WO2018105891A1 - Carboxylic acid-modified nitrile-based copolymer latex and latex composition for dip molding comprising same - Google Patents

Abstract

The present invention relates to a carboxylic acid-modified nitrile-based copolymer latex, a method for producing the same, a latex composition for dip molding comprising the same, and a molded article produced therefrom. More specifically, the present invention relates to a carboxylic acid-modified nitrile-based copolymer latex which is produced such that an anionic compound is present on a large amount on the surface of latex particles, thereby ensuring physical properties equal to or greater than those using sulfur and a vulcanization accelerator or a crosslinking agent such as zinc oxide, etc. without using the same, a method for producing the same, a latex composition for dip molding comprising the same, and a molded article produced therefrom.

Description

Carbonic acid-modified nitrile copolymer latex and latex composition for dip molding comprising the same

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0167341 of December 9, 2016 and Korean Patent Application No. 10-2017-0132671 of October 12, 2017, All disclosures are included as part of this specification.

The present invention relates to a carboxylic acid-modified nitrile copolymer latex capable of crosslinking by bonding an anion with a polyvalent metal ion and a latex composition for dip molding comprising the same.

Rubber gloves are increasingly being used with increasing awareness of personal safety in a wide range of fields, including food, electronics and medical. Allergy symptoms such as pain and skin rash have been known to occur only by natural rubber gloves made by dip molding natural rubber, but recently, allergens can be caused by sulfur-crosslinked gloves made by dip molding synthetic latex. have. This is because vulcanization accelerators (thiuram-based, carbamate-based) used to promote sulfur crosslinking cause symptoms such as contact dermatitis with the fourth type delayed allergy. In addition, when making gloves using sulfur and a vulcanization accelerator, a curing process is required at a high temperature. Hydrogen sulfide, sulfur dioxide, and other low molecular weight mercaptans threaten worker health and cause an unpleasant odor.

Zinc oxide, which is used for the crosslinking of synthetic latex together with sulfur and vulcanization accelerator, forms an ionic bond with carboxylic acid of the synthetic latex, and the strength is weakened due to the nature of the ionic bond. The food industry often handles acidic solutions such as vinegar acid when gloves are used. At this time, zinc ions may be eluted by the acid solution. Rubber gloves used in the food industry regulate the amount of zinc ions eluted by acid solutions.

Various attempts have been made to make rubber gloves without using them to prevent side effects caused by sulfur and vulcanization accelerators.

However, most of these attempts use zinc oxide, and as mentioned above, when working with acid solutions, the metal bonds between zinc ions and carboxylic acids are weakened, reducing the strength and durability of the gloves. In addition, there is a possibility that zinc ions are eluted and transferred to working materials. In this case it is difficult to have similar durability and chemical resistance compared to gloves made by sulfur and vulcanization accelerators.

The main components of human sweat are ammonia, urea, and citric acid. The sweat component can weaken the metal bond between carboxylic acid and zinc ions. In addition, ionic bonds of zinc ions that are not covalent bonds due to sulfur crosslinking are easily broken in polar solvents, thereby degrading the chemical resistance of gloves.

(Patent Document 1) Republic of Korea Patent Publication No. 2014-0053859 (2014.05.08), highly saturated nitrile rubber composition and rubber crosslinked product

The present invention in the polymerization of rubber latex to solve the above problems, induce crosslinking by ionic bonding of anions and polyvalent metal cations, wherein the anion is present on the surface of the latex particles in order to increase the ionic binding force The present invention was completed by confirming that physical properties equivalent to those using these can be secured without using a conventional sulfur and a vulcanization accelerator or a crosslinking agent such as zinc oxide.

Accordingly, it is an object of the present invention to provide a carboxylic acid-modified nitrile copolymer latex having a controlled content of anionic compound present on the surface of latex particles and a method for producing the same.

In addition, another object of the present invention is to provide a latex composition for dip molding comprising the carboxylic acid-modified nitrile copolymer latex.

In addition, another object of the present invention is to provide a dip molded article prepared from the latex composition for dip molding, almost no extraction of metal cations, and excellent durability and chemical resistance.

In order to achieve the above object, the present invention is a copolymerized carboxylic acid modified nitrile including conjugated diene monomer, ethylenically unsaturated nitrile monomer, unsaturated carboxylic acid monomer, unsaturated dicarboxylic acid monomer and sulfur oxyanion compound In the copolymer latex,

A carboxylic acid-modified nitrile copolymer latex is characterized in that at least 80% by weight of the total content of the unsaturated carboxylic acid monomer, unsaturated dicarboxylic acid monomer and sulfur oxyanion compound is copolymerized on the surface of the latex particles. to provide.

The present invention also provides a carboxylic acid-modified nitrile copolymer through a polymerization step including a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound. Make latex,

At 10 to 50% of the polymerization conversion rate in the polymerization step, the copolymerization is carried out by additionally administering any one of an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound. Provided is a method for producing the acid-modified nitrile copolymer latex.

In addition, the present invention is a carboxylic acid-modified nitrile copolymer latex; And it provides a latex composition for dip molding comprising a polyvalent metal cation compound.

In addition, the present invention provides a dip molded product, characterized in that the dip molded by the dip molding latex composition.

The carboxylic acid-modified nitrile copolymer latex according to the present invention can secure physical properties equivalent to those of crosslinking by sulfur and vulcanization accelerators or zinc oxide crosslinking agents through ionic bonding between anions and polyvalent metal ions.

In particular, the latex dip molded article has a metal ion of less than 0.1 ppm in an acidic solution, which can be safely used in the food field, and also has excellent durability against various solvents with high durability that is not easily torn off by sweat. It can be secured. In addition, the non-use of sulfur and vulcanization accelerators can solve the problem of skin allergies.

1 is a graph showing the pH change according to the KOH dose.

