TWI481629B - Method for nitrile butadiene rubber latex production and articles made by using the nitrile butadiene rubber latex - Google Patents

Description

Method for preparing carboxylated nitrile latex and articles made thereof using the carboxylated nitrile latex

The invention relates to a preparation method of a latex, in particular to a preparation method of a nitrile latex.

Nitrile latex (NBR) is a latex obtained by copolymerizing monomers such as butadiene and acrylonitrile. Latex gloves made of nitrile latex are widely used in industrial and people's livelihood because of their good oil and chemical resistance. In order to improve the film formation, chemical resistance and mechanical properties of the nitrile latex itself and its application fields, a strategy for adding butadiene by adding a third and a fourth monomer such as a carboxyl group and an ester group has recently been developed. - Modification of acrylonitrile polymer. Carboxy-butyronitrile latex (XNBR) has also gradually replaced the market as a mainstream product due to its better durability.

The preparation of the carboxylated nitrile latex mainly comprises emulsion polymerization, and the reaction raw materials can be divided into three major categories: reaction monomers, emulsifiers and initiators. The reactive monomer is still dominated by butadiene and acrylonitrile, and is combined with other functional monomers. The aforementioned functional single system is used to enhance the properties of the latex (such as chemical resistance, tensile strength, and tensile strength). The aforementioned functional monomers include unsaturated carboxylic acids (acrylic acid, methacrylic acid, or maleic acid), and/or unsaturated carboxylic acid esters (butyl acrylate, or methyl methacrylate and derivatives thereof).

Depending on the initiator system selected, the preparation of carboxylated nitrile latex in the field can be divided into high temperature polymerization (persulfate) and low temperature polymerization (oxidation-reduction system). The high-temperature polymerization method has a relatively fast reaction rate, but also causes a disadvantage that it is difficult to control the stability of the reaction. Therefore, under the double consideration of the stability of the reaction and the characteristics of the latex after synthesis, the low temperature polymerization method is more Selected in the domain. However, the disadvantages of slow reaction rate and low conversion rate of the low-temperature polymerization method are still urgently to be further overcome.

In addition, inorganic auxiliaries such as sulfur, zinc oxide, accelerators, and antioxidants are added to the preparation of the conventional carboxylated nitrile latex to enhance its mechanical properties. These inorganic auxiliaries will inevitably cause precipitation of the latex solution, which may cause difficulties in the operation of the glove production machine and the quality of the finished glove. Moreover, the addition of sulfur as a crosslinking agent requires a aging time of about 24 to 48 hours, which not only prolongs the production time, but also causes the user to have allergies or other health concerns.

In summary, the preparation method of the conventional carboxylated nitrile latex still has the disadvantages that need to be overcome. In view of the increasing use of latex materials, there is an urgent need for a more suitable method for preparing carboxylated nitrile latex.

Accordingly, it is an object of the present invention to provide a method for preparing a carboxylated nitrile latex which mainly employs a low temperature polymerization reaction but which has an excellent conversion ratio.

Another object of the present invention is to provide a method for preparing a carboxylated nitrile latex and a latex product obtained by the method, wherein the method does not require the addition of a sulfur crosslinking agent, thereby reducing health and environmental concerns and shortening the process. advantage.

In order to achieve the above object, the present invention provides a method for preparing a carboxylated nitrile latex, comprising the steps of: a) obtaining a mixture comprising butadiene, acrylonitrile, a functional monomer, an emulsifier, an initiator, and a solvent; b) reacting the above mixture under the following conditions: a pressure of 3.5 to 8.0 Kgf/cm ² and a temperature of 10 to 25 ° C; c) reacting the aforementioned mixture after the reaction of the aforementioned step b in the following conditions; : a pressure of 4.5 to 8.0 Kgf/cm ² and a temperature of 35 to 45 ° C; d) reacting the aforementioned mixture after the reaction of the aforementioned step c in the following conditions: a pressure of 4.5 to 8.0 Kgf/cm ² , and 45 And a temperature of 55 to 45; and e) adding a terminator, and reacting the mixture after the reaction of the aforementioned step d in the following conditions: a pressure of -0.9 to 0.1 Kgf/cm ² , and a temperature of 35 to 45 ° C, That is, the aforementioned carboxylated nitrile latex is obtained; wherein the aforementioned functional monomer contains an unsaturated carboxylic acid.

Preferably, the aforementioned mixture in the aforementioned step a comprises: 20.0 to 25.0 parts by weight of butadiene; 10.0 to 15.0 parts by weight of acrylonitrile; 2.0 to 5.0 parts by weight of unsaturated carboxylic acid; and 0.5 to 2.0 parts by weight Starting agent; 1.0 to 2.5 parts by weight of an emulsifier; and 35.0 to 45.0 parts by weight of a solvent.

