Dealcoholized silicone sealant and method for preparing the same

Abstract

The application belongs to the technical field of sealant and discloses a dealcoholized silicone sealant and a preparation method thereof, the dealcoholized silicone sealant comprises the following components in parts by weight: polyalkoxy terminated 107 glue 100, dimethyl silicone oil 10-50, reinforcing filler 150-300, crosslinking agent 0.5-1, coupling agent 0.2-0.8 and catalyst 3-6; wherein the polyalkoxy terminated 107 glue is obtained by the following steps: firstly, amino silane end termination modification reaction of 107 glue by amino silane to obtain amino silane end termination modified 107 glue; and secondly, polyalkoxy end termination reaction of the amino silane end termination modified 107 glue by epoxy silane. The dealcoholized silicone sealant has the characteristics of faster curing speed, good bonding performance, yellowing resistance and anti-bulging performance, less volatile organic compounds released in the curing process, better environmental protection and improved extrusion performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealant, and particularly relates to a dealcoholized silicone sealant and a preparation method thereof. BACKGROUND

[0002] The demand for dealcoholized silicone sealant is increasing due to its green and environmentally friendly nature and wide bonding properties. However, compared with dealcoholized silicone sealant, dealcoholized silicone sealant has low crosslinking activity, resulting in slow curing speed, which has been criticized, especially under low temperature conditions, which can cause a significant extension of the curing time or even complete curing failure.

[0003] Currently, the curing speed of dealcoholized silicone sealant can be improved to some extent by end-capping 107 glue technology. The end-capping 107 glue technology refers to using trialkoxysilane or tetraalkoxysilane as an end-capping agent to condense with the hydroxyl group at the end of 107 glue, thereby changing the low-activity monohydroxyl group at the end of 107 glue to a double-alkoxyl or trialkoxyl group with higher activity, and then improving the curing speed of dealcoholized silicone sealant during crosslinking and curing. However, the dealcoholized silicone sealant using end-capping 107 glue technology still has the problem of drumming in some applications such as weather-resistant glue for large-size aluminum plate curtain walls, which limits the application and promotion of dealcoholized silicone sealant. Therefore, it is necessary to prepare a dealcoholized silicone sealant with higher curing speed. SUMMARY

[0004] The present application aims to provide a dealcoholized silicone sealant that can be quickly cured.

[0005] The above-mentioned objectives are achieved by the following technical solutions.

[0006] The present application provides a dealcoholized silicone sealant in the first aspect, which comprises the following components by weight:

[0007]

[0008]

[0009] The multi-alkoxy end-capping 107 glue is obtained by first subjecting 107 glue to amino silane end-capping modification reaction with amino silane to obtain amino silane end-capping modified 107 glue, and then subjecting the amino silane end-capping modified 107 glue to multi-alkoxy end-capping reaction with epoxy silane.

[0010] In some embodiments, the amino silane is at least one of gamma-aminopropyl trimethoxysilane, gamma-aminopropyl triethoxysilane, N-(beta-aminoethyl)-gamma-aminopropyl trimethoxysilane, and N-(beta-aminoethyl)-gamma-aminopropyl triethoxysilane; and / or,

[0011] The epoxy silane is at least one of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0012] In some embodiments, the weight ratio of the 107 glue, the amino silane and the epoxy silane is 100:2-10:2-10; preferably, the weight ratio of the 107 glue, the amino silane and the epoxy silane is 100:3-5:3-5.

[0013] Preferably, in some embodiments, the dealcoholized silicone sealant comprises the following components by weight parts:

[0014]

[0015] More preferably, in some embodiments, the dealcoholized silicone sealant comprises the following components by weight parts:

[0016]

[0017] In some embodiments, the preparation method of the multi-alkoxy terminated 107 glue comprises the following steps:

[0018] The dehydrated 107 glue is subjected to an amino silane end-capping modification reaction with the amino silane under the action of a catalyst to obtain the amino silane end-capping modified 107 glue;

[0019] The obtained amino silane end-capping modified 107 glue is subjected to a multi-alkoxy end-capping reaction with an epoxy silane to obtain the multi-alkoxy terminated 107 glue.

