Epoxy resin-based adhesive for ceramic cultural relic restoration, preparation method and application

Abstract

The invention discloses an epoxy resin adhesive for ceramic cultural relic restoration, a preparation method and an application thereof, and belongs to the technical field of cultural relic protection and restoration. The specific technical scheme is as follows: the adhesive is composed of two components A and B, wherein the component A comprises the following components in parts by weight: 52-68 parts of epoxy resin, 2-8 parts of diluent, 0.35-1 part of defoamer, and 3.5-15 parts of toughening agent; and the component B comprises the following components in parts by weight: 18-25 parts of amine curing agent and 0-5 parts of curing accelerator. The preparation method comprises the following steps: separately preparing the components A and B, uniformly mixing them, and vacuum degassing to obtain the epoxy resin adhesive. The prepared adhesive has the characteristics of high transparency, excellent weather resistance and high bonding strength. The epoxy resin adhesive prepared by the invention can be cured at room temperature, has high transparency, and has excellent bonding and repairing effect, greatly improving the weather resistance of the adhesive, and significantly extending its yellowing resistance time.

Description

Technical Field

[0001] The present invention belongs to the technical field of cultural relic restoration, and in particular relates to an epoxy resin-based adhesive for ceramic cultural relic restoration, a preparation method and an application thereof. Background Art

[0002] Ancient Chinese ceramics are a dazzling gem in the treasure trove of human history, culture, and art, possessing not only artistic value but also immense historical research value. However, porcelain is brittle, and most porcelain artifacts suffer from damage and loss. This not only diminishes the artifact's artistic beauty but also significantly impacts its historical research value. Therefore, restoration is essential.

[0003] The restoration of porcelain cultural relics generally includes steps such as removing impurities, bonding and reinforcement, filling in defects, and coloring imitation glaze. Among them, bonding and reinforcement is the use of adhesives to repair damaged parts of porcelain cultural relics. Epoxy resin adhesives are widely used in the bonding and reinforcement of cultural relics due to their excellent properties such as good processability, high bonding strength, and water and oil resistance. However, epoxy resins are prone to discoloration after being exposed to ultraviolet rays. This is mainly because the structure of bisphenol A is easily oxidized to produce carbonyl groups, resulting in yellowing, and the free amines produced by the curing agent directly polymerize with the epoxy group, which not only aggravates the temperature rise in the local area of ​​the adhesive and accelerates yellowing, but also leads to incomplete reaction polymerization, difficulty in releasing internal stress, and damage to the mechanical properties of the adhesive. The yellowing problem of epoxy resin not only affects the appearance of the cultural relics, but also deteriorates the mechanical properties of the adhesive, which does not meet the requirements of cultural relic restoration.

[0004] Regarding research on improving the weather resistance of epoxy resins, patent CN201811348480.5 proposes a method for bonding and protecting porcelain artifacts. The adhesive comprises porcelain powder, bisphenol A epoxy resin, nano-titanium dioxide, nano-calcium carbonate, beeswax, rosin, bentonite, ethylene glycol monobutyl ether, zinc oxide, and castor oil triglycidyl ether in a certain proportion as component A; and a modified amine curing agent, surface-modified talc, xanthan gum, DMP-30, 2,6-di-tert-butyl-p-cresol, and 2-hydroxy-2-methylphenylpropane-1-one in a certain proportion as component B. Although this patent improves bond strength and UV resistance, the adhesive has a large number of ingredients, a complex preparation process, and requires heating to cure, which can cause damage to artifacts.

[0005] Patent CN201910594211.5 proposes a highly transparent, UV-resistant epoxy resin adhesive and its preparation method. The adhesive preferably uses liquid hydrogenated bisphenol A epoxy resin or solid hydrogenated bisphenol A epoxy resin as the main resin, along with a silicone-modified epoxy resin. The adhesive significantly improves its weather resistance by adding a UV absorber. This method requires hydrogenation of the main epoxy resin and the addition of a UV absorber, which increases the preparation cost. Summary of the Invention

[0006] In order to solve the technical problems in the prior art that epoxy resins are prone to yellowing, affecting the appearance of cultural relics and deteriorating mechanical properties, the present invention discloses an epoxy resin-based adhesive for ceramic cultural relic restoration, preferably containing a low-viscosity hydroxyl-terminated base polyether additive, which improves the toughness of bisphenol A epoxy resin while improving its weather resistance, and significantly increases the yellowing resistance time of the product.