Preferably, the aforementioned functional monomer further comprises: 0.1 to 3.0 parts by weight of an unsaturated carboxylic acid ester.

Preferably, the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 0.5 parts by weight of a pH buffer.

Preferably, the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 0.5 part by weight of a chain transfer agent.

Preferably, the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 1.0 part by weight of a structural reinforcing agent.

Preferably, the aforementioned unsaturated carboxylic acid is: methacrylic acid, acrylic acid, maleic acid, or a combination thereof.

Preferably, the aforementioned initiator is an oxidizing initiator. Preferably, the aforementioned oxidizing initiator is an inorganic peroxide. Preferably, the aforementioned inorganic peroxide is: sodium persulfate, potassium persulfate, ammonium persulfate, or a combination thereof.

Preferably, the aforementioned emulsifier is: sodium lauryl sulfate, sodium dodecylbenzenesulfonate, oxiranol lauryl alcohol, polyoxyethylene alkyl ether, or a combination thereof.

Preferably, the aforementioned solvent is: water, isopropyl alcohol, or a combination thereof.

Preferably, the aforementioned unsaturated carboxylic acid ester is: butyl acrylate, butyl methacrylate, isobutyl acrylate, octyl acrylate, octyl methacrylate, or a combination thereof.

Preferably, the aforementioned pH buffering agent is: carbonate, phosphate, pyrophosphate, or a combination thereof.

Preferably, the aforementioned chain transfer agent is: tert-dodecyl mercaptan, n-dodecyl mercaptan, or a combination thereof.

Preferably, the aforementioned structural enhancer is: a triazine-based nitrogen-containing heterocyclic compound, a trifunctional aziridine compound, or a combination thereof.

Preferably, the foregoing method does not comprise a sulfur crosslinker.

Preferably, the mixture is prepared by mixing the acrylonitrile, the functional monomer, the emulsifier, and the solvent into a premix, and adding the butadiene and the initiator to the premix. To form the aforementioned mixture.

Preferably, the aforementioned step b is carried out for 7.0 to 15.0 hours.

Preferably, the aforementioned step c is carried out for 2.0 to 6.0 hours.

Preferably, the aforementioned step d is carried out for 4.5 to 8.5 hours.

Preferably, after the completion of the foregoing step b, the temperature is raised to 35 to 45 ° C within 30 minutes to carry out the aforementioned step c.

Preferably, after the completion of the foregoing step c, the temperature is raised to 45 to 55 ° C within 30 minutes to carry out the aforementioned step d.

Preferably, after the completion of the step b, an emulsifier and a reducing agent are added, and then the above step c is performed.

Preferably, after the completion of the foregoing step c, after adding an emulsifier and a reducing agent, the foregoing step d is performed.

Preferably, the emulsifier is sodium lauryl sulfate, sodium dodecylbenzene sulfonate, oxiranol lauryl alcohol, polyoxyethylene alkyl ether, or combination.

Preferably, the reducing agent is sodium bisulfite, sodium hydrogen sulfite, ferrous sulfate, or a combination thereof.

Preferably, the aforementioned terminator of the above step e is added in an amount of 50 to 400 ppm.

Preferably, the foregoing terminator is sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dimethyldithiocarbamate, ammonium dimethyldithiocarbamate, p-phenylene Phenol, diethylhydroxylamine, or a combination thereof.

Preferably, the aforementioned step e further comprises adjusting the pH to 7.5 to 8.5.

Preferably, the aforementioned step e further comprises adding a deodorizer. Preferably, the aforementioned deodorant is an acrylate latex deodorant.

Preferably, the aforementioned step e further comprises adding an antifoaming agent. Preferably, the aforementioned antifoaming agent is an organic cerium polymer, mineral oil, or a combination thereof.

Preferably, after the step e, further comprising a step f, the step f is carried out under the pressure of -3.0 to -5.0 Kgf / cm ² to: introduce nitrogen; perform pumping, and stir through the aforementioned step e reaction After the aforementioned mixture; stop introducing nitrogen; stop pumping; and perform a filtration step.

Preferably, the foregoing method is carried out at a temperature of from 10 to 55 °C.

Preferably, the conversion of the aforementioned method is at least 90%. More preferably, the aforementioned conversion rate is at least 96%.

The invention further provides a carboxylated nitrile latex product prepared by using a carboxylated nitrile latex prepared by the method as described above, having a tensile strength of 20 to 25 MPa and an elongation of 550 to 700%. .

