It refers to any substance that can make high polymer rapidly solidify and agglomerate from latex;Gelling agent refers to the material that can gradually change the latex from liquid state to uniform semi-rigid solid gel.And heat sensitive agent is to point to after joining latex, after heating, can make the material of latex coagulation.
The coagulant is divided into internal coagulant and external coagulant.The internal coagulant is inserted inside the clot.If latex silk is produced and carried, acetic acid or hydrochloric acid with a concentration of 25% to 30% is commonly used as a coagulant [acetic acid residue is small, but volatile odor is large, volatile odor of hydrochloric acid is small, but residual]. In addition, formic acid and lactic acid can also be used as an internal coagulant.External coagulants are mainly used for ion deposition, commonly used are bivalent or trivalent metal salts and organic amine salts, such as anhydrous calcium chloride, calcium nitrate, barium chloride [note: this product is toxic, the only advantage is good adhesion, gel semi-product is not easy to slip], cyclohexylamine acetate, etc.Used to produce all kinds of latex gloves, all kinds of weather balloons, festival balloons, rubber tubes, finger covers and medical and health products and rubber rings.In particular, cyclohexylamine acetate is an organic coagulant, the product is white crystal, acetic acid taste, soluble in water and alcohol.Used for impregnating products, can not be washed without affecting its physical and mechanical properties and aging resistance.Generally 10% methanol, ethanol with a mixture of use, if you want to improve the gelation effect, can add a small amount of glacial acetic acid.
Gelling agents are mostly used as sponges.Dengluopu foaming latex is most commonly used in the latex industry.Such as potassium silicon-fluoride, sodium silicon-fluoride, ammonium sulfate, ammonium chloride, zinc oxide, zinc chloride and so on.
Three, thermal sensitizer
1. Zinc amine complex.A thermal sensitizer commonly used in the latex industry.Zinc chloride was generally taken as complexing agent with ammonia.When the temperature rises to more than 50 c, the complex ions of zinc ammonium will decompose ammonia and eventually generate zinc ions, which will form insoluble soap with carboxylic acid anions in the latex and make the latex lose its stability, thus resulting in gelation.
2. Polyethylene methyl ether.The product is a non - ionic polymer, soluble in cold water, 34 to 35 degrees Celsius precipitation.It can stabilize latex at room temperature and coagulate latex at high temperature.When in use, latex must be ammonia, PH value control in 9 to 9.6, glue to add some pingping add "O", in the presence of zinc oxide, its thermal sensitivity effect is significant.
3. Polyether polyformalin dimethyl alcohol.Brown viscous liquid.Dissolves in cold water, water temperature is above 50 Celsius, do not dissolve instead.The turbidity point of 5% aqueous solution is 50 c, and the PH value of 15% aqueous solution is 2.Thermally sensitive high temperature, at 35 degrees Celsius, stable storage, generally prepared into 15% water solution for use, suitable for impregnating products.
4. Polypropylene glycol.A colorless liquid of low viscosity.Soluble in water, but insoluble in hot water.Prepare 25% to 50% water solution.When the PH value of latex is greater than 8.5, a certain amount of zinc oxide should be added.In addition, still have polyethylene glycol, trypsin, also can use as latex heat sensitive agent.Can choose according to actual need.Above 3 kinds of chemical substances, can make latex produce to go stabilizing effect, glue friends should treat respectively when using.