Damping cloth for optical lens and preparation method thereof

Abstract

The invention discloses a damping cloth for optical lenses and a preparation method thereof, belonging to the technical field of damping cloth. Polyurethane acrylate and isobornyl methacrylate are stirred and mixed, then an initiator and a promoter are added and stirred and mixed, vacuum degassing is performed to obtain a polyurethane acrylate adhesive, the polyurethane acrylate adhesive is evenly rolled on both sides of a melt-blown cloth, and a base cloth is obtained after curing; one side of the base cloth is subjected to a roughening treatment to obtain a base layer, the base layer is spread out with the roughening side facing upward, a polyurethane prepolymer is coated on the roughening side of the base layer, a surface layer is obtained after reaction and curing, and the damping cloth for optical lenses is prepared; after polypropylene resin is modified by modified lignin, its flexibility can be improved; the cured polyurethane acrylate adhesive plays a role in supporting the roughened fibers, and the isocyanate in the polyurethane prepolymer can undergo a condensation reaction with the alcohol hydroxyl group in the modified lignin, so as to increase the bonding force between the base layer and the surface layer.

Description

Technical Field

[0001] The invention belongs to the technical field of damping cloth, and in particular relates to a damping cloth for optical lenses and a preparation method thereof. Background Art

[0002] Optical lenses are made of optical glass, and they need to be ground and polished during their production and preparation. There are two common methods for polishing optical lenses: mechanical polishing and chemical solution polishing. Mechanical polishing is a polishing method that removes the convex parts to be polished by cutting and plastic deformation of the material surface to obtain a smooth surface. Generally, oilstone strips, wool wheels and sandpaper are used; chemical solution polishing requires the use of polishing fluid, that is, a grinding fluid with mechanical action or a chemical-mechanical grinding fluid is used to press a special abrasive tool against the surface of the workpiece for high-speed rotation to achieve a polishing effect.

[0003] The abrasive tool used for the final polishing of optical lenses is generally damping cloth, which is a velvety polishing material with fine texture, soft surface, porosity, elasticity and long service life. When used as a grinding tool, the damping cloth can effectively impregnate the grinding fluid, improve the cutting force while avoiding scratching the workpiece. It is an excellent mirror effect processing material. Existing damping cloth generally uses meltblown cloth as the base material, but after the damping cloth is bonded to the equipment, when the friction between the polished object and the damping cloth is too large during use, the surface layer of the damping cloth is easily separated from the base layer and wrinkled, resulting in a decrease in polishing performance. Therefore, a damping cloth for optical lenses and a preparation method thereof are proposed. Summary of the invention

[0004] The object of the present invention is to provide a damping cloth for optical lenses and a preparation method thereof, so as to solve the problems in the background technology.

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

[0006] A damping cloth for an optical lens comprises a base layer and a surface layer, wherein the thickness of the base layer is 0.8±0.1 mm, and the thickness of the surface layer is 0.4±0.1 mm.

[0007] The damping cloth for optical lenses is prepared by the following steps:

[0008] Step 1: stir and mix polyurethane acrylate and isobornyl methacrylate, then add initiator and accelerator, stir and mix at 1000-1200 r / min, and obtain polyurethane acrylate adhesive after vacuum degassing;

[0009] The dosage ratio of polyurethane acrylate, isobornyl methacrylate, initiator and accelerator is 70g:30g:2g:2g; the initiator is 2-hydroxy-2-methyl-1-phenylpropanone, and the accelerator is methacrylate phosphate.

[0010] Step 2: Roll-coat polyurethane acrylate adhesive on both sides of the meltblown cloth, and obtain a base cloth after curing; roughen one side of the base cloth to obtain a base layer;

[0011] Step 3: Spread out the base layer with the roughened side facing upward, apply polyurethane prepolymer on the roughened side of the base layer, and obtain a surface layer after reaction and curing to prepare a damping cloth for optical lenses.

