CN104231977A - Method for producing white latex - Google Patents

Abstract

The invention provides a method for producing a white latex, and belongs to the technical field of industrial adhesives. The method is implemented through the following technical scheme which comprises the following steps: dissolving polyvinyl alcohol powder in deionized water, completely filtering, adding into a reaction kettle, then adding an emulsifying agent, and stirring for uniformly mixing; adding a vinyl acetate monomer which accounts for 15% of total weight and potassium persulfate which accounts for 40% of formula content into a reaction kettle, continuing to stir, starting to increase temperature, and when the temperature is increased to 60-65 DEG C, stopping heating; adding an initiating agent when the vinyl acetate monomer is added, wherein the addition amount per hour accounts for 4.5% of the formula content, and the vinyl acetate and the initiating agent are completely added within 8 hours; adding cooling water to a clamping sleeve of the reaction kettle to control reaction temperature not to be higher than 80 DEG C; unclosing the cooling water to reduce the temperature inside the reaction kettle to be lower than 50 DEG C, adding a sodium bicarbonate water solution and dibutyl phthalate at the time, and regulating a pH value to 6-7; and continuously stirring in the reaction kettle all the time till the reaction kettle is cooled to room temperature so as to obtain a white latex finished product.

Description

The production method of white glue with vinyl

Technical field

The invention belongs to industrial adhesive techniques field, particularly relate to a kind of production method making white glue with vinyl.

Background technology

White glue with vinyl claims Polyvinyl acetate adhesive to be by acetic acid and ethylene synthase vinyl acetate between to for plastic.Normal temperature solidified, solidification is very fast, bonding strength is higher, adhesive linkage has good toughness and weather resistance and not easily aging.The shortcoming of polyvinyl acetate emulsion tamanori is that water tolerance and wet fastness are poor, easily moisture absorption in damp atmosphere, and at high temperature use can produce creep  makes Joint strength decline, and stores easy freezing  emulsion is damaged below-5 DEG C.

Summary of the invention

The invention provides a kind of production method of white glue with vinyl, realized by following technical proposals:

(1) pva powder is dissolved in deionized water filter completely, drop into reactor, then add emulsifying agent, stir and make it to mix;

(2) add in reactor by 15% of polyvinyl acetate (PVA) monomer total amount with 40% of Potassium Persulphate formula ratio, continue to stir and start to heat up, stop heating when temperature is raised to 60-65 DEG C;

(3) while adding Vinyl Acetate Monomer, also add initiator, add-on per hour is 4.5% of formula ratio, and vinyl acetate and initiator add in 8h, adds water coolant to control temperature of reaction not higher than 80 DEG C in reacting kettle jacketing;

(4) open water coolant, when reactor temperature is dropped to below 50 DEG C, add sodium bicarbonate aqueous solution and dibutyl phthalate, pH value is transferred to 6 ~ 7;

(5) stirring of reactor can not stop all the time, upon cooling to room temperature, obtains white glue with vinyl finished product.

Adopt the white glue with vinyl that the production method of white glue with vinyl of the present invention is obtained, appearance milky white foreign, the same with the using method of traditional polyvinyl acetate, freeze-thawing resistant, ageing-resistant, bonding strength is excellent, and the shelf lives is long.

Embodiment

Below by specific embodiment, the present invention is further illustrated.

White glue with vinyl raw material

1  vinyl acetate  has another name called vinyl acetate, and be called for short vinyl acetate between to for plastic, colourless flammable liquid, has intense flavors.Its steam is irritant to eye.Water insoluble, be dissolved in most of organic solvent.For Vinylester processed and synthon.Also for rubber processed, paint, tackiness agent etc.Tackiness agent is used as in this agent;

2  polyvinyl alcohol  are by the macromolecular compound of polyvinyl acetate (PVA) through saponification.White or milk yellow powder.Tool thermoplasticity.Different according to saponification degree, product water soluble or only can be swelling.The main raw material being used as polyvinyl acetal-based resin, is also used as tackiness agent, dispersion agent etc.Industrial goods are selected to be used as bonding agent in this agent;

3  dibutyl phthalate  colourless liquids.Water insoluble, be dissolved in the organic solvent such as ethanol, ether.Being softening agent when plastics processed, synthetic rubber, leatheroid etc., is also solvent and the solidifying agent of spices.In this agent, select industrial goods to be used as softening agent;

4  octanol  octanols have n-Octanol and various isomer, refer to 2-Ethylhexyl Alcohol-1 here, colourless liquid, have special odor, water-soluble with in the organic solvent such as ethanol, ether, select industrial goods to be used as solvent in this agent;

The colourless monoclinic crystal of 5  ammonium persulphate , sometimes slightly light green, water-soluble.Be heated, decompose, have strong oxidizing property.As SYNTHETIC OPTICAL WHITNER, oxygenant, deodorizing composition etc., industrial goods in this agent, are selected to be used as polymerization starter.