Preferably, the aforementioned carboxylated nitrile latex product is a glove or a garment.

In summary, the preparation method of the carboxylated nitrile latex of the present invention is adopted. The method of the present invention provides a high-temperature stability of low-temperature polymerization and a high conversion rate of high-temperature polymerization by performing one-time feeding and gradient heating. Accordingly, not only latex products excellent in tensile strength and elongation can be prepared, but the method can overcome the disadvantages of low conversion rate and time spent in the conventional process.

In the preparation method of the carboxylated nitrile latex, the reaction conditions (temperature and pressure), the feeding mode and the degassing step are important factors affecting the quality of the obtained carboxylated nitrile latex. Accordingly, the main concept of the method for preparing a carboxylated nitrile latex of the present invention is "one-time feeding" and "gradient heating", and has the advantages of high stability of conventional low-temperature polymerization and high conversion rate of high-temperature polymerization. Moreover, the method of the invention does not require the addition of a sulfur crosslinking agent, which is beneficial to the environment and the health of the user. In addition, the degassing step in the preparation process of the present invention helps to maintain the stability of the carboxylated nitrile latex and prolong the service life of the tank during the process.

The term "disposable feed" as used in the present invention means that all the desired butadiene, acrylonitrile, functional monomer, emulsifier, solvent and initiator are completed before the emulsion polymerization (before the gradient temperature is raised). mixing. In a preferred embodiment of the present invention, at least one additional emulsifier and reducing agent may be added to the subsequent emulsion polymerization to make the emulsion polymerization more complete and to increase the conversion of the process of the present invention.

The term "gradient temperature rise" as used in the present invention means that the reaction raw materials are reacted discontinuously in different temperature classes in the overall process. This method is to carry out an emulsion polymerization reaction in a low temperature environment to improve the stability, and then, an emulsion polymerization reaction is carried out in a high temperature environment to increase the conversion rate. The aforementioned low temperature environment and the aforementioned high temperature environment are defined according to the low temperature polymerization and high temperature polymerization which are conventionally known in the art. More specifically, the foregoing The low temperature environment means between 10 and 25 ° C; and the aforementioned high temperature environment means between 45 and 55 ° C.

Referring to the first figure, the preparation method of the carboxylated nitrile latex of the present invention comprises at least the reactants required for mixing in the step a (101), followed by the first stage polymerization of the step b (102) 7.0 to 15.0. Hour, the second stage polymerization of step c (103) is 2.0 to 6.0 hours, and the third stage polymerization of step d (104) is 4.5 to 8.5 hours, and then a terminator is added to carry out step e (105) to terminate the reaction. Proceed to step f (106) for subsequent remaining monomer treatment and filtration treatment. A replenishing liquid may optionally be added between the aforementioned step b (102) and the aforementioned step c (103), and/or between the aforementioned step c (103) and the aforementioned step d (104) to make the reaction more complete. The aforementioned replenishing liquid may contain an emulsifier, a reducing agent, or a combination thereof.

The steps of the method of the invention are detailed below:

a) preparing a reaction raw material mixture

The reaction raw materials are introduced into a reaction tank. The aforementioned reaction raw material contains 20.0 to 25.0 parts by weight of butadiene; 10.0 to 15.0 parts by weight of acrylonitrile; 2.0 to 5.0 parts by weight of unsaturated carboxylic acid; 0.5 to 2.0 parts by weight of the initiator; and 1.0 to 2.5 parts by weight. An emulsifier; and 35.0 to 45.0 parts by weight of a solvent.

In a possible embodiment, the aforementioned reaction raw material further comprises 0.1 to 3.0 parts by weight of an unsaturated carboxylic acid ester, 0.1 to 0.5 part by weight of a pH buffering agent, 0.1 to 0.5 part by weight of a chain transfer agent, and/or 0.1 to 1.0 part by weight of a structural enhancer. The aforementioned unsaturated carboxylic acid and/or the aforementioned unsaturated carboxylic acid ester are functional monomers used in the process of the present invention.

In a preferred embodiment, the foregoing mixture is prepared by first adding the aforementioned acrylonitrile, the aforementioned functional monomer (including the aforementioned unsaturated carboxylic acid, and the foregoing The unsaturated carboxylic acid ester), the emulsifier, and the solvent are mixed into a premix, and the butadiene and the starter are added to the premix to form the mixture. In this preferred embodiment, all of the desired reactants are still mixed prior to the emulsion polymerization (before the gradient is ramped up) and thus still conform to the "disposable feed" characteristics of the present invention.

