KR102081762B1 - Carboxylic acid modified-nitrile based copolymer latex, Preparation method thereof, Composition for Dip-Forming and Dip-Formed Article comprising the same - Google Patents

Abstract

The present invention relates to a carboxylic acid-modified nitrile copolymer latex, a method for preparing the same, a latex composition for forming a dip comprising the same, and a molded article prepared therefrom. The conjugated diene monomer, the ethylenically unsaturated nitrile monomer and the ethylenically unsaturated acid Carbonate-modified nitrile-based copolymer latex, which enables the preparation of dip molded articles having high strength even though the thickness is small by controlling the addition of molecular weight modifiers in the preparation of carboxylic acid-modified nitrile-based copolymer latex by emulsion polymerization of monomer in the presence of an emulsifier. It relates to a manufacturing method, a latex composition for dip molding comprising the same and a molded article prepared therefrom.

Description

Carboxylic acid modified-nitrile based copolymer latex, Preparation method according, Composition for Dip-Forming and Dip-Formed Article comprising carboxylic acid-modified nitrile copolymer latex, preparation method thereof, latex composition for dip molding comprising same, and dip molded article the same}

The present invention relates to a carboxylic acid-modified nitrile copolymer latex having a high tensile strength even at a thin thickness, a method for preparing the same, a latex composition for dip molding including the same, and a dip molded article.

Disposable rubber gloves used in a variety of everyday life, such as household, food, electronics, medical, etc. are made by dip molding of natural rubber or carboxylic acid-modified nitrile copolymer latex. Recently, carboxylic acid-modified nitrile-based gloves have been in the spotlight in the disposable gloves market due to allergic problems due to natural protein of natural rubber and unstable supply and demand.

On the other hand, there are various attempts to increase glove productivity to meet the growing demand for gloves. The most common use of these attempts is to maintain the strength while thinning the glove. In the past, disposable nitrile gloves weighing about 4 grams were commonly used, but now require gloves that are as thin as 3.2 grams and have tensile strengths greater than 6 N. However, even with the aging process, it is not easy to achieve 6N tensile strength in 3.2g thin gloves.

Glove manufacture through dip molding requires crosslinking treatment in an oven after the dipping process, and long crosslinking treatment is required for high tensile strength. However, since the crosslinking treatment is performed for a short time in order to reduce the cost and shorten the overall process time, it is difficult to secure sufficient tensile strength by the crosslinking treatment alone.

Accordingly, there has been a demand for the development of carboxylic acid-modified nitrile copolymer latexes capable of securing high tensile strength even if they are made thin in a high speed production line.

In response to these demands, various studies have been conducted to develop latex for making gloves having high strength.

One such attempt, US Patent Publication No. 2006-0235158, adds acrylonitrile and methacrylic acid after a polymerization conversion rate of 50%, and methyl ethyl ketone (hereinafter referred to as 'MEK') insoluble content is 70 to 90. When preparing a carboxylic acid-modified nitrile copolymer latex of%, it is described that it is possible to prepare gloves having excellent oil resistance and high strength. However, when methacrylic acid is added after the polymerization conversion rate of 50%, all of the added methacrylic acid does not bind to the copolymer, and thus, unreacted methacrylic acid remains in the final latex, resulting in various problems.

On the other hand, US Patent Publication No. 2006-0235158 refers to a technique related to the MEK insoluble content of the copolymer latex.

MEK insolubles are parameters related to the crosslinked structure of the copolymer, and high MEK insolubles mean that the crosslinked structure is formed high. This patent discloses that with respect to MEK insolubles, when the value is 70% or less, the resistance to organic solvents is lowered. However, resistance to organic solvents is a feature that can be obtained when crosslinking by vulcanization is sufficient, and the meaning of the high MEK insoluble content of 70% or more acts as a factor that inhibits crosslinking by vulcanization. Moreover, when a glove is manufactured using latex having such a high level of MEK insolubles, a glove having a high modulus, low elongation and strength, and a hard feel is produced.

In connection with the quality of gloves with the MEK insolubles, US Patent No. 7,662,890 discloses the content of acid monomers. The '890 patent suggests that the tensile strength of gloves can be improved by the bonding between zinc oxide and acid monomers.

The above-mentioned U.S. Patent Publication No. 2006-0235158 and Patent No. 7,662,890 provide techniques for improving the physical properties of gloves, but the physical properties of gloves can not be defined solely by the content of MEK insolubles or acid monomers. .

US Patent Publication No. 2006-0235158, "Dipping copolymer latex" US Patent No. 7,662,890, "Composition for dip forming and molding obtained by dip forming"

Accordingly, the present inventors have conducted various researches related to the dip molding process, and as a result, by controlling the administration of the molecular weight modifier in consideration of the polymerization conversion rate during latex production, the carboxylic acid-modified nitrile system having limited parameters for determining the processing properties of the latex for dip molding Copolymer latex was prepared, and the present invention was completed by confirming that the latex was able to manufacture a glove having high tensile strength even at a thin thickness through a dip molding process having a low oven temperature and a fast line speed.

