CN116375965A - A flame-retardant polyurethane foam sealant and its preparation method - Google Patents

Abstract

The application discloses a flame-retardant polyurethane foam joint mixture and a preparation method thereof, and relates to the technical field of foam joint mixtures, wherein the flame-retardant polyurethane foam joint mixture comprises 20-40 parts of isocyanate, 20-35 parts of modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, 5-10 parts of nitrogen-containing heterocyclic polyester polyol, 10-20 parts of polyether polyol, 20-35 parts of chlorinated paraffin, 2-5 parts of foam stabilizer, 1-2 parts of catalyst, 15-20 parts of propellant, 3-4 parts of flame retardant, 0.5-1 part of anti-settling agent, and 1-3 parts of reinforcing agent and auxiliary anti-settling filler. The application has the effect of improving the flame retardant effect on the premise of ensuring the use effect and quality of the caulking agent.

Description

A flame-retardant polyurethane foam sealant and its preparation method

technical field

The present application relates to the technical field of foam sealants, in particular to a polyurethane foam sealant.

Background technique

Polyurethane foam caulking agent is a multi-purpose polyurethane foam filled elastic sealing material. It is a special polyurethane product filled with polyurethane prepolymer, foaming agent, catalyst and other components in a pressure-resistant aerosol can.

When in use, the aerosol colloid is sprayed to the site to be constructed through the matching sizing gun or manual nozzle, and the forming, foaming, bonding and sealing processes are completed in a short period of time. Its cured foam elastomer has excellent performances such as bonding, waterproof, thermal expansion and contraction resistance, heat insulation, and sound insulation. Some flame-retardant sealants also have flame-retardant effects, and are widely used in building door and window edge seams, and component expansion and contraction. Filling and sealing of seams and holes.

Since the fire resistance of buildings has gradually been paid attention to in recent years, the flame retardancy has also become an important reference performance of the sealant, and the relevant national policies also have clear requirements. The main molecular composition of polyurethane is generally carbon, hydrogen and nitrogen, and it is a flammable material. Most of the one-component polyurethane foam sealants have a fire rating of B3.

The commonly used method to improve the flame retardant performance of polyurethane foam sealants is to add flame retardants, among which the commonly used flame retardants are adding TCPP, TCEP and brominated flame retardant paraffin. This type of flame retardant phosphorus or bromine The content is higher, thereby achieving the flame retardant effect. However, too much phosphorus and bromine in it will easily hydrolyze the material structure to produce acid substances, destroy the silicone oil emulsification of the foaming agent, and damage the cell structure of the caulking agent, which will reduce the shelf life of the caulking agent and make the The shrinkage of the cured foam will not only cause the gap to be filled unrealistically, but will even deform the structure such as the window frame at the caulking place through the shrinkage force. Moreover, adding too much liquid flame retardant will reduce the effective content of polyurethane, and the hardness and density of the product cannot meet the requirements for use, so it is difficult to improve the fire protection level.

Another way to improve the flame retardant performance is to add solid flame retardants such as expanded graphite. After being heated to a certain extent, the expanded graphite will start to expand, and then form a porous carbonized layer with a certain thickness. With the thermal stability of the porous carbonized layer Separate the heat source, thereby alleviating the segmentation of the polymer, and theoretically can achieve the B1 flame retardant effect. However, in order to obtain the expansion and flame-retardant effect of expanded graphite, the particle size is generally not higher than 200 mesh, but in order not to affect the gun, the mesh number of the caulking agent is required to be no less than 1500 mesh, otherwise precipitation and gun blocking will occur. Therefore, the practicality will be greatly reduced.

Based on the above factors, a new way to improve the flame retardancy of polyurethane foam sealant is needed, which can improve the flame retardancy of the sealant while taking into account the use effect of the product.

Contents of the invention

In order to improve the defect that the existing method of improving the flame retardancy of polyurethane foam sealant will reduce the performance of the sealant, the application provides a flame-retardant polyurethane foam sealant and a production method.

