Low-water-permeability polyurethane sealant as well as preparation method and application thereof

Abstract

The invention provides a low-water-permeability polyurethane sealant as well as a preparation method and application thereof, and belongs to the technical field of sealants. The low-water-permeability polyurethane sealant comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: (1-1.2); the component A is prepared from the following raw materials in parts by weight: 100 to 150 parts of hydroxyl-terminated polyolefin polymer, 10 to 30 parts of diisocyanate, 80 to 150 parts of reinforcing agent, 5 to 15 parts of plasticizer and 5 to 10 parts of silane coupling agent; the component B is prepared from the following raw materials in parts by weight: 100 to 150 parts of hydroxyl-terminated polyolefin polymer, 5 to 20 parts of epoxy resin, 80 to 150 parts of reinforcing agent, 5 to 15 parts of plasticizer, 0.1 to 0.8 part of catalyst and 0.5 to 2 parts of anti-aging agent. The low-water-permeability polyurethane sealant has excellent water resistance, mechanical property, adhesive property and damp-heat aging resistance, and can be used for packaging and sealing a frame of a solar photovoltaic module laminated piece and bonding and sealing the bottom of a junction box.

Description

Technical Field

[0001] The invention relates to a low water permeability polyurethane sealant, a preparation method and application thereof. Background Art

[0002] With the development of the photovoltaic industry, especially the solar photovoltaic industry, the demand for the installation of offshore photovoltaic systems has increased, and the water vapor sensitivity of new battery technologies has placed higher and higher requirements on the water barrier properties of photovoltaic module sealants.

[0003] Silicone sealant is a commonly used sealant. Since the molecular structure of silicone sealant contains a large number of silicon-oxygen bonds (Si-O), silicone sealant has good elasticity and high and low temperature resistance. However, the molecular gap of this structure is large, which makes it easy for water molecules to penetrate. In addition, the cross-linking density of this structure is relatively low, which means that there are fewer connection points between its molecular chains, making the network structure formed inside the system loose and the water vapor permeability high. Therefore, it cannot meet the demand for water-blocking encapsulation at the edge of new components. Summary of the invention

[0004] In view of this, the present invention provides a low water permeability polyurethane sealant, a preparation method and an application thereof. The polyurethane water-blocking sealant has a low water vapor permeability and can meet the demand for water-blocking packaging at the edge of a new component.

[0005] The first aspect of the present invention provides a low water permeability polyurethane sealant for photovoltaic modules, comprising a component A and a component B, wherein the mass ratio of the component A to the component B is 1:(1-1.2);

[0006] The raw materials of component A include, by weight: 100-150 parts by weight of terminal hydroxyl polyolefin polymer; 10-30 parts by weight of diisocyanate; 80-150 parts by weight of reinforcing agent; 5-15 parts by weight of plasticizer; and 5-10 parts by weight of silane coupling agent; the raw materials of component B include, by weight: 100-150 parts by weight of terminal hydroxyl polyolefin polymer; 5-20 parts by weight of epoxy resin; 80-150 parts by weight of reinforcing agent; 5-15 parts by weight of plasticizer; 0.1-0.8 parts by weight of catalyst; and 0.5-2 parts by weight of anti-aging agent.

[0007] As an embodiment of the first aspect of the present invention, the terminal hydroxyl polyolefin polymer is selected from one or more of terminal hydroxyl polybutadiene, terminal hydroxyl hydrogenated polybutadiene, terminal hydroxyl styrene butadiene liquid rubber, terminal hydroxyl polyisobutylene, terminal hydroxyl polybutadiene-acrylonitrile, terminal hydroxyl polyisoprene and terminal hydroxyl hydrogenated polyisoprene.

[0008] As an embodiment of the first aspect of the present invention, the diisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate and dicyclohexylmethane-4,4'-diisocyanate.

[0009] As an embodiment of the first aspect of the present invention, the reinforcing agent is selected from one or more of calcium carbonate, carbon black, silica powder, heavy calcium, fumed silica, titanium dioxide powder, silicon aluminum carbon black and barium sulfate.

