Carboxylic butadiene-acrylonitrile latex for gloves with high tensile strength and high stress retention rate and preparation method of carboxylic butadiene-acrylonitrile latex

Abstract

The invention relates to carboxylic butadiene-acrylonitrile latex for gloves with high tensile strength and high stress retention rate and a preparation method of the carboxylic butadiene-acrylonitrile latex. The latex is formed by compounding a polymer microparticle dispersion liquid A and a polymer microparticle dispersion liquid B according to a certain proportion, specifically, the polymer microparticle dispersion liquid A is prepared from 1, 3-butadiene, acrylonitrile and methacrylic acid monomers through an emulsion copolymerization method in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and the polymer microparticle dispersion liquid B is prepared from 1, 3-butadiene, acrylonitrile and methacrylic acid monomers. And defoaming, removing residual monomers, concentrating, and adjusting the pH value to finally obtain the product. The polymer microparticle dispersion liquid B is prepared from 1, 3-butadiene, acrylonitrile and itaconic acid monomers through an emulsion copolymerization method in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and the polymer microparticle dispersion liquid B is finally prepared through defoaming, residual monomer removal, concentration and pH adjustment; the weight ratio of acrylonitrile in the polymer microparticles of the dispersion liquid B is greater than the weight ratio of acrylonitrile in the polymer microparticles of the dispersion liquid A, and the polymer microparticle dispersion liquid A and the polymer microparticle dispersion liquid B are matched in a solid content range of 95: 5 to 40: 60 to form the carboxylic acrylonitrile-butadiene rubber latex for gloves with high tensile strength and high stress retention rate. According to the present invention, the tensile strength of the dip-molded glove product produced by using the carboxyl butyronitrile latex prepared by using the method is more than or equal to 30 MPa, the stress retention rate is more than or equal to 45%, the elongation is more than or equal to 500%, and the dip-molded glove product has characteristics of high tensile strength, high stress retention rate and good softness.

Description

Technical Field

[0001] The invention relates to the field of latex, and in particular to a carboxyl nitrile latex for gloves with high tensile strength and high stress retention rate and a preparation method thereof. Background Art

[0002] Carboxylated nitrile latex is used to make gloves. It is widely used in the medical, pharmaceutical, sanitation, beauty and hairdressing, food processing and other industries mainly because of its good friction resistance, heat resistance, oil resistance, acid and alkali resistance and puncture resistance. The strength, stress retention rate and softness of disposable nitrile gloves prepared with carboxylated nitrile latex can be adjusted by adjusting the content of acrylonitrile, methacrylic acid and butadiene. However, it is difficult for existing glove products on the market to have high tensile strength, high stress retention rate and good softness at the same time, which greatly limits its application in certain fields. Summary of the invention

[0003] The invention provides a carboxyl nitrile latex for gloves with high tensile strength and high stress retention rate and a preparation method thereof.

[0004] The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate described in the present invention is composed of a polymer microparticle dispersion A and a polymer microparticle dispersion B in a certain proportion. Specifically, the polymer microparticle dispersion A is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and methacrylic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the polymer microparticle dispersion B is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and itaconic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the weight ratio of acrylonitrile in the polymer microparticles of the dispersion B is greater than the weight ratio of acrylonitrile in the polymer microparticles of the dispersion A, and the polymer microparticle dispersion A and the polymer microparticle dispersion B are 95: The carboxyl nitrile latex for gloves with high tensile strength and high stress retention rate is formed by mixing in the range of 5 to 40:60; the high tensile strength refers to a tensile strength ≥30 MPa, and the high stress retention rate refers to a stress retention rate ≥45%.

[0005] Furthermore, the polymer microparticle dispersion A contains a copolymer in which the content of 1,3-butadiene monomer units is 70.5w%~79.5w% (weight %), the content of acrylonitrile monomer units is 25w%~13w%, and the content of methacrylic acid monomer units is 4.5w%~7.5w%; the polymer microparticle dispersion B contains a copolymer in which the content of 1,3-butadiene monomer units is 59w%~69.5w% (weight %), the content of acrylonitrile monomer units is 40w%~25.5w%, and the content of itaconic acid monomer units is 1.0w%~5.0w% polymer microparticle dispersion B.