2 is an analysis spectrum by GC / FID.

Hereinafter, the present invention will be described in more detail to aid in understanding the present invention.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Carboxylic Acid Modified Nitrile Copolymer Latex

The present invention provides a carboxylic acid-modified nitrile copolymer latex, but the anion is present on the surface of the copolymer latex particles, crosslinking is possible through ionic bonds with polyvalent metal cations, causing problems such as conventional allergies The present invention proposes a copolymer latex capable of securing the same or more physical properties without using zinc oxide, which is difficult to dissolve in sulfur and vulcanization accelerators or acidic solutions.

The carboxylic acid-modified nitrile copolymer proposed in the present invention is copolymerized including a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound. .

Among the monomers constituting the copolymer, the unsaturated carboxylic acid monomer and the unsaturated dicarboxylic acid monomer include an anion called a carboxyl group, and the sulfur oxygen anion compound includes an anion such as sulfate or sulfonate. In this respect, the anion referred to herein means that the carboxyl group (COO ⁻ ), the sulfate group (SO ₃ ⁻ ) and the sulfonate group (SO ₄ ^2- ) are added together. In addition, the monomer and compound containing the anion are hereinafter referred to collectively as 'anionic compound'.

In the carboxylic acid-modified nitrile-based copolymer according to the present invention, the anion is generally present randomly throughout the copolymer latex particles by the monomer or sulfur oxygen anion during the copolymerization including the monomers. However, the present invention is characterized in that the anionic compound having the anion is present in a copolymerized form on the surface of the latex particles so that the anion is concentrated on the surface of the copolymer latex particles.

The presence or absence of the anionic compound on the surface of the latex particle can be analyzed by a titration method, acid value measurement, NMR (magnetic resonance analysis), or FT-IR (Fourier-converted ultraviolet spectral analysis). Among these, acid value, NMR, and FT-IR only predict the content of the anionic compound as a whole, and it is not easy to measure the content of the anionic compound present on the surface to be obtained in the present invention.

Specifically, the content of the anionic compound present on the surface of the latex particles is obtained through a method of calculating the amount of KOH consumed to neutralize the anion present in the anionic compound by selective neutralization. Proceed.

First, the copolymer latex is diluted to 10% and then stirred at 90 ° C./2 hours at pH 12 by adding 3% aqueous KOH solution. After cooling the obtained dilution to room temperature, the pH is adjusted to 2 by adding 2% hydrochloric acid aqueous solution and stirred for 90 ℃ / 2 hours. Subsequently, the temperature is lowered to room temperature and then titrated with 3% aqueous KOH solution to calculate the amount of anion bound to the particle surface. In this case, the higher the content of the anion measured by the selective polymerization method, the higher the content of the anion on the surface.

Carboxylic acid-modified nitrile copolymer latex according to the present invention is measured through the calculation of the amount of KOH consumed by the selective neutralization method, 80% by weight or more, preferably 83% by weight or more of the content of the total anionic compound, More preferably 85 to 99.5% by weight is present on the latex particle surface. In the present invention, at least 80% by weight of 100% by weight of the total anionic compound is 'present on the surface' or 'present on the surface' of the copolymer latex particles. It means that at least 80% by weight of the total amount of the anionic compound having anions on the copolymer can be present on the surface. If an anionic compound having an anion for ionic bonding is present inside the particle, even if the pH is increased due to the degree of crosslinking of the copolymer particles, the anionic compound does not bond with the multivalent metal cation. In other words, when the anionic compound is not bound to the copolymer and is present in the serum, the anionic compound does not help to increase the durability and chemical resistance of the dip molded article even if it is combined with a polyvalent metal cation.

More specifically, the content of the surface carboxylic acid present on the surface of the copolymer particles is 5% by weight or more, and the content of the carboxylic acid remaining in the copolymer serum is preferably 0.1% by weight or less.

In order to be present in the form of a copolymerized form of at least 80% by weight of an anionic compound on the surface of the copolymer latex particles as described above, the type and content of each monomer used to prepare the carboxylic acid-modified nitrile copolymer should be limited, Process control is required.

The carboxylic acid-modified nitrile copolymer according to the present invention comprises a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound, followed by a polymerization step. Manufacture.

The conjugated diene monomer is at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and isoprene Of these, 1,3-butadiene is most preferably used.

The conjugated diene monomer is 35 to 80% by weight, preferably 40 to 75% by weight, more preferably 45 to 70% by weight within 100% by weight of the total content of the total monomer constituting the carboxylic acid-modified nitrile copolymer Included as. If the content is less than the above range, the dip molded product becomes hard and the wear feeling worsens. On the contrary, if the content exceeds the above range, the oil resistance of the dip molded product is deteriorated and the tensile strength is lowered.

As another monomer constituting the copolymer of the latex for rubber gloves according to the present invention, the ethylenically unsaturated nitrile monomer is acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile and α-cyano ethyl acryl At least one selected from the group consisting of nitriles, of which acrylonitrile and methacrylonitrile are preferred, of which acrylonitrile is most preferably used.

The ethylenic unsaturated nitrile monomer is included in an amount of 20 to 50 wt%, preferably 25 to 40 wt% within 100 wt% of the total content of the total monomers constituting the carboxylic acid-modified nitrile copolymer. If the ethylenically unsaturated nitrile monomer content is less than the above range, not only the oil resistance of the dip molded article is lowered, but also the tensile strength is lowered. Occurs.

In particular, the copolymer latex of the present invention has an excess of anions present on the surface, which anions are derived from unsaturated carboxylic acid monomers and unsaturated dicarboxylic acid monomers.

The unsaturated carboxylic acid monomer is one of acrylic acid and methacrylic acid, and preferably methacrylic acid is used.

