetylene, m-aminophenylacetylene and p-aminophenylacetylene.

[0014] In an optional embodiment, the stabilizer includes any one or more combinations of barbituric acid, lactic acid, boric acid, benzoic acid, phenylacetic acid and benzoic acid.

[0015] In an optional embodiment, the accelerator includes any one or more combinations of imidazole, imidazole adducts, aromatic amines, aliphatic amines and urea substitutes.

[0016] In an optional embodiment, the filler includes any one or more combinations of mica powder, nano-silicon dioxide and nano-calcium carbonate.

[0017] In a second aspect, the embodiments of the present disclosure also provide a high-toughness and high-impact composite epoxy adhesive obtained by the preparation method as described above.

[0018] The beneficial effect of the present invention is that the high-toughness and high-impact composite epoxy adhesive and its preparation method are toughened by pre-polymerization of epoxy resin and polyester polyol, and the modified bismaleimide resin is added to perform second phase structure toughening. At the same time, the cross-linked network between the epoxy resin and the modified bismaleimide resin can appropriately reduce the rigidity of the adhesive and improve the impact resistance after curing.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below for detailed description as follows. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are 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.

[0022] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Therefore, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. On the contrary, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0023] In this document, as used herein, expressions such as "at least one of..." when following a list of elements modify the entire list of elements rather than modifying the individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0024] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limited. As used herein, the singular articles "one", "an" and "the" may also be intended to include plural forms, unless it is clearly indicated above that this is not the case. The terms "comprise", "include" and "have" are inclusive, and therefore specify the presence of features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or combinations thereof. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the specific order discussed or shown, unless specifically identified as an execution order. Additional or alternative steps may be adopted.

[0025] Some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0026] The embodiment of the present disclosure provides a method for preparing a high-toughness and high-impact composite epoxy adhesive, comprising the following steps: step S1, stirring 10-30 parts of polyester polyol and 100 parts of epoxy resin at 80-120° C. to obtain an epoxy resin prepolymer; step S2, mixing 100 parts of bismaleimide resin with 20-30 parts of allyl compound, 10-15 parts of aminophenylacetylene, 30-50 parts of benzoxazine, and 1-5 parts of accelerator, and stirring at 110-130° C. reaction to obtain a modified bismaleimide resin prepolymer; step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer in a mass ratio of 100:(1-10), and adding an anhydride curing agent to obtain a mixed resin; step S4, adding 1-5 parts of a stabilizer, 1-5 parts of an accelerator, 1-5 parts of a silane coupling agent and 20-40 parts of a filler to the mixed resin in sequence, stirring at 60-80° C., and cooling to obtain a high-toughness and high-impact composite epoxy adhesive.

[0027] In some embodiments, specifically, the polyester polyol includes any one or more combinations of polyisophthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyphthalic acid-3-methyl-1,5-pentanediol adipate diol, polyisophthalic acid-3-methyl-1,5-pentanediol adipate diol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

[0028] In some embodiments, specifically, the epoxy resin includes at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0029] In some embodiments, specifically, the bismaleimide includes any one or more combinations of diphenylmethane bismaleimide, diphenyl ether bismaleimide, meta-phenylene bismaleimide and diphenyl sulfone bismaleimide.

[0030] In some embodiments, specifically, the allyl compound includes any one or more combinations of diallyl bisphenol A, diallyl bisphenol F, diallyl bisphenol S, bisphenol A bisallyl ether, o-diallyl bisphenol A diglycidyl ether and allyl phenol.

[0031] In some embodiments, specifically, the aminophenylacetylene includes any one or more combinations of o-aminophenylacetylene, m-aminophenylacetylene and p-aminophenylacetylene.

[0032] Specifically, the terminal acetylene group and the benzene ring introduced by the aminophenylacetylene and the allyl compound respectively participate in the curing of bismaleimide to form an interpenetrating polymer network structure, thereby further improving the toughness of the adhesive.

[0033] In some embodiments, specifically, the acid anhydride curing agent includes any one or more combinations of tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0034] In some embodiments, specifically, the stabilizer includes any one or more combinations of barbituric acid, lactic acid, boric acid, benzoic acid, phenylacetic acid and benzoic acid.

[0035] In some embodiments, specifically, the accelerator includes any one or more combinations of imidazole, imidazole adduct, aromatic amine, aliphatic amine and urea substitute.

