CN116041808A - A kind of nitrile latex composition, nitrile gloves and preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of nitrile gloves, and discloses a nitrile latex composition, a nitrile glove, a preparation method and application. The nitrile latex composition disclosed by the invention comprises the following components in parts by weight: 100 parts of nitrile rubber latex, 1-3 parts of triazine-formaldehyde condensate resin and 0.3-0.7 part of vulcanizing agent. The nitrile glove prepared from the nitrile latex composition has high elongation and low stretching stress, and the performance of the nitrile glove reaches or even exceeds the performance and hand feeling of the natural latex glove; after the glove is aged, the elongation and the stretching stress are not greatly changed; and is very durable; is suitable for the field of medical gloves.

Description

A nitrile latex composition, nitrile gloves, and preparation method and application thereof

Technical Field

The present invention relates to the technical field of nitrile gloves, and in particular to a nitrile latex composition, nitrile gloves, and a preparation method and application thereof.

Background Art

Disposable rubber gloves are widely used in medical examination, health protection, food industry and other fields. They are easy to use and can be discarded after use. Gloves used for medical purposes can be subdivided into latex gloves with natural rubber latex as the main raw material, nitrile gloves with nitrile rubber latex as the main raw material, and PVC gloves with polyvinyl chloride paste resin and plasticizer as the main raw materials, etc. According to different materials, natural latex gloves have a soft feel and high elongation, but are not resistant to oil and organic solvents, contain proteins that can cause human allergies, and are expensive and have a limited range of applications; PVC gloves are cheap, but have a hard feel and low elongation, and the plasticizers in them are easily dissolved when encountering organic solvent components, and the protective performance is very poor; nitrile gloves are reasonably priced, and their oil and solvent resistance far exceeds that of latex gloves and PVC gloves. They are widely used, but nitrile gloves have low elongation and are not durable. The physical property requirements of the ASTM standard for medical examination gloves of these three materials are shown in Table 1, where the aging is after accelerated aging at 70°C for 168 hours as specified in the standard.

Table 1 Standard ASTM D412

Physical performance requirements of gloves Natural latex gloves Nitrile gloves PVC gloves Strength before aging (MPa) 18 14 7.5 Elongation before aging (%) 650 500 300 Strength after aging (MPa) 14 14 7.5 Elongation after aging (%) 500 400 300 Product Requirements-American Standard Number ASTM D3578 ASTM D6319 ASTM D5250

The tensile stress of natural latex gloves is also lower than that of conventional nitrile gloves and PVC gloves, and they feel softer. For example, the 300% tensile stress of natural latex gloves is generally only 1Mpa to 4Mpa, but the 300% tensile stress of conventional nitrile gloves reaches 6Mpa to 15Mpa, and the 300% tensile stress of PVC gloves is generally more than 7Mpa. At the same time, the performance of natural latex gloves and nitrile gloves will decrease after aging, especially the elongation will decrease significantly, resulting in the performance of the gloves after long-distance transportation or storage, and the elongation and softness will decrease.

In addition, existing nitrile gloves are not durable, especially when the elongation of the gloves is high. For example, gloves with an elongation of 600% will be damaged if worn continuously for no more than 60 minutes. Many gloves will develop cracks and holes after being worn continuously and used normally for more than 90 minutes, especially in the base of the thumb, between the fingers and other places that are subjected to more force during daily use. Not only does it require users to change gloves frequently, which invisibly increases costs, but also because minor damage during use is not easy to detect, there is a potential risk of losing the protective effect.

Therefore, it is urgent to develop a nitrile latex composition that can make the gloves have both elongation, tensile stress and durability, so as to be applied to medical gloves.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a nitrile latex composition, a nitrile glove, a preparation method and an application, so as to overcome the problem in the prior art that it is difficult to coordinate the strength, softness and durability of medical nitrile gloves.

To achieve the above purpose, the technical solution adopted by the present invention is as follows:

In a first aspect, the present invention provides a nitrile latex composition, comprising the following components by weight: 100 parts of nitrile rubber latex, 1 to 3 parts of triazine-formaldehyde condensate resin and 0.3 to 0.7 parts of a vulcanizing agent;

The acrylonitrile content of the nitrile rubber latex is 28% to 35%, preferably 29% to 32% or 33% to 34%.

