1. Uses
The agent is a white latex consisting of vinyl acetate, polyvinyl alcohol, dibutyl phthalate, octanol, and ammonium persulfate. It is widely used in wood, plywood, cement mortar, paper, cloth, leather, etc. The bonding, it is easy to use, strong adhesion, the production process is relatively simple. The disadvantage is poor performance at low temperatures.
2. Raw materials
( 1 ) Vinyl acetate: Also known as vinyl acetate, abbreviated as vinyl acetate, a colorless flammable liquid. Strong scent. Its vapor is irritating to the eyes. Insoluble in water, soluble in most organic solvents. Used to make vinyl esters and synthetic fibers. Also used to make rubber, paint, adhesives and so on. Used as a binder in this agent.
( 2 ) Polyvinyl alcohol: A macromolecular compound obtained by saponification of polyvinyl acetate. White or milky yellow powder. Thermoplastic. Depending on the degree of saponification, the product is soluble in water or can only swell. It is mainly used as a raw material for polyvinyl acetal resins, and also used as a binder, dispersant and the like. This agent is used as an adhesion aid. Use industrial products.
( 3 ) Dibutyl phthalate: Colorless liquid. Insoluble in water, soluble in organic solvents such as ethanol and ether. It is a plasticizer for making plastics, synthetic rubber, and artificial leather. It is also a fragrance solvent and curing agent. Used as a plasticizer in this agent. Use industrial products.
( 4 ) Octanol: Octanol has n-octanol and various isomers. This refers to 2 -ethylhexanol- 1 . Colorless liquid with special odor. Soluble in water and ethanol, ether and other organic solvents. This agent is used as a solvent. Use industrial products.
( 5 ) Ammonium persulfate: colorless monoclinic crystal. Sometimes light greenish, soluble in water. It is decomposed by heat and has strong oxidizing properties. Used as a bleach, oxidant, deodorant and so on. This agent is used as a polymerization initiator. Use industrial products.
3. Formula (weight%)
Vinyl acetate 45
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Polyvinyl alcohol 5
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Dibutyl phthalate 4
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Octanol 1
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Ammonium persulfate 0.1
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Water 44.9
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4. Preparation method
( 1 ) Mix dibutyl phthalate with octanol according to the formula and stir to dissolve it.
( 2 ) Add water to the vessel, heat to 70 °C, add polyvinyl alcohol with stirring, raise the temperature to 90 °C, and keep until all dissolved. After being dissolved, the heating was stopped to reduce the temperature to 66 to 69 °C, and vinyl acetate was added under stirring.
(3) The (1) was added the solution prepared in step (2) step was prepared, and finally ammonium persulfate was added, stirred and mixed uniformly, emulsion polymerization, to obtain white latex at 66 ~ 69 ℃.
5. How to use
Depending on the object to be bonded, the stock solution can be used as it is, or diluted appropriately. When diluting, warm up the emulsion to 30 ~ 40 °C first, and then slowly add distilled water at 30 ~ 40 °C. Do not dilute with cold water. Amount of water equivalent to the stock preferably 20 to 30%. If too much water is added, emulsifiability will be destroyed and failure will result. After dilution, starch paste and other thickening should be added.
When bonding wood, glue is generally applied on both adhesive surfaces and should be left open for a while after the glue is applied. Normally the amount of rubber to be applied is 100 grams per square meter, open for 5 minutes; when the amount of glue applied is 150 grams per square meter, open for 10 minutes; when the amount of rubber to be applied is 200 grams per square meter, open it for 20 minutes, and then paste , Place 20 minutes, and then press the pressure of 0. 294 ~ 0.490 MPa for more than 3 hours. It takes 8 to 16 hours to fully cure. Heat curing method can also be adopted. Generally, it is pressed at a pressure of 0.294 to 0.490 megapascals at 80 °C after the adhesive is allowed to dry until it is not adhered. The thin plate only needs to be pressed for several minutes, and the time for pressing the thick plate is appropriately extended.