The unsaturated carboxylic acid monomer is included in an amount of 2 to 10% by weight, preferably 4 to 7% by weight within 100% by weight of the total content of the total monomers constituting the carboxylic acid-modified nitrile copolymer. When the content of the unsaturated carboxylic acid monomer is less than the above range, the dip molded article is lowered in tensile strength. On the contrary, when the content of the unsaturated carboxylic acid monomer exceeds the above range, the dip molded article is hardened and wear is poor.

The unsaturated dicarboxylic acid monomer may be at least one selected from the group consisting of itaconic acid, maleic acid, fumaric acid, and glutamic acid, and preferably itaconic acid or fumaric acid may be used.

The unsaturated dicarboxylic acid monomer is used at 0.1 to 3.0% by weight, more preferably 0.5 to 2.5% by weight within 100% by weight of the total content of the total monomers constituting the carboxylic acid-modified nitrile copolymer. The unsaturated dicarboxylic acid monomer serves to strengthen the bond with the polyvalent metal cation for crosslinking, and serves to increase the durability and chemical resistance of the dip molded product. If it is less than the above range, the effect of improving the physical properties of the dip molded article can not be expected, on the contrary, if the above range is exceeded, the dip molded article becomes hard.

Sulfur oxyanion compounds represent sulfur anions including sulfur and oxygen in the molecular structure, and have a sulfate group (SO ₃ ⁻ , sulfate) or sulfonate group (SO ₄ ^2- , sulfonate) in the molecular structure Means. The sulfur oxygen anion compound is present in the copolymer latex, has a strong anionicity on the surface, and due to this anionicity serves to further strengthen the ionic bond with the polyvalent metal cation added for crosslinking.

Such sulfur oxyanion compounds may be used as long as the compound has a sulfate group or a sulfonate group in the molecular structure as mentioned above. However, one should be selected from the group consisting of a persulfate initiator, sodium allyl sulfonate, and sodium styrene sulfonate, since it should not affect the physical properties of the final molded dip product. The persulfate initiator may include sodium persulfate, potassium persulfate, or ammonium persulfate, and when used, sodium allyl sulfonate or sodium styrene sulfonate may be excluded. In addition, when using sodium allyl sulfonate or sodium styrene sulfonate, it is possible to use potassium perphosphate, hydrogen peroxide, or the like which is not a persulfate-based initiator.

The sulfur oxyanion compound is used in an amount of 0.1 to 2.0 parts by weight, more preferably 0.5 to 1.7 parts by weight, based on 100 parts by weight of the total content of the total monomers constituting the carboxylic acid-modified nitrile copolymer in order to obtain the above-described effect. If it is less than the above range, the effect of improving the physical properties of the dip molded article can not be expected, on the contrary, if the above range is exceeded, the dip molded article becomes hard.

The carboxylic acid-modified nitrile copolymer latex of the present invention can be prepared by emulsion polymerization by adding an emulsifier, a polymerization initiator, a molecular weight regulator, and the like to the monomer constituting the carboxylic acid-modified nitrile copolymer as mentioned above.

However, in order to increase the content of the anionic compound on the surface of the copolymer latex particles, the manner of addition of the anionic compound is controlled during the polymerization process. In other words, the anionic compounds having an anionic group are unsaturated carboxylic acid monomers, unsaturated dicarboxylic acid monomers, and sulfur oxyanion compounds, which are divided into a part of the total dose at a polymerization conversion rate of 10% to 50% after the polymerization proceeds. The concentration is concentrated on the surface of the copolymer latex.

Specifically, the carboxylic acid-modified nitrile copolymer latex

(Step a) adding a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer and a sulfur oxyanion compound, an emulsifier, a polymerization initiator and deionized water to the reactor,

(Step b) performing emulsion polymerization,

(C) after the polymerization is carried out, a partial division of the total amount of one or more anionic compounds selected from among unsaturated carboxylic acid monomers, unsaturated dicarboxylic acid monomers, and sulfur oxyanion compounds is performed at a polymerization conversion rate of 10% to 50%. Steps and

(Step d) to proceed through the step of completing the polymerization after the preparation.

Hereinafter, each step will be described in detail.

First, emulsion polymerization is performed by adding a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound, an emulsifier, a molecular weight regulator and a polymerization initiator in deionized water (step a).

The composition of the conjugated diene monomer, ethylenically unsaturated nitrile monomer, unsaturated carboxylic acid monomer, unsaturated dicarboxylic acid monomer and sulfur oxyanion compound is as mentioned above.

Any emulsifier can be used as long as it is used for normal emulsion polymerization, and is not particularly limited in the present invention. As an example, anionic surfactants, nonionic surfactants, and the like can be used. Among these, anionic surfactants selected from the group consisting of alkylbenzene sulfonates, aliphatic sulfonates, sulfuric acid ester salts of higher alcohols, α-olefin sulfonates and alkyl ether sulfuric acid ester salts may be particularly preferably used.

The use amount of the emulsifier is specifically 0.3 to 10 parts by weight, more specifically 0.8 to 8 parts by weight, most specifically 1.5 to 6 parts by weight based on 100 parts by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer. Used as wealth. If the content of the emulsifier is less than the above range, the stability during polymerization is lowered. On the contrary, if the content of the emulsifier exceeds the above range, foaming increases, making it difficult to manufacture dip molded products.

As the polymerization initiator, one selected from inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide and the like can be used.

The usage-amount of a polymerization initiator is specifically 0.01-2 weight part with respect to 100 weight part of all the monomers which comprise the said carboxylic acid modified nitrile copolymer, More specifically, it contains 0.02-1.5 weight part. If the amount of the polymerization initiator is less than 0.01 parts by weight, the polymerization rate is lowered to make the final product difficult. If the amount is more than 2 parts by weight, the polymerization rate is too fast to control the polymerization rate.

