Dealcoholization type silicone sealant capable of being rapidly cured and having formaldehyde removal and warning functions and preparation method of dealcoholization type silicone sealant

Abstract

The invention relates to a dealcoholized silicone sealant capable of being rapidly cured and having formaldehyde removal and warning functions and a preparation method thereof. The dealcoholized silicone sealant is prepared from the following raw materials in parts by weight: 100 parts of polydimethylsiloxane; 15 to 50 parts of dimethyl silicone oil; 80 to 200 parts of an inorganic filler; 1-3 parts of a cross-linking agent; 10 to 30 parts of 4-amino-N-[3-(trialkoxysilyl) propyl] benzamide; 1.5 to 6 parts of a titanate catalyst; the structural formula of the 4-amino-N-[3-(trialkoxysilyl) propyl] benzamide is shown in the specification. The dealcoholized silicone sealant disclosed by the invention simultaneously realizes multiple functions of rapid curing, mechanical enhancement, formaldehyde removal and formaldehyde warning.

Description

Technical Field

[0001] This invention belongs to the field of sealant technology, and relates to de-alcoholized silicone sealant, specifically to a de-alcoholized silicone sealant that can cure quickly and has both formaldehyde removal and warning functions, and its preparation method. Background Technology

[0002] In the field of interior decoration and renovation, formaldehyde pollution remains a core concern for consumers. Furniture, especially cabinets and cupboards made from plywood, particleboard, and other wood products, continuously releases formaldehyde during use. Long-term exposure to this environment poses a significant threat to human health. Because formaldehyde is a colorless and odorless compound, ordinary consumers lack professional monitoring equipment and cannot detect its release in daily life. Often, by the time symptoms appear, the damage is irreversible, causing irreparable harm to health.

[0003] Silicone sealants, with their excellent weather resistance, high and low temperature resistance, bonding strength, and elastic recovery, are widely used in various joint sealing scenarios in interior decoration and renovation, playing a crucial role in waterproofing, dustproofing, and sealing. Among them, de-alcoholized silicone sealants, due to their outstanding advantages of being green and environmentally friendly, meet the environmental protection requirements of interior decoration, and their market application demand is continuously rising.

[0004] However, existing de-alcoholized silicone sealants generally suffer from slow curing speeds, making them unsuitable for efficient application and a recognized problem in the industry. Furthermore, current de-alcoholized silicone sealants only provide basic sealing, lacking both the environmental benefits of actively absorbing formaldehyde and a visual warning mechanism to indicate formaldehyde release, thus failing to address the need for indoor formaldehyde pollution control. Developing a de-alcoholized silicone sealant that combines rapid curing, formaldehyde adsorption and removal, and color-coded formaldehyde release warnings would not only overcome the industry's pain point of low curing efficiency but also provide consumers with visible formaldehyde safety assurance, effectively reducing the harm of formaldehyde to the human body. Unfortunately, to date, no such multi-functional, integrated de-alcoholized silicone sealant product has appeared on the market, highlighting the urgent need for its development within the industry. Summary of the Invention

[0005] Based on this, the purpose of this invention is to provide a de-alcoholized silicone sealant that combines rapid curing, formaldehyde adsorption and removal, and formaldehyde release color warning functions.

[0006] The technical solutions for achieving the above objectives include the following.

[0007] In a first aspect, the present invention provides a dealcoholized silicone sealant, the raw material composition of which, by weight, comprises:

[0008] 100 parts of polydimethylsiloxane;

[0009] 15-50 parts of dimethyl silicone oil;

[0010] Inorganic filler 80-200 parts;

[0011] 1-3 parts of crosslinking agent;

[0012] 8-40 parts of 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide;

[0013] Titanate catalyst 1.5–6 parts;

[0014] The polydimethylsiloxane is selected from at least one of the following: polydimethylsiloxane terminally capped with methyldimethoxysilane, polydimethylsiloxane terminally capped with methyldiethoxysilane, polydimethylsiloxane terminally capped with vinyldimethoxysilane, polydimethylsiloxane terminally capped with vinyldiethoxysilane, polydimethylsiloxane terminally capped with trimethoxysilane, and polydimethylsiloxane terminally capped with triethoxysilane.

[0015] The structural formula of the 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide is:

[0016]

[0017] R1, R2 and R3 are each independently selected from C1-C3 alkyl groups.

