A composite sheet and a processing method thereof

Abstract

The present invention relates to a composite sheet and a processing method thereof. Its raw materials include polyethylene; the opacity is 0.88 to 0.96; the longitudinal wet tensile strength retention rate is MD1, and the transverse wet tensile strength retention rate is CD1; after being treated by an aging process, the longitudinal wet tensile strength retention rate after aging is MD2, and the transverse wet tensile strength retention rate after aging is CD2; the value of MD1 is 0.91 to 0.95; the value of CD1 is 0.86 to 0.93; the ratio of MD1 to MD2 is 1.05:1 to 1.35:1; the ratio of CD1 to CD2 is 1.05:1 to 1.35:1. This application mainly aims at the characteristic that the performance of the spunbond composite sheet deteriorates after being used for a period of time. By simulating the use conditions, that is, the aging test, the performance of the product is verified, and the performance after aging is improved by improving the raw materials and the process, so as to extend the service life of the product and expand its application range.

Description

Technical Field

[0001] The present invention relates to the technical field of textile flash spinning, and specifically, to a composite sheet and a processing method thereof.

Background Art

[0002] In recent years, with the progress of new synthetic fiber technologies, non-woven materials have started to develop towards fineness. Using ultra-fine fiber web-forming technology to obtain non-woven fabric products with excellent covering properties, softness, lightness, uniformity, and unique styles without sacrificing their strength has become the research and development direction of non-woven technology. The reason why the typical product, non-woven fabric made by compounding ultra-fine fibers through flash evaporation technology, is highly regarded by the current non-woven fabric industry is due to its special functions and market applications.

[0003] The main principle of flash spinning is to dissolve a polymer in a certain solvent to form a spinning solution, and then eject it from a spinneret hole. Due to the rapid volatilization of the solvent, the polymer is re-solidified into fibers, and the fibers are adsorbed on a forming curtain to directly form a fiber web. The key to flash spinning lies in dissolving under high pressure and phase separation under low pressure.

[0004] At present, when flash evaporation products are used outdoors for a period of time, especially under high-temperature conditions, there is an obvious technical problem that their wet tensile strength decreases. There is an urgent need to improve the raw materials and processes to overcome this technical problem, delay their service life, and expand their application scope.

Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a composite sheet and a processing method thereof.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A composite sheet, the raw materials of which include polyethylene; the opacity is 0.88 - 0.96; the longitudinal wet tensile strength retention rate is MD1, and the transverse wet tensile strength retention rate is CD1;

[0008] After being treated by an aging process, the longitudinal wet tensile strength retention rate after aging is MD2, and the transverse wet tensile strength retention rate after aging is CD2;

[0009] The value of MD1 is 0.88 - 0.96;

[0010] The value of CD1 is 0.82 - 0.92;

[0011] The ratio of MD1 to MD2 is 1.05:1 - 1.30:1;

[0012] The ratio of CD1 to CD2 is 1.05:1 - 1.30:1;

[0013] Under standard atmospheric conditions, the transverse and longitudinal tensile strengths of the same specimen are measured before and after wetting respectively. The longitudinal wet tensile strength retention rate is the ratio of the longitudinal tensile strength after wetting to the longitudinal tensile strength before wetting, and the transverse wet tensile strength retention rate is the ratio of the transverse tensile strength after wetting to the longitudinal and transverse tensile strengths before wetting. The wetting process conditions for the specimen are as follows: the water temperature for wetting is 40°C, the wetting time is 8 hours, the constant-speed stretching rate is 50 mm / minute, and the relative humidity of the environment during testing is 48 - 52%RH. Among them, the wet tensile strength is tested in accordance with GB / T 24328.4-2009 of the national standard. The wet tensile strength refers to the maximum tensile force per unit width that the wet specimen withstands before fracture after the specimen is wetted in distilled water. The wet tensile strength retention rate refers to the ratio of the tensile strength of the same specimen after wetting to the tensile strength before wetting under standard atmospheric pressure conditions.

[0014] Aging treatment: The irradiance in the wavelength range of 300 - 400 nm is 60 ± 2 w / m 2 , the black standard temperature is 65 ± 2°C, the air temperature in the test chamber is 38 ± 3°C, the relative humidity is 50 ± 10%, and the drying time is 672 hours.