Although it does not specifically limit as a molecular weight regulator, For example, mercaptans, such as (alpha) -methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan; Halogenated hydrocarbons such as carbon tetrachloride, methylene chloride and methylene bromide; Sulfur-containing compounds such as tetraethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropylquixanthogen disulfide; and the like can be given.

These molecular weight modifiers may be used alone or in combination of two or more thereof.

Among these, mercaptans are preferable, and t-dodecyl mercaptan can be used more preferably. Although the usage-amount of a molecular weight modifier changes with the kind, Specifically, 0.1-2.0 weight part, More specifically, 0.2-1.5 weight part, the most with respect to 100 weight part of all monomers which comprise the said carboxylic acid modified nitrile copolymer. Specifically, it is used at 0.3 to 1.0 parts by weight. If the amount of the molecular weight regulator is less than 0.1 part by weight, the physical properties of the dip molded article is significantly lowered, and if it exceeds 2 parts by weight, there is a problem that the polymerization stability is lowered.

Deionized water is used as the medium for emulsion polymerization.

In addition to the above composition, it may further include a conventional additive used for the emulsion polymerization of the latex resin, if necessary. For example, the additive may be an activator, chelating agent, dispersing agent, pH adjusting agent, deoxygenating agent, particle size adjusting agent, anti-aging agent, oxygen scavenger, and the like.

In this step a monomers, emulsifiers, molecular weight modifiers, polymerization initiators and further additives can be added simultaneously or sequentially in the reactor, and suitable methods can be selected by one of ordinary skill in the art. have.

Next, emulsion polymerization of the mixed mixture is performed (step b).

The polymerization temperature in the emulsion polymerization may be usually 10 to 90 ℃, preferably 20 to 80 ℃. More preferably, it may be 25 to 75 ° C, but is not particularly limited.

Next, one part selected from the group consisting of an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer and a sulfur oxyanion compound is dividedly administered under conditions of a predetermined polymerization conversion rate after the progress of polymerization (step c).

The divided dose is carried out at 30% or less of the total dose of each monomer, and this divided dose mode allows a large amount of the anionic compound to exist on the surface of the copolymer latex particles. The divided doses may be added to the remaining monomers at once, or may be continuously added, all of the used content may be added all at once to the polymerization reactor, or some of the content may be added to the polymerization reactor and then the remaining content may be continuously supplied to the polymerization reactor again. have.

In particular, the divided administration is carried out at a polymerization conversion of 50% or less, preferably 10 to 50%.

The polymerization conversion rate of the polymerization reaction can be measured by a method commonly known in the art. For example, after a certain amount of samples were taken from the reaction composition at regular time intervals and the solid content was measured, the polymerization conversion rate was calculated by Equation 1 below.

[Equation 1]

Polymerization Conversion Rate (%) = (Ms-Mo) / (Mp-M'o)

(In Equation 1,

Ms is the dry copolymer latex weight,

Mo is the sum of emulsifier and initiator weight,

Mp is the weight of 100% polymerized polymer,

M'o is the sum of emulsifier and initiator weight)

The addition of a part of the anionic compound before the polymerization conversion rate of 10% is no different from that of the beginning. If it is added after 50%, the anionic compound is not copolymerized in the copolymer and thus the unreacted anionic compound is detected in the serum. The amount increases.

At this time, the amount of the anionic compound to be added is preferably 30% or less of the total amount. When this amount is added, there may be a problem that the amount of unreacted anionic compound detected in the serum increases or the stability of the polymerization reaction decreases.

Next, the polymerization reaction is terminated to obtain a rubber latex copolymer latex (step d).

The completion of the polymerization reaction is carried out after the polymerization conversion is at least 90%, preferably at least 93%. The completion of the polymerization reaction is carried out by addition of a polymerization inhibitor, a pH adjusting agent and an antioxidant.

The final copolymer latex obtained after completion of the reaction is used after removing the unreacted monomer through a conventional deodorization concentration process.

The carboxylic acid-modified nitrile copolymer latex has a glass transition temperature of -40 to -15 ° C, preferably -35 to -20 ° C. When the glass transition temperature of the latex is less than the above range, the tensile strength is significantly lowered or the wearability is reduced due to the stickiness of the gloves. On the contrary, when the glass transition temperature of the latex is higher than the above range, dip molded product cracks are not preferable. The glass transition temperature can be adjusted by adjusting the content of the conjugated diene monomer, it can be measured by differential scanning calorimetry (Differential Scanning Calorimetry).

The average particle diameter of the dip molding latex may be 80nm to 300nm. If the average particle diameter of the dip molding latex falls within the above range, the tensile strength of the manufactured dip molded article may be improved.

The average particle diameter of the dip molding latex may be adjusted by adjusting the type or content of the emulsifier, and the average particle diameter may be measured by a laser scattering analyzer (Nicomp).

Carbonic Acid Modified Nitrile Copolymer Latex Composition

The carboxylic acid-modified nitrile copolymer latex according to the present invention as mentioned above may be used as a latex composition for dip molding or through the addition of a composition (or additive) commonly used in manufacturing dip molded articles. To prepare.

 In particular, the latex composition for dip molding according to the present invention is ionic bonds (ie, crosslinking) present in a large amount on the surface of the copolymer latex particles to enable crosslinking without using sulfur and a vulcanization accelerator or a crosslinking agent such as zinc oxide. Multivalent metal cation compounds are used to make this possible.

The polyvalent metal cation compound may be one of salts of trivalent or more metal cations such as aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum lactate, aluminum acetylacetonate, and preferably aluminum acetylacetonate.

The polyvalent metal cation compound may cause ionic bonds with carboxyl groups present on the surface of the copolymer latex particles to increase durability and chemical resistance of the dip molded product. As a result, the content of the polyvalent metal cation compound is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 4 parts by weight, based on 100 parts by weight of the carboxylic acid-modified nitrile copolymer latex. If the content is less than the above range, problems such as tearing during use may occur due to low durability and chemical resistance, and if used in excess of the above range, it may become hard.

