WO2014142425A1 - Latex composition for dip molding and molded product produced therefrom - Google Patents

Abstract

The present invention relates to a latex composition for dip molding comprising a carboxylic acid modified nitrile-based copolymer latex and starch, and a molded product produced thereby, and provides a dip molded product having slow syneresis, low stickiness, and excellent tensile strength by mixing and using a carboxylic acid modified nitrile-based copolymer latex and starch.

Description

Latex composition for dip molding and molded article prepared therefrom

The present invention relates to a latex composition for dip molding and a molded article prepared therefrom, and more particularly, by using a mixture of carboxylic acid-modified nitrile copolymer latex and starch in a dip molding operation, excellent workability, non-sticky and tensile It relates to a latex composition for dip molding capable of producing a molded article having excellent strength and a molded article prepared therefrom.

At present, efforts are being made by glove companies to reduce the weight of nitrile rubber gloves. In order to reduce the weight of the gloves, the gloves must be made thinner. In order to make the gloves thinner, the concentration of the latex composition must be lowered. Then, when the gloves film is formed, syneresis is severely generated and the pinholes are rapidly increased in the final gloves.

In addition, the stickiness of the manufactured gloves is severe and there is a problem that the tensile strength is lowered. Therefore, glove makers are focusing on carboxylic acid-modified nitrile latex, which does not cause severe syneresis even if the glove is made thin, and does not stick to the final glove and does not degrade the tensile strength. Carboxylic acid-modified nitrile latex has not yet emerged.

Accordingly, in the present invention, to solve the problems of the prior art as described above, an object of the present invention is a carboxylic acid-modified nitrile system that can produce a product with excellent synergy and less sticky than the existing dip molding, excellent tensile strength It is to provide a copolymer latex composition.

Another object of the present invention is to provide a molded article prepared from the carboxylic acid-modified nitrile copolymer latex composition.

The above object of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a latex composition for dip molding comprising a carboxylic acid-modified nitrile copolymer latex and starch.

The present invention has a viscosity of 300 cPs or less when 85 to 98% by weight of a carboxylic acid-modified nitrile copolymer latex having a glass transition temperature of -50 ° C to -15 ° C and an average particle diameter of 50 nm or more and a temperature of 50 ° C and a concentration of 30% by weight. By mixing the starch 2 to 15% by weight and including it in the latex composition for dip molding, it is possible to solve the above conventional techniques.

By producing a latex composition by mixing the carboxylic acid-modified nitrile copolymer latex and starch as in the present invention, it is possible to produce a molded article excellent in workability during the dip molding operation, gentle synergy and less stickiness and excellent tensile strength.

The carboxylic acid-modified nitrile copolymer latex composition for dip molding of the present invention is characterized by comprising a carboxylic acid-modified nitrile copolymer latex and starch.

The glass transition temperature of the carboxylic acid-modified nitrile copolymer latex is -50 ° C to -15 ° C.

As another example, the glass transition temperature of the carboxylic acid-modified nitrile copolymer latex may be -45 ℃ to -20 ℃, when in this range, excellent tensile strength, and does not cause cracks in the dip molded product.

In addition, the average particle diameter of the carboxylic acid-modified nitrile copolymer latex may be 50 nm or more.

As another example, the average particle diameter of the carboxylic acid-modified nitrile copolymer latex may be 50nm to 500nm, 50nm to 300nm or 60 to 200nm, the viscosity of the latex does not increase within this range to produce a latex at a high concentration And also the tensile strength does not decrease after glove manufacture.

The glass transition temperature and the average particle diameter of the latex are the glass transition temperature and the average particle diameter of the polymer included in the latex.

The average particle diameter is a weight average particle diameter.

In addition, the starch may have a viscosity of 300 cPs or less when the temperature is 50 ° C. and the aqueous solution concentration is 30 wt%.

The latex composition for dip molding according to the present invention may include, for example, 70:30 to 99.9: 0.1, 75:25 to 99: 1, 81:19 to 99: 1, or 98: of the carboxylic acid-modified nitrile copolymer latex. It may be included in a weight ratio of 2 to 85:15.

Improve synergy time within the above range The width is large, the stickiness of the dip molded product is less, and the tensile strength is also excellent.

