Composite latex for chemical protective gloves, preparation method and application thereof

Abstract

The application discloses a composite latex for chemical protective gloves, a preparation method and application, and the composite latex comprises butyl latex, hydrogenated butyl nitrile rubber latex, potassium laurate, modified white carbon black, accelerator PX, accelerator ZDC, sulfur, zinc oxide, N, N-dibenzyl dodecylamine and antioxidant DBH. The modified white carbon black is prepared by the following method: placing nano SiO2 powder on a tray, drying and reserving; taking deionized water, adding the dried nano SiO2, adding DTDP (3,3'-dithiodipropionic acid) powder, stirring until dissolved; adding TISAB buffer solution dropwise to adjust the pH of the solution, and uniformly stirring to obtain silica sol; dialysis, soaking to remove small molecular substances, concentration, sieving, and obtaining the modified white carbon black. The composite latex has the advantages of high elongation at break and tear strength, good acid and alkali resistance, scratch resistance and antibacterial performance, and can be applied to the field of chemical protective gloves.

Description

Technical Field

[0001] This invention relates to the field of special gloves technology, and in particular to a composite latex for chemical protective gloves, its preparation method, and its application. Background Technology

[0002] Butyl latex is a copolymer emulsion of isobutylene and a small amount of isoprene. The dense packing of methyl groups on its main chain restricts molecular chain movement, resulting in extremely low gas permeability (less than 1 / 8 that of natural rubber), excellent ozone resistance, aging resistance, and chemical corrosion resistance. It is an ideal material for manufacturing protective gloves against toxic substances and chemicals, medical gloves, and airtight seals. However, due to the high flexibility of the butyl rubber main chain and the low cross-linking between molecular chains, the tear strength of unreinforced butyl latex films is only 15-18 kN / m, which is insufficient to meet the mechanical performance requirements of special gloves under complex working conditions.

[0003] To address the mechanical shortcomings of butyl rubber, existing technologies propose modifying it with hydrogenated nitrile butadiene rubber (HNBR). While HNBR possesses excellent mechanical strength and chemical resistance, it is a polar rubber; butyl rubber, on the other hand, is a non-polar rubber. The significant difference in polarity between the two leads to poor interfacial compatibility during direct blending. Furthermore, the rigid phase of HNBR restricts the extension of butyl rubber molecular chains, resulting in a significant decrease in the elongation at break of the blended film. This leads to reduced glove flexibility, increased susceptibility to cracking, and a substantial reduction in elongation at break.

[0004] Butyl rubber materials with low tear strength are easily torn, especially in complex chemical environments where gloves can be slightly scratched by edges, burrs, and particles, creating tiny scratches and cuts that are difficult to detect with the naked eye. Many gloves may appear intact, but already have tiny gaps; repeated bending of the hand, particularly at the base of the glove, can cause these small defects to rapidly expand and eventually tear, rendering them ineffective.

[0005] Thick gloves are not suitable for use in acidic or alkaline environments that require delicate movements, especially latex gloves with a thickness of less than 1 mm. It is difficult to meet the requirements of high tear strength, good acid and alkali resistance, high elongation at break, scratch resistance and good softness at the same time.

[0006] Therefore, developing a composite latex for chemical protective gloves that combines high tear strength, high acid and alkali immersion retention rate, scratch resistance, good crack propagation delay performance, and high softness is of great practical significance for the field of chemical protective gloves. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides a composite latex for chemical protective gloves, which has high tear strength, high acid and alkali immersion retention rate, scratch resistance, good crack propagation delay performance and high softness, making it suitable for use as a material for chemical protective gloves.

[0008] Furthermore, the present invention also provides a method for preparing chemical protective gloves using the above-mentioned composite latex.

[0009] A composite latex for use in chemical protective gloves comprises the following components by weight:

[0010] Butyl latex: 100 parts;

[0011] Hydrogenated nitrile butadiene rubber latex: 5-10 parts;

[0012] Potassium laurate: 0.1 parts;

[0013] Modified silica: 0.1-1 part;

[0014] Accelerator PX: 1-3 parts;

[0015] Accelerator ZDC: 4.8-6 parts;

[0016] Sulfur: 1-3 parts;

[0017] Zinc oxide: 4-5 parts;

[0018] N,N-Dibenzyldodecylamine: 0.05 parts;

[0019] Antioxidant DBH: 0.8-1.2 parts;

[0020] The modified silica is DTDP-modified silica, prepared by the following method: 100 parts by weight of nano-SiO2 powder are spread evenly on a tray and dried for later use; deionized water is added to the dried nano-SiO2 and stirred evenly; 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder is added and stirred until dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and stirred evenly to obtain silica sol; the silica sol is placed in a dialysis bag and sealed, soaked to remove water-soluble small molecules, concentrated under reduced pressure to form powder, and sieved through a 200-mesh sieve to obtain modified silica.