[0036] In some embodiments, specifically, the filler includes any one or more combinations of mica powder, nano-silicon dioxide and nano-calcium carbonate.

[0037] The disclosed embodiments also provide a composite epoxy adhesive with high toughness and high impact resistance obtained by the preparation method as described above.

[0038] Example 1

[0039] A method for preparing a high-toughness and high-impact composite epoxy adhesive comprises the following steps:

[0040] Step S1, stirring 15 parts of polyisophthalic acid-3-methyl-1,5-pentanediol adipate and 100 parts of bisphenol A epoxy resin at 100° C. to obtain an epoxy resin prepolymer;

[0041] Step S2, mixing 100 parts of diphenylmethane bismaleimide, 20 parts of diallyl bisphenol A, 10 parts of o-aminophenylacetylene, 30 parts of benzoxazine, and 2 parts of 1-methylimidazole, and stirring the mixture at 120° C. to obtain a modified bismaleimide resin prepolymer;

[0042] Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer at a mass ratio of 100:1, and adding tetrahydrophthalic anhydride to obtain a mixed resin;

[0043] Step S4, adding 1 part of benzoic acid, 1 part of 1-methylimidazole, 2 parts of KH-550 and 30 parts of nano-silicon dioxide to the mixed resin in sequence, stirring at 60° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

[0044] Example 2

[0045] A method for preparing a high-toughness and high-impact composite epoxy adhesive comprises the following steps:

[0046] Step S1, stirring 15 parts of polyisophthalic acid-3-methyl-1,5-pentanediol adipate and 100 parts of bisphenol A epoxy resin at 100° C. to obtain an epoxy resin prepolymer;

[0047] Step S2, mixing 100 parts of diphenylmethane bismaleimide, 20 parts of diallyl bisphenol A, 10 parts of o-aminophenylacetylene, 30 parts of benzoxazine, and 2 parts of 1-methylimidazole, and stirring the mixture at 120° C. to obtain a modified bismaleimide resin prepolymer;

[0048] Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer at a mass ratio of 100:2.5, and adding tetrahydrophthalic anhydride to obtain a mixed resin;

[0049] Step S4, adding 1 part of benzoic acid, 1 part of 1-methylimidazole, 2 parts of KH-550 and 30 parts of nano-silicon dioxide to the mixed resin in sequence, stirring at 60° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

[0050] Example 3

[0051] A method for preparing a high-toughness and high-impact composite epoxy adhesive comprises the following steps:

[0052] Step S1, stirring 15 parts of polyisophthalic acid-3-methyl-1,5-pentanediol adipate and 100 parts of bisphenol A epoxy resin at 100° C. to obtain an epoxy resin prepolymer;

[0053] Step S2, mixing 100 parts of diphenylmethane bismaleimide, 20 parts of diallyl bisphenol A, 10 parts of o-aminophenylacetylene, 30 parts of benzoxazine, and 2 parts of 1-methylimidazole, and stirring the mixture at 120° C. to obtain a modified bismaleimide resin prepolymer;

[0054] Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer at a mass ratio of 100:5, and adding tetrahydrophthalic anhydride to obtain a mixed resin;

[0055] Step S4, adding 1 part of benzoic acid, 1 part of 1-methylimidazole, 2 parts of KH-550 and 30 parts of nano-silicon dioxide to the mixed resin in sequence, stirring at 60° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

[0056] Example 4

[0057] A method for preparing a high-toughness and high-impact composite epoxy adhesive comprises the following steps:

[0058] Step S1, stirring 15 parts of polyisophthalic acid-3-methyl-1,5-pentanediol adipate and 100 parts of bisphenol A epoxy resin at 100° C. to obtain an epoxy resin prepolymer;

[0059] Step S2, mixing 100 parts of diphenylmethane bismaleimide, 20 parts of diallyl bisphenol A, 10 parts of o-aminophenylacetylene, 30 parts of benzoxazine, and 2 parts of 1-methylimidazole, and stirring the mixture at 120° C. to obtain a modified bismaleimide resin prepolymer;

[0060] Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer in a mass ratio of 100:7.5, and adding tetrahydrophthalic anhydride to obtain a mixed resin;

[0061] Step S4, adding 1 part of benzoic acid, 1 part of 1-methylimidazole, 2 parts of KH-550 and 30 parts of nano-silicon dioxide to the mixed resin in sequence, stirring at 60° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