In addition, the latex composition for dip molding comprising a carboxylic acid-modified nitrile copolymer latex according to the present invention is a vulcanizing agent, ionic crosslinking agent, pigment, vulcanization catalyst, filler, thickener and pH It may comprise one or more additives selected from the group consisting of regulators.

The dip molded article according to the present invention is also obtained by dip molding the latex composition for dip molding.

In another example, the dip molded article of the present invention is a latex is prepared by adding an emulsifier, a polymerization initiator, and a molecular weight regulator to each monomer constituting the latex, and the temperature is 70 to 90 ℃, or 75 through a separate route After preparing starch having a concentration of 20 to 40% by weight, or 25 to 35% by weight at -85 ° C, the latex and starch are mixed at a temperature of 40 to 60 ° C, or 45 to 55 ° C The composition is prepared and then dip molded to produce the final product.

Hereinafter, the latex, starch, mixed carboxylic acid-modified nitrile copolymer latex and latex composition used to obtain the dip molded product of the present invention will be described in detail.

1.Carboxylic Acid Modified Nitrile Copolymer Latex

Latex according to the present invention is prepared by emulsion polymerization by adding an emulsifier, a polymerization initiator, a molecular weight regulator, and other additives to each monomer constituting the carboxylic acid-modified nitrile copolymer.

Monomers constituting the carboxylic acid-modified nitrile copolymer are, for example, conjugated diene monomers, ethylenically unsaturated nitrile monomers, and ethylenically unsaturated acid monomers.

The carboxylic acid-modified nitrile copolymer may further include, for example, an unsaturated ethylenic monomer copolymerizable with the monomers.

Specific examples of the conjugated diene monomer constituting the carboxylic acid-modified nitrile copolymer according to the present invention include 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3- Butadiene, 1,3-pentadiene and isoprene selected from the group consisting of 1,3-butadiene and isoprene, and among these, 1,3-butadiene is most preferably used.

The conjugated diene monomer is included in 40 to 89% by weight, 45 to 80% by weight, or 50 to 78% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer, for example. Within this range, the dip molded product is flexible and comfortable to wear, and the dip molded article is excellent in oil resistance and tensile strength.

As another monomer constituting the carboxylic acid-modified nitrile copolymer 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 ronitrile, of which acrylonitrile and methacrylonitrile are preferred, and acrylonitrile is most preferably used.

The ethylenically unsaturated nitrile monomer is included in 10 to 50% by weight, 15 to 45% by weight, or 20 to 40% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer, for example. Within this range, the dip molded article is excellent in oil resistance and tensile strength, and the dip molded article is flexible and comfortable to wear.

As another monomer constituting the carboxylic acid-modified nitrile copolymer according to the present invention, the ethylenically unsaturated acid monomer is an ethylenically unsaturated monomer containing at least one acidic group selected from the group consisting of carboxyl group, sulfonic acid group and acid anhydride group, 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; And ethylenically unsaturated polycarboxylic acid partial ester monomers such as monobutyl fumarate, monobutyl maleate, and mono-2-hydroxypropyl maleate. Of these, methacrylic acid is particularly preferable. Such ethylenically unsaturated acid monomers may be used in the form of alkali metal salts or ammonium salts.

The ethylenic unsaturated acid monomer is included in 0.1 to 10% by weight, 0.5 to 9% by weight, or 1 to 8% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer, for example. Within this range, the dip molded article is excellent in tensile strength, and the dip molded article is flexible and comfortable to wear.

The carboxylic acid-modified nitrile copolymer according to the present invention may further include other ethylenically unsaturated monomers that can be optionally copolymerized with the above monomers, for example, 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 and 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, (meth) acrylic acid 1-cyanopropyl, (meth) acrylic acid 2-ethyl-6-cyanohexyl, (meth) acrylic acid 3-cyanopropyl, (meth) acrylic acid hydroxyethyl, (meth) acrylic acid hydroxy And at least one member selected from the group consisting of ethylenically unsaturated carboxylic acid ester monomers selected from the group consisting of propyl, glycidyl (meth) acrylate, and dimethylamino ethyl (meth) acrylate.

