Latex composition for dip forming and dip-formed article prepared therefrom

Patent metadata

Field	Value
Publication number	US-10100179-B2
Application number	US-201515516727-A
Country	US
Kind code	B2
Filing date	Dec 23, 2015
Priority date	Dec 23, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

Provided is a latex composition for dip forming which includes 100 parts by weight of a nitrile-based hybrid latex including a first latex and a second latex which have different glass transition temperatures, and 2 parts by weight to 8 parts by weight of an ion-conductive polymer having a weight-average molecular weight of 400 to 1,000. The latex composition for dip forming has excellent low-temperature stability and a dip-formed article prepared using the composition has excellent tensile strength and elongation. Since wearing comfort is improved due to a decrease in modulus, the dip-formed article may be suitable for industries requiring such properties.

First claim

The invention claimed is:

1. A latex composition for dip forming, the latex composition comprising:
100 parts by weight of a nitrile-based hybrid latex including a first latex and a second latex which have different glass transition temperatures; and
1 to 8 parts by weight of an ion-conductive polymer having a weight-average molecular weight of 400 to 1,000.

2. The latex composition for dip forming of claim 1 , wherein the first latex has a glass transition temperature of −50° C. to −25° C., and the second latex has a glass transition temperature of —25° C. to −15° C.

3. The latex composition for dip forming of claim 1 , wherein the first latex has an average particle diameter of 90 nm to 200 nm, and the second latex has an average particle diameter of 100 nm to 200 nm.

4. The latex composition for dip forming of claim 1 , wherein the hybrid latex comprises 30 wt % to 80 wt % of the first latex and 20 wt % to 70 wt % of the second latex.

5. The latex composition for dip forming of claim 1 , wherein the ion-conductive polymer has a weight-average molecular weight of 550 to 650.

6. The latex composition for dip forming of claim 1 , wherein the ion-conductive polymer comprises at least one selected from the group consisting of polyethylene glycol, polyethylene oxide, polypropylene glycol, and polyethylene glycol methacrylate.

7. The latex composition for dip forming of claim 1 , wherein the ion-conductive polymer is diluted in an aqueous solvent to a concentration of 5% to 20%.

8. The latex composition for dip forming of claim 1 , wherein the ion-conductive polymer has a glass transition temperature of −45° C. to −35° C.

9. The latex composition for dip forming of claim 1 , wherein the latex composition has a pH of 8 to 12.

10. The latex composition for dip forming of claim 1 , wherein the latex composition has a solid concentration of 10 wt % to 40 wt %.

11. The latex composition for dip forming of claim 1 , further comprising an additive,
wherein the additive comprises any one selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, an ionic cross-linking agent, a pigment, a filler, a thickener, a pH adjuster, and a combination thereof.

12. A dip-formed article prepared from the latex composition of claim 1 .

13. The dip-formed article of claim 12 , wherein the dip-formed article comprises any one selected from the group consisting of surgical gloves, examination gloves, condoms, catheters, industrial gloves, household gloves, health care products, and a combination thereof.

14. A method of preparing a latex composition for dip forming, the method comprising:
preparing each of a first latex and a second latex which have different glass transition temperatures;
mixing an ion-conductive polymer having a weight-average molecular weight of 400 to 1,000 with each of the first latex and the second latex to prepare a first latex composition and a second latex composition; and
blending the first latex composition and the second latex composition to prepare a nitrile-based hybrid latex composition, wherein the blending is performed to obtain 100 parts by weight of the nitrile-based hybrid latex and 1 part by weight to 8 parts by weight of the ion-conductive polymer having a weight-average molecular weight of 400 to 1,000.

15. The method of claim 14 , wherein the preparing of each of the first latex and the second latex comprises preparing a monomer mixture which includes 40 wt % to 89 wt % of a conjugated diene-based monomer, 10 wt % to 50 wt % of an ethylenically unsaturated nitrile-based monomer, and 0.1 wt % to 15 wt % of an ethylenically unsaturated monomer.

16. The method of claim 15 , wherein the preparing of each of the first latex and the second latex comprises adding one or more selected from a group consisting of an emulsifier, a chain transfer agent, a polymerization initiator, an auxiliary additive to the monomer mixture.

17. The method of claim 15 , wherein the preparing of each of the first latex and the second latex comprises performing a polymerization reaction of the monomer mixture,
wherein the polymerization reaction is performed in a temperature range of 10° C. to 90° C.

18. The method of claim 17 , wherein a conversion rate of the polymerization reaction is 90% or more.

19. The method of claim 14 , wherein the preparing of the hybrid latex composition comprises adding an additive to the hybrid latex composition,
wherein the additive comprises any one selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, an ionic cross-linking agent, a pigment, a filler, a thickener, and a combination thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Joe Won Tae
• Kim Hyun Woo
• Yeu Seung Uk
• Yang Seung Hun
• Kim Ji Hyun

Classifications

• C08L29/02

  Homopolymers or copolymers of unsaturated alcohols (C08L29/14 takes precedence) · CPC title

• C08L9/04 Primary

  Latex · CPC title

• C08J5/02 Primary

  Direct processing of dispersions, e.g. latex, to articles · CPC title

• B29C41/14

  Dipping a core {(B29C41/10 takes precedence)} · CPC title

• B29C41/00

  Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor (with compacting pressure B29C43/00 {; by lay-up of reinforcement of substantial or continuous length B29C70/30}) · CPC title