Preparation method and application of environment-friendly double-component epoxy modified MS sealant

Abstract

The invention mainly relates to the field of environmental protection, and discloses an environment-friendly double-component epoxy modified MS sealant and a preparation method thereof.The preparation method comprises the steps that 100 parts by weight of dimethoxysilyl terminated polypropylene oxide, 5 parts by weight of polyoxypropylene glycol and 60 parts by weight of nano calcium carbonate are evenly mixed at the temperature of 80 DEG C and the vacuum degree of 0.095 MPa; the mixing condition is maintained for 6 hours; and cooling the obtained mixture to below 50 DEG C, adding 6 parts by weight of a polyamide wax thixotropic agent, 10 parts by weight of modified aliphatic amine, 1 part by weight of N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane and 1 part by weight of methyltrimethoxysilane, uniformly mixing under a dry inert gas protection atmosphere, and sealing and packaging according to specifications to obtain a finished product. The component A is modified by epoxy resin, so that the tensile strength and tensile shear strength of the sealant product are greatly improved, the adhesive property is excellent, and the advantages of epoxy resin and polyether modified silane sealant are integrated.

Description

Technical Field

[0001] The invention relates to an environmentally friendly two-component epoxy-modified MS sealant and a preparation method thereof. Background Art

[0002] Sealant materials are materials with both bonding and sealing properties. In recent years, high-performance sealant materials have developed rapidly. They mainly include polysulfide sealants, silicone sealants, polyurethane sealants and silane-modified polyether sealants. Among them, polysulfide sealants have poor aging resistance; silicone sealants have good weather resistance, but poor paintability; polyurethane sealants have strong wear resistance, but long curing time. Epoxy-modified MS sealant is a new type of environmentally friendly polyether-modified silane sealant, which inherits the advantages and strengths of silicone elastic sealants and polyurethane elastic sealants, and also has the excellent insulation, mechanical properties and chemical stability of epoxy resin. It shows excellent weather resistance, durability, high resistance to deformation and displacement, good adhesion, paintability, environmental friendliness, low staining and excellent operating performance. It has the characteristics of green environmental protection and no substrate pollution. It is widely used in prefabricated buildings, transportation, home decoration, aviation and industry.

[0003] Current sealants have the following disadvantages:

[0004] 1. Green and environmentally friendly: Toluene is used as a solvent in the production process of traditional silicone sealants, and toluene will evaporate during use; silicone sealants contain free silicon, which will form silicone oil when used and migrate to the surface of the sealant, absorbing environmental pollutants, especially when used on porous materials such as stone and concrete, which will cause difficult-to-remove pollution to the surrounding area; polyurethane sealants contain isocyanate groups, and TDI and HDI in isocyanates are more volatile and have good fat solubility. If they are accidentally inhaled by the human body, they will denature proteins in the body, destroy cell structures, and even cause suffocation in severe cases; MS sealants do not contain toxic solvents (such as formaldehyde, benzene and toluene) and isocyanate groups, have low VOC content, no free silicon, and will not precipitate pollutants such as silicone oil. They do not corrode or pollute the substrate, and are a green and environmentally friendly MS sealant.

[0005] 2. Storage stability: Single-component MS sealant is moisture-curing, there is no moisture in the sealant system, and the stability is relatively excellent; two-component MS sealant has separate base resin and catalyst, which are mixed when used, ready to use, and has better storage performance; the isocyanate group in the polyurethane sealant will self-polymerize, causing the sealant to fail.

[0006] 3. Adhesion: Among silicone sealants, polyurethane sealants and MS sealants, silicone sealants have relatively weak adhesion, while polyurethane sealants have strong adhesion but need to be used with a primer. Due to the low surface energy and high permeability of the base polymer in MS sealants, it has good adhesion to most inorganic, metal and plastic substrates, and does not require a primer for bonding.

[0007] 4. Paintability: MS sealant will not release oily molecules to pollute the surface and joints of building materials, and can maintain the beauty of the main body of the building for a long time; while traditional silicone sealant will precipitate small molecules, which, together with rainwater and dust, form stains on the facade of the building that are difficult to remove. The main chain of silicone sealant is a silicon-oxygen bond segment, with low molecular polarity and poor adhesion to paint, and the surface cannot be painted. The color can only be kept consistent with the exterior wall paint by adjusting the color of the colloid. The production process is time-consuming and laborious, and the color is difficult to control; MS sealant is compatible with most paints and coatings, and can be directly painted on the surface of the colloid, which can perfectly achieve the uniformity of the exterior wall color and maintain the beauty of the building.