[0021] A method for preparing the above-mentioned composite latex for chemical protective gloves includes the following steps:

[0022] Step 1, Preparation of potassium laurate solution;

[0023] Step 2, Polar modification of butyl latex: Stir the butyl latex and slowly add 70% of the potassium laurate solution prepared in Step 1, stirring until homogeneous;

[0024] Step 3, Pre-dispersion of hydrogenated nitrile butadiene latex: Stir the hydrogenated nitrile butadiene latex at 80-100 r / min at room temperature, add the remaining potassium laurate solution, and stir evenly to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0025] Step 4, Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0026] The pre-stabilized hydrogenated nitrile latex from step 3 is slowly added to the polar-modified butyl latex from step 2 and stirred until homogeneous, so that the hydrogenated nitrile is uniformly dispersed in the butyl matrix.

[0027] Step 5, Preparation of modified silica: 100 parts by weight of nano-SiO2 powder is dried and set aside; deionized water is added to the dried nano-SiO2 and stirred evenly; 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder is added and stirred until dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and stirred evenly to obtain silica sol; the silica sol is placed in a dialysis bag and sealed, soaked to remove water-soluble small molecules, concentrated under reduced pressure to form powder, and sieved through a 200-mesh sieve to obtain modified silica;

[0028] Step 6, Addition of modified silica and accelerator: Slowly add the modified silica prepared in step 5 to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then add sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH, and stir to obtain a uniform composite latex.

[0029] The specific steps for preparing the potassium laurate solution in step 1 are as follows: potassium laurate is added to deionized water and stirred at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution.

[0030] The specific steps of step 2, butyl latex polar modification, are as follows: stir the butyl latex at 60-80 r / min at room temperature, slowly add 70% of the total amount of potassium laurate solution prepared in step 1, and continue stirring for 30-40 min to allow laurate ions to be fully adsorbed on the surface of butyl latex particles.

[0031] Specifically, step 3, the pre-dispersion of hydrogenated nitrile butadiene latex, involves adding the hydrogenated nitrile butadiene latex to another mixing tank, stirring at 80-100 r / min at room temperature, adding 30% of the total amount of potassium laurate solution, and stirring for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex.

[0032] Specifically, the preparation of the butyl / hydrogenated nitrile butadiene blend latex in step 4 is as follows: the pre-stabilized hydrogenated nitrile butadiene latex in step 3 is slowly added to the polarized modified butyl latex in step 2, and the stirring speed is controlled at 100-150 r / min for 60-240 min to make the hydrogenated nitrile butadiene uniformly dispersed in the butyl matrix.

[0033] The specific preparation of modified silica in step 5 is as follows: 100 parts by weight of nano-SiO2 powder are spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours for later use; 250 parts by weight of deionized water are added to the dried nano-SiO2 and stirred evenly, then 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder are added and stirred at room temperature until completely dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and stirring is continued for 10 minutes to obtain a uniform silica sol; the silica sol is placed in a dialysis bag and sealed, immersed in deionized water, the water is changed to remove small molecules, the solution is concentrated under reduced pressure to form powder, and sieved through a 200-mesh sieve to obtain modified silica.

[0034] Specifically, the addition of modified silica and accelerator in step 6 is as follows: the modified silica prepared in step 5 is slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, followed by the addition of sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH, and stirred for 120 minutes to obtain a uniform composite latex.

[0035] A method for preparing gloves using the composite latex obtained by the above preparation method includes an impregnation film-forming step: impregnating, vulcanizing, washing with hot water and drying the composite latex to obtain the product.

[0036] The specific process of impregnation film formation is as follows: the mold treated with composite latex is impregnated for 60-80 seconds, then lifted and dried at 75°C for 90 minutes, then placed in a high-pressure vulcanizing tank for vulcanization, and after demolding, it is washed in hot water for more than 30 minutes, and finally dried at 90°C to constant weight.

[0037] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 50-70min; and the thickness of the finished film is 0.5-0.7mm.

[0038] The butyl latex described in this invention can be commercially available butyl latex, or it can be made from the following components in parts by weight: 15 parts butyl rubber, 5 parts oleic acid, 3 parts potassium hydroxide, 1.5 parts potassium dihydrogen phosphate, 4 parts polyvinyl alcohol, 4 parts polyoxyethylene castor oil potassium soap, and 100 parts water.

[0039] The butyl latex of this invention can be prepared by the following method: Butyl rubber is subjected to thin-pass pressing treatment, and then butyl rubber sheets are added to a pulper containing petroleum ether. The pulper is started and stirred for 6 hours until the rubber sheets are completely dissolved, resulting in a uniform and stable butyl rubber paste. The mass ratio of butyl rubber sheets to petroleum ether is 15:85. Then, the butyl rubber paste is placed in an emulsification device, and 5 parts by weight of oleic acid are added for premixing for 5 minutes. Next, 3 parts by weight of potassium hydroxide, 1.5 parts by weight of potassium dihydrogen phosphate, 4 parts by weight of polyvinyl alcohol, and 4 parts by weight of polyoxyethylene castor oil potassium soap are added, followed by 100 parts by weight of water. Emulsification forms a stable butyl latex. After distillation and centrifugation, a butyl latex with a solid content of 50%-60% is prepared for use.

