Flame-retardant rubber gloves and preparation method thereof
阅读说明：本技术 一种阻燃橡胶手套及其制备方法 (Flame-retardant rubber gloves and preparation method thereof ) 是由 周煜程 周星余 孙永峰 于 2021-09-03 设计创作，主要内容包括：本发明涉及一种阻燃橡胶手套及其制备方法,其包括：S1、将分散剂、乳化剂、水、阻燃剂按比例混合,搅拌并配合超声分散,得到阻燃剂乳液；阻燃剂为氢氧化铝、氢氧化镁、包覆红磷、改性聚磷酸铵、季戊四醇、三聚氰胺、膨胀石墨中的一种或两种以上的组合；S2、按质量份数计,将100份的胶乳进行搅拌,然后将1-5份表面活性剂、0.5-2份硫化剂、1-5份促进剂A、1-3份促进剂B、40-80份阻燃剂乳液、0.5-2份活性剂、1-6份增稠剂加到胶乳中混合均匀,得到含阻燃剂的胶料；S3、将棉手套胚或经凝固剂处理的针织手套胚浸渍前述胶料；S4、硫化制得阻燃橡胶手套。所述阻燃手套具有高阻燃性、燃烧不产生有毒烟尘/气体,有良好耐磨性和灵巧性,满足高温高热环境的使用要求。(The invention relates to a flame-retardant rubber glove and a preparation method thereof, wherein the flame-retardant rubber glove comprises the following steps: s1, mixing the dispersing agent, the emulsifier, the water and the flame retardant in proportion, stirring and matching with ultrasonic dispersion to obtain a flame retardant emulsion; the flame retardant is one or the combination of more than two of aluminum hydroxide, magnesium hydroxide, coated red phosphorus, modified ammonium polyphosphate, pentaerythritol, melamine and expanded graphite; s2, stirring 100 parts of latex according to parts by weight, and then adding 1-5 parts of surfactant, 0.5-2 parts of vulcanizing agent, 1-5 parts of accelerator A, 1-3 parts of accelerator B, 40-80 parts of flame retardant emulsion, 0.5-2 parts of active agent and 1-6 parts of thickening agent into the latex to be uniformly mixed to obtain a sizing material containing the flame retardant; s3, dipping the cotton glove blank or the knitted glove blank treated by the coagulant into the sizing material; and S4, vulcanizing to obtain the flame-retardant rubber glove. The flame-retardant gloves have high flame retardance, do not generate toxic smoke dust/gas during combustion, have good wear resistance and flexibility, and meet the use requirements of high-temperature and high-heat environments.)
1. A preparation method of flame-retardant rubber gloves is characterized by comprising the following steps:
s1 preparation of flame retardant emulsion
Mixing a dispersing agent, an emulsifying agent, water and a flame retardant in proportion, stirring and matching with ultrasonic dispersion to obtain a flame retardant emulsion with a certain consistency; the flame retardant is one or the combination of more than two of aluminum hydroxide, magnesium hydroxide, coated red phosphorus, modified ammonium polyphosphate, pentaerythritol, melamine and expanded graphite;
s2 preparation of sizing material containing flame retardant
According to the mass parts, 100 parts of latex is stirred in a container for a preset time, and then 1-5 parts of surfactant, 0.5-2 parts of vulcanizing agent, 1-5 parts of accelerator A, 1-3 parts of accelerator B, 40-80 parts of flame retardant emulsion, 0.5-2 parts of active agent and 1-6 parts of thickening agent are added into the latex and uniformly mixed to obtain a sizing material containing the flame retardant;
s3, gum dipping
Dipping the glove blank once or twice with the size prepared by step S2;
the glove blank is a cotton flannel glove blank or a knitted glove blank; when the glove blank is a cotton flannel glove blank, the glove blank is directly dipped once or twice with the size prepared in step S2; when the glove blank is a knitted glove blank, the glove blank is heated first, then dipped with a coagulant, taken out of the coagulant and then dipped once or twice with the sizing material prepared in step S2;
and S4, vulcanizing and drying to obtain the flame-retardant rubber gloves.
2. The method according to claim 1, wherein in S1, the flame retardant is a combination of aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite, or a combination of ammonium polyphosphate, pentaerythritol and melamine and expanded graphite; in the flame retardant emulsion, the mass concentration of the flame retardant is 35-45%.
3. The method according to claim 2, wherein in S1, the flame retardant is a combination of aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite, and wherein the aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite are mixed in a ratio of 10:2: 1.
4. The production method according to any one of claims 1 to 3, wherein, in S1, the flame retardant is modified in advance with a silane coupling agent by: adjusting the pH value of a silane coupling agent and absolute ethyl alcohol to 3-5, heating at a constant temperature of 50-80 ℃, hydrolyzing, adding a flame retardant, stirring or oscillating at a constant temperature of 50-80 ℃, and drying the obtained solid, namely the silane coupling agent modified flame retardant for later use.