[0007] The present invention also discloses a method for preparing an epoxy resin-based adhesive for ceramic cultural relic restoration. On the basis of meeting the basic requirements for cultural relic protection, the adhesive is prepared by optimizing materials and proportions, and the preparation method is simple.

[0008] The present invention also discloses the application of epoxy resin-based adhesive for ceramic cultural relic restoration. On the premise of maintaining mechanical properties that meet the requirements of cultural relic protection, the weather resistance is improved and the yellowing resistance time is greatly extended.

[0009] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an epoxy resin-based adhesive for ceramic cultural relic restoration, comprising component A and component B:

[0010] Component A includes the following components in parts by weight: 52-68 parts of epoxy resin, 2-8 parts of diluent, 0.35-1 part of defoaming agent, and 3.5-15 parts of toughening agent;

[0011] The epoxy resin is composed of bisphenol A epoxy resin and chemically modified liquid epoxy resin. The bisphenol A epoxy resin accounts for 70-80 parts of the epoxy resin component, and the chemically modified liquid epoxy resin accounts for 20-30 parts of the epoxy resin component.

[0012] Component B includes the following components in parts by weight: 18 to 25 parts of an amine curing agent and 0 to 5 parts of a curing accelerator.

[0013] The bisphenol A epoxy resin is one or a combination of any two of DER-330, E-51, and EP4100 with an epoxy equivalent of 170 to 250; the chemically modified liquid epoxy resin is a silicone-modified epoxy resin.

[0014] The defoaming agent is one or a combination of any two or more of Surfynol 104E mainly composed of decanediol, BYK-022 mainly composed of polysiloxane and hydrophobic particles, and Foamex 830 mainly composed of an organic polymer containing fumed silica.

[0015] The diluent in component A of the epoxy resin adhesive for cultural relics restoration is one or a combination of any two or more of butyl glycidyl ether, trimethylolpropane triglycidyl ether, ethylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0016] The toughening agent in component A of the epoxy resin adhesive for cultural relics restoration is a low-viscosity hydroxyl-terminated base-based polyether compound.

[0017] The amine curing agent in component B of the epoxy resin adhesive for cultural relics restoration is a combination of one or more of the alicyclic amine curing agents isophoronediamine (IPDA), polyetheramine D-230, and polyetheramine D-400.

[0018] The curing accelerator in component B of the epoxy resin adhesive for cultural relics restoration is one or a combination of any two or more of benzyldimethylamine, triethylamine, triethanolamine, dimethylethanolamine, and pyridine.

[0019] The adhesive has the characteristics of high transparency and yellowing resistance, tensile shear strength ≥5Mpa, impact strength ≥50KJ / m 2 , light transmittance ≥90%; in the UV aging test box, at 0.68W / m 2 , irradiated at 50℃, yellowing resistance time ≥150h.

[0020] The method for preparing an epoxy resin-based adhesive for ceramic cultural relic restoration comprises the following specific steps:

[0021] 1. Add bisphenol A epoxy resin and chemically modified liquid epoxy resin to the reactor in proportion, heat the reactor to 90-110°C and stir for 2-3 hours to fully mix the epoxy resin, then cool to 60°C, add diluent, defoamer and toughening agent to the reactor in proportion, stir for 1.5 hours, take out and vacuum degas at room temperature to obtain component A;

[0022] 2. Add the amine curing agent and curing accelerator into the reaction kettle in proportion, stir at 40-60°C for 1-2 hours to obtain component B;

[0023] 3. Mix components A and B evenly, and vacuum degas for 5 to 10 minutes to obtain a highly transparent, yellowing-resistant epoxy resin adhesive for cultural relics restoration.

