Dealcoholized silicone sealant and preparation method thereof

Abstract

The invention belongs to the technical field of sealants, and discloses a dealcoholized silicone sealant and a preparation method thereof, the dealcoholized silicone sealant comprises the following components by weight: 100 parts of a polyalkoxy terminated 107 adhesive, 10-50 parts of dimethyl silicone oil, 150-300 parts of a reinforcing filler, 0.5-1 part of a cross-linking agent, 0.2-0.8 part of a coupling agent, and 3-6 parts of a catalyst; wherein the polyalkoxy terminated 107 glue is obtained by firstly carrying out amino silane terminated modification reaction on 107 glue through amino silane to obtain amino silane terminated modified 107 glue and then carrying out polyalkoxy terminated reaction on the amino silane terminated modified 107 glue through epoxy silane. The dealcoholized silicone sealant has the characteristic of higher curing speed, has good adhesive property, yellowing resistance and bulging resistance, releases less volatile organic compounds in the curing process, is more environment-friendly, and also has improved extrusion performance.

Description

Technical Field

[0001] The invention belongs to the technical field of sealants, and in particular relates to a dealcoholized silicone sealant and a preparation method thereof. Background Art

[0002] The demand for dealcoholized silicone sealants is increasing due to their environmental friendliness and wide range of adhesive properties. However, compared with dealcoholized oxime silicone sealants, dealcoholized silicone sealants have been criticized for their low cross-linking activity, which leads to slow curing speed. Especially under low temperature conditions, the curing time will be greatly extended or even incomplete curing.

[0003] At present, the curing speed of dealcoholized silicone sealants can be improved to a certain extent through the end-capping 107 glue technology. The end-capping 107 glue technology refers to the use of trialkoxysilane or tetraalkoxysilane as a capping agent, through the condensation reaction of the alkoxy group and the hydroxyl group at the end of the 107 glue, the end of the 107 glue is changed from a low-activity monohydroxyl group to a dialkoxy or trialkoxy group with higher activity, and then the curing speed of the dealcoholized silicone sealant is improved during the cross-linking and curing process. However, the dealcoholized silicone sealant using the end-capping 107 glue technology still has the problem of bulging in some applications such as weather-resistant glue for large-size aluminum curtain walls due to the problem of curing speed, which limits the application and promotion of dealcoholized silicone sealants. Therefore, it is necessary to prepare a dealcoholized silicone sealant with a higher curing speed. Summary of the invention

[0004] The object of the present invention is to provide a fast-curing dealcoholized silicone sealant.

[0005] The above-mentioned purpose is achieved by the following technical solutions.

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

[0007]

[0008]

[0009] The polyalkoxy-terminated 107 glue is obtained by first subjecting 107 glue to an aminosilane-terminated modification reaction to obtain aminosilane-terminated modified 107 glue, and then subjecting the aminosilane-terminated modified 107 glue to a polyalkoxy-terminated reaction with epoxysilane.

[0010] In some embodiments, the aminosilane is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane; and / or,

[0011] The epoxysilane is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

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

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

[0014]

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

[0016]

[0017] In some embodiments, the method for preparing the polyalkoxy-terminated 107 glue comprises the following steps:

[0018] The dehydrated 107 glue and aminosilane are subjected to an aminosilane end-capping modification reaction under the action of a catalyst to obtain the aminosilane end-capping modified 107 glue;

[0019] The obtained aminosilane-terminated modified 107 glue is subjected to a polyalkoxy-terminated reaction with epoxysilane to obtain the polyalkoxy-terminated 107 glue.

[0020] In some embodiments, the aminosilane end-capping modification reaction is carried out in an acid catalyst and a base catalyst in sequence; 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 and acetic acid; more preferably, the acid catalyst is acetic acid; and / or,

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

[0023] In some embodiments, the catalytic reaction of adding the acid catalyst is stirred for 60 min to 120 min in an inert gas environment, and the reaction temperature is 60°C to 90°C; and / or, the catalytic reaction of adding the base catalyst is stirred for 60 min to 120 min in an inert gas environment, and the reaction temperature is 60°C to 90°C.