[0040] Compared to existing technologies, the composite latex for chemical protective gloves of the present invention and its preparation method employ potassium laurate to pre-stabilize and modify butyl latex and hydrogenated nitrile butadiene latex, respectively, to ensure uniform blending of non-polar butyl latex and polar hydrogenated nitrile butadiene latex. Simultaneously, DTDP (3,3'-dithiodipropionic acid) is used to modify silica, improving the dispersibility of fillers in the latex matrix. Furthermore, N,N-dibenzyldodecylamine and zinc oxide are used as active additives. The resulting composite latex exhibits high elongation at break and tear strength, excellent acid and alkali resistance, good softness, and high crack propagation retardation, effectively extending the service life of gloves. It also possesses scratch resistance and good antibacterial properties, making it widely applicable in the field of chemical protective gloves. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0042] The materials used in the embodiments and comparative examples described in this invention are sourced from the following sources:

[0043] Activating agent: N,N-dibenzyldodecylamine, commercially available;

[0044] Potassium laurate: Commercially available;

[0045] Butyl latex: The butyl latex is prepared by emulsification, specifically including the following steps:

[0046] First, butyl rubber is subjected to thin-pass compression molding. Then, butyl rubber sheets are added to a pulper containing petroleum ether, and the pulper is started and stirred for 6 hours until the rubber sheets are completely dissolved, resulting in a uniform and stable butyl rubber paste. The mass ratio of butyl rubber sheets to petroleum ether is 15:85. Next, the butyl rubber paste is placed in an emulsification device, and 5 parts by weight of oleic acid are added for premixing for 5 minutes. Then, 3 parts by weight of potassium hydroxide, 1.5 parts by weight of potassium dihydrogen phosphate, 4 parts by weight of polyvinyl alcohol, and 4 parts by weight of polyoxyethylene castor oil potassium soap are added, followed by 100 parts by weight of water. Emulsification forms a stable butyl latex. After distillation and centrifugation, a butyl latex with a solid content of 50%-60% is prepared for use.

[0047] The butyl rubber was purchased from Panjin Xinhui New Material Co., Ltd. as dry rubber of grade 432. The analytical test results were as follows: Mooney viscosity of raw rubber, ML(1+8) 125℃: 42; volatile matter (mass fraction) %: 0.10; ash content (mass fraction) %: not detected; unsaturation: 1.79%;

[0048] Among them, the polyoxyethylene castor oil potassium soap is a mixture of polyoxyethylene castor oil and potassium hydroxide aqueous solution. It is obtained by mixing 100 parts by weight of polyoxyethylene castor oil and 24 parts by weight of 25wt% potassium hydroxide aqueous solution, heating and dissolving. The mass of polyoxyethylene castor oil potassium soap is based on the total mass of the dry polyoxyethylene castor oil and potassium hydroxide.

[0049] Polyoxyethylene castor oil: BY-3, purchased from Nanjing Taihua Chemical Co., Ltd., batch number 2025011012.

[0050] The petroleum ether was purchased from Jinzhou Petrochemical Company, batch number 210530.

[0051] Hydrogenated nitrile butadiene rubber latex: Shanghai Xintian Rubber Co., Ltd., with a solid content of 40.93% and a degree of hydrogenation of 97.2%. The embodiments and comparative examples of this invention use hydrogenated nitrile butadiene rubber latex with a solid content of 40.93%.

[0052] Silica: Evonik Jialian Silica (Nanping) Co., Ltd., Silica content: >98%; Loss on ignition: 4.8%; pH: 6.4; Nitrogen adsorption specific surface area: 191 m² 2 / g;

[0053] Sulfur: Commercially available;

[0054] DTDP (3,3'-dithiodipropionic acid): Commercially available;

[0055] TISAB buffer solution: Add 0.5L deionized water, 25ml glacial acetic acid, 58g sodium chloride, and 12g sodium citrate (containing two molecules of water of crystallization) to a 1L beaker and stir until completely dissolved. Place the beaker in a cold water bath, slowly add 6 mol / L sodium hydroxide and shake carefully. Measure the pH with a pH meter to ensure it is between 5.0 and 5.5. Cool to room temperature, transfer to a 1000ml volumetric flask, dilute to the mark with deionized water, and shake thoroughly to obtain the solution.

[0056] Accelerator ZDC: Zinc diethyldithiocarbamate, commercially available;

[0057] Accelerator PX: Zinc N-ethyl-N-phenyl dithiocarbamate, commercially available;

[0058] Antioxidant DBH: 1,4-Dibenzyloxybenzene, commercially available;

[0059] The remaining substances are commercially available.

