Organic silicon modified polyurethane resin as well as preparation method and application thereof

Abstract

The invention provides organic silicon modified polyurethane resin as well as a preparation method and application thereof, and relates to the technical field of binders. Specifically, silane modified polyurethane resin with an ester group side chain is prepared on the basis of polyether polyol, hydrogen-containing silicone oil, polyisocyanate, an acrylate compound and an isocyanate silane coupling agent, and the silane modified polyurethane resin with the ester group side chain is used as a resin matrix; the organic silicon modified polyurethane transparent sealant is prepared from the organic silicon modified polyurethane, the composite reinforcing filler, the matting pigment, the antioxidant, the ultraviolet light absorber, the light stabilizer, the moisture scavenger, the tackifier and the catalyst. The silane modified polyurethane resin has the advantages of being high in bonding effect, weather resistance and mechanical strength and the like, and compared with existing products, the transparent sealant has better yellowing resistance, crack resistance and bonding performance and has good application prospects.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and more specifically, to an organosilicon-modified polyurethane resin, its preparation method, and its application. Background Technology

[0002] MS sealant is an environmentally friendly sealant based on silane-modified polyether resin. It combines the characteristics of polyurethane and silicone adhesives, offering excellent adhesion and safety, making it widely used in building sealing and decoration. The original MS resin was invented by Kaneka Corporation of Japan. It is a polymer with a long carbon-oxygen ether chain in the middle segment and trialkoxysilane end caps at both ends. Later, companies such as Wacker Chemie introduced urethane structures by reacting -NCO and -OH to end the long-chain polyether, resulting in SPE resin. However, when used as adhesives, these two resins lack side groups in the middle polyether chain, thus failing to provide sufficient effective adhesion-promoting groups and having limited crosslinking density. This leads to insufficient adhesive strength and a narrow application range, especially for materials like glass and acrylic glass, where adhesion strength is low. Furthermore, insufficient crosslinking can cause surface stickiness and cracking after high temperature and UV exposure, limiting the use of MS sealant in certain applications.

[0003] To address the aforementioned issues and overcome the shortcomings of insufficient adhesive and bulk strength in MS sealant, existing technologies offer the solution of preparing silicone-modified polyurethane resin as the sealant matrix resin. This involves reacting low-molecular-weight polyether polyols and diisocyanates to generate high-molecular-weight hydroxyl-terminated or NCO-terminated polyurethane prepolymers. Finally, a silane coupling agent with amino or NCO groups is used for secondary end-capping, ultimately producing a silane-modified polyurethane resin, known as SPU resin. Currently, sealants prepared using this type of resin are widely used in China. Compared to sealants prepared using resins from the Kaneka and Wacker routes, these sealants offer a wider bonding surface, improved adhesive strength, and lower cost. However, it still has shortcomings such as insufficient adhesion to difficult-to-bond materials, insufficient resin weather resistance, and insufficient tensile strength. In particular, when preparing transparent sealants, since they are directly exposed to sunlight, it is impossible to add different fillers for shielding, and the selection of various weather-resistant additives (antioxidants, UV absorbers, etc.) is narrow due to the transparency requirement. Therefore, transparent sealants made of SPU resin are more prone to yellowing, cracking, and stickiness compared to black and white sealants.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The primary objective of this invention is to provide a method for preparing silicone-modified polyurethane resin, which is mainly used to address the shortcomings of existing MS sealants and their derivative products, such as insufficient adhesion, insufficient weather resistance, and insufficient tensile strength of the silane-modified polyurethane resin (SPU resin, matrix resin).

[0006] A second objective of this invention is to provide an organosilicon-modified polyurethane resin.

[0007] The third objective of this invention is to provide a silicone-modified polyurethane transparent sealant to address the defects of conventional SPU resins in the preparation of transparent sealants, such as easy yellowing, cracking, and sticky surface.

[0008] The fourth objective of this invention is to provide a method for preparing a silicone-modified polyurethane transparent sealant.

[0009] The fifth objective of this invention is to provide an application of the silicone-modified polyurethane resin and / or the silicone-modified polyurethane transparent sealant.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A method for preparing an organosilicon-modified polyurethane resin includes the following steps: An anhydrous mixture comprising polyether polyol and hydrogen-containing silicone oil is prepared. Polyisocyanate and a first catalyst are added dropwise to the anhydrous mixture, and a polymerization reaction is carried out at 70°C to 80°C until the content of isocyanate groups is <0.06 wt.%, to obtain a reaction solution. A solvent is added to the reaction solution, followed by the dropwise addition of an acrylate compound and a second catalyst. An addition reaction is carried out at 40°C to 50°C to obtain an organosilicon-modified polyurethane prepolymer with ester side chains. An isocyanate silane coupling agent is added to the silicone-modified polyurethane prepolymer, and a crosslinking reaction is carried out at 70°C to 80°C. Then, the mixture is placed under vacuum to obtain a silicone-modified polyurethane resin.