[0010] As an embodiment of the first aspect of the present invention, the plasticizer is selected from one or two of polydimethylsiloxane, paraffin oil and castor oil.

[0011] As an embodiment of the first aspect of the present invention, the silane coupling agent is selected from one or more of γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane and hexadecyltriethoxysilane.

[0012] As an embodiment of the first aspect of the present invention, the viscosity of the epoxy resin is in the range of 5000-32000 mPa·s.

[0013] As an embodiment of the first aspect of the present invention, the catalyst is selected from one or more of stannous octoate, dibutyltin dilaurate, bismuth carboxylate, potassium carboxylate, a chelate product of tetraethyl silicate and bis(acetyloxy)dibutyltin alkane, and di-n-butylbis(acetylacetonato)tin.

[0014] As an embodiment of the first aspect of the present invention, the anti-aging agent is selected from one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0015] The present invention also provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0016] A component A and a component B are provided, wherein the raw materials of the component A include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 10-30 parts by weight of a diisocyanate; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; and 5-10 parts by weight of a silane coupling agent; the raw materials of the component B include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 5-20 parts by weight of an epoxy resin; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; 0.1-0.8 parts by weight of a catalyst; and 0.5-2 parts by weight of an anti-aging agent;

[0017] The component A and the component B are mixed in a mass ratio of 1:(1-1.2) to obtain a polyurethane water-blocking sealant.

[0018] As an embodiment of the second aspect, the preparation method of component A includes:

[0019] Mixing 100-150 parts by weight of the hydroxyl-terminated polyolefin polymer and 10-30 parts by weight of the diisocyanate, reacting and curing to obtain a prepolymer;

[0020] Then, 80-150 parts by weight of the reinforcing agent, 5-15 parts by weight of the plasticizer, and 5-10 parts by weight of the silane coupling agent are added to the prepolymer and stirred to obtain component A.

[0021] As an embodiment of the second aspect, the raw materials of 100-150 parts by weight of the hydroxyl-terminated polyolefin polymer and 10-30 parts by weight of the diisocyanate are mixed, reacted and cured to obtain a prepolymer, comprising:

[0022] Add the hydroxyl-terminated polyolefin polymer into a reactor, heat to 90-120° C., vacuum dehydrate for 2-5 hours, and cool to room temperature under nitrogen or inert gas atmosphere;

[0023] Add diisocyanate to the reactor, heat it up under stirring, react at 60-100° C. for 2-6 hours, and cool it to room temperature to obtain a system containing a prepolymer;

[0024] The reinforcing agent, the plasticizer and the silane coupling agent are continuously added into the system and stirred to obtain the component A.

[0025] The low water permeability polyurethane sealant provided by the embodiment of the present invention uses a polyol with hydrophobic properties to construct the soft segment part in the polyurethane molecular chain. The polyol with hydrophobic properties is a longer polymer chain, and the chain segments form a relatively loose network structure inside the material. When these segments are hydrophobic, they can effectively prevent the penetration of water molecules, so that the prepared polyurethane sealant has excellent water-blocking properties. Secondly, the mechanical properties of the sealant can be significantly enhanced by adopting the polyurethane cross-linking curing method. In addition, a variety of silane coupling agents are also used in the formula to enhance the bonding force of the organic and inorganic interfaces, which can greatly improve the water-blocking performance. Therefore, the low water permeability polyurethane sealant of the present invention not only has a low water vapor permeability, but also has good adhesion, mechanical properties and resistance to moisture and heat aging. DETAILED DESCRIPTION

[0026] The technology for obtaining the low water permeability polyurethane sealant of the present invention and the preparation method are described below.

[0027] The first aspect of the embodiment of the present invention provides a polyurethane water-blocking sealant, which includes a component A and a component B, and the mass ratio of component A to component B is 1:(1-1.2).

[0028] The raw materials of component A include, by weight, 100-150 parts by weight of hydroxyl-terminated polyolefin polymer, 10-30 parts by weight of diisocyanate, 80-150 parts by weight of reinforcing agent, 5-15 parts by weight of plasticizer, and 5-10 parts by weight of silane coupling agent.