[0012] Further, polyurethane acrylate is prepared by the following steps:

[0013] Isophorone diisocyanate is stirred for 10-20 minutes under nitrogen protection and 40-45° C., then hydroxyethyl acrylate, p-hydroxyanisole and dibutyltin dilaurate are added, the temperature is raised to 50-55° C. and stirred to react until the conversion rate of isocyanate groups reaches 50%; then the temperature is raised to 60-70° C. and supplementary materials are added, the reaction is carried out until no isocyanate groups are left, and the temperature is lowered and the material is discharged to obtain polyurethane acrylate.

[0014] The usage ratio of isophorone diisocyanate, hydroxyethyl acrylate, p-hydroxyanisole, dibutyltin dilaurate and supplementary material is 22.5g:11.5g:30-35mg:22mg:25g.

[0015] Furthermore, the supplementary material is polyaspartic acid ester, p-hydroxyanisole and dibutyltin dilaurate, and the usage ratio of polyaspartic acid ester, p-hydroxyanisole and dibutyltin dilaurate is 25g:8mg:22mg.

[0016] The polyurethane prepolymer includes a polyurethane prepolymer produced by reacting polyethylene terephthalate and isocyanate as raw materials.

[0017] Furthermore, the meltblown cloth is prepared by the following steps:

[0018] Step 1: Mix 1-allyl-3-methylimidazolium ionic liquid, anhydrous ethanol and deionized water, stir for 30-40 minutes under ultrasonic-assisted conditions to dissolve the 1-allyl-3-methylimidazolium ionic liquid, add silane coupling agent KH560 and continue stirring for 10-20 minutes, adjust the pH value to 5±0.5 with acetic acid solution, then add lignin, continue stirring at 80°C for 3-5 hours, cool, filter, wash the filter cake with anhydrous ethanol 2-3 times, and then vacuum dry the filter cake at 60°C to obtain modified lignin.

[0019] The dosage ratio of 1-allyl-3-methylimidazolium ionic liquid, anhydrous ethanol, deionized water, silane coupling agent KH560 and lignin is 20g:16g:8g:2mL:1g.

[0020] Step 2: vacuum dry the polypropylene resin at 40° C., stir and dissolve the polypropylene resin with N,N-dimethylformamide, then add the modified lignin and stir at 500-800 r / min for 3-5 hours, and remove N,N-dimethylformamide by rotary evaporation to obtain modified polypropylene resin.

[0021] The dosage ratio of polypropylene resin, N,N-dimethylformamide and modified lignin is 20g:80-100mL:1g.

[0022] Step 3: vacuum dry the modified polypropylene resin and vinyl acetate resin at 40°C, then add an antioxidant and stir at 500-800r / min for 15-30min, then transfer to a twin-screw extruder, melt extrude at 185-195°C, slice to obtain blended slices, and use a melt-blown equipment to prepare melt-blown cloth under corresponding melt-blown parameters.

[0023] The usage ratio of modified polypropylene resin, vinyl acetate resin and antioxidant is 85-90g:10-15g:0.2-0.4g. The antioxidant is antioxidant 1010 but is not limited to antioxidant 1010.

[0024] Furthermore, the meltblowing parameters are as follows: head temperature 255-260°C, hot air temperature 250-255°C, wind pressure 0.3-0.4MPa, receiving distance 25±2cm, and mesh curtain speed 0.35-0.4m / min.

[0025] Beneficial effects of the present invention:

[0026] The damping cloth for optical lenses of the present invention has good bonding force between the base layer and the surface layer, which prevents the surface layer from separating or shrinking during use, and meets the use requirements of optical lens polishing.

[0027] The raw materials of polyurethane acrylate adhesive contain polyaspartic acid ester. The introduction of urea-based structure is beneficial to enhance the interaction between the molecular chains of the adhesive. Polyaspartic acid ester contains flexible long chains, which is beneficial to reduce the stress shrinkage of the polyurethane acrylate adhesive after curing, prevent the meltblown cloth from wrinkling, and ensure the softness of the base layer while coating and bonding the meltblown cloth.

