Two-component hollow sealant and preparation method thereof

Abstract

The invention discloses a two-component hollow sealant and a preparation method thereof. The two-component hollow sealant comprises a component A, a component B, a component C and a component D, wherein the component A comprises polycyclopropane dihydric alcohol, isocyanate, filler and a plasticizer; the component B comprises filler, a silane coupling agent, a catalyst and a molecular sieve; polycyclopropane dihydric alcohol is selected as a soft segment, isocyanate is selected as a hard segment, and a modified silane coupling agent, a plasticizer and kaolin are added as fillers to improve the mechanical strength and weather resistance of the sealant; according to the coupling agent, an alkoxy chain with surface activity is introduced to triethoxysilane through a hydrosilylation method, a novel silane coupling agent carrying active groups is prepared, the surface tension of the novel silane coupling agent has excellent surface activity, and the novel silane coupling agent can better react with a polyurethane system.

Description

Technical Field

[0001] The invention relates to the technical field of sealants, and in particular to a two-component hollow sealant and a preparation method thereof. Background Art

[0002] Sealant is a paste-like or high-viscosity sealing material that deforms with the shape of the sealing surface, is not easy to flow, has a certain degree of adhesion, and is used to fill the gap between joints. It has both sealing and bonding functions. In the mid-20th century, sealants were mainly used in aerospace and other fields. In the 1980s, sealants began to be used to seal building joints. Generally, sealants are required to smooth the joints of cement materials such as airport runways, highways and buildings. At present, the main sealants used are silicone, polysulfide, and polyurethane. Among them, silicone sealant products account for more than 60% of the use of building sealants in my country.

[0003] The most important representative of organic silicon is silicone sealant, which is a paste made of polydimethylsiloxane as the main raw material, with cross-linking agent, plasticizer, silane coupling agent, catalyst, and filler mixed in a vacuum state. It is a liquid silicone rubber (RTV) that condenses and solidifies with water vapor in the air (or a two-component mixture) at room temperature. This silicone sealant has stable performance, but it has low strength, poor adhesion to bonding materials, and is expensive.

[0004] Polysulfide sealant is made of polysulfide rubber, curing agent and compounding agent. This kind of sealant has low elastic modulus, is easy to age, is expensive, has bad smell, and is difficult to meet the needs of construction.

[0005] Compared with the above two types of sealants, polyurethane sealants have the advantages of high mechanical strength, high low-temperature toughness, excellent wear resistance, strong bonding performance, good elasticity, and excellent weather resistance. Polyurethane sealants also have some disadvantages. For example, under high temperature conditions, urethane is easy to decompose, and under low temperature conditions, polyurethane sealants tend to become brittle, thereby reducing the bonding strength and easily separating from the substrate. Because polyurethane contains urethane groups, ester groups, and urea groups, the presence of these groups makes it hydrophilic and reduces its water resistance.

[0006] Therefore, the preparation method and related technologies of polyurethane sealants still need to be further improved. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a two-component hollow sealant and a preparation method thereof, which solves the problems of poor weather resistance, poor hardness and low tensile strength of the sealant in the prior art.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] On the one hand, the present invention provides a two-component hollow sealant, comprising the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0010] On this basis, further preferably, the silane coupling agent is formed by the reaction of triethoxysilane, N-aminoethylpiperazine and a platinum catalyst.

[0011] On this basis, further preferably, the preparation method of the silane coupling agent comprises the following steps:

[0012] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 80-85° C. for 3-5 hours to obtain the silane coupling agent.

[0013] On this basis, further preferably, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.27-1.45.

[0014] On this basis, further preferably, the platinum catalyst includes chloroplatinic acid and hexachloroplatinic acid.

[0015] On this basis, further preferably, the platinum catalyst accounts for 12-15% of the mass of the triethoxysilane.

[0016] On this basis, further preferably, the isocyanate includes at least one of toluene diisocyanate TDI and diphenylmethane-4-4'-diisocyanate MDI.

[0017] On this basis, further preferably, the filler includes kaolin or calcium carbonate.

