Butyronitrile latex composition, rubber glove and preparation method and application thereof

Abstract

The invention discloses a butyronitrile latex composition, a rubber glove and a preparation method and application of the rubber glove. The butyronitrile latex composition comprises the following components in parts by weight: 100 parts of carboxylic butyronitrile latex, 0.8-5 parts of an accelerant, 1-3 parts of a vulcanization activator, 0.8-4 parts of a vulcanizing agent, 0-2.5 parts of a stabilizer and 0-1.2 parts of an emulsifier, in the carboxylic butadiene-acrylonitrile latex, the mass content of carboxyl is 5-8%; the accelerant is one or more of dialkyl dithiocar-bamate and alkyl aryl dithiocar-bamate; the accelerant is one or more of dialkyl dithiocar-bamate and alkyl aryl dithiocar-bamate; the D50 particle size of the accelerant is 0.1 to 0.5 [mu] m, and the D90 particle size of the accelerant is 0.5 to 2.0 [mu] m. According to the butyronitrile latex composition provided by the invention, the vulcanization speed of reaction can be increased under the condition that the vulcanization temperature is not increased, the vulcanization time of a production line is greatly shortened, and the vulcanization time is shortened; and the mechanical property of a product prepared from the butyronitrile latex is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer compounds, and more specifically, relates to a nitrile latex composition, a rubber glove, and a preparation method and application thereof. Background Art

[0002] Nitrile rubber is made from butadiene and acrylonitrile by emulsion polymerization. Its products have excellent oil resistance, high wear resistance and good heat resistance. Nitrile gloves are insoluble in non-polar solvents and can effectively withstand non-polar reagents such as alkanes and cycloalkanes, such as n-pentane, n-hexane, cyclohexane and other solvents. Therefore, they are widely used in electronics, chemicals, aquaculture, glass, food and other factory protection, hospitals, scientific research and other industries.

[0003] Patent publication number CN114672082A discloses a carboxylated nitrile emulsion, which is first pre-cured twice at a vulcanization temperature of 80-130°C for 1-3 minutes, and then vulcanized in an oven at 110-140°C for 15-20 minutes. Patent publication number CN116535750A discloses a rubber glove and its preparation method and application. In the preparation process of the rubber glove, the vulcanization is performed at a temperature of 90-120°C for 20 to 40 minutes.

[0004] In the production process, vulcanization time is one of the important factors affecting production efficiency. By shortening the vulcanization time, the production rhythm can be accelerated, the output per unit time can be increased, and the overall production efficiency can be improved. However, excessively shortening the vulcanization time of nitrile rubber has a great impact on the performance of nitrile rubber. Insufficient vulcanization time may cause the rubber to be under-vulcanized, that is, the rubber does not have enough time to undergo sufficient chemical reaction and cross-linking, which will affect the mechanical properties of the rubber, such as tensile strength, elasticity, elongation at break, etc., which may not meet the expected requirements. Insufficient vulcanization may also affect the heat resistance and aging resistance of the rubber, which is especially important for nitrile rubber gloves that need to be used at higher temperatures or in harsh environments.

[0005] In the existing scheme, the problem of insufficient vulcanization of rubber can be compensated by increasing the vulcanization temperature to shorten the vulcanization time, so as to ensure that the rubber can be fully vulcanized. However, the increase in vulcanization temperature may also cause the rubber molecular chain to crack and vulcanize back to its original state, which will reduce the mechanical properties of the rubber and affect the strength and durability of the gloves; in addition, increasing the vulcanization temperature may also shorten the scorch time of the rubber and reduce the mold filling time, which may cause partial lack of rubber in the product and affect the uniformity and integrity of the gloves. Therefore, how to shorten the vulcanization time and ensure the mechanical properties of nitrile rubber without increasing the vulcanization temperature has become an important problem that needs to be solved urgently. Summary of the invention

[0006] In view of the above existing technical problems, the primary purpose of the present invention is to provide a nitrile latex composition. Based on the nitrile latex composition, the vulcanization speed of the reaction can be increased without increasing the vulcanization temperature (100-120°C), which greatly shortens the vulcanization time of the production line, improves production efficiency, reduces product costs, and ensures the mechanical properties of the nitrile latex.