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

[0025] Before the aminosilane-terminated modified 107 glue reacts with epoxy silane, the method further comprises treating the obtained aminosilane-terminated modified 107 glue at a temperature of 130° C. to 160° C. and a vacuum degree of -0.090 MPa to -0.099 MPa for 60 min to 120 min.

[0026] In some of the embodiments, the polyalkoxy-terminated reaction comprises the following steps: in an inert gas environment, stirring the obtained aminosilane-terminated modified 107 glue and epoxysilane at a temperature of 60° C. to 90° C. for 60 min to 180 min to obtain the polyalkoxy-terminated 107 glue.

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

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

[0029] The epoxysilane is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; and / or,

[0030] The viscosity of the dimethyl silicone oil at 25° C. is 0.1 Pa·s to 0.5 Pa·s; and / or,

[0031] The reinforcing filler is at least one of nano-active calcium carbonate, heavy calcium carbonate, silicon powder and diatomaceous earth; 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, and γ-mercaptopropyltrimethoxysilane; and / or,

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

[0035] A second aspect of the present invention provides a method for preparing the dealcoholized silicone sealant as described above, comprising the following steps:

[0036] Dehydrate and blend the polyalkoxy-terminated 107 glue, dimethyl silicone oil and reinforcing filler at a temperature of 80°C to 130°C under vacuum conditions for 60min to 180min;

[0037] After cooling to 40° C. to 50° C., a crosslinking agent, a coupling agent and a catalyst are added, and the mixture is stirred and reacted for 40 min to 120 min under vacuum conditions to obtain the dealcoholized silicone sealant.

[0038] In the present invention, 107 glue is first modified by aminosilane to obtain aminosilane-terminated modified 107 glue, and then epoxysilane is reacted with aminosilane-terminated modified 107 glue to obtain polyalkoxy-terminated 107 glue, so that more alkoxy groups can be introduced into 107 glue to obtain polyalkoxy-terminated 107 glue. When the polyalkoxy-terminated 107 glue is used as a base polymer, the prepared dealcoholized silicone sealant has the characteristics of faster curing speed, good bonding performance, yellowing resistance and anti-bulging performance, less volatile organic compounds released during the curing process, more environmentally friendly, and improved extrusion performance, and has a good application prospect in adhesives for building curtain walls. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented 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 disclosure of the present invention more thorough and comprehensive.

[0040] The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0041] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0042] The embodiment of the present invention provides a dealcoholized silicone sealant, which comprises the following components in parts by weight:

[0043]

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

[0045] Among them, the inventors found that 107 glue was first modified by aminosilane to obtain aminosilane-terminated modified 107 glue, and then epoxysilane and aminosilane-terminated modified 107 glue were reacted to obtain polyalkoxy-terminated 107 glue, which can introduce more alkoxy groups into 107 glue to obtain polyalkoxy-terminated 107 glue. When the polyalkoxy-terminated 107 glue is used as the base polymer, the prepared dealcoholized silicone sealant has the characteristics of faster curing speed, good adhesion, yellowing resistance and anti-bulging performance, less volatile organic compounds released during the curing process, more environmentally friendly, and improved extrusion performance, that is, the overall effect is better, and it has a good application prospect in adhesives for building curtain walls.

[0046] The corresponding reaction process for preparing the polyalkoxy-terminated 107 glue is as follows:

[0047]

[0048]

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

[0050] Furthermore, the type of acid catalyst also has a great influence on the end-capping modification method. When acetic acid is used as the acid catalyst, the catalytic effect is the best. The synthesized multi-alkoxy end-capped 107 glue is used as the base polymer, and the prepared dealcoholized silicone sealant has the best performance.

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

[0052] Example 1

[0053] This embodiment provides a dealcoholized silicone sealant, and the preparation method thereof comprises the following steps:

[0054] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20Pa·s were added to the reactor, dehydrated at 90℃, -0.099MPa for 90min, and cooled to 80℃. 3 parts of γ-aminopropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reactor, stirred for 60min under nitrogen; 0.035 parts of tert-butylamine were added for stirring and neutralization for 90min. The reactor was heated to 160℃ and evacuated to -0.099MPa to remove low-boiling substances for 90min to obtain aminosilane-terminated modified 107 glue material. Then, nitrogen was introduced to relieve the pressure, and the material was cooled to 80℃ under nitrogen atmosphere, and 4 parts of γ-glycidyloxypropyltrimethoxysilane were added. After being fully stirred for 120min, polyalkoxy-terminated 107 glue was obtained.