[0015] The main purpose of the aging treatment in this application is to examine the situation of the wet tensile strength retention rate of the sample after four weeks of use, so as to make an optimal judgment on the performance of the product. Then, through the adjustment of raw materials and processes, the best performance of the product can be obtained, thereby extending the service life and application range of the product.

[0016] The opacity of this application is tested in accordance with GB / T 1543-2005 of the national standard. The opacity refers to the ratio of the single-layer emission factor to the internal emission factor of the same specimen.

[0017] The opacity of the composite sheet is 0.88 - 0.90.

[0018] The opacity of the composite sheet is 0.92 - 0.94.

[0019] The opacity of the composite sheet is 0.94 - 0.96.

[0020] The value of MD1 of the composite sheet is 0.88 - 0.92.

[0021] The value of MD1 of the composite sheet is 0.92 - 0.96.

[0022] The value of CD1 of the composite sheet is 0.82 - 0.87.

[0023] The value of CD1 of the composite sheet is 0.87 - 0.92.

[0024] The ratio of MD1 to MD2 of the composite sheet is 1.05:1 to 1.1:1.

[0025] The ratio of MD1 to MD2 of the composite sheet is 1.1:1 to 1.15:1.

[0026] The ratio of MD1 to MD2 of the composite sheet is 1.15:1 to 1.2:1.

[0027] The ratio of MD1 to MD2 of the composite sheet is 1.2:1 to 1.25:1.

[0028] The ratio of MD1 to MD2 of the composite sheet is 1.25:1 to 1.30:1.

[0029] The ratio of CD1 to CD2 of the composite sheet is 1.05:1 to 1.1:1.

[0030] The ratio of CD1 to CD2 of the composite sheet is 1.1:1 to 1.15:1.

[0031] The ratio of CD1 to CD2 of the composite sheet is 1.15:1 to 1.2:1.

[0032] The ratio of CD1 to CD2 of the composite sheet is 1.2:1 to 1.25:1.

[0033] The ratio of CD1 to CD2 of the composite sheet is 1.25:1 to 1.30:1.

[0034] The ratio of MD1 to CD1 of the composite sheet is 1.03:1 to 1.2:1.

[0035] The ratio of MD1 to CD1 of the composite sheet is 1.03:1 to 1.06:1.

[0036] The ratio of MD1 to CD1 of the composite sheet is 1.06:1 to 1.1:1.

[0037] The ratio of MD1 to CD1 of the composite sheet is 1.1:1 to 1.2:1.

[0038] The ratio of MD2 to CD2 of the composite sheet is 1.03:1 to 1.2:1.

[0039] The ratio of MD2 to CD2 of the composite sheet is 1.03:1 to 1.06:1.

[0040] The ratio of MD2 to CD2 of the composite sheet is 1.06:1 to 1.1:1.

[0041] The ratio of MD2 to CD2 of the composite sheet is 1.1:1 to 1.2:1.

[0042] A composite sheet, with a basis weight preferably of 48 to 75 g / m 2 .

[0043] A composite sheet, whose raw materials further include modified chlorinated polypropylene.

[0044] The modified chlorinated polypropylene is a modification obtained by adsorbing barium sulfate and silver oxide on the basis of chlorinated polypropylene.

[0045] The mass fraction of the modified chlorinated polypropylene in the mixture of polyethylene and chlorinated polypropylene is 1.5 to 2.5%.

[0046] A processing method of a composite sheet, which comprises the following steps:

[0047] (1) Prepare a spinning solution

[0048] The spinning solution contains a polymer and a spinning solvent;

[0049] The mass fraction of the polymer in the spinning solution is 13 to 15%.

[0050] The polymer contains polyethylene and modified chlorinated polypropylene.

[0051] The mass fraction of the modified chlorinated polypropylene in the polymer is 1.5 to 2.5%.

[0052] The spinning solvent is one or more of aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, esters, ethers, ketones, or the like.

[0053] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0054] A preparation method of the modified chlorinated polypropylene, which comprises the following steps:

[0055] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and conduct heat treatment at 105 to 110 °C for 0.5 to 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to a barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to a silver nitrate solution so that silver ions are adsorbed on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0056] The chlorinated polypropylene is chlorinated polypropylene with 20 to 40% chlorine (low chlorination degree polypropylene).

[0057] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 10 to 30%.

[0058] The mass fraction of the concentrated sulfuric acid is 80%.