[0018] Secondly, the present invention provides a method for preparing the de-alcoholized silicone sealant of the present invention, comprising the following steps: dehydrating and blending the alkyl polydimethylsiloxane, dimethyl silicone oil, and inorganic filler under vacuum conditions at a temperature of 90℃~120℃, cooling to 40℃~60℃, adding the crosslinking agent, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide and titanate catalyst, and mixing and reacting under vacuum conditions to obtain the de-alcoholized silicone sealant.

[0019] The present invention has the following beneficial effects:

[0020] This invention utilizes 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide in combination with alkyl polydimethylsiloxane, dimethyl silicone oil, filler, crosslinking agent, and titanate catalyst to prepare a rapidly curing, formaldehyde-removing, and warning-type silicone sealant. When applied to seal joints in interior decoration, the primary amino group in 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide undergoes a Schiff base reaction with formaldehyde, which enhances the deep curing rate and mechanical strength of the sealant while achieving efficient formaldehyde removal. Furthermore, the benzene ring and C=N double bond in the product form a large π-conjugated structure, which allows the sealant to turn orange-yellow after absorbing visible light, serving as a formaldehyde release warning. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0022] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0023] 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.

[0024] Furthermore, as used herein, the term "or" is an inclusive "or" sign and is equivalent to the term "and / or" unless the context clearly specifies otherwise. The term "based on" is not exclusive and allows for basing on other factors not described unless the context clearly specifies otherwise. Additionally, throughout the specification, the meanings of "an," "a," and "the" include plural indicators. The meaning of "in" includes both "in" and "on."

[0025] Traditional de-alcoholized silicone sealants have a slow deep curing speed; existing de-alcoholized silicone sealants can only achieve joint sealing in indoor decoration scenarios, lacking formaldehyde removal efficacy, failing to address the pain point of formaldehyde pollution after indoor decoration, and are not environmentally friendly enough; furthermore, they lack a direct warning mechanism for formaldehyde release, making it difficult for users to easily determine the presence of formaldehyde and the progress of the reaction, resulting in poor safety and user experience; in other words, traditional de-alcoholized silicone sealants cannot simultaneously achieve multiple functions of "rapid curing, mechanical enhancement, formaldehyde removal, and formaldehyde warning" in a single sealant, and there is a technical bottleneck in balancing single function and performance.

[0026] Based on this, the purpose of this invention is to provide a de-alcoholized silicone sealant with excellent mechanical properties that can cure quickly and has both formaldehyde removal and warning functions. This sealant not only meets the basic requirements for sealing joints in interior decoration and renovation, but also achieves two core objectives: first, to improve the deep curing rate and mechanical strength of the sealant and optimize its performance; second, to efficiently remove formaldehyde from the air during the sealing process and to visually warn of formaldehyde release through color changes, thus balancing environmental protection and safety, and solving the problem of the single function of existing de-alcoholized silicone sealants.

[0027] Based on the aforementioned technical problems, the inventors of this invention, after extensive experimental research, discovered that adding 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide, the product obtained by reacting 3-aminopropyltrialkoxysilane (e.g., 3-aminopropyltrimethoxysilane or 3-propyltriethoxysilane) with p-aminobenzoic acid, to a dealcoholized silicone sealant can significantly improve the deep curing rate and mechanical strength of the sealant. Furthermore, the primary amino group in 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide can undergo a Schiff base reaction with formaldehyde, which can further enhance the deep curing rate and mechanical strength of the sealant and achieve efficient formaldehyde removal; moreover, the benzene ring and C=N double bond in the product form a large π-conjugated structure, which can cause the sealant to turn orange-yellow after absorbing visible light, serving as a formaldehyde release warning. This approach cleverly and simply overcomes the technical bottleneck of traditional de-alcoholized silicone sealants, which struggle to simultaneously achieve multiple functions such as "rapid curing, mechanical enhancement, formaldehyde removal, and formaldehyde warning."

[0028] Based on this, some embodiments of the present invention relate to a de-alcoholized silicone sealant, the raw material composition of which, by weight, includes:

[0029] 100 parts of polydimethylsiloxane;

[0030] 15-50 parts of dimethyl silicone oil;

[0031] Inorganic filler 80-200 parts;

[0032] 1-3 parts of crosslinking agent;

[0033] 8-40 parts of 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide;

[0034] Titanate catalyst 1.5–6 parts;

[0035] The polydimethylsiloxane is selected from at least one of the following: polydimethylsiloxane terminally capped with methyldimethoxysilane, polydimethylsiloxane terminally capped with methyldiethoxysilane, polydimethylsiloxane terminally capped with vinyldimethoxysilane, polydimethylsiloxane terminally capped with vinyldiethoxysilane, polydimethylsiloxane terminally capped with trimethoxysilane, and polydimethylsiloxane terminally capped with triethoxysilane.