[0006] Furthermore, the polymer microparticle dispersion A finally prepared polymer microparticles have a particle size of 85-130 nm and a pH of 7.5-9.0; the polymer microparticle dispersion B finally prepared polymer microparticles have a particle size of 80-130 nm and a pH of 7.5-9.0.

[0007] Furthermore, the water-soluble oxidant is a mixture of one or more of sodium persulfate, potassium persulfate, ammonium persulfate and hydrogen peroxide in any proportion; the usage amount of the water-soluble oxidant is 0.1 to 3.0 wt% of the total amount of monomers.

[0008] Furthermore, the chain transfer agent is a mixture of one or more of dodecyl mercaptan, tert-dodecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, and isooctyl mercaptopropionate in any proportion; the amount of the chain transfer agent used is 0.3 to 2.0 wt% of the total monomer amount.

[0009] Furthermore, the electrolyte is a mixture of one or more of disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, sodium bicarbonate, and sodium pyrophosphate in any proportion; the amount of the electrolyte used is 0.02-0.3wt% of the total monomer amount; the emulsifier is a mixture of one or more of sodium dodecylbenzene sulfonate, sodium dodecyl diphenyl ether disulfonate, and sodium polyoxyethylene alkyl ether sulfate in any proportion; the amount of the emulsifier used is 1.2-4.2wt% of the total monomer amount.

[0010] The present invention also provides the use of the carboxyl nitrile latex for gloves with high tensile strength and high stress retention rate in producing dip-molded glove products.

[0011] The carboxyl nitrile latex for gloves with high tensile strength and high stress retention rate is prepared by mixing polymer microparticle dispersion A and polymer microparticle dispersion B in a certain ratio, specifically, the polymer microparticle dispersion A and the polymer microparticle dispersion B are mixed in a solid content range of 95:5 to 40:60.

[0012] The dip-molded glove product produced by the carboxyl nitrile latex prepared by the present invention has a tensile strength of ≥30 MPa, a stress retention rate of ≥45%, and an elongation of ≥500%, and has high tensile strength, high stress retention rate and good softness. DETAILED DESCRIPTION

[0013] Below in conjunction with specific embodiment, the present invention is further described to the specific embodiment of the present invention.It should be understood that these embodiments are only used for the present invention and are not used to limit the scope of the present invention.It should be understood that after reading the content of the present invention, those skilled in the art make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0014] A carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate, characterized in that: the latex is composed of a polymer microparticle dispersion A and a polymer microparticle dispersion B in a certain proportion, specifically, the polymer microparticle dispersion A is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and methacrylic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the polymer microparticle dispersion B is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and itaconic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the weight ratio of acrylonitrile in the polymer microparticles of the dispersion B is greater than the weight ratio of acrylonitrile in the polymer microparticles of the dispersion A, and the polymer microparticle dispersion A and the polymer microparticle dispersion B are 95: The match is formed in the range of 5 to 40:60 Example 1 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 100 kg of desalted water, 15 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.4 kg of a 10 wt% aqueous solution of sodium bicarbonate, 0.3 kg of tert-dodecyl mercaptan, 22 kg of acrylonitrile, and 7.0 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 71 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 36° C., 10 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 50%, 10 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution is added, and the temperature is raised to 40° C.; when the conversion rate reaches more than 85%, the temperature is further raised to 50° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 105 nm is obtained.

[0015] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 100 kg of desalted water, 13 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.4 kg of a 10 wt% aqueous solution of sodium bicarbonate, 0.3 kg of tert-dodecyl mercaptan, 35 kg of acrylonitrile, and 20 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 63 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 40° C., 15 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 50%, 15 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution is added, and the temperature is raised to 45° C.; when the conversion rate reaches more than 88%, the temperature is further raised to 55° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 107 nm is obtained.

[0016] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 75:25 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0017] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxy nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and finally the emulsion solid content was adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 32MPa, a stress retention rate of 53%, and an elongation of 575%.