[0029] The raw materials of component B include, by weight: 100-150 parts by weight of hydroxyl-terminated polyolefin polymer, 5-20 parts by weight of epoxy resin, 80-150 parts by weight of reinforcing agent, 5-15 parts by weight of plasticizer, 0.1-0.8 parts by weight of catalyst, and 0.5-2 parts by weight of anti-aging agent.

[0030] The components for preparing the low water permeability polyurethane sealant in the embodiment of the present invention are divided into two groups. The two groups have different raw material components and proportions. After the raw materials of each component are combined, the molecular weight produced is larger, and a sealant with better mechanical properties can be obtained.

[0031] The principle of separate design of component A and component B is explained below.

[0032] The diisocyanate in component A contains two isocyanate groups (-NCO groups), so that one -NCO group in the diisocyanate reacts with the hydroxyl-OH of the hydroxyl-terminated polyolefin polymer in component A to generate a polyurethane prepolymer. When component A is mixed with component B, another -NCO group in the diisocyanate can further react with the hydroxyl-terminated polyolefin polymer in component B to generate a polymer with a large molecular weight, thereby obtaining a sealant with good mechanical properties. In the embodiment of the present invention, a part of the hydroxyl-terminated polyolefin polymer is pre-reacted with the diisocyanate first, mainly to control the reaction rate between the two, so as to avoid that the isocyanate-NCO groups all react with the hydroxyl-terminated polyolefin polymer to form a polymer with a local molecular weight that is too large, and chain extension can no longer be performed, resulting in a decrease in the mechanical properties of the sealant. Therefore, the hydroxyl-terminated polyolefin polymer is designed in components A and B, and the hydroxyl-terminated polyolefin polymer in component A is pre-reacted with one -NCO group of the isocyanate group first. When component A is mixed with component B, the remaining -NCO group of the diisocyanate reacts with the terminal hydroxyl polyolefin polymer in component B to extend the molecular chain and ensure the mechanical properties of the sealant.

[0033] In addition, in the embodiments of the present invention, in order to reduce the viscosity of the system and increase the extrusion speed, the extrusion speed can be effectively increased by adding a plasticizer to component A and component B. In order to make the mass ratio of component A and component B 1: (1-1.2) at the same extrusion volume, a reinforcing agent is added to components A and B respectively in the embodiments of the present application. In addition, by adding a reinforcing agent, the impact resistance and fracture toughness of the material can be improved, and the mechanical strength of the sealant, such as tensile strength, compressive strength, etc., can be increased, making the material more durable.

[0034] The catalyst in component B plays a role in catalyzing the polymerization rate of isocyanate. In component A, the degree of polymerization of the hydroxyl-terminated polyolefin polymer and diisocyanate needs to be controlled, so the catalyst needs to be separated from the diisocyanate, and the catalyst is therefore placed in component B. Since the catalyst also catalyzes the polymerization reaction of the silane coupling agent, the silane coupling agent is not added to component B.

[0035] In addition, the antioxidant and epoxy resin in component B contain active groups, which are easy to react with the isocyanate groups in component A. Therefore, the epoxy resin and antioxidant in component B cannot be put into component A. Instead, the epoxy resin in component B is mixed after the pre-reaction of the substances in component A, which can further react with the isocyanate groups in component A to increase the cross-linking density. This ensures that the low water permeability polyurethane sealant develops in the direction of demand, giving it unexpected waterproof properties, mechanical properties, and anti-wet heat aging properties.

[0036] The low water permeability polyurethane sealant according to the embodiment of the present invention has simple components, and the ratio and composition of these components can significantly improve the water barrier performance and mechanical properties of the sealant. It not only has a low water vapor permeability, but also has good adhesion, mechanical properties and resistance to moisture and heat aging, and can fully meet the edge water vapor barrier packaging requirements of new components in the photovoltaic industry.