A flame-retardant polyurethane foam sealant provided by the application adopts the following technical scheme:

A flame-retardant polyurethane foam caulking agent, which is composed of 20-40 parts of isocyanate, 20-35 parts of modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, 5-5 parts of nitrogen-containing heterocyclic polyester polyol 10 parts, 10-20 parts of polyether polyol, 20-35 parts of chlorinated paraffin, 2-5 parts of foam stabilizer, 1-2 parts of catalyst, 15-20 parts of propellant, 3-4 parts of flame retardant, 0.5-1 parts of settling agent, 1-3 parts of reinforcing agent and auxiliary anti-settling filler.

By adopting the above technical scheme, in the selection of the main material polyether polyol, a mixture of modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol and nitrogen-containing heterocyclic polyester polyol is added, which will burn when heated. A carbon foam layer is generated on the surface to insulate heat and oxygen, thereby improving the flame retardant effect. At the same time, through the composition ratio, the uniformity of the formed carbon foam layer is effectively improved, and the harmful gas and smoke generated are small. It is more suitable for indoor or building fireproof joints; the rigid structures such as heterocyclic rings and benzene rings can effectively improve the thermal stability of the joints, and can resist the acidity of phosphorus and oxygen bonds when they encounter water. The substance neutralizes the softening of the product and reduces the change in the properties of the product, so that the product can also have stable and good properties in high temperature and low temperature environments.

Through this ratio, in terms of the addition of flame retardants, the flame retardant effect of the product is not improved simply by adding flame retardants, but starting from polyether polyol and polyester polyol, the main raw materials of the caulking agent, by introducing The flame retardant element is used to improve the flame retardant effect of the main raw material of the filler, and the auxiliary flame retardant is added to jointly achieve the improvement of the flame retardant effect, and the flame retardant level is raised to above B2 level. The construction of the joint agent is cheap and the foam performance ensures the applicability of the polyurethane joint sealant and the storage stability of the product.

Optionally, the flame retardant is TCPP and antimony trioxide.

By adopting the above technical solution, on the basis of the flame retardancy of TCPP itself, the synergistic flame retardancy of antimony trioxide and long-chain chlorinated paraffin increases the foam support, and improves the thermal stability of the product through the long carbon chain.

Optionally, the anti-settling agent is fumed silica.

By adopting the above technical scheme, the anti-sedimentation agent can effectively increase the thixotropy while improving the use performance such as product hardness, and reduce the sedimentation of antimony trioxide, thereby increasing the amount of antimony trioxide added, and synergistically improving the antimony trioxide with chlorinated paraffin Flame retardant effect, the added amount is not more than 1 part, in order to reduce the occurrence of uneven mixing due to large swings in the viscosity of the caulking agent.

Optionally, antimony trioxide is pre-dried at 100-120° C. for more than 2 hours.

By adopting the above technical scheme, the antimony trioxide and meteorological silica are dried in advance, and the moisture content is controlled to a predetermined value before use, which effectively reduces the influence of moisture on the viscosity of the product and ensures the viscosity of the glue. Shaking before use can evenly disperse antimony trioxide in the foam system to ensure the uniformity of flame retardancy.

Optionally, the reinforcing agent is calcium carbonate, the auxiliary anti-settling filler is silicon micropowder, and both the reinforcing agent and the auxiliary anti-settling filler are above 1500 mesh.

By adopting the above technical scheme, the superfine calcium carbonate and silicon micropowder are in a suspended state in the packaging tank, and can be evenly dispersed in the liquid prepolymer with antimony trioxide and silicon dioxide, and part of the sedimentation material is also in a loose flocculent accumulation According to the requirements of conventional polyurethane foam sealants, it should be shaken more than 10 times before use, which is enough to fully mix the fillers in flame-retardant products to achieve uniform reinforcement, hardening and flame-retardant effects.

Optionally, the selected foam stabilizer is one or more of the products of Evonik Degussa, Zhongshan Dongjun, Hangzhou Chongyao, and Nanjing Mesid.

By adopting the above-mentioned technical solution, after testing, on the basis of the deployment of the flame-retardant solution, the foam using the above-mentioned brand foam stabilizer has more nucleation, finer cells, denser cells and better flame retardancy. In addition, dimensional stability is guaranteed.