Accordingly, it is an object of the present invention to provide a carboxylic acid-modified nitrile copolymer latex and a preparation method thereof.

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 molded article prepared from the latex composition for dip molding and having excellent tensile strength properties even in a thin thickness.

In addition, another object of the present invention is to provide a method for producing a molded article using the latex composition for dip molding.

In order to achieve the above object, the present invention is copolymerized conjugated diene monomer, ethylenically unsaturated nitrile monomer and ethylenically unsaturated acid monomer,

The capillary viscosity is 6.0 mm ² / s or more, the amount of MEK insolubles is 10% or less, the sol partial molecular weight is 180,000 or more, and the amount of ethylenically unsaturated acid monomers bonded to the copolymer is 5.0 To 7.0 wt%, the amount of ethylenically unsaturated nitrile monomer bonded to the copolymer is 26 to 35% by weight to provide a carboxylic acid-modified nitrile copolymer latex.

In addition, the present invention is prepared by emulsion polymerization of conjugated diene monomer, ethylenically unsaturated nitrile monomer and ethylenically unsaturated acid monomer to prepare a carboxylic acid-modified nitrile copolymer latex,

Provided is a method for producing a carboxylic acid-modified nitrile copolymer latex prepared by adding a molecular weight modifier at a time point of polymerization conversion of 60% or more after polymerization progress.

In addition, the present invention provides a latex composition for dip molding comprising the carboxylic acid-modified nitrile copolymer latex.

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

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

The carboxylic acid-modified nitrile copolymer latex according to the present invention has high metal bonding and crosslinking efficiency with sulfur due to zinc oxide, and thus a thin film can be formed within a short time.

The latex can be manufactured at a low oven temperature and a high line speed through a dip molding process, and the gloves thus obtained have excellent mechanical properties even with a thin thickness.

In the manufacture of molded articles such as rubber gloves through the dip molding process, a specific composition is added or process parameters are changed to improve the physical properties and the dip molding process of the final molded article. Accordingly, the present invention provides a carboxylic acid-modified nitrile-based copolymer latex having limited parameters for determining the processing properties of the latex for dip molding by controlling the method of adding a molecular weight modifier when preparing the carboxylic acid-modified nitrile-based latex.

Carboxylic Acid Modified Nitrile Copolymer Latex

The carboxylic acid-modified nitrile copolymer latex according to the present invention is emulsion polymerization by adding an emulsifier, a polymerization initiator, a molecular weight regulator and other additives to a monomer including a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, and an ethylenically unsaturated acid monomer. To make it.

The carboxylic acid-modified nitrile copolymer latex prepared according to the above-described manufacturing method has a specific value in certain parameters. These parameters include capillary viscosity, the amount of ethylenically unsaturated acid monomers bound to the copolymer, the amount of ethylenically unsaturated nitrile monomers bound to the copolymer, the molecular weight of the sol portion and the MEK insoluble content. From these parameters, information on the degree of crosslinking, molecular weight, and degree of crosslinking with metal ions can be effectively obtained, and the copolymer latex is related to enabling the production of dip molded articles having excellent physical properties.

Parameters related to the basic physical properties of the carboxylic acid-modified nitrile copolymer latex of the present invention include the content of MEK insolubles, capillary viscosity, and molecular weight of the sol portion.

MEK insoluble content is one of the methods to determine the characteristics of the latex for dip molding, it is the weight measured by filming the latex and immersed in the MEK solvent, only the remaining film is selected. The higher the value of this MEK insoluble content, the higher the crosslinked structure of the copolymer itself. The MEK insoluble shows only the degree of crosslinking, but no information on the molecular weight.

Capillary viscosity is usually used as a means of measuring the molecular weight of a non-crosslinked polymer. However, in the present invention, an acid monomer capable of bonding with a metal ion in a carboxylic acid-modified nitrile copolymer is present, and in the case of a polymer in which the degree of crosslinking varies according to polymerization conditions, the capillary viscosity is a degree of metal crosslinking of the acid monomer, Butadiene crosslinking degree of the polymer, it was confirmed through a number of experiments to provide a complex information on the molecular weight.

That is, the capillary viscosity is lower when the pH is increased due to the presence of acid, the lower the higher the degree of crosslinking of the polymer. In addition, as the molecular weight of the polymer increases, the capillary viscosity tends to increase.

However, since the MEK insoluble content and the capillary viscosity do not have information on the molecular weight, the present invention proposes to separately measure the molecular weight together with the MEK insoluble content. Molecular weight is measured by GPC (gel permeation chromatography) of the molecular weight of the part dissolved in THF after filming the latex.

