Silane modified polyether material capable of accelerating deep moisture curing and preparation method of silane modified polyether material

Abstract

The invention discloses a silane modified polyether material capable of accelerating deep moisture curing and a preparation method of the silane modified polyether material, and relates to the technical field of sealants. Comprising the following steps: S1, mixing polyether polyol and diisocyanate, and carrying out primary stirring treatment to obtain an isocyanate-terminated prepolymer; s2: (1) stirring aminopropyltrimethoxysilane, methanol and hydroxyethyl acrylate, heating, and continuing stirring to obtain special silane; (2) in an inert gas atmosphere, mixing the isocyanate-terminated prepolymer and special silane, and performing secondary stirring treatment to obtain special silane-terminated polyether resin; and S3, in an inert gas atmosphere, mixing the special silane-terminated polyether resin and special high-activity silane, and stirring for three times to obtain the accelerated deep moisture curing silane modified polyether material. The material has good storage performance, can accelerate deep curing in cold weather, and has excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of sealant technology, specifically to an accelerated deep-curing silane-modified polyether material and its preparation method. Background Technology

[0002] Silane-modified polyether resin is a technological product that uses silanes containing terminal siloxanes to modify high molecular weight polyether polyols or allyl polyethers. The advantages of this resin are that it releases small-molecule alcohols during curing, which are colorless, odorless, safe, and environmentally friendly. As a silane-modified polyether material, this resin combines the advantages of both organosilicon and polyurethane, exhibiting rapid curing and excellent water resistance, weather resistance, and adhesive properties.

[0003] The main component of silane-modified polyether sealants is silane-modified polyether resin, a relatively high-end product on the market. Major raw material suppliers are primarily foreign companies, including Wacker Chemie, Covestro, and Evonik. The use of silane-modified polyether resin can solve many of the drawbacks of silicone sealants used in various industries, including the production of irritating odors after curing and the inability to paint the surface. Furthermore, compared to polyurethane sealants, silane-modified polyether sealants do not contain free isocyanates and organic solvents, and possess a more weather-resistant silicone structure, resulting in superior weather resistance.

[0004] Silane-modified polyether sealant combines the advantages of silicone sealant and polyurethane sealant to some extent, while avoiding some of their disadvantages. It has been widely used in various industries, enriching the development prospects of high-end sealants.

[0005] However, the silanes used in conventional silane-modified polyether resins are mostly aminopropyltrimethoxysilanes, which are cured using organotin catalysts and under the action of water vapor. They have high curing efficiency at room temperature, but in cold regions, there are problems such as insufficient surface curing and slow deep curing, which seriously affects the performance of the sealant.

[0006] In summary, solving the above problems and preparing a silane-modified polyether material for accelerated deep moisture curing is of great significance. Summary of the Invention

[0007] The purpose of this invention is to provide an accelerated deep-curing silane-modified polyether material and its preparation method, so as to solve the problems mentioned in the background art.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing accelerated deep moisture-curing silane-modified polyether materials includes the following steps: S1: Polyether polyol and diisocyanate are mixed and stirred once to obtain isocyanate-terminated prepolymer; S2: (1) Mix aminopropyltrimethoxysilane, methanol and hydroxyethyl acrylate and stir at 20~30℃ for 1~1.5h, raise the temperature to 60~65℃ and stir for 1~1.5h, remove methanol by rotary evaporation to obtain special silane; (2) Under an inert gas atmosphere, mix isocyanate-terminated prepolymer and special silane and stir twice to obtain special silane-terminated polyether resin; S3: Under an inert gas atmosphere, a special silane-terminated polyether resin and a special highly active silane are mixed and stirred three times to obtain an accelerated deep-curing silane-modified polyether material.

[0009] Preferably, the special silane comprises the following structure: .

[0010] Preferably, the mass ratio of aminopropyltrimethoxysilane to hydroxyethyl acrylate is 100:65~75.

[0011] Preferably, the amount of the special silane added accounts for 3 to 15 wt% of the isocyanate-terminated prepolymer.

[0012] Preferably, the special highly active silane includes N-[[(dimethoxy)(methyl)silyl]methyl]carbamate.

[0013] Preferably, the amount of the special highly active silane added accounts for 0.1 to 1 wt% of the isocyanate-terminated prepolymer.

