Mobile phone narrow frame low-pressure injection molding sealing adhesive and preparation method thereof

Abstract

The invention discloses a mobile phone narrow frame low-pressure injection molding sealing adhesive and a preparation method thereof, and belongs to the technical field of adhesives. According to the technical scheme, the adhesive is characterized by being prepared from, by weight, 35-46 parts of aliphatic epoxy resin, 10-20 parts of polyether polyol, 16-25 parts of reactive diluent, 15-20 parts of toughened resin, 1.4-2.0 parts of initiator, 0.8-1.2 parts of coupling agent and 1.5-2.0 parts of fumed silica, and an adhesive layer obtained after the adhesive is subjected to UV curing is low in shrinkage rate, high in modulus and good in adhesion property. The width of the mobile phone frame can be well controlled, compared with a plastic piece, the screen-to-body ratio of a mobile phone screen can be further improved, and meanwhile the requirements for bonding and reliability of a client side can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and particularly to a low-pressure injection molding sealant adhesive for narrow bezels of mobile phones and a preparation method thereof. Background Art

[0002] The mobile phone bezel is an important part of the mobile phone structure, located between the screen and the body. Its main functions are to provide support for the screen to prevent it from being damaged by external forces, and to help fix internal components such as the battery and motherboard to ensure their stability. In previous generations of mobile phones, the form of the mobile phone bezel was a plastic shell connecting the mobile phone screen and the rear shell. After narrow bezels became the trend of mobile phones, the strength of plastic parts decreased significantly, unable to meet the reliability requirements of mobile phones. Although the mobile phone bezel is crucial in mobile phone design, there are still some problems: (1) The connection between the bezel and the screen or the body is tight, and the repair cost is relatively high after damage; (2) The width of the bezel directly affects the screen-to-body ratio, and an overly wide bezel will reduce the visual experience. Summary of the Invention

[0003] In order to solve the problems in the prior art, the present invention provides a low-pressure injection molding sealant adhesive for narrow bezels of mobile phones and a preparation method thereof. The adhesive layer obtained by UV-curing the adhesive has a low shrinkage rate and a high modulus, can well control the width of the mobile phone bezel, and compared with plastic parts, can further improve the screen-to-body ratio of the mobile phone screen, while meeting the bonding and reliability requirements of the client.

[0004] The first object of the present invention is to provide a low-pressure injection molding sealant adhesive for narrow bezels of mobile phones, and the following technical solution is adopted: A low-pressure injection molding sealant adhesive for narrow bezels of mobile phones, the adhesive comprising the following raw materials in parts by weight: 35-46 parts of aliphatic epoxy resin, 10-20 parts of polyether polyol, 16-25 parts of reactive diluent, 15-20 parts of toughening resin, 1.4-2.0 parts of initiator, 0.8-1.2 parts of coupling agent, and 1.5-2.0 parts of fumed silica.

[0005] By adopting the above technical solution, using aliphatic epoxy resin as the main component of the adhesive can provide good adhesion for the adhesive. Therefore, when it is used in combination with polyether polyol and toughening resin, the flexibility and bonding strength of the adhesive can be significantly improved. The combination of fumed silica and coupling agent further enhances the hardness, wear resistance and weather resistance of the adhesive. In addition, the combined use of the above raw materials in this application can also effectively reduce the shrinkage rate of the adhesive, and because the adhesive obtained in this application has good hardness, the adhesive can adapt to various complex environments and stress conditions.

[0006] In a preferred embodiment, the aliphatic epoxy resin is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate, and the epoxy value is 0.70 - 0.75.

[0007] By adopting the above technical solution, when the aliphatic epoxy resin is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate, its volume shrinkage is small during the UV curing process through ring-opening polymerization reaction. The ring-opening reaction has a lower shrinkage rate compared with the traditional free radical polymerization. Moreover, the cyclohexene structure in 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate has relatively high rigidity, and the molecular rearrangement during curing is small, reducing the volume shrinkage. And due to the ring-opening polymerization and the rigid structure, the volume shrinkage during the curing process is significantly reduced, which is suitable for high-precision applications.

