Preparation method of amphiphilic silane modified block type organic silicon ether

Abstract

The invention provides a preparation method of amphiphilic silane modified block type organic silicon ether, which is characterized in that ABA block type organic silicon polyether is selected as a main chain, the A segment is a hydrophilic hydroxyl-terminated polyether chain segment, and the B segment is a hydrophobic organic silicon chain segment, so that uniform and alternate distribution of hydrophilic and hydrophobic areas is ensured from the aspect of molecular design. The ABA block type structure realizes molecular-level uniform distribution of a hydrophilic segment and a hydrophobic segment, and endows the material with excellent surface conditioning ability, compatibility and dispersion stability; the monomer residue is extremely low, and the monomer residue is extremely low (lt; 0.01%), and the environmental protection requirement of low VOC (volatile organic compounds) is met; a high-activity silane group at a chain end enables the product to have rapid room-temperature moisture curing film-forming ability; the method has controllable conditions and is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a method for preparing amphiphilic silane-modified block organosilicon ethers. Background Technology

[0002] In the fields of polymer materials, adhesives, and coatings, organosilicon polyethers are widely used due to the low surface energy of organosilicon and the flexibility and hydrophilicity of polyethers. However, existing organosilicon polyethers are hydroxyl-terminated, resulting in significant deficiencies in their curing properties, which restricts their further development.

[0003] On the other hand, traditional silane-modified polyethers are mostly linear or single-structured, resulting in a singular or uneven distribution of hydrophilic and hydrophobic structures, severely limiting the application range of the materials. Although silane end-capping technology can improve the adhesion between the polymer and the substrate and the curing performance to some extent, the existing traditional preparation process uses organotin or organobismuth catalysts, resulting in high monomer residues and insufficient curing performance. These defects make the materials perform poorly in terms of interfacial compatibility, dispersion stability, curing effect, and storage stability, failing to meet the needs of related fields for high-performance materials.

[0004] Therefore, there is a need for a method to prepare block polymers that achieve low monomer residue, uniform amphiphilicity, and efficient silane end-capping to solve the above problems, thereby expanding the range of applications, such as for use in stain-resistant coatings and leather coatings. Summary of the Invention

[0005] The objective of this invention is to disclose a method for preparing amphiphilic silane-modified block organosilicon ethers. By selecting ABA block organosilicon polyether as the main chain, wherein segment A is a hydrophilic hydroxyl-terminated polyether segment and segment B is a hydrophobic organosilicon segment, the uniform and alternating distribution of hydrophilic and hydrophobic regions is ensured from the molecular design perspective.

[0006] To achieve the above objectives, this invention discloses a method for preparing amphiphilic silane-modified block organosilicon ethers, comprising the following steps:

[0007] Step 1: Under an inert atmosphere, mix 80-100 parts of ABA block silicone polyether with 12-18 parts of diisocyanate chain extender and 2-17 parts of silane compound containing isocyanate functional groups, add titanium metal salt catalyst and heat to react until the isocyanate functional groups are completely reacted to obtain silane-terminated prepolymer.

[0008] Step 2: Remove low-boiling substances to obtain silane-terminated organosilicon polyether modified resin.

[0009] In some embodiments, the ABA block silicone polyether, wherein A is a polyether segment and is hydroxyl-terminated, having at least one polyether repeating unit, and B is a silicone segment.

[0010] In some embodiments, the molecular weight of the ABA block silicone polyether ranges from 600 to 20,000.

[0011] In some embodiments, the diisocyanate chain extender is one or a combination of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0012] In some embodiments, the silane compound containing the isocyanate functional group is one or a combination of several of propyltriethoxysilane, propyltrimethoxysilane, and ethyltrimethoxysilane.

[0013] In some embodiments, the titanium metal salt catalyst is one of tetrabutyl titanate, isopropyl titanate, and diisopropyloxybis(ethoxyacetyl)phthalide.

[0014] In some embodiments, the reaction temperature in step one is 60-90°C.

[0015] In some embodiments, the monomer residual content of the silane-terminated organosilicon polyether modified resin is less than 0.01%.

[0016] In some embodiments, the silane-terminated organosilicon polyether modified resin can be cured into a film at room temperature.

[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) The ABA block structure achieves a uniform molecular-level distribution of hydrophilic and hydrophobic segments, giving the material excellent surface conditioning ability, compatibility and dispersion stability; (2) Extremely low monomer residue (<0.01%), which meets the environmental protection requirements of low VOC (volatile organic compounds); (3) The highly active silane groups at the chain end enable the product to have rapid room temperature moisture curing film formation ability; (4) The conditions are controllable and suitable for industrial production. Detailed Implementation

[0018] The following embodiments provide a detailed description of the present invention. However, it should be noted that these embodiments are not intended to limit the present invention. Any equivalent substitutions or replacements in function, method, or structure made by those skilled in the art based on these embodiments are within the scope of protection of the present invention.

