Polyurethane pressure-sensitive adhesive composition and manufacturing process thereof

Abstract

The invention relates to the field of polyurethane pressure-sensitive adhesives, in particular to a polyurethane pressure-sensitive adhesive composition and a manufacturing process thereof, which are used for solving the problems that the existing polyurethane pressure-sensitive adhesive is inflammable and has potential safety hazards, and the application of the existing polyurethane pressure-sensitive adhesive in occasions with higher fireproof requirements is limited. The polyurethane pressure-sensitive adhesive composition comprises a plurality of key components which play important roles respectively, polyurethane resin is utilized to provide excellent bonding performance and elasticity for the pressure-sensitive adhesive, firmness and convenience during fixation of various base materials are ensured, and secondly, the pressure-sensitive adhesive composition has the advantages that the pressure-sensitive adhesive composition can be used for fixing various base materials; according to the phosphorus-boron flame retardant and the modified nitrogen-sulfur intercalated hydrotalcite, flame-retardant components are doped in a polymer network of polyurethane resin, so that the flame-retardant property of the pressure-sensitive adhesive and the stability of the pressure-sensitive adhesive in a high-temperature environment are effectively improved, the pressure-sensitive adhesive can adapt to various harsh environmental conditions, the reliability and durability of the pressure-sensitive adhesive in complex application are ensured, and the flame-retardant property of the pressure-sensitive adhesive is improved. In addition, the manufacturing process is simple, industrial production is easy to achieve, and the manufacturing process has high application value.

Description

Technical Field

[0001] The present invention relates to the field of polyurethane pressure - sensitive adhesives, and particularly to a polyurethane pressure - sensitive adhesive composition and its manufacturing process. Background Art

[0002] In modern materials science, polyurethane pressure - sensitive adhesives have been widely used in fields such as electronic components, composite materials, and packaging materials due to their excellent adhesive properties, flexibility, and chemical resistance. However, polyurethane materials themselves are flammable, resulting in polyurethane pressure - sensitive adhesives usually having relatively high combustion performance, which is a potential safety hazard in environments with a high incidence of fires and limits their application in some occasions with high fire - prevention requirements.

[0003] Therefore, developing a polyurethane pressure - sensitive adhesive composition and its manufacturing process is of great significance for improving the flame - retardant performance of polyurethane pressure - sensitive adhesives. Summary of the Invention

[0004] In order to overcome the above - mentioned technical problems, the purpose of the present invention is to provide a polyurethane pressure - sensitive adhesive composition and its manufacturing process, which solve the problems that the existing polyurethane pressure - sensitive adhesives are flammable, pose safety hazards, and limit their application in occasions with high fire - prevention requirements.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A polyurethane pressure - sensitive adhesive composition, comprising the following components in parts by weight:

[0007] Polypropylene glycol 40 - 50 parts, diphenylmethane diisocyanate 28 - 36 parts, phosphorus - boron flame retardant 3 - 9 parts, modified nitrogen - sulfur intercalated hydrotalcite 6 - 14 parts, catalyst 0.01 - 0.05 parts, antioxidant 0.3 - 0.7 parts, chain extender 3 - 7 parts, and solvent 50 - 60 parts;

[0008] Among them, the phosphorus - boron flame retardant is prepared by the following steps:

[0009] Step a1: Add pentaerythritol, phosphoric acid, and p - toluenesulfonic acid into a three - necked flask equipped with a stirrer and a thermometer, stir and react at a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min for 10 - 20 min, then raise the temperature to 110 - 120 °C and continue stirring and reacting for 4 - 5 h. After the reaction is completed, cool the reaction product to room temperature, then wash it with distilled water 3 - 5 times, and then place it in a vacuum drying oven and dry it at a temperature of 50 - 55 °C for 2 - 3 h to obtain a phosphate ester intermediate;

[0010] Step a2: Add the phosphate ester intermediate, boric acid, and hydrochloric acid solution into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 - 20 min under the conditions of a temperature of 25 - 30°C and a stirring rate of 200 - 300 r / min. Then, raise the temperature to 110 - 120°C and continue stirring and reacting for 1 - 2 h. After that, raise the temperature to 150 - 160°C and continue stirring and reacting for 3 - 5 h. After the reaction is completed, cool the reaction product to room temperature, then remove the solvent by rotary evaporation. Then, wash it 3 - 5 times with cyclohexane and anhydrous acetone in sequence. Then, place it in a vacuum drying oven and dry it for 2 - 3 h under the condition of a temperature of 80 - 85°C to obtain the phosphorus-boron flame retardant.