[0007] The second object of the present invention is to provide a method for preparing a nitrile latex composition.

[0008] The third object of the present invention is to provide an application of a nitrile latex composition in the preparation of rubber gloves.

[0009] A fourth object of the present invention is to provide a rubber glove.

[0010] A fifth object of the present invention is to provide a method for preparing rubber gloves.

[0011] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0012] A nitrile latex composition, comprising the following components by weight: 100 parts of carboxyl nitrile latex, 0.8-5 parts of accelerator, 1-3 parts of vulcanization activator, 0.8-4 parts of vulcanizing agent, 0-2.5 parts of stabilizer, and 0-1.2 parts of emulsifier;

[0013] In the carboxylated nitrile latex, the mass content of carboxyl groups is 5-8%;

[0014] The accelerator is one or more of dialkyl dithiocarbamate and alkyl aryl dithiocarbamate; the D50 particle size of the accelerator is 0.1-0.5 μm, and the D90 particle size is 0.5-2.0 μm.

[0015] The present invention adopts carboxyl nitrile latex with a specific carboxyl content, which can provide more ionic bond cross-linking sites, thereby achieving rapid cross-linking. The inventors found that when the carboxyl content is low, the vulcanization time of the nitrile latex is greatly extended; while when the carboxyl content is high, the elongation at break of the prepared rubber gloves is low, and the mechanical properties of the rubber gloves are difficult to meet the requirements.

[0016] Furthermore, the inventors have found through research that accelerators of specific types and specific particle size ranges can significantly increase the vulcanization rate. Compared with the use of dithiocarbamates containing diaryl groups, the use of dialkyl dithiocarbamates and alkyl aryl dithiocarbamates as accelerators has less steric hindrance, which can be more conducive to the vulcanization reaction, thereby shortening the vulcanization time. As for the particle size of dithiocarbamates, when the D50 particle size and D90 particle size of the dithiocarbamates are too large, the contact efficiency with the vulcanizing agent particles becomes low, thereby affecting the vulcanization reaction and slowing down the vulcanization rate.

[0017] The present invention adopts carboxyl nitrile latex with a specific carboxyl content, dithiocarbamate of a specific type and a specific particle size range, and other components in the system, so that the vulcanization speed of the reaction can be increased without increasing the vulcanization temperature (100-120° C.), thereby greatly shortening the vulcanization time of the production line, improving production efficiency, and reducing product costs; and the mechanical properties of the prepared rubber gloves still meet the requirements.

[0018] Specifically, the number of accelerators can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, etc., or the range formed by any of the above values, such as 1-1.5 parts, 2-4 parts, etc., the present invention is not limited thereto. The number of vulcanization activators can be 1 part, 1.5 parts, 2 parts, 2.5 parts, etc., or the range formed by any of the above values, such as 1-1.5 parts, 2-2.5 parts, etc., the present invention is not limited thereto. The number of vulcanizing agents can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, etc., or the range formed by any of the above values, such as 1-1.5 parts, 2-3.5 parts, etc., the present invention is not limited thereto.

[0019] Specifically, in the carboxylated nitrile latex, the mass content of carboxyl can be 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, etc., or an interval range formed by any of the above values, such as 5.5-7%, 6.5-8%, etc., but the present invention is not limited thereto. More specifically, the test method for the mass content of carboxyl in the carboxylated nitrile latex is: acid-base titration method.

[0020] Specifically, the carboxylated nitrile latex can be obtained by copolymerizing butadiene, acrylonitrile and methacrylic acid. Specifically, by weight, the amount of butadiene is 50-85 parts, and the amount of acrylonitrile is 25-30 parts; more specifically, the amount of butadiene is 53-68 parts, and the amount of acrylonitrile is 25-29 parts.

[0021] Specifically, the mass percentage of acrylonitrile in the carboxylated nitrile latex is 15-30%. Specifically, the weight percentage of the carboxylated nitrile latex is the weight percentage of the dry rubber.