In the nitrile latex composition of the present invention, the vulcanizing agent opens and bridges the unsaturated double bonds in the uncrosslinked linear polymer chains in the nitrile rubber latex with a specific acrylonitrile content to form a network structure with high strength and elongation; the triazine-formaldehyde condensate resin in a specific proportion not only regulates the crosslinking degree of the nitrile rubber latex by the vulcanizing agent, but also crosslinks and fills the linear polymer of the nitrile rubber by itself, balances the strength, elongation and tensile stress of the crosslinked nitrile rubber latex, and improves the durability of the gloves. The prepared nitrile gloves are soft and comfortable to wear, and the hand feel is close to that of natural latex gloves; the tensile stress and elongation are close to those of natural latex gloves; the performance does not decrease significantly after aging, and the durability is good.

As a preferred embodiment of the nitrile latex composition of the present invention, the mass ratio of the triazine-formaldehyde condensate resin to the vulcanizing agent is 2 to 10:1.

As a preferred embodiment of the nitrile latex composition of the present invention, the vulcanizing agent is sulfur or tetramethylthiuram disulfide.

As a preferred embodiment of the nitrile latex composition of the present invention, it also includes at least one of an activator, a accelerator, an antioxidant, and a colorant.

Furthermore, based on weight, the composition further includes 0 to 0.4 parts of an active agent, 0 to 0.7 parts of an accelerator, 0 to 0.5 parts of an antioxidant and 0 to 0.8 parts of a pigment.

Furthermore, the active agent is a divalent metal oxide; preferably, the active agent is magnesium oxide or zinc oxide; the promoter is a zinc salt of thiocarbamate or thiazole; preferably, the promoter is at least one of promoter ZDEC, promoter ZDBC, and promoter ZMBT; the antioxidant is at least one of phenols, amines, phosphites, and hindered phenol antioxidants.

In a second aspect, the present invention provides a nitrile glove made from the nitrile latex composition.

The nitrile gloves of the present invention have high elongation and low tensile stress, and their performance reaches or exceeds the performance and feel of natural latex gloves; and the gloves are relatively durable; after aging, the elongation and tensile stress of the gloves do not change much, indicating that the gloves still maintain elasticity and softness even after long-term storage. Compared with conventional nitrile gloves, the elongation of the gloves is greatly improved, and the tensile stress is significantly reduced.

In a third aspect, the present invention provides a method for preparing nitrile gloves, comprising the following steps:

(1) taking the components of the nitrile latex composition and mixing them to obtain a premixed nitrile latex;

(2) Immerse the hand model in a coagulant; then take out the hand model and dry it;

(3) immersing the hand mold into the obtained premixed nitrile latex, then taking out the hand mold and drying it;

(4) leaching treatment, drying and vulcanization molding;

(5) After chlorination treatment, demoulding is completed.

As a preferred embodiment of the method for preparing nitrile gloves, in step (2), the coagulant is calcium nitrate or calcium chloride.

In a fourth aspect, the present invention applies the nitrile latex composition, the nitrile gloves, and the preparation method in medical gloves.

The nitrile gloves of the present invention are close to natural latex gloves, are softer, and are comfortable to wear; they are very durable and can be used continuously for at least more than 2 hours without being damaged; and they are suitable for medical gloves.

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

The nitrile gloves prepared from the nitrile latex composition of the present invention have high elongation and low tensile stress, and their performance reaches or exceeds the performance and feel of natural latex gloves, and they feel softer and more comfortable to wear; after aging, the elongation and tensile stress of the gloves do not change much, and the gloves still feel elastic and soft even after long-term storage. Compared with conventional nitrile gloves, the elongation of the gloves is greatly improved, and the tensile stress is significantly reduced; and they are very durable, and can be used continuously for at least more than 2 hours without being damaged; and they are suitable for the field of medical gloves.

DETAILED DESCRIPTION

To better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be understood by those skilled in the art that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

In the following examples and comparative examples, unless otherwise specified, the vulcanizing agent, activating agent, accelerator, antioxidant and pigment are all commercially available, and the same vulcanizing agent, activating agent, accelerator, antioxidant and pigment are used in parallel experiments.