[0037] The low water permeability polyurethane sealant of the embodiment of the present invention can be used in the photovoltaic field, such as sealing the edge of a photovoltaic module. In addition, it can also be used in the automotive field, the electronic equipment field, or the transportation engineering and water conservancy engineering fields, which are not limited in the embodiment of the present invention.

[0038] In one embodiment of the present invention, the hydroxyl-terminated polyolefin polymer is selected from one or more of hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated styrene butadiene liquid rubber, hydroxyl-terminated polyisobutylene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated polyisoprene and hydroxyl-terminated hydrogenated polyisoprene. These substances have high molecular crystallinity, saturated molecular chains, low molecular chain polarity, excellent hydrolysis stability and water resistance, and are conducive to improving the water-blocking performance of the sealant.

[0039] In one embodiment of the present invention, the diisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate and dicyclohexylmethane-4,4'-diisocyanate.

[0040] In one embodiment of the present invention, the reinforcing agent is selected from one or more of calcium carbonate, carbon black, silica powder, heavy calcium, fumed silica, titanium dioxide powder, silicon aluminum carbon black and barium sulfate.

[0041] In one embodiment of the present invention, the plasticizer is selected from one or two of polydimethylsiloxane, paraffin oil and castor oil.

[0042] In one embodiment of the present invention, the silane coupling agent is selected from one or more of γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane and hexadecyltriethoxysilane.

[0043] In one embodiment of the present invention, the viscosity of the epoxy resin is in the range of 5000-32000 mPa·s.

[0044] In one embodiment of the present invention, the catalyst is selected from one or more of stannous octoate, dibutyltin dilaurate, bismuth carboxylate, potassium carboxylate, a chelate product of tetraethyl silicate and bis(acetyloxy)dibutyltin alkane, and di-n-butylbis(acetylacetonato)tin.

[0045] In one embodiment of the present invention, the anti-aging agent is selected from one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0046] The present invention also provides a method for preparing a polyurethane water-blocking sealant, which can be used to prepare the polyurethane water-blocking sealant described in the above embodiment.

[0047] The following is a description of the preparation method of the polyurethane water-blocking sealant according to the embodiment of the present application.

[0048] The preparation method of the polyurethane water-blocking sealant according to the embodiment of the present invention comprises:

[0049] S10, providing component A and component B, wherein the raw materials of component A include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 10-30 parts by weight of a diisocyanate; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; and 5-10 parts by weight of a silane coupling agent; the raw materials of component B include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 5-20 parts by weight of an epoxy resin; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; 0.1-0.8 parts by weight of a catalyst; and 0.5-2 parts by weight of an anti-aging agent;

[0050] S20, mixing component A and component B in a mass ratio of 1:(1-1.2) to obtain a low water permeability polyurethane sealant.

[0051] The preparation method of the embodiment of the present invention, when prepared according to the above components and ratios, is conducive to the reaction of diisocyanate and hydroxyl-containing polyolefin polymer to form a prepolymer, and then further generate a polymer with a large molecular weight, so that the obtained polyurethane water-blocking sealant has a low water vapor permeability, and also has good adhesion, mechanical properties and resistance to moisture and heat aging.

[0052] In one embodiment of the present invention, the preparation method of component A comprises: mixing 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer and 10-30 parts by weight of a diisocyanate, reacting and curing to obtain a prepolymer, and then adding 80-150 parts by weight of a reinforcing agent, 5-15 parts by weight of a plasticizer, and 5-10 parts by weight of a silane coupling agent to the prepolymer, stirring to obtain component A.

[0053] By adopting a grouping method, the terminal hydroxyl polyolefin polymer in component A and diisocyanate are first reacted to form a prepolymer. Then other plasticizers are added to reduce the viscosity of the system and increase the extrusion speed. In addition, by adding reinforcing agents and silane coupling agents, the product's bonding strength, machine strength, impact resistance, fracture toughness and other properties can be greatly improved.