[0008] 5. Stress relaxation: The main chain of MS sealant is a flexible polyether chain segment with excellent mechanical properties and good elasticity, which can solve problems such as joint displacement caused by changes in ambient temperature and collision or stretching between building substrates. When silicone sealant is bonded to porous building substrates, it is easy to cause problems such as peeling of silicone sealant and adhesive parts due to its own insufficient elasticity and expansion of joints.

[0009] 6. Weather resistance: The UV resistance of polyurethane sealant is poor, and it cannot be used in scenes where it is exposed outdoors for a long time. When used, it is necessary to apply a coating on the surface. The urethane structure in the polyurethane molecule is relatively active, while the silane-modified polyether molecular structure is relatively more stable. The cured Si-O-Si segment has strong UV resistance and weather resistance.

[0010] At present, the mainstream synthetic routes of modified silane polyether polymers are mainly:

[0011] 1. One-step method: polyether polyol and isocyanate silane react under the action of catalyst to carry out silane termination;

[0012] 2. Two-step synthesis route of Japan's Zhongyuan Chemical: using allyl polyether alcohol, terminal hydroxyl polyether, etc. as raw materials, dihalomethane as chain extender, caustic soda as catalyst, allyl-terminated polyether intermediates are obtained through chain extension reaction; then, under the action of platinum catalyst, the refined intermediate is reacted with methyldimethoxysilane through terminal silylation reaction to obtain silane-modified polyether polymer;

[0013] 3. First, synthesize a polyurethane prepolymer, and then terminate it with various types of secondary aminopropyltrimethoxy (triethoxy) silane to form a silane-terminated polyether polymer. In summary, the synthesis route of Japan's Zhongyuan Chemical has high equipment requirements and complex processes, and the surface of the obtained low-modulus polymer is sticky after being made into a sealant, and it is easy to absorb dust; due to the introduction of isocyanate groups in the other two synthesis routes, the weather resistance of the obtained sealant becomes poor, and it is easy to turn yellow and crack. The present invention uses epoxy resin to modify the silane-modified polyether sealant, which can greatly improve the bonding strength, bulk strength and hardness of the silane-modified polyether sealant, can be widely bonded to various materials, has high mechanical strength, low shrinkage, excellent electrical insulation performance, good chemical stability, and mildew resistance.

[0014] There is no related patent report yet. Summary of the invention

[0015] Based on this purpose, it is necessary to provide an environmentally friendly epoxy-modified MS sealant and a preparation method thereof, which can be widely used in the fields of prefabricated buildings, transportation, home decoration, aviation and industry, and a MS sealant with low VOC and high mechanical properties.

[0016] The present invention provides an environmentally friendly MS sealant, which mainly comprises component A and component B. In parts by weight, the component A and component B include the following raw materials:

[0017] The A component includes the following raw materials:

[0018]

[0019] The B component comprises the following raw materials:

[0020]

[0021]

[0022] Preferably, the end group of the silane-modified polyether polymer in component A is at least one of methyldimethoxysilane, trimethoxysilane and triethoxysilane; preferably S303H, S203H, SAT200 or SAX400.

[0023] Preferably, the plasticizer in component A is at least one of polyoxypropylene glycol, dioctyl phthalate, dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, chlorinated paraffin 52, and 4,5-epoxytetrahydrophthalic acid (2-ethyl)hexyl ester; preferably polyoxypropylene glycol or octyl phthalate.

[0024] Preferably, the filler in component A is at least one of calcium carbonate, carbon black, kaolin, mica powder, silicon dioxide, titanium dioxide, aluminum hydroxide and calcium oxide; preferably nano calcium carbonate.

[0025] Preferably, the thixotropic agent in component A is at least one of polyamide wax, fumed silica, hydrogenated castor oil, and organic bentonite; preferably polyamide wax or organic bentonite.

[0026] Preferably, the dehydrating agent in the component A is at least one of methoxyvinylsilane, oxazolidine moisture scavenger and molecular sieve; preferably A-171, A-163 or 3A molecular sieve.

[0027] Preferably, the silane coupling agent in the component A is at least one of functional silane compounds such as vinyltrimethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, etc.; preferably KH560, KH550 or KH792.

[0028] Preferably, the epoxy curing agent in component A is at least one of a modified amine compound, anhydride compound or a thiol compound; preferably DMP-30.