Accordingly, in the case of the carboxylic acid-modified nitrile copolymer latex of the present invention, the capillary viscosity is changed depending on the degree of swelling of the copolymer when dissolved in MEK, and the crosslinking degree and molecular weight of the copolymer are predicted from these differences. This becomes possible.

As a result, it is possible to predict the latex structure of the carboxylic acid-modified nitrile copolymer by analyzing the capillary viscosity, the MEK insoluble content and the molecular weight, and in particular, to predict the particle structure of the latex suitable for the high speed dipping process during dip molding. Can be.

The parameters related to the processing properties of the carboxylic acid-modified nitrile copolymer latex together with the basic physical properties include capillary viscosity and the amount of ethylenically unsaturated acid monomer and ethylenically unsaturated nitrile monomer combined with the copolymer.

The ethylenically unsaturated acid monomers may remain in the form of monomers in the aqueous phase of the latex, with most but unreacted being polymerized to the copolymer, depending on the method of addition. The ethylenic unsaturated acid monomer plays an important role in improving the mechanical strength of the dip molded article by forming a metal bond with zinc oxide in the process of making the dip molded article. That is, when the ethylenically unsaturated acid monomer is well bonded to the copolymer (i.e., polymerization), it is effective to improve the mechanical strength and stability of the dip molded product obtained after the dip molding process, but is not bound to the copolymer and is used as an acid monomer in latex. If present, it may adversely affect the stability and strength of the dip molding.

In addition, the ethylenic unsaturated nitrile monomer is also involved in the physical properties of the dip molded product, like the ethylenic unsaturated acid monomer. That is, when the ethylenically unsaturated nitrile monomer is well bonded to the copolymer, it is effective to improve oil resistance, strength, rigidity, and fit of the dip molded product obtained after the dip molding process, but when it is not bound to the copolymer, it is not appropriate to these properties. Crazy

As mentioned above, the carboxylic acid-modified nitrile copolymer latex according to the present invention has its basic properties and the parameters related thereto in consideration of the dip molding process, and within this limited range the metal bond and sulfur by zinc oxide The cross-linking with the film and the formation of its own film are optimized to enable the production of gloves with high tensile strength, even at thin thicknesses, through low oven temperatures and fast line speed dip molding processes. That is, the optimization is not possible if the limited range of any one or more of these parameters is not satisfied.

More specifically, the carboxylic acid-modified nitrile copolymer latex according to the present invention has a MEK insoluble content of 10% or less, and more preferably 6% or less. The capillary viscosity is a viscosity measured using a Cannon-Fenske routine type capillary viscometer and has a range of 6.0 mm 2 / s or more, preferably 6.0 to 10.0 mm 2 / s. . In this case, the sol partial molecular weight is 180,000 or more, and more preferably 20 to 250,000 when the weight average molecular weight.

And the latex has a range of 5.0 to 7.0% by weight, more preferably 5.2 to 6.0% by weight of the ethylenically unsaturated acid monomer bonded to the carboxylic acid-modified nitrile copolymer as a parameter related to processing, ethylenically unsaturated nitrile The amount of monomers is in the range of 26 to 35% by weight, more preferably 29 to 34% by weight.

As described above, the monomers for preparing the carboxylic acid-modified nitrile copolymer latex are conjugated diene monomers, ethylenically unsaturated nitrile monomers, ethylenically unsaturated acid monomers, and unsaturated ethylenic monomers copolymerizable therewith. It is composed.

As the monomer constituting the carboxylic acid-modified nitrile copolymer according to the present invention, specific examples of conjugated diene monomers include 1,3-butadiene, 2,3-dimethyl-1,3-butadiene and 2-ethyl-1 At least one selected from the group consisting of, 3-butadiene, 1,3-pentadiene and isoprene, among which 1,3-butadiene and isoprene are preferable, and among these, 1,3-butadiene is most preferably used.

The conjugated diene monomer is included 40 to 75% by weight, specifically 45 to 70% by weight, most specifically 50 to 68% by weight of the total monomer constituting the carboxylic acid-modified nitrile copolymer. When the conjugated diene-based monomer content is less than the above range, the dip molded article becomes hard and the wear is worse. On the contrary, when the conjugated diene monomer content exceeds the above range, the oil resistance of the dip molded article deteriorates and the tensile strength decreases.

As another monomer constituting the carboxylic acid-modified nitrile copolymer according to the present invention, the ethylenically unsaturated nitrile monomer may be acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile and α-cyano ethyl acryl. At least one selected from the group consisting of ronitrile, of which acrylonitrile and methacrylonitrile are preferred, and acrylonitrile is most preferably used.