[0028] There are active groups such as aromatic groups, phenolic hydroxyl groups, alcoholic hydroxyl groups, carbonyl groups, methoxy groups, and conjugated double bonds in the molecular structure of lignin. Dissolving it in 1-allyl-3-methylimidazole ionic liquid helps to improve its reaction activity, increase the grafting efficiency of KH560, and improve the dispersibility and thermal stability of the modified lignin, thereby reducing its decomposition in the subsequent preparation of meltblown cloth. The temperature of the die head is high during the meltblowing process, but the production process is fast, and the modified lignin will not decompose too much.

[0029] Polypropylene resin has good heat resistance and tensile strength, but poor flexibility. After modifying polypropylene resin with modified lignin, its flexibility can be improved, and the introduced polar groups can also promote the bonding strength between polyurethane acrylate adhesive and meltblown cloth; vinyl acetate resin can also increase the elasticity of meltblown cloth. After the base layer is roughened, the fibers containing modified lignin in the meltblown cloth are exposed again, and the cured polyurethane acrylate adhesive plays a role in supporting the fibers and preventing the fibers from collapsing; when preparing the surface layer, the isocyanate in the polyurethane prepolymer can react with the alcohol hydroxyl in the modified lignin to increase the bonding strength between the base layer and the surface layer, prevent the base layer and the surface layer from separating, and ensure the performance of the damping cloth. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides a meltblown cloth, and the specific preparation steps are as follows:

[0033] Step 1: 2 kg of 1-allyl-3-methylimidazolium ionic liquid, 1.6 kg of anhydrous ethanol and 800 g of deionized water were mixed, and stirred for 30 min under ultrasonic-assisted conditions to dissolve the 1-allyl-3-methylimidazolium ionic liquid. 200 mL of silane coupling agent KH560 was added and continued to stir for 10 min. The pH value was adjusted to 5±0.5 with acetic acid solution, and then 100 g of lignin was added. Stirring was continued at 80° C. for 3 h, cooled, filtered, and the filter cake was washed twice with anhydrous ethanol. The filter cake was then vacuum dried at 60° C. to obtain modified lignin.

[0034] Step 2: 2 kg of polypropylene resin was vacuum dried at 40°C, the polypropylene resin was stirred and dissolved with 8 L of N, N-dimethylformamide, and then 100 g of modified lignin was added and stirred at 500 r / min for 3 h, and N, N-dimethylformamide was removed by rotary evaporation to obtain modified polypropylene resin.

[0035] Step 3: 850 g of modified polypropylene resin and 100 g of vinyl acetate resin were vacuum dried at 40 ° C, and then 2 g of antioxidant 1010 was added and stirred at 500 r / min for 15 min, and then transferred to a twin-screw extruder, melt-extruded at 185 ° C, sliced ​​to obtain blended slices, and the blended slices were prepared into melt-blown cloth using a melt-blown equipment under corresponding melt-blown parameters.

[0036] The specific meltblowing parameters are: head temperature 255°C, hot air temperature 250°C, wind pressure 0.3MPa, receiving distance 23cm, and mesh curtain speed 0.35m / min.

[0037] Example 2

[0038] This embodiment provides a meltblown cloth, and the specific preparation steps are as follows:

[0039] Step 1: 2 kg of 1-allyl-3-methylimidazolium ionic liquid, 1.6 kg of anhydrous ethanol and 800 g of deionized water were mixed, and stirred for 35 min under ultrasonic-assisted conditions to dissolve the 1-allyl-3-methylimidazolium ionic liquid. 200 mL of silane coupling agent KH560 was added and continued to stir for 15 min. The pH value was adjusted to 5±0.5 with acetic acid solution, and then 100 g of lignin was added. Stirring was continued at 80° C. for 4 h, cooled, filtered, and the filter cake was washed twice with anhydrous ethanol. The filter cake was then vacuum dried at 60° C. to obtain modified lignin.