[0011] An organosilicon-modified polyurethane resin is prepared using a method comprising the preparation of the organosilicon-modified polyurethane resin described above.

[0012] A silicone-modified polyurethane transparent sealant, comprising the following components in parts by weight: The composition includes 60-100 parts of silicone-modified polyurethane resin, 3-25 parts of reinforcing filler, 0.01-0.5 parts of matting pigment, 0.01-3 parts of antioxidant, 0.01-3 parts of ultraviolet absorber, 0.01-3 parts of light stabilizer, 0.1-10 parts of dehydrating agent, 0.1-10 parts of tackifier, and 0.01-2 parts of catalyst.

[0013] A method for preparing the aforementioned silicone-modified polyurethane transparent sealant includes the following steps: (1) The silicone-modified polyurethane resin, matting pigment, antioxidant, ultraviolet absorber, light stabilizer and part of the dehydrating agent are thoroughly mixed under vacuum to obtain the first mixture; (2) Under a protective atmosphere, reinforcing filler is added to the first mixture in 2 to 5 portions and mixed thoroughly to obtain a second mixture; (3) Under vacuum, the second mixture is processed at 50°C to 60°C using a double planetary mixing apparatus to obtain the third mixture; (4) Under a protective atmosphere, add a tackifier to the third mixture and mix thoroughly, then add a catalyst and the remaining dehydrating agent, and after thorough mixing, obtain a silicone-modified polyurethane transparent sealant.

[0014] Use of at least one of the aforementioned silicone-modified polyurethane resin and the aforementioned silicone-modified polyurethane transparent sealant in building sealing and decoration.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Commercially available silane-modified resins or other existing ester-based silicone-modified polyurethane resins are mostly linear molecules with a high number of ether and CN bonds. After being made into transparent sealants, their weather resistance and strength drop sharply compared to black and white sealants, making them difficult to use for long periods in high-temperature, high-humidity, or high-UV outdoor environments, easily leading to yellowing, brittleness, stickiness, cracking, and other damage. In contrast, this invention provides a silicone-modified polyurethane resin that can be used as a base resin for transparent sealants. It has silicone segments and crosslinkable ester side chains. The ester side chains can react with the amino groups in the silane coupling agent to form an interpenetrating network crosslinked structure, which greatly improves the strength of the sealant after curing. Furthermore, the acrylate groups are strongly polar groups, which helps to enhance the wettability of the resin to the substrate surface, thereby enhancing the adhesive strength. In addition, the silicone segments in the main resin chain also greatly improve the colloid strength and weather resistance, resulting in significant advantages in the cured bulk strength, adhesive strength, and resistance to photothermal aging.

[0016] (2) The organosilicon modified resin of the present invention uses low molecular weight, low viscosity polyether polyol and hydroxyl-terminated silicone oil as raw materials, and has more cross-linking points in the molecular chain, so that the sealant forms a strong cross-linking network at a lower molecular weight. It is not necessary to use plasticizers to improve the production and processing performance. Therefore, there is no risk of plasticizer precipitation, which further improves the overall strength and weather resistance of the sealant.

[0017] (3) Existing SPU resins generally cannot be dehydrated in high-temperature environments above 100°C. During storage and production, moisture is easily introduced and cannot be completely removed, affecting storage stability. In this invention, polyether and hydroxyl silicone oil are used as raw materials. High-temperature dehydration is carried out in the initial synthesis, and the reaction is controlled to be carried out in a protective gas environment throughout the process, so that moisture and air are not introduced, which greatly improves the storage stability of the resin.

[0018] (4) The present invention uses a specific hydroxyl silicone oil with less hydrogen content in its side chain, so the ester side chain formed will not be over-crosslinked and affect the flexibility of the sealant; the organosilicon segments themselves are relatively flexible, and the side groups can easily move on the organosilicon segments and are easy to crosslink; therefore, compared with alkyl side chains, the resin of the present invention is not easy to become brittle after curing, and has less impact on the elongation at break. Moreover, the side groups are all Si-C and CC connected, with high bond energy, and do not contain chemical bonds such as CO and CN that are easy to break, making them difficult to break. Therefore, the colloid itself has high strength, strong resistance to damp heat aging and strong tear resistance.