[0011] As a further scheme of the present invention: The dosage ratio of the pentaerythritol, phosphoric acid, and p-toluenesulfonic acid in step a1 is 10 mmol: 10 mmol: 0.01 - 0.02 g.

[0012] As a further scheme of the present invention: The dosage ratio of the phosphate ester intermediate, boric acid, and hydrochloric acid solution in step a2 is 30 mmol: 10 mmol: 30 - 40 mL.

[0013] As a further scheme of the present invention: The mass fraction of the hydrochloric acid solution in step a2 is 4 - 5%.

[0014] As a further scheme of the present invention: The modified nitrogen-sulfur intercalated hydrotalcite is prepared by the following steps:

[0015] Step b1: Add the hydrotalcite and deionized water into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a constant pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 10 - 20 min under the conditions of a temperature of 25 - 30°C and a stirring rate of 200 - 300 r / min. Then, raise the temperature to 60 - 65°C and continue stirring and reacting for 30 - 35 min. Then, dropwise add the sulfamic acid solution drop by drop while stirring, control the dropping rate at 1 - 2 drops / s. After the dropping is completed, continue stirring and reacting for 4 - 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate 3 - 5 times with distilled water. Then, place it in a vacuum drying oven and dry it for 3 - 4 h under the condition of a temperature of 60 - 65°C to obtain the nitrogen-sulfur intercalated hydrotalcite;

[0016] Step b2: Add the nitrogen-sulfur intercalated hydrotalcite, silane coupling agent KH792, absolute ethanol, and deionized water into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 - 20 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min. Then, raise the temperature to 80 - 85 °C and continue to stir and react for 8 - 10 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 3 - 5 times, and then place it in a vacuum drying oven and dry it for 6 - 8 h under the condition of a temperature of 50 - 55 °C to obtain the modified nitrogen-sulfur intercalated hydrotalcite.

[0017] As a further scheme of the present invention: The dosage ratio of the hydrotalcite, deionized water, and sulfamic acid solution in step b1 is 5 g : 40 - 50 mL : 30 - 40 mL.

[0018] As a further scheme of the present invention: The hydrotalcite in step b1 is Macklin H875612 magnesium-aluminum hydrotalcite; the sulfamic acid solution is a solution formed by dissolving sulfamic acid in deionized water according to 1 - 1.5 g : 10 mL.

[0019] As a further scheme of the present invention: The dosage ratio of the nitrogen-sulfur intercalated hydrotalcite, silane coupling agent KH792, absolute ethanol, and deionized water in step b2 is 2 g : 1 - 6 g : 30 - 35 mL : 8 - 10 mL.

[0020] As a further scheme of the present invention: A manufacturing process of a polyurethane pressure-sensitive adhesive composition includes the following steps:

[0021] Step one: Weigh 40 - 50 parts by weight of polypropylene glycol, 28 - 36 parts of diphenylmethane diisocyanate, 3 - 9 parts of a phosphorus-boron flame retardant, 6 - 14 parts of the modified nitrogen-sulfur intercalated hydrotalcite, 0.01 - 0.05 parts of a catalyst, 0.3 - 0.7 parts of an antioxidant, 3 - 7 parts of a chain extender, and 50 - 60 parts of a solvent, and set aside.

[0022] Step two: Add the polypropylene glycol, diphenylmethane diisocyanate, and the catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react for 2 - 4 h under the conditions of a temperature of 70 - 80 °C and a stirring rate of 200 - 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer.

[0023] Step 3: Add the polyurethane prepolymer, chain extender, and solvent into a reaction kettle, introduce nitrogen for protection, and stir and react for 40 - 60 min under the conditions of a temperature of 60 - 70 °C and a stirring rate of 200 - 300 r / min. Then add the phosphorus-boron flame retardant, modified nitrogen-sulfur intercalated hydrotalcite, and antioxidant and continue to stir and react for 20 - 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain the polyurethane pressure-sensitive adhesive composition.

[0024] As a further scheme of the present invention: the polypropylene glycol is PPG-2000;

[0025] The catalyst is dibutyltin dilaurate;

[0026] The antioxidant is antioxidant 1010;

[0027] The chain extender is trimethylolpropane;

[0028] The solvent is ethyl acetate.