[0040] Step 2: 2 kg of polypropylene resin was vacuum dried at 40° C., the polypropylene resin was stirred and dissolved with 9 L of N, N-dimethylformamide, and then 100 g of modified lignin was added and stirred at 600 r / min for 4 h, and N, N-dimethylformamide was removed by rotary evaporation to obtain modified polypropylene resin.

[0041] Step 3: 870 g of modified polypropylene resin and 120 g of vinyl acetate resin were vacuum dried at 40 ° C, and then 3 g of antioxidant 1010 was added and stirred at 600 r / min for 20 min, and then transferred to a twin-screw extruder, melt-extruded at 190 ° C, sliced ​​to obtain blended slices, and the blended slices were prepared into melt-blown cloth using a melt-blown equipment under corresponding melt-blowing parameters.

[0042] The specific meltblowing parameters are: head temperature 258°C, hot air temperature 252°C, wind pressure 0.35MPa, receiving distance 25cm, and mesh curtain speed 0.38m / min.

[0043] Example 3

[0044] This embodiment provides a meltblown cloth, and the specific preparation steps are as follows:

[0045] Step 1: 2 kg of 1-allyl-3-methylimidazolium ionic liquid, 1.6 kg of anhydrous ethanol and 800 g of deionized water were mixed, stirred for 40 min under ultrasonic-assisted conditions to dissolve the 1-allyl-3-methylimidazolium ionic liquid, 200 mL of silane coupling agent KH560 was added and continued to stir for 20 min, the pH value was adjusted to 5±0.5 with acetic acid solution, and then 100 g of lignin was added, and continued to stir at 80° C. for 5 h, cooled, filtered, and the filter cake was washed with anhydrous ethanol 3 times, and then the filter cake was vacuum dried at 60° C. to obtain modified lignin.

[0046] Step 2: 2 kg of polypropylene resin was vacuum dried at 40° C., the polypropylene resin was stirred and dissolved with 10 L of N, N-dimethylformamide, and then 100 g of modified lignin was added and stirred at 800 r / min for 5 h, and N, N-dimethylformamide was removed by rotary evaporation to obtain modified polypropylene resin.

[0047] Step 3: 900 g of modified polypropylene resin and 150 g of vinyl acetate resin were vacuum dried at 40 ° C, and then 4 g of antioxidant 1010 was added and stirred at 800 r / min for 30 min, and then transferred to a twin-screw extruder, melt-extruded at 195 ° C, sliced ​​to obtain blended slices, and the blended slices were prepared into melt-blown cloth using a melt-blown equipment under corresponding melt-blown parameters.

[0048] The specific meltblowing parameters are: head temperature 260°C, hot air temperature 255°C, wind pressure 0.4MPa, receiving distance 27cm, and mesh curtain speed 0.4m / min.

[0049] Example 4

[0050] This embodiment provides a damping cloth for optical lenses, and the specific preparation steps are as follows:

[0051] Step 1: 2.5 kg of polyaspartic acid ester, 0.8 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are stirred and mixed to obtain a supplementary material; 2.25 kg of isophorone diisocyanate is stirred for 10 minutes under nitrogen protection and 40° C., and then 1.15 kg of hydroxyethyl acrylate, 3 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are added, the temperature is raised to 50° C. and stirred for reaction, and the conversion rate of the isocyanate group is determined by toluene-di-n-butylamine titration method to reach 50%; then the temperature is raised to 60° C. and 2.5 kg of supplementary material is added, and the reaction is determined by toluene-di-n-butylamine titration method to determine that there is no isocyanate group, and the temperature is lowered and the material is discharged to obtain polyurethane acrylate.

[0052] Step 2: 700 g of polyurethane acrylate and 300 g of isobornyl methacrylate were stirred and mixed, and then 20 g of initiator and 20 g of accelerator were added and stirred and mixed at 1000 r / min, and a polyurethane acrylate adhesive was obtained after vacuum degassing.

