Search

CN-122011238-A - High-stability latex glove coagulant and preparation method and application thereof

CN122011238ACN 122011238 ACN122011238 ACN 122011238ACN-122011238-A

Abstract

The invention discloses a high-stability latex glove coagulant, and a preparation method and application thereof, and belongs to the technical field of polymer material processing aids. The coagulant comprises 12-18% of slow-release main gel, 1.5-2.5% of gradient release composite demolding/nucleating agent, 0.2-0.35% of rheology modifier, 0.35-0.55% of double-effect wetting spreading system, 0.3-0.6% of hydrolysis-resistant buffer system and the balance of deionized water. The main gel is modified calcium nitrate tetrahydrate, and the composite demolding/nucleating agent is a nano-scale composite micelle formed by high-speed shearing and emulsifying of sodium stearate, zinc stearate and calcium stearate. The invention realizes the chemical bonding of the coagulant with the hand mold and the latex layer through gradient release and interfacial chemical anchoring, remarkably improves the interlayer binding force, stability and demolding effect, and is suitable for dip molding of various latex gloves.

Inventors

  • LAN HUANGXIAN
  • LAN CHEN
  • YANG GUISHUANG
  • LI JINGFENG

Assignees

  • 桂林恒保健康防护有限公司

Dates

Publication Date
20260512
Application Date
20260330

Claims (7)

  1. 1. The high stability latex glove coagulant is characterized by comprising, by mass, 12% -18% of a slow release type main gel, 1.5% -2.5% of a gradient release type composite demolding/nucleating agent, 0.2% -0.35% of a rheology modifier, 0.35% -0.55% of a double-effect wetting spreading system, 0.3% -0.6% of a hydrolysis resistant buffer system, and the balance of deionized water/softened water with the conductivity of less than 10 mu S/cm; the slow-release main gel is calcium nitrate tetrahydrate with the modification rate of 5-8% and the jet milling to D90<20 mu m through methyl stearate grafting modification; the gradient release type composite demolding/nucleating agent is prepared by compounding sodium stearate, zinc stearate and calcium stearate, and performing high-speed shearing and emulsification for more than 30 minutes at 65-75 ℃ at 3000-5000rpm to form nanoscale composite micelles with the particle size D50 of less than 5 mu m, wherein the mass ratio of the sodium stearate to the zinc stearate to the calcium stearate is 1:1-1:3, and the ratio of the sodium stearate to the zinc stearate to the calcium stearate is (zinc stearate+calcium stearate) =1 (0.9-1.1); The rheology modifier is hydroxyethyl cellulose Ashland NatrosolTM 250 HHR; The double-effect wetting spreading system is formed by compounding 0.15-0.25% of low-foam alkyne diol surfactant TEGO cube Wet 500 and 0.2-0.3% of epoxy functional group polysiloxane coupling agent CoatOSil 1211; The hydrolysis-resistant buffer system is a mixture of glacial acetic acid and sodium acetate, and the pH value of the coagulant system is adjusted to 5.2-5.8.
  2. 2. The high stability latex glove coagulant according to claim 1, wherein the mass ratio of sodium stearate to the sum of zinc stearate and calcium stearate in the gradient release type composite mold release/nucleating agent is 1:1, and the mass ratio of zinc stearate to calcium stearate is 1:2.
  3. 3. The high stability latex glove coagulant according to claim 1, wherein the mass ratio of glacial acetic acid to sodium acetate in the hydrolysis resistant buffer system is 1 (1.2-1.5).
  4. 4. A method of preparing the high stability latex glove coagulant according to any one of claims 1 to 3, comprising the steps of: (1) The construction of nano micelle, namely adding zinc stearate, calcium stearate and part of sodium stearate into deionized water/softened water at 65-75 ℃ and shearing and dispersing at high speed of 3000-5000rpm for more than 30min to form stable semitransparent microemulsion with the particle size D50 of less than 5 mu m, namely gradient release type composite demolding/nucleating agent micelle liquid; (2) Swelling the gel system, namely adding modified calcium nitrate tetrahydrate and a rheology modifier into deionized water/softened water at 40-50 ℃, and stirring until the mixture is completely swelled to obtain a calcium nitrate/rheology modifier composite solution; (3) Slowly dripping the micelle liquid in the step (1) into the composite solution in the step (2), stirring at a constant temperature of 40-50 ℃ for 20-30 min, and inducing self-assembly by utilizing temperature difference and ionic strength; (4) The buffer system is regulated, namely an anti-hydrolysis buffer system is added into the mixed solution in the step (3), the mixture is stirred until uniform, and the pH value of the system is regulated to 5.2-5.8; (5) And (3) adding Wen Chuji, namely cooling the system in the step (4) to below 35 ℃, adding the double-effect wetting spreading system, stirring at a low speed for 10-15 min to be uniform, and adding deionized water/softened water until the total mass is 100%, thus obtaining the coagulant.
  5. 5. The preparation method of claim 4, wherein the addition amount of part of sodium stearate in the step (1) is 60% -70% of the total amount of sodium stearate, and the rest sodium stearate is synchronously added when the micelle liquid is dripped in the step (3).
  6. 6. The use of the high-stability latex glove coagulant according to any one of claims 1 to 3, wherein the coagulant is applied to a dip molding process of natural latex, nitrile latex or modified water-based high-end powder-free medical glove, thick-wall industrial glove and multi-layer composite protective glove, the temperature of a die is controlled to be 55-65 ℃, the dipping time is 8-12s, and the solid content of the latex is 40% -45%.
  7. 7. The use according to claim 6, wherein the coagulant comprises 16% of modified calcium nitrate tetrahydrate, 1:1 of zinc stearate and 0.5% of calcium stearate by mass, and the coagulant comprises 1211:0.3% of CoatOSil and 1:2 of zinc stearate by mass when used in a multilayer composite protective glove.