[0019] (5) The present invention provides a silane-modified polyurethane resin with ester side chains, wherein the ester side chains introduced by the acrylate substances have low surface energy, which makes the wettability of the prepared sealant and the interface more excellent, and the interface affinity will not be reduced due to the introduction of organosilicon segments, and the effect on the adhesiveness of the sealant is small. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. 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. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] The first aspect of this invention is to provide a method for preparing a silicone-modified polyurethane resin. Specifically, in this aspect, a hydroxyl-terminated silicone-modified polyurethane prepolymer with side hydrogen is first prepared by alternating reactions of a hydroxyl-terminated siloxane with side hydrogen, a polyether polyol, and a polyisocyanate; then, an acrylate compound undergoes a hydrosilylation reaction with the hydrogen atoms on the silicone segments of the prepolymer to form a hydroxyl-terminated silicone-modified polyurethane prepolymer with ester side chains; finally, a silane coupling agent with isocyanate is used for the end-capping reaction to prepare a silane-modified polyurethane resin with ester side chains.

[0022] Specifically, this aspect includes the following steps: (1) preparing an anhydrous mixture comprising polyether polyol and hydrogen-containing silicone oil, adding polyisocyanate and a first catalyst dropwise to the anhydrous mixture, and performing a polymerization reaction at 70°C to 80°C until the content of isocyanate groups is <0.06wt.%, to obtain a reaction solution (i.e., a polyurethane prepolymer with side hydrogen, hydroxyl-terminated, and containing organosilicon segments); (2) adding a solvent to the reaction solution, and then adding an acrylate compound and a second catalyst dropwise, and performing an addition reaction at 40°C to 50°C to obtain an organosilicon-modified polyurethane prepolymer with ester side chains; (3) adding an isocyanate silane coupling agent to the organosilicon-modified polyurethane prepolymer, performing a crosslinking reaction at 70°C to 80°C, and then placing it under vacuum to obtain an organosilicon-modified polyurethane resin.

[0023] In one preferred embodiment, the molecular weight of the polyether polyol is 2000-8000, including but not limited to any one or any two of 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, and 8000; in another preferred embodiment, the hydroxyl value of the polyether polyol is 10-60 mg KOH / g.

[0024] In some preferred embodiments, the polyether polyol includes at least one of PPG2000, PPG4000, and PPG8000.

[0025] In a preferred embodiment, the hydrogen-containing silicone oil in this invention refers to a silicone oil that simultaneously contains side-chain hydrogen atoms and hydroxyl groups for termination; the total hydrogen content of the hydrogen-containing silicone oil is 0.08 wt.% to 0.18 wt.%. In some more preferred embodiments, the side-chain hydrogen content of the hydrogen-containing silicone oil is 0.08 wt.% to 0.18 wt.%.

[0026] In one preferred embodiment, the hydrogen-containing silicone oil can be purchased from commercial channels or prepared in-house; in some embodiments, the hydrogen-containing silicone oil is obtained by ring-opening polymerization of tetramethylcyclotetrasiloxane (D4H) and octamethylcyclotetrasiloxane (D4) in an acidic catalyst.

[0027] In a preferred embodiment, the ratio of the amount of polyether polyol to the amount of hydrogen-containing silicone oil added is (4~6):1, based on hydroxyl equivalent.

[0028] In a preferred embodiment, the preparation method of the anhydrous mixture includes the following steps: mixing the polyether polyol and the hydrogen-containing silicone oil under vacuum conditions, heating to 110°C~120°C, and stirring for 2h~4h to obtain the anhydrous mixture. In some more preferred embodiments, the vacuum degree is not lower than -0.095MPa. However, it is worth noting that when using this embodiment, after heating and stirring, the anhydrous mixture needs to be cooled to below 80°C before subsequent dropwise addition and reaction operations can continue.

[0029] In a preferred embodiment, the polyisocyanate includes at least one of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0030] In a preferred embodiment, the first catalyst includes at least one of dibutyltin dilaurate, dibutyltin dioctanoate, and dibutyltin diacetate.

[0031] In a preferred embodiment, the amount of polyisocyanate added is based on the R value, which refers to the ratio of the equivalent number of isocyanate groups (-NCO) in the polyisocyanate to the sum of the equivalent number of active hydrogens (-OH) in the reaction system; the R value is (1.5~2.5):1.

[0032] In a preferred embodiment, the mass ratio of the first catalyst to the total amount of feed is 0.01% to 0.04%, wherein the total amount of feed refers to the total mass of the polyether polyol, the hydrogen-containing silicone oil, the polyisocyanate and the first catalyst.

[0033] In a preferred embodiment, the dropwise addition time of the polyisocyanate and the first catalyst is 1h to 2h, more preferably 1h to 1.5h.

[0034] In a preferred embodiment, the addition of the polyisocyanate and the first catalyst, as well as the polymerization reaction, are carried out in a protective gas environment, including but not limited to nitrogen, helium, neon, argon, etc.; at the same time, the addition of the solvent, the addition reaction, the addition of the isocyanate silane coupling agent, and the crosslinking reaction are also carried out in the above-mentioned protective gas environment.