5. The method according to claim 1, wherein in S1, the mass concentration of the flame retardant in the flame retardant emulsion is 40%; in S2, when preparing a flame retardant-containing rubber compound, the amount of the flame retardant emulsion added was 60 parts by weight.
6. The method of claim 1, wherein in S2, the compound is formulated by: firstly, stirring latex for a period of time, then respectively adding a surfactant, a vulcanizing agent, an accelerator A, an accelerator B, a flame retardant emulsion and an activator into the latex, stirring and heating for prevulcanization treatment, and after prevulcanization is finished, adding a thickening agent to adjust the viscosity to be 1500-3500 mPa.s.
7. The method according to claim 1, wherein 1 to 5 parts by mass of the antifrost agent is added to the size in S2.
8. The preparation method according to claim 1, wherein in S2, when preparing the compound containing the flame retardant, the adding amount of the flame retardant aluminum hydroxide is controlled to make the content of the vulcanized rubber glove in the rubber layer be 10-15%; or when preparing the sizing material containing the flame retardant, controlling the addition of the flame retardant ZB to ensure that the content of the vulcanized rubber layer of the flame-retardant rubber gloves is 30-40%.
9. The method according to claim 7, wherein in S2, the latex is one or more of natural latex, butadiene latex, chloroprene latex, butyl latex, ethylene propylene diene monomer latex, and styrene butadiene latex; in the preparation process of the dipping sizing material, adding a surfactant, a vulcanizing agent, an accelerator A, an accelerator B, a flame retardant emulsion and an active agent into latex, heating to 60-80 ℃, and pre-vulcanizing for 15-45 min;
in S3, the glove blank is woven by flame-retardant nylon and flame-retardant polyester.
10. A flame-retardant rubber glove produced by the production method according to any one of claims 1 to 9.
Technical Field
The invention relates to the technical field of labor protection gloves, in particular to a flame-retardant rubber glove and a preparation method thereof.
Background
Rubber gloves are the most common labor gloves. Since most of the rubber polymers have C, H as a main constituent element, they are extremely flammable. The application of the labor protection gloves relates to the aspect of industrial production, and rubber labor protection gloves are needed in various industries, especially in high-temperature and high-heat environments. After the rubber is burnt, thick smoke and toxic gas can be generated, which threatens the life health and property safety of people and burns hands.
Therefore, reducing the flammability of rubber gloves and reducing the toxic fumes/gases generated during burning are important measures to improve the quality of such glove products. However, flame retardancy of rubber has been a problem.
At present, almost all rubber flame-retardant gloves on the market are chloroprene rubber gloves, but the chloroprene rubber gloves are expensive in price and high in material cost, and the price of the chloroprene rubber gloves is about 2 times of that of natural rubber or nitrile rubber. Most of the currently available flame retardants are halogen flame retardants. Although the halogen flame retardant has the remarkable advantages of high flame retardant efficiency, small addition amount, low price and the like, the halogen flame retardant can generate a large amount of smoke during combustion and release toxic and corrosive gas (hydrogen halide) to seriously harm human health. In addition, how to reduce the flammability of the rubber gloves and reduce the toxic smoke/gas generated in the combustion process, and simultaneously give consideration to the wear resistance and wearing flexibility of the rubber gloves, and meet the application requirements in various aspects is a difficult problem to be solved urgently.
Disclosure of Invention
Technical problem to be solved
In view of the above disadvantages and shortcomings of the prior art, the present invention provides a method for preparing flame retardant rubber gloves, which is used to prepare flame retardant rubber gloves with excellent wear resistance and wearing flexibility, high flame retardancy, and no generation of toxic smoke and toxic gas even if burned at high temperature, so as to meet the use requirements of high temperature and high heat production environment.
(II) technical scheme
In order to achieve the purpose, the invention adopts the main technical scheme that:
in a first aspect, the present invention provides a method for preparing a flame retardant rubber glove, comprising:
s1 preparation of flame retardant emulsion
Mixing a dispersing agent, an emulsifying agent, water and a flame retardant in proportion, stirring and matching with ultrasonic dispersion to obtain a flame retardant emulsion with a certain consistency; the flame retardant is one or the combination of more than two of aluminum hydroxide (ATH), Zinc Borate (ZB), magnesium hydroxide, coated red phosphorus (P4), modified ammonium polyphosphate, pentaerythritol, melamine and expanded graphite (T-EG);
s2 preparation of sizing material containing flame retardant
According to the mass parts, 100 parts of latex is stirred in a container for a preset time, and then 1-5 parts of surfactant, 0.5-2 parts of vulcanizing agent, 1-5 parts of accelerator A, 1-3 parts of accelerator B, 40-80 parts of flame retardant emulsion, 0.5-2 parts of active agent and 1-6 parts of thickening agent are added into the latex and uniformly mixed to obtain a sizing material containing the flame retardant;
s3, gum dipping
Dipping the glove blank once or twice with the size prepared by step S2;
the glove blank is a cotton flannel glove blank or a knitted glove blank; when the glove blank is a cotton flannel glove blank, the glove blank is directly dipped once or twice with the size prepared in step S2; when the glove blank is a knitted glove blank, the glove blank is heated firstly, then is impregnated with the coagulant, and is impregnated once or twice with the sizing material prepared in the step S2 after being taken out of the coagulant;
and S4, vulcanizing and drying to obtain the flame-retardant rubber gloves.