[0029] Preferably, the epoxy resin in the B component is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin and o-cresol novolac epoxy resin; preferably bisphenol A epoxy resin 6101, 618 or 634.

[0030] Preferably, the epoxy resin plasticizer in the B component is at least one of polyoxypropylene glycol, dioctyl phthalate, dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, chlorinated paraffin 52, and 4,5-epoxytetrahydrophthalic acid (2-ethyl)hexyl ester; preferably polyoxypropylene glycol.

[0031] Preferably, the thixotropic agent in the B component is at least one of polyamide wax, fumed silica, hydrogenated castor oil and organic bentonite; preferably organic bentonite.

[0032] Preferably, the light stabilizer in the B component is at least one of benzophenone, benzotriazole, salicylate, triazine, substituted acrylonitrile, hindered amine and the like; preferably tinuvin326, tinuvin327 or tinuvin770. The antioxidant is at least one of hindered phenol antioxidant, phosphite antioxidant, thioester antioxidant and composite antioxidant; preferably antioxidant 1010.

[0033] Preferably, the silane-modified polyether polymer catalyst in component B is at least one of an organotin compound or a complex of an organotin compound and an alkylamine; preferably dibutyltin dilaurate, tin octoate, chelated tin, stannous octoate or a tin octoate-laurylamine complex.

[0034] The preparation method of the environmentally friendly two-component epoxy-modified MS sealant comprises the following steps:

[0035] (1) At room temperature, add the silane-modified polyether polymer and plasticizer in component A to a dual planetary power mixer in sequence, and mix them at 60-110° C. and 0.085-0.095 MPa vacuum for 10-20 min; then add the filler and maintain the above mixing conditions, and vacuum stir for 1 h; after the temperature of the obtained mixture is reduced to below 50° C., add the thixotropic agent, silane coupling agent and epoxy curing agent in component A, and vacuum stir for 15-30 min under a dry inert gas protective atmosphere.

[0036] (2) At room temperature, the epoxy resin, plasticizer, light stabilizer and antioxidant in component B are added to a dual planetary power mixer in sequence, and mixed for 20 to 60 minutes under a vacuum degree of 0.085 to 0.095 MPa; then, a silane-modified polyether catalyst is added, and the mixture is stirred in a vacuum for 15 to 30 minutes.

[0037] (3) The method for using the two-component epoxy modified MS sealant according to any one of claims 2 to 12 is characterized in that components A and B are prepared and sealed and packaged according to specifications and are mixed in a weight ratio of 4:1 before use.

[0038] Preferably, the time for maintaining the above mixing conditions in step (1) is 2 to 6 hours.

[0039] The beneficial effects of the present invention are:

[0040] The two-component epoxy-modified MS sealant of the invention has good performance, simple preparation process and is environmentally friendly.

[0041] (1) The present invention adopts epoxy resin modification to greatly improve the tensile strength and tensile shear strength of the sealant product, and has excellent bonding performance, combining the advantages of epoxy resin and polyether modified silane sealant;

[0042] (2) The plasticizer uses polyoxypropylene glycol with excellent flexibility, combined with silane-modified polyether and filler system, so that the sealant has high elasticity after curing;

[0043] (3) In the preparation method, the dehydrating agent and the silane coupling agent are added and dispersed evenly under an inert gas protective atmosphere, thereby avoiding the production problem of high temperature generated during the rubber mixing process and volatilization of the additives under high vacuum, which affects the product weight;

[0044] (4) The epoxy-modified MS sealant of the present invention has both the high strength of epoxy resin glue and the good elongation of MS sealant, high bonding strength, good weather resistance, no primer required, short surface drying time, simple preparation process, environmentally friendly system (dealcoholization curing, no isocyanate), and no harmful substances are discharged from the product from production to use, which meets environmental protection requirements.

[0045] (5) The environmentally friendly two-component epoxy-modified MS sealant prepared by the present invention takes into account the difference in solubility of the silane-modified polyether and the epoxy resin. Separate storage can increase the stability of the sealant performance during storage. Adding an epoxy curing agent to the silane-modified polyether polymer and adding a silane-modified polyether catalyst to the epoxy resin allows the two components to be cured only when mixed, which is beneficial to enhancing the long-term storage stability of the sealant. In addition, compared with the single-component sealant, the two-component sealant has a wider range of filler addition, and the viscosity and strength of the MS sealant can be adjusted more flexibly at a lower cost. DETAILED DESCRIPTION

[0046] Example 1

[0047] An embodiment of a method for preparing the environmentally friendly two-component epoxy-modified MS sealant of the present invention comprises the following steps:

[0048] (1) 100 parts by weight of dimethoxysilyl-terminated polypropylene oxide, 5 parts by weight of polyoxypropylene glycol, and 60 parts by weight of nano-calcium carbonate are mixed uniformly at 80° C. and 0.095 MPa vacuum, and the above mixing conditions are maintained for 6 hours; after the temperature of the obtained mixture is reduced to below 50° C., 6 parts by weight of a polyamide wax thixotropic agent, 10 parts by weight of a modified fatty amine, 1 part by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 1 part by weight of methyltrimethoxysilane are added, and the mixture is mixed uniformly under a dry inert gas protective atmosphere, and sealed and packaged according to specifications to obtain component A;

[0049] (2) 40 parts by weight of bisphenol A epoxy resin, 10 parts by weight of dibutyl phthalate, 6 parts by weight of fumed silica, 1.5 parts by weight of 2-(2-hydroxy-3,5-dibutyl-tert-phenyl)-5-chlorobenzotriazole, 2 parts by weight of 2,6-di-tert-butyl-4-methylphenol, and 5 parts by weight of dibutyltin bis(acetylacetonate) were mixed uniformly, and sealed and packaged according to specifications to obtain component B;

[0050] Components A and B are prepared and stored separately. When used, they are mixed in a weight ratio of 4:1.

[0051] Example 2

[0052] An embodiment of a method for preparing the environmentally friendly two-component epoxy-modified MS sealant of the present invention comprises the following steps:

[0053] (1) 120 parts by weight of trimethoxysilane-terminated polyether, 10 parts by weight of dibutyl phthalate, and 200 parts by weight of nano-calcium carbonate are mixed uniformly at 100° C. and 0.090 MPa vacuum, and the above mixing conditions are maintained for 4 hours; after the temperature of the obtained mixture is reduced to below 50° C., 8 parts by weight of fumed silica, 50 parts by weight of mercaptan, 4 parts by weight of γ-aminopropyltriethoxysilane, and 4 parts by weight of vinyltrimethoxysilane are added, and the mixture is mixed uniformly under a dry inert gas protective atmosphere, and sealed and packaged according to specifications to obtain component A;

[0054] (2) 60 parts by weight of bisphenol A epoxy resin, 15 parts by weight of 4,5-epoxytetrahydrophthalic acid (2-ethyl)hexyl ester, 200 parts by weight of alumina, 8 parts by weight of organic bentonite, 2 parts by weight of 2-(2-hydroxy-3,5-dibutyl-tert-phenyl)-5-chlorobenzotriazole, 1 part by weight of 2,6-di-tert-butyl-4-methylphenol, and 4 parts by weight of dibutyltin dilaurate are mixed uniformly, and sealed and packaged according to specifications to obtain component B;

[0055] Components A and B are prepared and stored separately. When used, they are mixed in a weight ratio of 4:1.

[0056] Example 3

[0057] An embodiment of the method for preparing the two-component epoxy-modified MS sealant of the present invention comprises the following steps:

[0058] (1) 80 parts by weight of dimethoxysilyl-terminated polyether, 20 parts by weight of nano-calcium carbonate, and 70 parts by weight of carbon black are mixed uniformly at 120° C. and a vacuum degree of 0.085 MPa, and the above mixing conditions are maintained for 2 hours; after the temperature of the obtained mixture is reduced to below 50° C., 2 parts by weight of a polyamide wax thixotropic agent, 15 parts by weight of 4,6-(dimethylaminomethyl)triphenol, 2 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 2 parts by weight of vinyltrimethoxysilane are added, and the mixture is mixed uniformly under a dry inert gas protective atmosphere, and sealed and packaged according to specifications to obtain component A;

[0059] (2) 80 parts by weight of bisphenol F epoxy resin, 20 parts by weight of dibutyl phthalate, 160 parts by weight of nano calcium carbonate, 80 parts by weight of calcium oxide, 2 parts by weight of fumed silica, 1 part by weight of 2-(2-hydroxy-3,5-dibutyl-tert-phenyl)-5-chlorobenzotriazole, 1.5 parts by weight of 2,6-di-tert-butyl-4-methylphenol, and 1 part by weight of dibutyltin bis(acetylacetonate) were mixed uniformly, and sealed and packaged according to specifications to obtain component B;

[0060] Components A and B are prepared and stored separately. When used, they are mixed in a weight ratio of 4:1.