[0029] The beneficial effects of the present invention:

[0030] A polyurethane pressure-sensitive adhesive composition and its manufacturing process of the present invention obtain a polyurethane prepolymer by stirring and reacting polypropylene glycol, diphenylmethane diisocyanate, and a catalyst, and cooling the reaction product after the reaction is completed. Then, stir and react the polyurethane prepolymer, chain extender, and solvent, and then add the phosphorus-boron flame retardant, modified nitrogen-sulfur intercalated hydrotalcite, and antioxidant and continue to stir and react. After the reaction is completed, cool the reaction product to obtain the polyurethane pressure-sensitive adhesive composition; this polyurethane pressure-sensitive adhesive composition contains a variety of key components, each playing an important role. First, using polypropylene glycol and diphenylmethane diisocyanate as raw materials for polymerization and a chain extender for chain extension to form a polyurethane resin, the polyurethane resin provides excellent adhesive properties and elasticity for the pressure-sensitive adhesive, ensuring firmness and convenience in fixing various substrates. Secondly, the phosphorus-boron flame retardant and modified nitrogen-sulfur intercalated hydrotalcite effectively improve the flame retardant performance and stability of the pressure-sensitive adhesive under high-temperature environments by doping flame retardant components into the polymer network of the polyurethane resin, and can improve the comprehensive mechanical properties of the pressure-sensitive adhesive, thereby enabling the pressure-sensitive adhesive to adapt to various harsh environmental conditions and ensuring reliability and durability in complex applications. And this manufacturing process is simple and easy to realize industrial production, with high application value.

[0031] In the process of preparing the polyurethane pressure-sensitive adhesive composition, a phosphorus-boron flame retardant was first prepared. First, pentaerythritol and phosphoric acid were reacted, and three hydroxyl groups on pentaerythritol reacted with three phosphate groups on phosphoric acid to form phosphate ester groups, obtaining a phosphate ester intermediate. Then, the phosphate ester intermediate and boric acid were reacted, and the hydroxyl groups on the phosphate ester intermediate reacted with three boric acid groups on boric acid to form borate ester groups, obtaining the phosphorus-boron flame retardant; the molecular structure of this phosphorus-boron flame retardant contains a large amount of phosphorus and boron elements. When the phosphorus element decomposes upon heating, it will first produce phosphorus-containing compounds such as phosphoric acid and metaphosphoric acid, which have strong dehydration ability, prompting the pressure-sensitive adhesive to undergo a dehydration reaction, thereby forming a dense char layer. Moreover, the phosphorus element can also act as a free radical scavenger during the combustion process, and can quickly react with these active free radicals in the flame to convert them into relatively stable compounds, thus inhibiting the continuous progress of combustion. When the boron element is heated, it will melt and form a glassy coating layer on the material surface. This coating layer combines tightly with the char layer formed by the phosphorus element, filling the pores in the char layer to make it more dense, further hindering the penetration of oxygen and heat, and further inhibiting the spread of the flame; therefore, this phosphorus-boron flame retardant has excellent flame retardant and fire prevention properties, and adding it to the pressure-sensitive adhesive can greatly improve its flame retardant performance.

[0032] In the process of preparing the polyurethane pressure-sensitive adhesive composition, a modified nitrogen-sulfur intercalated hydrotalcite was also prepared. First, amino sulfonic acid was used as a raw material to dope nitrogen and sulfur elements into the hydrotalcite to obtain nitrogen-sulfur intercalated hydrotalcite. Then, the nitrogen-sulfur intercalated hydrotalcite was modified with the silane coupling agent kh792 to obtain the modified nitrogen-sulfur intercalated hydrotalcite; after being modified with the silane coupling agent kh792, the dispersion performance of the nitrogen-sulfur intercalated hydrotalcite can be greatly improved, enabling it to be evenly dispersed in the pressure-sensitive adhesive, and introducing a large number of amino groups and imino groups, so that it can form chemical bonds with the polyurethane resin, further enhancing the interfacial bonding force with the pressure-sensitive adhesive. Moreover, the hydrotalcite has a function similar to inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, decomposing at high temperatures, absorbing a large amount of heat, reducing the temperature of the material surface, thereby slowing down the combustion rate, and the decomposition products form a dense protective layer on the material surface, isolating oxygen and heat, and preventing the further development of combustion. At the same time, the intercalated nitrogen and sulfur elements will release flame retardant gases such as ammonia, nitrogen, and sulfur dioxide during the thermal decomposition process, diluting the concentration of combustible gases and oxygen, and inhibiting the combustion reaction; therefore, this modified nitrogen-sulfur intercalated hydrotalcite has excellent flame retardant and fire prevention properties, and adding it to the pressure-sensitive adhesive can greatly improve its flame retardant performance. Specific embodiments