[0036] The structural formula of the 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide is:

[0037]

[0038] R1, R2 and R3 are each independently selected from C1-C3 alkyl groups.

[0039] In some embodiments, the raw material composition, by weight, includes:

[0040] 100 parts of polydimethylsiloxane;

[0041] 30-45 parts of dimethyl silicone oil;

[0042] 100-150 parts of inorganic filler;

[0043] 1-3 parts of crosslinking agent;

[0044] 10-30 parts of 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide;

[0045] 3 to 5 parts of titanate catalyst.

[0046] In some embodiments, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide is more preferably 15-30 parts, for example 15 parts, 20 parts, 25 parts or 30 parts.

[0047] In some embodiments, R1, R2, and R3 are all methyl or all ethyl.

[0048] In some embodiments, the viscosity of the polydimethylsiloxane at 25°C is 10,000 mPa·s to 80,000 mPa·s, preferably 20,000 mPa·s to 50,000 mPa·s.

[0049] In some embodiments, the dimethyl silicone oil has a viscosity of 80 mPa·s to 500 mPa·s at 25°C, preferably 100 mPa·s to 350 mPa·s.

[0050] In some embodiments, the inorganic filler is at least one of nano-activated calcium carbonate, light calcium carbonate, and heavy calcium carbonate.

[0051] In some embodiments, the crosslinking agent is at least one selected from methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, and vinyltrimethoxysilane.

[0052] In some embodiments, the titanate catalyst is selected from at least one of tetraisopropyl titanate, tetrabutyl titanate, diisopropyl di(ethyl acetoacetate) titanate, dibutoxybis(ethyl acetoacetate) titanate, and di(ethyl acetoacetate) diisobutyl titanate.

[0053] Some embodiments of the present invention relate to a method for preparing the de-alcoholized silicone sealant of the present invention, comprising the following steps: dehydrating and blending the alkyl polydimethylsiloxane, dimethyl silicone oil, and inorganic filler under vacuum conditions at a temperature of 90°C to 120°C, cooling to 40°C to 60°C, adding the crosslinking agent, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide, and titanate catalyst, and mixing and reacting under vacuum conditions to obtain the de-alcoholized silicone sealant.

[0054] In some embodiments, the preparation method of the de-alcoholized silicone sealant includes the following steps: dehydrating and blending the alkyl polydimethylsiloxane, dimethyl silicone oil, and inorganic filler at a temperature of 90℃~110℃ and a vacuum degree of -0.085MPa~-0.099MPa for 60min~180min, cooling to 45℃~55℃, adding the crosslinking agent, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide, and titanate catalyst, and mixing and reacting at a vacuum degree of -0.090~-0.099MPa and a stirring speed of 200rpm~600rpm for 50min~90min to obtain the de-alcoholized silicone sealant.

[0055] The present invention will be further described in detail below with reference to specific embodiments.

[0056] In the following examples, unless otherwise specified, "parts" in the amount of raw materials refers to parts by weight.

[0057] The viscosity in the following examples refers to the viscosity tested at 25°C.

[0058] Example 1

[0059] Under nitrogen atmosphere, 100 parts of p-aminobenzoic acid were dissolved in 87 parts of thionyl chloride, and the mixture was refluxed at 85°C for 6 hours. The mixture was then purified by vacuum distillation at -0.099 MPa to obtain the intermediate p-aminobenzoyl chloride. Next, under nitrogen atmosphere, p-aminobenzoyl chloride was dissolved in anhydrous toluene, and 131 parts of 3-aminopropyltrimethoxysilane were added. The mixture was stirred at room temperature for 48 hours until the nitrogen flow was stopped, the temperature was raised to 100°C, and the pressure was evacuated to -0.099 MPa to remove toluene and HCl, yielding 4-amino-N-[3-(trimethoxysilyl)propyl]benzamide.