[0008] In a preferred embodiment, the toughening resin is a carboxyl-containing acrylate oligomer.

[0009] By adopting the above technical solution, when the toughening resin is a carboxyl-containing acrylate oligomer added, during the UV curing process, the carboxyl group and the epoxy group react to form an ester bond and a hydroxyl group, thereby optimizing the crosslinking density, making the crosslinking network more uniform, reducing the volume shrinkage. At the same time, the soft segment in the carboxyl-containing acrylate oligomer can also increase the flexibility of the adhesive, and the flexibility of the carboxyl-containing acrylate oligomer can relieve the internal stress during the UV curing process, further reducing the shrinkage rate.

[0010] In a preferred embodiment, the carboxyl-containing acrylate oligomer is obtained by the following preparation method: Under nitrogen protection, butyl acrylate, acrylonitrile and acrylic acid are added to a solvent, and after water bath heating to 85 ± 3 °C, an ethyl acetate solution containing dodecyl mercaptan is added, and a toluene solution containing benzoyl peroxide is added dropwise. After reacting for 5 h, a chain terminator is added, and then after continuing to react for 1 h, vacuum filtration is carried out to obtain the carboxyl-containing acrylate oligomer.

[0011] In a preferred embodiment, the weight ratio of butyl acrylate, acrylonitrile and acrylic acid is 15:(2 - 5):1.

[0012] By adopting the above technical solution, when the carboxyl-containing acrylate oligomer is polymerized from butyl acrylate, acrylonitrile and acrylic acid in a ratio of 15:(2 - 5):1, it can effectively improve the toughness of the adhesive.

[0013] In a preferred embodiment, the reactive diluent is oxetane.

[0014] In a preferred embodiment, the initiator is composed of isopropylphenyl ferrocene hexafluorostibate, diaryliodonium salt, and cumene hydroperoxide in a weight ratio of (0.1 - 0.3):(0.4 - 0.6):(0.9 - 1.1).

[0015] By adopting the above technical solution, the combined use of three initiators can significantly improve the curing efficiency and shorten the curing time. The reason is that isopropylphenyl ferrocene hexafluorostibate and diaryliodonium salt act together to efficiently initiate the ring-opening of aliphatic epoxy resin and react with carboxyl-containing acrylate oligomer to form a network structure with a high crosslinking density. Cumene hydroperoxide initiates the free radical polymerization of carboxyl-containing acrylate oligomer and reactive diluent, and cooperates with the network formed by the ring-opening polymerization of aliphatic epoxy resin to form an interpenetrating network structure, realizing more uniform and thorough curing, which helps to improve the hardness of the adhesive and thus ensures the high modulus of the adhesive.

[0016] In a preferred embodiment, the coupling agent is γ-(2,3-epoxypropane) propyltrimethoxysilane.

[0017] The second aspect of the present invention is to provide a preparation method of the mobile phone narrow bezel low-pressure injection molding sealant as described above. According to the formula amount, aliphatic epoxy resin, polyether polyol, reactive diluent, toughening resin, initiator, coupling agent and fumed silica are stirred and mixed to obtain the adhesive.

[0018] In summary, the present invention has the following beneficial effects: 3,4-epoxycyclohexene methyl-3,4-epoxycyclohexene carboxylate and carboxyl-containing acrylate oligomer can form an interpenetrating network structure with a high crosslinking density under the combined action of three initiators, evenly distribute stress, thereby reducing the shrinkage rate. At the same time, the formed high crosslinking density and rigid structure improve the hardness, heat resistance and chemical resistance of the adhesive, while the combination of polyether polyol and carboxyl-containing acrylate oligomer balances the rigidity of the crosslinking network and improves the flexibility and impact resistance of the adhesive. Specific Embodiments

[0019] The present invention will be further described in detail below with reference to embodiments. All reagents not indicating the manufacturer are conventional reagent products that can be obtained through commercial purchase.