[0018] Example 2 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 105 kg of desalted water, 8 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.2 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 0.3 kg of dodecyl mercaptan, 25 kg of acrylonitrile, and 4.5 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 70.5 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 38° C., 5 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 55%, 4 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution is added, and the temperature is raised to 42° C.; when the conversion rate reaches more than 88%, the temperature is further raised to 58° C.; when the conversion rate reaches more than 95%, 0.8 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.4-8.6, and a particle size of 130 nm is obtained.

[0019] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 105 kg of desalted water, 9 kg of 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.2 kg of 10 wt% aqueous solution of sodium bicarbonate, 0.3 kg of dodecyl mercaptan, 40 kg of acrylonitrile, and 10 kg of 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 59 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 40° C., 5 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 49%, 3 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution is added, and the temperature is raised to 60° C.; when the conversion rate reaches more than 90%, the temperature is further raised to 70° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.4-8.6, and a particle size of 128 nm is obtained.

[0020] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 95:5 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0021] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanized dispersion. The dispersion was filtered through 300 meshes, and the vulcanized dispersion was slowly added to the carboxylated nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and the solid content of the emulsion was finally adjusted to 30%, and stirred for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 30 MPa, a stress retention rate of 54%, and an elongation of 570%.

[0022] Example 3 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 70 kg of desalted water, 30 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 3 kg of a 10 wt% aqueous solution of tetrasodium ethylenediaminetetraacetate, 2 kg of dodecyl mercaptan, 13 kg of acrylonitrile, and 7.5 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 79.5 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 35° C., 30 kg of a 10 wt% aqueous solution of ammonium persulfate is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 40%, 12 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate is added, and the temperature is raised to 42° C.; when the conversion rate reaches more than 83%, the temperature is further raised to 52° C.; when the conversion rate reaches more than 95%, 0.5 kg of a 5 wt% aqueous solution of sodium methylaminodithiocarbamate is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 85 nm is obtained.

[0023] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 70 kg of desalted water, 35 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 3 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 2 kg of dodecyl mercaptan, 40 kg of acrylonitrile, and 10 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 59 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 34° C., 30 kg of a 10 wt% aqueous solution of ammonium persulfate is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 50%, 7 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate is added, and the temperature is raised to 40° C.; when the conversion rate reaches more than 80%, the temperature is further raised to 48° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt% aqueous solution of sodium methylaminodithiocarbamate is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 80 nm is obtained.

[0024] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 40:60 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0025] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxylic nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and the solid content of the emulsion was finally adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 33MPa, a stress retention rate of 52%, and an elongation of 550%.

[0026] Example 4 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 100 kg of desalted water, 22 kg of 10 wt% sodium dodecyl diphenyl ether disulfonate, 0.5 kg of 10 wt% disodium ethylenediaminetetraacetic acid aqueous solution, 0.5 kg of hexadecyl mercaptan, 18 kg of acrylonitrile, and 6.5 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 75.5 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 41° C., 22 kg of a 2 wt % potassium persulfate aqueous solution is added, and the polymerization reaction begins; when the polymerization reaction conversion rate reaches 50%, 12 kg of a 10 wt % sodium dodecyl diphenyl ether disulfonate aqueous solution is added, and the temperature is raised to 45° C.; when the conversion rate reaches more than 82%, the temperature is further raised to 55° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 108 nm is obtained.

[0027] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 100 kg of desalted water, 25 kg of 10 wt% sodium dodecyl diphenyl ether disulfonate, 0.6 kg of 10 wt% sodium bicarbonate aqueous solution, 1.2 kg of dodecyl mercaptan, 38 kg of acrylonitrile, and 14 kg of 10 wt% itaconic acid aqueous solution are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 60.6 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 40° C., 30 kg of a 2 wt % potassium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 43%, 10 kg of a 10 wt % sodium dodecyl diphenyl ether disulfonate aqueous solution is added, and the temperature is raised to 48° C.; when the conversion rate reaches more than 84%, the temperature is further raised to 54° C.; when the conversion rate reaches more than 95%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 102 nm is obtained.