[0033] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0034] Example 1:

[0035] This example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0036] Step S1: Add 10 mmol of pentaerythritol, 10 mmol of phosphoric acid, and 0.01 g of p-toluenesulfonic acid into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 min under the conditions of a temperature of 25°C and a stirring rate of 200 r / min. Then, continue to stir and react for 4 h under the condition of raising the temperature to 110°C. After the reaction is completed, cool the reaction product to room temperature, then wash it 3 times with distilled water, and then place it in a vacuum drying oven and dry it for 2 h under the condition of a temperature of 50°C to obtain a phosphate ester intermediate;

[0037] Step S2: Add 30 mmol of phosphate ester intermediate, 10 mmol of boric acid, and 30 mL of a hydrochloric acid solution with a mass fraction of 4% into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 min under the conditions of a temperature of 25°C and a stirring rate of 200 r / min. Then, continue to stir and react for 1 h under the condition of raising the temperature to 110°C. Then, continue to stir and react for 3 h under the condition of raising the temperature to 150°C. After the reaction is completed, cool the reaction product to room temperature, then rotate and evaporate to remove the solvent, and then wash it 3 times with cyclohexane and anhydrous acetone in sequence. Then, place it in a vacuum drying oven and dry it for 2 h under the condition of a temperature of 80°C to obtain a phosphorus-boron flame retardant;

[0038] Step S3: Add 5 g of Macklin H875612 magnesium-aluminum hydrotalcite and 40 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a constant pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 10 min under the conditions of a temperature of 25°C and a stirring rate of 200 r / min. Then, continue to stir and react for 30 min under the condition of raising the temperature to 60°C. Then, while stirring, gradually dropwise add 30 mL of an amino sulfonic acid solution formed by dissolving 1 g of amino sulfonic acid in 10 mL of deionized water, control the dropping rate to be 1 drop / s. After the dropping is completed, continue to stir and react for 4 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 3 times with distilled water, and then place it in a vacuum drying oven and dry it for 3 h under the condition of a temperature of 60°C to obtain a nitrogen-sulfur intercalated hydrotalcite;

[0039] Step S4: Add 2 g of nitrogen-sulfur intercalated hydrotalcite, 1 g of silane coupling agent kh792, 30 mL of absolute ethanol, and 8 mL of deionized water into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 min under the conditions of a temperature of 25°C and a stirring rate of 200 r / min. Then, continue to stir and react for 8 h under the condition of heating to 80°C. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 3 times, and then place it in a vacuum drying oven and dry it for 6 h under the condition of a temperature of 50°C to obtain modified nitrogen-sulfur intercalated hydrotalcite;

[0040] Step S5: Weigh 40 parts of polypropylene glycol, 28 parts of diphenylmethane diisocyanate, 3 parts of phosphorus-boron flame retardant, 6 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.01 part of catalyst, 0.3 part of antioxidant, 3 parts of chain extender, and 50 parts of solvent, and set aside; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0041] Step S6: Add polypropylene glycol, diphenylmethane diisocyanate, and the catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react for 2 h under the conditions of a temperature of 70°C and a stirring rate of 200 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0042] Step S7: Add the polyurethane prepolymer, chain extender, and solvent into a reaction kettle, introduce nitrogen for protection, and stir and react for 40 min under the conditions of a temperature of 60°C and a stirring rate of 200 r / min. Then, add the phosphorus-boron flame retardant, modified nitrogen-sulfur intercalated hydrotalcite, and antioxidant and continue to stir and react for 20 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0043] Example 2:

[0044] This example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0045] Step S1: Add 10 mmol of pentaerythritol, 10 mmol of phosphoric acid, and 0.015 of p-toluenesulfonic acid into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 15 min under the conditions of a temperature of 28°C and a stirring rate of 250 r / min. Then, continue to stir and react for 4.5 h under the condition of heating to 115°C. After the reaction is completed, cool the reaction product to room temperature, then wash it 4 times with distilled water, and then place it in a vacuum drying oven and dry it for 2.5 h under the condition of a temperature of 52°C to obtain a phosphate ester intermediate;