[0059] The mass ratio of sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.06 to 1:0.13.

[0060] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0061] Chlorinated polypropylene is easily soluble in aromatic hydrocarbons, esters, and ketones, which is the same as the solvent for flash spinning in this application. Therefore, it has better compatibility with the polyethylene matrix; this is also an important factor for choosing chlorinated polypropylene as an additive material in this application. Due to the polarity of the molecular structures of chlorinated polypropylene and polyethylene, its strength, heat resistance, and aging resistance are stronger than those of polyethylene. At the same time, because chlorinated polypropylene has good gelling properties, it can improve the compatibility between the product and the polyethylene matrix, and can also increase the retention rate of wet tensile strength and improve the performance of the product. In addition, the sulfonic acid groups of sulfonated chlorinated polypropylene have a strong chelating effect with barium ions, and finally barium sulfate precipitates are formed on the surface of chlorinated polypropylene, and through the chelating effect of chlorinated polypropylene, it plays a fixing role rather than a simple physical mixture; the chlorine-containing groups in chlorinated polypropylene can chelate with silver ions of silver nitrate to form ionic silver chloride, and its silver ions have excellent broad-spectrum antibacterial effects. The final antibacterial effect of the product in this application is tested according to the national standard GB / T 20944.2-2007 Evaluation of antibacterial properties of textiles - Part 2: Absorption method; the bacterial strains used for antibacterial testing are Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli; culture conditions: 37°C ± 2°C, 90% ± 2%; culture time 18 - 24 hours. It is expressed by the antibacterial rate (i.e., the bacteriostatic rate), and those with more than 95% have antibacterial properties, and those with more than 98% have better antibacterial functions.

[0062] (2) Flash spinning process

[0063] Then flash spinning is carried out, the spinning temperature is 180 - 208°C to obtain flash-spun fibers, and then through hot pressing and calendering of the roller, the calendering temperature is 113 - 127°C, the linear pressure of calendering is 9 - 30 N / mm, and finally winding and reeling are carried out to obtain the flash-spun composite sheet.

[0064] Compared with the prior art, the positive effects of the present invention are:

[0065] This application mainly aims at the characteristic that the performance of the flash-spun composite sheet deteriorates after being used for a period of time. This application verifies the performance of the product through simulating the use conditions, that is, the aging test, and improves its performance after aging through the improvement of raw materials and processes to increase the service life of the product and expand its application range.

Specific embodiments

[0066] The following provides specific embodiments of a composite sheet and its processing method of the present invention.

[0067] Example 1

[0068] A processing method of a composite sheet, which comprises the following steps:

[0069] (1) Prepare a spinning solution

[0070] The spinning solution contains a polymer and a spinning solvent;

[0071] The mass fraction of the polymer in the spinning solution is 13%.

[0072] The polymer contains polyethylene and modified chlorinated polypropylene.

[0073] The mass fraction of the modified chlorinated polypropylene in the polymer is 1.5%.

[0074] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0075] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0076] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105 °C for 0.5 - 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; secondly, add the sulfonated chlorinated polypropylene into the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate into the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0077] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 10%.

[0078] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.06.

[0079] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0080] (2) Flash spinning process

[0081] Then carry out flash spinning, the spinning temperature is 198 °C to obtain flash spun fibers, and then through hot pressing and calendering of the roller, the calendering temperature is 113 °C, the linear pressure of calendering is 10 N / mm, and finally winding and winding are carried out to obtain the flash spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0082] Example 2

[0083] A processing method of a composite sheet, which comprises the following steps:

[0084] (1) Prepare the spinning solution

[0085] The spinning solution contains a polymer and a spinning solvent;

[0086] The mass fraction of the polymer in the spinning solution is 14%.

[0087] The polymer contains polyethylene and modified chlorinated polypropylene.

[0088] The mass fraction of the modified chlorinated polypropylene in the polymer is 2%.

[0089] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0090] The preparation method of the modified chlorinated polypropylene includes the following steps:

[0091] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and perform heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0092] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0093] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0094] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0095] (2) Flash spinning process

[0096] Then perform flash spinning, the spinning temperature is 204 °C to obtain flash-spun fibers, and then perform hot pressing and calendering through rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, wind and roll up to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0097] Example 3

[0098] A processing method of a composite sheet, which includes the following steps:

[0099] (1) Prepare the spinning solution

[0100] The spinning solution contains a polymer and a spinning solvent;

[0101] The mass fraction of the polymer in the spinning solution is 15%.