[0020] In some embodiments, the amino silane end-capping modification reaction is sequentially carried out in an acid catalyst and a base catalyst; preferably, the weight ratio of the 107 glue, the acid catalyst and the base catalyst is 100:0.02-0.05:0.02-0.06; and / or,

[0021] The acid catalyst is at least one of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid; more preferably, the acid catalyst is acetic acid; and / or,

[0022] The base catalyst is at least one of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, tert-butylamine, isopropylamine.

[0023] In some embodiments, the catalytic reaction with the addition of the acid catalyst is stirred for 60-120 minutes in an inert gas environment at a temperature of 60-90°C; and / or, the catalytic reaction with the addition of the base catalyst is stirred for 60-120 minutes in an inert gas environment at a temperature of 60-90°C.

[0024] In some embodiments, the dehydration treatment of the 107 glue comprises the following steps: dehydration at 90-110°C and -0.080 to -0.099 MPa for 60-120 minutes; and / or,

[0025] Before the amino silane end-capped modified 107 glue is reacted with the epoxy silane, the obtained amino silane end-capped modified 107 glue is further treated at a temperature of 130-160°C and a vacuum degree of -0.090 to -0.099 MPa for 60-120 minutes.

[0026] In some embodiments, the multi-alkoxy end-capping reaction comprises the following steps: stirring the obtained amino silane end-capped modified 107 glue with the epoxy silane in an inert gas environment at a temperature of 60-90°C for 60-180 minutes to obtain the multi-alkoxy end-capped 107 glue.

[0027] In some embodiments, the 107 glue is α,ω-dihydroxypolydimethylsiloxane, and the viscosity at 25°C is 10-100 Pa·s; and / or,

[0028] The amino silane is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane; and / or,

[0029] The epoxy silane is at least one of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; and / or,

[0030] The dimethyl silicone oil has a viscosity of 0.1-0.5 Pa·s at 25°C; and / or,

[0031] The reinforcing filler is at least one of nano active calcium carbonate, heavy calcium carbonate, silica powder, and diatomite; and / or,

[0032] The crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane, and phenyltrimethoxysilane; and / or,

[0033] the coupling agent is at least one of γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane; and / or,

[0034] the catalyst is a titanate catalyst; preferably, the catalyst is at least one of tetraisopropyl titanate, tetrabutyl titanate, diisopropyl titanate bis(acetoacetate), dibutoxy bis(acetoacetate) titanate, diisobutyl titanate bis(acetoacetate).

[0035] The second aspect of the present application provides a preparation method of the dealcoholized silicone sealant as described above, comprising the following steps:

[0036] The polyalkoxy-terminated 107 glue, dimethyl silicone oil and reinforcing filler are blended under vacuum at a temperature of 80-130℃ for 60-180min;

[0037] After cooling to 40-50℃, the crosslinking agent, coupling agent and catalyst are added, and the reaction is stirred under vacuum for 40-120min to obtain the dealcoholized silicone sealant.

[0038] In the present application, the 107 glue is first modified by amino silane to obtain amino silane-terminated modified 107 glue, and then the polyalkoxy-terminated 107 glue is obtained by reacting epoxy silane with the amino silane-terminated modified 107 glue, which can introduce more alkoxy groups into the 107 glue to obtain the polyalkoxy-terminated 107 glue. When the polyalkoxy-terminated 107 glue is used as a base polymer, the dealcoholized silicone sealant prepared therefrom has the characteristics of faster curing speed, and has good bonding performance, yellowing resistance and anti-bulging performance, releases less volatile organic compounds during the curing process, is more environmentally friendly, and also has improved extrusion performance, and has good application prospects in building curtain wall adhesives. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application will be described more fully below. The present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive.

[0040] The experimental methods in the following examples not specified in the specific conditions are generally carried out according to the conventional conditions or according to the conditions recommended by the manufacturers. The various common chemical reagents used in the examples are all commercially available products.

[0041] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0042] This invention provides a dealcoholized silicone sealant, which, by weight, comprises the following components:

[0043]

[0044] The polyalkoxy-terminated 107 adhesive is obtained by first subjecting the 107 adhesive to an aminosilane-terminated modification reaction to obtain an aminosilane-terminated modified 107 adhesive, and then treating the aminosilane-terminated modified 107 adhesive with an epoxy silane.