The above-mentioned butadiene and the aforementioned acrylonitrile are the main reactants in the process of the present invention, and the aforementioned functional monomers (including the aforementioned unsaturated carboxylic acid and the aforementioned unsaturated carboxylic acid ester) are used for modifying the carboxylated nitrile to be obtained. Latex to enhance its resistance to chemical resistance, tensile strength, and tensile strength. The aforementioned unsaturated carboxylic acids include, but are not limited to, methacrylic acid, acrylic acid, maleic acid, or a combination thereof. The aforementioned unsaturated carboxylic acid esters include, but are not limited to, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, or a combination thereof.

The emulsifier is, for example, an anionic emulsifier and/or a nonionic emulsifier. Examples of the aforementioned emulsifier include, but are not limited to, sodium alkylsulfonate, sodium alkyl sulfate, fatty alcohol polyoxyethylene ether, or potassium oleate. The emulsifier has the effect of promoting the smoothness of the reaction, and is sensitive to the coagulant, so that the latex solution is easily emulsified and rapidly formed into a film, which contributes to the preparation of the subsequent latex product.

Preferably, the aforementioned solvent is: water, isopropyl alcohol, or a combination thereof. Preferably, the aforementioned water is deionized water. Preferably, the aforementioned initiator is an oxidizing initiator, such as an inorganic peroxide. The aforementioned inorganic peroxides include, but are not limited to, sodium persulfate, potassium persulfate, ammonium persulfate, or combinations thereof.

The aforementioned pH buffering agent is used to stabilize the overall reaction, including, but not limited to, carbonates, phosphates, pyrophosphates, or combinations thereof. The aforementioned chain transfer agent is used to control the molecular weight of the obtained carboxylated nitrile latex so as to fall within the desired molecular weight range. The aforementioned chain transfer agent package Including, but not limited to, tert-dodecyl mercaptan, n-dodecyl mercaptan or a combination thereof.

The foregoing structural enhancers include, but are not limited to, triazine nitrogen-containing heterocyclic compounds, trifunctional aziridine compounds, or combinations thereof. For example, the aforementioned structural enhancer is: melamine, melamine, or a combination thereof.

Feasibly, the aforementioned triazine-containing nitrogen-containing heterocyclic compound has the following structural formula 1: Wherein the aforementioned R ₁ and R ₂ are each H, CH ₂ OH, or CH ₂ OCH ₃ .

Feasibly, the aforementioned trifunctional aziridine compound has the following structural formula 2: Wherein R ₃ is CH ₃ or OH; and R ₄ is CH ₃ or H.

b) the first stage emulsion polymerization

In the step b, the mixture is reacted by a pressure valve and a temperature control device under the following conditions: a pressure of 3.5 to 8.0 Kgf/cm ² and a temperature of 10 to 25 °C. In a preferred embodiment, the mixture is reacted in the first stage for 7.0 to 15.0 hours, and thereafter the temperature and pressure are adjusted from the temperature and pressure required for the subsequent step c in 30 minutes.

In a preferred embodiment, after the mixture is reacted in the first stage for 7.0 to 15.0 hours, a first replenishing liquid is further added to the mixture to increase the conversion rate and improve the conversion rate. The aforementioned first replenishing liquid contains the aforementioned emulsifier and a reducing agent. The aforementioned reducing agents include, but are not limited to, sodium bisulfite, sodium sulfite, sodium hydrogen sulfite, or a combination thereof.

c) second stage emulsion polymerization

In the step c, the mixture is reacted by a pressure valve and a temperature control device under the following conditions: a pressure of 4.5 to 8.0 Kgf/cm ² and a temperature of 35 to 45 °C. In a preferred embodiment, the mixture is reacted in the second stage for 2.0 to 6.0 hours, and thereafter the temperature and pressure are adjusted from the temperature and pressure required for the subsequent step d within 30 minutes.

In a preferred embodiment, after the mixture is reacted in the second stage for 2.0 to 6.0 hours, a second replenishing liquid is further added to the mixture to increase the conversion rate more completely and increase the conversion rate. The aforementioned second replenishing liquid comprises the aforementioned emulsifier and a reducing agent. The aforementioned reducing agents include, but are not limited to, sodium bisulfite, sodium sulfite, sodium hydrogen sulfite, or a combination thereof.

d) third stage emulsion polymerization

In the step d, the mixture is reacted by a pressure valve and a temperature control device under the following conditions: a pressure of 4.5 to 8.0 Kgf/cm ² and a temperature of 45 to 55 °C. In a preferred embodiment, after the mixture is reacted in the third stage for 4.5 to 8.5 hours, the stirring speed is lowered and pressure relief is started.

e) stop the reaction

The pressure was adjusted to -0.9 to 0.1 Kgf/cm ² by a pressure valve and a temperature control device, and the temperature was adjusted to 35 to 45 °C. The terminator is then added to maintain the reaction for 0.25 to 0.5 hours under the aforementioned pressure and temperature conditions. Then, after the dissociation agent and/or antifoaming agent is added, the reactants are transferred to an evacuation tank for a subsequent degassing step (step f).