[0054] In one embodiment of the present invention, 100-150 parts by weight of a terminal hydroxyl polyolefin polymer and 10-30 parts by weight of a diisocyanate are mixed and reacted to obtain a prepolymer, including: adding the terminal hydroxyl polyolefin polymer to a reactor, heating to 90-120°C, vacuum dehydrating for 2-5 hours, and cooling to room temperature under nitrogen or inert gas atmosphere. Add diisocyanate to the reactor, heat it up under stirring, react at 60-100°C for 2-6 hours, and cool it to room temperature to obtain a system containing a prepolymer; continue to add a reinforcing agent, a plasticizer, and a silane coupling agent to the system, stir, and obtain component A. This method can ensure the stability and sufficiency of the chain extension reaction of the prepolymer.

[0055] The low water permeability polyurethane sealant of the embodiment of the present invention can be applied to photovoltaic modules, for example, it can be applied to the frame encapsulation seal of the laminate of the solar photovoltaic module and the bonding seal of the bottom of the junction box. In addition, it can also be applied to the automotive field, the electronic equipment field, or the transportation engineering, water conservancy engineering field, etc., and the present invention is not limited to this.

[0056] The preparation method of the low water permeability polyurethane sealant is further described below through specific examples.

[0057] Example 1

[0058] Embodiment 1 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0059] 1) Component A: 100 g of hydroxy-terminated polybutadiene was added to a reaction kettle, heated to 90° C., vacuum-dehydrated with an oil pump for 5 h, then cooled to room temperature in a nitrogen atmosphere, 10 g of toluene diisocyanate (TDI) was added thereto, heated at 60° C. for 6 h under stirring, and cooled to room temperature; 8 g of paraffin oil and 5 g of isopropyltrimethoxysilane were added to the system, and mixed evenly; 70 g of dry nano-calcium carbonate and 10 g of dry silicon powder were added to the above mixture, and stirred evenly to obtain component A;

[0060] 2) Component B: 100 g of hydroxy-terminated polybutadiene, 15 g of epoxy resin with a viscosity of 5000-6000 mPa·s, 8 g of paraffin oil, 0.1 g of stannous octoate and 0.5 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are mixed uniformly; 70 g of nano calcium carbonate, 10 g of silicon powder and 2 g of nano carbon black are added thereto, and the mixture is stirred uniformly to obtain component B;

[0061] 3) The above component A and component B are fully mixed in a mass ratio of 1:1 to obtain a low water permeability polyurethane sealant.

[0062] Example 2

[0063] Embodiment 2 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0064] 1) Component A: 100 g of terminal hydroxyl hydrogenated polybutadiene was added to a reaction kettle, heated to 90°C, vacuum-dehydrated with an oil pump for 5 h, then cooled to room temperature in a nitrogen atmosphere, 15 g of diphenylmethane diisocyanate (MDI) was added thereto, heated at 60°C for 6 h under stirring, and cooled to room temperature; 8 g of paraffin oil and 5 g of isopropyltrimethoxysilane were added to the system and mixed evenly; 70 g of dry nano calcium carbonate and 10 g of dry heavy calcium carbonate were added to the above mixture, and stirred evenly to obtain component A;

[0065] 2) Component B: 100 g of hydroxy-terminated hydrogenated polybutadiene, 15 g of epoxy resin with a viscosity of 5000-6000 mPa·s, 8 g of paraffin oil, 0.1 g of stannous octoate and 0.5 g of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid were mixed uniformly; 70 g of nano calcium carbonate, 10 g of heavy calcium carbonate and 2 g of nano carbon black were added thereto, and the mixture was stirred uniformly to obtain component B;

[0066] 3) The above component A and component B are fully mixed in a mass ratio of 1:1 to obtain a low water permeability polyurethane sealant.