The amount of the copolymerizable other ethylenically unsaturated monomer may be used, for example, in 20% by weight, or 0.01 to 20% by weight of the total monomers constituting the carboxylic acid-modified nitrile copolymer. Within this range there is a balance between a soft fit and tensile strength.

As another example, the carboxylic acid-modified nitrile copolymer latex of the present invention may be prepared by emulsion polymerization by adding an emulsifier, a polymerization initiator, an activator, a molecular weight modifier, and the like to the monomer constituting the carboxylic acid-modified nitrile copolymer. have.

Although it does not specifically limit as an emulsifier, For example, anionic surfactant, a nonionic surfactant, cationic surfactant, an amphoteric surfactant, etc. 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 usage-amount of an emulsifier is 0.3-10 weight part, 0.8-8 weight part, or 1.5-6 weight part with respect to 100 weight part of monomers which comprise the said carboxylic acid modified nitrile copolymer, for example.

If the amount of the emulsifier is less than 0.3 parts by weight, the stability during the polymerization is lowered, if it exceeds 10 parts by weight, there is a problem that the production of dip molded article is difficult to increase the foaming.

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 persulfate can be used especially preferably.

The usage-amount of a polymerization initiator is 0.01-2 weight part, 0.02-1.5 weight part, or 0.05-1.0 weight part with respect to 100 weight part of all monomers which comprise the said carboxylic acid modified nitrile copolymer, for example. Within this range, the rate of polymerization can be controlled to easily produce the final product and the polymerization stability is also excellent.

The activator may be at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrroline and sodium sulfite.

Although it does not specifically limit as said 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 diisopropylquixanthogen disulfide. 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. The usage-amount of a molecular weight modifier is 0.1-2.0 weight part, 0.2-1.5 weight part, or 0.3-1.0 weight part with respect to 100 weight part of all monomers which comprise the said carboxylic acid modified nitrile copolymer, for example. Within this range, there is an effect that the physical properties and polymerization stability of the dip molded article are remarkably improved.

In addition, during the polymerization of the latex of the present invention, if necessary, additional materials such as chelating agent, dispersing agent, pH adjusting agent, deoxygenating agent, particle size adjusting agent, anti-aging agent, oxygen scavenger and the like can be added.

The method of adding the monomer mixture constituting the carboxylic acid-modified nitrile copolymer may be, for example, a method of introducing the monomer mixture into the polymerization reactor at once, a method of continuously adding the monomer mixture into the polymerization reactor, or a portion of the monomer mixture into the polymerization reactor. And the remaining monomers are continuously supplied to the polymerization reactor.

Although the polymerization temperature at the time of the said emulsion polymerization is not specifically limited, For example, they are 10-90 degreeC, 20-80 degreeC, or 25-75 degreeC.

The conversion rate at the time of stopping a polymerization reaction is 90% or more, 90%-99.9%, or 93%-99%, for example.

The carboxylic acid-modified nitrile copolymer latex can be obtained by removing the unreacted monomer and adjusting the solid content concentration and pH.

The glass transition temperature can be adjusted according to the content of the conjugated diene monomer, and the average particle size and particle size distribution can be adjusted according to the type or content of the emulsifier.

The latex glass transition temperature was measured by differential scanning calorimetry, and the average particle diameter was measured by a laser scattering analyzer (Nicomp).

For example, the carboxylic acid-modified nitrile copolymer latex may have a solid content (concentration) of 20 to 70 wt%, 30 to 60 wt%, or 40 to 50 wt%.

2. starch

Starch according to the present invention can be used for all commercially available products, for example, when the temperature is 50 ℃ and the aqueous solution concentration is 30% by weight may be a viscosity of 300 cPs or less. For example, the viscosity may be a Brookfield viscometer.

The starch is, for example, a mixture of amylose and amylopectin, and in another example, a mixture including 0 to 40% by weight of amylose and 60 to 100% by weight of amylopectin, or 10 to 30% by weight of amylose and 70 to amylotectin. It may be a mixture consisting of 90% by weight.

As another example, the viscosity of the starch may be 10 cPs to 300 cPs when the temperature is 50 ° C. and the concentration is 30 wt%. When the viscosity of the starch is 300 cPs or less, the viscosity does not increase even after mixing with the latex, making it easy to manufacture a dip molded article.