[0053] Step 3: Use the meltblown cloth in Example 1, roll-coat the polyurethane acrylate adhesive on both sides of the meltblown cloth, obtain the base cloth after curing, roughen one side of the base cloth, and then spread the base layer with the roughened side facing up to obtain a base layer with a thickness of 0.8±0.1 mm.

[0054] Step 4: Stir and mix ethylene terephthalate and isophorone diisocyanate and heat to 80°C, then drop dibutyltin dichloride, stir and react for 2 hours, add 1,4-butanediol and stir for 60 seconds to obtain a polyurethane prepolymer; apply the polyurethane prepolymer on the roughened side of the base layer, and after reaction and curing, obtain a surface layer with a thickness of 0.4±0.1 mm to prepare a damping cloth for optical lenses.

[0055] Example 5

[0056] This embodiment provides a damping cloth for optical lenses, and the specific preparation steps are as follows:

[0057] Step 1: 2.5 kg of polyaspartic acid ester, 0.8 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are stirred and mixed to obtain a supplementary material; 2.25 kg of isophorone diisocyanate is stirred for 15 minutes under nitrogen protection and 42° C., and then 1.15 kg of hydroxyethyl acrylate, 3.2 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are added, the temperature is raised to 52° C. and stirred for reaction, and the conversion rate of the isocyanate group is determined by toluene-di-n-butylamine titration method to reach 50%; then the temperature is raised to 65° C. and 2.5 kg of supplementary material is added, and the reaction is determined by toluene-di-n-butylamine titration method to determine that there is no isocyanate group, and the temperature is lowered and the material is discharged to obtain polyurethane acrylate.

[0058] Step 2: 700 g of polyurethane acrylate and 300 g of isobornyl methacrylate were stirred and mixed, and then 20 g of initiator and 20 g of accelerator were added and stirred and mixed at 1100 r / min, and a polyurethane acrylate adhesive was obtained after vacuum degassing.

[0059] Step 3: Use the meltblown cloth in Example 2, roll-coat the polyurethane acrylate adhesive on both sides of the meltblown cloth, obtain the base cloth after curing, roughen one side of the base cloth, and then spread the base layer with the roughened side facing up to obtain a base layer with a thickness of 0.8±0.1 mm.

[0060] Step 4: Stir and mix ethylene terephthalate and isophorone diisocyanate and heat to 80°C, then drop dibutyltin dichloride, stir and react for 2.5 hours, add 1,4-butanediol and stir for 80 seconds to obtain a polyurethane prepolymer; apply the polyurethane prepolymer on the roughened side of the base layer, and after reaction and curing, obtain a surface layer with a thickness of 0.4±0.1 mm to prepare a damping cloth for optical lenses.

[0061] Example 6

[0062] This embodiment provides a damping cloth for optical lenses, and the specific preparation steps are as follows:

[0063] Step 1: 2.5 kg of polyaspartic acid ester, 0.8 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are stirred and mixed to obtain a supplementary material; 2.25 kg of isophorone diisocyanate is stirred for 20 minutes under nitrogen protection and 45° C., then 1.15 kg of hydroxyethyl acrylate, 3.5 g of p-hydroxyanisole and 2.2 g of dibutyltin dilaurate are added, the temperature is raised to 55° C. and stirred for reaction, and the conversion rate of the isocyanate group is determined by toluene-di-n-butylamine titration method to reach 50%; then the temperature is raised to 70° C. and 2.5 kg of supplementary material is added, and the reaction is determined by toluene-di-n-butylamine titration method to determine that there is no isocyanate group, and the temperature is lowered and the material is discharged to obtain polyurethane acrylate.

[0064] Step 2: 700 g of polyurethane acrylate and 300 g of isobornyl methacrylate were stirred and mixed, and then 20 g of initiator and 20 g of accelerator were added and stirred and mixed at 1200 r / min, and a polyurethane acrylate adhesive was obtained after vacuum degassing.