[0024] The application of epoxy resin-based adhesive for ceramic cultural relics restoration is as follows:

[0025] 1. Thoroughly clean the bonding surface of the ceramic artifact, evenly apply epoxy resin adhesive on the bonding surface of the ceramic artifact, fully contact the porcelain fragments to be bonded with the ceramic artifact, and allow excess adhesive to overflow;

[0026] 2. Remove excess adhesive from the surface of the cultural relic and place the ceramic cultural relic in room temperature air to dry for 10 to 24 hours to solidify, thus completing the bonding and repair of the ceramic cultural relic.

[0027] Compared with the existing technology, the specific beneficial effects are embodied in:

[0028] First, the present invention optimizes raw materials, selecting bisphenol A epoxy resin with an epoxy equivalent weight of 170-250 as the primary matrix and mixing it with a small amount of silane-modified epoxy resin. This reduces the cost of cultural relic restoration and improves the adhesive's anti-yellowing properties. The curing agent utilizes alicyclic amines and polyetheramines, which are room-temperature curing agents suitable for cultural relic restoration. The curing process requires no heating and does not damage the artifacts. The raw material ratio is optimized based on the reactivity of the epoxy resin and curing agent to ensure a full curing reaction, reduce the generation of free amines, and significantly enhance the epoxy resin's anti-yellowing properties.

[0029] Second, the present invention optimizes the formula and selects a low-viscosity hydroxyl-terminated linear polyether compound as a toughening agent. Since the polyether compound itself contains a large amount of linear ether bond structures, when it is introduced into the epoxy resin matrix material, it can increase the content of the flexible segment in the material, thereby achieving a toughening effect and ensuring the excellent mechanical properties of the adhesive. In addition, the active end groups of the low-viscosity polyether can participate in the epoxy resin curing reaction, forming a stable cross-linked structure, reducing the curing exotherm peak, making the epoxy resin curing reaction stable, avoiding yellowing caused by local severe temperature rise, and helping to improve the anti-yellowing properties of the epoxy resin. At the same time, the linear polyether compound greatly increases the ether network ratio in the cross-linked network structure of the epoxy resin cured product. The ether bond has strong polarity and can form hydrogen bonds with the phenolic hydroxyl groups in the bisphenol A structure, improving the stability of the epoxy resin, and then reducing the yellowing caused by the carbonylation of the phenolic hydroxyl groups, improving the yellowing resistance of the resin.

[0030] 3. The adhesive formula provided by the present invention has a light transmittance of more than 93%, which is a high light transmittance material with excellent strength. 2 , and yellowing only begins after 150 hours in a 50°C UV accelerated weathering test chamber. Compared with the commonly used adhesives for cultural relics protection, its yellowing resistance time is greatly extended, which can fully meet the requirements of cultural relics protection for filling and bonding materials.

[0031] 4. The adhesive formula provided by the present invention is composed only of an epoxy resin matrix, a curing agent, a defoaming agent and a polyether additive. It has a simple formula, is easy to operate and has good product performance. Implementation Method

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example

[0033] An epoxy resin-based adhesive for ceramic cultural relic restoration consists of components A and B. Component A includes epoxy resins E-51, DER-330, silicone-modified epoxy resins, defoamer BYK-022, diluent n-butyl glycidyl ether, and a low-viscosity hydroxyl-terminated base-based polyether compound as a toughening agent. Component B includes an amine curing agent, isophorone diamine, and a curing accelerator, triethanolamine.

[0034] The preparation method is as follows:

[0035] 1. Preparation of Component A: 43.5 parts of epoxy resin E-51, 10.1 parts of DER-330, and 13.4 parts of organosilicon-modified epoxy resin were added to a reaction kettle in sequence. The temperature of the reaction kettle was raised to 100°C and stirred for 3 hours to allow the epoxy resin to be fully mixed. The temperature was then lowered to 60°C. 1 part of defoamer BYK-022 and 5 parts of diluent n-butyl glycidyl ether were added in sequence. The mixture was stirred for 1.5 hours and then vacuum degassed to obtain Component A.

[0036] 2. Preparation of Component B: Add 25 parts of amine curing agent IPDA and 2 parts of curing accelerator triethanolamine into the reaction kettle at once, heat the reaction kettle to 40°C and stir for 1 hour to mix evenly to obtain component B;

[0037] All parts are by weight.

[0038] 3. In the subsequent work, mix components A and B, stir them thoroughly, and then perform vacuum degassing at room temperature for 10 minutes to obtain the required adhesive.