[0060] The reaction formula is as follows:

[0061] ①H2N-C6H4-COOH+SOCl2→H2N-C6H4-COCl+SO2↑+HCl ↑

[0062] ②H2N-C6H4-COCl + H2N-(CH2)3-Si(OCH3)3 →

[0063] H2N-C6H4-C(O)-HN-(CH2)3-Si(OCH3)3+ HCl ↑

[0064] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane (i.e., the product of the hydroxyl group at the end of 107 glue reacting with methyltrimethoxysilane to remove one methanol molecule), 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at a temperature of 110℃ and a vacuum of -0.090 MPa. After being fully cooled to 50℃, 2 parts of methyltrimethoxysilane, 20 parts of 4-amino-N-[3-(trimethoxysilyl)propyl]benzamide, and 3 parts of diisopropyl di(ethyl acetoacetate)titanate were added and mixed and reacted for 60 min at a vacuum of -0.098 MPa and a stirring speed of 500 rpm to obtain a de-alcoholized silicone sealant composition that can cure quickly and has both formaldehyde removal and warning functions.

[0065] Example 2

[0066] Under nitrogen atmosphere, 100 parts of p-aminobenzoic acid were dissolved in 87 parts of thionyl chloride, and the mixture was refluxed at 85°C for 6 hours. The mixture was then purified by vacuum distillation at -0.099 MPa to obtain the intermediate p-aminobenzoyl chloride. Next, under nitrogen atmosphere, p-aminobenzoyl chloride was dissolved in anhydrous toluene, and 162 parts of 3-aminopropyltriethoxysilane were added. The mixture was stirred at room temperature for 48 hours until the nitrogen flow was stopped, the temperature was raised to 100°C, and the pressure was evacuated to -0.099 MPa to remove toluene and HCl, yielding 4-amino-N-[3-(triethoxysilyl)propyl]benzamide.

[0067] The reaction formula is as follows:

[0068] ①H2N-C6H4-COOH+SOCl2→H2N-C6H4-COCl+SO2↑+HCl ↑

[0069] ②H2N-C6H4-COCl + H2N-(CH2)3-Si(OCH2CH3)3 →

[0070] H2N-C6H4-C(O)-HN-(CH2)3-Si(OCH2CH3)3+ HCl ↑

[0071] 100 parts of methyl-diethoxysilane-terminated polydimethylsiloxane (i.e., the product of the hydroxyl group at the end of 107 glue reacting with methyltriethoxysilane to remove one ethanol molecule), 45 parts of dimethyl silicone oil with a viscosity of 100 mPa·s, and 100 parts of light calcium carbonate were dehydrated and blended for 180 min at a temperature of 90 °C and a vacuum of -0.099 MPa. After being fully cooled to 45 °C, 1 part of methyltriethoxysilane, 15 parts of 4-amino-N-[3-(triethoxysilyl)propyl]benzamide, and 5 parts of dibutoxybis(ethyl acetoacetate) titanate were added and mixed and reacted for 90 min at a vacuum of -0.090 MPa and a stirring speed of 300 rpm to obtain a de-alcoholized silicone sealant composition that can cure quickly and has both formaldehyde removal and warning functions.

[0072] Example 3

[0073] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at 110 °C and -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane, 10 parts of 4-amino-N-[3-(trimethoxysilyl)propyl]benzamide, and 3 parts of diisopropyl di(ethyl acetoacetate)titanate were added. The mixture was then stirred at -0.098 MPa vacuum and 500 rpm for 60 min to obtain a de-alcoholized silicone sealant composition that can cure quickly and has both formaldehyde removal and warning functions.

[0074] Example 4

[0075] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at 110 °C and -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane, 30 parts of 4-amino-N-[3-(trimethoxysilyl)propyl]benzamide, and 3 parts of di(ethyl acetoacetate)titanate diisopropyl ester were added. The mixture was then stirred for 60 min at -0.098 MPa vacuum and 500 rpm to obtain a de-alcoholized silicone sealant composition that can cure quickly and has both formaldehyde removal and warning functions.

[0076] Comparative Example 1

[0077] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at a temperature of 110 °C and a vacuum of -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane and 3 parts of diisopropyl di(ethyl acetoacetate) titanate were added, and the mixture was stirred at a vacuum of -0.098 MPa and a stirring speed of 500 rpm for 60 min to obtain a de-alcoholized silicone sealant composition.