In one possible embodiment, the foregoing terminator is added in an amount of 50 to 400 ppm. The foregoing terminators include, but are not limited to, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dimethyldithiocarbamate, ammonium dimethyldithiocarbamate, p-benzene. Diphenol, diethylhydroxylamine, or a combination thereof. In a preferred embodiment, the pH of the reaction mixture in the preceding step e is adjusted to 7.5 to 8.5. In a possible embodiment, the pH is adjusted by means of an lye. The aforementioned alkali solution includes, but is not limited to, ammonia water, an aqueous potassium hydroxide solution, or a combination thereof. In a possible embodiment, the aforementioned deodorant is an acrylate latex deodorant. Preferably, the aforementioned deodorant is added in an amount of from 100 to 1000 ppm. In a possible embodiment, the aforementioned antifoaming agent is an organic cerium polymer, mineral oil or a combination thereof. Preferably, the aforementioned antifoaming agent is added in an amount of from 100 to 1000 ppm.

f) Degassing step

The pressure in the suction tank is adjusted by the pressure valve to be -3.0 to -5.0 Kgf/cm ² , and nitrogen is introduced to react for 3 to 5 hours; wherein, under continuous pumping, the reactants in the tank are continuously stirred. The reaction is completed. Thereafter, the pumping is stopped, and the temperature is lowered to room temperature by a temperature control device, and then transferred to a filtering device for filtration to obtain the obtained carboxylated nitrile latex. The foregoing filtration steps can be carried out by means well known in the art including, but not limited to, bag filtration, plate filtration, vane filtration, cross flow filtration, membrane filtration, or combinations thereof.

More specifically, referring to the second drawing, the step f of the present invention starts the pumping agitation (201) after the nitrogen gas is introduced into the liquid. After evacuation (201) for 2 to 3 hours, the flow of nitrogen gas was stopped, and suction stirring (202) was continued. After evacuation (202) for 1 to 2 hours, the pumping was stopped, and the reaction product in the tank was passed through a filtering device to carry out a filtration step, and then the obtained carboxylated nitrile latex was obtained.

It should be understood by those of ordinary skill in the art that the foregoing step e has produced a carboxylated nitrile latex, and the foregoing step f is for removing residual monomers in the reaction to increase the purity of the obtained carboxylated nitrile latex. It is common in the art to select whether to perform the aforementioned step f from the visible condition. If the above step f is not desired, the obtained carboxylated nitrile latex can be obtained by a suitable filtration procedure after the above step e.

The carboxylated nitrile latex prepared according to the present invention can be used as a raw material for a latex product. The foregoing articles include, but are not limited to, gloves or apparel. Taking the preparation of the carboxylated nitrile latex glove as an example, it can be carried out by a method known in the art, simply: 100.0 parts by weight of carboxylated nitrile latex, 0.6 to 1.0 part by weight of zinc oxide, 1.5 to 2.0 weight. The portion of titanium dioxide, 35.0 to 45.0 parts by weight of deionized water and 0.2 to 0.3 parts by weight of potassium hydroxide are mixed and stirred in a tank for 2 to 4 hours. Next, the resulting mixture was uniformly adhered to a hand mold previously immersed in a coagulant, and surface-treated simultaneously. Then, the hand that is stained with the aforementioned mixed product The mold was baked at 115 to 125 ° C for 15 to 25 minutes. Finally, a carboxylated nitrile latex glove is prepared after other desired subsequent treatments.

The following examples are intended to further understand the advantages of the present invention and are not intended to limit the scope of the invention.

Example 1: Preparation of carboxylated nitrile latex by the method of the present invention [incoming]

43.0 parts by weight of deionized water, a total of 1.0 part by weight of sodium lauryl sulfate, sodium dodecylbenzenesulfonate and a mixture of ethylene oxide lauryl alcohol (emulsifier), 0.1 parts by weight of carbonate (pH buffer), 2.0 parts by weight of methacrylic acid, 2.0 parts by weight of butyl acrylate, 0.2 parts by weight of t-dodecyl mercaptan (chain transfer agent), and 12.0 parts by weight of acrylonitrile were added to the tank. After confirming that the tank body has been sealed, it is mixed and stirred. Then, after completely replacing the air in the tank and the mixed solution with nitrogen, the vacuum was stopped, and 22.0 parts by weight of butadiene was injected into the tank, and finally 0.2 part by weight of the initiator was injected.