[0046] Step S2: Add 30 mmol of phosphate ester intermediate, 10 mmol of boric acid, and 35 mL of hydrochloric acid solution with a mass fraction of 4.5% into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 15 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then, raise the temperature to 115 °C and continue to stir and react for 1.5 h. After that, raise the temperature to 155 °C and continue to stir and react for 4 h. After the reaction is completed, cool the reaction product to room temperature, then rotate and evaporate to remove the solvent. Then, wash it 4 times with cyclohexane and anhydrous acetone in sequence. Then, place it in a vacuum drying oven and dry it for 2.5 h under the condition of a temperature of 82 °C to obtain a phosphorus-boron flame retardant;

[0047] Step S3: Add 5 g of Macklin H875612 magnesium-aluminum hydrotalcite and 45 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a constant-pressure dropping funnel. Introduce nitrogen for protection and stir and react for 15 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then, raise the temperature to 62 °C and continue to stir and react for 32 min. Then, while stirring, gradually add dropwise 35 mL of sulfamic acid solution formed by dissolving 1.2 g of sulfamic acid in 10 mL of deionized water, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 4.5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 4 times with distilled water. Then, place it in a vacuum drying oven and dry it for 3.5 h under the condition of a temperature of 62 °C to obtain a nitrogen-sulfur intercalated hydrotalcite;

[0048] Step S4: Add 2 g of nitrogen-sulfur intercalated hydrotalcite, 3.5 g of silane coupling agent kh792, 32 mL of absolute ethanol, and 9 mL of deionized water into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 15 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then, raise the temperature to 82 °C and continue to stir and react for 9 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 4 times with distilled water. Then, place it in a vacuum drying oven and dry it for 7 h under the condition of a temperature of 52 °C to obtain a modified nitrogen-sulfur intercalated hydrotalcite;

[0049] Step S5: Weigh 45 parts of polypropylene glycol, 32 parts of diphenylmethane diisocyanate, 6 parts of phosphorus-boron flame retardant, 10 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.03 part of catalyst, 0.5 part of antioxidant, 5 parts of chain extender, and 55 parts of solvent according to weight parts for standby; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0050] Step S6: Add polypropylene glycol, diphenylmethane diisocyanate, and a catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react for 3 h under the conditions of a temperature of 75 °C and a stirring rate of 250 r / min. After the reaction ends, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0051] Step S7: Add the polyurethane prepolymer, a chain extender, and a solvent into a reaction kettle, introduce nitrogen for protection, and stir and react for 50 min under the conditions of a temperature of 65 °C and a stirring rate of 250 r / min. Then add a phosphorus-boron flame retardant, a modified nitrogen-sulfur intercalated hydrotalcite, and an antioxidant and continue to stir and react for 25 min. After the reaction ends, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0052] Example 3:

[0053] This example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0054] Step S1: Add 10 mmol of pentaerythritol, 10 mmol of phosphoric acid, and 0.02 g of p-toluenesulfonic acid into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min, then continue to stir and react for 5 h under the condition of heating to 120 °C. After the reaction ends, cool the reaction product to room temperature, then wash it 5 times with distilled water, and then place it in a vacuum drying oven and dry it for 3 h under the condition of a temperature of 55 °C to obtain a phosphate ester intermediate;

[0055] Step S2: Add 30 mmol of the phosphate ester intermediate, 10 mmol of boric acid, and 40 mL of a hydrochloric acid solution with a mass fraction of 5% into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min, then continue to stir and react for 2 h under the condition of heating to 120 °C, and then continue to stir and react for 5 h under the condition of heating to 160 °C. After the reaction ends, cool the reaction product to room temperature, then rotate and evaporate to remove the solvent, then wash it 5 times with cyclohexane and anhydrous acetone in sequence, and then place it in a vacuum drying oven and dry it for 3 h under the condition of a temperature of 85 °C to obtain a phosphorus-boron flame retardant;

[0056] Step S3: Add 5 g of Maclean H875612 magnesium aluminum hydrotalcite and 50 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a constant pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then raise the temperature to 65 °C and continue to stir and react for 35 min. Then, while stirring, gradually add dropwise 40 mL of an aminosulfonic acid solution formed by dissolving 1.5 g of aminosulfonic acid in 10 mL of deionized water, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 5 times with distilled water, and then place it in a vacuum drying oven and dry it at a temperature of 65 °C for 4 h to obtain nitrogen-sulfur intercalated hydrotalcite;

[0057] Step S4: Add 2 g of nitrogen-sulfur intercalated hydrotalcite, 6 g of silane coupling agent kh792, 35 mL of absolute ethanol and 10 mL of deionized water into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then raise the temperature to 85 °C and continue to stir and react for 10 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 5 times with distilled water, and then place it in a vacuum drying oven and dry it at a temperature of 55 °C for 8 h to obtain modified nitrogen-sulfur intercalated hydrotalcite;