[0102] The polymer comprises polyethylene and modified chlorinated polypropylene.

[0103] The mass fraction of the modified chlorinated polypropylene in the polymer is 2.5%.

[0104] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0105] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0106] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and conduct heat treatment at 110 °C for 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene into the barium chloride solution by means of microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate into the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0107] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 30%.

[0108] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.13.

[0109] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0110] (2) Flash spinning process

[0111] Then, flash spinning is carried out at a spinning temperature of 208 °C to obtain flash spun fibers, which are then subjected to hot pressing and calendering. The calendering temperature is 127 °C and the linear pressure of calendering is 28 N / mm. Finally, winding and rewinding are carried out to obtain the flash spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0112] Comparative Example 1

[0113] A processing method of a composite sheet, which comprises the following steps:

[0114] (1) Prepare the spinning solution

[0115] The spinning solution comprises a polymer and a spinning solvent;

[0116] The mass fraction of the polymer in the spinning solution is 14%.

[0117] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0118] (2) Flash spinning process

[0119] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers, which are then subjected to hot pressing and calendering by rollers. The calendering temperature is 119 °C and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0120] Comparative Example 2

[0121] A processing method of a composite sheet, which comprises the following steps:

[0122] (1) Prepare the spinning solution

[0123] The spinning solution contains a polymer and a spinning solvent;

[0124] The mass fraction of the polymer in the spinning solution is 14%.

[0125] The polymer contains polyethylene and modified chlorinated polypropylene.

[0126] The mass fraction of the modified chlorinated polypropylene in the polymer is 0.5%.

[0127] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0128] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0129] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105 - 110 °C for 0.5 - 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0130] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0131] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0132] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0133] (2) Flash spinning process

[0134] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers. Then, hot pressing and calendering are carried out by roller wheels. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0135] Comparative Example 3

[0136] A processing method of a composite sheet, which comprises the following steps:

[0137] (1) Prepare a spinning solution

[0138] The spinning solution contains a polymer and a spinning solvent;

[0139] The mass fraction of the polymer in the spinning solution is 14%.

[0140] The polymer contains polyethylene and modified chlorinated polypropylene.

[0141] The mass fraction of the modified chlorinated polypropylene in the polymer is 1%.

[0142] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0143] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0144] First, disperse chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; secondly, add the sulfonated chlorinated polypropylene into barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add chlorinated polypropylene-barium sulfate into silver nitrate solution to adsorb silver ions on chlorinated polypropylene-barium sulfate to obtain modified chlorinated polypropylene.

[0145] The mass fraction of chlorinated polypropylene in concentrated sulfuric acid is 20%.

[0146] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0147] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0148] (2) Flash spinning process

[0149] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers, which are then subjected to hot pressing and calendering through rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0150] Comparative Example 4

[0151] A processing method of a composite sheet, which comprises the following steps:

[0152] (1) Prepare the spinning solution

[0153] The spinning solution contains a polymer and a spinning solvent;

[0154] The mass fraction of the polymer in the spinning solution is 14%.

[0155] The polymer contains polyethylene and modified chlorinated polypropylene.

[0156] The mass fraction of the modified chlorinated polypropylene in the polymer is 3%.

[0157] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0158] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0159] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0160] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0161] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0162] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0163] (2) Flash spinning process

[0164] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers. Then, hot pressing and calendering are carried out through rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0165] Comparative Example 5

[0166] A processing method of a composite sheet, which comprises the following steps:

[0167] (1) Prepare a spinning solution

[0168] The spinning solution contains a polymer and a spinning solvent;

[0169] The mass fraction of the polymer in the spinning solution is 14%.

[0170] The polymer contains polyethylene and modified chlorinated polypropylene.

[0171] The mass fraction of the modified chlorinated polypropylene in the polymer is 3.5%.

[0172] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0173] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0174] First, disperse chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to a barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add chlorinated polypropylene-barium sulfate to a silver nitrate solution to adsorb silver ions on chlorinated polypropylene-barium sulfate to obtain modified chlorinated polypropylene.

[0175] The mass fraction of chlorinated polypropylene in concentrated sulfuric acid is 20%.