[0055] The corresponding reaction process for preparing the polyalkoxy-terminated 107 glue is as follows:

[0056]

[0057]

[0058] Among them, R is γ-aminopropyl, Ro is γ-glycidyloxypropyl, and R1 is methyl.

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

[0060] Example 2

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

[0062] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20Pa·s were added to the reactor, dehydrated at 90℃, -0.099MPa for 90min, and cooled to 80℃. 4 parts of γ-glycidyloxypropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reactor, stirred for 60min under nitrogen conditions; 0.035 parts of tert-butylamine were added for stirring and neutralization for 90min. The reactor was heated to 160℃ and evacuated to -0.099MPa to remove low-boiling substances for 90min to obtain aminosilane-terminated modified 107 glue material. Then, nitrogen was introduced to relieve the pressure, and the material was cooled to 80℃ under nitrogen atmosphere, and 3 parts of γ-aminopropyltrimethoxysilane were added. After being fully stirred for 120min, polyalkoxy-terminated 107 glue was obtained.

[0063] 100 parts of the polyalkoxy-terminated 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25°C and 160 parts of nano-activated calcium carbonate were dehydrated and blended at a temperature of 110°C and a vacuum degree of -0.098 MPa for 120 minutes. After being fully cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 4 parts of di(ethyl acetoacetate)titanate diisopropyl were added, and the mixture was mixed and reacted at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 minutes to obtain a fast-curing dealcoholized silicone sealant.

[0064] Example 3

[0065] This embodiment provides a dealcoholized silicone sealant, which is different from Embodiment 1 in that the acid catalyst used is hydrochloric acid.

[0066] Example 4

[0067] This embodiment provides a dealcoholized silicone sealant, which is different from Embodiment 1 in that the acid catalyst used is sulfuric acid.

[0068] Example 5

[0069] This embodiment provides a dealcoholized silicone sealant, which is different from Embodiment 1 in that the acid catalyst used is phosphoric acid.

[0070] Example 6

[0071] This embodiment provides a dealcoholized silicone sealant, and the preparation method thereof comprises the following steps:

[0072] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 10Pa·s were added to the reactor, dehydrated at 110℃, -0.080MPa for 60min, and cooled to 60℃. 8 parts of γ-aminopropyltriethoxysilane and 0.05 parts of acetic acid were added to the reactor, stirred for 120min under nitrogen conditions; 0.05 parts of isopropylamine were added for stirring and neutralization for 120min. The reactor was heated to 150℃ and evacuated to -0.090MPa to remove low-boiling substances for 60min to obtain aminosilane-terminated modified 107 glue material. Then, nitrogen was introduced to relieve the pressure, and the material was cooled to 70℃ under nitrogen atmosphere, and 4 parts of γ-glycidyloxypropyltriethoxysilane were added. After being fully stirred for 180min, polyalkoxy-terminated 107 glue was obtained.

[0073] 100 parts of the polyalkoxy-terminated 107 glue, 10 parts of dimethyl silicone oil with a viscosity of 0.50 Pa·s and 300 parts of nano-activated calcium carbonate are dehydrated and blended at a temperature of 130° C. and a vacuum degree of -0.090 MPa for 90 minutes. After being fully cooled to 50° C., 1 part of methyltriethoxysilane, 0.2 parts of γ-aminopropyltrimethoxysilane and 6 parts of dibutoxybis(ethyl acetoacetate) titanate are added, and the mixture is mixed and reacted for 40 minutes at a vacuum degree of -0.080 MPa and a stirring speed of 800 rpm to obtain a fast-curing dealcoholized silicone sealant.