Optionally, the isocyanate is polymethylene polyphenyl polyisocyanate, wherein the NCO mass fraction of PAPI is 30-32%.

By adopting the above-mentioned technical scheme, the selection of the specific type of isocyanate and the selection of the NCO mass fraction of PAPI can provide a stable reaction speed on the basis of moderate viscosity after mixing the raw materials within this range, and then improve the use effect of the product. At the same time, it improves the efficiency of putting products into the market.

Optionally, the modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture has a number average molecular weight of 300-3000, a functionality of 2-3, and a hydroxyl value of 30-300 mgKOH/g.

The number-average molecular weight of the nitrogen-containing heterocyclic polyester polyol is 300-3000, the functionality is 2-3, and the hydroxyl value is 30-300 mgKOH/g.

By adopting the above-mentioned technical scheme, the value selection of modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture and nitrogen-containing heterocyclic polyester polyol can be improved while improving product viscosity and performance after foaming. Its own reaction efficiency improves the quality of the caulking agent.

Optionally, the reinforcing agent and auxiliary anti-settling fillers are pre-dried at 100-120°C for more than 2 hours.

By adopting the above technical scheme, the drying treatment of the reinforcing agent and the auxiliary anti-settling filler reduces the moisture content to an appropriate level, and reduces the agglomeration of the reinforcing agent and the auxiliary anti-settling filler before input.

The application also provides a method for making a flame-retardant polyurethane foam sealant using the following technical scheme:

A preparation method of flame-retardant polyurethane foam sealant, comprising the sealant described in any one of claims 1-9, comprising the steps of:

S1. Modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, nitrogen-containing heterocyclic polyester polyol, polyether polyol, chlorinated paraffin, foam stabilizer, catalyst, flame retardant, anti-settling Agent, reinforcing agent and auxiliary anti-settling filler are stirred evenly to form a composite material;

S2, filling the combined material and the isocyanate into the pressure tank together;

S3. When sealing the valve port, use the aerosol filling equipment to fill the propellant into the pressure tank;

S4. Shake and mix evenly after covering, and it can be used normally after being placed at room temperature for a week.

By adopting the above-mentioned technical scheme, sealing and inflating after filling are carried out step by step. In the pressure tank, the combined material and isocyanate are evenly mixed and then reacted, which reduces the contact between the reacted substance and moisture in the air to ensure product viscosity and storage stability. The excessive isocyanate in the foam sprayed out during product construction fully contacts with the moisture in the air to react and solidify to form a stable and dense white micro-elastic foam, so as to achieve the functions of sealing, waterproofing and heat insulation.

In summary, the present application includes at least one of the following beneficial technical effects:

By reducing the addition of flame retardants, selectively adding modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixtures and nitrogen-containing heterocyclic polyester polyols to the main raw material polyether polyols, so that The main material has flame retardant elements, which can produce a carbonized layer when burning, and then block the heat source and air to achieve a flame retardant effect. At the same time, the flexible polyether chain segment of the macromolecule is used to balance the rigidity of the benzene ring and the nitrogen-containing heterocycle , so as to meet the dimensional stability of the product after high-temperature extrusion in summer and the toughness at low temperature in winter, and improve the flame retardancy and calorific value of the main chain segment itself, and raise the flame retardancy to B2 level;

Then add a small amount of flame retardant TCPP to assist flame retardant, add antimony trioxide and high-viscosity chlorinated paraffin as the main filler for synergistic flame retardancy, and add anti-sedimentation agent to effectively reduce the problem of uneven distribution of antimony trioxide and improve The effect of the use of caulking agent;

The selection of isocyanate, the selection of nitrogen-containing heterocyclic polyester polyol and the selection of phosphorus-containing, halogen-containing polyether polyol, and polyether polyol mixture containing benzene ring can improve the efficiency of product reaction on the basis of improving product viscosity performance.