[0176] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0177] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0178] (2) Flash spinning process

[0179] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers, which are then hot-pressed and calendered by rollers. The calendering temperature is 119 °C and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0180] Comparative Example 6

[0181] A processing method of a composite sheet, which comprises the following steps:

[0182] (1) Prepare a spinning solution

[0183] The spinning solution contains a polymer and a spinning solvent;

[0184] The mass fraction of the polymer in the spinning solution is 10%.

[0185] The polymer contains polyethylene and modified chlorinated polypropylene.

[0186] The mass fraction of the modified chlorinated polypropylene in the polymer is 2%.

[0187] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0188] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0189] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene into the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate into the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0190] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0191] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0192] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0193] (2) Flash spinning process

[0194] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers, which are then subjected to hot pressing and calendering through rollers. The calendering temperature is 119 °C and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain the flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0195] Comparative Example 7

[0196] A processing method for a composite sheet, which comprises the following steps:

[0197] (1) Prepare the spinning solution

[0198] The spinning solution contains a polymer and a spinning solvent;

[0199] The mass fraction of the polymer in the spinning solution is 11%.

[0200] The polymer contains polyethylene and modified chlorinated polypropylene.

[0201] The mass fraction of the modified chlorinated polypropylene in the polymer is 2%.

[0202] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0203] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0204] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105 - 110 °C for 0.5 - 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0205] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0206] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0207] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0208] (2) Flash spinning process

[0209] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers. Then, hot pressing and calendering are carried out through rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0210] Comparative Example 8

[0211] A processing method of a composite sheet, which comprises the following steps:

[0212] (1) Prepare a spinning solution

[0213] The spinning solution contains a polymer and a spinning solvent;

[0214] The mass fraction of the polymer in the spinning solution is 12%.

[0215] The polymer contains polyethylene and modified chlorinated polypropylene.

[0216] The mass fraction of modified chlorinated polypropylene in the polymer is 2%.

[0217] The spinning solvent is a mixture of 3-methylpentane, hexane and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0218] The preparation method of modified chlorinated polypropylene comprises the following steps:

[0219] First, disperse chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add sulfonated chlorinated polypropylene into barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add chlorinated polypropylene-barium sulfate into silver nitrate solution to adsorb silver ions on chlorinated polypropylene-barium sulfate to obtain modified chlorinated polypropylene.

[0220] The mass fraction of chlorinated polypropylene in concentrated sulfuric acid is 20%.

[0221] The mass ratio of sulfonated chlorinated polypropylene to barium chloride in barium chloride solution is 1:0.09.

[0222] The mass ratio of barium chloride in barium chloride solution to silver nitrate in silver nitrate solution is 1:1.

[0223] (2) Flash spinning process

[0224] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers. Then, hot pressing and calendering are carried out through rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain the flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0225] Comparative Example 9

[0226] A processing method of a composite sheet, which comprises the following steps:

[0227] (1) Prepare the spinning solution

[0228] The spinning solution contains a polymer and a spinning solvent;

[0229] The mass fraction of the polymer in the spinning solution is 16%.

[0230] The polymer contains polyethylene and modified chlorinated polypropylene.

[0231] The mass fraction of the modified chlorinated polypropylene in the polymer is 2%.

[0232] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0233] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0234] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene into the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate into the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0235] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0236] The mass ratio of the sulfonated chlorinated polypropylene to barium chloride in the barium chloride solution is 1:0.09.

[0237] The mass ratio of barium chloride in the barium chloride solution to silver nitrate in the silver nitrate solution is 1:1.

[0238] (2) Flash spinning process

[0239] Then, flash spinning is carried out at a spinning temperature of 204 °C to obtain flash-spun fibers, which are then subjected to hot pressing and calendering by rollers. The calendering temperature is 119 °C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain a flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0240] Comparative Example 10

[0241] A processing method of a composite sheet, which comprises the following steps:

[0242] (1) Prepare the spinning solution

[0243] The spinning solution contains a polymer and a spinning solvent;

[0244] The mass fraction of the polymer in the spinning solution is 17%.

[0245] The polymer contains polyethylene and modified chlorinated polypropylene.

[0246] The mass fraction of the modified chlorinated polypropylene in the polymer is 2%.