Description

High-stability latex glove coagulant and preparation method and application thereof Technical Field The invention belongs to the technical field of polymer material processing aids, and particularly relates to a high-stability latex glove coagulant based on gradient release type multi-element metal soap compounding and interfacial chemical anchoring, and a preparation method and application thereof. Background The dipping coagulant is a core auxiliary material for latex glove production, and has the core effects of forming a coagulant film on the surface of a hand mold, destroying the stability of latex through metal ions and promoting the uniform deposition and molding of rubber particles. At present, the traditional latex glove coagulant is mainly prepared by compounding single metal salts such as calcium nitrate and the like serving as main bodies with a small amount of thickener and wetting agent, and has a plurality of technical bottlenecks in actual production: The bonding force between layers is weak, namely the coagulant coating and the latex layer are bonded only by physical adsorption, and chemical bonding effect is avoided, so that the glove is easy to delaminate and fall off, and the problem is more remarkable particularly in the production of the multilayer composite glove. The system stability is poor, single metal soap is easy to agglomerate and precipitate in the system, the service life of the coagulant tank liquor is short, frequent replacement is needed, and the production cost and the production downtime are increased. When the single stearate is used as a separating agent, a good demolding effect and a latex vulcanization synergistic promotion effect cannot be simultaneously realized, the glove is easily damaged due to the fact that the demolding force is too high, and the mechanical properties of the glove are affected due to the fact that the vulcanization promotion is insufficient. The pH dependency is strong, the pH buffering capacity of the traditional coagulant is weak, alkaline substances brought in by latex in the production process easily cause system pH fluctuation, the gelation speed of calcium nitrate and uniformity of a gel film are affected, and the needle porosity of a product is increased. The wetting and spreading effects are poor, that is, only short-term surface tension reduction can be realized by a single wetting agent, and the flowing and uneven thickness of the coagulant are easy to occur, so that the defects on the surface of the glove are more. In order to solve the problems, simple compounding of the coagulant components is tried in the industry, but only certain performance can be singly improved, the improvement of the comprehensive performance of the system can not be realized, and the core problems of physical adsorption combination, gradient-free coagulation and the like are not fundamentally solved. Therefore, developing a latex glove coagulant which has high dispersion stability, strong interlayer binding force, excellent demolding and nucleation effects and is suitable for industrial mass production becomes a technical problem to be solved in the field. Disclosure of Invention Aiming at the technical defects of the existing latex glove coagulant, the invention provides the high-stability latex glove coagulant based on gradient release type multielement metal soap compounding and interfacial chemical anchoring, realizes the chemical anchoring combination of the coagulant with a hand mold and a latex layer, improves the storage and production stability of a system, and takes the synergistic effects of demolding, nucleation and vulcanization into consideration. In order to achieve the above purpose, the invention adopts the following technical scheme: The first aspect is a high stability latex glove coagulant, which comprises, by mass, 12% -18% of a slow release type main gel, 1.5% -2.5% of a gradient release type composite demoulding/nucleating agent, 0.2% -0.35% of a rheology modifier, 0.35% -0.55% of a double-effect wetting spreading system, 0.3% -0.6% of a hydrolysis resistant buffer system, and the balance of deionized water/softened water with conductivity less than 10 mu S/cm; The modified treatment of the slow-release main gel can prevent latex emulsion from being too fast due to too high local concentration, and the ultra-fine particle size promotes dispersibility, realizes slow release of gel ions and lays a foundation for gradient solidification; The gradient release type composite demolding/nucleating agent is prepared by compounding sodium stearate, zinc stearate and calcium stearate, and emulsifying for more than 30 minutes by high-speed shearing at 65-75 ℃ and 3000-5000rpm to form nanoscale composite micelles with the particle size D50 of <5 mu m, wherein the mass ratio of the sodium stearate to the zinc stearate is 1:1-1:3, the sodium stearate provides emulsifying dispersibility, the zinc stearate is taken as a quick nucleation point to rea