[0074] Example 7

[0075] This embodiment provides a dealcoholized silicone sealant, and the preparation method thereof comprises the following steps:

[0076] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 100 Pa·s were added to the reactor, dehydrated at 100°C and -0.090 MPa for 120 min, and cooled to 90°C. 2 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 0.02 parts of acetic acid were added to the reactor and stirred for 90 min under nitrogen conditions; 0.02 parts of potassium hydroxide were added for stirring and neutralization for 60 min. The reactor was heated to 130°C and evacuated to -0.098 MPa to remove low-boiling substances for 120 min to obtain aminosilane-terminated modified 107 glue material. Then, nitrogen was introduced to relieve the pressure. After the material was cooled to 90°C under a nitrogen atmosphere, 2 parts of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) were added and stirred for 60 min to obtain polyalkoxy-terminated 107 glue.

[0077] 100 parts of the polyalkoxy-terminated 107 glue, 50 parts of dimethyl silicone oil with a viscosity of 0.1 Pa·s at 25°C and 150 parts of heavy calcium carbonate are dehydrated and blended at a temperature of 80°C and a vacuum degree of -0.099 MPa for 180 minutes. After being fully cooled to 40°C, 0.5 parts of propyltrimethoxysilane, 0.8 parts of γ-glycidyloxypropyltrimethoxysilane and 3 parts of di(ethyl acetoacetate) diisobutyl titanate) are added, and the mixture is mixed and reacted for 120 minutes at a vacuum degree of -0.090 MPa and a stirring speed of 100 rpm to obtain a fast-curing dealcoholized silicone sealant.

[0078] Example 8

[0079] This embodiment provides a dealcoholized silicone sealant, and the preparation method thereof comprises the following steps:

[0080] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 50Pa·s were added to the reactor, dehydrated at 105℃, -0.095MPa for 60min, and cooled to 70℃. 5 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane and 0.04 parts of acetic acid were added to the reactor, stirred for 100min under nitrogen conditions; 0.03 parts of sodium hydroxide were added for stirring and neutralization for 90min. The reactor was heated to 160℃ and evacuated to -0.099MPa to remove low-boiling substances for 120min to obtain aminosilane-terminated modified 107 glue material. Then, nitrogen was introduced to relieve the pressure, and the material was cooled to 60℃ under nitrogen atmosphere, and 4.5 parts of γ-glycidyloxypropyltrimethoxysilane were added. After being fully stirred for 150min, polyalkoxy-terminated 107 glue was obtained.

[0081] 100 parts of the polyalkoxy-terminated 107 glue, 30 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25°C and 220 parts of silicon powder are dehydrated and blended at a temperature of 100°C and a vacuum degree of -0.095 MPa for 150 minutes. After being fully cooled to 40°C, 0.8 parts of octyltrimethoxysilane, 0.3 parts of γ-mercaptopropyltrimethoxysilane and 5 parts of tetraisopropyl titanate are added, and the mixture is mixed and reacted for 100 minutes at a vacuum degree of -0.095 MPa and a stirring speed of 500 rpm to obtain a fast-curing dealcoholized silicone sealant.

[0082] Comparative Example 1

[0083] This comparative example provides a dealcoholized silicone sealant, which is different from Example 1 in that only the end-capping modification reaction of aminosilane is performed, and the polyalkoxy end-capping reaction of epoxysilane is not performed. The preparation method thereof comprises the following steps:

[0084] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20 Pa·s was added to the reactor, dehydrated at 90°C and -0.099 MPa for 90 minutes, and cooled to 80°C. 3 parts of γ-aminopropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reactor, stirred for 60 minutes under nitrogen; 0.035 parts of tert-butylamine were added and stirred for 90 minutes. The reactor was heated to 160°C and vacuumed to -0.099 MPa to remove low-boiling substances for 90 minutes. Alkoxy-terminated 107 glue was obtained.

[0085] 100 parts of the alkoxy-terminated 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25°C and 160 parts of nano-activated 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 fully cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 4 parts of di(ethyl acetoacetate) titanate were added, and the mixture was mixed and reacted for 80 min at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm to obtain a dealcoholized silicone sealant 1.