According to a preferred embodiment of the present invention, in S1, the flame retardant is a combination of aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite, or a combination of ammonium polyphosphate, pentaerythritol and melamine and expanded graphite; in the flame retardant emulsion, the mass concentration of the flame retardant is 35-45%.
Preferably, in S1, the flame retardant is a combination of aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite, and wherein the aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite are mixed in a ratio of 10:2: 1.
According to a preferred embodiment of the present invention, in S1, the flame retardant is modified by a silane coupling agent in advance, and the modification method is as follows: adjusting the pH value of a silane coupling agent and absolute ethyl alcohol to 3-5, heating at a constant temperature of 50-80 ℃, hydrolyzing, adding a flame retardant, stirring or oscillating at a constant temperature of 50-80 ℃, and drying the obtained solid, namely the silane coupling agent modified flame retardant for later use. Wherein the mass ratio of the flame retardant to the silane coupling agent is 100: 5-10. The silane coupling agent may be KH550 or KH 570.
In the processes of preparing rubber materials and pre-vulcanizing, the flame retardant can be connected with latex molecules through chemical bonds by a coupling agent and grafted to the latex molecules, and compared with the flame retardant which is only mixed in rubber in a physical mode, the firmness and the uniformity of dispersion of the flame retardant in the rubber can be improved through the chemical bonds, so that the flame retardance, the durability, the wear resistance and the like of the rubber gloves are effectively improved.
According to a preferred embodiment of the present invention, in S1, the dispersant is one or a combination of several of sodium methylene dinaphthalene sulfonate (dispersant NF), sodium sulfonate, and sodium dodecyl benzene sulfonate.
According to a preferred embodiment of the present invention, in S1, the emulsifier is one or a combination of several of casein, peregal and sodium alkyl sulfate.
According to a preferred embodiment of the present invention, the flame retardant emulsion is added in an amount of 60 parts by weight in S2.
According to a preferred embodiment of the present invention, in S2, the compound is prepared by: firstly, stirring latex for a period of time, then respectively adding a surfactant, a vulcanizing agent, an accelerator A, an accelerator B, a flame retardant emulsion and an activator into the latex, stirring and heating for prevulcanization treatment, and after prevulcanization is finished, adding a thickening agent to adjust the viscosity to be 1500-3500 mPa.s.
In the process of preparing the rubber material, the flame retardant and the like are added into the rubber latex to be heated (60-80 ℃ and precured for 15-45min) for precuring treatment, so that cross-linked networks are generated among local active groups of the rubber latex molecules, and part of the flame retardant (especially the flame retardant modified by the silane coupling agent) is uniformly dispersed in the rubber material and is grafted, wound/wrapped on the rubber latex molecules.
According to a preferred embodiment of the present invention, in S2, in order to prevent the flame retardant added to the size from being precipitated in the form of powder during the later use of the glove finished product, 1 to 5 parts by mass of an antifrost agent is further added to the size.
Preferably, the antifrost agent consists of 25 percent of microcrystalline wax, 30 percent of polyethylene glycol, 10 percent of No. 58 paraffin emulsifier, 10 percent of brominated epoxy resin, 1 percent of hydrocarbon resin and 24 percent of nano-silicon dioxide.
According to the preferred embodiment of the invention, in S2, when preparing the rubber compound containing the flame retardant, the adding amount of the flame retardant aluminum hydroxide is controlled, so that the content of the vulcanized rubber layer of the flame-retardant rubber glove is 10-15%; or when preparing the sizing material containing the flame retardant, controlling the addition of the flame retardant ZB to ensure that the content of the vulcanized rubber layer of the flame-retardant rubber gloves is 30-40%.
According to the preferred embodiment of the present invention, step S3 includes the steps of dipping and surface treatment, which includes the following steps:
dipping the glove blank once with the sizing prepared by step S2, and then with a wrinkling agent to prepare a flame retardant rubber wrinkled glove; or:
soaking the glove blank once with the sizing material prepared in the step S2, then dripping and homogenizing the sizing material, putting the glove blank into a primary oven to pre-dry the glove glue layer to 4-7, soaking the glove blank again with the sizing material prepared in the step S2 for the second time, and spraying salt to prepare the flame-retardant rubber frosted glove.