[0045] The inventors discovered that by first modifying 107 adhesive with aminosilane to obtain aminosilane-terminated 107 adhesive, and then reacting it with epoxy silane to obtain polyalkoxy-terminated 107 adhesive, more alkoxy groups can be introduced into 107 adhesive to obtain polyalkoxy-terminated 107 adhesive. When this polyalkoxy-terminated 107 adhesive is used as the base polymer, the prepared de-alcoholized silicone sealant has the characteristics of faster curing speed, as well as good adhesion, yellowing resistance and anti-blistering properties. The amount of volatile organic compounds released during the curing process is less, making it more environmentally friendly. At the same time, it also has improved extrusion performance, that is, the overall effect is better, and it has a good application prospect in building curtain wall adhesives.

[0046] The corresponding reaction process for preparing this polyalkoxy-terminated 107 adhesive is shown below:

[0047]

[0048]

[0049] Wherein, R is γ-aminopropyl or N-(β-aminoethyl)-γ-aminopropyl, Ro is γ-glycidyl etheroxypropyl or 2-(3,4-epoxycyclohexyl)ethyl, and R1 is methyl or ethyl.

[0050] Furthermore, the type of acid catalyst also has a significant impact on the end-capping modification method. When acetic acid is used as the acid catalyst, the catalytic effect is the best, and the polyalkoxy-terminated 107 adhesive synthesized as the base polymer produces the best-performing dealcoholized silicone sealant.

[0051] The following are specific embodiments of the present invention.

[0052] Example 1

[0053] The present example provides a dealcoholized silicone sealant, and a preparation method thereof, which comprises the following steps:

[0054] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20 Pa·s was added into a reaction kettle, and dehydrated at 90°C and -0.099 MPa for 90 min, and then cooled to 80°C. 3 parts of γ-aminopropyltrimethoxysilane and 0.030 parts of acetic acid were added into the reaction kettle, and stirred for 60 min under nitrogen. 0.035 parts of t-butylamine was added for neutralization and stirring for 90 min. The reaction kettle was heated to 160°C, and vacuumed to -0.099 MPa to remove low-boiling substances for 90 min, to obtain an amino-silane end-capped modified 107 glue material. Then, nitrogen was introduced to release the pressure, and the material was cooled to 80°C under nitrogen atmosphere, and 4 parts of γ-glycidyl ether oxypropyltrimethoxysilane was added. After sufficient stirring for 120 min, a multi-alkoxy end-capped 107 glue was obtained.

[0055] The corresponding reaction process for preparing the multi-alkoxy end-capped 107 glue is shown as follows:

[0056]

[0057]

[0058] wherein, R is γ-aminopropyl, Ro is γ-glycidyl ether oxypropyl, and R1 is methyl.

[0059] 100 parts of the multi-alkoxy end-capped 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25°C, and 160 parts of nano active calcium carbonate were dehydrated and blended at a temperature of 110°C and a vacuum degree of -0.098 MPa for 120 min. After being cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts of titanium diisopropyl bis(acetoacetate) were added, and mixed and reacted at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 min, to obtain a fast-curing dealcoholized silicone sealant.

[0060] Example 2

[0061] The present example provides a dealcoholized silicone sealant, which is different from example 1 in that the 107 glue is first end-capped with an epoxy-silane, and then end-capped with an amino-silane. The preparation method thereof comprises the following steps:

[0062] Into a reaction kettle, 100 parts of 107 gum (alpha, omega-dihydroxypolydimethylsiloxane) with a viscosity of 20 Pa-s was added, and dehydrated at 90°C and -0.099 MPa for 90 min, and cooled to 80°C. 4 parts of gamma-glycidoxypropyltrimethoxysilane and 0.030 parts of acetic acid were added into the reaction kettle, and stirred for 60 min under nitrogen. 0.035 parts of t-butylamine was added, and stirred for 90 min for neutralization. The reaction kettle was heated to 160°C, and vacuumed to -0.099 MPa to remove low-boiling substances for 90 min, to obtain an amino-silane terminated modified 107 gum. Then, nitrogen was introduced to release the pressure, and the material was cooled to 80°C under nitrogen atmosphere, and 3 parts of gamma-aminopropyltrimethoxysilane was added. After stirring for 120 min, a multi-alkoxy terminated 107 gum was obtained.

[0063] Into a reaction kettle, 100 parts of the multi-alkoxy terminated 107 gum, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa-s at 25°C, and 160 parts of nano active calcium carbonate were added, and dehydrated and blended at 110°C and -0.098 MPa for 120 min. After being cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane, and 4 parts of titanium diisopropylate bis(acetoacetate) were added, and mixed and reacted at -0.098 MPa and 300 rpm for 80 min, to obtain a fast-curing de-alcoholized silicone sealant.