[0067] Example 3

[0068] Embodiment 3 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0069] 1) Component A: 120 g of hydroxy-terminated butadiene styrene liquid rubber is added to a reaction kettle, heated to 120° C., vacuum-dehydrated with an oil pump for 2 h, then cooled to room temperature in a nitrogen atmosphere, 20 g of isophorone diisocyanate (IPDI) is added thereto, heated at 100° C. for 3 h under stirring, and cooled to room temperature; 5 g of polydimethylsiloxane and 10 g of dodecyltrimethoxysilane are added to the system, and mixed evenly; 80 g of dry nano-calcium carbonate and 10 g of dry titanium dioxide powder are added to the above mixture, and stirred evenly to obtain component A;

[0070] 2) Component B: 100 g of hydroxy-terminated styrene butadiene liquid rubber, 20 g of epoxy resin with a viscosity of 6000-10000 mPa·s, 5 g of polydimethylsiloxane, 0.2 g of dibutyltin dilaurate and 0.5 g of 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane were mixed uniformly; 80 g of nano calcium carbonate, 10 g of titanium dioxide powder and 2 g of nano carbon black were added thereto, and the mixture was stirred uniformly to obtain component B;

[0071] 3) The above component A and component B are fully mixed in a mass ratio of 1:1.2 to obtain a low water permeability polyurethane sealant.

[0072] Example 4

[0073] Embodiment 4 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0074] 1) Component A: 150g of hydroxy-terminated polyisobutylene was added to a reaction kettle, heated to 120°C, and vacuum-dehydrated with an oil pump for 2h, then cooled to room temperature in a nitrogen atmosphere, 25g of hexamethylene diisocyanate (HDI) was added thereto, heated at 90°C under stirring, reacted for 5h, and cooled to room temperature; 10g of polydimethylsiloxane and 5g of dodecyltriethoxysilane were added to the system, and mixed evenly; 90g of dry nano calcium carbonate and 10g of dry heavy calcium carbonate were added to the above mixture, and stirred evenly to obtain component A;

[0075] 2) Component B: 150 g of hydroxy-terminated polyisobutylene, 15 g of epoxy resin with a viscosity of 10000-16000 mPa·s, 10 g of polydimethylsiloxane, 0.5 g of bismuth carboxylate and 0.5 g of 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene are mixed uniformly; 120 g of nano calcium carbonate, 10 g of heavy calcium and 2 g of nano carbon black are added thereto, and the mixture is stirred uniformly to obtain component B;

[0076] 3) The above component A and component B are fully mixed in a mass ratio of 1:1.2 to obtain a low water permeability polyurethane sealant.

[0077] Example 5

[0078] Embodiment 5 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0079] 1) Component A: 140 g of hydroxy-terminated polybutadiene-acrylonitrile was added to a reaction kettle, heated to 120° C., vacuum-dehydrated with an oil pump for 2 h, then cooled to room temperature in a nitrogen atmosphere, 15 g of TDI was added thereto, heated under stirring, reacted at 90° C. for 5 h, and cooled to room temperature; 10 g of polydimethylsiloxane and 5 g of isobutyltrimethoxysilane were added to the system, and mixed evenly; 100 g of dry nano-calcium carbonate and 10 g of dry silicon micropowder were added to the above mixture, and stirred evenly to obtain component A;

[0080] 2) Component B: 130 g of hydroxy-terminated polybutadiene-acrylonitrile, 5 g of epoxy resin with a viscosity of 20,000-32,000 mPa·s, 10 g of polydimethylsiloxane, 0.5 g of potassium carboxylate and 0.5 g of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate are mixed evenly; 130 g of nano calcium carbonate, 18 g of silicon powder and 2 g of nano carbon black are added thereto, and the mixture is stirred evenly to obtain component B;

[0081] 3) The above component A and component B are fully mixed in a mass ratio of 1:1 to obtain a low water permeability polyurethane sealant.

[0082] Example 6

[0083] Embodiment 6 provides a method for preparing a low water permeability polyurethane sealant, comprising:

[0084] 1) Component A: 130 g of hydroxy-terminated polyisoprene was added to a reaction kettle, heated to 120° C., vacuum-dehydrated with an oil pump for 2 h, then cooled to room temperature in a nitrogen atmosphere, 15 g of MDI was added thereto, heated at 90° C. for 5 h under stirring, and cooled to room temperature; 15 g of paraffin oil and 5 g of hexadecyltrimethoxysilane were added to the system, and mixed evenly; 90 g of dry nano-calcium carbonate and 10 g of dry fumed silica were added to the above mixture, and stirred evenly to obtain component A;