[0022] Specifically, the D50 particle size of the accelerator can be 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, etc., or an interval range formed by any of the above values, such as 0.15-0.35 μm, 0.15-0.4 μm, 0.25-0.45 μm, etc., and the present invention is not limited thereto. More specifically, the test method for the D50 particle size of the accelerator is: GB / T 29022-2021 particle size analysis, dynamic light scattering (DLS).

[0023] Specifically, the D90 particle size of the accelerator can be 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, etc., or an interval range formed by any of the above values, such as 0.6-1 μm, 0.8-1.6 μm, 1.2-1.8 μm, etc., and the present invention is not limited thereto. More specifically, the test method for the D90 particle size of the accelerator is: GB / T29022-2021 particle size analysis, dynamic light scattering (DLS).

[0024] Specifically, the D50 particle size of the accelerator is 0.15-0.5 μm, and the D90 particle size is 0.5-1.7 μm.

[0025] Preferably, the D50 particle size of the accelerator is 0.15-0.3 μm, and the D90 particle size is 0.6-0.9 μm. Under this preferred particle size, the speed of the vulcanization reaction can be better increased, the time of the vulcanization reaction can be shortened, and the rubber gloves prepared have better tensile strength at break.

[0026] Specifically, the D50 particle size refers to the particle size value corresponding to the cumulative distribution percentage from small to large in the particle size distribution reaching 50%, also known as the median particle size. The D90 particle size refers to the particle size value corresponding to the cumulative distribution percentage from small to large in the particle size distribution reaching 90%.

[0027] Specifically, the accelerator of the specific D50 particle size and D90 particle size in the present invention can be obtained by directly purchasing or grinding after purchase. In some specific embodiments, the accelerator of the specific particle size can be obtained under the conditions of grinding speed of 1000-1500rpm and grinding time of 30-60min. In some specific embodiments, the accelerator of the specific particle size can be obtained by grinding after mixing the accelerator and the vulcanizing agent. More specifically, the grinding speed can be 1000-1500rpm, and the grinding time can be 15-30min.

[0028] Preferably, the accelerator is selected from one or more of zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate or zinc diisobutyldithiocarbamate.

[0029] Further preferably, the accelerator is selected from one or more of zinc dimethyl dithiocarbamate, zinc diethyl dithiocarbamate, and zinc di-n-butyl dithiocarbamate. Compared with other accelerators, the use of zinc dialkyl dithiocarbamate as an accelerator can better shorten the vulcanization time, and the prepared rubber gloves have better mechanical properties.

[0030] Preferably, the emulsifier is selected from one or more of alkyl sulfonates and alkyl sulfates. Further preferably, the emulsifier is selected from one or more of sodium dodecylbenzene sulfonate, ammonium dodecyl sulfate, sodium dodecyl sulfate, and sodium secondary alkyl sulfonate.

[0031] Preferably, the vulcanization activator is selected from one or more of zinc oxide and zinc stearate. More specifically, the D50 particle size of the vulcanization activator is 0.5-1.0um; the D90 particle size is 1-3um. The detection method of the D50 particle size and the D90 particle size of the vulcanization activator is: GB / T 29022-2021 particle size analysis, dynamic light scattering (DLS).

[0032] Preferably, the vulcanizing agent is selected from a sulfur donor. More specifically, the sulfur donor can be at least one of ordinary sulfur, insoluble sulfur or pre-dispersed sulfur. More specifically, the D50 particle size of the sulfur donor is 0.5-1.0um; the D90 particle size is 1-5um. The detection method of the D50 particle size and the D90 particle size of the sulfur donor is: GB / T 29022-2021 particle size analysis, dynamic light scattering (DLS).

[0033] Preferably, the stabilizer is selected from one or both of sodium hydroxide and potassium hydroxide.

[0034] Furthermore, the present invention seeks to protect a method for preparing a nitrile latex composition, comprising the steps of: uniformly mixing carboxyl nitrile latex, a vulcanizing agent, a vulcanization activator and an accelerator, as well as other components in the system to obtain the nitrile latex composition.

[0035] Preferably, the solid content of the nitrile latex composition is in the range of 14-24%. Further preferably, the solid content is in the range of 14-20%. The solid content test method is as follows: weigh 2.0±0.5g of the nitrile latex composition, dry it in an oven at 105°C for 2h until the nitrile latex sample has a constant weight, weigh the dry rubber mass, and the dry rubber mass / initial latex mass×100% is the solid content.