[0028] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 80:20 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0029] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxy nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and finally the solid content of the emulsion was adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, water washing, and vulcanization. The product had a tensile strength of 35MPa, a stress retention rate of 55%, and an elongation of 552%.

[0030] Example 5 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 90 kg of desalted water, 15 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.3 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 1.8 kg of octadecyl mercaptan, 22 kg of acrylonitrile, and 5.0 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 73.0 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 37° C., 45 kg of a 2 wt % aqueous solution of ammonium persulfate is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 42%, 10 kg of a 10 wt % aqueous solution of sodium dodecylbenzenesulfonate is added, and the temperature is raised to 45° C.; when the conversion rate reaches more than 86%, the temperature is further raised to 59° C.; when the conversion rate reaches more than 95%, 0.5 kg of a 5 wt % aqueous solution of sodium methylaminodithiocarbamate is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 115 nm is obtained.

[0031] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 80 kg of desalted water, 18 kg of a 10 wt% aqueous solution of sodium dodecyl diphenyl ether disulfonate, 0.5 kg of a 10 wt% aqueous solution of sodium bicarbonate, 1.2 kg of hexadecyl mercaptan, 35 kg of acrylonitrile, and 22 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 62.8 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 35° C., 50 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 43%, 10 kg of a 10 wt % sodium dodecyl diphenyl ether disulfonate aqueous solution is added, and the temperature is raised to 43° C.; when the conversion rate reaches more than 83%, the temperature is further raised to 52° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 113 nm is obtained.

[0032] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 70:30 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0033] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanized dispersion. The dispersion was filtered through 300 meshes, and the vulcanized dispersion was slowly added to the carboxylated nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and the solid content of the emulsion was finally adjusted to 30%, and stirred for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 34MPa, a stress retention rate of 52%, and an elongation of 565%.

[0034] Example 6 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 75 kg of desalted water, 28 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 0.8 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 0.6 kg of 2-ethylhexyl thioglycolate, 18 kg of acrylonitrile, and 6.5 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 75.5 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 43° C., 70 kg of a 2 wt % aqueous hydrogen peroxide solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 44%, 4 kg of a 10 wt % aqueous sodium dodecyl diphenyl ether disulfonate solution is added, and the temperature is raised to 48° C.; when the conversion rate reaches more than 88%, the temperature is further raised to 51° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % aqueous sodium methylaminodithiocarboxylate solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 95 nm is obtained.

[0035] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 80 kg of desalted water, 30 kg of 10 wt% sodium dodecylbenzenesulfonate aqueous solution, 1.2 kg of 10 wt% sodium bicarbonate aqueous solution, 0.8 kg of octadecyl mercaptan, 33 kg of acrylonitrile, and 40 kg of 10 wt% itaconic acid aqueous solution are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 63 g of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 44° C., 32 kg of a 2 wt % aqueous hydrogen peroxide solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 50%, 5 kg of a 10 wt % aqueous sodium dodecyl diphenyl ether disulfonate solution is added, and the temperature is raised to 48° C.; when the conversion rate reaches more than 84%, the temperature is further raised to 60° C.; when the conversion rate reaches more than 95%, 0.5 kg of a 5 wt % aqueous sodium methylaminodithiocarboxylate solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 92 nm is obtained.

[0036] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 60:40 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0037] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxylic nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and finally the emulsion solid content was adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 31MPa, a stress retention rate of 45%, and an elongation of 590%.

[0038] Example 7 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 85 kg of desalted water, 19 kg of a 10 wt% aqueous solution of sodium polyoxyethylene alkyl ether sulfate, 2.2 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 1.0 kg of 2-ethylhexyl thioglycolate, 17 kg of acrylonitrile, and 6.0 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 77.0 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature was raised to 37° C., 60 kg of 2 wt % aqueous hydrogen peroxide solution was added, and the polymerization reaction started; when the polymerization reaction conversion rate reached 41%, 10 kg of 10 wt % sodium polyoxyethylene alkyl ether sulfate solution was added, and the temperature was raised to 45° C.; when the conversion rate reached more than 88%, the temperature was further raised to 55° C.; when the conversion rate reached more than 94%, 0.5 kg of 5 wt % sodium methylaminodithiocarboxylate solution was added to stop the reaction, and ammonia water and defoaming agent were added, and then the residual monomers were removed, the mixture was concentrated, and the pH was adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 122 nm was obtained.

