A surface treatment method for glass microbeads and a silicone adhesive

Abstract

The present invention provides a surface treatment method for glass microspheres, comprising the following steps: A) stirring and dispersing a solvent and a catalyst to obtain a first mixed liquid; B) stirring and dispersing a treatment agent and the first mixed liquid to obtain a second mixed liquid; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate; C) spraying the second mixed liquid onto the glass microspheres, reacting, and obtaining surface-treated glass microspheres. The present invention treats the surface of the glass microspheres with a specific treatment agent, thereby greatly increasing the amount of silanol groups on the glass surface, thereby better combining with the matrix in the silicone adhesive. The present invention can further modify the glass microspheres to keep the density and bonding properties of the adhesive basically unchanged, while increasing the elongation at break by more than 10% and the tensile strength by more than 20%.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a surface treatment method for glass microbeads and a silicone adhesive. Background Art

[0002] Glass beads have the characteristics of low density and high strength, and are widely used in adhesives, coatings, plastic modification, etc. to reduce density and improve thermal insulation properties.

[0003] When glass beads are used in silicone adhesives, they contain silanol groups on their surface, which can react with the crosslinking agent, coupling agent and hydroxy silicone oil in the silicone adhesive to form a certain bonding force. However, due to the limited content of silanol groups on their surface, more crosslinking agent or coupling agent needs to be added during the preparation of the crosslinking agent so that it can form more silicon-oxygen-silicon bonds. However, more crosslinking agent and coupling agent will reduce the elongation at break of the silicone adhesive.

[0004] In order to achieve better microscopic interfacial bonding strength in the process of preparing adhesives, the glass microbeads pre-treated in the prior art need to add more cross-linking agents or coupling agents, which will cause the elongation at break of the silicone adhesive to be lower; if the amount of cross-linking agent and coupling agent added is small, the microscopic interfacial bonding strength between them and the surface of the microbeads is poor, resulting in lower strength of the silicone adhesive.

[0005] Therefore, it is very necessary to provide a glass microbead that improves the strength of the adhesive. Summary of the invention

[0006] In view of this, the present invention provides a glass microbead. The treated glass microbead provided by the present invention can improve the tensile strength and elongation at break of the adhesive while keeping the density and bonding performance of the adhesive basically unchanged.

[0007] The present invention provides a surface treatment method for glass microspheres, characterized in that it comprises the following steps:

[0008] A) stirring and dispersing the solvent and the catalyst to obtain a first mixed solution;

[0009] B) stirring and dispersing the treatment agent and the first mixed solution to obtain a second mixed solution; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate;

[0010] C) spraying the second mixed solution onto the glass microbeads to react and obtain surface-treated glass microbeads.

[0011] Preferably, the solvent is one or more of alcohol, acetone, butanone, ethyl acetate or butyl acetate; and the catalyst is one of dibutyltin dilaurate or dibutyltin dichloride.

[0012] Preferably, the stirring and dispersing in step A) is specifically: dispersing at 1000-1500 r / min for 10-15 min; and the stirring and dispersing in step B) is specifically: dispersing at 1000-1500 r / min for 5-10 min.

[0013] Preferably, the mass ratio of the glass microbeads, the treating agent, the solvent and the catalyst is (30-40): (3-8): (30-50): (0.05-0.1).

[0014] Preferably, in step C), the modification process of the glass microspheres is rotational mixing; the rotation speed is 6-12 r / min; and the mixing temperature is 80-110°C.

[0015] Preferably, in step C), the spraying time is within 60 minutes; and the reaction time is 3 to 5 hours.

[0016] The present invention provides a surface-treated glass microbead, which is prepared by the preparation method described in any one of the above technical solutions.

[0017] The present invention provides a silicone adhesive, comprising the following raw materials in parts by weight:

[0018]

[0019] Preferably, it is characterized in that

[0020] The viscosity of the methyl silicone oil is not higher than 500 cps at 25°C;

[0021] The 107 silicone oil has a viscosity of no more than 20,000 cps at 25°C;

[0022] The calcium carbonate is nano-active calcium carbonate;

[0023] The anti-settling agent is fumed silica;

[0024] The cross-linking agent is a ketoxime type cross-linking agent;

[0025] The silane coupling agent is one or more of r-glycidyloxypropyltrimethoxysilane, r-glycidyloxypropyltriethoxysilane, r-aminopropyltrimethoxysilane and r-aminopropyltriethoxysilane;

[0026] The catalyst is one of dibutyltin dilaurate or dibutyltin dichloride.