The ethylenically unsaturated nitrile monomer is contained in an amount of 20 to 50% by weight, preferably 25 to 40% by weight, of all 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. On the contrary, if the above ethylenic unsaturated nitrile monomer content is exceeded, the dip molded article becomes hard and the wearability is poor. .

In addition, as another monomer constituting the carboxylic acid-modified nitrile copolymer according to the present invention, the ethylenically unsaturated acid monomer includes an ethylenically unsaturated acid monomer containing at least one acidic group selected from the group consisting of a carboxyl group, a sulfonic acid group and an acid anhydride group. to be.

The ethylenically unsaturated acid monomers include, for example, ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid; Polycarboxylic acid anhydrides such as maleic anhydride and citraconic anhydride; Ethylenically unsaturated sulfonic acid monomers such as styrene sulfonic acid; Ethylenic unsaturated polycarboxylic acid partial ester monomers, such as a monobutyl fumarate, a monobutyl maleic acid, and a mono-2-hydroxypropyl maleate, etc. are mentioned, A methacrylic acid is used preferably. Such ethylenically unsaturated acid monomers may be used in the form of alkali metal salts or ammonium salts.

The ethylenically unsaturated acid monomer is included in 4 to 15% by weight, preferably 5 to 10% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer. When the content of the ethylenically unsaturated 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 ethylenically unsaturated acid monomer exceeds the above range, the dip molded article is hardened and wear is poor.

The carboxylic acid-modified nitrile copolymer according to the present invention may further include an ethylenically unsaturated nitrile monomer and other ethylenically unsaturated monomer copolymerizable with the ethylenically unsaturated acid monomer.

The copolymerizable ethylenically unsaturated monomers include vinyl aromatic monomers selected from the group consisting of styrene, alkyl styrene, and vinyl naphthalene; Fluoroalkyl vinyl ethers such as fluoro ethyl vinyl ether; (Meth) acrylamide, N-methylol (meth) acrylamide, N, N -dimethylol (meth) acrylamide, N-methoxy methyl (meth) acrylamide, and N -propoxy methyl (meth) acrylamide Ethylenically unsaturated amide monomers selected from the group consisting of: Non-conjugated diene monomers such as vinyl pyridine, vinyl norbornene, dicyclopentadiene, 1,4-hexadiene; Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, dibutyl maleate, Dibutyl fumarate, diethyl maleate, methoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, cyanomethyl (meth) acrylate, 2-cyano (meth) acrylate Ethyl, 1-cyanopropyl (meth) acrylate, 2-ethyl-6-cyanohexyl (meth) acrylate, 3-cyanopropyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxy (meth) acrylate Using at least one selected from the group consisting of ethylenically unsaturated carboxylic ester monomers selected from the group consisting of propyl, glycidyl (meth) acrylate, and dimethylamino ethyl (meth) acrylate .

The amount of the ethylenically unsaturated nitrile monomer and other ethylenically unsaturated monomer copolymerizable with the ethylenically unsaturated acid monomer may be used within 0.001 to 20% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer, and 20% by weight. If exceeded, there is a poor balance between soft fit and tensile strength.

In particular, in the present invention, the addition method of the molecular weight modifier is adjusted to prepare a carboxylic acid-modified nitrile copolymer latex.

Specifically, when the conjugated diene monomer, ethylenically unsaturated nitrile monomer and ethylenically unsaturated acid monomer are emulsion polymerized in the presence of an emulsifier to prepare a carboxylic acid-modified nitrile copolymer latex, the polymerization conversion rate after the progress of polymerization is 60% or more The reaction is added by adding a regulator.

Specifically, the carboxylic acid-modified nitrile copolymer latex

(Step a) adding a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, an ethylenically unsaturated acid monomer, an emulsifier, a polymerization initiator and deionized water to the reactor;

(Step b) performing emulsion polymerization,

(Step c) adding a molecular weight modifier when the polymerization conversion rate is at least 60% after the polymerization proceeds, 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 ethylenically unsaturated acid monomer, an emulsifier, and a polymerization initiator in deionized water (step a).

The composition of the conjugated diene monomer, ethylenically unsaturated nitrile monomer, and ethylenically unsaturated acid monomer is as described above.

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

Although it does not specifically limit as a polymerization initiator, A radical initiator can be used. As a radical initiator, inorganic peroxides, such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-mentanehydro peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide Organic peroxides such as oxides, 3,5,5-trimethylhexanol peroxide and t-butyl peroxy isobutylate; At least one selected from the group consisting of azobis isobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexane carbonitrile, and azobis isobutyric acid (butyl acid) methyl, and among these radical initiators Inorganic peroxide is more preferable, and a persulfate can be used especially preferably.

