Degradable adhesive and preparation method thereof

Abstract

The invention provides a degradable adhesive and a preparation method thereof, and belongs to the field of adhesives. The degradable epoxy resin disclosed by the invention contains four-functionality epoxy groups, so that a high-crosslinking structure can be formed, and the mechanical property and the thermal property of a system are improved. And meanwhile, the contained rigid bicyclic diacetal structure can be degraded in an HCl solution, so that the recovery of a bonded material and the environmental protection are facilitated.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and more specifically to a biodegradable adhesive and its preparation method. Background Technology

[0002] Electronic components may become unusable during manufacturing due to operational errors or machine malfunctions. The dismantling and recycling of these discarded components is a long-standing problem for manufacturers. Electronic components often use thermoplastic adhesives to bond them, so these adhesives need to be softened under high temperatures before dismantling. However, a small amount of residual adhesive may remain after dismantling. Summary of the Invention

[0003] This invention provides a biodegradable adhesive and its preparation method. The biodegradable epoxy resin provided by this invention not only has good mechanical properties, but can also be degraded in HCl solution, which is beneficial to the recycling of electronic components and environmental protection.

[0004] This invention provides a biodegradable adhesive, comprising the following components by mass fraction: Filler 20-40%, biodegradable epoxy resin 5-15%, epoxy resin 40-50%, diluent 6-14%, curing agent 5-10%, curing accelerator 0.5-1%, coupling agent 0-0.5%; The biodegradable epoxy resin has the structural formula shown in Formula I: Formula I.

[0005] Preferably, the filler comprises silicon dioxide and / or aluminum oxide.

[0006] Preferably, the mass ratio of the biodegradable epoxy resin to the epoxy resin is 1:2.5~10.

[0007] Preferably, the epoxy resin includes one or more of bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AD ​​type epoxy resin, bisphenol S type epoxy resin, hydantoin epoxy resin, and phenolic epoxy resin.

[0008] Preferably, the diluent includes one or more of butyl glycidyl ether, polyethylene glycol diglycidyl ether, pentaerythritol glycidyl ether, neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, EPON 828, and EPON 1001.

[0009] Preferably, the curing agent includes one or more of dicyandiamide, cyanamide, diaminodiphenylamine, hexahydrophthalic anhydride, diaminodiphenyl sulfone, isopropyldiamine, and diaminodiphenyl ether.

[0010] Preferably, the curing accelerator comprises one or more of 1-benzyl-2-methylimidazole, 1-propyl-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, PN23J, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2-undecylimidazole-1-ethyl)-S-triazine, and 2,4-diamino-6-(2-undecylimidazole-1-ethyl)-S-triazine and their derivatives.

[0011] Preferably, the coupling agent comprises one or more of γ-aminopropyltrimethylsilane, 3-methacryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, and γ-glycidoxypropyltriethoxysilane.

[0012] This invention also provides a method for preparing the biodegradable adhesive described in the above technical solution, comprising the following steps: The diluent, biodegradable epoxy resin, epoxy resin and coupling agent are first mixed to obtain a first mixture; The first mixture is then mixed and ground with a curing agent, a curing accelerator, and a filler to obtain the biodegradable adhesive.

[0013] The biodegradable epoxy resin of this invention contains tetrafunctional epoxy groups, which can form a highly cross-linked structure, increasing the mechanical and thermal properties of the system. Simultaneously, the rigid bicyclic diacetal structure it contains can degrade in HCl solution, which is beneficial for the recycling of the bonded materials and environmental protection. Detailed Implementation

[0014] This invention provides a biodegradable adhesive, comprising the following components by mass fraction: Filler 20-40%, biodegradable epoxy resin 5-15%, epoxy resin 40-50%, diluent 6-14%, curing agent 5-10%, curing accelerator 0.5-1%, coupling agent 0-0.5%; The biodegradable epoxy resin has the structural formula shown in Formula I: Formula I.

[0015] The biodegradable adhesive of the present invention comprises 20-40% filler by mass fraction, which may be 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, or 39% in specific embodiments of the present invention; the filler preferably comprises silica.

[0016] In this invention, the mass ratio of the biodegradable epoxy resin to the epoxy resin is preferably 1:2.5 to 10, and in specific embodiments of this invention, it can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9.

[0017] The components of the biodegradable adhesive of the present invention, by mass fraction, include 5-15% biodegradable epoxy resin, which may be 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13% or 14% in specific embodiments of the present invention; By mass fraction, the components of the biodegradable adhesive of the present invention include 40-50% epoxy resin, which in specific embodiments of the present invention may be 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, or 49%; the epoxy resin preferably includes one or more of bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AD ​​type epoxy resin, bisphenol S type epoxy resin, hydantoin epoxy resin, and phenolic epoxy resin.