The starch may be, for example, a starch solution or a starch suspension.

The starch solution may be, for example, an aqueous starch solution.

The starch suspension may be, for example, a suspension of starch dispersed in water.

The starch solution or starch suspension may, for example, have a concentration of 0.1 to 60% by weight, 1 to 55% by weight, 10 to 45% by weight, or 20 to 40% by weight, within which the synergy is gentle and sticky. Less blurring and excellent tensile strength.

The starch may be, for example, starch extracted from various grains such as rice, barley, corn, potato, sweet potato, and tapioca.

3. Latex Composition for Dip Molding

For example, in a mixture of latex and starch obtained by the above method, a vulcanizing agent, an ionic crosslinking agent, a pigment such as titanium oxide, a vulcanizing catalyst, a filler such as silica, a thickener and a pH adjusting agent such as ammonia or alkali hydroxide One or more additives selected from may be included to prepare a latex composition for dip molding according to the present disclosure.

The carboxylic acid-modified nitrile copolymer latex in the composition is one of the glove physical properties of the dip molded article of the present invention, for example, contained in the composition 80-99% by weight, 85-98% by weight, or 88-97% by weight Preferred at

Solid content concentration of the latex composition for dip molding of this invention is 5-40 weight%, 8-35 weight%, or 10-33 weight% as an example. PH of the latex composition for dip molding of this invention is 8.0-12, 9-11, or 9.3-10.5 as an example.

4. Dip Molded Products

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, an anode adhesion dipping method is preferable because of the advantage that a dip molded article having a uniform thickness can be easily obtained. The dip molded article may be a surgical glove, an inspection glove, a condom, a catheter, an industrial glove, a household glove or a health care product.

Hereinafter, the method for producing a dip molded article using the latex composition of the present invention will be described in detail step by step.

(a) dipping the hand-shaped dip mold into the coagulant solution to attach the coagulant to the surface of the dip mold;

Examples of 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 75% by weight, or 8 to 55% by weight.

(b) dipping the coagulant-coated dip molding mold into the latex irradiating composition of the present invention to form a dip molding layer

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

(c) cross-linking the latex resin by heating the dip molding layer formed on the dip molding die;

The syneresis time in the heat treatment can be measured by measuring, for example, the time that the water component falls from the dip mold. Dropping the water droplets within 1 minute may cause contamination of the dip molding composition in the field process, so it is preferable that the water droplets do not fall within 1 minute.

In the heat treatment, the water component evaporates first and curing through crosslinking is performed. Subsequently, the crosslinked dip molding layer is peeled off from the dip mold to obtain a dip molded article. When peeling off the dip molded product, stickiness can be expressed by the ten-point method as a hand feel. Ten points are the least sticky and easily peeled off the dip mold, and one point means a lot of stickiness cannot be peeled off from the dip mold.

(d) measuring the physical properties of the obtained dip molding

A dumbbell-shaped test piece can be produced from the obtained dip molded product in accordance with ASTM D-412. The specimen can then be pulled at a stretching rate of 500 mm / min using a universal testing machine (UTM) and the tensile strength at break can be measured.

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 1

Agitator, thermometer, cooler, nitrogen inlet and 10L high pressure reactor equipped with a monomer, emulsifier, and polymerization initiator are continuously replaced with nitrogen, and acrylonitrile 25% by weight, 1,3-butadiene 2.5 weight part of sodium alkyl benzene sulfonates, 0.5 weight part of t-dodecyl mercaptans, and 140 weight part of ion-exchange water were added with respect to 100 weight part of monomer mixtures of 70 weight% and 5 weight% of methacrylic acid, and it heated up to 40 degreeC.

After the temperature was raised, 0.25 parts by weight of potassium persulfate as a polymerization initiator was added, and when the conversion rate reached 95%, 0.1 parts by weight of sodium dimethyl dithio carbamate was added to terminate the polymerization. The unreacted monomer was removed through a deodorizing process, and ammonia water, an antioxidant, an antifoaming agent, and the like were added to obtain a carboxylated acrylonitrile-butadiene copolymer latex having a solid concentration of 45% and a pH of 8.5.