The raw materials used in the following examples and comparative examples are described as follows, but are not limited to these materials:

Nitrile rubber latex 1: model NL105, acrylonitrile content 28%, purchased from Ningbo Yongxing Chemical Co., Ltd.;

Nitrile rubber latex 2: model JZAH-3, acrylonitrile content 35%, purchased from Dongying Jiuzhou Aohua Chemical Co., Ltd.;

Nitrile rubber latex 3: model Nantex 640E, acrylonitrile content of 37%, purchased from Zhenjiang Nandi Chemical Co., Ltd.;

Nitrile rubber latex 4: model Nantex 660, acrylonitrile content of 25%, purchased from Zhenjiang Nandi Chemical Co., Ltd.;

Nitrile rubber latex 5: model X6617, acrylonitrile content 32%, purchased from Shanghai Xintema Chemicals Co., Ltd.;

Triazine-formaldehyde condensate resin: model: BOC Sciences, purchased from BOCSCI Inc., USA;

Vulcanizing agent: sulfur, commercially available;

Active agent: magnesium oxide, commercially available;

Accelerator: Accelerator ZDEC, commercially available;

Antioxidant: Antioxidant 2246, commercially available;

Pigment: Titanium dioxide, commercially available.

The components of the nitrile latex compositions of Examples 1 to 10 and Comparative Examples 1 to 6 are shown in Table 2.

Table 2 Components of nitrile latex composition (parts by weight)

The nitrile latex compositions of Examples 1 to 10 and Comparative Examples 1 to 6 were used to prepare nitrile gloves, respectively, and the specific preparation steps were as follows:

(1) taking the components of the nitrile latex compositions of Examples 1 to 10 and Comparative Examples 1 to 6, mixing them to obtain a premixed nitrile latex;

(2) cleaning the handle mold and drying the moisture on the surface, and then immersing it in a coagulant, which is a calcium nitrate aqueous solution; taking out the handle mold, putting it in an oven, and drying the coagulant on the surface;

(3) immersing the handle mold into premixed nitrile latex, taking out the handle mold, and placing it in an oven for drying;

(4) Leaching treatment, high temperature drying and vulcanization molding at 90℃～130℃;

(5) After chlorination treatment, the gloves are demoulded to obtain nitrile gloves.

The relevant properties of the nitrile gloves prepared by the nitrile latex compositions of Examples 1 to 10 and Comparative Examples 1 to 6 were tested, and the specific testing method was as follows:

(1) The standard "ASTM-D412 Tensile Test Method for Vulcanized Rubber and Thermoplastic Elastomer" was used to test the relevant properties of the nitrile gloves prepared using the nitrile latex compositions of Examples 1 to 10 and Comparative Examples 1 to 6, wherein the aging refers to the accelerated aging at 70° C. for 168 hours as specified in the standard.

(2) The durability testing method is as follows:

Randomly select 10 workers in the same position from the company's production workshop, including 5 men and 5 women. Before wearing the gloves, first inflate the gloves to check to ensure that there are no visual holes in the gloves and some areas that are obviously thin; then arrange for each worker to wear gloves on both hands, and then carry out daily work. The 10 workers have the same work content; the inspectors visually inspect the gloves worn on the hands of the workers every 5 minutes to see if there are cracks, holes and other damage. If there is damage, stop wearing and record the time of wear; if the gloves are still not broken after two hours, the test is terminated. The inspectors record the wear-in time of all gloves, and the result is the median of the wear-in time of all gloves. The longer the wear-in time, the more durable the gloves.

The test results are shown in Table 3.

Table 3 Properties of nitrile gloves

Table 3: Properties of nitrile gloves

performance Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Strength before aging (MPa) 9.6 21.2 18.3 7.2 20.1 23.9 Elongation before aging (%) 695.5 598.8 700.8 780.6 746.8 700.8 300% tensile stress before aging (MPa) 3.1 4.2 2.7 2.1 2.5 3.0 Strength after aging (MPa) 17.4 28.5 25.4 13.6 23.5 30.2 Elongation after aging (%) 598.3 527.2 698.9 761.8 741.2 576.4 300% tensile stress after aging (MPa) 3.9 4.8 2.8 2.6 2.9 4.2 Durability (continuous wearing time) 20 minutes rupture 25 minutes rupture 25 minutes rupture More than 2 hours 90 Minutes Rupture More than 2 hours

The nitrile gloves prepared with the nitrile latex compositions of Examples 1 to 10 have high elongation and low tensile stress, and their performance reaches or exceeds the performance and feel of natural latex gloves, and they feel softer and more comfortable to wear; and the gloves are relatively durable; after aging, the elongation and tensile stress of the gloves do not change much, indicating that the gloves still maintain elasticity and softness even after long-term storage. Compared with conventional nitrile gloves, the elongation of the gloves is greatly improved, and the tensile stress is significantly reduced.