[0036] More specifically, in some embodiments, the vulcanizing agent may be prepared as a dispersion containing the vulcanizing agent, and / or the vulcanization activator may be prepared as a dispersion containing the vulcanization activator and mixed with other components in the system.

[0037] Furthermore, the present invention seeks to protect the use of the nitrile latex composition in the preparation of rubber gloves.

[0038] Furthermore, the present invention seeks to protect a rubber glove prepared using the above-mentioned nitrile latex composition.

[0039] Furthermore, the present invention claims protection for a method for preparing rubber gloves: immersing a mold in a demoulding liquid and drying; immersing the dried mold in the above-mentioned nitrile latex composition and drying; then immersing the dried mold again in the above-mentioned nitrile latex composition and drying; washing, heat vulcanizing, and demoulding to obtain the rubber gloves.

[0040] Preferably, the demoulding liquid can be a demoulding liquid conventionally used in the art for preparing rubber gloves. More specifically, in some specific embodiments, the demoulding liquid comprises, by weight: 10-30 parts of a coagulant, 1-3 parts of a release agent, and 67-89 parts of deionized water.

[0041] Preferably, the coagulant can be a coagulant conventionally used in the art for preparing rubber gloves. More specifically, in some embodiments, the coagulant is selected from one or more of calcium nitrate, magnesium nitrate, and calcium chloride.

[0042] Preferably, the release agent can be a release agent conventionally used in the art for preparing rubber gloves. More specifically, in some specific embodiments, the release agent can be a stearate, such as calcium stearate, sodium stearate, zinc stearate, etc.

[0043] Preferably, the temperature of the mold being immersed in the demoulding liquid is 50-70°C, and the temperature of the subsequent drying is 60-100°C.

[0044] Preferably, the temperature of dipping the mold into the nitrile latex composition is 25-35°C, and the temperature of subsequent drying is 60-100°C.

[0045] Preferably, the temperature of the thermal vulcanization is 100-120° C. and the time is 6-15 min.

[0046] Preferably, the mold is pre-treated before being immersed in the demoulding liquid, and the pre-treatment steps include: washing the mold with acid, alkali and water, and then drying it to make the mold surface free of stains and oil.

[0047] Specifically, the acid for pickling can be an organic acid or an inorganic acid commonly used in the art, such as nitric acid, etc.; the concentration of the acid can be 1-6%. The alkali for alkali washing can be an alkali commonly used in the art, such as sodium hydroxide, potassium hydroxide, etc.; the concentration of the alkali can be 3-8%. Preferably, the temperature of the water washing is 40-70°C, and the conductivity of the mold surface after the water washing does not exceed 5000uS / cm.

[0048] Furthermore, the present invention seeks to protect the use of the above-mentioned rubber gloves in the medical or pharmaceutical fields, cleaning fields, electronic and electrical fields, and food fields, including but not limited to medical surgery, medical examinations, scientific research laboratories, daily cleaning (such as kitchens, toilets, homes, etc.), food processing, etc.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention provides a nitrile latex composition, which can increase the vulcanization speed of a reaction without increasing the vulcanization temperature, greatly shortens the vulcanization time of a production line, improves production efficiency, and reduces product costs; and the mechanical properties of the rubber gloves prepared still meet the requirements. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with the specification and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0052] The raw materials of the embodiments and comparative examples are as follows:

[0053] Accelerator 1, zinc dimethyldithiocarbamate, D50 particle size is 0.3 μm, D90 particle size is 0.9 μm; Accelerator 1 is obtained by the following preparation method: zinc dimethyldithiocarbamate (trade name PZ, Guangzhou Li Xin Trading Co., Ltd.) is treated as follows: zinc dimethyldithiocarbamate and water are mixed and ground at a grinding speed of 1300 rpm and a grinding time of 40 min.

[0054] Accelerator 2, zinc ethylphenyl dithiocarbamate, D50 particle size is 0.45 μm, D90 particle size is 1.4 μm. The preparation method of accelerator 1 is referred to, except that the grinding speed is 1500 rpm and the grinding time is 45 min.