[0039] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 85 kg of desalted water, 18 kg of a 10 wt% aqueous solution of polyoxyethylene alkyl ether sodium sulfate, 1.2 kg of a 10 wt% aqueous solution of sodium bicarbonate, 1.3 kg of isooctyl thioglycolate, 30 kg of acrylonitrile, and 30 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 67 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 35° C., 55 kg of a 2 wt % potassium persulfate aqueous solution is added, and the polymerization reaction begins; when the polymerization reaction conversion rate reaches 42%, 5 kg of a 10 wt % polyoxyethylene alkyl ether sodium sulfate aqueous solution is added, and the temperature is raised to 45° C.; when the conversion rate reaches more than 88%, the temperature is further raised to 65° C.; when the conversion rate reaches more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 123 nm is obtained.

[0040] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 55:45 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0041] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxyl nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and the solid content of the emulsion was finally adjusted to 30%, and stirred for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 36MPa, a stress retention rate of 54%, and an elongation of 500%.

[0042] Example 8 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 90 kg of desalted water, 14 kg of a 10 wt% aqueous solution of sodium dodecylbenzenesulfonate, 2.4 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 1.9 kg of isooctyl mercaptopropionate, 15 kg of acrylonitrile, and 7.0 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 78.0 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 33° C., 40 kg of a 2 wt % sodium persulfate aqueous solution and 5 kg of a 2 wt % potassium persulfate aqueous solution are added, and the polymerization reaction begins; when the polymerization reaction conversion rate reaches 44%, 5 kg of a 10 wt % polyoxyethylene alkyl ether sodium sulfate aqueous solution is added, and the temperature is raised to 45° C.; when the conversion rate reaches more than 87%, the temperature is further raised to 60° C.; when the conversion rate reaches more than 93%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 125 nm is obtained.

[0043] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 80 kg of desalted water, 30 kg of 10 wt% sodium dodecylbenzene sulfonate aqueous solution, 1.6 kg of 10 wt% sodium bicarbonate aqueous solution, 0.9 kg of isooctyl mercaptopropionate, 32 kg of acrylonitrile, and 35 kg of 10 wt% itaconic acid aqueous solution are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 64.5 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 35° C., 60 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction begins; when the polymerization reaction conversion rate reaches 43%, 3 kg of a 10 wt % polyoxyethylene alkyl ether sodium sulfate aqueous solution is added, and the temperature is raised to 50° C.; when the conversion rate reaches more than 89%, the temperature is further raised to 58° C.; when the conversion rate reaches more than 93%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 86 nm is obtained.

[0044] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 50:50 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0045] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxylic nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and the solid content of the emulsion was finally adjusted to 30%, and stirred for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 34MPa, a stress retention rate of 51%, and an elongation of 570%.

[0046] Example 9 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 72 kg of desalted water, 28 kg of a 10 wt% aqueous solution of sodium dodecyl diphenyl oxide disulfonate, 0.8 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 0.7 kg of isooctyl thioglycolate, 18 kg of acrylonitrile, and 6.8 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 75.7 kg of 1,3-butadiene is added, and further emulsification is carried out for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 33° C., 80 kg of a 2 wt % sodium persulfate aqueous solution is added, and the polymerization reaction starts; when the polymerization reaction conversion rate reaches 43%, 9 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution is added, and the temperature is raised to 48° C.; when the conversion rate reaches more than 90%, the temperature is further raised to 55° C.; when the conversion rate reaches more than 95%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and a defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 101 nm is obtained.