[0086] Comparative Example 2

[0087] This comparative example provides a dealcoholized silicone sealant, which is different from Example 2 in that only the polyalkoxy end-capping reaction of epoxysilane is performed, and the end-capping modification reaction of aminosilane is not performed. The preparation method thereof comprises the following steps:

[0088] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20 Pa·s was added to the reactor, dehydrated at 90°C and -0.099 MPa for 90 minutes, and cooled to 80°C. 4 parts of γ-glycidyloxypropyltrimethoxysilane and 0.030 parts of acetic acid were added to the reactor, stirred for 60 minutes under nitrogen; 0.035 parts of tert-butylamine were added and stirred for 90 minutes. The reactor was heated to 160°C and vacuumed to -0.099 MPa to remove low-boiling substances for 90 minutes. Alkoxy-terminated 107 glue 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°C and 160 parts of nano-activated 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 fully cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 4 parts of di(ethyl acetoacetate) titanate were added, and the mixture was mixed and reacted for 80 min at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm to obtain a dealcoholized silicone sealant 2.

[0090] Comparative Example 3

[0091] This comparative example provides a dealcoholized silicone sealant, which is different from Example 1 in that aminosilane and epoxysilane are added to 107 glue at the same time for modification reaction, and its preparation method includes the following steps:

[0092] 100 parts of 107 glue (α, ω-dihydroxy polydimethylsiloxane) with a viscosity of 20 Pa·s was added to the reactor, dehydrated at 90°C and -0.099 MPa for 90 minutes, and cooled to 80°C. 3 parts of γ-aminopropyl trimethoxysilane, 4 parts of γ-glycidyloxypropyl trimethoxysilane and 0.030 parts of acetic acid were added to the reactor and stirred for 60 minutes under nitrogen; 0.035 parts of tert-butylamine were added and stirred for 90 minutes. The reactor was heated to 160°C and vacuumed to -0.099 MPa to remove low-boiling substances for 90 minutes. Polyalkoxy-terminated 107 glue was obtained.

[0093] 100 parts of the polyalkoxy-terminated 107 glue, 40 parts of dimethyl silicone oil with a viscosity of 0.35 Pa·s at 25°C and 160 parts of nano-activated 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 fully cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 4 parts of di(ethyl acetoacetate) titanate were added, and the mixture was mixed and reacted at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 min to obtain a dealcoholized silicone sealant 3.

[0094] Comparative Example 4

[0095] This comparative example provides a dealcoholized silicone sealant. Compared with Example 1, the difference is that ordinary 107 glue is used to prepare the dealcoholized silicone sealant, and the preparation method thereof includes the following steps:

[0096] 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°C and 160 parts of nano-activated 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 fully cooled to 45°C, 0.6 parts of methyltrimethoxysilane, 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and 4 parts of di(ethyl acetoacetate) titanate were added, and the mixture was mixed and reacted at a vacuum degree of -0.098 MPa and a stirring speed of 300 rpm for 80 min to obtain dealcoholized silicone sealant 4.

[0097] The performance of the dealcoholized silicone sealants prepared in the above examples and comparative examples was tested, and the test results are shown in Table 1. The performance test method of the samples in Table 1 is as follows:

[0098] 1. The surface drying time shall be tested according to method B of GB / T 13477.5-2002 "Test methods for building sealing materials Part 5: Determination of surface drying time";

[0099] 2. 24h curing depth (mm) test: Take two square glass pieces with a side length of 50mm, clean the surface with ethanol and dry it, then put a glue ball on one of the glass pieces, press the other glass piece on the glue ball, make the upper and lower glass pieces parallel, and control the distance between them to be 6mm. Use a scraper to scrape away the overflowing glue around the edges of the two parallel glass pieces and ensure that the surface of the glue is flat. After curing the specimen in an environment of 23℃ and 50%RH for 24h, cut the glue along the parallel surface. After removing the uncured glue, measure the thickness of the cured glue around the edge of the specimen, and take the average value, which is the 24h curing depth value.

[0100] 3. The extrusion property shall be tested in accordance with the provisions of 8.2 of GB / T 13477.3-2017 "Test methods for building sealing materials Part 3: Method for determining the extrusion property of sealing materials using standard instruments".

[0101] 4. The tensile bond strength and elongation at break shall be tested according to GB / T 13477 "Building Sealing Materials - Part 8 - Determination of Tensile Bond";

[0102] 5. Anti-bulging performance test:

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

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

[0105] c) Test method: Start applying glue at around 7:00 am on the first day, and start observing the bulging of the glue seam after 24 hours.