[0055] Accelerator 3, zinc dibenzyl dithiocarbamate, D50 particle size of 0.5 μm, D90 particle size of 1.7 μm. The preparation method of accelerator 1 is referred to, except that the grinding speed is 1500 rpm and the grinding time is 45 min.

[0056] Accelerator 4, zinc dimethyldithiocarbamate, D50 particle size is 0.15 μm, D90 particle size is 0.6 μm. The preparation method of accelerator 1 is referred to, except that the grinding speed is 1500 rpm and the grinding time is 60 min.

[0057] Accelerator 5, zinc dimethyldithiocarbamate, D50 particle size is 0.5 μm, D90 particle size is 1.4 μm. The preparation method of accelerator 1 is referred to, except that the grinding speed is 1000 rpm and the grinding time is 30 min.

[0058] Accelerator 6, zinc dimethyldithiocarbamate, D50 particle size is 0.6um, D90 particle size is 2.5um. The preparation method of accelerator 1 is referred to, except that the grinding speed is 1000rpm and the grinding time is 20min.

[0059] Carboxylated nitrile latex 1, the mass content of carboxyl is 5%. The preparation method of carboxylated nitrile latex refers to the following steps: in a reaction kettle, deionized water, emulsifier (sodium dodecylbenzene sulfonate), monomers (butadiene, acrylonitrile and methacrylic acid), and molecular weight regulator (dodecyl mercaptan) are added in sequence. After multiple nitrogen replacements, an initiator (potassium persulfate) is added to complete the polymerization reaction. The polymerization temperature is 30-60°C and the polymerization time is 10-12h. By adjusting the feed ratio of methacrylic acid and controlling the ratio of acrylonitrile / total monomer to remain unchanged, a carboxylated nitrile latex with a specific carboxyl content is obtained. By weight, 9.56 parts of methacrylic acid, 28 parts of acrylonitrile, and 62.44 parts of butadiene.

[0060] Carboxylated nitrile latex 2 has a carboxyl content of 8% by mass and differs from carboxylated nitrile latex 1 in that it contains 15.29 parts of methacrylic acid, 27 parts of acrylonitrile and 57.71 parts of butadiene.

[0061] Carboxylated nitrile latex 3 has a carboxyl content of 2% by mass, and differs from carboxylated nitrile latex 1 in that it contains 3.82 parts of methacrylic acid, 29 parts of acrylonitrile, and 67.18 parts of butadiene.

[0062] Carboxylated nitrile latex 4 has a carboxyl content of 11%, and differs from carboxylated nitrile latex 1 in that it contains 21.02 parts of methacrylic acid, 25 parts of acrylonitrile, and 53.98 parts of butadiene.

[0063] Vulcanization activator, zinc oxide, Guangzhou Li Xin Trading Co., Ltd.

[0064] Vulcanizing agent, sulfur, Guangzhou Li Xin Trading Co., Ltd.

[0065] Emulsifier, sodium dodecylbenzene sulfonate, commercially available.

[0066] Stabilizer, sodium hydroxide, commercially available.

[0067] Coagulant, calcium nitrate, commercially available.

[0068] Release agent, calcium stearate, commercially available.

[0069] Unless otherwise specified, the components (such as coagulant, release agent) selected in each parallel embodiment and comparative example are the same commercially available products.

[0070] Example 1

[0071] The weight parts of the raw materials used in Example 1 are shown in Table 1.

[0072] A nitrile latex composition, comprising the following specific steps:

[0073] (1) Sulfurizing agent dispersion: The sulfiding agent and water are mixed, and the mixture is ground and dispersed to obtain a sulfiding agent dispersion (wherein the D50 particle size of the sulfiding agent is 1.0 μm, and the D90 particle size is 3.5 μm).

[0074] Vulcanization activator dispersion: The vulcanization activator and water are mixed, and the vulcanization activator dispersion is obtained after grinding and dispersion (wherein the D50 particle size of the vulcanization activator is 0.7 um, and the D90 particle size is 1.8 um).

