KR-20260062507-A - COMPOSITION OF LATEX FOR DIP MOLDING WITH EXCELLENT CHEMICAL RESISTANCE AND DIP MOLDED ARTICLE PREPARED THEREFROM

Abstract

The present specification provides a latex composition for dip molding comprising a copolymer latex polymerized from an ethylene unsaturated nitrile monomer, an isoprene monomer, a butadiene monomer, and an ethylene unsaturated acid monomer, wherein the content of the butadiene monomer is 5 to 20 parts by weight based on 100 parts by weight of the total isoprene monomer and butadiene monomer, and the gel content of the copolymer latex is 40 to 90%.

Inventors

• 전종진
• 정성훈

Assignees

• 금호석유화학 주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (8)

1. A latex composition for dip molding comprising a copolymer latex polymerized from an ethylenically unsaturated nitrile monomer, an isoprene monomer, a butadiene monomer, and an ethylenically unsaturated acid monomer, wherein The content of the butadiene monomer is 5 to 20 parts by weight based on 100 parts by weight of the total isoprene monomer and butadiene monomer, and The gel content of the above copolymer latex is 40 to 90%, Latex composition for dip molding.
2. In paragraph 1, A latex composition for dip molding, wherein the above-mentioned ethylenically unsaturated nitrile monomer is one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile, α-cyanoethylacrylonitrile, and combinations of two or more of these.
3. In paragraph 1, A latex composition for dip molding, wherein the above-mentioned ethylenically unsaturated acid monomer is one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, citraconic anhydride, styrene sulfonic acid, monobutyl fumarate, monobutyl maleate, mono-2-hydroxypropyl maleate, and combinations of two or more of these.
4. In paragraph 1, The copolymer latex comprises 1 to 55 parts by weight of the ethylenically unsaturated nitrile monomer, 65 to 80 parts by weight of the isoprene monomer, 1 to 10 parts by weight of the butadiene monomer, and 1.5 to 6.0 parts by weight of the ethylenically unsaturated acid monomer, forming a latex composition for dip molding.
5. In paragraph 1, A dip-molding latex composition having a deformation rate represented by the following Formula 1 of a dip-molding article manufactured from the above dip-molding latex composition of 50% or less: [Equation 1] (Strain) = (ab)/a*100. (In Equation 1, a represents the weight (g) measured after manufacturing a dip-molded product with a width of 30 mm, a length of 135 mm, and a thickness of 0.06 to 0.09 mm, and b represents the weight (g) measured after immersing the manufactured dip-molded product in 80 ml of solvent and stirring at room temperature for 4 hours.)
6. In paragraph 5, A latex composition for dip molding, wherein the solvent is one selected from the group consisting of acetone, ethanol, isopropyl alcohol, methyl ethyl ketone, n-heptane, and toluene.
7. A dip-molded article manufactured from a dip-molding latex composition of any one of claims 1 to 6.
8. In Paragraph 7, The above dip-molded article is a surgical glove, medical glove, glove for agricultural product processing, industrial glove, condom, cosmetic material, catheter, or healthcare molded article.

Description

Composition of latex for dip molding with excellent chemical resistance and dip-molded article prepared therefrom The present specification relates to a latex composition for dip molding with excellent chemical resistance and a dip-molded article made therefrom. Traditionally, the primary raw material for gloves used in medical, agricultural and livestock processing, or industrial applications was natural rubber latex. However, when using gloves made from natural rubber latex, the problem of users suffering from contact allergic diseases due to the proteins contained in the natural rubber latex occurred frequently. Consequently, attempts were made to manufacture gloves using synthetic rubber latex that does not contain proteins, such as nitrile copolymer latex. Nitrile copolymer latex gloves have superior mechanical strength compared to natural rubber latex gloves, leading to an increasing demand in the medical and food sectors where contact with sharp objects occurs frequently. With the increasing use of nitrile copolymer latex, there is a growing need to improve the quality of dip-molded products, and accordingly, attempts are being made to improve the durability, such as tensile strength and elongation, of dip-molded products manufactured from dip-molded latex. However, despite these attempts to improve mechanical properties, there are continuing cases where accidents resulting in injury or failure to achieve the desired purpose occur due to the breakage of dip-molded products. In particular, molded articles used for the purpose of protecting the human body from chemical reactions, etc., need to have chemical resistance that allows them to maintain their shape stably without deformation in various solvents such as organic solvents like acetone and n-hexane. There is a need for the development of technology to manufacture dip-molded articles that possess excellent durability and chemical resistance while maintaining the excellent tensile strength and elongation of existing nitrile-based latexes, while also having such chemical resistance. Hereinafter, one aspect of this specification will be described based on specific examples. However, the details described in this specification may be implemented in various different forms and are therefore not limited to the embodiments described herein. Throughout the specification, when it is stated that a part is "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components. When a range of numerical values is described in this specification, unless a specific range is otherwise described, the value has the precision of significant figures provided according to the standard rules in chemistry for significant figures. For example, 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49. Latex composition for dip molding A latex composition for dip molding according to one aspect of the present specification comprises a copolymer latex polymerized from an ethylenedimethyl unsaturated nitrile monomer, an isoprene monomer, a butadiene monomer, and an ethylenedimethyl unsaturated acid monomer. Among the copolymer latexes polymerized from conventionally used ethylenically unsaturated nitrile monomers, conjugated diene monomers, and ethylenically unsaturated acid monomers, the most widely known is nitrile-isoprene (NI) copolymer latex. Nitrile-isoprene copolymer latex exhibits high elongation and low modulus, resulting in excellent mechanical properties and high durability. However, this nitrile-isoprene copolymer latex is somewhat lacking in the chemical resistance required for use in latex gloves in laboratories involving chemical reactions, such as experiments. Chemical resistance refers to the characteristic of maintaining its shape and physical properties without dissolving or deforming in various organic solvents. After conducting repeated experiments to impart chemical resistance to existing nitrile-isoprene copolymer latex, the inventors confirmed that by utilizing butadiene together with isoprene as a conjugated diene monomer, a dip molding latex with a high gel content, excellent durability, and chemical resistance could be obtained, and thus completed the present invention. In the latex composition for dip molding of the present invention, the content of the butadiene monomer may be 5 to 20 parts by weight based on 100 parts by weight of the total sum of the isoprene monomer and the butadiene monomer, preferably 7 to 19.5 parts by weight, more preferably 8 to 19 parts by weight, even more preferably 10 to 18.5 parts by weight, and most preferably more than 10 parts by weight a