[0018] On this basis, further preferably, the plasticizer comprises phthalate.

[0019] On this basis, further preferably, the catalyst is tetramethylbutanediamine or triethylenediamine.

[0020] On this basis, it is further preferred that the molecular sieve is 4A molecular sieve.

[0021] In a second aspect, the present invention further provides a method for preparing the two-component hollow sealant according to the first aspect, comprising the following steps:

[0022] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 40-45°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0023] Preparation of component B: Stirring filler, silane coupling agent, catalyst and molecular sieve at 40-45° C. to obtain component B;

[0024] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0025] On this basis, more preferably, the mass ratio of component A to component B is 9-10:1.

[0026] On this basis, more preferably, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.14-1.25.

[0027] On this basis, it is further preferred that the mass ratio of filler, silane coupling agent, catalyst and molecular sieve is 23-35:11-14:0.7-0.9:6.3-9.7.

[0028] On this basis, more preferably, the stirring condition is 4500-6000 rpm, and the stirring is 12-16 min.

[0029] The two-component hollow sealant and the preparation method thereof of the present invention have the following advantages over the prior art:

[0030] Beneficial effects:

[0031] (1) The present invention selects polycyclopropane diol and isocyanate to prepare a two-component hollow sealant, selects polycyclopropane diol as a soft segment, isocyanate as a hard segment, and adds a modified silane coupling agent, a plasticizer and kaolin as a filler to improve the mechanical strength and weather resistance of the sealant; an alkoxy chain with surface activity is introduced into triethoxysilane by the hydrosilylation method to prepare a new silane coupling agent carrying an active group, whose surface tension has excellent surface activity and better reacts with a polyurethane system.

[0032] (2) The present invention designs the ratio of the -NCO group of isocyanate to the -OH group of polycyclopropane diol, i.e., the effect of the n(-NCO / -OH) value on the mechanical properties, thermal stability and water absorption of the polyurethane sealant. The results show that when the ratio is 1.27, the mechanical properties of the polyurethane sealant are the best, and the tensile strength and elongation at break are the best;

[0033] (3) In the reaction of the prior art, water vapor in the air will enter the reaction system and react with the isocyanate group in most cases, resulting in the formation of small lumps on the surface of the prepolymer and a decrease in the -NCO content in the prepolymer components. At the same time, molecular sieves are added to effectively avoid the side reactions of isocyanate MDI and the hydroxyl groups of water. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The invention provides a two-component hollow sealant and a preparation method thereof. By designing the ratio of -NCO groups of isocyanate to -OH groups of polycyclopropane diol, a surface-active alkoxy chain is introduced into triethoxy hydrogen silicon by using the hydrosilylation method, so as to prepare a novel silane coupling agent carrying active groups. The surface tension of the silane coupling agent has excellent surface activity and can react better with a polyurethane system.

[0036] Example 1

[0037] A two-component hollow sealant comprises the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0038] In this embodiment, specifically, the isocyanate includes diphenylmethane-4-4'-diisocyanate MDI.

[0039] In this embodiment, specifically, the filler includes kaolin.

[0040] In this embodiment, specifically, the plasticizer includes phthalate.

[0041] In this embodiment, specifically, the catalyst is tetramethylbutanediamine or triethylenediamine.

[0042] In this embodiment, specifically, the molecular sieve is 4A molecular sieve.

[0043] In this embodiment, specifically, the silane coupling agent is formed by the reaction of triethoxysilane, N-aminoethylpiperazine and a platinum catalyst.

[0044] In this embodiment, specifically, the preparation method of the silane coupling agent comprises the following steps:

[0045] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 80° C. for 3 h to obtain the silane coupling agent.

[0046] In this embodiment, specifically, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.27.

[0047] In this embodiment, specifically, the platinum catalyst includes chloroplatinic acid.

[0048] In this embodiment, specifically, the platinum catalyst accounts for 12% of the mass of the triethoxysilane.