[0027] The present invention provides a method for preparing the silicone adhesive according to any one of the above technical solutions, comprising the following steps:

[0028] Methyl silicone oil, 107 silicone oil, a crosslinking agent, and a silane coupling agent are mixed by vacuum stirring, and then calcium carbonate, the surface-treated glass microbeads described in the above technical solution, an anti-settling agent, and a catalyst are added in sequence and stirred to obtain the product.

[0029] Compared with the prior art, the present invention provides a surface treatment method for glass microspheres, comprising the following steps: A) stirring and dispersing a solvent and a catalyst to obtain a first mixed liquid; B) stirring and dispersing a treatment agent and the first mixed liquid to obtain a second mixed liquid; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate; C) spraying the second mixed liquid onto the glass microspheres, reacting, and obtaining surface-treated glass microspheres. The present invention treats the surface of the glass microspheres with a specific treatment agent, thereby greatly increasing the amount of silanol groups on the glass surface, thereby better combining with the matrix in the silicone adhesive. The present invention can further modify the glass microspheres to keep the density and bonding properties of the adhesive basically unchanged, while increasing the elongation at break by more than 10% and the tensile strength by more than 20%. DETAILED DESCRIPTION

[0030] The present invention provides a surface treatment method for glass microspheres and a silicone adhesive. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and they all fall within the scope of protection of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications of this article without departing from the content, spirit and scope of the present invention to achieve and apply the technology of the present invention.

[0031] The present invention provides a surface treatment method for glass microspheres, characterized in that it comprises the following steps:

[0032] A) stirring and dispersing the solvent and the catalyst to obtain a first mixed solution;

[0033] B) stirring and dispersing the treatment agent and the first mixed solution to obtain a second mixed solution; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate;

[0034] C) spraying the second mixed solution onto the glass microbeads to react and obtain surface-treated glass microbeads.

[0035] The surface treatment method of glass microspheres provided by the present invention firstly stirs and disperses a solvent and a catalyst to obtain a first mixed solution.

[0036] According to the present invention, the solvent is one or more of alcohol, acetone, butanone, ethyl acetate or butyl acetate; the catalyst is one of dibutyltin dilaurate or dibutyltin dichloride.

[0037] The stirring dispersion of the present invention specifically includes: dispersing at 1000-1500 r / min for 10-15 min; preferably, dispersing at 1000-1400 r / min for 10-14 min.

[0038] The treating agent and the first mixed solution are stirred and dispersed to obtain a second mixed solution.

[0039] The treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate;

[0040] The stirring dispersion is specifically: dispersing at 1000-1500 r / min for 5-10 min, preferably dispersing at 1000-1400 r / min for 5-9 min.

[0041] The second mixed liquid is sprayed onto the glass microbeads to react and obtain surface-treated glass microbeads.

[0042] The glass microbeads are preferably placed in a rotary mixer at a speed of 6 to 12 r / min and a temperature of 80 to 110°C.

[0043] The second mixed liquid is sprayed onto the glass microbeads within 60 minutes, and then the reaction is continued for 3-5 hours after the spraying is completed to prepare the surface-treated glass microbeads.

[0044] The present invention dilutes the treating agent and then sprays it evenly onto the micro beads. The diluent is a volatile solvent, so that the treating agent and the glass micro beads are evenly and fully contacted, resulting in better effect.

[0045] According to the present invention, the mass ratio of the glass beads, the treatment agent, the solvent and the catalyst is (30-40): (3-8): (30-50): (0.05-0.1); preferably, the mass ratio of the glass beads, the treatment agent, the solvent and the catalyst is (32-38): (4-7): (32-48): (0.06-0.08).