[0035] It is worth noting that the preparation method of the present invention should strictly control the absence of anhydrous doping or avoid the mixing of moisture in the environment into the reaction. Therefore, apart from the vacuum conditions described in the technical solution, other reaction processes should be set in a protective gas environment as much as possible, while strictly controlling the reaction raw materials to be free of moisture.

[0036] In a preferred embodiment, the polymerization reaction takes 0.8 h to 2 h.

[0037] In a preferred embodiment, the content of the isocyanate groups is tested by hydrochloric acid titration. In this invention, the polymerization reaction time needs to be monitored. If the content of the isocyanate groups is higher than the value defined in this invention, the polymerization reaction continues until the content of the isocyanate groups is lower than 0.06 wt.%.

[0038] In a preferred embodiment, the solvent includes, but is not limited to, toluene, xylene, dimethyl carbonate, etc.

[0039] In a preferred embodiment, the solvent is added after the reaction solution has been cooled to 40°C to 50°C.

[0040] As a preferred embodiment, based on empirical judgment, the volume of the solvent added is 35 vt.% to 50 vt.% of the reaction solution.

[0041] In a preferred embodiment, the acrylate compound includes at least one of methyl acrylate, butyl acrylate, isooctyl acrylate, methyl methacrylate, butyl methacrylate, or hydroxypropyl acrylate.

[0042] In a preferred embodiment, the second catalyst comprises a transition metal compound and its complex, more preferably a platinum catalyst, such as chloroplatinic acid.

[0043] In a preferred embodiment, the amount of acrylate compound added is measured by the alkenyl content and the hydrogen content in the reaction system; specifically, the molar amount of hydrogen in the reaction solution after the addition of solvent is detected by titration, and the molar amount of alkenyl in the acrylate compound to the molar amount of hydrogen is (0.95~1.05):1.

[0044] In a preferred embodiment, the addition reaction takes 0.8 h to 2 h.

[0045] In a preferred embodiment, the isocyanate silane coupling agent includes at least one of 3-isocyanopropyltriethoxysilane, 3-isocyanopropyltrimethoxysilane, 3-isocyanopropylmethyldimethoxysilane, and 1,3,5-tris(trimethoxysilylpropyl)isocyanurate; in some more preferred embodiments, the isocyanate silane coupling agent is 3-isocyanopropyltrimethoxysilane.

[0046] In a preferred embodiment, the mass ratio of the isocyanate silane coupling agent to the organosilicon-modified polyurethane prepolymer is 1 wt.% to 3 wt.%.

[0047] In a preferred embodiment, the crosslinking reaction takes 3 to 5 hours.

[0048] It is worth noting that after a series of feeding and reaction processes under a preferred protective gas environment, the solvent and small molecule volatiles are removed through the vacuum state, thereby obtaining the high-purity organosilicon-modified polyurethane resin.

[0049] A second aspect of the present invention is to provide an organosilicon-modified polyurethane resin, which is prepared by the method for preparing organosilicon-modified polyurethane resin as described in the first aspect.

[0050] A third aspect of the present invention is to provide a silicone-modified polyurethane transparent sealant, comprising the silicone-modified polyurethane resin as described in the second aspect.

[0051] The silicone-modified polyurethane transparent sealant of the present invention comprises the following components by weight: 60-100 parts of the silicone-modified polyurethane resin, 3-25 parts of reinforcing filler, 0.01-0.5 parts of matting pigment, 0.01-3 parts of antioxidant, 0.01-3 parts of ultraviolet absorber, 0.01-3 parts of light stabilizer, 0.1-10 parts of dehydrating agent, 0.1-10 parts of tackifier, and 0.01-2 parts of catalyst.

[0052] As an optional implementation, the mass fractions of each component in the silicone-modified polyurethane transparent sealant include, but are not limited to: 60, 65, 70, 75, 80, 85, 90, 95, and 100 parts of silicone-modified polyurethane resin; 3, 4, 5, 8, 10, 12, 15, 18, 20, 22, and 25 parts of reinforcing filler; 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.45, and 0.5 parts of matting pigment; 0.01, 0.05, 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, and 3 parts of antioxidant; and 0.01 and 0.5 parts of UV absorber. 0.5, 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, 3; light stabilizer 0.01, 0.05, 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, 3; dehydrator 0.1, 0.5, 1, 2, 4, 5, 6, 8, 10; tackifier 0.1, 0.5, 1, 2, 4, 5, 6, 8, 10; catalyst 0.01, 0.02, 0.05, 0.08, 0.1, 0.4, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2; the above mass fractions can be any one of the listed values ​​or any range of two values.