The usage-amount of a polymerization initiator is specifically 0.01-2 weight part with respect to 100 weight part of all 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, making it difficult to produce the final product. If the amount is more than 2 parts by weight, the polymerization rate is too fast to control the polymerization rate.

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, a chelating agent, a dispersant, a pH adjusting agent, an oxygen scavenger, a particle size adjusting agent, an anti-aging agent, an oxygen scavenger, or the like.

Preferably, an activator may be used, wherein the activator is at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrrolate, and sodium sulfite Can be selected.

In this step a, monomers, emulsifiers, polymerization initiators and further additives may be used in the reactor at the same time or continuously added, a suitable method can be selected by those skilled in the art.

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

The polymerization temperature during 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, the molecular weight modifier is added when the polymerization conversion rate is 60% or more after the polymerization is carried out (step c).

Copolymer latex of the present invention preferably has a predetermined physical properties (for example, molecular weight and particle size, etc.) in order to produce a dip molded product, it is made through the control of the timing of the introduction of a molecular transfer agent (Chain Transfer Agent).

Preferably, when the polymerization conversion is 60% or more after the emulsion polymerization proceeds, the molecular weight modifier is added.

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

[Equation 1]

% Polymerization conversion = (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)

Although it does not specifically limit as a molecular weight modifier, 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; And sulfur compounds such as tetraethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropyl chianthogen disulfide.

These molecular weight regulators 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 varies with the kind, 0.1-2.0 weight part specifically, 0.2-1.5 weight part, most specifically, 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.

Next, the polymerization reaction is terminated to obtain a carboxylic acid-modified nitrile copolymer latex.

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 adjuster, and an antioxidant.

The carboxylic acid-modified nitrile copolymer latex obtained after the completion of the reaction is used after removing the unreacted monomer through a conventional deodorization concentration process.

In addition, the carboxylic acid-modified nitrile copolymer latex according to the present invention may further add each or all of monomers, emulsifiers, initiators, or both simultaneously with or after the addition of the molecular weight modifier, and preferably further monomers. Can be. These monomers, emulsifiers and initiators can be added together or separately with the molecular weight regulator, and each composition can be introduced into the reactor at one time or continuously.

However, when mercaptans are used as molecular weight regulators, the final copolymer latex may cause odors peculiar to mercaptan compounds if the addition is later than the addition of monomers.

After the addition of the molecular weight regulator, the addition of monomers, emulsifiers, initiators, etc. is used in the range of not more than 20% by weight of the total amount. That is, when the total monomer is 100% by weight, at least 80% by weight is administered during the initial emulsion polymerization reaction, and 20% by weight or less is administered simultaneously with or after the administration of the molecular weight modifier. If the added amount exceeds the above range, the polymerization conversion rate by the addition of the molecular weight modifier is lowered and the reaction time until the completion of the total polymerization is extended, or the physical properties such as molecular weight of the final copolymer latex obtained in the same time are lowered. This results in product defects in the final molded dip product.

All of these molecular weight regulators, monomers, and emulsifiers should be added before the polymerization conversion rate of 85%. If the input is made after the polymerization conversion rate is 85%, the polymerization time may be longer, and productivity may be reduced.If the input is after 85%, the residual monomer in the copolymer latex is increased after the completion of the polymerization. Occurs.

In summary, the carboxylic acid-modified nitrile copolymer latex according to the present invention may be administered with a molecular weight modifier when the polymerization conversion rate is 60% or more, but in some cases, monomers, emulsifiers and initiators may be further added, and the amount thereof is 20% by weight. It should not exceed% and they must complete the input before the polymerization conversion rate is 85%.

The average particle diameter of the carboxylic acid-modified nitrile copolymer latex thus prepared may be 100 to 500 nm, preferably 100 to 200 nm, more preferably 110 to 180 nm. When 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. At this time, the average particle diameter of the carboxylic acid-modified nitrile copolymer latex can be controlled by controlling the type or content of the emulsifier, it can be measured by a laser scattering analyzer (Nicomp).

In addition, the carboxylic acid-modified nitrile copolymer latex is obtained in a water dispersed form, the solid content concentration may be 10 to 30% by weight. If less than 10% by weight, the efficiency of latex transport may be lowered. If it is more than 30% by weight, there may be a problem such as storage stability due to an increase in viscosity.

Dip Molding Composition

The carboxylic acid-modified nitrile copolymer latex according to the present invention as described above may be applied to a dip molding composition to prepare a dip molded article.

The carboxylic acid-modified nitrile copolymer latex composition for dip molding includes a sulfur cross-linking agent, a vulcanization accelerator, a metal oxide such as zinc oxide, a pigment such as titanium dioxide, a filler such as silica, a thickener, ammonia or a pH such as alkali hydroxide. A dip molding composition may be prepared by adding an additive generally used in dip molding such as a regulator.

