Low-viscosity non-toxic silane-terminated polyether resin and preparation method therefor

Abstract

The present invention belongs to the technical field of sealants. Disclosed are a low-viscosity non-toxic silane-terminated polyether resin and a preparation method therefor. The preparation method for the silane-terminated polyether resin comprises: with succinic anhydride and a polyether polyol as raw materials, preparing a polymer under the catalysis of an acid catalyst; adding N-hydroxysuccinimide and a carbodiimide-type catalyst to the polymer, stirring and reacting same; and dropwise adding an aminoalkoxysilane coupling agent to the system for termination, so as to prepare the silane-terminated polyether resin. The present invention uses the cheap succinic anhydride and polyether polyol for reaction, so as to achieve chain extension and also convert the hydroxyl at the terminal end of the polyether polyol into carboxyl having higher activity, thereby facilitating subsequent modification; the present invention avoids isocyanate-based coupling agents or tin-series catalysts which are expensive and toxic, thus being safe and nontoxic; and the obtained silane-terminated resin contains only two amide bonds on the terminal end, which effectively reduces the viscosity of products, thus facilitating the subsequent use of the products.

Description

Low viscosity non-toxic silane-terminated polyether resin and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of sealant, in particular to a low viscosity non-toxic silane-terminated polyether resin and a preparation method thereof. BACKGROUND

[0002] As a very important type of moisture-curable resin, silane-terminated resin has a wider bonding property to substrates due to the alkoxysilane connected to the end of the main chain, compared with other moisture-curable resins, and is widely used in the fields of automobile industry, electronics and electrical appliances, civil engineering, new energy, solar photovoltaic, etc. Compared with polyurethane resin, silane-terminated resin does not produce bubbles during the curing process, thus does not affect the mechanical properties of the material, and the Si-O-Si molecular chain after curing has strong ultraviolet resistance and weather resistance, and there is no free isocyanate and organic solvent in the silane-modified polymer product, which is harmless to the environment, and is more in line with the development trend of green environmental protection theme and new type of elastic sealing material in today's world.

[0003] Specifically, silane-terminated resins can be divided into two categories, silane-modified polyether (MS) and silane-modified polyurethane (SPU), according to the main chain. MS resin was first prepared by KANEKA in Japan using the traditional method of dihalomethane chain extension. The method first uses monoallyl polyether alcohol and hydroxyl-terminated polyether as raw materials, dihalomethane as a chain extender, and alkali metal hydroxide as a catalyst to increase the molecular weight, then uses allyl halide to terminate the hydroxyl group, desalts and refines to obtain bis-allyl-terminated polyether, and then uses bis-allyl-terminated polyether and alkoxy silane under the action of platinum catalyst to undergo hydrosilylation to obtain MS resin. AGC company in Japan then uses allyl chloride chain extension method to prepare MS resin. It first uses small molecule alcohol as a starter, and then uses ethylene oxide or propylene oxide to undergo ring-opening polymerization under the action of double metal cyanide complex catalyst to prepare hydroxyl-terminated high molecular weight polyether polyol. Then, using allyl chloride in the presence of sodium methoxide and other alkoxide reagents, the double bond of the polyether polyol is terminated to prepare high molecular weight bis-allyl polyether polyol. Finally, using methyl dimethoxysilane and high molecular weight bis-allyl polyether polyol under the action of platinum catalyst, hydrosilylation is carried out to prepare MS resin. The above two methods both involve the process of allylation of polyether, which is complicated and needs multiple purification and refining. The high viscosity makes it difficult to mix raw materials, and the synthesis efficiency is low. Therefore, the above method can only obtain low relative molecular mass and wide distribution of bis-allyl-terminated polyether, and the conversion rate of high relative molecular mass bis-allyl polyether is low. SPU resin was first developed by GE company in the United States. It uses tin catalyst to catalyze siloxane containing isocyanate group (-NCO) to directly terminate the end hydroxyl polyether or polyester diol to obtain SPU resin by one-step method. This method is simple, easy to operate and control product viscosity, and the molecular weight distribution of the product is also relatively concentrated. However, the price of -NCO-containing alkoxysilane is relatively high, which greatly increases the production cost, and the types of such special alkoxysilane on the market are limited, which greatly limits the application of this method. At present, the mainstream method for producing SPU resin is two-step method. This process first uses polyether or polyester diol to react with diisocyanate to obtain polyurethane prepolymer, and then uses functional siloxane to terminate the polyurethane prepolymer. Compared with one-step method, this method reduces the production cost to some extent, but the use of secondary amine silane coupling agent for termination introduces a large amount of amide bond (-CO-NH-) into the system, which makes it easy to form hydrogen bonds between and within molecules, and then leads to rapid increase of system viscosity, which is not conducive to later application. Chinese patent CN107955571A uses mercaptan alkoxysilane to terminate -NCO or isothiocyanate alkoxysilane to terminate -OH, and uses thioamide (-CS-NH-) instead of amide bond (-CO-NH-) to effectively reduce the viscosity of the system. However, the price of mercaptan alkoxysilane and isothiocyanate alkoxysilane is very expensive and the types are rare.