[0085] 2) Component B: 150 g of hydroxy-terminated polyisoprene, 10 g of epoxy resin with a viscosity of 16000-20000 mPa·s, 10 g of paraffin oil, 0.1 g of di-n-butyl bis(acetylacetonato)tin and 1 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are mixed evenly; a mixture of 90 g of nano-calcium carbonate, 10 g of fumed silica and 2 g of nano-carbon black is added thereto, and the mixture is stirred evenly to obtain component B;

[0086] 3) The above component A and component B are fully mixed in a mass ratio of 1:1 to obtain a low water permeability polyurethane sealant.

[0087] Example 7

[0088] Embodiment 7 provides a method for preparing a polyurethane water-blocking sealant, comprising:

[0089] 1) Component A: 120 g of hydroxy-terminated hydrogenated polyisoprene was added to a reaction kettle, heated to 120° C., vacuum-dehydrated with an oil pump for 2 h, then cooled to room temperature in a nitrogen atmosphere, 15 g of MDI was added thereto, heated at 90° C. for 5 h under stirring, and cooled to room temperature; 8 g of paraffin oil and 5 g of γ-glycidyloxypropyltrimethoxysilane were added to the system, and mixed evenly; 90 g of dry nano-calcium carbonate and 10 g of dry fumed silica were added to the above mixture, and stirred evenly to obtain component A;

[0090] 2) Component B: 130 g of hydroxy-terminated hydrogenated polyisoprene, 10 g of epoxy resin having a viscosity of 16000-20000 mPa·s, 15 g of paraffin oil, 0.1 g of di-n-butyl bis(acetylacetonato)tin and 1 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] were mixed evenly; a mixture of 90 g of nano-calcium carbonate, 10 g of fumed silica and 2 g of nano-carbon black was added thereto, and the mixture was stirred evenly to obtain component B;

[0091] 3) The above component A and component B are fully mixed in a mass ratio of 1:1 to obtain a low water permeability polyurethane sealant.

[0092] The test method and test results of the polyurethane water-blocking sealant obtained in the above embodiment are described below.

[0093] The tensile strength and elongation at break were tested according to the test method described in GB / T 528-2009; the water vapor transmission rate was tested according to the test method in GB / T30412-2013. The polyurethane water-blocking sealants provided in Examples 1-7 were tested for various properties, and the existing silicone sealant was tested as a comparative example (the comparative example was tested under the same test conditions as the product of the embodiment of the present invention), and the specific test results are shown in Table 1.

[0094] Table 1 Comparison of performance test results

[0095]

[0096]

[0097] As can be seen from Table 1, the various properties of the seven embodiments corresponding to the low water permeability polyurethane sealant of the embodiment of the present invention are compared with the silicone sealant of the comparative example. Conventional performance: the tensile strength of the low water permeability polyurethane sealant of the embodiment of the present invention is above 2.5MPa, and the highest can reach 3.67MPa, which is much higher than the tensile strength of the silicone sealant of the comparative example of 2.23MPa; the elongation at break of the sealant of the present invention is above 377%, and the highest can reach 564%, which is much higher than 341% of the comparative example, and the water vapor permeability of the sealant of the present invention is below 4g / m2 / d, and the lowest is 1.89g / m2 / d, which is much lower than the water vapor permeability of the comparative example of 49.76g / m2 / d, indicating that the low water permeability polyurethane sealant of the embodiment of the present invention has a very good water blocking effect. In addition, the aging performance also shows good tensile strength, elongation at break, and low water vapor permeability.

[0098] The above are some specific embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, they can make several changes, improvements and modifications. The technical solutions after these changes, improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A low water permeability polyurethane sealant, characterized in that: Comprising component A and component B, wherein the mass ratio of component A to component B is 1:(1-1.2); The raw materials of component A include, by weight: 100-150 parts by weight of hydroxyl-terminated polyolefin polymer; 10-30 parts by weight of diisocyanate; 80-150 parts by weight of reinforcing agent; 5-15 parts by weight of plasticizer; and Silane coupling agent 5-10 parts by weight; The raw materials of the B component include, by weight: 100-150 parts by weight of hydroxyl-terminated polyolefin polymer; Epoxy resin 5-20 parts by weight; 80-150 parts by weight of reinforcing agent; 5-15 parts by weight of plasticizer; 0.1-0.8 parts by weight of catalyst; and Anti-aging agent 0.5-2 parts by weight.