[0039] The application of epoxy resin-based adhesive for ceramic cultural relics restoration is as follows:

[0040] 1. Thoroughly clean the bonding surface of the ceramic artifact, evenly apply epoxy resin adhesive on the bonding surface of the ceramic artifact, fully contact the porcelain fragments to be bonded with the ceramic artifact, and allow excess adhesive to overflow;

[0041] 2. Remove excess adhesive from the surface of the cultural relic and place the ceramic cultural relic in room temperature air to dry for 10 to 24 hours to solidify, thus completing the bonding and repair of the ceramic cultural relic.

[0042] The gel time and curing time of the adhesive prepared in Example 1 are shown in Table 1.

[0043] The test results of the adhesive gel properties prepared in Example 1 are shown in Table 2. Example

[0044] An epoxy resin-based adhesive for ceramic cultural relic restoration, comprising component A and component B, wherein:

[0045] Component A: 40.3 parts of epoxy resin E-51, 9.3 parts of DER-330, 12.4 parts of silicone-modified epoxy resin, 5 parts of diluent n-butyl glycidyl ether, 1 part of defoamer BYK-022, and 5 parts of toughening agent;

[0046] Component B: 25 parts of amine curing agent IPDA, 2 parts of curing accelerator triethanolamine;

[0047] All parts are by weight.

[0048] The preparation method and application of this embodiment are the same as those of Example 1.

[0049] The gel time and curing time of the adhesive prepared in Example 2 are shown in Table 1.

[0050] The test results of the adhesive gel properties prepared in Example 2 are shown in Table 2. Example

[0051] An epoxy resin-based adhesive for ceramic cultural relic restoration, comprising component A and component B, wherein:

[0052] Component A: 37.7 parts of epoxy resin E-51, 8.7 parts of DER-330, 11.6 parts of silicone-modified epoxy resin, 5 parts of diluent n-butyl glycidyl ether, 1 part of defoamer BYK-022, and 9 parts of toughening agent;

[0053] Component B: 25 parts of amine curing agent IPDA, 2 parts of curing accelerator triethanolamine;

[0054] All parts are by weight.

[0055] The preparation method and application of this embodiment are the same as those of Example 1.

[0056] The gel time and curing time of the adhesive prepared in Example 3 are shown in Table 1.

[0057] The test results of the adhesive gel properties prepared in Example 3 are shown in Table 2. Example

[0058] An epoxy resin-based adhesive for ceramic cultural relic restoration, comprising component A and component B, wherein:

[0059] Component A: 35.1 parts of epoxy resin E-51, 8.1 parts of DER-330, 10.8 parts of silicone-modified epoxy resin, 5 parts of diluent n-butyl glycidyl ether, 1 part of defoamer BYK-022, and 13 parts of toughening agent;

[0060] Component B: 25 parts of amine curing agent IPDA, 2 parts of curing accelerator triethanolamine;

[0061] All parts are by weight.

[0062] The preparation method and application of this embodiment are the same as those of Example 1.

[0063] The gel time and curing time of the adhesive prepared in Example 4 are shown in Table 1.

[0064] The test results of the adhesive gel properties prepared in Example 4 are shown in Table 2.

[0065] Table 1

[0066]

[0067] In order to verify the excellent performance of the adhesive of the present invention, adhesives commonly used in cultural relics restoration were selected for performance comparison, and the results are as follows:

[0068] Table 2

[0069]

[0070] According to the performance test results in Table 2, the adhesives prepared in Examples 1 to 4, firstly, have hardness, adhesion, tensile shear strength, and transmittance that meet the requirements for use and are suitable for adhesive repair of porcelain; secondly, at 0.68 W / m 2 Yellowing only occurs after more than 150 hours in a UV accelerated weathering test chamber at 50°C, a significant improvement compared to commonly used adhesives on the market today. In Example 1, no linear polyether toughening agent was added. Compared to a commercial reagent (Araldite 2020), yellowing resistance was improved. This improvement demonstrates that the present invention can improve yellowing resistance to a certain extent through the optimization of the epoxy resin matrix and curing agent ratio. In Examples 2-4, linear polyether toughening agents were added. Compared to Example 1, tensile shear strength and impact strength were improved, and the UV yellowing resistance was also prolonged, demonstrating that the linear polyether compounds used in the present invention can improve the yellowing resistance of epoxy resins. This demonstrates that the adhesives of the present invention exhibit superior yellowing resistance compared to prior art epoxy resin adhesives.