As described above, the mechanism of crosslinking by ionic bonding of anions and metal cations is weakened in the acidic solution, sweat and polar solvents. In particular, dip molded articles such as gloves often deal with acidic solutions such as vinegar acid in the food and chemical fields, and metal cations are eluted by the acidic solution. In particular, when zinc oxide is used as a crosslinking agent, the amount of zinc ions eluted is substantially regulated. In addition, it can be weakened by the main component of the human sweat, the bond to the polar solvent can be easily broken and the chemical resistance can be lowered.

The latex composition for dip molding according to the present invention performs crosslinking using an aluminum-based polyvalent metal cation compound instead of zinc oxide as a crosslinking agent, and the prepared dip molded article has a high content of eluted when immersed in an acidic solution and high It is excellent in chemical resistance as well as durability by sweat.

The elution of metal cations is quantified by analyzing the content of metal cations in the eluate which is eluted in an acid solution of known concentration for a certain time by ICP-OES (inductively coupled plasma optical emission spectrometry). In this case, the lower the value, the less the content of the metal cation eluted.

The extract is obtained by cutting a dip molded product into an area of 10 * 10 cm ² , immersing in 200 g of 4% acetic acid aqueous solution, and then extracting at 60 ° C. for 30 minutes. The dip molded article according to the present invention manufactured through this method satisfies less than 0.1 ppm of aluminum ions extracted from the acid solution. This value means that the ionic binding force between the anion and the metal cation is very high, and that even when used in an acidic solution such as vinegar, the amount of metal eluted is very low.

In addition, the durability against sweat was measured by the time of tearing with a glove-shaped dip molded product in the hand, it was able to maintain the durability even when continuously worn for 4 hours or more. In addition, the chemical resistance was measured according to EN374-3: 2003, and the result of using hexane (hexane) as the penetration solvent showed an excellent result of 40 minutes or more.

The latex composition for deep molding capable of crosslinking by an ionic bond between an anion and a metal cation, which can secure the excellent effect as described above, may further include various additives in addition to the polyvalent metal cationic compound for manufacturing various products.

As the additive, an additive used in dip molding may be used, such as a pigment such as titanium dioxide, a filler such as silica, a thickener, or a pH adjusting agent such as ammonia or alkali hydroxide.

In addition, the latex composition for dip molding according to the present invention has a solid content of 5 to 40% by weight, preferably 8 to 35% by weight, more preferably 10 to 33% by weight. If the concentration is too low, the efficiency of transportation of the latex composition is lowered. If the concentration is too high, the solid content concentration may cause an increase in viscosity and may cause problems such as storage stability. Therefore, the concentration is appropriately adjusted within the above range.

In addition, the dip molding latex composition may have a pH of 9 to 12, preferably 9 to 11, and more preferably 9.5 to 10.5.

In addition, the pH of the latex composition according to the present invention can be adjusted by adding a certain amount of pH regulator, the pH regulator may be mainly used 1 to 5% potassium hydroxide aqueous solution or 1 to 5% ammonia water.

Dip molding

In addition, the present invention provides a dip molded article prepared from the latex composition for dip molding.

As already mentioned, the latex composition for dip molding can be crosslinked only by an ionic bond of an anion and a polyvalent metal cation, and is equivalent to or more physical properties, particularly crosslinking, compared to a dip molded product using a crosslinking agent such as sulfur and vulcanization accelerator or zinc oxide. Directly related durability and chemical resistance can be ensured and the elution of polyvalent metal cations of less than 0.1 ppm in acid solution.

As a dip molding method for obtaining the dip molded article of the present invention, a conventional method can be used, and examples thereof include a direct dipping method, an anode adhesion dipping method, and a Teague adhesion dipping method. Among them, the positive electrode adhesion dipping method is preferable because a dip molded article having a uniform thickness can be easily obtained.

Method for producing a dip molded article using the composition of the present invention

(a) coating a coagulant solution on the mold surface;

(b) forming a dip molding layer by coating a latex composition for dip molding on a mold coated with a coagulant;

(c) crosslinking the dip molding layer; And

(d) peeling off the cross-linked dip molding layer from the mold to obtain a dip molded article.

Hereinafter, the method of manufacturing a dip molded article using the latex composition of this invention is demonstrated in detail.

(a) coating a coagulant on the mold surface

In the step (a), a dip mold having a hand shape is used as a mold, and the mold is coated on a coagulant solution and dried to apply a coagulant to the mold surface.

Coagulants include metal halides such as barium chloride, calcium chloride, magnesium chloride, zinc chloride and the like; Nitrates such as barium nitrate, calcium nitrate and zinc nitrate; Acetates such as barium acetate, calcium acetate and zinc acetate; Sulfates such as calcium sulfate and magnesium sulfate. Of these, calcium chloride and calcium nitrate are preferred. The coagulant solution is a solution in which such coagulant is dissolved in water, alcohol or a mixture thereof. The concentration of coagulant in the coagulant solution is usually 5 to 50% by weight, preferably 10 to 40% by weight.

(b) forming a dip molding layer in the mold

Following step (a), in step (b), a mold having a coagulant attached is immersed in the latex composition for dip molding of the present invention to form a dip molding layer.

The mold to which the coagulant is stuck is immersed in the latex composition for rubber gloves of the present invention, and then the mold is taken out to form a dip molding layer on the mold.

(c) crosslinking the dip molding layer;

Next, in the step (c), a step of crosslinking the latex resin is performed by heating the dip molding layer formed on the mold.

The crosslinking is carried out by heat treatment, in which the water component evaporates first and curing through crosslinking is carried out.

(d) obtaining a dip molded article and measuring physical properties

Subsequently, in this step (d), a dip molded product is obtained from the mold, and the physical properties of the obtained dip molded product are measured.