[0061] Effect detection: The environmentally friendly two-component epoxy-modified MS sealants prepared in Examples 1 to 3 were subjected to mechanical property tests.

[0062] (1) Tensile strength and elongation: The tensile strength and elongation were evaluated according to GB / T 528-2009 “Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber”.

[0063] (2) Shear strength: The shear strength was evaluated according to GB / T 7124-2008 “Determination of tensile shear strength of adhesives (rigid materials to rigid materials)”.

[0064] Table 1 Properties of environmentally friendly two-component epoxy modified MS sealant

[0065]

[0066] As can be seen from Table 1, the addition of epoxy resin greatly improves the tensile and shear strengths of the entire MS sealant system. At the same time, the two components A and B are packaged separately and mixed evenly in proportion when used, and the formula design is flexible. The two-component epoxy-modified MS sealants prepared in Examples 1 to 3 have excellent elasticity, which is mainly manifested in high tensile strength and high elongation at break, especially in Example 2, whose overall performance is better than similar advanced products.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A two-component epoxy-modified MS sealant, characterized in that: The sealant comprises component A and component B. Component A comprises the following raw materials in parts by weight: The B component includes the following raw materials:

2. The sealant according to claim 1, characterized in that: The end group of the silane-modified polyether polymer in the component A is at least one of methyldimethoxysilane, trimethoxysilane and triethoxysilane; preferably S303H, S203H, SAT200 or SAX400.

3. The sealant according to claim 1, characterized in that: The plasticizer in the component A is at least one of polyoxypropylene glycol, dioctyl phthalate, dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, chlorinated paraffin 52, and 4,5-epoxytetrahydrophthalic acid (2-ethyl) hexyl ester; preferably polyoxypropylene glycol or octyl phthalate.

4. The sealant according to claim 1, characterized in that: The filler in component A is at least one of calcium carbonate, carbon black, kaolin, mica powder, silicon dioxide, titanium dioxide, aluminum hydroxide and calcium oxide; preferably nano calcium carbonate.

5. The sealant according to claim 1, characterized in that: The thixotropic agent in the component A is at least one of polyamide wax, fumed silica, hydrogenated castor oil and organic bentonite; preferably polyamide wax or organic bentonite.

6. The sealant according to claim 1, characterized in that: The dehydrating agent in the component A is at least one of methoxyvinylsilane, oxazolidine moisture scavenger and molecular sieve; preferably A-171, A-163 or 3A molecular sieve.

7. The sealant according to claim 1, characterized in that: The silane coupling agent in the component A is at least one of functional silane compounds such as vinyltrimethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, etc.; preferably KH560, KH550 or KH792.

8. The sealant according to claim 1, characterized in that: The thixotropic agent in the B component is at least one of polyamide wax, fumed silica, hydrogenated castor oil and organic bentonite; preferably organic bentonite.

9. The sealant according to claim 1, characterized in that: The light stabilizer in component B is at least one of benzophenone, benzotriazole, salicylate, triazine, substituted acrylonitrile, hindered amine and other compounds; preferably tinuvin326, tinuvin327 or tinuvin770; the antioxidant is at least one of hindered phenol antioxidant, phosphite antioxidant, thioester antioxidant and composite antioxidant; preferably antioxidant 1010.

10. The method for preparing the environmentally friendly two-component epoxy-modified MS sealant according to any one of claims 1 to 9, comprising the following steps: (1) Add the silane-modified polyether polymer and plasticizer in component A to a dual planetary power mixer in sequence at room temperature, and mix for 10 to 20 minutes at 60 to 110° C. and 0.085 to 0.095 MPa vacuum; then add the filler and maintain the above mixing conditions, and vacuum stir for 1 hour; after the temperature of the obtained mixture is reduced to below 50° C., add the thixotropic agent, silane coupling agent and epoxy curing agent in component A, and vacuum stir for 15 to 30 minutes under a dry inert gas protective atmosphere; (2) Add the epoxy resin, plasticizer, light stabilizer and antioxidant in component B to a dual planetary power mixer in sequence at room temperature, and mix for 20 to 60 minutes under a vacuum degree of 0.085 to 0.095 MPa; then add the silane-modified polyether catalyst and stir in vacuum for 15 to 30 minutes; (3) The method for using the two-component epoxy modified MS sealant according to any one of claims 2 to 12, characterized in that components A and B are prepared and sealed and packaged according to specifications and are mixed in a weight ratio of 4:1 before use; The time for maintaining the above mixing conditions in step (1) is 2 to 6 hours.

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