Such a dip molding composition is capable of forming a thin film within a short time due to the high crosslinking efficiency of the metal bond and zinc by zinc oxide by using the carboxylic acid-modified nitrile copolymer latex according to the present invention.

In particular, the dip molding composition may be manufactured gloves at a low oven temperature and a high line speed through the dip molding process described below, and the gloves thus manufactured can ensure excellent mechanical properties even with a thin thickness.

In addition, the latex composition for dip molding containing an additive such as zinc oxide may have a solid content of 10 to 40% by weight. At this time, if the concentration of the solid content of the composition is too low, the thickness of the dip molded article of the desired level can not be secured, if too high, there may be a problem such as storage stability by causing an increase in viscosity. Preferably it may be 15 to 35% by weight, more preferably 18 to 33% by weight.

In addition, the pH of the dip molding latex composition may be 8 to 12, when the pH concentration is out of the range, the stability of the latex composition for dip molding may be lowered. Preferably 9 to 11, more preferably 9.3 to 10.5.

In addition, the pH of the latex composition for dip molding according to the present invention may be adjusted by adding a certain amount of pH regulator during the preparation of the latex for dip molding, wherein the pH regulator is mainly 1 to 5% aqueous potassium hydroxide solution or 1 to 5 % Ammonia water can be used.

Dip molding

The above-described dip molding composition can be manufactured through a dip molding process. When manufacturing gloves using the dip molding composition, it is possible to secure a tensile strength of 6N level in a thin glove of 3.2g. These properties can be achieved with low oven temperatures, fast line speeds and short cross-linking treatments, reducing the cost and overall process time associated with fabrication of gloves.

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 anode adhesion dipping method is preferable because of the fact that 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) Mold  Coating a coagulant on the surface

In the step (a), a dip-shaped mold of 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 aluminum chloride; 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, magnesium sulfate and aluminum 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) Mold  Dip within Forming layer  Forming steps

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 dip molding made of the latex resin composition of the present invention, and then the mold is taken out to form a dip molding layer on the mold.

(c) dip Forming layer Crosslinked  step

Next, in the step (c), the dip molding layer formed on the mold is heat-treated to crosslink the latex resin.

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

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

Subsequently, in the step (d), a dip molded product is obtained from a 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.

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

EXAMPLE

Example  One

(1) Preparation of carboxylic acid-modified nitrile copolymer latex

A monomer mixture consisting of 29% by weight of acrylonitrile, 65% by weight of 1,4-butadiene, and 6% by weight of methacrylic acid and 0.6 parts by weight of t-dodecyl mercaptan, sodium based on 100 parts by weight of the monomer mixture After adding 2 parts by weight of dodecylbenzene sulfonate, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

At the time when the polymerization conversion was 70%, the polymerization temperature was raised to 50 ° C. and 0.2 part by weight of t-dodecyl mercaptan was added.

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 carboxylic acid-modified nitrile copolymer latex having a solid content of 45% and a pH of 8.5.

(2) Preparation of Dip Molded Articles

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 (BOSTEX 422), 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 15% and pH 10.

Separately, a coagulant solution was prepared by mixing 12 parts by weight of calcium nitrate, 87.5 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, taken 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 cross-linked 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

100 parts by weight of the monomer mixture consisting of 28% by weight of acrylonitrile, 60% by weight of 1,4-butadiene and 6% by weight of methacrylic acid, 0.6 parts by weight of t-dodecyl mercaptan, sodium dodecylbenzene sulfonate After adding 2 parts by weight, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

At the time when the polymerization conversion was 70%, the polymerization temperature was raised to 50 ° C, and 0.2 parts by weight of t-dodecyl mercaptan, 1.0% by weight of acrylonitrile, and 5.0% by weight of 1,4-butadiene were added.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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

100 parts by weight of the monomer mixture consisting of 27% by weight of acrylonitrile, 65% by weight of 1,4-butadiene and 5.5% by weight of methacrylic acid, 0.6 parts by weight of t-dodecyl mercaptan, sodium dodecylbenzene sulfonate After adding 2 parts by weight, 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

When the polymerization conversion rate was 60%, 0.4 parts by weight of t-dodecyl mercaptan was added, and 2.5% by weight of 1,4-butadiene was added at the point where the polymerization conversion rate was 80%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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 30% by weight of acrylonitrile, 60% by weight of 1,4-butadiene and 5.3% by weight of methacrylic acid, 0.5 part by weight of t-dodecyl mercaptan, and 2 parts by weight of sodium dodecylbenzene sulfonate After adding 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

When the polymerization conversion rate was 60%, 0.5 parts by weight of t-dodecyl mercaptan was added, and 4.7% by weight of 1,4-butadiene was added at the point where the polymerization conversion rate was 70%.