Dumbbell-shaped specimens were produced from the obtained dip molded articles in accordance with ASTM D-412. This specimen is then drawn using a universal testing machine (UTM) at an elongation rate of 500 mm / min, the tensile strength and elongation at break are measured, and the touch is measured by stress at 300% and 500% elongation.

The process according to the invention can be used for any latex article which can be produced by known dip molding methods. Specifically, it can be applied to dip molded latex articles selected from health care products such as surgical gloves, examination gloves, condoms, catheters or various kinds of industrial and household gloves.

Most preferably, household or industrial gloves can be used, and especially gloves used in the food industry. The gloves can be used safely because the elution of the metal cation is less than 0.1ppm when exposed to an acidic solution, and does not use sulfur and vulcanization accelerators with a soft touch, so that the allergy caused by this does not occur. In addition, it has an advantage of excellent durability against sweat and high chemical resistance to various organic solvents.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are only for exemplifying the present invention, and various changes and modifications within the scope and spirit of the present invention will be apparent to those skilled in the art. And modifications fall within the scope of the appended claims.

EXAMPLE

Example 1

(1) Preparation of copolymer latex for rubber gloves

A monomer mixture consisting of 32% by weight of acrylonitrile, 61.5% by weight of 1,3-butadiene, 4.5% by weight of methacrylic acid, and 1% by weight of itaconic acid and 99 parts by weight of t-dodecylmercaptan 0.7 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate, and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.0 weight% of methacrylic acid was added when the polymerization conversion was 30%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5.

(2) Preparation of Dip Molded Products

2.0 parts by weight of potassium hydroxide solution, 1.0 parts by weight of aluminum acetylacetonate, 1.0 parts by weight of titanium oxide (BOSTEX 497D) and secondary distilled water were added to 100 parts by weight of the latex to obtain a dip molding composition having a solid content concentration of 20% and pH 10. .

Separately, a coagulant solution was prepared by mixing 15 parts by weight of calcium nitrate, 84.5 parts by weight of water, and 0.5 parts by weight of wetting agent (Teric 320 produced by Huntsman Corporation, Australia). The hand-shaped ceramic mold was immersed in this solution for 20 seconds, pulled out, and dried at 70 ° C. for 3 minutes to apply a coagulant to the hand-shaped mold.

Next, the mold to which the coagulant was applied was immersed in the dip molding composition for 20 seconds, pulled up, dried at 70 ° C. for 2 minutes, and then immersed in water or hot water for 3 minutes to leach. The mold was dried at 70 ° C. for 3 minutes and crosslinked at 130 ° C. for 20 minutes. The crosslinked dip molding layer was peeled off from the hand-shaped mold to obtain a dip molded article in the form of a glove.

Example 2

A monomer mixture comprising 32% by weight of acrylonitrile, 61.5% by weight of 1,3-butadiene, 5.0% by weight of methacrylic acid, and 0.5% by weight of fumaric acid and t-dodecylmercaptan based on 99 parts by weight of the monomer mixture 0.7 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate, and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.0 wt% sodium allyl sulfate was added at the time of 20% polymerization conversion.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Example 3

A monomer mixture consisting of 34% by weight of acrylonitrile, 60% by weight of 1,3-butadiene, 4.0% by weight of methacrylic acid and 0.5% by weight of fumaric acid and t-dodecylmercaptan based on 98.5 parts by weight of the monomer mixture 0.7 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate, and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.5 wt% of methacrylic acid was added when the polymerization conversion was 20%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Example 4

A monomer mixture consisting of 33% by weight of acrylonitrile, 61% by weight of 1,3-butadiene, 4.0% by weight of methacrylic acid, 0.5% by weight of itaconic acid, and 0.5% by weight of sodium allyl sulfate and 99 parts by weight of the monomer mixture 0.7 parts by weight of t-dodecyl mercaptan, 2 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate, and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.0 weight% of methacrylic acid was added when the polymerization conversion was 40%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Example 5

A monomer mixture consisting of 33% by weight of acrylonitrile, 60.5% by weight of 1,3-butadiene, 5% by weight of methacrylic acid, and 0.5% by weight of sodium allyl sulfate and t-dodecylmer relative to 99 parts by weight of the monomer mixture 0.7 parts by weight of captan, 2 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.0 weight% of itaconic acid was added at the time of 30% of a polymerization conversion rate.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Example 6

A monomer mixture consisting of 33% by weight of acrylonitrile, 60.5% by weight of 1,3-butadiene, 5% by weight of methacrylic acid, and 0.5% by weight of sodium allyl sulfate and t-dodecylmer relative to 99 parts by weight of the monomer mixture 0.7 parts by weight of captan, 2 parts by weight of sodium dodecyl benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water were added, and polymerization was started at a temperature of 36 ° C.

1.0% by weight of fumaric acid was added when the polymerization conversion was 40%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Comparative example  One

A monomer mixture consisting of 24.5% by weight of acrylonitrile, 72% by weight of 1,3-butadiene and 3.5% by weight of methacrylic acid, and 0.5 parts by weight of t-dodecylmercaptan and 100 parts by weight of the monomer mixture After adding 2 parts by weight of the actual benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 40 ° C.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Comparative Example 2

A monomer mixture consisting of 30% by weight of acrylonitrile, 65% by weight of 1,3-butadiene, and 4.0% by weight of methacrylic acid, and 0.5 parts by weight of t-dodecylmercaptan, sodium dode based on 99 parts by weight of the monomer mixture After adding 2 parts by weight of the actual benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 40 ° C.

1.0 wt% of methacrylic acid was added when the polymerization conversion was 60%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5. Using the latex thus obtained, a dip molded article was prepared in the same manner as in Example 1.