[0053] In a preferred embodiment, the silicone-modified polyurethane transparent sealant comprises the following components by weight percentage: 70%~90% silicone-modified polyurethane resin, 5%~20% reinforcing filler, 0.02%~0.06% matting pigment, 0.1%~1% antioxidant, 0.1%~1% UV absorber, 0.1%~1% light stabilizer, 1%~5% dehydrating agent, 1%~5% tackifier, and 0.1%~0.5% catalyst.

[0054] In a preferred embodiment, the reinforcing filler includes at least one of hydrophilic fumed silica or hydrophobic fumed silica, more preferably hydrophobic fumed silica.

[0055] In a more preferred embodiment, the specific surface area (BET) of the reinforcing filler is 100 m². 2 / g~200m 2 / g; In another preferred embodiment, the reinforcing filler is pretreated with a surface treatment agent, wherein the surface treatment agent is a chlorosilane. As another preferred embodiment, the reinforcing filler should be dried at 60°C to 80°C for at least 24 hours before use to remove moisture from the filler particles.

[0056] In a preferred embodiment, the matting pigment includes at least one of indigo blue, phthalocyanine blue, phthalocyanine green, cobalt chromium blue, or cobalt chromium green. In this invention, a small amount of the matting pigment can be selected and added according to actual conditions for color masking, reducing ultraviolet absorption, and improving the yellowing defect of the colloidal substance.

[0057] In a preferred embodiment, the antioxidant includes, but is not limited to, hindered phenolic antioxidants; the ultraviolet absorber includes, but is not limited to, benzotriazole ultraviolet absorbers; and the light stabilizer includes, but is not limited to, hindered amine light stabilizers. In this invention, the above three types of additives can respectively improve the sealant's antioxidant, light aging resistance, and heat aging resistance properties, giving the sealant good weather resistance and greatly reducing the risk of aging failure of transparent sealants when used outdoors.

[0058] In a preferred embodiment, the dehydrating agent includes at least one of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriisopropoxysilane, or methylvinyldimethoxysilane; the present invention improves the storage stability of the adhesive by absorbing residual moisture that may be present in the colloid through the dehydrating agent.

[0059] In a preferred embodiment, the tackifier includes at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-diethylenetriaminopropyltrimethoxysilane. The present invention improves the crosslinking speed and density of the colloid through the tackifier, enhances the adhesion strength of the adhesive to various substrate surfaces, and improves the bulk strength of the cured adhesive.

[0060] In a preferred embodiment, the catalyst includes at least one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, or chelated tin, more preferably dibutyltin dilaurate; the present invention improves the curing speed and curing depth of the adhesive through the catalyst, and after the moisture is thoroughly removed, it is beneficial to improve the storage stability of the sealant.

[0061] The fourth aspect of the present invention is to provide a method for preparing a silicone-modified polyurethane transparent sealant as described in the third aspect, which mainly includes the following steps (1) to (4).

[0062] (1) The silicone-modified polyurethane resin, matting pigment, antioxidant, ultraviolet absorber, light stabilizer and part of the dehydrating agent are thoroughly mixed under vacuum to obtain the first mixture.

[0063] In a preferred embodiment, the vacuum level of the vacuum state is not lower than -0.095 MPa.

[0064] In a preferred embodiment, in step (1), the amount of the dehydrating agent added is 1 / 2 to 3 / 4 of its total volume.

[0065] In a preferred embodiment, in step (1), the thorough mixing is carried out at 35°C to 50°C.

[0066] As a preferred embodiment, in step (1), the thorough mixing is carried out by means of oscillation, stirring, shaking, centrifugation, ultrasound, etc., which helps to accelerate dispersion and obtain a relatively uniform dispersion system.

[0067] (2) Under a protective atmosphere, reinforcing filler is added to the first mixture in 2 to 5 portions and mixed thoroughly to obtain the second mixture.

[0068] In a preferred embodiment, in step (2), the thorough mixing is carried out at 40°C to 60°C.

[0069] As a preferred embodiment, in step (2), the thorough mixing is carried out by means of oscillation, stirring, shaking, centrifugation, ultrasound, etc., which helps to accelerate dispersion and obtain a relatively uniform dispersion system.

[0070] (3) Under vacuum, the second mixture is processed at 50°C to 60°C using a double planetary mixing apparatus to obtain the third mixture.

[0071] In a preferred embodiment, the processing time in step (3) is 1h to 3h.

[0072] As a preferred embodiment, steps (1) to (2) are performed in the dual planetary mixing apparatus to avoid the complex operation of changing the container of the reaction system in this step.