Preferably, the wrinkling agent consists of 100 parts by weight of swelling oil agent, 10-40 parts by weight of demulsifying oil agent and 1-5 parts by weight of coagulation accelerator agent, wherein the swelling oil agent is one or any combination of the toluene, xylene, chloroform, dichloromethane and acetone; the demulsifying oil agent is one or any combination of liquid low-carbon alcohols with the carbon number below 10; the gel accelerator is one or a combination of several of formic acid, acetic acid, benzoic acid and phenylacetic acid.
Preferably, the salt is one or a mixture of sodium chloride, sodium sulfate, sodium sulfite and sodium carbonate.
According to the preferred embodiment of the present invention, in S4, the vulcanization drying includes pre-drying at a low temperature and then vulcanizing at a high temperature to obtain the finished flame retardant rubber glove. Preferably, the low-temperature pre-drying temperature is 60-90 ℃, the drying time is 15-40min, the high-temperature vulcanization temperature is 100-140 ℃, and the vulcanization time is 1-3 h.
S2, preparing the components of the impregnating compound, except the flame retardant, and describing the following:
latex: the latex in the invention is one or more of natural latex, Tianjia latex, butyronitrile latex, cis-butadiene latex, neoprene latex, butyl latex, ethylene propylene diene monomer latex and butadiene styrene latex. Among them, natural latex is most preferable, on one hand, natural latex is environment-friendly, easy to degrade, biocompatible and suitable for special occasions (such as medical occasions), and on the other hand, natural latex has high wet gel strength, and after an inorganic reinforcing agent is added, the performance (mainly strength) of latex is not greatly influenced, but other latexes are greatly influenced. The viscosity of the rubber material can be designed according to the rubber thickness of the finished product, the more the rubber is coated, the larger the rubber thickness of the glove product is, the better the flame retardant performance is, but the too thick rubber can weaken the wearing comfort and the operation flexibility, so that the preferable range is 1500mPa.s-3500 mPa.s. Because of the addition of the inorganic flame retardant in the rubber material, the rubber hanging (adhesion tightness with glove blanks) performance of the rubber material can be weakened to a certain extent, so that the gloves can be prepared by adopting twice gum dipping to ensure that the rubber reaches the preset thickness and have better protection performance.
Surfactant (b): in the present invention, the surfactant is preferably an anionic surfactant or a nonionic surfactant, and specifically, may be one or a combination of several of dioctyl sodium sulfosuccinate, sodium alkenyl sulfonate, sodium hexadecyl sulfate, sodium octadecyl sulfate, sodium dodecyl benzene sulfonate, peregal, etc. Different surfactants have different effects on the conjunctival velocity of the latex and different effects on the coagulation of the latex, so that the dosage needs to be adjusted according to actual conditions.
Accelerator (b): in the invention, the accelerator A and the accelerator B are different vulcanization accelerators, and are respectively selected from one or a combination of several of thiazoles (DM), dithiocarbamates (ZDC, BZ), sulfenamides (CZ) and thiurams (TMTD).
When the impregnated rubber material is prepared, the invention uses two different accelerators, the accelerating mechanisms and speeds of the different accelerators on vulcanization are different, and the two accelerators are combined for use, so that the vulcanization speed is smoother, the performances (wear resistance and puncture resistance) of each part of the rubber are more uniform and stable, and the overall performance is better.
Active agent(s): in the present invention, the activator is a sulfurized activator, and can be selected from zinc oxide, zinc carbonate or zinc stearate. The activator can improve the vulcanization degree, promote the vulcanization speed and shorten the vulcanization time.
Vulcanizing agent: in the invention, the vulcanizing agent is sulfur, a vulcanizing agent DCP, a vulcanizing agent PDM, a dithiocarbamic acid salt, thiazole, a thiuram vulcanizing agent and the like.
Thickening agent: in the invention, the thickening agent is also called as a gelling agent and is a substance capable of increasing the viscosity of latex and liquid, and the thickening agent can improve the viscosity of a system, so that the system is kept in a uniform and stable suspension state or an emulsion state or forms gel; most thickeners combine an emulsifying action. The thickener is one or more selected from casein, hydroxypropyl methylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol.
In S3, before dipping, the knitted glove blank is dipped with a coagulant. Wherein the coagulant can be bivalent calcium solution of methanol or ethanol, butanol, or solution of methanol, ethanol, butanol and acid, or mixed solution of alcohol, acid, and calcium, with concentration of 1% -5%.
S3, the glove blanks are woven by flame-retardant nylon and flame-retardant polyester, so that the flame retardant performance of the gloves is further enhanced, and the hand protection effect of the gloves is improved.
In a second aspect, the invention provides a flame-retardant rubber glove, which is prepared by the preparation method in any one of the above embodiments.
(III) advantageous effects
The invention has the beneficial effects that:
(1) the flame retardant used in the invention is one or more of aluminum hydroxide, magnesium hydroxide, coated red phosphorus, modified ammonium polyphosphate, pentaerythritol, melamine or expanded graphite, and the like, and the flame retardant is a halogen-free flame retardant, so that the flame retardant has good flame retardant property, generates little toxic smoke dust/gas after combustion, and reduces secondary damage generated by rubber gloves combustion.