[0020] Preparation Example 1 A preparation method of a carboxyl-containing acrylate oligomer, comprising the following steps: Under nitrogen protection, butyl acrylate, acrylonitrile and acrylic acid are added to ethyl acetate, and after water bath heating to 85±3°C, an ethyl acetate solution containing dodecyl mercaptan is added, and a toluene solution containing benzoyl peroxide is added dropwise. After reacting for 5 h, hydroquinone chain terminator is added, and after reacting for another 1 h, vacuum filtration is carried out to obtain the carboxyl-containing acrylate oligomer; Wherein the weight ratio of butyl acrylate, acrylonitrile and acrylic acid is 15:2:1, and the addition amount of dodecyl mercaptan is 0.1% of the total weight of butyl acrylate, acrylonitrile and acrylic acid.

[0021] Preparation Example 2 A preparation method of a carboxyl-containing acrylate oligomer, comprising the following steps: Under nitrogen protection, add butyl acrylate, acrylonitrile, and acrylic acid to ethyl acetate, heat in a water bath to 85 ± 3 °C, then add an ethyl acetate solution containing dodecyl mercaptan, dropwise add a toluene solution containing benzoyl peroxide, react for 5 h, add a hydroquinone chain terminator, and then continue to react for 1 h, and then perform vacuum filtration to obtain the carboxyl-containing acrylate oligomer; Wherein the weight ratio of butyl acrylate, acrylonitrile, and acrylic acid is 15:4:1, and the addition amount of dodecyl mercaptan is 0.1% of the total weight of butyl acrylate, acrylonitrile, and acrylic acid.

[0022] Preparation Example 3 A preparation method of a carboxyl-containing acrylate oligomer, comprising the following steps: Under nitrogen protection, add butyl acrylate, acrylonitrile, and acrylic acid to ethyl acetate, heat in a water bath to 85 ± 3 °C, then add an ethyl acetate solution containing dodecyl mercaptan, dropwise add a toluene solution containing benzoyl peroxide, react for 5 h, add a hydroquinone chain terminator, and then continue to react for 1 h, and then perform vacuum filtration to obtain the carboxyl-containing acrylate oligomer; Wherein the weight ratio of butyl acrylate, acrylonitrile, and acrylic acid is 15:5:1, and the addition amount of dodecyl mercaptan is 0.1% of the total weight of butyl acrylate, acrylonitrile, and acrylic acid.

[0023] Example 1 A preparation method of a narrow bezel low-pressure injection molding sealing adhesive for mobile phones, comprising the following preparation steps: Stir and mix 3.5 kg of aliphatic epoxy resin, 1 kg of polyether polyol (average molecular weight 2000, Dow VORANOL), 1.6 kg of active diluent, 1.5 kg of toughening resin, 0.14 kg of initiator, 0.08 kg of coupling agent, and 0.15 kg of fumed silica in a high-speed mixer to obtain the adhesive; Wherein the aliphatic epoxy resin is aliphatic epoxy resin ERL-4221, also known as 3,4-epoxycyclohexenylmethyl-3,4-epoxycyclohexene carboxylate, with an epoxy value of 0.70 - 0.75 and a CAS number of 2386-87-0; The toughening resin uses the carboxyl-containing acrylate oligomer obtained in Preparation Example 1; The active diluent uses oxetane; The initiator is composed of isopropylphenyl ferrocene hexafluorophosphate, diaryliodonium salt, and cumene hydroperoxide with a weight ratio of 0.1:0.4:0.9; The coupling agent uses γ-(2,3-epoxypropyl)trimethoxysilane.