[0064] Example 3

[0065] This example provides a de-alcoholized silicone sealant, which is different from Example 1 in that the acid catalyst used is hydrochloric acid.

[0066] Example 4

[0067] This example provides a de-alcoholized silicone sealant, which is different from Example 1 in that the acid catalyst used is sulfuric acid.

[0068] Example 5

[0069] This example provides a de-alcoholized silicone sealant, which is different from Example 1 in that the acid catalyst used is phosphoric acid.

[0070] Example 6

[0071] This example provides a de-alcoholized silicone sealant, and the preparation method thereof comprises the following steps:

[0072] Into a reaction kettle, 100 parts of 107 gum (alpha, omega-dihydroxypolydimethylsiloxane) with viscosity of 10 Pa-s was added, and dehydrated at 110°C and -0.080 MPa for 60 min, and then cooled to 60°C. 8 parts of gamma-aminopropyltriethoxysilane and 0.05 parts of acetic acid were added into the reaction kettle, and stirred for 120 min under nitrogen. 0.05 parts of isopropylamine was added for neutralization, and stirred for 120 min. The reaction kettle was heated to 150°C, and vacuumed to -0.090 MPa to remove low boiling point substances for 60 min, to obtain an amino-silane terminated modified 107 gum. Then, nitrogen was introduced to release the pressure, and the material was cooled to 70°C under nitrogen atmosphere. 4 parts of gamma-glycidyloxypropyltriethoxysilane was added, and stirred for 180 min to obtain a multi-alkoxy terminated 107 gum.

[0073] Into a reaction kettle, 100 parts of the multi-alkoxy terminated 107 gum, 10 parts of dimethyl silicone oil with viscosity of 0.50 Pa-s, and 300 parts of nano active calcium carbonate were added, and dehydrated and blended at 130°C and -0.090 MPa for 90 min. After being cooled to 50°C, 1 part of methyltriethoxysilane, 0.2 parts of gamma-aminopropyltrimethoxysilane, and 6 parts of dibutoxybis(acetoacetoxyethyl) titanate were added, and mixed for 40 min at -0.080 MPa and 800 rpm to obtain a fast-curing dealcoholized silicone sealant.

[0074] Example 7

[0075] The present example provides a dealcoholized silicone sealant, and a preparation method thereof includes the following steps:

[0076] Into a reaction kettle, 100 parts of 107 gum (alpha, omega-dihydroxypolydimethylsiloxane) with viscosity of 10 Pa-s was added, and dehydrated at 110°C and -0.080 MPa for 60 min, and then cooled to 60°C. 8 parts of gamma-aminopropyltriethoxysilane and 0.05 parts of acetic acid were added into the reaction kettle, and stirred for 120 min under nitrogen. 0.05 parts of isopropylamine was added for neutralization, and stirred for 120 min. The reaction kettle was heated to 150°C, and vacuumed to -0.090 MPa to remove low boiling point substances for 60 min, to obtain an amino-silane terminated modified 107 gum. Then, nitrogen was introduced to release the pressure, and the material was cooled to 70°C under nitrogen atmosphere. 4 parts of gamma-glycidyloxypropyltriethoxysilane was added, and stirred for 180 min to obtain a multi-alkoxy terminated 107 gum.

[0077] 100 parts of the polyalkoxyl terminated 107 glue, 50 parts of dimethyl silicone oil with viscosity of 0.1 Pa·s at 25℃ and 150 parts of heavy calcium carbonate are blended under the conditions of temperature of 80℃ and vacuum degree of -0.099 MPa for 180 min, and after being cooled to 40℃, 0.5 parts of propyl trimethoxysilane, 0.8 parts of γ-glycidyloxypropyl trimethoxysilane and 3 parts of titanium diisobutoxide bis(acetoacetate) are added, and mixed and reacted under the conditions of vacuum degree of -0.090 MPa and stirring speed of 100 rpm for 120 min, to obtain the fast-curing dealcoholized silicone sealant.