[0004] Therefore, it is necessary to provide a simple and easy-to-operate, low-viscosity and non-toxic silane-terminated polyether resin and a preparation method thereof. SUMMARY

[0005] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of low-viscosity and non-toxic silane-terminated polyether resin. The silane-terminated polyether resin prepared by the preparation method has only two amide bonds at the terminal, can effectively reduce the viscosity of the product, is conducive to the application of the product, and does not introduce toxic coupling agents or catalysts, which is safe and non-toxic.

[0006] To solve the above problems, the technical scheme adopted by the present application is as follows:

[0007] A preparation method of low-viscosity and non-toxic silane-terminated polyether resin, which uses succinic anhydride and polyether polyol as raw materials, and a polymer is prepared under the catalysis of an acid catalyst; N-hydroxysuccinimide and a carbodiimide catalyst are added to the polymer for stirring reaction, and an aminoalkoxy silane coupling agent is added dropwise to the system for end-capping, so as to prepare the silane-terminated polyether resin.

[0008] As a preferred embodiment of the present application, the preparation method specifically comprises the following steps:

[0009] S1, polyether polyol is placed under vacuum dehydration at 110-120 DEG C for more than 1h; succinic anhydride and an acid catalyst are added to the polyether polyol, and stirring is carried out under nitrogen atmosphere until the temperature is raised to 120-180 DEG C, and the system is kept at this temperature for 4-6h; during the reaction process, when the system changes from turbidity to homogeneous transparent and the acid value is basically unchanged, the system is kept at this temperature for 0.5-1.5h, degassing and cooling to below 60 DEG C, and then the polymer is obtained by filtration;

[0010] S2, N-hydroxysuccinimide and a carbodiimide catalyst are added to the polymer prepared in step S1, and stirring is carried out under nitrogen atmosphere until the temperature is raised to 120-140 DEG C, and the temperature is kept stable for 0.5-1h; then the temperature is lowered to 70-80 DEG C, and an aminoalkoxy silane coupling agent is added dropwise to the system, and the system is kept at this temperature for 1.5-2h; then the temperature is lowered to below 60 DEG C, and the silane-terminated polyether resin is obtained by filtration.

[0011] As a preferred embodiment of the present application, the acid catalyst is one or more of phosphoric acid, phosphorous acid, p-toluenesulfonic acid, phosphotungstic acid and strong acid cation exchange resin. More preferably, the strong acid cation exchange resin has a more excellent catalytic effect, and compared with conventional acid catalysts such as p-toluenesulfonic acid, the strong acid cation exchange resin has a lower dosage, can be removed from the system by simple filtration, and can be reused.

[0012] As a preferred embodiment of the present application, the carbodiimide catalyst is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, N-cyclohexyl-N'-(2-morpholinoethyl)carbodiimide methy p-toluenesulfonate.

[0013] As a preferred embodiment of the present application, the molecular weight of the polyether polyol is 2000-8000 g / mol.

[0014] Further preferably, the polyether polyol is one of PPG, PEG, a mixture of PPG and PEG, or a copolymer of EG and PG.

[0015] As a preferred embodiment of the present application, the molar ratio of the polyether polyol to succinic anhydride is 1:1.5-1.8.

[0016] As a preferred embodiment of the present application, the amount of the acid catalyst is 0.5-1.5% of the total weight of all the mixture in step S1.

[0017] As a preferred embodiment of the present application, the molar ratio of the carboxyl in the polymer, the amino in the aminoalkoxy coupling agent, N-hydroxysuccinimide, and the carbodiimide catalyst is 1:2:2:2-2.5.