As a result of the analysis of the latex, the glass transition temperature is -40 ℃, the average particle diameter is shown to 130nm, and the latex prepared by the above is called 'latex-A'.

Next, starch (gencoat of Samyang Genex), which is widely used for paper coating on the market, was prepared at a temperature of 80 ° C. at a concentration of 30% by weight, and a viscosity of 252 cPs at a temperature of 50 ° C. The starch is called 'starch-A'.

A mixture was prepared by mixing Latex-A and Starch-A in 9: 1.

(Production of Dip Molding Composition)

A 3% potassium hydroxide solution and an appropriate amount of secondary distilled water were added to the mixture to obtain a dip molding composition having a solid concentration of 15% and a pH of 10.0.

(Dip molding product manufacturing)

A coagulant solution was prepared by mixing 12 parts by weight calcium nitrate, 87.5 parts by weight distilled water, and 0.5 parts by weight wetting agent (Teric 320 produced by Huntsman Corporation, Australia). The hand-shaped ceramic mold was immersed in this solution for 1 minute, taken out, and dried at 80 ° C. for 3 minutes to attach a coagulant to the hand-shaped mold.

Next, the mold to which the coagulant was applied was immersed in the dip molding composition for 1 minute, pulled up, dried at 120 ° C. for 4 minutes, and then soaked in water or hot water for 3 minutes. It was confirmed by the synergy time by checking the time of dropping water drops at 120 ℃ drying for 4 minutes. The mold was dried at 120 ° C. for 3 minutes and crosslinked at 130 ° C. for 20 minutes. Sticking was measured while peeling off the cross-linked dip molding layer from the hand-shaped mold to obtain a dip molded article in the form of a glove. The syneresis time, stickiness, and tensile strength are shown in Table 1 below.

Example 2

Agitator, thermometer, cooler, nitrogen gas inlet and 10L high pressure reactor equipped with a monomer, emulsifier, and polymerization initiator can be continuously added with nitrogen, and then acrylonitrile 35% by weight, 1,4-butadiene 60 3 parts by weight of sodium alkyl benzene sulfonate, 0.5 parts by weight of t-dodecyl mercaptan and 140 parts by weight of ion-exchanged water were added to 100 parts by weight of the monomer mixture of 5% by weight and methacrylic acid, and the temperature was raised to 40 ° C.

After the temperature was raised, 0.3 parts by weight of potassium persulfate as a polymerization initiator was added, and when the conversion rate reached 95%, 0.1 parts by weight of sodium dimethyl dithio carbamate was added to terminate the polymerization. The unreacted monomer was removed through a deodorizing process, and ammonia water, an antioxidant, an antifoaming agent, and the like were added to obtain a carboxylated acrylonitrile-butadiene copolymer latex having a solid concentration of 45% and a pH of 8.5.

As a result of the analysis of the latex, the glass transition temperature is -23 ℃, the average particle diameter is shown to 130nm, and from now on the latex produced by the above is called 'latex-B'.

Next, starch (Ecosynthetics Ecosphere) having low viscosity at high concentration was prepared at a concentration of 30% by weight, and the viscosity was 35 cPs at 50 ° C. The starch is called 'starch-B'.

A mixture was prepared by mixing latex-B and starch-B in a weight ratio of 9: 1.

Dip molded article was prepared in the same manner as in Example 1 and the physical properties are shown in Table 1 below.

Example 3

Except for mixing the latex-A and starch-A in Example 1 in a weight ratio of 98: 2 was prepared in the same manner as in Example 1, a dip molded article in the form of a glove, the physical properties are shown in Table 1 below.

Example 4

Except for mixing the latex-A and starch-A in Example 1 in a weight ratio of 85:15 to prepare a dip molded article in the form of a glove in the same manner as in Example 1, the physical properties are shown in Table 1 below.

Example 5

Except for mixing the latex-A and starch-B in Example 1 in a weight ratio 9: 1 was prepared in the same manner as in Example 1, a dip molded article in the form of a glove, the physical properties are shown in Table 1 below.