[0073] In a preferred embodiment, the stirring speed of the dual planetary mixer is 30 rpm to 100 rpm, and the dispersion speed of the dual planetary mixer is 1000 rpm to 2000 rpm. It is worth understanding that the above stirring and dispersion speeds correspond to the rotational speeds of the low-speed stirring component and the high-speed dispersion component of this specific type of equipment, respectively.

[0074] (4) Under a protective atmosphere, add a tackifier to the third mixture and mix thoroughly, then add a catalyst and the remaining dehydrating agent, and after thorough mixing, obtain a silicone-modified polyurethane transparent sealant.

[0075] As a preferred embodiment, step (4) is performed at 30°C to 40°C.

[0076] In a preferred embodiment, step (4) includes the following steps: adding a tackifier to the third mixture under a protective atmosphere, and then stirring and mixing under vacuum; then adding a catalyst and the remaining dehydrating agent under a protective atmosphere, and then stirring and mixing under vacuum; finally, filling with a protective gas to equalize the pressure, to obtain a silicone-modified polyurethane transparent sealant. In a more preferred embodiment, the stirring and mixing are carried out for 20 min to 60 min respectively.

[0077] The fifth aspect of the present invention is to provide the use of silicone-modified polyurethane resin as described in the second aspect or silicone-modified polyurethane transparent sealant as described in the third aspect in building sealing and decoration; it is worth noting that the use includes, but is not limited to, the use of the above two products, other adhesive products based on the above two products, and construction methods of other adhesive products based on the above two products, etc., and no strict limitations are imposed on the use in the present invention.

[0078] Example 1 S1. Add 30g D4H, 70g D4 and 1.5g concentrated sulfuric acid to a flask, heat to 80℃, stir and react for 5h. Dissolve the product in toluene, neutralize with calcium carbonate and wash with water until neutral, then remove water by separation. Then remove water from the toluene with anhydrous sodium sulfate as a dehydrating agent. After centrifugation and filtration to remove solid impurities, remove the toluene by rotary evaporation. Finally, place the product in a vacuum drying container at 50℃ and dry for 12h to obtain hydroxyl-terminated hydrogen-containing silicone oil.

[0079] Then, 500g of polyether polyol PPG2000 (hydroxyl equivalent of 100g / eq) and 50g of hydrogen-containing silicone oil were added to a double planetary mixing vessel, maintaining the hydroxyl equivalent ratio of polyether to hydrogen-containing silicone oil at 5:1. The temperature was raised to 120℃, and the vacuum was drawn to a vacuum degree of not less than -0.095MPa. The mixture was stirred to remove water for 3 hours.

[0080] S2. Reduce the material temperature to 70℃. Under nitrogen protection, slowly add 200g of hexamethylene diisocyanate (molecular weight 168g / mol) and 0.02% of dibutyltin dilaurate by weight of the total feed into the mixing vessel, maintaining the ratio of -NCO:-OH in the mixing vessel at 1:2 (to ensure excess hydroxyl groups). Add the mixture dropwise at 75℃ for 1.2h to generate a polyurethane prepolymer containing organosilicon segments.

[0081] S3. After the addition is complete, continue the reaction for 1 hour. The residual amount of -NCO in the prepolymer is determined by hydrochloric acid titration to be 0.05 wt.

[0082] S4. Lower the reactor temperature to 45℃ and add 300g of toluene solvent to the mixing reactor. At this point, the system viscosity is 4200mPa·s. Slowly add 0.01% of the total mass of platinum catalyst (chloroplatinic acid) and 0.5g (1wt.% of the amount of hydrogen-containing silicone oil) of methyl methacrylate to the mixing reactor, controlling the molar ratio of C=C to hydrogen in the acrylate to be 1:1, and carry out the addition reaction of vinyl and silane. After 1 hour of reaction, an organosilicon-modified polyurethane prepolymer with ester side chains is generated.

[0083] S5. Under nitrogen protection, 3% of the total mass of isocyanate silane coupling agent (3-propyltriethoxysilane) was added to the mixing vessel, and the temperature was raised to 75°C for 4 hours. After that, the solvent and small molecule volatiles were removed by vacuuming to obtain the organosilicon modified polyurethane resin of this embodiment.

[0084] Example 2 It is basically the same as Example 1, except that in S1 the ratio of hydroxyl equivalents of polyether to hydrogen-containing silicone oil is controlled to be 6:1.

[0085] Example 3 The process is basically the same as in Example 1, except that in S2, the addition is carried out dropwise at 70°C for 1.5 hours, and in S3, the reaction continues for 0.8 hours after the addition is completed.

[0086] Example 4 The process is basically the same as in Example 1, except that in S2, the addition is carried out at 80°C for 1 hour, and in S3, the reaction continues for 2 hours after the addition is completed.