[0046] The present invention can greatly increase the content of silanol on the surface of glass microbeads by treating the glass microbeads with a treating agent, and can achieve good connection with resin, crosslinking agent and coupling agent in silicone adhesive, so that the surface bonding force is greatly improved, and the strength is improved while the elongation at break is improved, thereby achieving the unity of low density, strength and toughness.

[0047] The present invention provides a surface-treated glass microbead, which is prepared by the preparation method described in any one of the above technical solutions.

[0048] The present invention has clearly described the preparation method above, which will not be repeated here.

[0049] The present invention provides a silicone adhesive, comprising the following raw materials in parts by weight:

[0050]

[0051] The silicone adhesive provided by the present invention comprises 10 to 30 parts by weight of methyl silicone oil as raw materials; preferably 10 to 25 parts by weight of methyl silicone oil;

[0052] The methyl silicone oil of the present invention has a viscosity of no more than 500 cps at 25°C.

[0053] The silicone adhesive provided by the present invention comprises raw materials including 20 to 50 parts by weight of 107 silicone oil; preferably including 22 to 48 parts by weight of 107 silicone oil; and more preferably including 25 to 45 parts by weight.

[0054] The 107 silicone oil of the present invention has a viscosity of no more than 20,000 cps at 25°C;

[0055] The silicone adhesive provided by the present invention comprises raw materials including 20 to 30 parts by weight of calcium carbonate; preferably 20 to 28 parts by weight of calcium carbonate; preferably 20 to 26 parts by weight of calcium carbonate;

[0056] The calcium carbonate described in the present invention is nano-active calcium carbonate.

[0057] The silicone adhesive provided by the present invention comprises as raw materials 10 to 20 parts by weight of the surface-treated glass microbeads described in the above technical solution.

[0058] The present invention has already clearly described the surface-treated glass microspheres above, which will not be repeated here.

[0059] The silicone adhesive provided by the present invention comprises raw materials including 0.5 to 1 parts by weight of an anti-settling agent.

[0060] The anti-settling agent is fumed silica.

[0061] The silicone adhesive provided by the present invention comprises 1 to 3 parts by weight of a crosslinking agent as raw materials. The crosslinking agent described in the present invention is a ketoxime crosslinking agent, including but not limited to methyltributylidene oxime silane.

[0062] The silicone adhesive provided by the present invention comprises 0.5 to 1 parts by weight of a silane coupling agent as raw materials. The silane coupling agent of the present invention is preferably one or more of r-glycidyloxypropyltrimethoxysilane, r-glycidyloxypropyltriethoxysilane, r-aminopropyltrimethoxysilane and r-aminopropyltriethoxysilane.

[0063] The silicone adhesive provided by the present invention comprises raw materials including 0.5 to 1 parts by weight of a catalyst, preferably 0.5 to 0.9 parts by weight.

[0064] The catalyst of the present invention is preferably one of dibutyltin dilaurate or dibutyltin dichloride.

[0065] In some preferred embodiments of the present invention, the silicone adhesive comprises the following raw materials in parts by weight:

[0066]

[0067] The present invention provides a method for preparing the silicone adhesive according to any one of the above technical solutions, comprising the following steps:

[0068] Methyl silicone oil, 107 silicone oil, a crosslinking agent, and a silane coupling agent are mixed by vacuum stirring, and then calcium carbonate, the surface-treated glass microbeads described in the above technical solution, an anti-settling agent, and a catalyst are added in sequence and stirred to obtain the product.

[0069] The present invention firstly dehydrates calcium carbonate, surface treated glass micro beads and anti-settling agent; the dehydration specifically comprises: dehydrating at 110-130° C. for 3-6 hours.

[0070] Methyl silicone oil, 107 silicone oil, crosslinking agent and silane coupling agent are placed in a stirring kettle, and mixed for 5-10 minutes at 40-80 r / min under the condition of vacuum degree lower than -0.095 MPa; the stirring kettle is preferably a double planetary stirring kettle.

[0071] Then, calcium carbonate, glass beads and anti-settling agent were added in batches. After each addition, the mixture was stirred for 5 to 10 minutes at a vacuum degree of less than -0.095 MPa and 40 to 80 r / min.