[0060] Example 1

[0061] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0062] Step 1

[0063] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0064] Step 2

[0065] Polar modification of butyl latex: Stir the butyl latex at 70 r / min at room temperature, slowly add the potassium laurate solution prepared in step 1 (70% of the total potassium laurate), and continue stirring for 35 min to allow the laurate ions to be fully adsorbed on the surface of the butyl latex particles.

[0066] Step 3

[0067] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 100 r / min at room temperature, add the remaining potassium laurate solution (30% of the total potassium laurate), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0068] Step 4

[0069] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0070] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 100 r / min and stirred for 240 min to ensure that the hydrogenated nitrile butadiene is uniformly dispersed in the butyl matrix.

[0071] Step 5: Preparation of modified silica (DTDP modified silica):

[0072] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0073] Step 6: Addition of modified silica and accelerator:

[0074] The modified silica prepared in step 5 was slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0075] Step 7: Impregnation to form a film

[0076] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0077] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0078] Example 2

[0079] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0080] Step 1

[0081] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0082] Step 2

[0083] Polar modification of butyl latex: Stir the butyl latex at 60 r / min at room temperature, slowly add the potassium laurate solution prepared in step 1 (70% of the total potassium laurate), and continue stirring for 40 min to allow the laurate ions to be fully adsorbed on the surface of the butyl latex particles.

[0084] Step 3

[0085] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 90 r / min at room temperature, add the remaining potassium laurate solution (30% of the total potassium laurate), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0086] Step 4

[0087] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0088] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 150 r / min and stirred for 60 min to make the hydrogenated nitrile butadiene uniformly dispersed in the butyl matrix.

[0089] Step 5:

[0090] Preparation of modified silica (DTDP modified silica):

[0091] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0092] Step 6: Addition of modified silica and accelerator:

[0093] The modified silica prepared in step 5 was slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0094] Step 7: Impregnation to form a film

[0095] The composite latex is immersed in the treated mold for 60-80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0096] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 50min; finished film thickness is 0.5-0.7mm.

[0097] Example 3

[0098] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0099] Step 1

[0100] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0101] Step 2

[0102] Polar modification of butyl latex: Stir the butyl latex at 80 r / min at room temperature, slowly add the potassium laurate solution prepared in step 1 (70% of the total potassium laurate), and continue stirring for 30 min to allow the laurate ions to be fully adsorbed on the surface of the butyl latex particles.

[0103] Step 3

[0104] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 80 r / min at room temperature, add the remaining potassium laurate solution (30% of the total potassium laurate), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0105] Step 4

[0106] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0107] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 125 r / min and stirred for 150 min to make the hydrogenated nitrile butadiene uniformly dispersed in the butyl matrix.

[0108] Step 5:

[0109] Preparation of modified silica (DTDP modified silica):

[0110] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0111] Step 6: Addition of modified silica and accelerator:

[0112] The modified silica prepared in step 5 was slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0113] Step 7: Impregnation to form a film

[0114] The composite latex is immersed in the treated mold for 60-80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0115] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 70min; finished film thickness is 0.5-0.7mm.

[0116] Comparative Example 1

[0117] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0118] Step 1

[0119] Preparation of potassium chloride solution: Add potassium chloride to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium chloride aqueous solution for later use;

[0120] Step 2

[0121] Polar modification of butyl latex: Stir the butyl latex at 70 r / min at room temperature, slowly add the potassium chloride solution prepared in step 1 (70% of the total potassium chloride), and continue stirring for 35 min to allow chloride ions to be fully adsorbed on the surface of butyl latex particles.

[0122] Step 3

[0123] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 100 r / min at room temperature, add the remaining potassium chloride solution (30% of the total potassium chloride), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0124] Step 4

[0125] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0126] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 100 r / min and stirred for 240 min to ensure that the hydrogenated nitrile butadiene is uniformly dispersed in the butyl matrix.

[0127] Step 5:

[0128] Preparation of modified silica (DTDP modified silica):

[0129] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0130] Step 6: Addition of modified silica and accelerator:

[0131] The modified silica prepared in step 5 was slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0132] Step 7: Impregnation to form a film

[0133] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0134] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0135] Comparative Example 2

[0136] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0137] Step 1

[0138] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0139] Hydrogenated nitrile butadiene latex was slowly added to butyl latex, and the stirring speed was controlled at 100 r / min for 240 min to ensure that the hydrogenated nitrile butadiene was evenly dispersed in the butyl matrix.

[0140] Step 2:

[0141] Preparation of modified silica (DTDP modified silica):

[0142] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0143] Step 3: Addition of modified silica and accelerator:

[0144] The modified silica prepared in step 2 was slowly added to the butyl / hydrogenated nitrile blend latex in step 1, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0145] Step 4: Impregnation to form a film

[0146] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0147] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0148] Comparative Example 3

[0149] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0150] Step 1

[0151] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0152] Step 2

[0153] Polar modification of butyl latex: Stir the butyl latex at 70 r / min at room temperature, slowly add the potassium laurate solution prepared in step 1 (70% of the total potassium laurate), and continue stirring for 35 min to allow the laurate ions to be fully adsorbed on the surface of the butyl latex particles.