[0065] Step 3: Use the meltblown cloth in Example 3, roll-coat the polyurethane acrylate adhesive on both sides of the meltblown cloth, obtain the base cloth after curing, roughen one side of the base cloth, and then spread the base layer with the roughened side facing up to obtain a base layer with a thickness of 0.8±0.1 mm.

[0066] Step 4: Stir and mix ethylene terephthalate and isophorone diisocyanate and heat to 80°C, then drop dibutyltin dichloride, stir and react for 3 hours, add 1,4-butanediol and stir for 90 seconds to obtain a polyurethane prepolymer; apply the polyurethane prepolymer on the roughened side of the base layer, and after reaction and curing, obtain a surface layer with a thickness of 0.4±0.1 mm to prepare a damping cloth for optical lenses.

[0067] Comparative Example 1: On the basis of Example 3, unmodified polypropylene resin was directly used, 900 g of polypropylene resin and 150 g of vinyl acetate resin were vacuum dried at 40°C, and then 4 g of antioxidant 1010 was added and stirred at 800 r / min for 30 min, and then transferred to a twin-screw extruder, melt-extruded at 195°C, and sliced ​​to obtain blended slices, and the blended slices were used to prepare melt-blown cloth using a melt-blown equipment under corresponding melt-blowing parameters.

[0068] The specific meltblowing parameters are: head temperature 260°C, hot air temperature 255°C, wind pressure 0.4MPa, receiving distance 27cm, and mesh curtain speed 0.4m / min.

[0069] Comparative Example 2: Based on Example 3, no vinyl acetate resin was added and the other steps remained unchanged to prepare a meltblown cloth.

[0070] Comparative Example 3: A damping cloth was prepared using the meltblown cloth in Comparative Example 1 and the method of Example 6.

[0071] Comparative Example 4: A damping cloth was prepared using the meltblown cloth in Comparative Example 2 and the method of Example 6.

[0072] Comparative Example 5: The meltblown cloth in Example 3 is used, and on the basis of Comparative Example 6, the polyurethane prepolymer is directly coated on the surface of the meltblown cloth without being treated with the polyurethane acrylate adhesive, and the other steps remain unchanged to prepare the damping cloth.

[0073] The model of polyaspartic acid ester used in the embodiment is NH2580; polyethylene terephthalate is RE5253-BK504 purchased from DuPont in the United States; the model of polypropylene resin is S2040; the model of vinyl acetate resin is EVA14-2. The polyurethane prepolymer includes a polyurethane prepolymer generated by reacting polyethylene terephthalate and isocyanate as raw materials. According to the ratio of the raw materials in the polyurethane prepolymer and the reaction control, the hardness and density of the damping cloth base layer are adjusted, which will not be described in detail here.

[0074] Performance tests were performed on Examples 1 to 6 and Comparative Examples 1 to 5: the elongation at break and the breaking strength of the meltblown fabrics in Examples 1 to 3 and Comparative Examples 1 to 2 were tested according to GB / T 24218.3-2010; the elastic recovery of the meltblown fabrics in Examples 1 to 3 and Comparative Examples 1 to 2 was tested according to FZ / T70006-2004. The results are shown in Table 1:

[0075] Table 1

[0076] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Longitudinal breaking strength / MPa 1.25 1.27 1.31 1.30 1.32 Transverse rupture strength / MPa 1.25 1.27 1.31 1.28 1.32 Longitudinal elongation at break / % 35 36 38 33 36 Transverse elongation at break / % 35 36 38 32 36 Elastic recovery / % 38 38 39 23 34

[0077] It can be seen from Table 1 that the meltblown fabrics prepared in Examples 1 to 3 have uniform mechanical properties in the transverse and longitudinal directions and have better elastic recovery.