[0018] The components of the biodegradable adhesive of the present invention, by mass fraction, include 6-14% diluent, which in specific embodiments of the present invention may be 7%, 8%, 9%, 10%, 11%, 12% or 13%; the diluent preferably includes one or more of butyl glycidyl ether, polyethylene glycol diglycidyl ether, pentaerythritol glycidyl ether, neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, EPON 828 and EPON 1001.

[0019] The components of the biodegradable adhesive of the present invention, by mass fraction, include 5-10% curing agent, which may be 6%, 7%, 8% or 9% in specific embodiments of the present invention; the curing agent preferably includes one or more of dicyandiamide, cyanamide, diaminodiphenylamine, hexahydrophthalic anhydride, diaminodiphenyl sulfone, isopropyldiamine and diaminodiphenyl ether.

[0020] The components of the biodegradable adhesive of the present invention, by mass fraction, include 0.5-1% of a curing accelerator, which may be 0.6%, 0.7%, 0.8%, or 0.9% in specific embodiments of the present invention; the curing accelerator preferably includes one or more of 1-benzyl-2-methylimidazole, 1-propyl-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, PN23J, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2-undecylimidazole-1-ethyl)-S-triazine and 2,4-diamino-6-(2-undecylimidazole-1-ethyl)-S-triazine and their derivatives.

[0021] The biodegradable adhesive of the present invention comprises a coupling agent by mass fraction: 0-0.5%, which may be 0.1%, 0.2%, 0.3% or 0.4% in specific embodiments of the present invention; the coupling agent preferably includes one or more of γ-aminopropyltrimethylsilane, 3-methacryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane and γ-glycidoxypropyltriethoxysilane.

[0022] This invention also provides a method for preparing the biodegradable adhesive described in the above technical solution, comprising the following steps: The diluent, biodegradable epoxy resin, epoxy resin and coupling agent are first mixed to obtain a first mixture; The first mixture is then mixed and ground with a curing agent, a curing accelerator, and a filler to obtain the biodegradable adhesive.

[0023] The following detailed description of the biodegradable adhesive and its preparation method provided by the present invention, with reference to specific embodiments, should not be construed as limiting the scope of protection of the present invention.

[0024] The preparation methods in the examples and comparative examples are as follows: The diluent, biodegradable epoxy resin (i.e., DGEVP), epoxy resin and coupling agent are first mixed to obtain a first mixture; The first mixture is then mixed and ground with a curing agent, a curing accelerator, and a filler to obtain the biodegradable adhesive.

[0025] Example 1 A conductive adhesive based on modified epoxy resin comprises the following components in weight percentage: 30% silica filler DGEVP 9% 40% Bisphenol A type epoxy resin Pentaerythritol glycidyl ether 4% 6% polyethylene glycol diglycidyl ether 5% diaminodiphenylamine Dicyandiamide 5% 1-Propyl-methylimidazolium 1% The product viscosity was tested to be 13680 cps. The glass transition temperature is 120℃. For Lap shear strength tests were performed on aluminum sheets. The bond strength was 25 MPa at 25°C and 8 MPa at 200°C. The sheets can be hydrolyzed in 0.1M HCl solution at room temperature for 3 hours.

[0026] Example 2 A conductive adhesive based on modified epoxy resin comprises the following components in weight percentage: 30% silica filler DGEVP 15% 40% phenolic epoxy resin Neopentyl glycol diglycidyl ether 4% 2% C12-14 alkyl glycidyl ether 8% diaminodiphenyl sulfone PN23J 0.8% Vinyltris(β-methoxyethoxy)silane 0.2%.

[0027] The product viscosity was tested to be 16400 cps. The glass transition temperature is 136℃. For Lap shear strength tests were conducted on aluminum sheets, showing a bond strength of 29 MPa at 25°C and 12 MPa at 200°C. The sheets can be hydrolyzed in 0.1M HCl solution at room temperature for 3 hours.

[0028] Example 3 A conductive adhesive based on modified epoxy resin comprises the following components in weight percentage: 30% silica filler DGEVP 5% 50% hydrogenated bisphenol A type epoxy resin EPON 1001 8% 6% hexahydrophthalic anhydride 1-Cyanoethyl-2-methylimidazolium 0.5% 0.5% γ-glycidyl oxypropyltrimethoxysilane.

[0029] The product viscosity was tested to be 10600 cps. The glass transition temperature is 127℃. For Lap shear strength tests were performed on aluminum sheets. The bond strength was 25 MPa at 25°C and 8 MPa at 200°C. The sheets can be hydrolyzed in 0.1M HCl solution at room temperature for 3 hours.

[0030] Example 4 A conductive adhesive based on modified epoxy resin comprises the following components in weight percentage: 20% silica filler DGEVP 15% Bisphenol S-type epoxy resin 40% Butyl glycidyl ether 14% 10% cyanamide 2,4-Diamino-6-(2-Undecylimidazol-1-ethyl)-S-triazine 0.4% 1-Cyanoethyl-2-ethyl-4-methylimidazolium 0.4% 3-Methacryloxypropyltriethoxysilane 0.2% The product viscosity was tested to be 16640 cps. The glass transition temperature is 139℃. For Lap shear strength tests were conducted on aluminum sheets, showing a bond strength of 33 MPa at 25°C and 14 MPa at 200°C. The sheets can be hydrolyzed in 0.1M HCl solution at room temperature for 3 hours.