[0154] Step 3

[0155] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 100 r / min at room temperature, add the remaining potassium laurate solution (30% of the total potassium laurate), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0156] Step 4

[0157] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0158] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 100 r / min and stirred for 240 min to ensure that the hydrogenated nitrile butadiene is uniformly dispersed in the butyl matrix.

[0159] Step 5

[0160] Addition of silica to ingredients:

[0161] Slowly add silica to the butyl / hydrogenated nitrile blend latex from step 4, then add sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH and stir for 120 minutes to obtain a uniform composite latex.

[0162] Step 6: Impregnation to form a film

[0163] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0164] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0165] Comparative Example 4

[0166] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0167] Step 1

[0168] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0169] Step 2

[0170] Polar modification of butyl latex: Stir the butyl latex at 70 r / min at room temperature, slowly add the potassium laurate solution prepared in step 1 (70% of the total potassium laurate), and continue stirring for 35 min to allow the laurate ions to be fully adsorbed on the surface of the butyl latex particles.

[0171] Step 3

[0172] Pre-dispersion of hydrogenated nitrile butadiene latex: Add hydrogenated nitrile butadiene latex to another mixing tank, stir at 100 r / min at room temperature, add the remaining potassium laurate solution (30% of the total potassium laurate), stir for 20 min to obtain pre-stabilized hydrogenated nitrile butadiene latex;

[0173] Step 4

[0174] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0175] The hydrogenated nitrile butadiene latex pre-stabilized in step 3 is slowly added to the polar modified butyl latex in step 2. The stirring speed is controlled at 100 r / min and stirred for 240 min to ensure that the hydrogenated nitrile butadiene is uniformly dispersed in the butyl matrix.

[0176] Step 5:

[0177] Preparation of modified silica (DTDP modified silica):

[0178] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0179] Step 6: Addition of modified silica and accelerator:

[0180] The modified silica prepared in step 5 was slowly added to the butyl / hydrogenated nitrile blend latex in step 4, and then sulfur, zinc oxide, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0181] Step 7: Impregnation to form a film

[0182] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0183] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0184] Comparative Example 5

[0185] Prepare the raw materials as shown in Table 1, and prepare the composite latex according to the following method:

[0186] Step 1

[0187] Preparation of potassium laurate solution: Add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution for later use;

[0188] Step 2

[0189] Polar modification of butyl latex: Stir butyl latex at 70 r / min at room temperature, slowly add potassium laurate solution prepared in step 1, and continue stirring for 35 min to allow laurate ions to be fully adsorbed on the surface of butyl latex particles.

[0190] Step 3

[0191] Preparation of butyl / hydrogenated nitrile butadiene blend latex:

[0192] Hydrogenated nitrile butadiene latex was slowly added to the polar modified butyl latex in step 2, and the stirring speed was controlled at 100 r / min for 240 min to make the hydrogenated nitrile butadiene uniformly dispersed in the butyl matrix.

[0193] Step 4:

[0194] Preparation of modified silica (DTDP modified silica):

[0195] 100 parts by weight of nano-SiO2 powder were spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours. 250 parts by weight of deionized water were added to the dried nano-SiO2 and stirred evenly. Then, 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder were added and stirred at room temperature until completely dissolved. TISAB buffer solution was added dropwise to adjust the pH of the solution to 5.0, and stirring was continued for 10 minutes to obtain a uniform silica sol. The silica sol was placed in a dialysis bag, sealed, and immersed in deionized water. The water was changed to remove small molecules, and the solution was concentrated under reduced pressure to form powder. The powder was then sieved through a 200-mesh sieve to obtain modified silica.

[0196] Step 5: Addition of modified silica and accelerator:

[0197] The modified silica prepared in step 4 was slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 3, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH were added and stirred for 120 min to obtain a uniform composite latex.

[0198] Step 6: Impregnation to form a film

[0199] The composite latex is immersed in the treated mold for 80 seconds, then lifted and dried at 75°C for 90 minutes. It is then placed in a high-pressure vulcanizing tank for vulcanization. After demolding, it is washed in hot water for more than 30 minutes and finally dried at 90°C to constant weight.

[0200] The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 60min; finished film thickness is 0.5-0.7mm.