[0247] The spinning solvent is a mixture of 3-methylpentane, hexane, and trans-1,2-dichloroethylene; the volume ratio of the three is 1:1:1.

[0248] The preparation method of the modified chlorinated polypropylene comprises the following steps:

[0249] First, disperse the chlorinated polypropylene in concentrated sulfuric acid and carry out heat treatment at 105-110 °C for 0.5-1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene to the barium chloride solution by microwave stirring to obtain chlorinated polypropylene-barium sulfate; finally, add the chlorinated polypropylene-barium sulfate to the silver nitrate solution to adsorb silver ions on the chlorinated polypropylene-barium sulfate to obtain the modified chlorinated polypropylene.

[0250] The mass fraction of the chlorinated polypropylene in the concentrated sulfuric acid is 20%.

[0251] The mass ratio of the sulfonated chlorinated polypropylene to the barium chloride in the barium chloride solution is 1:0.09.

[0252] The mass ratio of the barium chloride in the barium chloride solution to the silver nitrate in the silver nitrate solution is 1:1.

[0253] (2) Flash spinning process

[0254] Then, flash spinning is carried out at a spinning temperature of 204°C to obtain flash-spun fibers, which are then subjected to hot pressing and calendering by rollers. The calendering temperature is 119°C, and the linear pressure of calendering is 18 N / mm. Finally, winding and coiling are carried out to obtain the flash-spun composite sheet. The test data of the composite sheet are shown in Table 1.

[0255] Table 1 Test Table of Performance Parameters (The unit of grammage is g / m 2 )

[0256] Grammage Opacity MD1 CD1 MD2 CD2 MD1 / MD2 CD1 / CD2 Antibacterial rate Example 1 50.1 0.90 0.900 0.840 0.800 0.690 1.125 1.217 0.972 Example 2 51.3 0.93 0.930 0.870 0.830 0.740 1.120 1.176 0.985 Example 3 52.8 0.95 0.950 0.900 0.850 0.790 1.118 1.139 0.994 Comparative Example 1 48.9 0.75 0.740 0.660 0.510 0.450 1.451 1.467 0.800 Comparative Example 2 51.7 0.83 0.780 0.760 0.570 0.550 1.368 1.382 0.934 Comparative Example 3 53.6 0.86 0.850 0.800 0.630 0.580 1.349 1.379 0.952 Comparative Example 4 52.1 0.96 0.960 0.910 0.860 0.720 1.116 1.264 0.995 Comparative Example 5 54.5 0.97 0.970 0.930 0.880 0.730 1.102 1.274 0.996 Comparative Example 6 55.1 0.84 0.770 0.680 0.570 0.510 1.351 1.333 0.981 Comparative Example 7 52.5 0.86 0.790 0.700 0.590 0.530 1.339 1.321 0.983 Comparative Example 8 51.4 0.88 0.840 0.720 0.640 0.550 1.313 1.309 0.984 Comparative Example 9 53.1 0.96 0.960 0.900 0.870 0.810 1.103 1.111 0.987 Comparative Example 10 56.1 0.97 0.970 0.920 0.890 0.830 1.090 1.108 0.989