[0019] This invention uses a specially designed ABA block polymer as the main chain, and through the precise chain extension and end-capping reaction of carefully selected chain extenders and silane end-capping agents under the action of a highly efficient titanium metal salt catalyst, a homogeneous, highly active, and low-residue amphiphilic silane-modified polymer is synthesized.

[0020] Example 1

[0021] The raw material in this embodiment is ABA-type organosilicon polyether, specifically XIAMETER. TM OFX-3667 (A-terminus is polydimethylsiloxane segment, B-terminus is polyether segment, hydroxyl equivalent is 1200 g / eq), the diisocyanate chain extender is IPDI (isophorone diisocyanate), the silane reagent is propyltriethoxysilane isocyanate (IPTES), and the catalyst is tetrabutyl titanate.

[0022] Under an inert gas atmosphere, 83 parts of ABA-type organosilicon polyether were stirred until homogeneous, and then 15 parts of isophorone diisocyanate and 2 parts of propyltriethoxysilane isocyanate were slowly added, followed by 300 ppm of catalyst. The reaction was carried out at 65°C for 3 hours. The reaction was stopped after the NCO absorption peak disappeared, as monitored by infrared spectroscopy.

[0023] After cooling to room temperature, low-boiling substances were removed to obtain silane-terminated organosilicon polyether modified resin.

[0024] The resin has a viscosity of 6000 cP, can be cured into a film within 24 hours under humid conditions, has a tensile strength of 3.0 MPa, a surface contact angle of up to 105°, and is easy to clean with a smooth feel.

[0025] Example 2

[0026] The raw materials in this embodiment are: ABA-type organosilicon polyether Shin-Etsu X-22-4952 (viscosity 100cst hydroxyl value 50mgKOH / g), diisocyanate chain extender toluene diisocyanate, silane reagent ethyltrimethoxysilane isocyanate, and catalyst tetraisopropyl titanate.

[0027] Under an inert gas atmosphere, 85 parts of ABA-type organosilicon polyether were stirred until homogeneous, and then 12 parts of toluene diisocyanate and 2 parts of ethyltrimethoxysilane isocyanate were slowly added, followed by 200 ppm of catalyst. The reaction was carried out at 80°C for 2 hours. The reaction was stopped after the NCO absorption peak disappeared, as monitored by infrared spectroscopy.

[0028] After cooling to room temperature, low-boiling substances were removed to obtain silane-terminated organosilicon polyether modified resin.

[0029] The resin has a viscosity of 4000 cP and can cure into a film within 24 hours under humid conditions, making it suitable for preparing low-VOC adhesives.

[0030] Example 3

[0031] The raw materials in this embodiment are: ABA-type organosilicon polyether Shin-Etsu X-22-4272 (viscosity 270cst, hydroxyl value 50mgKOH / g), diisocyanate chain extender is diphenylmethane diisocyanate, silane reagent is propyltrimethoxysilane isocyanate, and catalyst is diisopropoxybis(ethoxyacetyl)phthalide.

[0032] Under an inert gas atmosphere, 80 parts of ABA-type organosilicon polyether were stirred until homogeneous, and then 18 parts of isophorone diisocyanate and 3 parts of propyltriethoxysilane isocyanate were slowly added, followed by 200 ppm of catalyst. The reaction was carried out at 60°C for 4 hours. The reaction was stopped after the NCO absorption peak disappeared, as monitored by infrared spectroscopy.

[0033] After cooling to room temperature, low-boiling substances were removed to obtain silane-terminated organosilicon polyether modified resin.

[0034] The resin has a viscosity of 10,000 cP and can cure into a film within 24 hours under humid conditions. It has excellent stain resistance and is easy to clean.

[0035] Example 4

[0036] The raw material in this embodiment is ABA-type organosilicon polyether, specifically XIAMETER. TM OFX-3667 (A-terminus is a polydimethylsiloxane segment, B-terminus is a polyether segment, hydroxyl equivalent is 1200 g / eq), the silane reagent is propyltrimethoxysilane isocyanate, and the catalyst is tetrabutyl titanate.

[0037] Under an inert gas atmosphere, 100 parts of ABA-type organosilicon polyether were stirred until homogeneous, and 17 parts of propyltrimethoxysilane isocyanate were slowly added, followed by 200 ppm of catalyst. The reaction was carried out at 80°C for 2 hours. The reaction was stopped after the NCO absorption peak disappeared, as monitored by infrared spectroscopy.

[0038] After cooling to room temperature, low-boiling substances were removed to obtain silane-terminated organosilicon polyether modified resin.