[0201] Table 1. Bill of materials for the examples and comparative examples (unit: parts by weight)

[0202] Butyl latex 100 100 100 100 100 100 100 100 Hydrogenated nitrile rubber latex 7.5 5 10 7.5 7.5 7.5 7.5 7.5 Potassium laurate 0.1 0.1 0.1 / / 0.1 0.1 0.1 Potassium chloride / / / 0.1 / / / / Modified silica 0.5 1 0.1 0.5 0.5 / 0.5 0.5 precipitate / / / / / 0.5 / / Sulfur 2 3 1 2 2 2 2 2 Zinc oxide 4.5 5 4 4.5 4.5 4.5 4.55 4.5 N,N-Dibenzyldodecylamine 0.05 0.05 0.05 0.05 0.05 0.05 / 0.05 Accelerator ZDC 5 6 4.8 5 5 5 5 5 Accelerator PX 1 2 3 1 1 1 1 1 Anti-aging agent DBH 1 0.8 1.2 1 1 1 1 1

[0203] The rubber gloves prepared in the examples and comparative examples were subjected to the following tests, and the results are listed in Table 2:

[0204] Tear strength (N / mm): Refer to GB / T529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber", use a right-angled specimen without a cut, cut the specimen directly from the finished glove film, the actual thickness of the specimen is 0.5-0.7mm of the product thickness, and the tensile speed is 500mm / min.

[0205] Elongation at break (%): Refer to GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", dumbbell specimens are used, the specimens are taken from the glove film, the specimen thickness is 0.5-0.7 mm of the actual thickness of the product, three samples are taken for each group, and the average value is taken.

[0206] Alkali washing elongation at break: Soak the gloves in a 40% sodium hydroxide aqueous solution for 48 hours, dry them at low temperature, and then test the elongation at break according to the above method (GB / T528-2009). Take three samples from each group for testing, and take the average value to obtain the alkali washing elongation at break.

[0207] Pickling elongation at break: Immerse the gloves in 68% sulfuric acid solution for 48 hours, dry at low temperature, and then test the elongation at break according to the above method (GB / T528-2009). Take three samples for each group and take the average value of the three tests to obtain the pickling elongation at break.

[0208] Elongation stress (MPa): Refer to GB / T528-2009 and record the stress at 500% elongation; the lower the elongation stress, the softer the material and the more suitable it is as a glove material;

[0209] Performance in delaying crack propagation: Samples were taken from the glove film, with a thickness of 0.5-0.7 mm (the actual thickness of the product), measuring 100 mm (length) × 15 mm (width). A brand-new, sharp, single-edged safety blade was used, perpendicular to the sample surface. Using the blade's own weight, an initial cut perpendicular to the long side was made at the geometric center of the sample's long side, penetrating the entire sample thickness. A 3 mm initial cut was made on the sample. A thin film reciprocating bending tester was used, with a bending radius of 2 mm, a bending angle of 0-135°, and a bending frequency of 30 times / min, completing 3000 reciprocating bending cycles. After the test, the final total crack length was measured using a microscope, and the crack growth length (mm) was calculated as: Crack growth length = Total crack length after bending - Initial cut length measured before the test. Five samples were taken from each group, and the average value was taken.

[0210] Scratch resistance: Φ0.5mm hard steel ball, load 1.5N, 200 reciprocating scratches; micro-cracks observed with a magnifying glass, strength retention rate measured after scratching; the entire scratch trajectory area observed with a 10x magnifying glass, recording the presence of shallow indentations, fine cracks, and continuous micro-cracks, strength retention rate measured after scratching, strength retention rate after scratching (%) = (tear strength after scratching ÷ initial tear strength) × 100%;

[0211] Antibacterial properties: Referring to JISZ 2801-2010 "Antibacterial processed products - Test methods and antibacterial effects", the test strain used was the standard strain Staphylococcus aureus ATCC6538; 50mm×50mm samples were cut from the finished gloves, and the sample thickness was 0.5-0.7mm of the actual product thickness; a film contact test was conducted at 37℃ and relative humidity >90%, and the antibacterial rate (%) of the sample was calculated.

[0212] Table 2 Performance Tests of the Examples and Comparative Gloves

[0213] Tear strength (N / mm) 21.35 20.89 20.07 15.5 14.49 16.53 16.76 15.65 Elongation at break (%) 720 718 709 592 575 650 637 608 Elongation at break after pickling (%) 612 615 606 495 464 547 530 510 Alkali washing elongation at break 573 560 562 423 401 457 435 426 Elongation stress (MPa) 1.36 1.38 1.40 2.19 2.29 2.35 2.25 2.07 Crack growth length (mm) 0.89 0.95 0.98 2.45 2.88 3.20 2.96 2.67 Surface cracks after scratching There are indentations, but no cracks. There are indentations, but no cracks. There are indentations, but no cracks. There are tiny cracks There are tiny cracks There are tiny cracks There are tiny cracks There are continuous cracks Strength retention rate after scratching (%) 88 85 82 68 63 58 59 54 Antibacterial activity (%) 99.9 99.8 99.9 99.8 90.8 75.4 99.8 89.5

[0214] As can be seen from the above data, Examples 1-3 are samples prepared under the limited formulation and complete process of this invention. Potassium laurate was used to pre-stabilize the butyl latex and hydrogenated nitrile latex, respectively. DTDP-modified silica was used for reinforcement, and the modified filler was relatively uniformly dispersed in the rubber matrix. N,N-dibenzyldodecylamine and zinc oxide were used as active additives, which can effectively promote the vulcanization accelerator to exert its effect, thereby reducing the amount of accelerator or shortening the vulcanization time, improving the performance of the vulcanized rubber, and obtaining a composite film with excellent comprehensive performance and a thickness of 0.5-0.7 mm.