[0047] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 75 kg of desalted water, 17 kg of a 10 wt% aqueous solution of sodium dodecyl diphenyl ether disulfonate, 1.7 kg of a 10 wt% aqueous solution of sodium bicarbonate, 0.6 kg of tert-dodecyl mercaptan, 29 kg of acrylonitrile, and 48 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 66.2 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature is raised to 42° C., 50 kg of 2 wt % ammonium persulfate aqueous solution and 25 kg of 2 wt % potassium persulfate aqueous solution are added, and the polymerization reaction begins; when the polymerization reaction conversion rate reaches 44%, 6 kg of 10 wt % polyoxyethylene alkyl ether sodium sulfate aqueous solution is added, and the temperature is raised to 48° C.; when the conversion rate reaches more than 84%, the temperature is further raised to 53° C.; when the conversion rate reaches more than 93%, 0.5 kg of 5 wt % sodium methylaminodithiocarboxylate aqueous solution is added to stop the reaction, and ammonia water and defoaming agent are added, and then the residual monomers are removed, the mixture is concentrated, and the pH is adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 125 nm is obtained.

[0048] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 45:55 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0049] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxyl nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and finally the emulsion solid content was adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, washing, and vulcanization, and the product had a tensile strength of 33MPa, a stress retention rate of 55%, and an elongation of 480%.

[0050] Example 10 Polymer microparticle dispersion A: After the pressure reactor is evacuated, 95 kg of desalted water, 26 kg of a 10 wt% aqueous solution of polyoxyethylene alkyl ether sodium sulfate, 0.9 kg of a 10 wt% aqueous solution of disodium ethylenediaminetetraacetate, 1.4 kg of tert-dodecyl mercaptan, 24 kg of acrylonitrile, and 5.4 kg of methacrylic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation for multiple times, 70.6 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature was raised to 39° C., 43 kg of a 2 wt % potassium persulfate aqueous solution was added, and the polymerization reaction started; when the polymerization reaction conversion rate reached 48%, 10 kg of a 10 wt % sodium dodecylbenzenesulfonate aqueous solution was added, and the temperature was raised to 45° C.; when the conversion rate reached more than 90%, the temperature was further raised to 62° C.; when the conversion rate reached more than 94%, 0.5 kg of a 5 wt % sodium methylaminodithiocarboxylate aqueous solution was added to stop the reaction, and ammonia water and a defoaming agent were added, and then the residual monomers were removed, the mixture was concentrated, and the pH was adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion A with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 100 nm was obtained.

[0051] Polymer microparticle dispersion B: After the pressure reactor is evacuated, 65 kg of desalted water, 23 kg of a 10 wt% aqueous solution of polyoxyethylene alkyl ether sodium sulfate, 2.8 kg of a 10 wt% aqueous solution of sodium bicarbonate, 0.4 kg of 2-ethylhexyl thioglycolate, 36.1 kg of acrylonitrile, and 29 kg of a 10 wt% aqueous solution of itaconic acid are added in sequence, stirring is started, and after nitrogen filling and evacuation operations are performed multiple times, 61 kg of 1,3-butadiene is added, and further emulsification is performed for 30 minutes to obtain a monomer emulsified dispersion. The temperature was raised to 41° C., 85 kg of a 2 wt % aqueous solution of ammonium persulfate was added, and the polymerization reaction started; when the polymerization reaction conversion rate reached 47%, 5 kg of a 10 wt % aqueous solution of sodium dodecylbenzenesulfonate was added, and the temperature was raised to 45° C.; when the conversion rate reached more than 86%, the temperature was further raised to 49° C.; when the conversion rate reached more than 95%, 0.5 kg of a 5 wt % aqueous solution of sodium methylaminodithiocarbamate was added to stop the reaction, and ammonia water and a defoaming agent were added, and then the residual monomers were removed, the mixture was concentrated, and the pH was adjusted with an alkaline aqueous solution, and finally a polymer microparticle dispersion B with a solid content of 43-45%, a pH of 8.3-8.5, and a particle size of 104 nm was obtained.

[0052] The polymer fine particle dispersion A and the polymer fine particle dispersion B are mixed at a solid content ratio of 63:37 to form a carboxylated nitrile latex for gloves having high tensile strength and high stress retention rate.