[0014] Preferably, the polyether polyol has a functionality of 2 and a number-average molecular weight of 2000-8000; The diisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0015] Preferably, the amount of diisocyanate added accounts for 4 to 15 wt% of the polyether polyol.

[0016] Preferably, during the first stirring process, the temperature is 40~60℃ and the time is 2~6h; During the secondary stirring process, the temperature is 40~60℃ and the time is 1~2h; During the three stirring processes, the temperature is 20~30℃ and the time is 0.5~1h.

[0017] Preferably, when the accelerated deep moisture-curing silane-modified polyether material is applied, 0.1~1 wt% of its mass of catalyst is introduced for moisture curing to obtain the product; wherein, the catalyst is preferably a T12-KH792 composite catalyst, and after one week of air moisture curing, the product modulus reaches 0.5~1 MPa.

[0018] The T12-KH792 composite catalyst system includes dibutyltin dilaurate (T12) and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (KH792).

[0019] All of the above-mentioned reaction processes are generally carried out in a reaction vessel commonly used in the field. The reaction vessel is generally equipped with a stirrer, a thermocouple thermometer, a vacuum elbow and a nitrogen port. The vacuum elbow needs to be connected to a vacuum pump or other vacuum equipment, and the nitrogen port needs to be connected to a nitrogen source.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present application selects a polyether polyol of a specific molecular weight to react with diisocyanate to obtain an isocyanate-terminated prepolymer, and then reacts the isocyanate-terminated prepolymer with a specific special silane to obtain a special silane-terminated polyether resin, and further adds a specific proportion of special high-activity silane to compound it. The resulting silane-modified polyether material significantly improves the speed and depth of deep wet curing and has excellent mechanical properties.

[0021] Among them, polyether diols with a molecular weight of 2000-8000 are selected as the matrix material, which have moderate chain length and reactivity, which is conducive to maintaining a certain toughness of the material after curing. Isocyanate is used as a connecting unit, which can effectively promote the uniformity of molecular weight distribution of isocyanate-terminated prepolymer, thereby adjusting the mechanical properties and curing depth of the final material. The special silane prepared by introducing aminopropyltrimethoxysilane and hydroxyethyl acrylate through Michael addition reaction has controllable reactivity and steric hindrance effect. Compared with the direct use of aminopropyltrimethoxysilane for end capping, the viscosity is controllable and the storage stability is improved. It solves the problem that aminopropyltrimethoxysilane end capping is prone to viscosity runaway. This is because the introduction of acrylate structure effectively inhibits the premature self-condensation reaction of silane groups and ensures the stability of the system.

[0022] This application further incorporates a highly reactive specialty silane, N-[[(dimethoxy)(methyl)silane]methyl]carbamate, for compounding. This is because its carbamate groups and siloxane groups can synergistically react with the previously introduced specialty silane, accelerating the rapid reaction of the siloxane with water molecules to generate silanols, which then form a hydrogen bond network with the internal silane groups. This accelerates deep moisture penetration and curing reactions, acting as a synergistic catalytic agent. However, the proportion of this silane introduced needs to be limited. Excessive amounts can lead to excessively rapid system reactions, shortened shelf life, and potential internal stress due to localized over-crosslinking, negatively impacting mechanical properties. Simultaneously, the aforementioned specialty silane reacting with the isocyanate needs to be partially in excess. Besides ensuring complete reaction of the isocyanate, it can also act as a hydrolysis crosslinking point, participating in the moisture curing process and enhancing the integrity of the final material's network structure.

[0023] The accelerated deep-curing silane-modified polyether material prepared in this application is free of free isocyanate and can accelerate deep curing in cold weather. After curing, the resin releases small-molecule alcohols, resulting in low VOC emissions and environmental friendliness. Furthermore, its applications include, but are not limited to, sealant products, and it can be used for bonding and sealing structural components. It possesses high modulus, high strength, and a certain elongation at break, making it suitable for bonding and sealing applications. Attached Figure Description

[0024] Figure 1 Infrared spectrum of the special silane prepared in this application. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that the following quantities are by weight. There are no special restrictions on the suppliers of any of the raw materials involved in this invention. Exemplary examples include: polyether polyol DL-4000 provided by Shandong Lanxing Dongda Co., Ltd., with a functionality of 2 and a number-average molecular weight of 4000. Toluene diisocyanate (TDI) is preferably TDI produced by Yantai Wanhua; aminopropyltrimethoxysilane CAS number: 13822-56-5; hydroxyethyl acrylate CAS number: 818-61-1; special highly active silane: N-[[(dimethoxy)(methyl)silyl]methyl]carbamate CAS number: 23432-65-7.