[0215] The tear strength of the samples in this invention reaches 20.07-21.35 N / mm, and the initial elongation at break is maintained at 709%-720%, exhibiting both high tear strength and large elongation at break, which can meet the basic mechanical requirements of chemical gloves during wearing and tensile deformation. After static immersion in 68% sulfuric acid and 40% sodium hydroxide solutions for 48 hours respectively, the elongation at break after acid washing remains at 606%-615%, and after alkali washing, it remains at 560%-573%, showing a high level of mechanical property retention. This indicates that the composite film of this invention can still maintain good elasticity and mechanical properties under strong acid and alkali immersion environments, making it suitable for protective use in acid and alkali conditions. Meanwhile, the 500% elongation stress of the sample is 1.36-1.40 MPa, indicating that the material is soft and suitable for glove manufacturing.

[0216] In the reciprocating bending test of the rubber glove samples prepared by this invention with an initial 3.0mm cut, the tear growth length of the example samples was only 0.89-0.98mm, indicating a small increase in tear size. This demonstrates that the formulation system of this invention can effectively delay the further expansion of existing micro-tears, reducing the risk of premature tearing and hole formation in the gloves due to the continuous expansion of micro-defects. Regarding scratch resistance, the example samples showed only shallow indentations after scratching, without cracks, and the tear strength retention rate after scratching reached over 82%, indicating good scratch resistance. The antibacterial performance test results showed that the example samples achieved an antibacterial rate of over 99.7%, and the adhesive film also possessed excellent antibacterial effects.

[0217] In Comparative Example 1, potassium laurate was replaced with potassium chloride. Potassium chloride could not effectively modify the polarity of the latex particle surface, resulting in poor compatibility between the two phases, a significant decline in the overall mechanical properties of the material, a decrease in tear strength, and a significant increase in the decrease in elongation at break after acid and alkali soaking.

[0218] Comparative Example 2 omitted the phase separation pre-stabilization process and directly blended the two latexes. Lacking the surface adsorption modification of latex particles, the two phases were poorly dispersed, with a tear strength of only 14.49 N / mm and an initial elongation of only 575%. The performance deteriorated significantly after acid and alkali immersion, and its crack retardation and scratch resistance were significantly inferior to those of the Example.

[0219] Comparative Example 3 used unmodified ordinary silica. Ordinary silica has strong silanol hydroxyl groups on its surface, resulting in weak interfacial bonding with the rubber matrix, easy filler agglomeration, and insufficient reinforcing effect. Comparative Example 4 replaced it with zinc oxide, a traditional active additive in the art. Although its tear and antibacterial properties were acceptable, its initial elongation and elongation after acid and alkali immersion were significantly lower than those of the embodiments of this invention. Comparative Example 5 eliminated the separate pre-dispersion step of hydrogenated nitrile butadiene latex, adding all potassium laurate to the butyl latex at once. The hydrogenated nitrile butadiene latex lacked surfactant pre-stabilization, resulting in insufficient interfacial modification. The test results showed that the overall mechanical properties of Comparative Examples 3-5 were significantly inferior to the embodiments, and their acid and alkali resistance, crack retardation performance, and scratch resistance were also significantly inferior to the embodiments.

[0220] In summary, the composite latex prepared by the technical solution of the present invention has advantages such as good mechanical properties, good acid and alkali resistance, good softness, good crack growth retardation performance and good scratch resistance, and can be widely used in chemical protective glove materials.

[0221] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite latex for use in chemical protective gloves, characterized in that... It comprises the following components by weight: Butyl latex: 100 parts; Hydrogenated nitrile butadiene rubber latex: 5-10 parts; Potassium laurate: 0.1 parts; Modified silica: 0.1-1 part; Accelerator PX: 1-3 parts; Accelerator ZDC: 4.8-6 parts; Sulfur: 1-3 parts; Zinc oxide: 4-5 parts; N,N-Dibenzyldodecylamine: 0.05 parts; Antioxidant DBH: 0.8-1.2 parts; The modified silica is DTDP-modified silica, prepared by the following method: 100 parts by weight of nano-SiO2 powder are spread evenly on a tray and dried for later use; deionized water is taken, the dried nano-SiO2 is added, and 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder is added and stirred until dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and the mixture is stirred evenly to obtain silica sol; the silica sol is placed in a dialysis bag and sealed, soaked to remove water-soluble small molecules, concentrated under reduced pressure to obtain powder, and sieved through a 200-mesh sieve to obtain modified silica.