[0039] The resin has a viscosity of 800 cP and can be used to prepare low-VOC adhesives and coatings.

[0040] Comparative Example 1

[0041] The difference from Example 3 is that the catalyst is a bismuth salt catalyst, preferably triacetylbismuth or other bismuth organic salts.

[0042] Performance testing

[0043] The initial viscosity, aging viscosity, residual monomer content, storage stability, tensile strength, and hardness of the resins in Examples 1-4 and the comparative examples were tested, and the results are shown in the table below.

[0044] Table 1 shows the resin performance tests for Examples 1-4 and the comparative examples.

[0045]

[0046] As shown in Table 1, the silane-terminated reaction rate of organosilicon ethers is significantly reduced and the isocyanate group conversion time is prolonged under the bismuth salt catalyst system. The monomer residual level is higher than that when using the titanium salt catalyst, exceeding 0.3%, and the storage stability is relatively poor.

[0047] The preparation method disclosed in this invention uses ABA block-type organosilicon polyether as the main chain, wherein segment A is a hydrophilic hydroxyl-terminated polyether segment and segment B is a hydrophobic organosilicon segment. This structure ensures a uniform and alternating distribution of hydrophilic and hydrophobic regions from a molecular design perspective.

[0048] Chain extenders: Diisocyanate compounds (such as IPDI, TDI, MDI) are used to connect ABA backbone molecules, increasing molecular weight. Silane end-capping agents: Silane compounds containing isocyanate functional groups (such as IPTES, IPTMS, IETMS) are used. Their isocyanate groups (-NCO) react with the hydroxyl groups (-OH) of the backbone, simultaneously introducing hydrolyzable alkoxysilane groups to the polymer chain ends, giving it moisture-curing properties.

[0049] Catalyst: Titanium metal salt catalysts (such as tetrabutyl titanate and tetraisopropyl titanate) are preferred over traditional bismuth salt catalysts to ensure high reaction efficiency and low monomer residue.

[0050] During the preparation process, ensure the reaction is carried out under an inert atmosphere (such as nitrogen protection) to prevent side reactions. Control the reaction temperature within a suitable range of 60-90℃, and monitor the reaction progress in real time using infrared spectroscopy (IR) (tracking the disappearance of the characteristic peak of the -NCO group) to ensure complete reaction.

[0051] After the reaction is completed, a post-treatment step is performed to remove low-boiling substances under reduced pressure, further removing unreacted monomers and byproducts.

[0052] This invention solves the problem of uneven distribution of hydrophilic / hydrophobic segments in traditional linear polymers, improving the interfacial compatibility and overall performance of the material; reduces monomer residues during the preparation process to meet the requirements of environmental protection and high-quality products; improves the curing performance of the polymer, including curing speed and crosslinking density after curing; improves the application performance of the final product, such as stain resistance, feel, strength, and compatibility with other resin systems; and enhances the storage stability of the product, ensuring that the product's performance does not degrade during storage.

[0053] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0054] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing an amphiphilic silane-modified block organosilicon ether, characterized in that, Includes the following steps: Step 1: Under an inert atmosphere, mix 80-100 parts of ABA block silicone polyether with 12-18 parts of diisocyanate chain extender and 2-17 parts of silane compound containing isocyanate functional groups, add titanium metal salt catalyst and heat to react until the isocyanate functional groups are completely reacted to obtain silane-terminated prepolymer. Step 2: Remove low-boiling substances to obtain silane-terminated organosilicon polyether modified resin.

2. The method for preparing amphiphilic silane-modified block organosilicon ethers according to claim 1, characterized in that, The ABA block type organosilicon polyether, wherein A is a polyether segment and is hydroxyl-terminated, having at least one polyether repeating unit, and B is an organosilicon segment.

3. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 2, characterized in that, The molecular weight range of the ABA block type organosilicon polyether is 600-20000.

4. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 1, characterized in that, The diisocyanate chain extender is one or a combination of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

5. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 1, characterized in that, The silane compound containing the isocyanate functional group is one or a combination of several of propyltriethoxysilane, propyltrimethoxysilane, and ethyltrimethoxysilane.

6. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 1, characterized in that, The titanium metal salt catalyst is one of tetrabutyl titanate, isopropyl titanate, and diisopropyloxybis(ethoxyacetyl)phthalide.

7. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 1, characterized in that, In step one, the reaction temperature is 60-90℃.

8. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 1, characterized in that, The monomer residual content of the silane-terminated organosilicon polyether modified resin is less than 0.01%.

9. The method for preparing amphiphilic silane-modified block organosilicon ether according to claim 8, characterized in that, The silane-terminated organosilicon polyether modified resin can be cured into a film at room temperature.

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