(2) According to the invention, the flame retardant, the dispersing agent, the emulsifying agent and the water are firstly prepared to obtain the flame retardant emulsion with a certain consistency, so that the flame retardant is uniformly dispersed in the emulsion, and the flame retardant emulsion is beneficial to improving the flame retardant property of the flame-retardant rubber gloves. Particularly, when the flame retardant is mixed with a plurality of different flame retardants for use, the flame retardant emulsion with certain consistency is emulsified, so that the problems of sinking, layering and the like of the flame retardants with different particle sizes/specific gravities can be prevented, and the uniformity of a flame retardant system is ensured.
(3) More preferably, the flame retardant is modified with a silane coupling agent, and the flame retardant is chemically grafted to latex molecules by the modification, so that the distribution uniformity and bonding firmness of the flame retardant in the latex are improved, and the flame retardant performance, durability and wear and puncture resistance of the rubber are improved (when the flame retardant is directly physically mixed, the wear and puncture resistance of the rubber is deteriorated after coagulation).
(4) The flame retardant is preferably a composite flame retardant formed by mixing aluminum hydroxide, coated red phosphorus and expanded graphite according to a ratio of 10:2: 1. The flame retardant is prepared into 40% emulsion, when the rubber glove is used, the rubber glove is prepared according to the proportion of 100 parts of latex and 60 parts of flame retardant emulsion, and the flame retardant performance, the wear resistance and the wearing softness (the softness determines the wearing dexterity) of the rubber glove finished product are all optimal.
(5) In the preparation process of the dipping rubber material, a surfactant, a vulcanizing agent, an accelerator A, an accelerator B, a flame retardant emulsion, an active agent (zinc oxide/zinc carbonate/zinc stearate) and the like are added into latex to be stirred and heated for prevulcanization treatment, so that latex molecules generate a local cross-linked network, flame retardant particles are uniformly dispersed and wound on the latex molecules (the flame retardant modified by a coupling agent can be grafted on the latex molecules), and the combination firmness of the flame retardant in the latex and the flame retardance and the durability of gloves are improved.
Detailed Description
For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail below with reference to specific embodiments.
The flame retardant used in the invention is one or more of aluminum hydroxide, magnesium hydroxide, coated red phosphorus, modified ammonium polyphosphate, pentaerythritol, melamine or expanded graphite, and the like, and the flame retardants are halogen-free environment-friendly flame retardants and have the following advantages.
The aluminum hydroxide/magnesium hydroxide is an environment-friendly flame retardant (low smoke and halogen-free) and smoke suppressor, can improve the caking property (the solid material prevents the spread and corrosion of flame by a caking carbon layer), the limiting oxygen index and reduce the smoke density of the low smoke and halogen-free rubber. The aluminum hydroxide/magnesium hydroxide and other flame retardants have synergistic effect. The decomposition temperature of the aluminum hydroxide is 180 ℃, the decomposition temperature of the magnesium hydroxide is 350 ℃, and the vulcanization temperature of the glove is not more than 140 ℃, so that the two flame retardants can be suitable for use. In the aspect of carbonization performance, magnesium hydroxide is slightly better than aluminum hydroxide, but the cost of the aluminum hydroxide is low, the rubber gloves prepared by mixing the magnesium hydroxide with rubber are softer and more comfortable in hand feeling and good in low temperature resistance, and the aluminum hydroxide also has the functions of reinforcement (wear resistance) and frost prevention, so that the additional value of the rubber gloves is better improved.
The coated red phosphorus is a superfine coated red phosphorus flame retardant prepared by adopting a coating technology, so that the activity of the red phosphorus is reduced, the compatibility of the red phosphorus is improved, the moisture absorption problem of red phosphorus powder used as a flame retardant is solved, the high content of effective flame retardant components is kept, and the fire-resistant temperature is increased. The coated red phosphorus can be well dispersed in the latex.
The expandable graphite can play a better role in flame retardance on the premise of not influencing the basic performance and appearance of the glove. Modified ammonium polyphosphate is combined with expandable graphite. The modified ammonium polyphosphate is an acidic polymer, forms phosphoric acid when meeting water, reduces the pH value of a latex mixture, compresses double electric layers on the surface of colloidal particles, promotes the dissolution of zinc oxide and the formation of a zinc-ammonia complex, quickly gelatinizes the latex, and ensures that the expandable graphite flame retardant is uniformly dispersed in a rubber material and a product has good flame retardant property by the gelatinization process.
The ammonium polyphosphate, the melamine and the pentaerythritol are matched, when the gloves are subjected to the action of high temperature and flame, severe expansion, carbonization and foaming are carried out, the volume of the sponge carbon layer is enlarged to dozens of times of that of the incombustible sponge carbon layer, the heat transfer can be effectively delayed, and the gloves play a good role in protecting the inner rubber layer/glove blank.