[0075] The vulcanizing agent dispersion, the vulcanization activator dispersion and the accelerator are mixed to obtain a vulcanization package dispersion.

[0076] (2) The vulcanization package dispersion and other components in the system are mixed, stirred for 20 hours, and then deionized water is added to mix evenly to obtain a nitrile latex composition (the solid content of the nitrile latex composition is 16%).

[0077] Example 2-Example 7

[0078] The weight parts of the raw materials used in the following examples are shown in Table 1.

[0079] The specific preparation steps of the following examples are the same as those of Example 1.

[0080] Comparative Example 1-Comparative Example 4

[0081] The weight parts of the raw materials used in the following comparative examples are shown in Table 2.

[0082] The specific preparation steps of other comparative examples are the same as those of Example 1.

[0083] Table 1

[0084]

[0085] Table 2

[0086]

[0087]

[0088] Example 8

[0089] Example 8 The nitrile latex composition prepared in Example 1 was used to prepare rubber gloves, and the preparation method was as follows:

[0090] (1) Clean the mold with acid and alkali and dry it to ensure that there is no stain or oil on the surface of the mold;

[0091] (2) The mold is immersed in a demoulding liquid at 60° C., taken out, and then rotary dried at 80° C. The demoulding liquid comprises, by weight, 20 parts of calcium nitrate, 2 parts of calcium stearate, and 78 parts of deionized water.

[0092] (3) At 30°C, the mold after the release liquid is dried is immersed in the nitrile latex composition prepared in Example 1, taken out, and rotary dried at 80°C; at 30°C, the mold is immersed in the nitrile latex again, taken out for the second time, and rotary dried at 80°C.

[0093] (4) The mold after drying is filtered with clean water, hot-vulcanized at 100° C., and demoulded to prepare rubber gloves.

[0094] Example 9-Example 14

[0095] The difference between Example 9 to Example 14 and Example 8 is that the rubber gloves are prepared using the nitrile latex compositions prepared in Examples 2-7, respectively.

[0096] Comparative Example 5-Comparative Example 8

[0097] The difference between Comparative Examples 5 to 8 and Example 8 is that the rubber gloves are prepared using the nitrile latex compositions prepared in Comparative Examples 1-4, respectively.

[0098] Test Case

[0099] The rubber gloves prepared in the above examples and comparative examples were tested using the following method:

[0100] (1) Tensile strength at break: The heat vulcanization time in step (4) was 10 minutes. The test was performed according to the ASTM D5034-2017 standard method. The samples were uniformly cut into dumbbells with a length of 115 mm and a width of 6 mm. The standard test temperature was 23±2° C., and the relative humidity was maintained at 50±5%. The test was performed on a motor-driven machine at a uniform speed of 500±50 mm / min, and the distance was at least 750 mm.

[0101] (2) Elongation at break: The heat vulcanization time in step (4) is 10 minutes, and the test is performed according to the ASTM D5034-2017 standard method. 13 samples are cut using a standard cutter, and the results are averaged.

[0102] (3) Thickness: The thickness was measured at room temperature using a Mitutoyo 547-401 thickness tester.

[0103] (4) Standard requirements: tensile strength at break ≥ 18 MPa, elongation at break ≥ 500%.

[0104] (5) Vulcanization speed: Tested in accordance with the GB / T 25268-2010 Rubber Vulcanizer User Guide. T70 is the vulcanization time (min) for nitrile rubber products to achieve product performance in actual production, T70 = [ML + (MH-ML) × 70%]. Among them, ML is the minimum torque and MH is the maximum torque.

[0105] The test results are shown in Tables 3 and 4 below.