[0072] Finally, add the catalyst, stir for 10 to 15 minutes at 40 to 80 r / min under the condition of vacuum degree lower than -0.095 MPa, and then remove from the kettle.

[0073] The present invention provides a surface treatment method for glass microspheres, comprising the following steps: A) stirring and dispersing a solvent and a catalyst to obtain a first mixed liquid; B) stirring and dispersing a treatment agent and the first mixed liquid to obtain a second mixed liquid; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate; C) spraying the second mixed liquid onto the glass microspheres, reacting, and obtaining surface-treated glass microspheres. The present invention treats the surface of the glass microspheres with a specific treatment agent, thereby greatly increasing the amount of silanol groups on the glass surface, thereby better combining with the matrix in the silicone adhesive. The present invention can further modify the glass microspheres to keep the density and bonding properties of the adhesive basically unchanged, while increasing the elongation at break by more than 10% and the tensile strength by more than 20%.

[0074] In order to further illustrate the present invention, a surface treatment method for glass microspheres and a silicone adhesive provided by the present invention are described in detail below in conjunction with embodiments.

[0075] Example 1

[0076] Glass beads processing method

[0077]

[0078] Treatment method: Use a high-speed disperser to disperse the above solvent and catalyst at 1000r / min for 10 minutes to prepare a mixed solution 1; then disperse the treatment agent and the above mixed solution 1 at 1000r / min for 5 minutes to prepare a mixed solution 2, which is sealed and stored; place the above glass microbeads in a rotating mixer with a speed set to 6r / min and a temperature set to 110°C, spray the mixed solution 2 onto the glass microbeads within 30 minutes, and continue the reaction for 3 hours after spraying to prepare surface-treated glass microbeads.

[0079] Application in adhesives

[0080]

[0081] Preparation method: first, dehydrate calcium carbonate, surface treated glass beads and anti-settling agent at 110°C for 3 hours, place methyl silicone oil, 107 silicone oil, crosslinking agent and silane coupling agent in a double planetary stirred kettle, mix for 5 minutes at a vacuum degree of less than -0.095MPa and 80r / min, then add calcium carbonate, glass beads and anti-settling agent in batches, stir for 10 minutes at a vacuum degree of less than -0.095MPa and 80r / min after each addition, finally add the catalyst, stir for 10 minutes at a vacuum degree of less than -0.095MPa and 80r / min after adding, and remove from the kettle.

[0082] Example 2

[0083] Glass beads processing method

[0084]

[0085] Treatment method: Use a high-speed disperser to disperse the above solvent and catalyst at 1500r / min for 15 minutes to prepare a mixed solution 1; then disperse the treatment agent and the above mixed solution 1 at 1000r / min for 5 minutes to prepare a mixed solution 2, which is sealed and stored; place the above glass microbeads in a rotating mixer with a speed set to 8r / min and a temperature set to 100°C, spray the mixed solution 2 onto the glass microbeads within 50 minutes, and continue the reaction for 4 hours after spraying to prepare surface-treated glass microbeads.

[0086] Application in adhesives

[0087]

[0088] Preparation method: first, dehydrate calcium carbonate, surface treated glass beads and anti-settling agent at 120°C for 4 hours, place methyl silicone oil, 107 silicone oil, crosslinking agent and silane coupling agent in a double planetary stirred kettle, mix for 10 minutes at a vacuum degree of less than -0.095MPa and 60r / min, then add calcium carbonate, glass beads and anti-settling agent in batches, stir for 5 minutes at a vacuum degree of less than -0.095MPa and 80r / min after each addition, finally add the catalyst, stir for 15 minutes at a vacuum degree of less than -0.095MPa and 40r / min after adding, and remove from the kettle.

[0089] Example 3

[0090] Glass beads processing method

[0091]

[0092]

[0093] Treatment method: Use a high-speed disperser to disperse the above solvent and catalyst at 1200r / min for 13 minutes to prepare a mixed solution 1; then disperse the treatment agent and the above mixed solution 1 at 1500r / min for 8 minutes to prepare a mixed solution 2, which is sealed and stored; place the above glass microbeads in a rotating mixer with a speed set to 10r / min and a temperature set to 80°C, spray the mixed solution 2 onto the glass microbeads within 40 minutes, and continue the reaction for 5 hours after spraying to prepare surface-treated glass microbeads.