Example 6

Except for mixing the latex-B and starch-A in Example 1 in a weight ratio 9: 1 was prepared in the same manner as in Example 1, a dip molded article in the form of a glove, the physical properties are shown in Table 1 below.

Example 7

Except for mixing the latex-A and starch-A in Example 1 in a weight ratio of 8: 2, a dip molded article was prepared in the same manner as in Example 1, the physical properties are shown in Table 1 below.

Example 8

Except for mixing the latex-B and starch-B in Example 1 in a weight ratio of 8: 2 was prepared in the same manner as in Example 1 glove-shaped dip molded article, the physical properties are shown in Table 1 below.

Comparative Example 1

Except that the latex-A alone in Example 1 was prepared in the same manner as in Example 1 glove-shaped dip molded article, the physical properties are shown in Table 1 below.

Comparative Example 2

Except that the latex-B alone in Example 1 was prepared in the same manner as in Example 1 glove-shaped dip molded article, the physical properties are shown in Table 1 below.

Table 1

	Syneresis (Sec.)	Stickiness (10 points method)	Tensile strength (MPa)
Example 1	183	8	27.1
Example 2	128	9	33.1
Example 3	95	7	24.7
Example 4	> 240	10	25.0
Example 5	154	9	28.4
Example 6	121	9	33.9
Example 7	> 240	10	19.5
Example 8	> 240	10	21.3
Comparative Example 1	41	3	25.3
Comparative Example 2	55	2	32.2

As shown in the results of Table 1, a dip molded article (Examples 1 to 8) made of a carboxylic acid-modified nitrile-based latex mixed with carboxylic acid-modified nitrile-based latex and starch according to the present disclosure was prepared in Comparative Examples 1 to 2 Compared to the dip molded products, the syneresis was gentle, the stickiness was low, and the tensile strength was excellent.

Claims (12)

1. Carboxylic acid-modified nitrile copolymer latex; And

   Starch; latex composition for dip molding comprising a.
2. The method of claim 1,

   The carboxylic acid-modified nitrile copolymer latex has a glass transition temperature of -50 ° C to -15 ° C and an average particle diameter of 50 nm or more.
3. The method of claim 1,

   The starch is a dip molding latex composition, characterized in that the starch solution or starch suspension.
4. The method of claim 1,

   The starch is a latex composition for dip molding, characterized in that the viscosity is 300 cPs or less when the temperature is 50 ℃, aqueous solution concentration 30% by weight.
5. The method of claim 1,

   The latex composition for dip molding comprising the carboxylic acid-modified nitrile copolymer latex and the starch in a weight ratio of 70:30 to 99.9: 0.1.
6. The method of claim 1,

   The carboxylic acid-modified nitrile copolymer is characterized in that the monomer mixture comprising 40 to 89% by weight conjugated diene monomer, 10 to 50% by weight ethylenically unsaturated nitrile monomer and 0.1 to 10% by weight ethylenically unsaturated acid monomer is polymerized A latex composition for dip molding.
7. The method of claim 6,

   The conjugated diene monomer is 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 Dip molding latex composition, characterized in that the.
8. The method of claim 6,

   The ethylenically unsaturated nitrile-based monomer is for dip molding, characterized in that at least one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile and α-cyano ethyl acrylonitrile Latex composition.
9. The method of claim 6,

   The ethylenically unsaturated acid monomer is composed of acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, citraconic anhydride, styrene sulfonic acid, monobutyl fumarate, monobutyl maleic acid and mono-2-hydroxypropyl maleic acid. Dip molding latex composition, characterized in that at least one selected from the group.
10. The method of claim 1,

    The composition is a latex composition for dip molding further comprising at least one additive selected from the group consisting of vulcanizing agents, ionic crosslinking agents, pigments, vulcanization catalysts, fillers, thickeners and pH adjusting agents.
11. A dip molded article prepared by dip molding the latex composition for dip molding according to any one of claims 1 to 10.
12. a) applying a coagulant solution to the mold and drying; b) applying a latex composition for dip molding to a mold to which a coagulant is applied to form a dip molding layer; 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.

    The latex composition for dip molding is characterized in that it comprises a carboxylic acid-modified nitrile copolymer latex and starch

    Method for producing a dip molded article.