[0031] Example 5 A conductive adhesive based on modified epoxy resin comprises the following components in weight percentage: 40% silica filler DGEVP 6% 40% hydrogenated bisphenol A type epoxy resin Neopentyl glycol diglycidyl ether 4% 9% diaminodiphenyl ether 1-Cyanoethyl-2-ethyl-4-methylimidazolium 0.5% 0.5% γ-glycidyl oxypropyltrimethoxysilane.

[0032] The product viscosity was tested to be 11880 cps. The glass transition temperature is 129℃. For Lap shear strength tests were performed on aluminum sheets. The bond strength was 25 MPa at 25°C and 9 MPa at 200°C. The sheets can be hydrolyzed in 0.1M HCl solution at room temperature for 3 hours.

[0033] Comparative Example 1 An epoxy conductive adhesive comprises the following components in weight percentage: 30% silica filler 50% Bisphenol A type epoxy resin 9% polyethylene glycol diglycidyl ether 10% diaminodiphenylmethane 2,4-Diamino-6-(2-Undecylimidazol-1-ethyl)-S-triazine 0.4% 2-Phenylacetyl-4-methyl-5-hydroxymethylimidazolium 0.4% γ-aminopropyltrimethylsilane 0.2% The product viscosity was tested to be 9840 cps. The glass transition temperature is 105℃. For Lap shear strength tests were performed on the aluminum sheets. The bond strength was 18 MPa at 25°C and 5 MPa at 200°C. The aluminum sheets did not hydrolyze in a 0.1M HCl solution at room temperature.

[0034] DGEVP is a bio-based tetrafunctional epoxy resin. With increasing addition, the system exhibits increased adhesion at room temperature, improved temperature resistance, and enhanced adhesion at high temperatures. It can also be hydrolyzed in 0.1M HCl solution, but the system viscosity increases. Comparative examples and those with very low DGEVP content have lower viscosity, lower adhesion at both room and high temperatures, and cannot be hydrolyzed in 0.1M HCl solution at room temperature. Examples with excessively high DGEVP content have high viscosity and poor workability.

[0035] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A biodegradable adhesive, characterized in that, By mass fraction, it includes the following components: Filler 20-40%, biodegradable epoxy resin 5-15%, epoxy resin 40-50%, diluent 6-14%, curing agent 5-10%, curing accelerator 0.5-1%, coupling agent 0-0.5%; The biodegradable epoxy resin has the structural formula shown in Formula I: Formula I.

2. The biodegradable adhesive according to claim 1, characterized in that, The filler includes silicon dioxide and / or aluminum oxide.

3. The biodegradable adhesive according to claim 1, characterized in that, The mass ratio of the biodegradable epoxy resin to the epoxy resin is 1:2.5~10.

4. The biodegradable adhesive according to claim 1, characterized in that, The epoxy resin includes one or more of the following: bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AD ​​type epoxy resin, bisphenol S type epoxy resin, hydantoin epoxy resin, and phenolic epoxy resin.

5. The biodegradable adhesive according to claim 1, characterized in that, The diluent includes one or more of butyl glycidyl ether, polyethylene glycol diglycidyl ether, pentaerythritol glycidyl ether, neopentyl glycol diglycidyl ether, C12-14 alkyl glycidyl ether, EPON 828, and EPON 1001.

6. The biodegradable adhesive according to claim 1, characterized in that, The curing agent includes one or more of dicyandiamide, cyanamide, diaminodiphenylamine, hexahydrophthalic anhydride, diaminodiphenyl sulfone, isopropyldiamine, and diaminodiphenyl ether.

7. The biodegradable adhesive according to claim 1, characterized in that, The curing accelerator includes one or more of 1-benzyl-2-methylimidazolium, 1-propyl-methylimidazolium, 1-cyanoethyl-2-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, PN23J, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 2,4-diamino-6-(2-undecylimidazol-1-ethyl)-S-triazine and 2,4-diamino-6-(2-undecylimidazol-1-ethyl)-S-triazine and their derivatives.

8. The biodegradable adhesive according to claim 1, characterized in that, The coupling agent includes one or more of γ-aminopropyltrimethylsilane, 3-methacryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, and γ-glycidoxypropyltriethoxysilane.

9. A method for preparing the biodegradable adhesive according to any one of claims 1 to 8, characterized in that, Includes the following steps: The diluent, biodegradable epoxy resin, epoxy resin and coupling agent are first mixed to obtain a first mixture; The first mixture is then mixed and ground with a curing agent, a curing accelerator, and a filler to obtain the biodegradable adhesive.

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