[0257] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A composite sheet, characterized in that, Its raw materials include polyethylene; the opacity is 0.88 - 0.96; the longitudinal wet tensile strength retention rate is MD1, and the transverse wet tensile strength retention rate is CD1; After being treated by the aging process, the longitudinal wet tensile strength retention rate after aging is MD2, and the transverse wet tensile strength retention rate after aging is CD2; The value of MD1 is 0.88 - 0.96; The value of CD1 is 0.82 - 0.92; The ratio of MD1 to MD2 is 1.05:1 - 1.30:1; The ratio of CD1 to CD2 is 1.05:1 - 1.30:1; Under standard atmospheric conditions, the transverse and longitudinal tensile strengths of the same specimen before and after wetting are measured respectively. The longitudinal wet tensile strength retention rate is the ratio of the longitudinal tensile strength after wetting to the longitudinal tensile strength before wetting, and the transverse wet tensile strength retention rate is the ratio of the transverse tensile strength after wetting to the longitudinal and transverse tensile strength before wetting; the wetting process conditions of the specimen are: the wetting water temperature is 40°C, the wetting time is 8 hours, the constant-speed stretching rate is 50 mm / min, and the relative humidity of the environment during testing is 48 - 52%RH; Aging treatment: the irradiance in the wavelength range of 300 - 400 nm is 60 ± 2 w / m 2 , the black label temperature is 65 ± 2 °C, the air temperature in the test chamber is 38 ± 3 °C, the relative humidity is 50 ± 10%, and the drying time is 672 hours; For the composite sheet described above, its raw materials also include modified chlorinated polypropylene; The modified chlorinated polypropylene is a modified product obtained by adsorbing barium sulfate and silver oxide on the basis of chlorinated polypropylene; the mass fraction of the modified chlorinated polypropylene in the mixture of polyethylene and chlorinated polypropylene is 1.5 - 2.5%; The processing method of the composite sheet described above includes the following steps: (1) Prepare the spinning solution The spinning solution includes a polymer and a spinning solvent; The mass fraction of the polymer in the spinning solution is 13 - 15%; The polymer includes polyethylene and modified chlorinated polypropylene; The mass fraction of the modified chlorinated polypropylene in the polymer is 1.5 - 2.5%; The preparation method of the modified chlorinated polypropylene includes the following steps: First, disperse chlorinated polypropylene in concentrated sulfuric acid and conduct heat treatment at 105 - 110°C for 0.5 - 1.5 hours, then filter and dry to obtain sulfonated chlorinated polypropylene; second, add the sulfonated chlorinated polypropylene into the barium chloride solution by means of microwave stirring to obtain chlorinated polypropylene - barium sulfate; finally, add chlorinated polypropylene - barium sulfate into the silver nitrate solution so that silver ions are adsorbed on chlorinated polypropylene - barium sulfate to obtain the modified chlorinated polypropylene; (2) Flash spinning process Then carry out flash spinning, the spinning temperature is 180 - 208°C to obtain flash spun fibers, and then through hot pressing and calendering of the roller, the calendering temperature is 113 - 127°C, the linear pressure of calendering is 9 - 30 N / mm, and finally wind and roll up to obtain the flash spun composite sheet.

2. The composite sheet according to claim 1, characterized in that, The value of MD1 of the opaque composite sheet of the composite sheet is 0.88 - 0.

92.

3. A composite sheet according to claim 1, characterized in that, The value of MD1 of the composite sheet is 0.92 - 0.

96.

4. A composite sheet according to claim 1, characterized in that, The value of CD1 of the composite sheet is 0.82 - 0.

87.

5. A composite sheet according to claim 1, characterized in that, The value of CD1 of the composite sheet is 0.87 - 0.

92.

6. A composite sheet according to claim 1, characterized in that, The ratio of MD1 to MD2 of the composite sheet is 1.1:1 - 1.15:

1.

7. A composite sheet according to claim 1, characterized in that, The ratio of MD1 to MD2 of the composite sheet is 1.15:1 - 1.2:

1.

8. A composite sheet according to claim 1, wherein, The ratio of MD1 to MD2 of the composite sheet is 1.2:1 to 1.25:

1.

9. A composite sheet according to claim 1, characterized in that, The ratio of CD1 to CD2 of the composite sheet is 1.1:1 to 1.15:

1.

10. A composite sheet according to claim 1, wherein, The ratio of CD1 to CD2 of the composite sheet is 1.15:1 to 1.2:

1.

11. A composite sheet according to claim 1, characterized in that, The ratio of CD1 to CD2 of the composite sheet is 1.2:1 to 1.25:

1.

12. A composite sheet according to claim 1, characterized in that, The ratio of MD1 to CD1 of the composite sheet is 1.03:1 to 1.2:

1.

13. A composite sheet according to claim 12, wherein, The ratio of MD1 to CD1 of the composite sheet is 1.06:1 to 1.1:

1.

14. A composite sheet according to claim 12, characterized in that, The ratio of MD1 to CD1 of the composite sheet is 1.1:1 to 1.2:

1.

15. A composite sheet according to claim 1, characterized in that, The ratio of MD2 to CD2 of the composite sheet is 1.03:1 to 1.2:

1.

16. A composite sheet according to claim 15, wherein, The ratio of MD2 to CD2 of the composite sheet is 1.06:1 to 1.1:

1.

17. A composite sheet according to claim 15, characterized in that, The ratio of MD2 to CD2 of the composite sheet is 1.1:1 to 1.2:1.