[0018] The second object of the present application is to provide a low-viscosity non-toxic silane-terminated polyether resin prepared by the preparation method described above.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] (1) The present application uses inexpensive succinic anhydride to react with polyether polyol, which not only extends the chain but also converts the terminal hydroxyl group of polyether alcohol into a more active carboxyl group, facilitating subsequent modification and modification. At the same time, during the chain extension process of succinic anhydride on polyether and the subsequent process of alkoxysilane termination of polyether, neither expensive and toxic isocyanate coupling agent nor toxic tin catalyst is used, making the prepared silane-terminated resin safe and non-toxic.

[0021] (2) The silane-terminated resin prepared by the preparation method of the present application has only two amide bonds (-CO-NH-) at the terminal, which can effectively reduce the viscosity of the product and facilitate the subsequent application of the product.

[0022] In summary, the preparation method of the present application is simple and easy to operate, and the preparation process does not introduce toxic dihaloalkane, tin catalyst and isocyanate and other substances into the system, which is safe and environmentally friendly. The prepared silane-terminated resin product has low viscosity and is convenient for subsequent use. DETAILED DESCRIPTION

[0023] A preparation method of low viscosity and non-toxic silane-terminated polyether resin, which comprises the following steps: first, preparing a polymer by using succinic anhydride and polyether polyol as raw materials and under the catalysis of an acid catalyst; then, adding N-hydroxysuccinimide (NHS) and a carbodiimide catalyst into the polymer and stirring to react; and finally, adding an aminoalkoxy silane coupling agent dropwise into the system to terminate the reaction and obtain the silane-terminated polyether resin. The reaction process involved in the preparation method is as follows:

[0024] In the above reaction equation, the molecular weight of the polyether polyol is 2000-8000 g / mol; the polyether polyol is one of PPG, PEG, a mixture of PPG and PEG, or a copolymer of EG and PG; R1 is -CH3 or -H. The acid catalyst is at least one of phosphoric acid, phosphorous acid, p-toluenesulfonic acid, phosphotungstic acid, and a strongly acidic cation exchange resin. The carbodiimide catalyst is at least one of 1-ethyl-(3-dimethylaminopropyl) carbodiimide (EDC), N,N'-dicyclohexyl carbodiimide (DCC), N,N'-diisopropyl carbodiimide (DIC), and N-cyclohexyl-N'-(2-morpholinoethyl) carbodiimide methanesulfonic acid salt (CMC). The aminoalkoxy coupling agent is a commonly available commercial aminoalkoxy coupling agent, in which R2 is -CH3, -CH2CH3, -OCH3, -OCH2CH3, etc., R3 is -OCH3, -OCH2CH3, etc., and R4 is -C3H6-, -C3H6-NH-C3H6-, etc.

[0025] The preparation method specifically comprises the following steps:

[0026] S1, polyether polyol is placed in a vacuum dehydrator at 110-120℃ for more than 1h; succinic anhydride and an acid catalyst are added to the polyether polyol, and the system is stirred and heated to 120-180℃ under a nitrogen atmosphere; the reaction process is continued for 3-6h, during which the system changes from turbidity to homogeneous transparency and the acid value remains basically unchanged; the system is further incubated for 0.5-1.5h, degassed, and cooled to below 60℃; the product is filtered and discharged to obtain a polymer; wherein the molar ratio of polyether polyol to succinic anhydride is 1:1.5-1.8, and the amount of acid catalyst is 0.5-1.5% of the total weight of all the mixture in step S1;

[0027] S2, adding N-hydroxysuccinimide and carbodiimide catalyst to the polymer prepared in step S1, stirring under nitrogen atmosphere, heating to 120-140℃, stabilizing temperature for 0.5-1h, cooling to 70-80℃, adding aminoalkoxy silane coupling agent dropwise to the system, incubating for 1.5-2h, cooling to below 60℃, and filtering to obtain the silane-terminated polyether resin. The molar ratio among the carboxyl in the polymer, the amino in the aminoalkoxy coupling agent, N-hydroxysuccinimide and the carbodiimide catalyst is 1:2:2:2-2.5.

[0028] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0029] Example 1

[0030] A method for preparing a low-viscosity non-toxic silane-terminated polyether resin, comprising the following steps:

[0031] S1, adding 1000g of polypropylene glycol (molecular weight 2000g / mol) to a reaction kettle, vacuum dehydrating at 120℃ for 2h. Then adding 75g of succinic anhydride and an appropriate amount of acid catalyst to the system, purging with nitrogen three times, continuing to heat to 130±5℃ under a nitrogen atmosphere of 0.2Mpa, incubating for 3h until the system becomes homogeneous and transparent and the acid value of the system remains basically unchanged, continuing to incubate for 0.5h, then starting to degas and cool, and filtering to obtain a high-molecular-weight polyester diacid.