Compared with Example 1, the acrylonitrile contents of the acrylonitrile latex in the nitrile gloves of Comparative Examples 1 and 2 are 37% and 25% respectively, and the performance of the two products is polarized: the strength of the nitrile latex with a content of 37% is unqualified, but the elongation is relatively high, while the strength of the nitrile latex with a content of 25% is qualified, but the elongation is relatively low, and the durability of the two gloves is relatively poor; the nitrile latex composition used in the nitrile gloves of Comparative Example 3 does not add triazine-formaldehyde condensate resin, although the performance before and after aging is acceptable, and the gloves are relatively soft, but due to the loss of the auxiliary cross-linking filling effect of the resin, the elongation of the gloves is slightly low, and the gloves are very not durable, and the continuous use time is short; the nitrile latex composition used in the nitrile gloves of Comparative Example 4 does not add a vulcanizing agent, although it has a relatively high elongation , lower tensile stress, and good durability, but the tensile strength is obviously low, less than 14Mpa, which does not meet the standard requirements; in the nitrile latex composition used in the nitrile gloves of Comparative Example 5, the mass ratio of triazine-formaldehyde condensate resin to vulcanizing agent is 1:1. Due to the low usage of the resin, the other properties of the gloves are OK, but although the durability is worse than that of the comparative example without any resin, it is obviously not as good as the comparative example with normal usage; in the nitrile latex composition used in the nitrile gloves of Comparative Example 6, the mass ratio of triazine-formaldehyde condensate resin to vulcanizing agent is 12.5:1. Due to the high usage of the resin, although the gloves have good performance before aging and are more durable, the tensile stress after aging is high, the elongation is greatly reduced, and the soft feel of the gloves after aging is greatly reduced.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims (10)

1. A nitrile latex composition, characterized in that it comprises the following components by weight: 100 parts of nitrile rubber latex, 1 to 3 parts of triazine-formaldehyde condensate resin and 0.3 to 0.7 parts of vulcanizing agent; The acrylonitrile content of the nitrile rubber latex is 28% to 35%. 2. The nitrile latex composition according to claim 1, characterized in that the mass ratio of the triazine-formaldehyde condensate resin to the vulcanizing agent is 2 to 10:1. 3. The nitrile latex composition according to claim 1, wherein the vulcanizing agent is sulfur or tetramethylthiuram disulfide. 4. The nitrile latex composition according to claim 1, further comprising at least one of an activating agent, a accelerator, an antioxidant, and a coloring agent. 5. The nitrile latex composition according to claim 3 is characterized in that, by weight, it also includes 0 to 0.4 parts of an active agent, 0 to 0.7 parts of a accelerator, 0 to 0.5 parts of an antioxidant and 0 to 0.8 parts of a pigment. 6. The nitrile latex composition according to claim 4 or 5, characterized in that the activator is a divalent metal oxide; preferably, the activator is magnesium oxide or zinc oxide; the accelerator is a zinc salt of thiocarbamate or thiazole; the antioxidant is at least one of phenols, amines, phosphites, and hindered phenol antioxidants. 7. A nitrile glove, characterized in that it is made from the nitrile latex composition according to any one of claims 1 to 5. 8. A method for preparing nitrile gloves, characterized in that it comprises the following steps: (1) taking the components of the nitrile latex composition according to any one of claims 1 to 6, mixing them to obtain a premixed nitrile latex; (2) Immerse the hand model in a coagulant; then take out the hand model and dry it; (3) immersing the hand mold into the obtained premixed nitrile latex, then taking out the hand mold and drying it; (4) leaching treatment, drying and vulcanization molding; (5) After chlorination treatment, demoulding is completed. 9. The method for preparing nitrile gloves according to claim 8, characterized in that in step (2), the coagulant is calcium nitrate or calcium chloride. 10. Use of the nitrile latex composition according to any one of claims 1 to 6, the nitrile gloves according to claim 7, and the preparation method according to claim 8 or 9 in medical gloves.