[0049] Specifically, the preparation method of the two-component hollow sealant comprises the following steps:

[0050] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 40°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0051] Preparation of component B: stirring a filler, a silane coupling agent, a catalyst and a molecular sieve at 40° C. to obtain component B;

[0052] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0053] In this embodiment, more specifically, the mass ratio of the A component to the B component is 9:1.

[0054] In this embodiment, more specifically, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.14.

[0055] In the present embodiment, more specifically, the mass ratio of the filler, the silane coupling agent, the catalyst and the molecular sieve is 23:11:0.7:6.3.

[0056] In this embodiment, more specifically, the stirring condition is 4500 rpm for 12 minutes.

[0057] Example 2

[0058] A two-component hollow sealant comprises the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0059] In this embodiment, specifically, the isocyanate includes toluene diisocyanate TDI.

[0060] In this embodiment, specifically, the filler includes kaolin or calcium carbonate.

[0061] In this embodiment, specifically, the plasticizer includes phthalate.

[0062] In this embodiment, specifically, the catalyst is tetramethylbutanediamine.

[0063] In this embodiment, specifically, the molecular sieve is 4A molecular sieve.

[0064] In this embodiment, specifically, the preparation method of the silane coupling agent comprises the following steps:

[0065] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 85° C. for 5 hours to obtain the silane coupling agent.

[0066] In this embodiment, specifically, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.45.

[0067] In this embodiment, specifically, the platinum catalyst includes hexachloroplatinic acid.

[0068] In this embodiment, specifically, the platinum catalyst accounts for 15% of the mass of the triethoxysilane.

[0069] Specifically, the preparation method of the two-component hollow sealant comprises the following steps:

[0070] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 40°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0071] Preparation of component B: stirring a filler, a silane coupling agent, a catalyst and a molecular sieve at 40° C. to obtain component B;

[0072] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0073] In this embodiment, more specifically, the mass ratio of the component A to the component B is 10:1.

[0074] In this embodiment, more specifically, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.25.

[0075] In the present embodiment, more specifically, the mass ratio of the filler, the silane coupling agent, the catalyst and the molecular sieve is 35:14:0.9:9.7.

[0076] In this embodiment, more specifically, the stirring condition is 6000 rpm for 16 minutes.

[0077] Example 3

[0078] A two-component hollow sealant comprises the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0079] In this embodiment, specifically, the isocyanate includes diphenylmethane-4-4'-diisocyanate MDI.

[0080] In this embodiment, specifically, the filler includes kaolin.

[0081] In this embodiment, specifically, the plasticizer includes phthalate.

[0082] In this embodiment, specifically, the catalyst is tetramethylbutanediamine.

[0083] In this embodiment, specifically, the molecular sieve is 4A molecular sieve.

[0084] In this embodiment, specifically, the preparation method of the silane coupling agent comprises the following steps:

[0085] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 82° C. for 4 hours to obtain the silane coupling agent.

[0086] In this embodiment, specifically, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.34.

[0087] In this embodiment, specifically, the platinum catalyst includes chloroplatinic acid and hexachloroplatinic acid.

[0088] In this embodiment, specifically, the platinum catalyst accounts for 14% of the mass of the triethoxysilane.

[0089] Specifically, the preparation method of the two-component hollow sealant comprises the following steps:

[0090] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 42°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0091] Preparation of component B: Stirring filler, silane coupling agent, catalyst and molecular sieve at 42° C. to obtain component B;

[0092] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0093] In this embodiment, more specifically, the mass ratio of the component A to the component B is 9.5:1.

[0094] In this embodiment, more specifically, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.17.

[0095] In the present embodiment, more specifically, the mass ratio of the filler, the silane coupling agent, the catalyst and the molecular sieve is 28:12:0.8:8.

[0096] In this embodiment, more specifically, the stirring condition is 5500 rpm for 14 minutes.

[0097] Example 4

[0098] A two-component hollow sealant comprises the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0099] In this embodiment, specifically, the isocyanate includes diphenylmethane-4-4'-diisocyanate MDI.

[0100] In this embodiment, specifically, the filler includes calcium carbonate.

[0101] In this embodiment, specifically, the plasticizer includes phthalate.