Reinforcing agent and auxiliary anti-settling filler can not only achieve the effect of reinforcement and hardening, but also improve heat resistance. The more important thing is to evenly disperse the flame retardant to prevent the flame retardant from sticking to the bottom and shaking unevenly when it is used. Construction and flame retardant effect.

Detailed ways

The embodiment of the present application discloses a flame-retardant polyurethane foam caulking agent and a manufacturing method thereof.

The formula of the flame retardant polyurethane foam sealant includes 20-40 parts of isocyanate, 20-35 parts of modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, 5-10 parts of nitrogen-containing heterocyclic polyester polyol, 10-20 parts of polyether polyol, 20-35 parts of chlorinated paraffin, 2-5 parts of foam stabilizer, 1-2 parts of catalyst, 15-20 parts of propellant, 3-4 parts of flame retardant, 0.5 parts of anti-settling agent -1 part, 1-3 parts of reinforcing agent and auxiliary anti-settling filler.

The isocyanate is polymethylene polyphenyl polyisocyanate, and the NCO mass fraction of PAPI is 30-32%. The number-average molecular weight of the modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture is 300-3000, the functionality is 2-3, and the hydroxyl value is 30-300 mgKOH/g. The number-average molecular weight of the nitrogen-containing heterocyclic polyester polyol is 300-3000, the functionality is 2-3, and the hydroxyl value is 30-300 mgKOH/g. One or more of the products of Evonik Degussa, Zhongshan Dongjun, Hangzhou Chongyao and Nanjing Mesid are selected as the foam stabilizer. The catalyst is DMDEE. The propellant is a mixture of propane and dimethyl ether. The flame retardant is TCPP and micron antimony trioxide. The anti-settling agent is fumed silica. The reinforcing agent is calcium carbonate, and the auxiliary anti-sedimentation filler is silicon micropowder, both of calcium carbonate and silicon micropowder are above 1500 mesh. Among them, antimony trioxide, calcium carbonate and microsilica are dried at 100-120°C for more than 2 hours

The preparation method of the caulking agent is as follows:

S1. Modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, nitrogen-containing heterocyclic polyester polyol, polyether polyol, chlorinated paraffin, foam stabilizer, catalyst, flame retardant, anti-settling Stir the agent, reinforcing agent and auxiliary anti-settling agent evenly to form a composite material;

S2, filling the combined material and the isocyanate into the pressure tank together;

S3. When sealing the valve port, use the aerosol filling equipment to fill the propellant into the pressure tank;

S4. Shake and mix evenly after covering, and it can be used normally after being placed at room temperature for a week.

The effect of adopting the formula of a flame-retardant polyurethane foam sealant in the embodiment of the present application is: instead of the flame-retardant method of the previous polyurethane foam sealant, nitrogen, phosphorus , benzene ring and other elements, so that the surface of the caulking agent can produce a uniform carbon foam layer when it burns, which can block the heat source and air, and effectively improve the flame retardancy of the caulking agent itself. The structure of the nitrogen heterocycle and the benzene ring effectively improves the thermal stability of the caulking agent, and at the same time, the flexible polyether segment of the macromolecule is used to balance the rigidity of the benzene ring and the nitrogen-containing heterocycle, so as to meet the size of the product at high temperature in summer Stability and low temperature toughness in winter, and improve the flame retardancy and calorific value from the main chain segment itself, and raise the flame retardancy to B2 level; make the product not only have stable and good properties in high temperature and low temperature environments, but also reduce The probability of cracks or poor sealing due to shrinkage due to the brittle structure of the product in a low temperature environment is eliminated.