[0032] Under the above process conditions, different acid catalysts are selected to prepare high-molecular-weight polyester diacid intermediates A-D, and the number average molecular weight and molecular weight distribution are shown in Table 1.

[0033] Table 1 Test results of dynamic viscosity of polyester diacids of the same molecular weight prepared by different acid catalysts

[0034] Note: The percentage here is relative to the total weight of all the mixture in step S1

[0035] S2, taking 500g of the polymer A obtained in step S1 and adding it to a reaction kettle, then adding 24.75g of N-hydroxysuccinimide and 38.75g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide, purging with nitrogen three times, stirring under nitrogen atmosphere, heating to 125℃, incubating for 1h, then cooling to 70-80℃, adding 44.75g of 3-aminopropyltrimethoxysilane dropwise to the system, purging with nitrogen at 0.2Mpa, incubating for 1.5h, cooling to below 60℃, and filtering to obtain the silane-terminated polyether.

[0036] Example 2

[0037] A method for preparing a low-viscosity non-toxic silane-terminated polyether resin, comprising the following steps:

[0038] S1, 1000g polypropylene glycol (molecular weight 5000g / mol) was added to a reaction kettle, vacuum dehydration at 120°C for 2h. Then 32g succinic anhydride and 8.26g strong acid cation exchange resin were added to the system, placed under nitrogen three times, continue to heat to 135±5°C under the atmosphere of 0.2Mpa nitrogen, and keep for 4h. The system became homogeneous and transparent, and the acid value of the system was basically unchanged. Continue to keep for 0.5h, then start to degas and cool. Filter to obtain high molecular weight polyester diacid.

[0039] S2, 500g polymer obtained in step S1 was added to a reaction kettle, then 9.9g N-hydroxysuccinimide and 17.44g 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole were added, placed under nitrogen three times, stirred and heated to 125°C under nitrogen atmosphere, kept for 1h, then cooled to 70-80°C, 17.9g 3-aminopropyltrimethoxysilane was added dropwise to the system, kept for 1.5h under 0.2Mpa nitrogen, and cooled to below 60°C. Filter to obtain silane-terminated polyether.

[0040] Example 3

[0041] A method for preparing a low-viscosity non-toxic silane-terminated polyether resin, comprising the following steps:

[0042] S1, 1000g polypropylene glycol (molecular weight 5000g / mol) was added to a reaction kettle, vacuum dehydration at 120°C for 2h. Then 32g succinic anhydride and 8.26g strong acid cation exchange resin were added to the system, placed under nitrogen three times, continue to heat to 135±5°C under the atmosphere of 0.2Mpa nitrogen, and keep for 4h. The system became homogeneous and transparent, and the acid value of the system was basically unchanged. Continue to keep for 0.5h, then start to degas and cool. Filter to obtain high molecular weight polyester diacid.

[0043] S2, 500g polymer obtained in step S1 was added to a reaction kettle, then 9.9g N-hydroxysuccinimide and 17.44g 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole were added, placed under nitrogen three times, stirred and heated to 125°C under nitrogen atmosphere, kept for 1h, then cooled to 70-80°C, 17.9g 3-aminopropyltrimethoxysilane was added dropwise to the system, kept for 1.5h under 0.2Mpa nitrogen, and cooled to below 60°C. Filter to obtain silane-terminated polyether.

[0044] Example 4

[0045] The difference between this example and Example 1 is that 1000g polyethylene glycol (molecular weight 8000g / mol) is added to the reaction kettle in step S1.

[0046] Comparative Example 1

[0047] The comparative example was prepared by using conventional diisocyanate chain extension method to prepare silane-terminated polyether resin, and the preparation method is as follows:

[0048] 1000 g of polyether polyol (molecular weight 16000 g / mol, functionality 2) was added to a reaction kettle, and vacuum dehydration was carried out at 120°C for 2-3 h. Then, the temperature was lowered to below 50°C, 21.75 g of toluene diisocyanate was added, and the reaction polymerization was carried out at a reaction temperature of 80°C for 3 h to obtain a polyurethane prepolymer. Then, 26.85 g of 3-aminopropyltrimethoxysilane was added to the polyurethane prepolymer, and the system was reacted at 80°C for 2-3 h under nitrogen atmosphere to obtain a silane-terminated polyether resin.