[0106] 6. Yellowing resistance is tested in accordance with GB / T 13477.21-2022 "Test methods for building sealing materials - Part 21: Determination of color change after artificial accelerated weathering".

[0107] 7. The total volatile organic compound content shall be tested in accordance with Appendix F of GB 18583-2008.

[0108] Table 1 Properties of dealcoholized silicone sealant

[0109]

[0110]

[0111] As shown in Table 1, it can be seen from the results of Examples 1-8 that the 107 glue is first end-capped and modified by aminosilane to obtain the aminosilane end-capped and modified 107 glue, and then the polyalkoxy end-capped 107 glue is obtained by reacting epoxysilane with the aminosilane end-capped and modified 107 glue, which can introduce more alkoxy groups into the 107 glue to obtain the polyalkoxy end-capped 107 glue. When the polyalkoxy end-capped 107 glue is used as the base polymer, the prepared dealcoholized silicone sealant has the characteristics of faster curing speed, good bonding performance, yellowing resistance and anti-bulging performance, less volatile organic compounds released during the curing process, more environmentally friendly, and improved extrusion performance. It can be seen from the comparison between Example 1 and Examples 3-5 that the catalytic effect is best when acetic acid is used as the acid catalyst, and the prepared dealcoholized silicone sealant has the best performance when the synthesized polyalkoxy end-capped 107 glue is used as the base polymer. Comparison between Example 1 and Example 2 shows that the end-capping sequence affects the performance of dealcoholized silicone sealant. The performance of the polyalkoxy-end-capped 107 glue prepared by first end-capping with epoxy silane and then end-capping with amino silane in Example 2 is worse than that of the polyalkoxy-end-capped 107 glue prepared by first end-capping with amino silane and then end-capping with epoxy in Example 1.

[0112] From the comparison between Example 1 and Comparative Example 3, it can be seen that compared with the method of adding aminosilane and epoxysilane to 107 glue at the same time for modification reaction, the method of first modifying 107 glue by aminosilane end-capping to obtain aminosilane end-capped modified 107 glue, and then reacting epoxysilane with aminosilane end-capped modified 107 glue, which can introduce more alkoxy groups, the prepared multi-alkoxy end-capped 107 glue has better effect, and the corresponding dealcoholized silicone sealant composition has better comprehensive performance.

[0113] Comparison between Example 1 and Comparative Example 4 shows that the dealcoholized silicone sealant prepared from ordinary 107 glue has too little additive added, which affects the curing of the glue sample, has a long surface drying time, is not tack-free after 24 hours of curing, has a small curing depth, has low mechanical strength of the glue sample, has poor anti-bulging effect, and has poor yellowing resistance. The additives in the system have incomplete reaction and a high content of total volatile organic compounds. Comparison between Example 1 and Comparative Examples 1 and 2 shows that when 107 glue is modified by end-capping with aminosilane or epoxysilane, the curing speed of the prepared dealcoholized silicone sealant is improved, but the surface of the sample is slightly sticky after 24 hours. The reason may be that the additive content is relatively small, and the system cannot 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 bulging still occurs in the anti-bulging test. When the polyalkoxy-terminated 107 glue of the embodiment of the present invention is used as the base polymer, the curing speed of the prepared dealcoholized silicone sealant is greatly improved, the surface drying time is significantly shortened, and the curing depth is significantly improved, which is comparable to or even exceeds the dealcoholized oxime silicone sealant; moreover, the sample is completely detackified after 24 hours of curing, and the mechanical strength of the sample is significantly improved after sufficient curing; the anti-bulking effect is good, and the yellowing resistance and extrusion performance are also significantly improved, which is more conducive to improving construction efficiency. Since the system content of additives is relatively low, the glue sample is fully cross-linked, the total volatile organic compound content is significantly reduced, and it is more environmentally friendly.

[0114] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A dealcoholized silicone sealant, characterized in that: The dealcoholized silicone sealant comprises the following components in parts by weight: The polyalkoxy-terminated 107 glue is obtained by first subjecting 107 glue to an aminosilane-terminated modification reaction to obtain aminosilane-terminated modified 107 glue, and then subjecting the aminosilane-terminated modified 107 glue to a polyalkoxy-terminated reaction with epoxysilane.