[0027] In the following examples, parts refer to parts by weight, and all raw materials mentioned above and others not mentioned are commercially available.

[0028] Pre-preparation: Preparation of special silane: 100 parts of aminopropyltrimethoxysilane and 20 parts of methanol were added to a flask, and 66.7 parts of hydroxyethyl acrylate were added dropwise. The mixture was stirred at 25°C for 1 hour, then heated to 60°C and stirred for 1 hour. After removing the methanol by rotary evaporation, the special silane was obtained.

[0029] Example 1: A silane-modified polyether material for accelerating deep moisture curing, prepared by the following method: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 90g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0030] Example 2: A silane-modified polyether material for accelerated deep moisture curing, prepared by the following method: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 120℃, dehydrate and degas under vacuum for 2 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 5 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 80g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 1 hour to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0031] Example 3: A silane-modified polyether material for accelerated deep moisture curing, prepared by the following method: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 120℃, dehydrate and degas under vacuum for 2 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 5 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 70g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 1 hour to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 5g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0032] Comparative Example 1: Based on Example 1, without the addition of a special highly active silane compound: the remaining processes remain unchanged, specifically including the following steps: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 90g of special silane was added to the isocyanate-based end-capped prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain an accelerated deep-curing silane-modified polyether material.

[0033] Comparative Example 2: Based on Example 1, isocyanate-based prepolymers were end-capped using aminopropyltrimethoxysilane, with the remaining processes unchanged. Specifically, the following steps were included: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 59g of aminopropyltrimethoxysilane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0034] Comparative Example 3: Based on Example 1, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was used to replace aminopropyltrimethoxysilane for the preparation of special silanes, with the remaining processes unchanged. Specifically, the following steps were included: Pre-preparation: Preparation of special silanes: 100 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 20 parts of methanol were added to a flask, and 52.2 parts of hydroxyethyl acrylate were added dropwise. The mixture was stirred at 25°C for 1 hour, then heated to 60°C and stirred for 1 hour. After removing the methanol by rotary evaporation, the special silane was obtained. S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 70g of pre-prepared special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0035] Comparative Example 4: Based on Example 1, the amount of special highly active silane added was increased, while the rest of the process remained unchanged. The specific steps included: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 90g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 20g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0036] Comparative Example 5: Based on Example 1, the amount of special silane used is reduced, while the rest of the process remains unchanged. Specifically, it includes the following steps: S1: Add 1000g of polyether polyol DL-4000 to the reactor, heat to 110℃, dehydrate and degas under vacuum for 3 hours, cool to 45℃, then add 70g of toluene diisocyanate (TDI), stir at 55℃ for 6 hours to obtain isocyanate-terminated prepolymer; wherein, the functionality of polyether polyol DL-4000 is 2 and the number average molecular weight is 4000; S2: Under a nitrogen atmosphere, 30g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0037] Comparative Example 6: Based on Example 1, the molecular weight of the polyether polyol was increased while the rest of the process remained unchanged. Specifically, the following steps were included: S1: 1000g of polyether polyol DL-10000 was added to a reactor, heated to 110℃, and dehydrated and degassed under vacuum for 3 hours. The temperature was then lowered to 45℃, and 32g of toluene diisocyanate (TDI) was added. The mixture was stirred at 55℃ for 6 hours to obtain an isocyanate-terminated prepolymer. The polyether polyol DL-10000 has a functionality of 2 and a number-average molecular weight of 10000. S2: Under a nitrogen atmosphere, 90g of special silane was added to the isocyanate-based prepolymer prepared in step S1, and the mixture was stirred at 55°C for 2 hours to obtain a special silane-terminated polyether resin. S3: Under a nitrogen atmosphere, 10g of special high-activity silane was added to the special silane-terminated polyether resin prepared in step S2 and stirred at 25°C for 1 hour to obtain an accelerated deep-curing silane-modified polyether material.