[0087] Example 5 The results are basically the same as in Example 1, except that: hexamethylene diisocyanate in S2 is replaced with toluene diisocyanate, methyl methacrylate in S4 is replaced with isooctyl acrylate, and 3-propyltriethoxysilane in S5 is replaced with 1,3,5-tris(trimethoxysilylpropyl)isocyanurate.

[0088] Test case A corresponding silicone-modified polyurethane transparent sealant was prepared using the silicone-modified polyurethane resin as described in Example 1. The mass percentage formulation of the sealant in this experimental example is as follows: silicone-modified polyurethane resin: 80%, reinforcing filler: 10%, matting pigment: 0.04%, antioxidant: 0.3%, ultraviolet absorber: 0.4%, light stabilizer: 0.3%, dehydrating agent: 5.33%, tackifier: 3.33%, catalyst: 0.3%.

[0089] S2-1. Add antioxidant (BASF 1010), two-thirds by mass of dehydrating agent (vinyltrimethoxysilane, KH-171), matting pigment (indigo blue), ultraviolet absorber (BASF Tinuvin 234), and light stabilizer (BASF Tinuvin B 75) to the prepared silicone-modified polyurethane resin mixing vessel. Heat the mixture to 40°C in the double planetary mixing vessel. During the heating process, turn on the vacuum pump, ensuring the vacuum level is not lower than -0.095 MPa. Turn on the slow stirring (20 rpm) and stir for 20 minutes to rapidly preheat and mix evenly.

[0090] S2-2. Turn off the agitator and the vacuum system, fill with protective nitrogen to equalize the pressure, and add the dried reinforcing filler (hydrophobic fumed silica, Shandong Hongruitong, HD-171) to the mixing vessel in three batches while it is still hot. Turn on the agitator (40 rpm) and the bottom dispersion unit (1000 rpm) to quickly mix the filler into the resin base. During this period, the temperature inside the vessel should be maintained at 50℃.

[0091] S2-3. After the filler is completely mixed in, maintain the temperature at 55℃, turn on the vacuum, increase the stirring (40 rpm) and dispersion speed (150 rpm), and disperse at high speed for 2 hours.

[0092] S2-4. After dispersion, lower the reactor temperature to 35℃. Purge with nitrogen to maintain pressure, and under nitrogen protection, add the thickener (γ-aminopropyltriethoxysilane) to the mixing vessel. Vacuum the vessel and stir for 30 minutes to ensure uniform mixing. Maintain the reactor temperature at 35±2℃ throughout this process.

[0093] S2-5. Purge with nitrogen to maintain pressure, control the temperature at 35°C, and under nitrogen protection, add the remaining one-third of the dehydrating agent and all of the catalyst (dibutyltin dilaurate) to the mixing vessel. Vacuum the vessel, and turn on the stirring assembly (20 rpm) and bottom dispersion assembly (500 rpm) for 30 minutes to ensure uniform mixing. After mixing, turn off the vacuum, purge with protective nitrogen to maintain pressure, and discharge the material to obtain the sealant of this embodiment.

[0094] Example: A commercially available transparent nail-free adhesive The appearance, properties, and performance of the silicone-modified polyurethane transparent sealant in the above test examples were tested, and the results are recorded in Table 1.

[0095] The testing methods for each test item are as follows: The appearance color was determined visually; the surface drying time was determined according to GB / T 13477.5-2002 "Test Methods for Building Sealing Materials - Part 5: Determination of Surface Drying Time"; the hardness was determined according to GB / T 531.1-2008 "Test Methods for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber - Part 1: Shore Hardness Tester Method (Shore Hardness)"; the curing depth was determined by filling the mold cavity with sealant at 23±2℃ and 50±5%RH, and recording the depth from the exposed surface to the cured part after 24 hours; the shear strength was determined according to GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives (Rigid Material to Rigid Material)"; the tensile strength and elongation at break were determined according to GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber"; the thermal aging performance and xenon lamp aging performance were determined according to GB / T 18244-2022 "Aging Test Methods for Building Waterproofing Materials".

[0096] Table 1

[0097] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for preparing an organosilicon-modified polyurethane resin, characterized in that, Includes the following steps: An anhydrous mixture comprising polyether polyol and hydrogen-containing silicone oil with side-hydrogen-terminated hydroxyl groups was prepared. Polyisocyanate and a first catalyst were added dropwise to the anhydrous mixture, and a polymerization reaction was carried out at 70°C to 80°C until the content of isocyanate groups was <0.06 wt.%, thus obtaining a reaction solution. A solvent is added to the reaction solution, followed by the dropwise addition of an acrylate compound and a second catalyst. An addition reaction is carried out at 40°C to 50°C to obtain an organosilicon-modified polyurethane prepolymer with ester side chains. An isocyanate silane coupling agent is added to the silicone-modified polyurethane prepolymer, and a crosslinking reaction is carried out at 70°C to 80°C. Then, the mixture is placed under vacuum to obtain a silicone-modified polyurethane resin.