[0024] Example 2 A preparation method of a narrow bezel low-pressure injection molding sealant for mobile phones, comprising the following preparation steps: mixing 4.1 kg of aliphatic epoxy resin, 1.5 kg of polyether polyol (average molecular weight 2000, Dow VORANOL), 2.0 kg of active diluent, 1.8 kg of toughening resin, 0.17 kg of initiator, 0.10 kg of coupling agent and 0.18 kg of fumed silica in a high-speed mixer to obtain the sealant; The aliphatic epoxy resin is aliphatic epoxy resin ERL-4221, also known as 3,4-epoxycyclohexene methyl-3,4-epoxycyclohexene carboxylate, with an epoxy value of 0.70-0.75 and a CAS number of 2386-87-0; The toughening resin is the carboxyl group-containing acrylate oligomer obtained in Preparation Example 1; The active diluent is oxetane; The initiator is composed of isopropylphenyl ferrocene hexafluorantimonate, diaryliodonium salt and cumene hydroperoxide with a weight ratio of 0.1:0.4:0.9; The coupling agent is γ-(2,3-epoxypropane) propyltrimethoxysilane.

[0025] Example 3 A preparation method of a narrow bezel low-pressure injection molding sealant for mobile phones, comprising the following preparation steps: mixing 4.6 kg of aliphatic epoxy resin, 2 kg of polyether polyol (average molecular weight 2000, Dow VORANOL), 2.5 kg of active diluent, 2 kg of toughening resin, 0.20 kg of initiator, 0.12 kg of coupling agent and 0.20 kg of fumed silica in a high-speed mixer to obtain the sealant; The aliphatic epoxy resin is aliphatic epoxy resin ERL-4221, also known as 3,4-epoxycyclohexene methyl-3,4-epoxycyclohexene carboxylate, with an epoxy value of 0.70-0.75 and a CAS number of 2386-87-0; The toughening resin is the carboxyl group-containing acrylate oligomer obtained in Preparation Example 1; The active diluent is oxetane; The initiator is composed of isopropylphenyl ferrocene hexafluorantimonate, diaryliodonium salt and cumene hydroperoxide with a weight ratio of 0.1:0.4:0.9; The coupling agent is γ-(2,3-epoxypropane) propyltrimethoxysilane.

[0026] Example 4 A preparation method of a narrow bezel low-pressure injection molding sealant for mobile phones, which is different from Example 2 in that the toughening resin is the carboxyl group-containing acrylate oligomer obtained in Preparation Example 2, and the others are the same as in Example 2.

[0027] Example 5 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, which is different from Example 2 in that the toughening resin uses the carboxyl - containing acrylate oligomer obtained in Preparation Example 3, and the others are the same as in Example 2.

[0028] Example 6 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, which is different from Example 2 in that the weight ratio of cumylferrocenium hexafluoroantimonate, diaryliodonium salt, and cumene hydroperoxide is 0.2:0.5:1.0, and the others are the same as in Example 2.

[0029] Example 7 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, which is different from Example 2 in that the weight ratio of cumylferrocenium hexafluoroantimonate, diaryliodonium salt, and cumene hydroperoxide is 0.3:0.6:1.1, and the others are the same as in Example 2.

[0030] Example 8 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, with the total amount of initiator unchanged. It is different from Example 2 in that the initiator is composed of cumylferrocenium hexafluoroantimonate and cumene hydroperoxide according to a weight ratio of 0.1:0.9, and the others are the same as in Example 2.

[0031] Example 9 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, with the total amount of initiator unchanged. It is different from Example 2 in that the initiator is composed of diaryliodonium salt and cumene hydroperoxide according to a weight ratio of 0.4:0.9, and the others are the same as in Example 2.

[0032] Example 10 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, with the total amount of initiator unchanged. It is different from Example 2 in that the initiator is composed of cumylferrocenium hexafluoroantimonate and diaryliodonium salt according to a weight ratio of 0.1:0.4, and the others are the same as in Example 2.

[0033] Example 11 A preparation method of a narrow - bezel low - pressure injection - molding sealant adhesive for mobile phones, which is different from Example 2 in that an equal amount of bis((3,4 - epoxycyclohexyl)methyl)adipate is used to replace 3,4 - epoxycyclohexenylmethyl - 3,4 - epoxycyclohexene carboxylate, and the others are the same as in Example 2. Bis((3,4 - epoxycyclohexyl)methyl)adipate is Dow Chemical UVR - 6128, with an epoxy equivalent of about 190 - 210 g / eq.