[0049] Comparative Example 2

[0050] The difference between the present comparative example and Comparative Example 1 is that 25.2 g of 1,6-hexane diisocyanate was added during chain extension.

[0051] Comparative Example 3

[0052] The present comparative example was prepared by using alcohol esterification reaction to carboxylate polyether polyol, and then glycidyl ether alkoxy silane was used to terminate to prepare silane-terminated polyether resin, and the preparation method is as follows:

[0053] 500 g of polypropylene glycol ether diol (molecular weight 4000 g / mol, structure as follows: wherein R is linear or branched C1-C10 alkoxy, x is much larger than y, and both are integers) was added to a three-necked flask equipped with a stirrer and a thermometer, and vacuum extraction was carried out at 100°C for 2 h. The temperature was continuously raised to 200°C, and 33.5 g of terephthalic acid was added. After reaction for 1 h, vacuum extraction was continued for 5 h to obtain a carboxyl-terminated polyether.

[0054] The temperature of the above reaction was lowered to 110°C, 47.2 g of γ-glycidyl ether propyltrimethoxysilane and 8.7 g (total weight 0.8%) of triphenylphosphine catalyst were added, and the reaction was continued for 2 h. The temperature was lowered to 50°C, and the product was discharged to obtain a silane-terminated polyether.

[0055] Comparative Example 4

[0056] The present comparative example was prepared by using acid anhydride ring-opening reaction to carboxylate polyether polyol, and then glycidyl ether alkoxy silane was used to terminate to prepare silane-terminated polyether resin, and the preparation method is as follows:

[0057] 500 g of polypropylene glycol ether diol (molecular weight 4000 g / mol, structure as follows: wherein R is a linear or branched C1-C10 alkoxy group, x is much greater than y, and both are integers, the temperature is raised to 100°C and vacuumed for 1 h, the temperature is continuously raised to 130°C, 37 g of phthalic anhydride is added, and the reaction is carried out for 2 h to obtain a carboxyl-terminated polyether.

[0058] The temperature of the above reaction is lowered to 120°C, 59 g of γ-glycidoxypropyltrimethoxysilane and 2.98 g (0.5% of the total weight) of a secondary amine catalyst are added, and the reaction is continued for 2 h, the temperature is lowered to 50°C, and the product is discharged to obtain a silane-terminated polyether.

[0059] I. Test of dynamic viscosity

[0060] The silane-terminated polyether resins prepared in Examples 1-4 and Comparative Examples 1-4 are tested for dynamic viscosity, and the results are shown in Table 2.

[0061] Table 2. Test results of dynamic viscosity of silane-terminated polyether resins prepared in Examples 1-4 and Comparative Examples 1-4

[0062] As shown in Table 2, under the same molecular weight, the product prepared by the method provided in the application has a narrower molecular weight distribution (less than 1.1) and a smaller dynamic viscosity, indicating that the preparation method of the application can effectively reduce the viscosity of the product and make the molecular weight distribution of the product more concentrated.

[0063] II. Test of application performance

[0064] The silane-terminated polyether resins prepared in Example 3 and Example 4, Comparative Example 1 and Comparative Example 2 are used to prepare moisture-curing sealant according to the formulations shown in Table 2.

[0065] Table 2. Formulation table of moisture-curing sealant

[0066] The moisture-curing sealant is prepared according to the formulations shown in Table 2, and the specific method is as follows:

[0067] The GCC, PCC, silane-terminated polyether resin, coupling agent, plasticizer and thixotropic agent are put into a mixing drum, and a double-planetary mixer is used to stir until there are no particles in the mixture in the mixing drum; then the system is heated to 110-130°C, vacuumed and kept for 2-3 h; then the temperature is lowered to below 60°C, the vacuum is stopped, and the water removal agent and catalyst are added, stirred uniformly, and then the sealant is defoamed to obtain the moisture-curing sealant.