[0058] Weigh 50 parts of polypropylene glycol, 36 parts of diphenylmethane diisocyanate, 9 parts of phosphorus-boron flame retardant, 14 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.05 part of catalyst, 0.7 part of antioxidant, 7 parts of chain extender and 60 parts of solvent according to parts by weight for standby; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0059] Step S9: Add polypropylene glycol, diphenylmethane diisocyanate and the catalyst into a reaction kettle. Introduce nitrogen for protection. Stir and react for 4 h under the conditions of a temperature of 80 °C and a stirring rate of 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0060] Step S10: Add the polyurethane prepolymer, the chain extender and the solvent into the reaction kettle. Introduce nitrogen for protection. Stir and react for 60 min under the conditions of a temperature of 70 °C and a stirring rate of 300 r / min. Then add the phosphorus-boron flame retardant, the modified nitrogen-sulfur intercalated hydrotalcite and the antioxidant and continue to stir and react for 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0061] Comparative Example 1:

[0062] This comparative example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0063] Step S1: Weigh 50 parts of polypropylene glycol, 36 parts of diphenylmethane diisocyanate, 0.05 part of catalyst, 0.7 part of antioxidant, 7 parts of chain extender and 60 parts of solvent by weight, and set aside; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0064] Step S2: Add polypropylene glycol, diphenylmethane diisocyanate and the catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react for 4 h under the conditions of a temperature of 80 °C and a stirring rate of 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0065] Step S3: Add the polyurethane prepolymer, chain extender and solvent into a reaction kettle, introduce nitrogen for protection, stir and react for 60 min under the conditions of a temperature of 70 °C and a stirring rate of 300 r / min, then add the antioxidant and continue to stir and react for 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0066] Comparative Example 2:

[0067] This comparative example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0068] Step S1: Add 10 mmol of pentaerythritol, 10 mmol of phosphoric acid and 0.02 g of p-toluenesulfonic acid into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min, then raise the temperature to 120 °C and continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature, then wash it 5 times with distilled water, and then place it in a vacuum drying oven and dry it for 3 h under the conditions of a temperature of 55 °C to obtain a phosphate ester intermediate;

[0069] Step S2: Add 30 mmol of phosphate ester intermediate, 10 mmol of boric acid, and 40 mL of 5% hydrochloric acid solution by mass to a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then, raise the temperature to 120 °C and continue to stir and react for 2 h. After that, raise the temperature to 160 °C and continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature. Then, remove the solvent by rotary evaporation. Then, wash it 5 times with cyclohexane and anhydrous acetone in sequence. Then, place it in a vacuum drying oven and dry it at a temperature of 85 °C for 3 h to obtain a phosphorus-boron flame retardant;

[0070] Step S3: Weigh 50 parts of polypropylene glycol, 36 parts of diphenylmethane diisocyanate, 9 parts of phosphorus-boron flame retardant, 0.05 part of catalyst, 0.7 part of antioxidant, 7 parts of chain extender, and 60 parts of solvent by weight for standby; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0071] Step S4: Add polypropylene glycol, diphenylmethane diisocyanate, and the catalyst to a reaction kettle, introduce nitrogen for protection, and stir and react for 4 h under the conditions of a temperature of 80 °C and a stirring rate of 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0072] Step S5: Add the polyurethane prepolymer, chain extender, and solvent to a reaction kettle, introduce nitrogen for protection, and stir and react for 60 min under the conditions of a temperature of 70 °C and a stirring rate of 300 r / min. Then, add the phosphorus-boron flame retardant and antioxidant and continue to stir and react for 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0073] Comparative Example 3:

[0074] This comparative example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0075] Step S1: Add 5 g of Maclean H875612 magnesium aluminum hydrotalcite and 50 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer, a gas pipe, and a constant-pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then, raise the temperature to 65 °C and continue to stir and react for 35 min. After that, while stirring, gradually add dropwise 40 mL of sulfamic acid solution formed by dissolving 1.5 g of sulfamic acid in 10 mL of deionized water, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 5 times, and then place it in a vacuum drying oven and dry it at 65 °C for 4 h to obtain nitrogen-sulfur intercalated hydrotalcite;