When the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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

Monomer mixture consisting of 29% by weight of acrylonitrile, 65% by weight of 1,4-butadiene and 6% by weight of methacrylic acid, 0.6 parts by weight of t-dodecyl mercaptan and 2 parts by weight of sodium dodecylbenzene sulfonate After adding 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

Then, when the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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 29% by weight of acrylonitrile, 65% by weight of 1,4-butadiene and 6% by weight of methacrylic acid, 0.1 part by weight of t-dodecyl mercaptan, and 2 parts by weight of sodium dodecylbenzene sulfonate After adding 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 material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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

In the polymerization reactor, a monomer mixture consisting of 20% by weight of acrylonitrile, 77% by weight of 1,4-butadiene and 3% by weight of methacrylic acid, 0.5 part by weight of t-dodecyl mercaptan, and 2 parts by weight of sodium dodecylbenzene sulfonate After adding 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 material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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  4

In the polymerization reactor, a monomer mixture consisting of 29% by weight of acrylonitrile, 65% by weight of 1,4-butadiene and 4% by weight of methacrylic acid, 0.6 part by weight of t-dodecyl mercaptan, and 2 parts by weight of sodium dodecylbenzene sulfonate After adding 0.3 parts by weight of potassium persulfate and 140 parts by weight of water, polymerization was started at a temperature of 35 ° C.

2 weight% of methacrylic acid was added at the time of 60% of the polymerization conversion rate.

Next, when the polymerization conversion reached 94%, 0.3 parts by weight of ammonium hydroxide was added to terminate the polymerization. Thereafter, the unreacted material was removed through a deodorizing process, and ammonia water, an antioxidant, and an antifoam were added to obtain a carboxylic acid-modified nitrile copolymer latex 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.

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

1. Measurement of carboxylic acid-modified nitrile copolymer latex properties

The physical properties of the carboxylic acid-modified nitrile copolymer latex prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 1 below.

(Capillary Viscosity Measurement)

The latex obtained by polymerization was dissolved in MEK at a concentration of 0.027 wt% to ensure good dispersion. 10 ml of this solution was placed in a Cannon-Fenske routine type capillary viscometer, and the viscosity was calculated by measuring the time taken to pass the capillary at 25 ° C. The equation for obtaining the viscosity using time is as follows.

ν = k

k is the constant of the capillary and t is the time taken to pass through the capillary.

(MEK insoluble)

After polymerizing the latex obtained by drying in a constant temperature and humidity room for 48 hours, 0.3g, 80 Mesh was added to the MEK 100ml and left for 48 hours at room temperature. Thereafter, the weight of the remaining film was obtained by drying.

MEK insoluble (%) = (film weight after drying) / 0.3 X 100 (%)

(Molecular weight of sol)

After polymerizing the latex obtained by drying in a constant temperature and humidity room (25 ℃, 50% humidity) for 48 hours, the film was dissolved in THF, and only the sol portion dissolved in the solvent was taken into water (PCS 2414 Refractive Index Detector with external column heater, Waters 1515 Isocractic). The molecular weight was measured using a Pump, Waters 717Plus Autosampler).

(Ethylenically unsaturated acid monomer content bound to the copolymer, AA content)

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, and the obtained diluted solution was cooled to room temperature, and then the pH was dropped 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, and the obtained diluted solution was cooled to room temperature, and titrated with an accurate 3% potassium hydroxide aqueous solution to calculate the amount of bound acid.

(Ethylenically unsaturated nitrile monomer content, AN content bound to the copolymer)

The latex obtained by polymerization was dried at 130 ° C. for 40 minutes, and then the content of bound nitrile monomer was calculated using an element analyzer.

2. Measurement of properties of dip molded products

The physical properties of the dip molded products prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 1 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. Subsequently, the test piece was pulled at an elongation rate of 500 mm / min, and the stress at 300% elongation, the tensile strength at break and the elongation at break were measured.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Copolymer latex Capillary Viscosity (mm ² / s) 7.1 6.3 6.8 6.5 5.5 3.2 8.2 5.9 MEK insoluble (%) 0 0 6 5 15 45 10 5 Sol Part Molecular Weight 220,000 200,000 230,000 210,000 180,000 120,000 160,000 180,000 AA content (% by weight) 5.8 5.9 5.4 5.2 5.8 5.8 3.0 4.8 AN content (% by weight) 28 29 27 30 29 29 20 29 Thickness (mm) 0.057 0.056 0.056 0.058 0.057 0.054 0.060 0.058 Tensile Strength (N) 6.3 6.2 6.4 6.4 5.8 4.8 4.0 5.4 Dip molding % Elongation 545 517 564 540 525 480 430 543
300% modulus (MPa) 8.0 8.8 7.7 7.9 7.6 8.0 5.0 6.2

Referring to Table 1, when the molecular weight modifier is added in consideration of the polymerization conversion rate as in Examples 1 to 4, the molecular weight is increased and the MEK insoluble content is low. It can be seen that.