[0068] The moisture-curing sealants prepared by using the silane-terminated polyether resins of Example 3 and Example 4, Comparative Example 1 and Comparative Example 2 as raw materials are tested for extrusion property, surface drying time, tensile strength, elongation at break and hardness, and the specific tests refer to the following standards:

[0069] 1. Extrudability: Refer to GB 16776-2005 "Structural sealant silicone for building";

[0070] 2. Surface dry time: Refer to GB / T 13477.5-2002 "Test methods for building sealant materials Part 5: Determination of surface dry time";

[0071] 3. Tensile strength: Refer to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized or thermoplastic rubbers";

[0072] 4. Elongation at break: Refer to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized or thermoplastic rubbers";

[0073] 5. Hardness: Refer to GBT 531.1-2008 "Determination of indentation hardness of vulcanized or thermoplastic rubbers Part 1: Durometer method (Shore hardness)".

[0074] The results are shown in Table 3.

[0075] Table 3. Performance test results of moisture curing sealant

[0076] It can be seen from the results shown in Table 1 and Table 3 that, under the condition of the same number average molecular weight, the silane-terminated polyether resin of Example 3 has lower dynamic viscosity, so that the moisture curing sealant prepared by using the same has significantly better extrudability than the moisture curing sealant prepared by using the silane-terminated polyether resin prepared by the conventional diisocyanate chain extension method, and even better tensile strength and elongation at break than the conventional product with aromatic ring reinforcement, which is of great significance to the preparation of sealing materials.

[0077] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and substitutions made by those skilled in the art on the basis of the present application are within the scope of protection of the present application.

Claims

1. A process for the preparation of a low viscosity, non-toxic, silane-terminated polyether resin, characterized in that: The silane-terminated polyether resin is prepared by using succinic anhydride and polyether polyol as raw materials, and under the catalysis of an acid catalyst, adding N-hydroxysuccinimide and a carbodiimide catalyst to the polymer for stirring reaction, and adding an aminoalkoxy silane coupling agent dropwise into the system for end-capping.

2. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin as claimed in claim 1, wherein: Specifically comprising the following steps: S1, polyether polyol is placed under vacuum dehydration at 110-120℃ for more than 1h; succinic anhydride and an acid catalyst are added to the polyether polyol, and the system is stirred and heated to 120-180℃ under a nitrogen atmosphere, and kept for 4-6h; during the reaction, when the system changes from turbidity to homogeneous transparency and the acid value is basically unchanged, the system is kept for 0.5-1.5h, degassed and cooled to below 60℃, and the product is filtered and discharged to obtain a polymer; S2, N-hydroxysuccinimide and a carbodiimide catalyst are added to the polymer prepared in step S1, and the system is stirred and heated to 120-140℃ under a nitrogen atmosphere, and kept at the stable temperature for 0.5-1h; the system is cooled to 70-80℃, an aminoalkoxy silane coupling agent is added dropwise into the system, and kept for 1.5-2h; the system is cooled to below 60℃, and filtered to obtain the silane-terminated polyether resin.

3. A process for the preparation of low viscosity, nontoxic, silane-terminated polyether resins according to claim 1 or 2, characterized in that: The acid catalyst is one or more of phosphoric acid, phosphorous acid, p-toluenesulfonic acid, phosphotungstic acid, and a strongly acidic cation exchange resin.

4. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin according to claim 1 or 2, characterized in that: The carbodiimide catalyst is one or more of 1-ethyl-(3-dimethylaminopropyl) carbodiimide, N,N'-dicyclohexyl carbodiimide, N,N'-diisopropyl carbodiimide, and N-cyclohexyl-N'-(2-morpholinoethyl) carbodiimide methyl p-toluenesulfonate.

5. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin according to claim 1 or 2, characterized in that: The molecular weight of the polyether polyol is 2000-8000g / mol.

6. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin as claimed in claim 5, wherein: The polyether polyol is one of PPG, PEG, a mixture of PPG and PEG, or a copolymer of EG and PG.

7. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin according to claim 1 or 2, characterized in that: The molar ratio of the polyether polyol to succinic anhydride is 1:1.5-1.

8.

8. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin according to claim 1 or 2, characterized in that: The amount of the acid catalyst is 0.5-1.5% of the total weight of all the mixtures in step S1.

9. The process for the preparation of low viscosity, nontoxic, silane-terminated polyether resin according to claim 1 or 2, characterized in that: The molar ratio of the carboxyl group in the polymer, the amino group in the aminoalkoxy coupling agent, N-hydroxysuccinimide, and the carbodiimide catalyst is 1:2:2:2-2.

5.

10. A low viscosity, non-toxic, silane-terminated polyether resin characterized by: It is prepared by the preparation method of any one of claims 1-9.

Images