[Reaction Control and Replenishment Addition]

The pressure in the tank was adjusted to 4.0 Kgf/cm ² with nitrogen at 25 ° C and the first-stage polymerization was started. After the first-stage polymerization reaction is carried out for 9.0 hours, the first replenishing liquid is added (a total of 0.05 parts by weight of sodium lauryl sulfate, sodium dodecylbenzenesulfonate and ethoxylated lauryl alcohol mixture, and 0.1 parts by weight of sodium bisulfite). Next, the temperature was raised to 40 ° C in 30 minutes by gradient heating (the pressure in the tank was adjusted to 3.9 Kgf / cm ² ) to carry out the second-stage polymerization.

After the second-stage polymerization reaction is carried out for 4.5 hours, a second replenishing solution is added (a total of 0.05 parts by weight of sodium lauryl sulfate, sodium dodecylbenzenesulfonate and an oxirane lauryl alcohol mixture, and 0.1 part by weight of sodium bisulfite) was further raised to 50 ° C in 30 minutes by a gradient heating method (the pressure in the tank was adjusted to 5.0 Kgf/cm ² ) to carry out the third-stage reaction.

After the third-stage polymerization reaction was carried out for 8.0 hours, after the conversion rate of the reactants was found to be 96% or more, the stirring speed was decreased and pressure relief was started. When the pressure in the tank was 0 Kgf/cm ² , the inside of the reaction tank was The temperature was lowered to 45 ° C and a terminator was added. Among them, the pH value is adjusted to 7.5~8.5 with alkali solution, and after the reactant is held in the temperature stirring tank for 30 minutes, the deodorant and the defoaming agent are added, and the reactant is transferred into the suction tank for subsequent vacuum. Pumping degassing step.

[Residual monomer removal and post-treatment (degassing step)]

After adjusting the degree of vacuum to -0.3 Kgf/cm ² in an evacuation tank, the reaction was carried out for 2.0 hours by subsurface nitrogen gas to remove residual monomers. Finally, after the temperature was lowered to room temperature, a filtration step was carried out to obtain a carboxylated nitrile latex of the present example.

Example 2: Preparation of carboxylated nitrile latex by the method of the invention

A carboxylated nitrile latex was prepared by the method described in Example 1, except that the amount of methacrylic acid used was changed to 3.0 parts by weight, and the amount of butyl acrylate was changed to 1.0 part by weight, while sodium lauryl sulfate and ten were used. The amount of the sodium dialkylbenzenesulfonate and the oxirane lauryl alcohol mixture was changed to 1.1 parts by weight.

Example 3: Preparation of carboxylated nitrile latex by the method of the invention

Preparing a carboxylated nitrile latex by the method described in Example 1, except that The amount of methacrylic acid used was changed to 3.0 parts by weight, and the amount of butyl acrylate was changed to 1.0 part by weight, and sodium lauryl sulfate, sodium dodecylbenzenesulfonate and ethylene oxide lauryl alcohol were mixed. The amount of the liquid used was changed to 1.1 parts by weight. Further, the time of the first-stage polymerization reaction was changed to 13.0 hours, the time of the second-stage polymerization reaction was changed to 3.0 hours, and the time of the third-stage polymerization reaction was changed to 6.0 hours.

Example 4: Preparation of carboxylated nitrile latex by the method of the invention

A carboxylated nitrile latex was prepared by the method described in Example 1, except that the amount of methacrylic acid used was changed to 3.0 parts by weight, and the amount of butyl acrylate was changed to 1.0 part by weight, while sodium lauryl sulfate and ten were used. The amount of the sodium dialkylbenzenesulfonate and the oxirane lauryl alcohol mixture was changed to 1.1 parts by weight. Further, the time of the first-stage polymerization reaction was changed to 13.0 hours and the temperature was changed to 15 ° C, the time of the second-stage polymerization reaction was changed to 3.0 hours, and the time of the third-stage polymerization reaction was changed to 6.0 hours.