[0102] In this embodiment, specifically, the catalyst is tetramethylbutanediamine.

[0103] In this embodiment, specifically, the molecular sieve is 4A molecular sieve.

[0104] In this embodiment, specifically, the preparation method of the silane coupling agent comprises the following steps:

[0105] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 85° C. for 5 hours to obtain the silane coupling agent.

[0106] In this embodiment, specifically, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.45.

[0107] In this embodiment, specifically, the platinum catalyst includes hexachloroplatinic acid.

[0108] In this embodiment, specifically, the platinum catalyst accounts for 15% of the mass of the triethoxysilane.

[0109] Specifically, the preparation method of the two-component hollow sealant comprises the following steps:

[0110] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 45°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0111] Preparation of component B: stirring a filler, a silane coupling agent, a catalyst and a molecular sieve at 45° C. to obtain component B;

[0112] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0113] In this embodiment, more specifically, the mass ratio of the component A to the component B is 10:1.

[0114] In this embodiment, more specifically, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.25.

[0115] In the present embodiment, more specifically, the mass ratio of the filler, the silane coupling agent, the catalyst and the molecular sieve is 35:14:0.9:9.7.

[0116] In this embodiment, more specifically, the stirring condition is 6000 rpm for 16 minutes.

[0117] Example 5

[0118] A two-component hollow sealant comprises the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

[0119] In this embodiment, specifically, the isocyanate includes diphenylmethane-4-4'-diisocyanate MDI.

[0120] In this embodiment, specifically, the filler includes kaolin.

[0121] In this embodiment, specifically, the plasticizer includes phthalate.

[0122] In this embodiment, specifically, the catalyst is triethylenediamine.

[0123] In this embodiment, specifically, the molecular sieve is 4A molecular sieve.

[0124] In this embodiment, specifically, the preparation method of the silane coupling agent comprises the following steps:

[0125] Weigh triethoxysilane and N-aminoethylpiperazine, stir N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropwise add triethoxysilane, and react at 85° C. for 5 hours to obtain the silane coupling agent.

[0126] In this embodiment, specifically, the molar ratio of triethoxysilane to N-aminoethylpiperazine is 1:1.45.

[0127] In this embodiment, specifically, the platinum catalyst includes chloroplatinic acid and hexachloroplatinic acid.

[0128] In this embodiment, specifically, the platinum catalyst accounts for 15% of the mass of the triethoxysilane.

[0129] Specifically, the preparation method of the two-component hollow sealant comprises the following steps:

[0130] Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 45°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A;

[0131] Preparation of component B: stirring a filler, a silane coupling agent, a catalyst and a molecular sieve at 45° C. to obtain component B;

[0132] The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

[0133] In this embodiment, more specifically, the mass ratio of the A component to the B component is 9:1.

[0134] In this embodiment, more specifically, the molar ratio of the polycyclopropane diol to the isocyanate is 1:1.14.

[0135] In the present embodiment, more specifically, the mass ratio of the filler, the silane coupling agent, the catalyst and the molecular sieve is 23:11:0.7:9.7.

[0136] In this embodiment, more specifically, the stirring condition is 4500 rpm for 16 minutes.

[0137] Comparative Example 1

[0138] A two-component sealant, which differs from Example 1 in that polycyclopropane diol is replaced by polyether diol N204.

[0139] Comparative Example 2

[0140] A two-component sealant, which differs from Example 2 in that the filler is carbon black and no molecular sieve is added.

[0141] Comparative Example 3

[0142] A two-component sealant, which differs from Example 3 in that the coupling agent is not modified.

[0143] After the sealants of the above-mentioned embodiments and comparative examples are successfully configured and mixed according to the preparation method, the obtained sealants are subjected to relevant performance tests.

[0144] Weather resistance: The sealant specimens were subjected to xenon lamp aging test, and their appearance changes at different aging times were recorded.