[0106] Table 3

[0107] Test items Example 8 Example 9 Example 10 Embodiment 11 Example 12 Example 13 Embodiment 14 Sample thickness mm 0.059 0.06 0.062 0.061 0.061 0.06 0.061 Tensile strength at break MPa 43 42.7 22.7 45.5 35.1 41.5 38.1 Elongation at break % 572 584 649 553 612 591 595 Test items Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Sample thickness mm 0.059 0.061 0.065 0.061 Tensile strength at break MPa 19.4 46.1 25.5 20.5 Elongation at break % 671 450 633 661

[0108] Table 4

[0109] Test items Example 8 Example 9 Example 10 Embodiment 11 Example 12 Example 13 Embodiment 14 T70 7：02 7：11 10：45 6：06 9：35 11：17 11：02 Test items Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 T70 15：25 12:35 17：37 13：30

[0110] It can be seen from Tables 3 and 4 above that by using carboxylated nitrile latex with a specific carboxyl content, dithiocarbamate of a specific type and a specific particle size range, and matching other components in the system, rapid vulcanization can be achieved without increasing the vulcanization temperature, and the mechanical properties of the prepared rubber gloves meet the requirements. More specifically, the vulcanization time T70 is within 12 minutes, and the prepared rubber gloves have a tensile strength of ≥18MPa and an elongation at break of ≥500%.

[0111] It can be seen from Examples 8 and 10 that, compared with zinc ethylphenyl dithiocarbamate, the use of zinc dimethyl dithiocarbamate as an accelerator can better shorten the vulcanization time, and the rubber gloves prepared have better mechanical properties.

[0112] It can be seen from Examples 8, 11 and 12 that under this preferred particle size, the vulcanization time can be better shortened, and the rubber gloves prepared have better tensile strength at break.

[0113] It can be seen from Example 8, Example 14, Comparative Example 5 and Comparative Example 6 that the carboxyl nitrile latex with a specific mass content of carboxyl can better improve the vulcanization speed and shorten the vulcanization time. When the mass content of the carboxyl group is high, the mechanical properties of the prepared rubber gloves are poor and do not meet the standard requirements.

[0114] It can be seen from Example 8, Comparative Example 7 and Comparative Example 8 that when zinc dibenzyldithiocarbamate is used as the accelerator, or when the accelerator particle size is large, it is difficult to achieve the technical effect of the present invention.

[0115] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to require the widest possible range that can be imagined, and the embodiments presented herein are demonstrated by the applicant's actual test results. Therefore, the applicant's intention is that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges therein, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A nitrile latex composition, characterized in that The composition comprises the following components by weight: 100 parts of carboxyl nitrile latex, 0.8-5 parts of accelerator, 1-3 parts of vulcanization activator, 0.8-4 parts of vulcanizing agent, 0-2.5 parts of stabilizer and 0-1.2 parts of emulsifier; In the carboxylated nitrile latex, the mass content of carboxyl groups is 5-8%; The accelerator is one or more of dialkyl dithiocarbamate and alkyl aryl dithiocarbamate; the D50 particle size of the accelerator is 0.1-0.5 μm, and the D90 particle size is 0.5-2.0 μm.

2. The nitrile latex composition according to claim 1, characterized in that The accelerator is selected from one or more of zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate or zinc diisobutyldithiocarbamate.

3. The nitrile latex composition according to claim 1, characterized in that The D50 particle size of the accelerator is 0.15-0.5 μm, and the D90 particle size is 0.5-1.7 μm.

4. The nitrile latex composition according to claim 1, characterized in that The emulsifier is selected from one or more of alkyl sulfonates and alkyl sulfates.

5. The nitrile latex composition according to claim 1, characterized in that: The vulcanization activator is selected from one or more of zinc oxide and zinc stearate; and / or The vulcanizing agent is selected from sulfur donors.

6. The nitrile latex composition according to claim 1, characterized in that: The stabilizer is selected from one or both of sodium hydroxide and potassium hydroxide.

7. The method for preparing the nitrile latex composition according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: uniformly mixing carboxyl nitrile latex, a vulcanizing agent, a vulcanization activator and an accelerator as well as other components in the system to obtain a nitrile latex composition.

8. Use of the nitrile latex composition according to any one of claims 1 to 6 in the preparation of rubber gloves.

9. A rubber glove, characterized in that: The nitrile latex composition is prepared by using any one of claims 1 to 6.

10. A method for preparing rubber gloves, characterized in that: The mold is immersed in a demoulding liquid and dried; the dried mold is immersed in the nitrile latex composition according to any one of claims 1 to 6 and dried; then the dried mold is immersed in the nitrile latex composition again and dried; cleaning, heat vulcanization, and demoulding to obtain a rubber glove.

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