[0053] 1.0 parts by weight of sulfur, 0.5 parts by weight of vulcanization accelerator EZ, 1.5 parts by weight of zinc oxide, 1.5 parts by weight of titanium dioxide, 0.005 parts by weight of potassium hydroxide, a dispersant and water were added in sequence and mixed for ball milling dispersion to prepare a vulcanization dispersion. The dispersion was filtered through 300 meshes, and the vulcanization dispersion was slowly added to the carboxy nitrile emulsion while stirring. The pH was adjusted to 9.5-10 with 5% potassium hydroxide, and finally the solid content of the emulsion was adjusted to 30%, and stirring was maintained for 24 hours. Then, a dip-molded product was prepared in a calcium nitrate aqueous solution through processes such as dip molding, water washing, and vulcanization. The product had a tensile strength of 37MPa, a stress retention rate of 55%, and an elongation of 552%.

Claims

1. A carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate, characterized in that: The latex is composed of a polymer microparticle dispersion A and a polymer microparticle dispersion B in a certain proportion. Specifically, the polymer microparticle dispersion A is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and methacrylic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the polymer microparticle dispersion B is prepared by an emulsion copolymerization method of 1,3-butadiene, acrylonitrile and itaconic acid monomers in the presence of an emulsifier, a chain transfer agent, an electrolyte and a water-soluble oxidant, and is finally prepared after defoaming, removing residual monomers, concentrating and adjusting pH; the weight ratio of acrylonitrile in the polymer microparticles of the dispersion B is greater than the weight ratio of acrylonitrile in the polymer microparticles of the dispersion A, and the polymer microparticle dispersion A and the polymer microparticle dispersion B are combined in the range of 95:5 to 40:60 of the solid content to form a strength ≥30 MPa, stress retention rate ≥45% for gloves with carboxylated nitrile latex.

2. The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate according to claim 1, characterized in that: The polymer microparticle dispersion A contains a copolymer in which the content of 1,3-butadiene monomer units is 70.5w%~79.5w% (weight %), the content of acrylonitrile monomer units is 25w%~13w%, and the content of methacrylic acid monomer units is 4.5w%~7.5w%; the polymer microparticle dispersion B contains a copolymer in which the content of 1,3-butadiene monomer units is 59w%~69.5w% (weight %), the content of acrylonitrile monomer units is 40w%~25.5w%, and the content of itaconic acid monomer units is 1.0w%~5.0w% polymer microparticle dispersion B.

3. The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate according to claim 1, characterized in that: The polymer microparticle dispersion A has a particle size of 85-130 nm and a pH of 7.5-9.

0. The polymer microparticle dispersion B has a particle size of 80-130 nm and a pH of 7.5-9.

0.

4. The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate according to claim 1, characterized in that The water-soluble oxidant is a mixture of one or more of sodium persulfate, potassium persulfate, ammonium persulfate and hydrogen peroxide in any proportion; the usage amount of the water-soluble oxidant is 0.1-3.0 wt% of the total amount of monomers.

5. The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate according to claim 1, characterized in that The chain transfer agent is a mixture of one or more of dodecyl mercaptan, tert-dodecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, and isooctyl mercaptopropionate in any proportion; the amount of the chain transfer agent used is 0.3 to 2.0 wt% of the total monomer amount.

6. The carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate according to claim 1, characterized in that The electrolyte is a mixture of one or more of disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, sodium bicarbonate, and sodium pyrophosphate in any proportion; the amount of the electrolyte used is 0.02-0.3wt% of the total monomer amount; the emulsifier is a mixture of one or more of sodium dodecylbenzene sulfonate, sodium dodecyl diphenyl ether disulfonate, and sodium polyoxyethylene alkyl ether sulfate in any proportion; the amount of the emulsifier used is 1.2-4.2wt% of the total monomer amount.

7. Use of the carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate as claimed in any one of claims 1 to 6 for producing dip-molded glove products.

8. A method for preparing carboxylated nitrile latex for gloves with high tensile strength and high stress retention rate, characterized in that: The polymer microparticle dispersion A and the polymer microparticle dispersion B are mixed in a certain ratio, specifically, the polymer microparticle dispersion A and the polymer microparticle dispersion B are mixed in a solid content range of 95:5 to 40:60 to form a carboxylated nitrile latex for gloves with high tensile strength.