[0094] Application in adhesives

[0095]

[0096] When preparing the adhesive, first dehydrate the calcium carbonate, surface treated glass beads and anti-settling agent at 120°C for 5 hours, place methyl silicone oil, 107 silicone oil, crosslinking agent and silane coupling agent in a double planetary stirred kettle, mix for 6 minutes at a vacuum degree of less than -0.095MPa and 50r / min, then add calcium carbonate, glass beads and anti-settling agent in batches, stir for 6 minutes at a vacuum degree of less than -0.095MPa and 60r / min after each addition, finally add the catalyst, stir for 12 minutes at a vacuum degree of less than -0.095MPa and 60r / min after adding, and remove from the kettle.

[0097] Comparative Example:

[0098] The preparation methods corresponding to Comparative Examples 1-1, 2-1, and 3-1 are respectively that untreated glass beads are added to Examples 1, 2, and 3, and the preparation methods corresponding to Comparative Examples 1-2, 2-2, and 3-2 are respectively that the glass beads are treated in Examples 1, 2, and 3 by replacing ethyl orthosilicate and methyl orthosilicate with the same weight of vinyltriethoxysilane.

[0099] The density of the products in the embodiments and comparative examples was tested, and the products in the embodiments and comparative examples were coated on a glass plate and cured for 7 days under standard conditions to test their adhesive properties. In addition, a 40 cm*15 cm*2 mm thin sheet was cut into dumbbell sheets and cured for 7 days under standard conditions to test their tensile strength and elongation at break.

[0100] The performance test results are shown in the following table

[0101]

[0102] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A surface treatment method for glass microspheres, characterized in that: The steps include: A) stirring and dispersing a solvent and a catalyst to obtain a first mixed solution; the catalyst is one of dibutyltin dilaurate or dibutyltin dichloride; B) stirring and dispersing the treatment agent and the first mixed solution to obtain a second mixed solution; the treatment agent is one or both of methyl orthosilicate and ethyl orthosilicate; the mass ratio of the glass microspheres, the treatment agent, the solvent and the catalyst is (30-40): (3-8): (30-50): (0.05-0.1); C) spraying the second mixed liquid onto the glass beads within 60 minutes, and continuing the reaction for 3-5 hours after spraying to prepare surface-treated glass beads; the modification process of the glass beads is rotational mixing; the rotation speed is 6-12 r / min; and the rotational mixing temperature is 80-110°C.

2. The method according to claim 1, characterized in that The solvent is one or more of alcohol, acetone, butanone, ethyl acetate or butyl acetate.

3. The method according to claim 1, characterized in that The stirring and dispersing in step A) is specifically: dispersing at 1000-1500 r / min for 10-15 min; the stirring and dispersing in step B) is specifically: dispersing at 1000-1500 r / min for 5-10 min.

4. A surface-treated glass microsphere, characterized in that: The surface treatment method is prepared by any one of claims 1 to 3.

5. A silicone adhesive, characterized in that: The invention comprises the following raw materials in parts by weight:

6. The silicone adhesive according to claim 5, characterized in that: The viscosity of the methyl silicone oil is not higher than 500 cps at 25°C; The 107 silicone oil has a viscosity of no more than 20,000 cps at 25°C; The calcium carbonate is nano-active calcium carbonate; The anti-settling agent is fumed silica; The cross-linking agent is a ketoxime type cross-linking agent; The silane coupling agent is one or more of r-glycidyloxypropyltrimethoxysilane, r-glycidyloxypropyltriethoxysilane, r-aminopropyltrimethoxysilane and r-aminopropyltriethoxysilane; The catalyst is one of dibutyltin dilaurate or dibutyltin dichloride.

7. A method for preparing the silicone adhesive according to any one of claims 5 to 6, characterized in that: The steps include: Methyl silicone oil, 107 silicone oil, a crosslinking agent and a silane coupling agent are mixed in a vacuum stirring manner, and then calcium carbonate, the surface-treated glass microbeads described in claim 4, an anti-settling agent and a catalyst are added in sequence and stirred to obtain the product.

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