In comparison with the same composition, it can be seen that the physical properties of latex and dip molded articles of Comparative Examples 1 to 3 to which the molecular weight modifier was added from the beginning are lower than those of Examples 1 to 3.

Furthermore, in the case of Comparative Example 4, when the monomers other than the molecular weight modifier were added at the time when the polymerization conversion rate was 60% or more, the tensile strength, elongation and modulus of the dip molded products increased slightly, but the dip molded products of Examples 1 to 4 It was still low compared to.

The carboxylic acid-modified nitrile copolymer latex 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 through a dip molding process.

Claims (19)

delete delete delete delete delete In the method for emulsion-polymerizing conjugated diene monomer, ethylenically unsaturated nitrile monomer and ethylenically unsaturated acid monomer to prepare a carboxylic acid-modified nitrile copolymer latex,
0.2 part by weight to 100 parts by weight of the conjugated diene monomer, the ethylenically unsaturated nitrile monomer and the ethylenically unsaturated acid monomer mixture at a time when the polymerization conversion rate is 60% or more and 70% or less after the progress of polymerization. A method for producing a carboxylic acid-modified nitrile copolymer latex, characterized in that the reaction at 0.5 parts by weight. The method of claim 6,
After the addition of the molecular weight regulator, a method for producing a carboxylic acid-modified nitrile copolymer latex, characterized in that 20% by weight or less of the total amount of the monomer, emulsifier and initiator is added at a polymerization conversion rate of 60% or more. The method of claim 6,
Method of producing a carboxylic acid-modified nitrile copolymer latex, characterized in that the addition of one or more selected from the group consisting of monomers, emulsifiers, initiators, and combinations thereof simultaneously or after the addition of the molecular weight regulator. The method of claim 8,
When the addition, at least one selected from the group consisting of monomers, emulsifiers, initiators, and combinations thereof, the carboxylic acid-modified nitrile copolymer latex, characterized in that the addition is completed before the polymerization conversion rate of 85% after the progress of the polymerization Manufacturing method. The method of claim 8,
At the time of further addition, the method of producing a carboxylic acid-modified nitrile copolymer latex, characterized in that the one selected from the group consisting of monomers, emulsifiers, initiators, and combinations thereof are introduced into the reactor all at once or continuously. As a carboxylic acid modified nitrile copolymer latex manufactured by the method of manufacturing the carboxylic acid modified nitrile copolymer latex of Claim 6,
The carboxylic acid-modified nitrile copolymer latex has a capillary viscosity of 6.0 mm ² / s or more, an amount of MEK insoluble content of 10% or less, a sol partial molecular weight of 180,000 or more, and is bonded to the copolymer A carboxylic acid-modified nitrile copolymer latex, characterized in that the amount of the ethylenically unsaturated acid monomer is 5.0 to 7.0% by weight and the amount of ethylenically unsaturated nitrile monomer bonded to the copolymer is 26 to 35% by weight. The method of claim 11,
The carboxylic acid-modified nitrile copolymer is a polymerization of a monomer mixture comprising 40 to 75% by weight of conjugated diene monomer, 25 to 40% by weight ethylenically unsaturated nitrile monomer and 4 to 8% by weight ethylenically unsaturated acid monomer Carbonic acid modified nitrile copolymer latex characterized by the above-mentioned. The method of claim 12,
The conjugated diene monomer is a group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene, isoprene, and combinations thereof Carboxylic acid-modified nitrile copolymer latex comprising one selected from. The method of claim 12,
The ethylenically unsaturated nitrile-based monomer is characterized in that it comprises one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile, α-cyano ethyl acrylonitrile, and combinations thereof. Carboxylic acid modified nitrile copolymer latex. The method of claim 12,
The ethylenically unsaturated acid monomers are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, citraconic anhydride, styrene sulfonic acid, monobutyl fumarate, monobutyl maleic acid, mono-2-hydroxypropyl maleate, and A carboxylic acid-modified nitrile copolymer latex comprising one selected from the group consisting of a combination of these. A latex composition for dip molding comprising the carboxylic acid-modified nitrile copolymer latex according to any one of claims 11 to 15. A dip molded article prepared by dip molding with the latex composition for dip molding according to claim 16. The method of claim 17,
The dip molded article is a dip molded article, characterized in that the household gloves, industrial gloves, medical gloves, condoms or catheter. (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 crosslinked dip molding layer from the mold to obtain a dip molded article; Including but not limited to:
The dip molding latex composition is a dip-molded article manufacturing method comprising a carboxylic acid-modified nitrile copolymer latex of any one of claims 11 to 15.