[0078] Comparative Example 2

[0079] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at 110 °C and -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane, 20 parts of 3-aminopropyltrimethoxysilane, and 3 parts of diisopropyl di(ethyl acetoacetate) titanate were added. The mixture was then stirred at -0.098 MPa and 500 rpm for 60 min to obtain a de-alcoholized silicone sealant composition.

[0080] Comparative Example 3

[0081] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at a temperature of 110 °C and a vacuum of -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane, 20 parts of p-aminobenzoic acid, and 3 parts of diisopropyl di(ethyl acetoacetate) titanate were added and mixed and reacted for 60 min at a vacuum of -0.098 MPa and a stirring speed of 500 rpm to obtain a dealcoholized silicone sealant composition.

[0082] Comparative Example 4

[0083] 100 parts of methyldimethoxysilane-terminated polydimethylsiloxane with a viscosity of 20000 mPa·s, 30 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 150 parts of nano-activated calcium carbonate were dehydrated and blended for 120 min at 110 °C and -0.090 MPa. After being fully cooled to 50 °C, 2 parts of methyltrimethoxysilane, 8.7 parts of p-aminobenzoic acid, 11.3 parts of 3-aminopropyltrimethoxysilane, and 3 parts of diisopropyl di(ethyl acetoacetate) titanate were added. The mixture was then stirred at -0.098 MPa and 500 rpm for 60 min to obtain a de-alcoholized silicone sealant composition.

[0084] The alcohol-free silicone sealant samples prepared in Examples 1-4 and Comparative Examples 1-4 were tested for curing depth, mechanical properties, formaldehyde removal effect, and color change in the following manner.

[0085] Multiple 50cm x 50cm planks were cut from the same piece of particleboard and made into several 50cm x 50cm x 50cm wooden boxes that could be flipped open to simulate a wardrobe.

[0086] 1. Curing Depth (mm) Test: Take two square glass slides with a side length of 50mm. After thoroughly cleaning and drying the surfaces with ethanol, apply a wad of adhesive to one of the glass slides and press the other glass slide onto the wad, ensuring the two glass slides are parallel and the distance between them is controlled at 10mm. Use a scraper to remove the excess adhesive around the edges of the two parallel glass slides, ensuring the adhesive surface is smooth. After curing the specimen for a period of time, cut the adhesive along the parallel surfaces. After removing the uncured adhesive, measure the thickness of the cured adhesive around the edges of the specimen and take the average value, which is the curing depth value. When testing the curing depth, prepare two sets of specimens for each scheme, one specimen in each set. One set of specimens is placed in a constant temperature and humidity chamber under standard conditions of 23℃ and 50%RH; the other set of specimens is placed in the same wooden box under standard conditions for curing times of 24h, 48h, and 72h.

[0087] 2. Mechanical property testing: Tensile strength was tested according to GB / T 528-2009, using type 1 dumbbell-shaped specimens. Two sets of specimens were prepared for each scheme, with three specimens in each set. One set of specimens was cured in a constant temperature and humidity chamber at 23℃ and 50%RH for 7 days; the other set of specimens was placed in the same wooden box, which was then cured under standard conditions for 7 days.

[0088] 3. Formaldehyde content test: Extrude the de-alcoholized silicone sealant into a mold frame with dimensions of 150×60×5mm (length×width×height). After smoothing the surface, obtain the test specimen. Immediately place each specimen in a separate wooden box as described above. Cure all wooden boxes at 23℃ and 50%RH for 30 days. After curing, test the formaldehyde concentration in the wooden boxes according to GB18584-2001 standard.

[0089] 4. Degree of color change: After the specimens were cured in a wooden box for 30 days, they were placed in the sun for 1 day and the color change of the specimens was observed with the naked eye.

[0090] Table 1. Curing depth, mechanical properties, formaldehyde removal effect, and discoloration of de-alcoholized silicone sealant samples.

[0091]

[0092]

[0093] As shown in Table 1, examples 1-4 and Comparative Example 1 demonstrate that 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide can improve the curing speed and mechanical strength of the de-alcoholized silicone sealant. The de-alcoholized silicone sealant with added 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide exhibits faster curing speed in wooden boxes and also removes formaldehyde. Examples 1 and Comparative Example 3 show that while direct addition of p-aminobenzoic acid can also remove formaldehyde, it significantly reduces the mechanical strength of the sealant and does not improve the curing speed. However, after modification with aminosilane, p-aminobenzoic acid significantly improves the curing speed and mechanical strength of the de-alcoholized silicone sealant. As shown in Example 1 and Comparative Examples 1-4, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide can endow the de-alcoholized silicone sealant with the ability to remove formaldehyde. After reacting with formaldehyde, the benzene ring in the 4-(methyleneamino)-N-[3-(trialkoxysilyl)propyl]benzamide structure forms a large π conjugated structure with the C=N double bond, which can absorb visible light and appear orange-yellow, causing the sealant to turn yellow obviously, thus intuitively realizing the visual warning function of formaldehyde release.