[0145] Surface drying time: According to the method in standard GB / T 13477.5-2002, apply a proper amount of sealant on a clean glass plate at (25±2)℃ and relative humidity (55±5)% with a thickness of about 2mm. Touch the surface of the sealant with your finger every 1 minute until it is no longer sticky. This is the surface drying time.

[0146] Hardness: According to the method in standard GB / T 531.1-2008, use Shore A hardness tester to measure, press the Shore A hardness tester needle into the sealant sample at no less than 3 positions, and read the hardness value by converting the depth of pressure.

[0147] Tensile properties: refer to the method of standard GB / T 528-2009, use a tensile testing machine to measure, use type I dumbbell-shaped specimens, stretch at a speed of (500±50)mm / min at 21-25℃, and record the tensile strength and elongation at break.

[0148] Table 1 Sealant performance test of each embodiment and comparative example

[0149]

[0150] From the results in Table 1, it can be seen that when the polycyclopropane diol in component A is replaced by polyether polyol, or the filler is changed to carbon black and no molecular sieve is added, the final sealant has shown powdering phenomenon and is accompanied by cracking; at the same time, when the silane coupling agent is not modified, the tensile strength and elongation at break of the sealant also decrease significantly. This may be due to the reaction of the active groups in the silane coupling agent with the resin in component A to enhance the cross-linking effect and form a good dense cross-linking structure.

[0151] The invention provides a two-component hollow sealant, comprising the following ingredients: component A: polycyclopropane diol, isocyanate, filler, plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve; alkoxy chains with surface activity are introduced into triethoxy hydrogen silicon by hydrosilylation method to prepare a new silane coupling agent carrying active groups, the surface tension of which has excellent surface activity and can react better with a polyurethane system, so that the obtained sealant has good weather resistance and greatly improved tensile strength.

[0152] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A two-component hollow sealant, characterized in that: The invention comprises the following components: component A: polycyclopropane diol, isocyanate, filler and plasticizer; component B: filler, silane coupling agent, catalyst and molecular sieve.

2. The two-component hollow sealant according to claim 1, characterized in that: The silane coupling agent is prepared by the reaction of triethoxysilane, N-aminoethylpiperazine and a platinum catalyst.

3. The two-component hollow sealant according to claim 1, characterized in that: The isocyanate includes at least one of toluene diisocyanate TDI and diphenylmethane-4-4'-diisocyanate MDI.

4. The two-component hollow sealant according to claim 2, characterized in that: The preparation method of the silane coupling agent comprises the following steps: weighing triethoxysilane and N-aminoethylpiperazine, stirring N-aminoethylpiperazine and a platinum catalyst under gas protection, gradually dropping triethoxysilane, reacting at 80-85° C. for 3-5 hours, and obtaining the silane coupling agent.

5. The two-component hollow sealant according to claim 2, characterized in that: The molar ratio of the triethoxysilane to N-aminoethylpiperazine is 1:1.27-1.

45.

6. A method for preparing a two-component hollow sealant according to any one of claims 1 to 5, characterized in that: The following steps are involved: Preparation of component A: stirring polycyclopropane diol, isocyanate, filler and plasticizer at 40-45°C, then heating to 85°C for reaction, adding a catalyst, and reacting to obtain component A; Preparation of component B: Stirring filler, silane coupling agent, catalyst and molecular sieve at 40-45° C. to obtain component B; The prepared component A and component B are filled in proportion, glued using a glue dispenser, and statically mixed to obtain the two-component hollow sealant.

7. The method for preparing the two-component hollow sealant according to claim 6, characterized in that: The mass ratio of component A to component B is 9-10:

1.

8. The method for preparing a two-component hollow sealant according to claim 6, characterized in that: The molar ratio of the polycyclopropane diol to the isocyanate is 1:1.14-1.

25.

9. The method for preparing a two-component hollow sealant according to claim 6, characterized in that: The mass ratio of filler, silane coupling agent, catalyst and molecular sieve is 23-35:11-14:0.7-0.9:6.3-9.

7.

10. The method for preparing a two-component hollow sealant according to claim 6, characterized in that: The stirring condition is 4500-6000 rpm, and the stirring time is 12-16 min.

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