[0062] Example 5

[0063] A method for preparing a high-toughness and high-impact composite epoxy adhesive comprises the following steps:

[0064] Step S1, stirring 15 parts of polyisophthalic acid-3-methyl-1,5-pentanediol adipate and 100 parts of bisphenol A epoxy resin at 100° C. to obtain an epoxy resin prepolymer;

[0065] Step S2, mixing 100 parts of diphenylmethane bismaleimide, 20 parts of diallyl bisphenol A, 10 parts of o-aminophenylacetylene, 30 parts of benzoxazine, and 2 parts of 1-methylimidazole, and stirring the mixture at 120° C. to obtain a modified bismaleimide resin prepolymer;

[0066] Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer at a mass ratio of 100:10, and adding tetrahydrophthalic anhydride to obtain a mixed resin;

[0067] Step S4, adding 1 part of benzoic acid, 1 part of 1-methylimidazole, 2 parts of KH-550 and 30 parts of nano-silicon dioxide to the mixed resin in sequence, stirring at 60° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

[0068] Performance Testing

[0069] Table 1 Performance data of Examples 1-5

[0070]

[0071] Specifically, it can be seen from Table 1 that when the addition ratio of the modified bismaleimide resin prepolymer is gradually increased, the toughness and impact resistance of the adhesive are significantly increased.

[0072] In summary, the high-toughness and high-impact composite epoxy adhesive and its preparation method are toughened by pre-polymerization of epoxy resin and polyester polyol, and the second phase structure is toughened by adding modified bismaleimide resin. At the same time, the cross-linking network between the epoxy resin and the modified bismaleimide resin can appropriately reduce the rigidity of the adhesive and improve the impact resistance after curing.

[0073] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a high-toughness and high-impact composite epoxy adhesive, characterized in that: The steps include: Step S1, stirring 10-30 parts of polyester polyol and 100 parts of epoxy resin at 80-120° C. to obtain an epoxy resin prepolymer; Step S2, uniformly mixing 100 parts of bismaleimide resin, 20-30 parts of allyl compound, 10-15 parts of aminophenylacetylene, 30-50 parts of benzoxazine, and 1-5 parts of accelerator, stirring and reacting at 110-130° C. to obtain a modified bismaleimide resin prepolymer; Step S3, mixing the epoxy resin prepolymer and the modified bismaleimide resin prepolymer in a mass ratio of 100:(1-10), and adding an anhydride curing agent to obtain a mixed resin; Step S4, adding 1-5 parts of stabilizer, 1-5 parts of accelerator, 1-5 parts of silane coupling agent and 20-40 parts of filler to the mixed resin in sequence, stirring at 60-80° C., and cooling to obtain a composite epoxy adhesive with high toughness and high impact resistance.

2. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The polyester polyol includes any one or more combinations of polyisophthalic acid-adipate-3-methyl-1,5-pentanediol, polyphthalic acid-adipate-3-methyl-1,5-pentanediol, polyphthalic acid-3-methyl-1,5-pentanediol, polyisophthalic acid-3-methyl-1,5-pentanediol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

3. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The epoxy resin includes at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

4. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The bismaleimide includes any one or more combinations of diphenylmethane bismaleimide, diphenyl ether bismaleimide, meta-phenylene bismaleimide and diphenyl sulfone bismaleimide.

5. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The allyl compound includes any one or more combinations of diallyl bisphenol A, diallyl bisphenol F, diallyl bisphenol S, bisphenol A bisallyl ether, o-diallyl bisphenol A diglycidyl ether and allyl phenol.

6. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The aminophenylacetylene includes any one or more combinations of o-aminophenylacetylene, m-aminophenylacetylene and p-aminophenylacetylene.

7. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The stabilizer includes any one or more combinations of barbituric acid, lactic acid, boric acid, benzoic acid, phenylacetic acid and benzoic acid.

8. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The accelerator includes any one or more combinations of imidazole, imidazole adduct, aromatic amine, aliphatic amine and urea substitute.

9. The high-toughness and high-impact composite epoxy adhesive according to claim 1, characterized in that: The filler comprises any one or more combinations of mica powder, nano silicon dioxide and nano calcium carbonate.

10. A high-toughness and high-impact composite epoxy adhesive obtained by the preparation method according to any one of claims 1 to 9.

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