[0078] Example 8

[0079] The present example provides a dealcoholized silicone sealant, and a preparation method thereof includes the following steps:

[0080] 100 parts of 107 glue (α, ω-dihydroxypolydimethylsiloxane) with viscosity of 50 Pa·s are added into a reaction kettle, and are blended under the conditions of temperature of 105℃ and vacuum degree of -0.095 MPa for 60 min, and after being cooled to 70℃, 5 parts of N-(β-aminoethyl)-γ-aminopropyl triethoxysilane and 0.04 parts of acetic acid are added, and are stirred under the condition of nitrogen for 100 min, and 0.03 parts of sodium hydroxide is added and stirred for 90 min of neutralization. The reaction kettle is heated to 160℃, and is vacuumed to -0.099 MPa to remove low-boiling substances for 120 min, to obtain an amino silane terminated modified 107 glue material. Then, nitrogen is introduced to release pressure, and the material is cooled to 60℃ under the nitrogen atmosphere, and 4.5 parts of γ-glycidyloxypropyl trimethoxysilane is added, and is fully stirred for 150 min, to obtain a polyalkoxyl terminated 107 glue.

[0081] 100 parts of the polyalkoxyl terminated 107 glue, 30 parts of dimethyl silicone oil with viscosity of 0.35 Pa·s at 25℃ and 220 parts of silica powder are blended under the conditions of temperature of 100℃ and vacuum degree of -0.095 MPa for 150 min, and after being cooled to 40℃, 0.8 parts of octyl trimethoxysilane, 0.3 parts of γ-mercaptopropyl trimethoxysilane and 5 parts of titanium tetraisopropoxide are added, and mixed and reacted under the conditions of vacuum degree of -0.095 MPa and stirring speed of 500 rpm for 100 min, to obtain the fast-curing dealcoholized silicone sealant.

[0082] Comparative Example 1

[0083] The present comparative example provides a dealcoholized silicone sealant, and compared with Example 1, the difference is that only the amino silane terminated modification reaction is performed, and the polyalkoxyl terminated reaction of the epoxy silane is not performed. A preparation method thereof includes the following steps:

[0084] Into a reaction kettle, 100 parts of 107 gum (α, ω-dihydroxypolydimethylsiloxane) with a viscosity of 20 Pa-s was added, and dehydrated at 90°C and -0.099 MPa for 90 min, and cooled to 80°C. 3 parts of γ-aminopropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reaction kettle, and stirred for 60 min under nitrogen. 0.035 parts of t-butylamine was added and stirred for 90 min for neutralization. The reaction kettle was heated to 160°C, and vacuumed to -0.099 MPa to remove low-boiling substances for 90 min. An alkoxy-terminated 107 gum was obtained.

[0085] Into a reaction kettle, 100 parts of the alkoxy-terminated 107 gum, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa-s at 25°C, and 160 parts of nano active calcium carbonate were added, and dehydrated and blended at 110°C and -0.098 MPa for 120 min. After being cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts of titanium diisopropoxide bis(acetoacetate) were added, and mixed and reacted at -0.098 MPa and 300 rpm for 80 min to obtain a dealcoholized silicone sealant 1.

[0086] Comparative Example 2

[0087] The present comparative example provides a dealcoholized silicone sealant, which is different from Example 2 in that only a polyalkoxy-terminated reaction of an epoxy silane is performed, and a terminal modification reaction of an amino silane is not performed. The preparation method thereof includes the following steps:

[0088] Into a reaction kettle, 100 parts of 107 gum (α, ω-dihydroxypolydimethylsiloxane) with a viscosity of 20 Pa-s was added, and dehydrated at 90°C and -0.099 MPa for 90 min, and cooled to 80°C. 3 parts of γ-aminopropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reaction kettle, and stirred for 60 min under nitrogen. 0.035 parts of t-butylamine was added and stirred for 90 min for neutralization. The reaction kettle was heated to 160°C, and vacuumed to -0.099 MPa to remove low-boiling substances for 90 min. An alkoxy-terminated 107 gum was obtained.

[0089] 100 parts of the alkoxy-terminated 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25℃ and 160 parts of nano active calcium carbonate are dehydrated and blended under the condition of a temperature of 110℃ and a vacuum degree of -0.098 MPa for 120 min, and after being fully cooled to 45℃, 0.6 parts of methyl trimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane and 4 parts of titanium diisopropylate bis(acetoacetic acid ethyl ester) are mixed and reacted under the condition of a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 min, to obtain the dealcoholized silicone sealant 2.