Example 5: Preparation of carboxylated nitrile latex by the method of the invention

A carboxylated nitrile latex was prepared by the method described in Example 1, except that the amount of methacrylic acid used was changed to 3.0 parts by weight, and the amount of butyl acrylate was changed to 1.0 part by weight, while sodium lauryl sulfate and ten were used. The amount of the sodium dialkylbenzenesulfonate and the oxirane lauryl alcohol mixture was changed to 1.1 parts by weight. Further, the time of the first-stage polymerization reaction was changed to 13.0 hours and the temperature was changed to 15.0 ° C, the time of the second-stage polymerization reaction was changed to 3.0 hours, and the time of the third-stage polymerization reaction was changed to 6.0 hours. Further, after the above degassing step, 0.2 part by weight of melamine was further added.

Example 6: Physical property detection

In the embodiment, the first embodiment to the fifth embodiment will be detected. The properties of the obtained carboxylated nitrile latex include: conversion, solid content, viscosity, pH, particle size, acrylonitrile content, and residual acrylonitrile. In addition, the carboxylated nitrile latex latex prepared by using the above-mentioned Examples 1 to 5 as raw materials is prepared separately from the latex prepared by the commercially available carboxylated nitrile latex containing sulfur crosslinking agent. Example 1) Compare with each other.

The properties of the carboxylated nitrile latex of the present invention are listed in Table 1. Further, the carboxylated nitrile latex latex of the present invention and a commercially available carboxylated nitrile latex latex glove containing a sulfur crosslinking agent are listed in Table 2.

It can be seen from the data listed in the above Table 1 that the method of the present invention has excellent conversion ratio. Further, from the data in the above Table 2, the carboxylated nitrile latex latex of the present invention has good tensile strength and elongation. Accordingly, the method of the present invention does not require the use of a sulfur cross-linking agent, and has the advantages of saving time and benefiting the environment and the health of the user, and the obtained carboxylated nitrile latex product is more resistant than the commercially available carboxylated nitrile latex product. Tensile strength and elongation. Thus, the process of the invention is particularly suitable for use in the preparation of carboxylated nitrile latex articles, for example, industrial grade, medical grade, or electronic grade disposable gloves or apparel.

It will be apparent to those skilled in the art that various changes can be made in accordance with the embodiments of the present invention without departing from the spirit of the invention. Therefore, it is to be understood that the invention is not limited by the scope of the invention, and is intended to cover the modifications of the spirit and scope of the invention.

101‧‧‧Step a

102‧‧‧Step b

103‧‧‧Step c

104‧‧‧Step d

105‧‧‧Step e

106‧‧‧Step f

201‧‧‧Aspirator

202‧‧‧Pumping and stirring

The first figure is a flow chart illustrating the method of the invention.

The second figure is a flow chart showing the step f of the method of the present invention.

101‧‧‧Step a

102‧‧‧Step b

103‧‧‧Step c

104‧‧‧Step d

105‧‧‧Step e

106‧‧‧Step f

Claims (40)