[0094] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A de-alcoholized silicone sealant, characterized in that, The raw material composition, by weight, includes: 100 parts of polydimethylsiloxane; 15-50 parts of dimethyl silicone oil; Inorganic filler 80-200 parts; 1-3 parts of crosslinking agent; 8-40 parts of 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide; Titanate catalyst 1.5–6 parts; The polydimethylsiloxane is selected from at least one of the following: polydimethylsiloxane terminally capped with methyldimethoxysilane, polydimethylsiloxane terminally capped with methyldiethoxysilane, polydimethylsiloxane terminally capped with vinyldimethoxysilane, polydimethylsiloxane terminally capped with vinyldiethoxysilane, polydimethylsiloxane terminally capped with trimethoxysilane, and polydimethylsiloxane terminally capped with triethoxysilane. The structural formula of the 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide is: R1, R2 and R3 are each independently selected from C1-C3 alkyl groups.

2. The de-alcoholized silicone sealant according to claim 1, characterized in that, The raw material composition, by weight, includes: 100 parts of polydimethylsiloxane; 30-45 parts of dimethyl silicone oil; 100-150 parts of inorganic filler; 1-3 parts of crosslinking agent; 10-30 parts of 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide; 3-5 parts of titanate catalyst; 4-Amino-N-[3-(trialkoxysilyl)propyl]benzamide is more preferably 15-30 parts.

3. The de-alcoholized silicone sealant according to claim 1, characterized in that, R1, R2 and R3 are all methyl, or all ethyl.

4. The de-alcoholized silicone sealant according to claim 1, characterized in that, The viscosity of the polydimethylsiloxane at 25°C is 10,000 mPa·s to 80,000 mPa·s, preferably 20,000 mPa·s to 50,000 mPa·s.

5. The de-alcoholized silicone sealant according to claim 1, characterized in that, The dimethyl silicone oil has a viscosity of 80 mPa·s to 500 mPa·s at 25°C, preferably 100 mPa·s to 350 mPa·s.

6. The de-alcoholized silicone sealant according to claim 1, characterized in that, The inorganic filler is at least one of nano-activated calcium carbonate, light calcium carbonate, and heavy calcium carbonate.

7. The de-alcoholized silicone sealant according to claim 1, characterized in that, The crosslinking agent is at least one selected from methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, and vinyltrimethoxysilane.

8. The de-alcoholized silicone sealant according to claim 1, characterized in that, The titanate catalyst is selected from at least one of tetraisopropyl titanate, tetrabutyl titanate, diisopropyl titanate (ethyl acetoacetate), dibutoxybis(ethyl acetoacetate) titanate, and diisobutyl titanate (ethyl acetoacetate).

9. A method for preparing a dealcohol-type silicone sealant according to any one of claims 1-8, characterized in that, The process includes the following steps: dehydrating and blending the alkyl polydimethylsiloxane, dimethyl silicone oil, and inorganic filler under vacuum conditions at a temperature of 90℃~120℃, cooling to 40℃~60℃, adding the crosslinking agent, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide, and titanate catalyst, and mixing and reacting under vacuum conditions to obtain the de-alcoholized silicone sealant.

10. The method for preparing the dealcoholized silicone sealant according to claim 9, characterized in that, The process includes the following steps: Dehydrating and blending the alkyl polydimethylsiloxane, dimethyl silicone oil, and inorganic filler at a temperature of 90℃~110℃ and a vacuum of -0.085MPa~-0.099MPa for 60min~180min, cooling to 45℃~55℃, adding the crosslinking agent, 4-amino-N-[3-(trialkoxysilyl)propyl]benzamide, and titanate catalyst, and mixing and reacting at a vacuum of -0.090~-0.099MPa and a stirring speed of 200rpm~600rpm for 50min~90min to obtain the de-alcoholized silicone sealant.

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