[0090] Comparative Example 3

[0091] The present comparative example provides a dealcoholized silicone sealant, which is compared with Example 1, and the difference is that amino silane and epoxy silane are simultaneously added to the 107 glue for modification reaction, and the preparation method comprises the following steps:

[0092] 100 parts of 107 glue (α, ω-dihydroxypolydimethylsiloxane) with a viscosity of 20 Pa·s are added to a reaction kettle, and dehydrated under the condition of 90℃ and -0.099 MPa for 90 min, and cooled to 80℃. 3 parts of γ-aminopropyl trimethoxysilane, 4 parts of γ-glycidyl ether propyl trimethoxysilane and 0.030 parts of acetic acid are added to the reaction kettle, and stirred under the condition of nitrogen for 60 min; 0.035 parts of tert-butylamine are added for stirring and neutralization for 90 min. The reaction kettle is heated to 160℃, and vacuumed to -0.099 MPa to remove low-boiling substances for 90 min. A multi-alkoxy-terminated 107 glue is obtained.

[0093] 100 parts of the alkoxy-terminated 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25℃ and 160 parts of nano active calcium carbonate are dehydrated and blended under the condition of a temperature of 110℃ and a vacuum degree of -0.098 MPa for 120 min, and after being fully cooled to 45℃, 0.6 parts of methyl trimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane and 4 parts of titanium diisopropylate bis(acetoacetic acid ethyl ester) are mixed and reacted under the condition of a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 min, to obtain the dealcoholized silicone sealant 2.

[0094] Comparative Example 4

[0095] The present comparative example provides a dealcoholized silicone sealant, which is compared with Example 1, and the difference is that ordinary 107 glue is used to prepare the dealcoholized silicone sealant, and the preparation method comprises the following steps:

[0096] Take 100 parts of 107 glue with a viscosity of 20 Pa·s, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25℃, and 160 parts of nano active calcium carbonate. Dehydrate and blend under the condition of a temperature of 110℃ and a vacuum degree of-0.098 MPa for 120 min. After fully cooling to 45℃, add 0.6 parts of methyl trimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, and 4 parts of titanium diisopropyl bis(acetylacetate) oxide. Mix and react under the condition of a vacuum degree of-0.098 MPa and a stirring speed of 300 rpm for 80 min to obtain the dealcoholized silicone sealant 4.

[0097] Test the performance of the dealcoholized silicone sealant prepared in the above examples and comparative examples, and the test results are shown in Table 1. In Table 1, the performance test methods of the samples are as follows:

[0098] 1. The tack-free time is detected according to the B method of GB / T 13477.5-2002 “Test methods for building seals Part 5: Determination of tack-free time”;

[0099] 2. 24h curing depth (mm) detection: take two square glass pieces with a side length of 50 mm. After the surface is washed with ethanol and dried, a glue lump is made on one of the glass pieces. Another glass piece is pressed on the glue lump to make the upper and lower glass pieces parallel, and the distance between the two is controlled to be 6 mm. Use a scraper to remove the glue on the edges of the two parallel glass pieces and ensure that the glue surface is flat. After the test piece is placed in an environment of 23℃ and 50% RH for 24 h, the glue is cut along the parallel surface. After removing the uncured glue, the thickness of the cured glue around the edges of the test piece is measured, and the average value is taken as the 24h curing depth value.

[0100] 3. Extrudability is tested according to the provisions of 8.2 in GB / T 13477.3-2017 “Test methods for building seals Part 3: Method for determining the extrudability of sealants using standard apparatus”.

[0101] 4. Tensile bonding strength and elongation at break are detected according to GB / T 13477 “Building seals Part 8: Determination of tensile bonding”;

[0102] 5. Anti-bulging performance test:

[0103] a) Aluminum plate curtain wall: single piece size is 2000 mm x 1500 mm, glue joint width is 16 mm, and glue joint depth is 8 mm.

[0104] b) Gluing environment: the maximum air temperature is 21℃ and the relative humidity is 40% during the day, and the minimum temperature is 5℃ and the relative humidity is 15% at night.

[0105] c) Test method: The glue was applied at about 7:00 am on the first day, and after 24 h, the glue joint was observed for blistering.

[0106] 6. The yellowing resistance was detected according to GB / T 13477.21-2022 "Building Sealing Material Test Methods Part 21: Determination of Color Change after Artificial Accelerated Climate Aging".