2. A method for preparing the composite latex for chemical protective gloves according to claim 1, characterized in that... Includes the following steps: Step 1, Preparation of potassium laurate solution; Step 2, Polar modification of butyl latex: Stir the butyl latex and slowly add 70% of the potassium laurate solution prepared in Step 1, stirring until homogeneous; Step 3, Pre-dispersion of hydrogenated nitrile butadiene latex: Stir the hydrogenated nitrile butadiene latex at 80-100 r / min at room temperature, add the remaining potassium laurate solution, and stir evenly to obtain pre-stabilized hydrogenated nitrile butadiene latex; Step 4, Preparation of butyl / hydrogenated nitrile butadiene blend latex: The pre-stabilized hydrogenated nitrile latex from step 3 is slowly added to the polar-modified butyl latex from step 2 and stirred until homogeneous, so that the hydrogenated nitrile is uniformly dispersed in the butyl matrix. Step 5, Preparation of modified silica: 100 parts by weight of nano-SiO2 powder is dried and set aside; deionized water is added to the dried nano-SiO2, and 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder is added and stirred until dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and stirred evenly to obtain silica sol; the silica sol is placed in a dialysis bag and sealed, soaked to remove water-soluble small molecules, concentrated under reduced pressure to form powder, and sieved through a 200-mesh sieve to obtain modified silica; Step 6, Addition of modified silica and accelerator: Slowly add the modified silica prepared in step 5 to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then add sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH and stir to obtain a uniform composite latex.

3. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The specific steps for preparing the potassium laurate solution in step 1 are as follows: add potassium laurate to deionized water and stir at 50-60℃ until completely dissolved to prepare a 10% potassium laurate aqueous solution.

4. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The specific steps of step 2, butyl latex polarity modification, are as follows: at room temperature, stir the butyl latex at 60-80 r / min, slowly add 70% of the total amount of potassium laurate solution prepared in step 1, and continue stirring for 30-40 min to allow laurate ions to be fully adsorbed on the surface of the butyl latex particles.

5. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The specific steps of step 3, pre-dispersion of hydrogenated nitrile butadiene latex, are as follows: add hydrogenated nitrile butadiene latex to another mixing tank, stir at 80-100 r / min at room temperature, add 30% of the total amount of potassium laurate solution, stir for 20 min, and obtain pre-stabilized hydrogenated nitrile butadiene latex.

6. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The preparation of the butyl / hydrogenated nitrile butadiene blend latex in step 4 is specifically as follows: the pre-stabilized hydrogenated nitrile butadiene latex in step 3 is slowly added to the polar modified butyl latex in step 2, and the stirring speed is controlled at 100-150 r / min for 60-240 min to make the hydrogenated nitrile butadiene uniformly dispersed in the butyl matrix.

7. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The specific preparation of modified silica in step 5 is as follows: 100 parts by weight of nano-SiO2 powder are spread evenly on a tray and dried in a vacuum oven at 120℃ for 12 hours for later use; 250 parts by weight of deionized water are added to the dried nano-SiO2 and stirred evenly, then 5 parts by weight of DTDP (3,3'-dithiodipropionic acid) powder are added and stirred at room temperature until completely dissolved; TISAB buffer solution is added dropwise to adjust the pH of the solution to 5.0, and stirring is continued for 10 minutes to obtain a uniform silica sol; the silica sol is placed in a dialysis bag and sealed, immersed in deionized water, the water is changed to remove small molecules, and the solution is concentrated under reduced pressure to form powder, which is then sieved through a 200-mesh sieve to obtain modified silica.

8. The method for preparing the composite latex for chemical protective gloves as described in claim 2, characterized in that: The specific steps for adding modified silica and accelerator in step 6 are as follows: the modified silica prepared in step 5 is slowly added to the butyl / hydrogenated nitrile butadiene blend latex in step 4, and then sulfur, zinc oxide, N,N-dibenzyldodecylamine, accelerator PX, accelerator ZDC and antioxidant DBH are added and stirred for 120 min to obtain a uniform composite latex.

9. A method for preparing gloves using the composite latex obtained by the preparation method according to any one of claims 2-8, characterized in that: The process includes an impregnation and film-forming step: impregnating the composite latex, vulcanizing, washing with hot water, and drying to obtain the product.

10. The method for preparing gloves using the composite latex as described in claim 9, characterized in that: The specific process of impregnation film formation is as follows: the composite latex is impregnated in the treated mold for 60-80 seconds, then lifted and dried at 75°C for 90 minutes, then placed in a high-pressure vulcanizing tank for vulcanization, and after demolding, it is washed in hot water for more than 30 minutes, and finally dried at 90°C to constant weight. The vulcanization conditions are as follows: vulcanization temperature 120℃, vulcanization gas pressure 0.2-0.3MPa, vulcanization time 50-70min; finished film thickness is 0.5-0.7mm.