A method for preparing a carboxylated nitrile latex, comprising the steps of: a) obtaining a mixture comprising butadiene, acrylonitrile, a functional monomer, an emulsifier, a starter, and a solvent; b) allowing the aforementioned mixture to The reaction is carried out under the following conditions: a pressure of 3.5 to 8.0 Kgf/cm ² and a temperature of 10 to 25 ° C; c) reacting the aforementioned mixture after the reaction of the aforementioned step b in the following conditions: 4.5 to 8.0 Kgf/cm ² The pressure and the temperature of 35 to 45 ° C; d) reacting the mixture after the reaction of the aforementioned step c in the following conditions: a pressure of 4.5 to 8.0 Kgf/cm ² , and a temperature of 45 to 55 ° C; The terminating agent is added, and the above mixture after the reaction of the above step d is subjected to a reaction under the following conditions: a pressure of -0.9 to 0.10 Kgf/cm ² and a temperature of 35 to 45 ° C to obtain the aforementioned carboxylated nitrile latex. Wherein the aforementioned functional monomer comprises an unsaturated carboxylic acid. The method of claim 1, wherein the aforementioned mixture in the aforementioned step a comprises: 20.0 to 25.0 parts by weight of butadiene; 10.0 to 15.0 parts by weight of acrylonitrile; and 2.0 to 5.0 parts by weight of unsaturated carboxylic acid. Acid; 0.5 to 2.0 parts by weight of the initiator; 1.0 to 2.5 parts by weight of the emulsifier; and 35.0 to 45.0 parts by weight of the solvent. The method of claim 2, wherein the aforementioned functional monomer further comprises: 0.1 to 3.0 parts by weight of an unsaturated carboxylic acid ester. The method of claim 2, wherein the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 0.5 part by weight of a pH buffer. The method of claim 2, wherein the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 0.5 part by weight of a chain transfer agent. The method of claim 2, wherein the aforementioned mixture in the aforementioned step a further comprises: 0.1 to 1.0 part by weight of a structure enhancer. The method of any one of claims 1-6, wherein the aforementioned unsaturated carboxylic acid is: methacrylic acid, acrylic acid, maleic acid, or a combination thereof. The method of any one of claims 1-6, wherein the initiator is an oxidizing initiator. The method of claim 8, wherein the oxidizing initiator is an inorganic peroxide. The method of claim 9, wherein the inorganic peroxide is: sodium persulfate, potassium persulfate, ammonium persulfate, or a combination thereof. The method according to any one of claims 1 to 6, wherein the emulsifier is: sodium lauryl sulfate, sodium dodecylbenzenesulfonate, oxiranol lauryl alcohol, polyoxygen A vinyl alkyl ether, or a combination thereof. The method of any one of claims 1-6, wherein The aforementioned solvent is: water, isopropyl alcohol, or a combination thereof. The method of claim 3, wherein the unsaturated carboxylic acid ester is: butyl acrylate, butyl methacrylate, isobutyl acrylate, octyl acrylate, octyl methacrylate, or a combination thereof . The method of claim 4, wherein the pH buffering agent is: carbonate, phosphate, pyrophosphate, or a combination thereof. The method of claim 5, wherein the chain transfer agent is: tert-dodecyl mercaptan, n-dodecyl mercaptan, or a combination thereof. The method of claim 6, wherein the structural enhancer is: a triazine-based nitrogen-containing heterocyclic compound, a trifunctional aziridine compound, or a combination thereof. The method of claim 1, which does not comprise a sulfur crosslinker. The method of claim 1, wherein the mixture is prepared by mixing the acrylonitrile, the functional monomer, the emulsifier, and the solvent into a premix, and then adding the butadiene and The foregoing initiator is added to the aforementioned premix to form the aforementioned mixture. The method of claim 1, wherein the aforementioned step b is carried out for 7.0 to 15.0 hours. The method of claim 1, wherein the aforementioned step c is performed for 2.0 to 6.0 hours. The method of claim 1, wherein the aforementioned step d is performed for 4.5 to 8.5 hours. The method of claim 19, wherein the foregoing step b After completion, the temperature was raised to 35 to 45 ° C in 30 minutes to carry out the aforementioned step c. The method of claim 20, wherein after the step c is completed, the temperature is raised to 45 to 55 ° C within 30 minutes to perform the aforementioned step d. The method of claim 19, wherein after the step b is completed, an emulsifier and a reducing agent are added, and then the step c is performed. The method of claim 20, wherein after the step c is completed, an emulsifier and a reducing agent are added, and then the step d is performed. The method of claim 24, wherein the emulsifier is sodium lauryl sulfate, sodium dodecylbenzenesulfonate, oxiranol lauryl alcohol, polyoxyethylene alkyl ether, Or a combination thereof. The method of claim 24, wherein the reducing agent is sodium bisulfite, sodium hydrogen sulfite, ferrous sulfate, or a combination thereof. The method of claim 1, wherein the foregoing terminator of the step e is added in an amount of 50 to 400 ppm. The method of claim 28, wherein the terminating agent is sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dimethyldithiocarbamate, dimethyldi Ammonium thiocarbamate, hydroquinone, diethylhydroxylamine, or a combination thereof. The method of claim 1, wherein the step e further comprises adjusting the pH to 7.5 to 8.5. The method of claim 1, wherein the step e further comprises adding a deodorant. The method of claim 31, wherein the deodorant is an acrylate latex deodorant. The method of claim 1, wherein the step e further comprises adding an antifoaming agent. The method of claim 33, wherein the antifoaming agent is an organic cerium polymer, mineral oil, or a combination thereof. The method of claim 1, further comprising a step f after the step e, wherein the step f is performed at a pressure of -3.0 to -5.0 Kgf/cm ² to introduce nitrogen gas; Pumping, stirring the aforementioned mixture after the reaction of the above step e; stopping the introduction of nitrogen; stopping the pumping; and performing the filtration step. The method of claim 1, wherein the method is carried out at a temperature of from 10 to 55 °C. The method described in claim 1 has a conversion rate of at least 90%. The method of claim 37, the conversion rate is at least 96%. A carboxylated nitrile latex product, which is as claimed in claim 1 The carboxylated nitrile latex obtained by the method described in the present invention is prepared by using a raw material having a tensile strength of 20 to 25 MPa and an elongation of 550 to 700%. A carboxylated nitrile latex product as described in claim 39, which is a glove or a garment.