[0034] Comparative Example 1 A preparation method of a narrow - border low - pressure injection - molded sealing adhesive for mobile phones, which is different from Example 2 in that there is no carboxyl - containing acrylate oligomer as a toughening resin in the raw materials, and the others are the same as in Example 2.

[0035] Comparative Example 2 A preparation method of a narrow - border low - pressure injection - molded sealing adhesive for mobile phones, which is different from Example 2 in that there is no polyether polyol in the raw materials, and the others are the same as in Example 2.

[0036] Performance testing The adhesives obtained in the above - mentioned examples and comparative examples were cured by a UV lamp, and then the flexibility, shrinkage rate, modulus and peel strength of the cured adhesive layer were measured. The test results are shown in Table 1.

[0037] The flexibility was tested according to the relevant regulations in GB / T1731 - 2020 "Method for the determination of flexibility of paint films". When testing the flexibility, the thickness of the adhesive layer was 500μm; The modulus was determined by a tensile test according to the relevant regulations in GB / T1040.2 - 2006 to evaluate the rigidity of the adhesive layer; the shrinkage rate was calculated from the volume ratio of the adhesive in the liquid state and the cured state by measuring the density of the two states, and the measurement of the density was carried out according to the relevant regulations in GB / T13354 - 92 and GB / T533 - 2008.

[0038] Table 1 Test results of the adhesive It can be seen from Table 1 that: The adhesives obtained in Examples 1 - 3 of the present application have a flexibility of 3.5mm or less, a modulus of more than 4.2MPa, a shrinkage rate ≤0.4%, and a peel strength ≥37N / 25mm. This shows that the adhesives obtained in Examples 1 - 3 of the present application have good adhesive properties, good flexibility, and a relatively high modulus, indicating that the adhesive has good rigidity and strong anti - deformation ability.

[0039] Compared with Example 2, in Examples 4-5, when the carboxyl group-containing acrylate oligomers are the carboxyl group-containing acrylic oligomers obtained in Preparation Example 2 and Preparation Example 3 respectively, the flexibility, shrinkage rate, and peel strength of the adhesive obtained in Examples 4-5 are lower than those in Example 2, and the modulus increases. The reason is that when the content of acrylonitrile in the carboxyl group-containing acrylate oligomer increases, the number of hard segment chains in the carboxyl group-containing acrylate oligomer increases, making the rigidity of the carboxyl group-containing acrylate oligomer enhanced. As a result, the modulus of the finally obtained adhesive increases, so the force of the adhesive to resist deformation during curing increases, and the shrinkage rate decreases. However, the flexibility and peel strength of the adhesive will decrease accordingly. Therefore, when the addition ratios of butyl acrylate, acrylonitrile, and acrylic acid are controlled within the ranges defined in this application, the flexibility, peel strength, shrinkage rate, and rigidity of the final adhesive can be effectively ensured.

[0040] Compared with Example 2, in Examples 6-7, when the addition ratios of the three initiators change, the properties of the adhesive obtained in Examples 6-7 are basically the same as those of the adhesive obtained in Example 2, indicating that when the addition ratios of the three initiators are within the ranges of this application, the properties of the adhesive can be ensured.

[0041] Compared with Example 2, in Examples 8-10, when only two initiators are used, such as the combination of isopropylphenyl ferrocene hexafluorantimonate and cumene hydroperoxide or the combination of diaryliodonium salt and cumene hydroperoxide or the combination of isopropylphenyl ferrocene hexafluorantimonate and diaryliodonium salt, the flexibility, peel strength, and modulus of the adhesive obtained in Examples 8-10 are significantly reduced, and the shrinkage rate increases significantly. The reason may be that when only two of the initiators are used, the curing of the adhesive is uneven. In some places, there is excessive crosslinking with a high modulus, and in some places, there is insufficient crosslinking with a low modulus, resulting in a decline in the overall performance of the adhesive. This further shows that the combined use of the three initiators effectively ensures the properties of the adhesive.