[0038] Performance Testing: The viscosity of the products prepared in each example and comparative example was tested. The hardness, tensile strength, and curing depth of the gel were measured after one week of air-humidity curing in a composite catalytic system of 0.5 wt% dibutyltin dilaurate and 0.5 wt% N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The experimental data are shown in the table below.

[0039] Depend on Figure 1 It is known that in the special silane prepared in this application, the silane located at 1700~1750 cm⁻¹ -1 A carbonyl (C=O) peak appeared at 1630-1650 cm⁻¹, while the peak was located at 1630-1650 cm⁻¹. -1The double peaks at the 3300–3350 cm⁻¹ of the carbon-carbon double bond (C=C) of hydroxyethyl acrylate disappear, and the double peaks at the 3300–3350 cm⁻¹ are also absent. -1 The singlet at the position of secondary amine (-NH-) indicates the successful synthesis of the special silane of this application.

[0040] As shown in the table above, Comparative Example 1, lacking the synergistic catalysis of the special highly active silane, significantly reduced the curing depth. Comparative Example 2, using aminopropyltrimethoxysilane to end-cap the isocyanate-based prepolymer, resulted in a product approaching a gel state, rendering it unusable. Comparative Example 3, using N-(2-aminoethyl)-3-aminopropyltrimethoxysilane instead of aminopropyltrimethoxysilane to prepare the special silane, was similar to Comparative Example 2, but contained excessive secondary amine groups, leading to unlimited chain extension and a final product approaching a gel state, rendering it unusable. In Comparative Example 4, increasing the amount of special highly active silane further improved the curing depth, but significantly reduced storage stability. In Comparative Example 5, reducing the amount of special silane resulted in incomplete isocyanate end-capping and insufficient curing crosslinking points, leading to a significant decrease in hardness, tensile strength, and curing depth. In Comparative Example 6, increasing the molecular weight of the polyether polyol worsened processing performance, and the prepared material showed a significant decrease in hardness and tensile strength.

[0041] Conclusion: In summary, this application uses polyether polyols of specific molecular weights to react with diisocyanates to obtain isocyanate-terminated prepolymers. Then, the isocyanate-terminated prepolymers are reacted with specific special silanes to obtain special silane-terminated polyether resins. Furthermore, a specific proportion of special highly active silanes is added for compounding. The resulting silane-modified polyether material significantly improves the speed and depth of deep wet curing and has excellent mechanical properties.

[0042] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing silane-modified polyether materials for accelerated deep moisture curing, characterized in that: Includes the following steps: S1: Polyether polyol and diisocyanate are mixed and stirred once to obtain isocyanate-terminated prepolymer; S2: (1) Mix aminopropyltrimethoxysilane, methanol and hydroxyethyl acrylate and stir at 20~30℃ for 1~1.5h, raise the temperature to 60~65℃ and stir for 1~1.5h, remove methanol by rotary evaporation to obtain special silane; (2) Under an inert gas atmosphere, mix isocyanate-terminated prepolymer and special silane and stir twice to obtain special silane-terminated polyether resin; S3: Under an inert gas atmosphere, a special silane-terminated polyether resin and a special highly active silane are mixed and stirred three times to obtain an accelerated deep-curing silane-modified polyether material.

2. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The special silane includes the following structure: 。 3. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The mass ratio of aminopropyltrimethoxysilane to hydroxyethyl acrylate is 100:65~75.

4. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The amount of the special silane added is 3 to 15 wt% of the isocyanate-terminated prepolymer.

5. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The special highly active silane includes N-[[(dimethoxy)(methyl)silyl]methyl]carbamate.

6. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The amount of the special highly active silane added accounts for 0.1~1 wt% of the isocyanate-terminated prepolymer.

7. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The polyether polyol has a functionality of 2 and a number-average molecular weight of 2000~8000; The diisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

8. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: The amount of diisocyanate added is 4-15 wt% of the polyether polyol.

9. The method for preparing an accelerated deep-curing silane-modified polyether material according to claim 1, characterized in that: During the first stirring process, the temperature is 40~60℃ and the time is 2~6h; During the secondary stirring process, the temperature is 40~60℃ and the time is 1~2h; During the three stirring processes, the temperature is 20~30℃ and the time is 0.5~1h.

10. The accelerated deep moisture-curing silane-modified polyether material prepared by the method for preparing accelerated deep moisture-curing silane-modified polyether material according to any one of claims 1 to 9.

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