[0078] According to GB / T 1720-2020, the adhesion between the surface layer and the base layer of different damping fabrics in Examples 4 to 6 and Comparative Examples 3 to 5 was tested using a paint film adhesion tester (grade 1 to 7, with grade 1 being the best and grade 7 being the worst). The results are shown in Table 2:

[0079] Table 2

[0080] project Example 4 Example 5 Example 6 Comparative Example 3 Comparative Example 4 Comparative Example 5 Adhesion grade Level 1 Level 1 Level 1 Level 2 Level 1 Level 2

[0081] It can be seen from Table 1 that the adhesion between the damping fabric surface layer and the base layer in Examples 4 to 6 is stronger, wherein the modified polypropylene resin and the urethane acrylate adhesive play a reinforcing role.

[0082] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a damping cloth for an optical lens, characterized in that: The steps include: Step 1: stir and mix polyurethane acrylate and isobornyl methacrylate, then add initiator and accelerator, stir and mix at 1000-1200 r / min, and vacuum degas to obtain polyurethane acrylate adhesive; Step 2: Roll-coat polyurethane acrylate adhesive on both sides of the meltblown cloth, and obtain a base cloth after curing; roughen one side of the base cloth to obtain a base layer; Step 3: Spread out the base layer with the roughened side facing upward, apply a polyurethane prepolymer on the roughened side of the base layer, and obtain a surface layer after reaction and curing, thereby preparing a damping cloth for optical lenses; The meltblown cloth is prepared by the following steps: The modified polypropylene resin and the vinyl acetate resin are dried, stirred with an antioxidant at 500-800 r / min for 15-30 min, melt-extruded at 185-195° C., sliced ​​to obtain blended slices, and melt-blown the blended slices to prepare melt-blown cloth; The modified polypropylene resin is prepared by the following steps: Step 1: dissolve 1-allyl-3-methylimidazolium ionic liquid with anhydrous ethanol and deionized water, add silane coupling agent KH560 and continue stirring for 10-20 minutes, adjust the pH value to 5±0.5 with acetic acid solution, then add lignin, continue stirring at 80° C. for 3-5 hours, cool, filter, wash the filter cake, and dry to obtain modified lignin; Step 2: After drying the polypropylene resin, stir and dissolve it with N,N-dimethylformamide, then add the modified lignin and stir for 3-5 hours at 500-800 r / min, and rotary evaporate to obtain the modified polypropylene resin.

2. The method for preparing a damping cloth for an optical lens according to claim 1, characterized in that: The usage ratio of the polyurethane acrylate, isobornyl methacrylate, initiator and accelerator is 70g:30g:2g:2g.

3. The method for preparing a damping cloth for an optical lens according to claim 2, characterized in that: Polyurethane acrylate is prepared by the following steps: Isophorone diisocyanate is stirred for 10-20 minutes under nitrogen protection and 40-45°C, hydroxyethyl acrylate, p-hydroxyanisole and dibutyltin dilaurate are added, the temperature is raised to 50-55°C and stirred to react until the conversion rate of isocyanate groups reaches 50%, then the temperature is raised to 60-70°C and supplementary materials are added, the reaction is continued until no isocyanate groups are left, and the temperature is lowered and the material is discharged to obtain polyurethane acrylate.

4. The method for preparing a damping cloth for an optical lens according to claim 3, characterized in that: The usage ratio of isophorone diisocyanate, hydroxyethyl acrylate, p-hydroxyanisole, dibutyltin dilaurate and supplementary material is 22.5g:11.5g:30-35mg:22mg:25g.

5. The method for preparing a damping cloth for an optical lens according to claim 3, characterized in that: The supplement material is prepared by mixing polyaspartic acid ester, p-hydroxyanisole and dibutyltin dilaurate in a dosage ratio of 25g:8mg:22mg.

6. The method for preparing a damping cloth for an optical lens according to claim 1, characterized in that: The usage ratio of the modified polypropylene resin, vinyl acetate resin and antioxidant is 85-90g:10-15g:0.2-0.4g.

7. The method for preparing a damping cloth for an optical lens according to claim 1, characterized in that: The usage ratio of the polypropylene resin, N,N-dimethylformamide and modified lignin is 20g:80-100mL:1g.

8. A damping cloth for optical lenses, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 7.