2. The low water permeability polyurethane sealant according to claim 1, characterized in that: The hydroxyl-terminated polyolefin polymer is selected from one or more of hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated styrene butadiene liquid rubber, hydroxyl-terminated polyisobutylene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated polyisoprene and hydroxyl-terminated hydrogenated polyisoprene; and / or, The diisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and dicyclohexylmethane-4,4'-diisocyanate.

3. The low water permeability polyurethane sealant according to claim 1 or 2, characterized in that: The reinforcing agent is selected from one or more of calcium carbonate, carbon black, silicon powder, heavy calcium, fumed silica, titanium dioxide powder, silicon aluminum carbon black and barium sulfate; and / or, The plasticizer is selected from one or two of polydimethylsiloxane, paraffin oil and castor oil.

4. The low water permeability polyurethane sealant according to claim 1 or 2, characterized in that: The silane coupling agent is selected from one or more of γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane and hexadecyltriethoxysilane.

5. The low water permeability polyurethane sealant according to claim 1 or 2, characterized in that: The viscosity of the epoxy resin ranges from 5000 to 32000 mPa·s.

6. The low water permeability polyurethane sealant according to claim 1 or 2, characterized in that: The catalyst is selected from one or more of stannous octoate, dibutyltin dilaurate, bismuth carboxylate, potassium carboxylate, a chelate product of tetraethyl silicate and bis(acetyloxy)dibutyltin alkane, and di-n-butylbis(acetylacetonato)tin; and / or, The anti-aging agent is selected from one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

7. The method for preparing the low water permeability polyurethane sealant according to any one of claims 1 to 6, characterized in that: include: A component A and a component B are provided, wherein the raw materials of the component A include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 10-30 parts by weight of a diisocyanate; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; and 5-10 parts by weight of a silane coupling agent; the raw materials of the component B include, by weight: 100-150 parts by weight of a hydroxyl-terminated polyolefin polymer; 5-20 parts by weight of an epoxy resin; 80-150 parts by weight of a reinforcing agent; 5-15 parts by weight of a plasticizer; 0.1-0.8 parts by weight of a catalyst; and 0.5-2 parts by weight of an anti-aging agent; The component A and the component B are mixed in a mass ratio of 1:(1-1.2) to obtain a low water permeability polyurethane sealant.

8. The method for preparing the low water permeability polyurethane sealant according to claim 7, characterized in that: The preparation method of the A component comprises: Mixing 100-150 parts by weight of the hydroxyl-terminated polyolefin polymer and 10-30 parts by weight of the diisocyanate, reacting and curing to obtain a prepolymer; Then, 80-150 parts by weight of the reinforcing agent, 5-15 parts by weight of the plasticizer, and 5-10 parts by weight of the silane coupling agent are added to the prepolymer and stirred to obtain component A.

9. The method for preparing the low water permeability polyurethane sealant according to claim 8, characterized in that: The raw materials of 100-150 parts by weight of the terminal hydroxyl polyolefin polymer and 10-30 parts by weight of the diisocyanate are mixed, reacted and cured to obtain a prepolymer, including: Add the hydroxyl-terminated polyolefin polymer into a reactor, heat to 90-120° C., vacuum dehydrate for 2-5 hours, and cool to room temperature under nitrogen or inert gas atmosphere; Add diisocyanate to the reactor, heat it up under stirring, react at 60-100° C. for 2-6 hours, and cool it to room temperature to obtain a system containing a prepolymer; The reinforcing agent, the plasticizer and the silane coupling agent are continuously added into the system and stirred to obtain the component A.

10. Use of the low water permeability polyurethane sealant according to any one of claims 1 to 6 in photovoltaic modules.

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