Example 1
The embodiment provides a preparation method of a flame-retardant rubber glove, which comprises the following steps:
(1) preparing fire retardant emulsion
Preparing 10 parts of deionized water, 2 parts of dispersing agent NF, 2 parts of sodium dodecyl sulfate and 1 part of casein into a dispersion liquid, and mixing ammonium polyphosphate, pentaerythritol, melamine and expanded graphite according to a ratio of 2:1:1 to obtain 10 parts of composite flame retardant, adding the composite flame retardant into the dispersion, stirring for 10min and carrying out ultrasonic dispersion for 3min to prepare flame retardant emulsion with the flame retardant concentration of 40%.
(2) Compounding of rubber material containing flame retardant
According to the mass parts, 100 parts of natural latex is stirred in a container for 10min, then 1 part of sodium dodecyl benzene sulfonate, 2 parts of sulfur, 2 parts of TT (accelerator A), 2 parts of ZDC (accelerator B), 60 parts of flame retardant emulsion, 1 part of zinc oxide, 2 parts of antifrost agent (consisting of 25 mass percent of microcrystalline wax, 30 mass percent of polyethylene glycol, 10 mass percent of 58# paraffin emulsifier, 10 mass percent of brominated epoxy resin, 1 mass percent of hydrocarbon resin, 24 mass percent of nano-silicon dioxide) and 2.5 parts of casein are uniformly mixed, heated to 65 ℃ and preserved for 20min for prevulcanization, and a sizing material containing the flame retardant is obtained, wherein the viscosity is 2200mPa.
(3) Impregnation
Sleeving a 13-needle flame-retardant polyester glove blank on a hand mould, heating to 50 ℃, soaking in 2.5% of calcium chloride methanol coagulant, and then soaking in the glue stock prepared in the step (2). Pre-drying the glove rubber layer to 7 dry in an oven at 80 ℃, dipping the rubber material prepared in the step (2), spraying salt (sodium sulfite) on the glove surface rubber layer according to a sanding process, and soaking in normal temperature water.
(4) Vulcanizing and drying
Baking at 90 ℃ for 30min, and vulcanizing at 120 ℃ for 2h to obtain the finished product of the flame-retardant rubber glove.
Example 2
The embodiment provides a preparation method of a flame-retardant rubber glove, which comprises the following steps:
(1) preparing fire retardant emulsion
Preparing 10 parts of deionized water, 2 parts of dispersing agent NF, 2 parts of sodium dodecyl sulfate and 1 part of casein into dispersion liquid according to parts by weight, mixing magnesium hydroxide, coated red phosphorus and expanded graphite according to the mass ratio of 10:2:1 to obtain 10 parts of flame retardant, adding the flame retardant into the dispersion liquid, stirring for 10min and performing ultrasonic dispersion for 3min to prepare flame retardant emulsion with the flame retardant concentration of 40%.
(2) Compounding of rubber material containing flame retardant
According to the mass parts, 100 parts of natural latex is stirred in a container for 10min, then 1 part of sodium lauryl sulfate, 2 parts of sulfur, 2 parts of TT (accelerant A), 2 parts of ZDC (accelerant B), 60 parts of flame retardant emulsion, 2 parts of zinc oxide, 2 parts of antifrost agent (the same above) and 3 parts of PVP are uniformly mixed, heated to 65 ℃ and preserved for 20min for prevulcanization, and the rubber material containing the flame retardant is obtained, wherein the viscosity is 2400mPa.
(3) Impregnation
Sleeving a 13-needle flame-retardant polyester glove blank on a hand mould, heating to 50 ℃, soaking in 2.5% of calcium chloride methanol coagulant, and then soaking in the glue stock prepared in the step (2). Pre-drying the glove rubber layer to 7 dry in an oven at 80 ℃, dipping the rubber material prepared in the step (2), spraying salt (sodium sulfite) on the glove surface rubber layer according to a sanding process, and soaking in normal temperature water.
(4) Vulcanizing and drying
Baking at 90 ℃ for 30min, and vulcanizing at 120 ℃ for 2h to obtain the finished product of the flame-retardant rubber glove.
Example 3
This example provides a method for preparing a flame retardant rubber glove, which is different from example 2 only in the (1) th step in that a flame retardant is composed of aluminum hydroxide, coated red phosphorus and expanded graphite mixed in a mass ratio of 20:13: 2.
Example 4
This example provides a method for preparing a flame-retardant rubber glove, which is different from example 3 only in the (1) th step in that a flame retardant is composed of aluminum hydroxide, coated red phosphorus and expanded graphite mixed in a mass ratio of 10:2: 1.
Example 5
This example provides a method for preparing a flame retardant rubber glove, which is different from example 3 only in the step (1) in that a flame retardant is composed of aluminum hydroxide, coated red phosphorus and expanded graphite mixed in a mass ratio of 5:3: 2.