2. The dealcoholized silicone sealant according to claim 1, characterized in that: The aminosilane is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane; and / or, The epoxysilane is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

3. The dealcoholized silicone sealant according to claim 1, characterized in that: The weight ratio of the 107 glue, aminosilane and epoxysilane is 100:2-10:2-10; preferably, the weight ratio of the 107 glue, aminosilane and epoxysilane is 100:3-5:3-5.

4. The dealcoholized silicone sealant according to any one of claims 1 to 3, characterized in that: The preparation method of the polyalkoxy-terminated 107 glue comprises the following steps: The dehydrated 107 glue and aminosilane are subjected to an aminosilane end-capping modification reaction under the action of a catalyst to obtain the aminosilane end-capping modified 107 glue; The obtained aminosilane-terminated modified 107 glue is subjected to a polyalkoxy-terminated reaction with epoxysilane to obtain the polyalkoxy-terminated 107 glue.

5. The dealcoholized silicone sealant according to claim 4, characterized in that: The aminosilane end-capping modification reaction is carried out in an acid catalyst and a base catalyst in sequence; 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, The acid catalyst is at least one of hydrochloric acid, sulfuric acid, phosphoric acid and acetic acid; more preferably, the acid catalyst is acetic acid; and / or, The alkaline catalyst is at least one of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, tert-butylamine and isopropylamine.

6. The dealcoholized silicone sealant according to claim 5, characterized in that: The catalytic reaction of adding the acid catalyst is stirred in an inert gas environment for 60min to 120min, and the reaction temperature is 60°C to 90°C; and / or, the catalytic reaction of adding the base catalyst is stirred in an inert gas environment for 60min to 120min, and the reaction temperature is 60°C to 90°C.

7. The dealcoholized silicone sealant according to claim 4, characterized in that: The dehydration treatment of the 107 glue comprises the following steps: dehydration for 60 min to 120 min at 90° C. to 110° C. and -0.080 MPa to -0.099 MPa; and / or, Before the aminosilane-terminated modified 107 glue reacts with epoxy silane, the method further comprises treating the obtained aminosilane-terminated modified 107 glue at a temperature of 130° C. to 160° C. and a vacuum degree of -0.090 MPa to -0.099 MPa for 60 min to 120 min.

8. The dealcoholized silicone sealant according to claim 4, characterized in that: The polyalkoxy-terminated reaction comprises the following steps: in an inert gas environment, stirring the obtained aminosilane-terminated modified 107 glue and epoxysilane at a temperature of 60° C. to 90° C. for 60 min to 180 min to obtain the polyalkoxy-terminated 107 glue.

9. The dealcoholized silicone sealant according to any one of claims 1 to 3, characterized in that: The 107 glue is α, ω-dihydroxy polydimethylsiloxane, and the viscosity at 25° C. is 10 Pa·s to 100 Pa·s; and / or, The aminosilane is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane; and / or, The epoxysilane is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; and / or, The viscosity of the dimethyl silicone oil at 25° C. is 0.1 Pa·s to 0.5 Pa·s; and / or, The reinforcing filler is at least one of nano-active calcium carbonate, heavy calcium carbonate, silicon powder and diatomaceous earth; and / or, The crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane and phenyltrimethoxysilane; and / or, The coupling agent is at least one of γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane; and / or, The catalyst is a titanate catalyst; preferably, the catalyst is at least one of tetraisopropyl titanate, tetrabutyl titanate, diisopropyl di(ethyl acetoacetate) titanate, dibutoxy di(ethyl acetoacetate) titanate, and diisobutyl di(ethyl acetoacetate) titanate.

10. A method for preparing the dealcoholized silicone sealant according to any one of claims 1 to 9, characterized in that: The steps include: Dehydrate and blend the polyalkoxy-terminated 107 glue, dimethyl silicone oil and reinforcing filler at a temperature of 80°C to 130°C under vacuum conditions for 60min to 180min; After cooling to 40° C. to 50° C., a crosslinking agent, a coupling agent and a catalyst are added, and the mixture is stirred and reacted for 40 min to 120 min under vacuum conditions to obtain the dealcoholized silicone sealant.

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