[0076] Step S2: Add 2 g of nitrogen-sulfur intercalated hydrotalcite, 6 g of silane coupling agent kh792, 35 mL of absolute ethanol, and 10 mL of deionized water into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then, raise the temperature to 85 °C and continue to stir and react for 10 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 5 times, and then place it in a vacuum drying oven and dry it at 55 °C for 8 h to obtain modified nitrogen-sulfur intercalated hydrotalcite;

[0077] Step S3: Weigh 50 parts of polypropylene glycol, 36 parts of diphenylmethane diisocyanate, 14 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.05 part of catalyst, 0.7 part of antioxidant, 7 parts of chain extender, and 60 parts of solvent by weight for standby; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0078] Step S4: Add polypropylene glycol, diphenylmethane diisocyanate, and the catalyst into a reaction kettle. Introduce nitrogen for protection. Stir and react for 4 h under the conditions of a temperature of 80 °C and a stirring rate of 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0079] Step S5: Add the polyurethane prepolymer, the chain extender, and the solvent into a reaction kettle. Introduce nitrogen for protection. Stir and react for 60 min under the conditions of a temperature of 70 °C and a stirring rate of 300 r / min. Then, add the modified nitrogen-sulfur intercalated hydrotalcite and the antioxidant and continue to stir and react for 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0080] Comparative Example 4:

[0081] This comparative example is a manufacturing process of a polyurethane pressure-sensitive adhesive composition, including the following steps:

[0082] Step S1: Weigh 50 parts of polypropylene glycol, 36 parts of diphenylmethane diisocyanate, 9 parts of flame retardant TPP, 14 parts of Macklin H875612 magnesium-aluminum hydrotalcite, 0.05 part of catalyst, 0.7 part of antioxidant, 7 parts of chain extender, and 60 parts of solvent by weight, and set aside; the polypropylene glycol is PPG-2000; the catalyst is dibutyltin dilaurate; the antioxidant is antioxidant 1010; the chain extender is trimethylolpropane; the solvent is ethyl acetate;

[0083] Step S2: Add polypropylene glycol, diphenylmethane diisocyanate, and the catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react for 4 h under the conditions of a temperature of 80 °C and a stirring rate of 300 r / min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane prepolymer;

[0084] Step S3: Add the polyurethane prepolymer, chain extender, and solvent into a reaction kettle, introduce nitrogen for protection, and stir and react for 60 min under the conditions of a temperature of 70 °C and a stirring rate of 300 r / min. Then add flame retardant TPP, Macklin H875612 magnesium-aluminum hydrotalcite, and antioxidant and continue to stir and react for 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain a polyurethane pressure-sensitive adhesive composition.

[0085] Perform performance tests on the polyurethane pressure-sensitive adhesive compositions of Examples 1-3 and Comparative Examples 1-4. Test the vertical burning (UL 94) grade according to the ASTM D3801 standard, and the samples are tested according to the size of 125 mm × 12.7 mm × 3.2 mm; test the limiting oxygen index (LOI) according to the ASTM D2863 standard, and the samples are tested according to the size of 80 mm × 10 mm × 4 mm.

[0086] The test results are shown in the following table:

[0087] Sample UL 94 Rating Limiting Oxygen Index, % Example 1 V-0 38.9 Example 2 V-0 40.1 Example 3 V-0 41.5 Comparative Example 1 NR 20.1 Comparative Example 2 V-0 35.5 Comparative Example 3 V-1 28.3 Comparative Example 4 V-0 33.7

[0088] Referring to the data in the above table, based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be known that the polyurethane pressure-sensitive adhesive composition of the present application has excellent flame retardant performance.

[0089] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0090] The above content is only an example and illustration of the present invention. Those skilled in the art to which this technology belongs can make various modifications or supplements to the described specific embodiments or use similar ways to substitute, as long as they do not deviate from the invention or exceed the scope defined by this application, they should all belong to the protection scope of the present invention.

Claims

1. A polyurethane pressure-sensitive adhesive composition, characterized in that, It comprises the following components in parts by weight: 40 - 50 parts of polypropylene glycol, 28 - 36 parts of diphenylmethane diisocyanate, 3 - 9 parts of phosphorus-boron flame retardant, 6 - 14 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.01 - 0.05 parts of catalyst, 0.3 - 0.7 parts of antioxidant, 3 - 7 parts of chain extender, and 50 - 60 parts of solvent; Among them, the phosphorus-boron flame retardant is prepared by the following steps: Step a1: Pentaerythritol, phosphoric acid, and p-toluenesulfonic acid are subjected to a stirring reaction. After the reaction ends, the reaction product is cooled, and then washed and dried to obtain a phosphate ester intermediate; Step a2: The phosphate ester intermediate, boric acid, and hydrochloric acid solution are subjected to a stirring reaction. After the reaction ends, the reaction product is cooled, then rotary evaporated, and then washed and dried to obtain the phosphorus-boron flame retardant.