Example 6
This example provides a method for preparing a flame retardant rubber glove, which is different from example 2 only in the step (1) in that a flame retardant is composed of modified ammonium polyphosphate and expandable graphite mixed in a mass ratio of 6: 4.
Example 7
This example provides a method for preparing a flame-retardant rubber glove, which is different from example 2 only in the (1) th step in that a flame retardant is composed of ammonium polyphosphate, melamine and pentaerythritol mixed in a mass ratio of 4:4: 2.
Example 8
This example provides a method for preparing flame retardant rubber gloves, which is different from example 4 only in the step (1), the aluminum hydroxide, the coated red phosphorus and the expanded graphite in the flame retardant are previously modified with KH 570. The modification method comprises the following steps: mixing silane coupling agent and absolute ethyl alcohol according to a ratio of 1:5, adjusting pH to 4, heating and maintaining the constant temperature at 70 ℃ for 30min for hydrolysis, then adding compound flame retardant, oscillating at the constant temperature of 7 ℃, filtering, and drying for later use.
Example 9
This example provides a method for preparing flame retardant rubber gloves, which differs from example 4 only in step (2), using 40 parts of flame retardant emulsion in the formulation of the compound.
Example 10
This example provides a method for preparing flame retardant rubber gloves, which differs from example 4 only in step (2), using 80 parts of flame retardant emulsion in the formulation of the compound.
Example 11
This example provides a method for preparing a flame retardant rubber glove, which is different from example 4 only in the step (1), wherein the flame retardant is prepared from ammonium polyphosphate, pentaerythritol, melamine and expanded graphite according to the ratio of 2:1: 1:1 by mass ratio.
Example 12
This example provides a method for preparing a flame retardant rubber glove, which is different from example 4 only in the step (3):
sleeving a 13-needle flame-retardant polyester glove blank on a hand mold, heating to 50 ℃, soaking in 2.5% of calcium chloride methanol coagulant, then soaking in the rubber material prepared in the step (2), dripping and homogenizing, and soaking in a wrinkling agent, wherein the wrinkling agent comprises the following components: 100 parts by weight of chloroform, 25 parts by weight of ethanol and 4 parts by weight of benzoic acid, soaking for 1min, and then sending to the next step for vulcanization to obtain the flame-retardant rubber wrinkle glove.
To further illustrate the technical effect and the advancement of the solution of the invention, the following comparative examples were obtained by changing some of the features of the solution of the invention.
Comparative example 1
Comparative example 1 is based on example 4, with the expanded graphite removed.
Comparative example 2
In the comparative example, on the basis of example 2, the step of preparing the flame retardant emulsion is removed, and 24 parts by weight of the flame retardant (compounded by magnesium hydroxide, coated red phosphorus and expanded graphite in a mass ratio of 10:2: 1) are added to 100 parts of the natural latex to prepare the rubber material.
Comparative example 3
In the comparative example, on the basis of example 2, when the compound containing the flame retardant is prepared in step (2), only the components constituting the compound are stirred and mixed without heating for precuring.
Comparative example 4
In the comparative example, on the basis of example 8, when the compound containing the flame retardant was prepared in step (2), only the components constituting the compound were stirred and mixed without heating for precuring.
Comparative example 5
Comparative example 5 is based on example 4, with the component of the antifrost removed.
The fire ratings of the rubber flame retardant gloves of examples 1-12 and comparative examples 1-5 were tested according to EN407 fire-protective glove industry standard as follows:
group of
Flame retardant rating
Duration of flame extension/s
Afterglow (smoldering) time/s
Example 1
4
Self-extinguishing when out of fire
3s
Example 2
4
Self-extinguishing when out of fire
1.5s
Example 3
4
Self-extinguishing when out of fire
1.2s
Example 4
4
Self-extinguishing when out of fire
1s
Example 5
4
Self-extinguishing when out of fire
1.5s
Example 6
4
Self-extinguishing when out of fire
2s
Example 7
4
Self-extinguishing when out of fire
2s
Example 8
4
Self-extinguishing when out of fire
0.8s
Example 9
4
Self-extinguishing when out of fire
1.5s
Example 10
4
Self-extinguishing when out of fire
0.8s
Example 11
4
Self-extinguishing when out of fire
2.5s
Example 12
4
Self-extinguishing when out of fire
1s
(continuation table)
Group of
Flame retardant rating
Duration of flame extension/s
Afterglow (smoldering) time/s
Example 4
4
Self-extinguishing when out of fire
1s
Comparative example 1
1
＞20s
Without requirement
Comparative example 2
2
9.5s
Without requirement
Comparative example 3
3
5s
Without requirement
Comparative example 4
3
4.5s
Without requirement
Comparative example 5
4
Self-extinguishing when out of fire
3s
The abrasion resistance and softness of the flame retardant gloves of examples 1-12 were tested according to EN388 glove industry standards as follows:
wear resistance
Softness of wearing
Dexterity
Surface effects
Example 1
Grade 3 (2320 to 2530r)
Softness
Dexterity
No powder precipitation
Example 2
Stage 3 (>6500)
Is softer
Is more smart
No powder precipitation
Example 3
Stage 3 (>7000)
Softness
Dexterity
No powder precipitation
Example 4
Stage 4 of (>8000)
Softness
Dexterity
No powder precipitation
Example 5
Stage 4 of (>8000)
Is softer
Is more smart
No powder precipitation
Example 6
Grade 2 (1500 to 2000r)
Softness
Dexterity
No powder precipitation
Example 7
Grade 2 (1500 to 2000r)
Softness
Dexterity
No powder precipitation
Example 8
Stage 4 of (>8000)
Softness
Dexterity
No powder precipitation
Example 9
Grade 3 (2320 to 2530r)
Softness
Dexterity
No powder precipitation
Example 10
Stage 4 of (>8000)
Hair hardness
Poor dexterity
No powder precipitation
Example 11
Grade 3 (2200 to 2450r)
Softness
Dexterity
No powder precipitation
Example 12
Grade 2 (1000 to 1500r)
Softness
Dexterity
No powder precipitation
Comparative example 5
Stage 3 (>7000)
Softness
Dexterity
With graphite and powder separated out
Note: the abrasion resistance test grade and the number of revolutions are as follows:
grade
1
2
3
4
Number of revolutions
100～500
500～2000
2000～8000
>8000
The wearing softness sequence is as follows: softness is better than softer and softer is better than hair-hard; dexterity is better than dexterity, and dexterity is better than dexterity and is poorer.
Wherein, the expanded graphite is removed from the flame retardant in the comparative example 1, so that the flame retardant grade of the glove product is obviously reduced. Comparative example 2 does not carry out emulsion dispersion on the compound flame retardant mixed with different flame retardants, and the flame retardants are layered and unevenly distributed, so that the flame retardant grade of glove products is reduced. Comparative examples 3-4 did not pre-cure the compound during the formulation, resulting in a slight decrease in the flame retardant rating of the glove product.
In comparative example 5, the frost prevention agent was removed, so that the surface of the finished product could be touched to separate out powder such as expanded graphite. Not only affects the cleanliness of the glove surface and limits the application occasions of the gloves, but also can cause the rapid reduction of the flame retardant capability of the rubber gloves due to the precipitation of inorganic flame retardant powder.
Wherein, the compound of aluminum hydroxide/magnesium hydroxide, coated red phosphorus and expanded graphite is used as a flame retardant in the examples 2, 3, 4, 5, 8, 9 and 10, and the prepared glove products are superior to the examples 1, 6-7 and 11 in the aspects of flame retardance, wear resistance, softness and the like; in particular, when aluminum hydroxide, coated red phosphorus and expanded graphite were used in a 10:2:1 combination, the gloves produced were most excellent in flame retardancy, abrasion resistance, softness and the like (examples 4 and 8). The rubber gloves prepared in example 8 are superior to example 4 in durability, mainly because the flame retardant in example 8 can be more firmly grafted in latex molecules after being modified by the coupling agent, so that the flame retardant is retained in the rubber layer and is not easy to separate out along with the length of the service time. In addition, the gloves are frosted when left wet for a long time due to the use of aluminum hydroxide. The amount of the flame retardant used in example 10 was higher, and although the glove flame retardancy was better, the glove was harder and less flexible than that of example 4. Comparing example 4 with example 12, the frosted gloves prepared by two times of dipping are superior to the wrinkled gloves dipped only once.
In summary, the flame-retardant glove products prepared in examples 1-12 of the present invention do not burn or partially burn at 350 ℃ of 300-.
In addition, on the basis of example 2, if the compound is prepared, the flame retardant only uses aluminum hydroxide (ATH), the addition amount is changed, and the influence of the mechanical property of the natural latex vulcanized rubber film is tested, and the results are shown in the following table:
therefore, when aluminum hydroxide (ATH) is used, it is not preferable to use it in an excessive amount, and it is preferable to use it in combination with other flame retardants, which may otherwise cause a decrease in the tear strength, tensile stress, tensile strength, elongation at break, etc. of the glove as a whole. Preferably, the content of aluminium hydroxide ATH in the finished rubber is controlled to be about 10-15%, preferably not more than 20%.
Further, based on example 2, if the compound was prepared using only Zinc Borate (ZB) as the flame retardant, the percentage was changed and the limit oxygen index of the natural latex vulcanizate film was tested in relation to the amount of zinc borate in the flame retardant, the results were as follows:
zinc borate content
Limiting oxygen index
0
20％
10％
24％
20％
27％
30％
32％
40％
36％
50％
30％
Therefore, when the zinc borate BZ is used as a flame retardant and the content of the zinc borate BZ in the finished rubber is about 30-40%, the limited oxygen index of the rubber is highest and the flame retardant property is also best.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.