[0107] 7. The total volatile organic content was detected according to Appendix F of GB 18583-2008.

[0108] Table 1 Properties of the Dealcoholized Silicone Sealant

[0109]

[0110]

[0111] As shown in Table 1, according to the results of Examples 1-8, the amino silane end-capped modified 107 glue was first obtained by end-capping modification of 107 glue with amino silane, and then the multi-alkoxy end-capped 107 glue was obtained by reaction of the amino silane end-capped modified 107 glue with epoxy silane, which could introduce more alkoxy groups into the 107 glue to obtain the multi-alkoxy end-capped 107 glue. When the multi-alkoxy end-capped 107 glue was used as the base polymer, the dealcoholized silicone sealant prepared therefrom had the characteristics of faster curing speed, and had good bonding performance, yellowing resistance and anti-bubbling performance, and released less volatile organic compounds during the curing process, was more environmentally friendly, and also had improved extrusion performance. According to the comparison of Example 1 and Examples 3-5, the acetic acid was used as the acid catalyst, and the catalytic effect was the best. The dealcoholized silicone sealant prepared by using the multi-alkoxy end-capped 107 glue synthesized therefrom as the base polymer had the best performance. According to the comparison of Example 1 and Example 2, the end-capping sequence could affect the performance of the dealcoholized silicone sealant. The performance of the multi-alkoxy end-capped 107 glue prepared by first end-capping with epoxy silane and then end-capping with amino silane in Example 2 was poorer than that of the multi-alkoxy end-capped 107 glue prepared by first end-capping with amino silane and then end-capping with epoxy silane in Example 1.

[0112] According to the comparison of Example 1 and Comparative Example 3, compared with the method of adding amino silane and epoxy silane at the same time for modification reaction of 107 glue, the method of first end-capping modification of 107 glue with amino silane to obtain amino silane end-capped modified 107 glue, and then reacting the amino silane end-capped modified 107 glue with epoxy silane, could introduce more alkoxy groups, and the prepared multi-alkoxy end-capped 107 glue had better effect, and the corresponding dealcoholized silicone sealant composition had better comprehensive performance.

[0113] Comparing Example 1 and Comparative Example 4, it can be seen that the dealcoholized silicone sealant prepared from common 107 glue has a long surface dry time, is not tack-free after 24 h curing, has a small curing depth, low mechanical strength, poor anti-bulging effect, and poor yellowing resistance, and the additive in the system is not completely reacted, and the total volatile organic content is high. Comparing Example 1 and Comparative Examples 1 and 2, it can be seen that when the 107 glue is modified by amino silane or epoxy silane end-capping, the curing speed of the dealcoholized silicone sealant prepared therefrom is improved, but the sample surface is slightly sticky after 24 h, which may be due to the relatively small amount of additive, which does not allow the system to be completely cross-linked; the mechanical properties of the sample are improved, the yellowing resistance is improved, and the total volatile organic content is reduced, but the anti-bulging test still causes bulging. When the multi-alkoxy end-capped 107 glue of the present application is used as the base polymer, the curing speed of the dealcoholized silicone sealant prepared therefrom is greatly improved, the surface dry time is significantly shortened, the curing depth is significantly improved, and it is comparable to or even better than the dealcoholized silicone sealant; moreover, the sample is completely tack-free after 24 h curing, and the mechanical strength of the sample is significantly improved after sufficient curing; the anti-bulging effect is good, the yellowing resistance and extrusion performance are also significantly improved, which is more conducive to improving the construction efficiency, and the total volatile organic content is significantly reduced due to the small amount of additive in the system, which is more environmentally friendly.

[0114] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not conflict, they should be considered within the scope of the present disclosure.

[0115] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be construed as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A dealcoholized silicone sealant, characterized by, The dealcoholized silicone sealant comprises the following components by weight parts: The multi-alkoxy terminated 107 glue is obtained by carrying out an amino silane end modification reaction on the 107 glue by using an amino silane, and then carrying out a multi-alkoxy end modification reaction on the amino silane end modification 107 glue by using an epoxy silane.

2. The dealcoholized silicone sealant of claim 1, wherein, The amino silane is at least one of γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyl triethoxysilane; and / or, The epoxy silane is at least one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, and 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane.