2. The method for preparing the organosilicon-modified polyurethane resin according to claim 1, characterized in that, The ratio of the amount of polyether polyol to the amount of hydrogen-containing silicone oil added, based on hydroxyl equivalent, is (4~6):1; And / or, the ratio of the equivalent number of isocyanate groups in the polyisocyanate to the sum of the equivalent number of active hydrogens in the anhydrous mixture is taken as the R value, where the R value is (1.5~2.5):

1.

3. The method for preparing the organosilicon-modified polyurethane resin according to claim 1, characterized in that, The method for preparing the anhydrous mixture includes: mixing the polyether polyol and the hydrogen-containing silicone oil under vacuum conditions, heating to 110°C~120°C, and stirring for 2h~4h to obtain the anhydrous mixture; Preferably, the addition time of the polyisocyanate and the first catalyst is 1h to 2h; Preferably, the polymerization reaction takes 0.8 h to 2 h.

4. The method for preparing the organosilicon-modified polyurethane resin according to claim 1, characterized in that, The molar amount of hydrogen in the reaction solution after the addition of solvent was determined by titration, and the ratio of the molar amount of alkenyl groups of the acrylate compound to the molar amount of hydrogen was (0.95~1.05):

1. Preferably, the addition reaction takes 0.8 h to 2 h.

5. The method for preparing the organosilicon-modified polyurethane resin according to claim 1, characterized in that, The polyisocyanate includes at least one of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and polymethylene polyphenyl polyisocyanate; And / or, the acrylate compounds include at least one of methyl acrylate, butyl acrylate, isooctyl acrylate, methyl methacrylate, butyl methacrylate, or hydroxypropyl acrylate; And / or, the isocyanate silane coupling agent includes at least one of 3-isocyanopropyltriethoxysilane, 3-isocyanopropyltrimethoxysilane, 3-isocyanopropylmethyldimethoxysilane, and 1,3,5-tris(trimethoxysilylpropyl)isocyanurate.

6. An organosilicon-modified polyurethane resin, characterized in that, It is prepared by a method comprising the preparation of organosilicon-modified polyurethane resin as described in any one of claims 1 to 5.

7. A silicone-modified polyurethane transparent sealant, characterized in that, Includes the following components by weight: The product comprises 60-100 parts of the silicone-modified polyurethane resin as described in claim 6, 3-25 parts of reinforcing filler, 0.01-0.5 parts of matting pigment, 0.01-3 parts of antioxidant, 0.01-3 parts of ultraviolet absorber, 0.01-3 parts of light stabilizer, 0.1-10 parts of dehydrating agent, 0.1-10 parts of tackifier, and 0.01-2 parts of catalyst.

8. The silicone-modified polyurethane transparent sealant according to claim 7, characterized in that, Includes at least one of the following features (a) to (f): (a) The reinforcing filler includes at least one of hydrophilic fumed silica or hydrophobic fumed silica; (b) The matting pigment includes at least one of indigo blue, phthalocyanine blue, phthalocyanine green, cobalt chromium blue, or cobalt chromium green; (c) The antioxidant includes hindered phenolic antioxidants; the ultraviolet absorber includes benzotriazole ultraviolet absorbers; the light stabilizer includes hindered amine light stabilizers; (d) The dehydrating agent includes at least one of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriisopropoxysilane or methylvinyldimethoxysilane; (e) The tackifier comprises at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-diethylenetriaminopropyltrimethoxysilane; (f) The catalyst comprises at least one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, or chelated tin.

9. The method for preparing the organosilicon-modified polyurethane transparent sealant as described in claim 7 or 8, characterized in that, Includes the following steps: (1) The silicone-modified polyurethane resin, matting pigment, antioxidant, ultraviolet absorber, light stabilizer and part of the dehydrating agent are thoroughly mixed under vacuum to obtain the first mixture; (2) Under a protective atmosphere, reinforcing filler is added to the first mixture in 2 to 5 portions and mixed thoroughly to obtain a second mixture; (3) Under vacuum, the second mixture is processed at 50°C to 60°C using a double planetary mixing apparatus to obtain the third mixture; (4) Under a protective atmosphere, add a tackifier to the third mixture and mix thoroughly, then add a catalyst and the remaining dehydrating agent, and after thorough mixing, obtain a silicone-modified polyurethane transparent sealant.

10. Use of at least one of the silicone-modified polyurethane resin of claim 6 and the silicone-modified polyurethane transparent sealant of claim 7 or 8 in building sealing and decoration.

Images