On this basis, a small amount of flame retardant TCPP is added to assist flame retardancy, among which antimony trioxide is selected to be micron-sized and subjected to specific heat treatment to control the particle size and humidity, and to carry out synergistic flame retardancy with the main filler high-viscosity chlorinated paraffin , with the addition of fumed silica to reduce the sedimentation of antimony trioxide, effectively reducing the problem of uneven distribution of antimony trioxide, and improving the use effect of the caulking agent; together with chlorinated paraffin, the material of the caulking agent Excellent thermal stability, which increases the effective service life of the sealant. Through the design of main raw materials and the addition of specific flame retardants, the flame retardant grade of polyurethane foam can be improved to B2 grade while ensuring the normal use effect of polyurethane foam, which improves the traditional method of improving the flame retardant grade of caulking agents and reduces the use of products effect flaws. Reinforcing agent and auxiliary anti-settling filler can not only achieve the effect of reinforcement and hardening, but also improve heat resistance, and more importantly, evenly and effectively disperse the flame retardant to prevent the flame retardant from sticking to the bottom and shaking unevenly when it is used. It affects the construction and flame retardant effect, and improves the defect that the traditional method of improving the flame retardant grade of the sealant reduces the product use effect.

The embodiments of this specific implementation mode are all preferred embodiments of the application, and are not intended to limit the scope of protection of the application. Therefore: all equivalent changes made according to the structure, shape, and principle of the application should be covered by the application. Within the protection scope of this application.

Claims (10)

1. A flame-retardant polyurethane foam sealant, characterized in that: the composition is 20-40 parts of isocyanate, 20-35 parts of modified phosphorus-containing, halogen-containing or polyether polyol mixture containing benzene ring, nitrogen-containing heterocyclic 5-10 parts of polyester polyol, 10-20 parts of polyether polyol, 20-35 parts of chlorinated paraffin, 2-5 parts of foam stabilizer, 1-2 parts of catalyst, 15-20 parts of propellant, flame retardant 3-4 parts, 0.5-1 parts of anti-settling agent, 1-3 parts of reinforcing agent and auxiliary anti-settling filler. 2. A flame-retardant polyurethane foam caulking agent according to claim 1, characterized in that: the flame retardant is TCPP and antimony trioxide. 3. A flame-retardant polyurethane foam caulking agent according to claim 2, characterized in that: the anti-settling agent is fumed silica. 4. A flame-retardant polyurethane foam sealant according to claim 2, characterized in that antimony trioxide is pre-dried at 100-120°C for more than 2 hours. 5. A flame-retardant polyurethane foam sealant according to claim 3, characterized in that: the reinforcing agent is calcium carbonate, the auxiliary anti-settling filler is silicon micropowder, and both the reinforcing agent and the auxiliary anti-settling filler are 1500 mesh above. 6. A flame-retardant polyurethane foam caulking agent according to claim 1, characterized in that: the selected foam stabilizer is Evonik Degussa, Zhongshan Dongjun, Hangzhou Chongyao, Nanjing Meister products one or more of. 7. A flame-retardant polyurethane foam caulking agent according to claim 1, characterized in that: the isocyanate is polymethylene polyphenyl polyisocyanate, wherein the NCO mass fraction of PAPI is 30-32%. 8. A flame-retardant polyurethane foam sealant according to claim 1, characterized in that: the number-average molecular weight of the modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture is 300-3000, and the functionality 2-3, hydroxyl value 30-300mgKOH/g; The number-average molecular weight of the nitrogen-containing heterocyclic polyester polyol is 300-3000, the functionality is 2-3, and the hydroxyl value is 30-300 mgKOH/g. 9. A flame-retardant polyurethane foam joint filler according to claim 5, characterized in that: the reinforcing agent and the auxiliary anti-settling filler are pre-dried at 100-120°C for more than 2 hours. 10. A method for preparing a flame-retardant polyurethane foam caulking agent, comprising the caulking agent according to any one of claims 1-9, characterized in that: comprising the steps of: S1. Modified phosphorus-containing, halogen-containing or benzene ring-containing polyether polyol mixture, nitrogen-containing heterocyclic polyester polyol, polyether polyol, chlorinated paraffin, foam stabilizer, catalyst, flame retardant, anti-settling Agent, reinforcing agent and auxiliary anti-settling filler are stirred evenly to form a composite material; S2, filling the combined material and the isocyanate into the pressure tank together; S3. When sealing the valve port, use the aerosol filling equipment to fill the propellant into the pressure tank; S4. Shake and mix evenly after covering, and it can be used normally after being placed at room temperature for a week.