Comparative Example 3

A monomer mixture consisting of 32% by weight of acrylonitrile, 62% by weight of 1,3-butadiene and 6.0% by weight of methacrylic acid, and 0.5 parts by weight of t-dodecylmercaptan, sodium dode based on 100 parts by weight of the monomer mixture After adding 2 parts by weight of the actual benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 40 ° C.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5.

1.8 parts by weight of potassium hydroxide solution, 1.5 parts by weight of sulfur latex (BOSTEX 378, Akron dispersions) 1.5 parts by weight of zinc oxide (BOSTEX422), 0.7 parts by weight of vulcanization accelerator (BOSTEX 497B), 1.0 parts by weight of titanium oxide (BOSTEX 497D) ) And secondary distilled water were added to obtain a dip molding composition having a solid content concentration of 20% and pH 10. A dip molded article was manufactured in the same manner as in Example 1 using this composition.

Comparative Example 4

A monomer mixture consisting of 24% by weight of acrylonitrile, 72% by weight of 1,3-butadiene and 4.0% by weight of methacrylic acid, and 0.5 parts by weight of t-dodecylmercaptan and 100 parts by weight of the monomer mixture After adding 2 parts by weight of the actual benzenesulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 40 ° C.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted substance was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a copolymer latex for rubber gloves having a solid content of 45% and a pH of 8.5.

1.8 parts by weight of potassium hydroxide solution, 2.0 parts by weight of zinc oxide (BOSTEX422), 1.0 part by weight of titanium oxide (BOSTEX 497D) and secondary distilled water were added to 100 parts by weight of the latex to form a dip molding composition having a solid content concentration of 20% and pH 10. Got it. A dip molded article was manufactured in the same manner as in Example 1 using this composition.

Experimental Example 1: Measurement of properties of latex and dip molding

1. Measurement of physical properties of copolymer latex

The physical properties of the copolymer latex prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Tables 1 to 2 below.

Distribution of Carboxylic Acid in Copolymer

In order to confirm the distribution of anions in the presence on the surface of the copolymer particles, carboxylic acids, which are representative anions, were quantified.

The latex obtained by polymerization was diluted to 10%, and then the pH was raised to 12 using 3% potassium hydroxide aqueous solution, followed by stirring at 90 ° C for 2 hours. Subsequently, the ammonia in the aqueous solution was removed, the dilution liquid was cooled to room temperature, and then the pH was lowered to 2 or less using an aqueous hydrochloric acid solution diluted to 2%, followed by stirring at a temperature of 90 ° C. for 2 hours. Next, the carbon dioxide in the aqueous solution was removed, the obtained diluted solution was cooled to room temperature, and titrated with an accurate 3% potassium hydroxide aqueous solution to calculate the amount of carboxylic acid bound to the particle surface.

FIG. 1 is a graph showing pH change according to KOH input, wherein the amount of carboxylic acid calculated as KOH input between the first and second inflection points of FIG. 1 is the amount of acid present on the surface.

At this time, the surface present content in Table 1 to Table 2 means the content of the anion compound. The content of the anion compound assumes that all of the sulfur oxygen anions are present on the surface (the sulfur oxygen anions are present on the surface even when the pH is low, so they exist on the surface). From the anion content present on the surface was calculated.

(Analysis of the amount of carboxylic acid remaining in the serum of latex)

In order to quantify the amount of anion present in the latex serum without being present on the surface of the copolymer particles, carboxylic acid, which is a representative anion, was quantified.

4 g of acetonitrile was added to 1 g of the sample, precipitated, centrifuged, the supernatant was collected, analyzed by GC / FID, and the amount of carboxylic acid remaining in the serum was not determined without binding to the copolymer.

2 is an analysis spectrum with GC / FID (gas chromatograph (GC) / flame ionization detector (FID)), which can measure the amount of carboxylic acid remaining in the serum.

2. Measurement of properties of dip molded products

The physical properties of the dip molded articles prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Tables 1 to 2 below.

(thickness)

The thickness was measured using a digital thickness meter.

(Tensile strength, elongation, modulus)

Dumbbell-shaped test pieces were produced from dip molded products in accordance with ASTM D-412. This test piece was then pulled at an elongation rate of 500 mm / min, and the modulus (stress) at 300% elongation, the tensile strength at break and elongation were measured.

(Analysis of the amount of metal cations extracted from acid solution)

The dip molded product was cut to 100 cm ² , and then placed in 200 g of 4% acetic acid solution and extracted at 60 ° C. for 30 minutes. The eluate was analyzed by ICP-OES (inductively coupled plasma optical emission spectrometry) to quantify the amount of metal cations present in the solution.

(Measurement method of the durability)

A glove-shaped dip molded article was made and measured for hours without tearing in the hand.

(Measurement method of chemical resistance)

The measurement of chemical resistance from dip molded parts is carried out in accordance with EN374-3: 2003. EN374-3: 2003 and are manufactured in accordance with the specimen to specimen diameter 51mm and depth abut the chemical, hexane (hexane) to be measured contained in a 35mm experimental containers of hexane 1μg / cm ² / min The chemical resistance can be measured by measuring the time it takes to penetrate the specimen at speed.

		Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
Latex properties	Surface carboxylic acid content (% by weight)	6.02	5.38	5.74	5.25	5.66	5.81
	Carboxylic acid content of the serum (% by weight)	0.06	0.04	0.08	0.06	0.2	0.05
	Content of anionic compounds present on the surface (% by weight)	92.6	97.8	95.7	95.5	92.7	96.8
Glove Properties	Thickness (mm)	0.065	0.064	0.065	0.065	0.064	0.065
	Tensile Strength (MPa)	36.3	35	37.5	35	35.7	37
	% Elongation	588	598	600	617	580	600
	300% modulus (MPa)	7.6	6.6	6.8	6.4	7.2	6.9
	Durability (hours)	> 4 hours	> 4 hours	> 4 hours	> 4 hours	> 4 hours	> 4 hours
	Chemical resistance (breakthrough time)	40 minutes	40 minutes	40 minutes	40 minutes	40 minutes	40 minutes
	Cation extraction content	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm

		Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Latex properties	Surface carboxylic acid content (% by weight)	3.3	3.9	5.72	3.81
	Carboxylic acid content of the serum (% by weight)	0.04	0.5	0.07	0.06
	Content of anionic compounds present on the surface (% by weight)	74.3	68.0	75.3	75.3
Glove Properties	Thickness (mm)	0.064	0.065	0.063	0.065
	Tensile Strength (MPa)	20	24	36	29
	% Elongation	580	610	567	604
	300% modulus (MPa)	4.0	5.8	8.1	6.2
	Durability (hours)	10 minutes	50 minutes	> 4 hours	10 minutes
	Chemical resistance (breakthrough time)	6 minutes	10 minutes	35 minutes	5 minutes
	Cation extraction content	Al 3 + <0.1 ppm	Al 3 + <0.1 ppm	Zn 2 + 40 ppm		Zn 2 + 100 ppm

Referring to Table 1, in the case of the deep molded article of Examples 1 to 6 has a high content of the surface carboxylic acid of 5.25 to 6.02% by weight, excellent durability and chemical resistance, anionic compounds and polyvalent cationic It can be seen that the desired level of physical properties can be achieved even by crosslinking according to the ionic bonding of the compound. In addition, the aluminum cation extracted in the acidic solution is less than 0.1 ppm, it can be seen that the aluminum cation strongly maintains the ionic bond.

Referring to Table 2, in the case of Comparative Example 1, if the anionic compound is not additionally divided administration, the content of the carboxylic acid present on the surface is lowered to about 50% level, which is highly durable and chemical resistance The result was a degradation.

Therefore, as in Comparative Example 2, the content of carboxylic acid slightly increased when the polymerization conversion rate was dividedly administered at 60% level, thereby increasing durability and chemical resistance slightly.

In addition, as in Comparative Examples 3 and 4, when zinc oxide was used as the crosslinking agent, the physical properties were partially similar to those of Examples 1 to 4, but serious problems such as an increase in zinc cations eluted from the zinc oxide increased to 100 ppm. It was.

The latex composition for dip molding according to the present invention can be used for the production of latex articles such as health care products such as various industrial and household gloves.

Claims (14)

1. In a carboxylic acid-modified nitrile copolymer latex copolymerized including a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound,

   A carboxylic acid-modified nitrile copolymer latex, characterized in that at least 80% by weight of the total content of the unsaturated carboxylic acid monomer, unsaturated dicarboxylic acid monomer and sulfur oxyanion compound is copolymerized on the surface of the latex particles.
2. The method of claim 1,

   The carboxylic acid-modified nitrile copolymer is 35 to 80% by weight conjugated diene monomer, 20 to 50% by weight ethylenically unsaturated nitrile monomer, 2 to 10% by weight unsaturated carboxylic acid monomer and 0.1 to 3% by weight unsaturated dicarboxylic acid monomer Carbonic acid-modified nitrile copolymer latex, characterized in that copolymerized using 0.1 to 2 parts by weight of sulfur oxygen anion compound with respect to 100 parts by weight of the total monomers containing%.
3. The method of claim 1,

   The conjugated diene monomer is at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and isoprene Carbonic acid modified nitrile copolymer latex, characterized in that.
4. The method of claim 1,

   The ethylenically unsaturated nitrile monomer is a carboxylic acid-modified nitrile, characterized in that at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile and α-cyano ethyl acrylonitrile. Copolymer latex.
5. The method of claim 1,

   The unsaturated carboxylic acid monomer is a carboxylic acid-modified nitrile copolymer latex, characterized in that at least one member selected from the group consisting of acrylic acid and methacrylic acid.
6. The method of claim 1,

   The unsaturated dicarboxylic acid monomer is a carboxylic acid-modified nitrile copolymer latex, characterized in that at least one selected from the group consisting of itaconic acid, maleic acid, fumaric acid and glutamic acid.
7. The method of claim 1,

   The sulfur oxyanion compound is a carboxylic acid-modified nitrile copolymer latex, characterized in that at least one selected from the group consisting of a persulfate initiator, sodium allyl sulfonate and sodium styrene sulfonate.
8. A carboxylic acid-modified nitrile copolymer latex is prepared through a polymerization step including a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound.

   At the time of 10 to 50% of the polymerization conversion rate in the polymerization step, the copolymerization is performed by additionally administering any one of an unsaturated carboxylic acid monomer, an unsaturated dicarboxylic acid monomer, and a sulfur oxyanion compound. A method for producing a carboxylic acid-modified nitrile copolymer latex according to any one of claims 1 to 7.
9. The method of claim 8,

   The split administration is a method for producing a carboxylic acid-modified nitrile copolymer latex, characterized in that the total administration of the total unsaturated carboxylic acid monomer, unsaturated dicarboxylic acid monomer and sulfur oxygen anion compound at 30% by weight or less.
10. Carboxylic acid-modified nitrile copolymer latex according to any one of claims 1 to 7; And

    A latex composition for dip molding comprising a polyvalent metal cation compound.
11. The method of claim 10,

    The polyvalent metal cation compound is a dip molding latex composition, characterized in that one selected from the group consisting of aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum lactate and aluminum acetylacetonate.
12. The method of claim 10,

    The latex composition for dip molding is a latex composition for dip molding comprising 0.1 to 5 parts by weight of a polyvalent metal cation compound based on 100 parts by weight of a carboxylic acid-modified nitrile copolymer latex.
13. A dip molded article prepared by dip molding the latex composition for dip molding according to claim 10.
14. The method of claim 13,

    Dip molded article, characterized in that the content of the metal cation flowing out from the dip molded article is less than 0.1ppm.

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