[0071] It should be noted that the present invention achieves the above effect without adding antioxidants, UV absorbers, and UV screeners. After adding certain antioxidants, UV absorbers, UV screeners and other compounds, its yellowing resistance should be improved to a certain extent again.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. An epoxy resin-based adhesive for ceramic cultural relic restoration, characterized in that: It is composed of component A and component B: The component A comprises the following components in parts by weight: 52-68 parts of epoxy resin, 2-8 parts of diluent, 0.35-1 part of defoaming agent, and 3.5-15 parts of toughening agent; The epoxy resin is composed of bisphenol A epoxy resin and chemically modified liquid epoxy resin, wherein the bisphenol A epoxy resin accounts for 70% to 80% of the epoxy resin component, the epoxy equivalent of the bisphenol A epoxy resin is 170 to 250, and the chemically modified liquid epoxy resin is a silicone-modified epoxy resin, and the chemically modified liquid epoxy resin accounts for 20% to 30% of the epoxy resin component; The toughening agent is a hydroxyl-terminated base-based polyether compound; The B component includes the following components in parts by weight: 18-25 parts of an amine curing agent and 0-5 parts of a curing accelerator; The amine curing agent is one or a combination of any of the following cycloaliphatic amine curing agents: isophorone diamine, polyetheramine D-230, polyetheramine D-400; The curing accelerator is one of benzyldimethylamine, triethylamine, triethanolamine, dimethylethanolamine, and pyridine, or a combination of any multiple thereof.

2. The epoxy resin-based adhesive for ceramic cultural relic restoration according to claim 1, characterized in that: The defoaming agent is one or a combination of any two or more of Surfynol 104E containing tetramethyldecynediol, BYK-022 containing polysiloxane and hydrophobic particles, and Foamex 830 containing an organic polymer containing fumed silica.

3. The epoxy resin-based adhesive for ceramic cultural relic restoration according to claim 2, characterized in that: The diluent is one of butyl glycidyl ether, trimethylolpropane triglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, or a combination of any multiple thereof.

4. The epoxy resin-based adhesive for ceramic cultural relic restoration according to claim 3, characterized in that: The adhesive has the characteristics of high transparency and yellowing resistance, tensile shear strength ≥5Mpa, impact strength ≥50KJ / m 2 , light transmittance ≥90%; in the UV aging test box, at 0.68W / m 2 , irradiated at 50℃, yellowing resistance time ≥150h.

5. A method for preparing the epoxy resin-based adhesive for ceramic cultural relic restoration according to claim 1, characterized in that: The specific preparation steps are as follows:

1. Add bisphenol A epoxy resin and chemically modified liquid epoxy resin to the reactor in proportion, heat the reactor to 90-110°C, stir for 2-3 hours to mix the epoxy resin thoroughly, then cool to 60°C, add diluent, defoamer, and toughening agent to the reactor in proportion, stir for 1.5 hours, take out, and vacuum degas at room temperature to obtain component A; 2. Add the amine curing agent and curing accelerator into the reaction kettle in proportion, stir at 40-60°C for 1-2 hours to obtain component B; 3. Mix components A and B evenly, and perform vacuum degassing for 5 to 10 minutes to obtain epoxy resin adhesive.

6. The use of the epoxy resin-based adhesive for ceramic cultural relic restoration according to claim 1, characterized in that: The specific application steps are as follows:

1. Thoroughly clean the bonding surface of the ceramic artifact, evenly apply epoxy resin adhesive on the bonding surface of the ceramic artifact, fully contact the porcelain fragments to be bonded with the ceramic artifact, and allow excess adhesive to overflow; 2. Remove excess adhesive from the surface of the cultural relic, place the ceramic cultural relic in room temperature air to dry for 10 to 24 hours and then solidify, thus completing the bonding and repair of the ceramic cultural relic.

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