2. The polyurethane pressure-sensitive adhesive composition according to claim 1, wherein The dosage ratio of pentaerythritol, phosphoric acid, and p-toluenesulfonic acid in step a1 is 10 mmol: 10 mmol: 0.01 - 0.02 g.

3. The polyurethane pressure-sensitive adhesive composition according to claim 1, wherein The dosage ratio of the phosphate ester intermediate, boric acid, and hydrochloric acid solution in step a2 is 30 mmol: 10 mmol: 30 - 40 mL.

4. A polyurethane pressure-sensitive adhesive composition according to claim 1, wherein The mass fraction of the hydrochloric acid solution in step a2 is 4 - 5%.

5. The polyurethane pressure-sensitive adhesive composition according to claim 1, characterized in that, The modified nitrogen-sulfur intercalated hydrotalcite is prepared by the following steps: Step b1: Hydrotalcite and deionized water are subjected to a stirring reaction, and then an amino sulfonic acid solution is added dropwise with stirring. After the addition is complete, the stirring reaction continues. After the reaction ends, the reaction product is cooled, and then centrifuged. The precipitate is washed and dried to obtain nitrogen-sulfur intercalated hydrotalcite; Step b2: The nitrogen-sulfur intercalated hydrotalcite, silane coupling agent kh792, absolute ethanol, and deionized water are subjected to a stirring reaction. After the reaction ends, the reaction product is cooled, and then centrifuged. The precipitate is washed and dried to obtain the modified nitrogen-sulfur intercalated hydrotalcite.

6. The polyurethane pressure-sensitive adhesive composition according to claim 5, wherein, The dosage ratio of hydrotalcite, deionized water, and amino sulfonic acid solution in step b1 is 5 g: 40 - 50 mL: 30 - 40 mL.

7. A polyurethane pressure-sensitive adhesive composition according to claim 5, wherein The hydrotalcite in step b1 is Macklin H875612 magnesium-aluminum hydrotalcite; the amino sulfonic acid solution is a solution formed by dissolving amino sulfonic acid in deionized water according to 1 - 1.5 g: 10 mL.

8. A polyurethane pressure-sensitive adhesive composition according to claim 5, characterized in that, The dosage ratio of the nitrogen-sulfur intercalated hydrotalcite, silane coupling agent kh792, absolute ethanol, and deionized water in step b2 is 2 g: 1 - 6 g: 30 - 35 mL: 8 - 10 mL.

9. A manufacturing process of a polyurethane pressure-sensitive adhesive composition, characterized in that, It comprises the following steps: Step one: Weigh 40 - 50 parts of polypropylene glycol, 28 - 36 parts of diphenylmethane diisocyanate, 3 - 9 parts of phosphorus-boron flame retardant, 6 - 14 parts of modified nitrogen-sulfur intercalated hydrotalcite, 0.01 - 0.05 parts of catalyst, 0.3 - 0.7 parts of antioxidant, 3 - 7 parts of chain extender, and 50 - 60 parts of solvent in parts by weight and set aside; Step two: Add polypropylene glycol, diphenylmethane diisocyanate, and catalyst into a reaction kettle, introduce nitrogen for protection, and stir and react at a temperature of 70 - 80 °C and a stirring rate of 200 - 300 r / min for 2 - 4 h. After the reaction ends, cool the reaction product to room temperature to obtain a polyurethane prepolymer; Step 3: Add the polyurethane prepolymer, chain extender and solvent into a reaction kettle, introduce nitrogen for protection, stir and react for 40 - 60 min under the conditions of a temperature of 60 - 70 °C and a stirring rate of 200 - 300 r / min. Then add the phosphorus-boron flame retardant, modified nitrogen-sulfur intercalated hydrotalcite and antioxidant, and continue to stir and react for 20 - 30 min. After the reaction is completed, cool the reaction product to room temperature to obtain the polyurethane pressure-sensitive adhesive composition.

10. The manufacturing process of a polyurethane pressure-sensitive adhesive composition according to claim 9, characterized in that, The polypropylene glycol is PPG-2000; The catalyst is dibutyltin dilaurate; The antioxidant is antioxidant 1010; The chain extender is trimethylolpropane; The solvent is ethyl acetate.