3. The dealcoholized silicone sealant of claim 1, wherein, The weight ratio of the 107 glue, the amino silane, and the epoxy silane is 100:2-10:2-10.

4. The dealcoholized silicone sealant of claim 3, wherein, The weight ratio of the 107 glue, the amino silane, and the epoxy silane is 100:3-5:3-5.

5. The dealcoholized silicone sealant according to any one of claims 1 to 4, wherein The preparation method of the multi-alkoxy terminated 107 glue comprises the following steps: The amino silane end modification reaction is carried out on the dehydrated 107 glue by using an amino silane under the action of a catalyst to obtain the amino silane end modification 107 glue; The multi-alkoxy end modification reaction is carried out on the obtained amino silane end modification 107 glue by using an epoxy silane to obtain the multi-alkoxy terminated 107 glue.

6. The dealcoholized silicone sealant of claim 5, wherein, The amino silane end modification reaction is carried out in an acid catalyst and a base catalyst in sequence.

7. The dealcoholized silicone sealant of claim 6, wherein, The weight ratio of the 107 glue, the acid catalyst, and the base catalyst is 100:0.02-0.05:0.02-0.06; and / or, The acid catalyst is at least one of hydrochloric acid, sulfuric acid, phosphoric acid, and acetic acid; and / or, The base catalyst is at least one of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, tert-butylamine, and isopropylamine.

8. The dealcoholized silicone sealant of claim 7, wherein, The acid catalyst is acetic acid.

9. The dealcoholized silicone sealant of claim 6, wherein, The catalytic reaction of adding the acid catalyst is stirred for 60-120 min in an inert gas environment at a reaction temperature of 60-90°C; and / or, the catalytic reaction of adding the base catalyst is stirred for 60-120 min in an inert gas environment at a reaction temperature of 60-90°C.

10. The dealcoholized silicone sealant of claim 5, wherein, The dehydration treatment of the 107 glue comprises the following steps: dehydration at 90-110°C and -0.080-0.099 MPa for 60-120 min; and / or, Before the reaction of the amino silane end modification 107 glue and the epoxy silane, the obtained amino silane end modification 107 glue is further treated at a temperature of 130-160°C and a vacuum degree of -0.090-0.099 MPa for 60-120 min.

11. The dealcoholized silicone sealant of claim 5, wherein, The multi-alkoxy end modification reaction comprises the following steps: stirring the obtained amino silane end modification 107 glue and the epoxy silane in an inert gas environment at a temperature of 60-90°C for 60-180 min to obtain the multi-alkoxy terminated 107 glue.

12. The dealcoholized silicone sealant of any one of claims 1-4, wherein, The 107 glue is α, ω-dihydroxy polydimethylsiloxane, and the viscosity at 25°C is 10 Pa·s-100 Pa·s; and / or, The amino silane is at least one of γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyl triethoxysilane; and / or, The epoxy silane is at least one of γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl triethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane; and / or, The dimethyl silicone oil has a viscosity of 0.1 Pa·s-0.5 Pa·s at 25°C; and / or, The reinforcing filler is at least one of nano active calcium carbonate, heavy calcium carbonate, silica powder, and diatomite; and / or, The cross-linking agent is at least one of methyl trimethoxysilane, methyl triethoxysilane, propyl trimethoxysilane, octyl trimethoxysilane, and phenyl trimethoxysilane; and / or, The coupling agent is at least one of γ-aminopropyl trimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, γ-glycidyloxypropyl trimethoxysilane, and γ-mercaptopropyl trimethoxysilane; and / or, The catalyst is a titanate catalyst.

13. The dealcoholized silicone sealant of claim 12, wherein, The catalyst is at least one of tetraisopropyl titanate, tetrabutyl titanate, diisopropyl titanate di(acetoacetate), dibutoxy bis(acetoacetate) titanate, and diisobutyl titanate di(acetoacetate).

14. A process for the preparation of the dealcoholized silicone sealant according to any one of claims 1 to 13, characterized in that, The method comprises the following steps: The polyalkoxy-terminated 107 glue, the dimethyl silicone oil, and the reinforcing filler are dehydrated and blended under vacuum at a temperature of 80°C-130°C for 60 min-180 min; After cooling to 40°C-50°C, the cross-linking agent, the coupling agent, and the catalyst are added, and the reaction is stirred under vacuum for 40 min-120 min to obtain the dealcoholized silicone sealant.

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