[0042] Compared with Example 2, in Example 11, when ((3,4-epoxycyclohexyl)methyl)adipate is used instead of 3,4-epoxycyclohexenylmethyl-3,4-epoxycyclohexene carboxylate, the modulus of the adhesive increases significantly, resulting in a decrease in the flexibility and peel strength of the adhesive and a decrease in the shrinkage rate. It can be seen that when the aliphatic epoxy resin uses 3,4-epoxycyclohexenylmethyl-3,4-epoxycyclohexene carboxylate, it can ensure that the adhesive has a relatively high modulus, and at the same time has good peel strength and flexibility.

[0043] Comparing Comparative Example 1 with Example 2, when the carboxyl group-containing acrylate polymer is missing in the raw materials, all the properties of Comparative Example 1 show a significant decrease. The reason is that the lack of the carboxyl group-containing acrylate polymer leads to a decrease in the crosslinking density of the system, resulting in a decrease in the modulus of the adhesive, and the decrease in the modulus may cause a decrease in the initial tack and cohesion of the adhesive, thus affecting the peel strength. Moreover, after the lack of the carboxyl group-containing acrylate polymer, the rigid structure part in the material is missing and the flexible part increases, making the adhesive softer and more flexible.

[0044] Comparing Comparative Example 2 with Example 2, when the polyether polyol (average molecular weight 2000, Dow VORANOL) is missing in the raw materials, the crosslinking density of the adhesive obtained in Comparative Example 2 increases during curing. The reason is that the flexible chain segments of the polyether polyol (average molecular weight 2000, Dow VORANOL) can balance the rigidity and toughness of the adhesive. When the polyether polyol (average molecular weight 2000, Dow VORANOL) is missing, the rigidity of the adhesive significantly increases and the modulus increases greatly. When it needs to withstand dynamic stress or impact, due to the low flexibility, the peel strength also decreases. Thus, it can be seen that the combined use of each raw material in this application effectively guarantees the performance of the adhesive.

[0045] The examples of this specific embodiment are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone, characterized in that: The adhesive comprises the following raw materials in parts by weight: 35-46 parts of aliphatic epoxy resin, 10-20 parts of polyether polyol, 16-25 parts of active diluent, 15-20 parts of toughening resin, 1.4-2.0 parts of initiator, 0.8-1.2 parts of coupling agent and 1.5-2.0 parts of fumed silica.

2. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 1, characterized in that: The aliphatic epoxy resin is 3,4-epoxycyclohexenemethyl-3,4-epoxycyclohexenoate, and the epoxy value is 0.70-0.

75.

3. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 1, characterized in that: The toughening resin is a carboxyl-containing acrylate oligomer.

4. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 3, characterized in that: The carboxyl-containing acrylate oligomer is obtained by the following preparation method: under nitrogen protection, butyl acrylate, acrylonitrile and acrylic acid are added to a solvent, heated to 85±3° C. in a water bath, an ethyl acetate solution containing dodecyl mercaptan is added, a toluene solution containing dibenzoyl peroxide is added dropwise, a segment terminator is added after reacting for 5 hours, the reaction is continued for another hour, and then vacuum filtration is performed to obtain the carboxyl-containing acrylate oligomer.

5. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 4, characterized in that: The weight ratio of butyl acrylate, acrylonitrile and acrylic acid is 15:(2-5):

1.

6. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 1, characterized in that: The active diluent is oxetane.

7. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 1, characterized in that: The initiator is composed of cumyl ferrocenium hexafluoroantimonate, diaryliodonium salt and cumene hydroperoxide in a weight ratio of (0.1-0.3): (0.4-0.6): (0.9-1.1).

8. The low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone according to claim 1, characterized in that: The coupling agent is γ-(2,3-propylene oxide)propyltrimethoxysilane.

9. A method for preparing a low-pressure injection molding sealing adhesive for a narrow frame of a mobile phone as claimed in any one of claims 1 to 8, characterized in that: According to the formula, aliphatic epoxy resin, polyether polyol, active diluent, toughening resin, initiator, coupling agent and fumed silica are stirred and mixed to obtain a bonding adhesive.

Images