The each weight ratio of constituents of white glue with vinyl

Vinyl acetate 45: polyvinyl alcohol 5: dibutyl phthalate 4: octanol 1: ammonium persulphate 0.1: water 44.9.

Technical process

Pva powder dissolves and filters completely by 1  in deionized water, can select PVA-1788 2488 etc.;

Polyvinyl alcohol glue is dropped into stainless steel cauldron (also can use enamel reaction still, just the heat-transfer effect of enamel still is not as good as stainless steel cauldron) by 2 , then adds emulsifier op-10, starts stirrer, makes it to mix;

15% (namely 6.9) of polyvinyl acetate (PVA) monomer total amount and 40% (namely 0.036) of Potassium Persulphate formula ratio add in stainless steel cauldron by 3 , continue to stir and start to heat up.Heating is stopped when temperature is raised to 60-65 DEG C.Wherein it should be noted that initiator potassium persulfate should first add with the aqueous solution that pure water converts into 8% ~ 10% several times;

4  are under the effect of initiator, though stop heating temperature to raise voluntarily, when temperature is more than 65 DEG C, the reflux of reactor starts to occur backflow.Reflux when temperature is raised to more than 80 DEG C and weaken gradually.Now from the dropping bucket of reactor, carry out the dropping of polyvinyl acetate (PVA) monomer, rate of addition should control about 10% (namely about 4.6) in dropping total amount per hour.In reaction process, temperature of reaction be kept a close eye on, in reacting kettle jacketing, add water coolant to control temperature of reaction not higher than 80 DEG C;

5 , while adding Vinyl Acetate Monomer, also add initiator, and add-on per hour is about 4.5% of formula ratio;

6  vinyl acetates and initiator all should control to add at about 8h.Due to the effect of initiator, react after stronger  monomer adds, temperature of reaction can rise voluntarily, when rising to about 93 DEG C, and insulation 30min.Polyreaction completes substantially;

7  open water coolant, and temperature in stainless steel cauldron is reduced, and when dropping to below 50 DEG C, add sodium bicarbonate aqueous solution (should dissolve 10% concentration in advance) and dibutyl phthalate, pH value is transferred to till 6 ~ 7;

The stirrer of 8  stainless steel cauldrons can not stop all the time.Upon cooling to room temperature, obtain white glue with vinyl finished product, stop stirring  blowing, packaging;

9  when the viscosity of white glue with vinyl finished product is excessive, poor water resistance time  suitably can reduce the consumption of polyvinyl alcohol in formula;

If 10  white glue with vinyl stability of emulsion are poor, suitably can reduce the consumption of some initiators in formula,  can not be caused time very little and cause the polymerization of monomer difficulty;

11  dibutyl phthalate consumptions can not be too much, do not exceed 10% of monomer, otherwise the tackiness of white glue with vinyl finished product declines, and add cost.Its Main Function increases the toughness of emulsion and reduces the film-forming temperature of emulsion;

If the foam of 12  white glue with vinyl finished products is more, proper quantity of defoaming agent can be added;

The consumption of 13  initiator potassium persulfate and interpolation time should be noted grasping, and when starting to occur backflow, if quantity of reflux is large, show that initiator does not play a role, monomer is too much, should stop adding monomer, can increase some initiators as one sees fit, adds monomer again when refluxing normal;

14  are the emulsion liquid of white uniformity by the white glue with vinyl that above-mentioned white glue with vinyl formula and making method are produced, and solids content about 50%, pH value is about 5

In addition, this white glue with vinyl finished product also can add 801 glue, anatase thpe white powder produces modified latex.

Using method

The moisture rule of 1 timber should control at 8-15%, too highly too lowly can affect bonding quality;

2 pairs of substrate surfaces process, and make substrate surface without greasy dirt, dust and other impurity.Bonding plane must fully contact;

3 gluings should be evenly appropriate;

4 ambient temperature curables also heating curable, top temperature no more than 120 ° set time Yin Wendu different and different, can according to practical situation calmly;

During 5 pressurization, pressure wants enough, and pressurization is wanted evenly, should pressurize more than 1.5 hours, should display for some time after release.For reaching better bonding effect, preferably placing after release and processing again for 24 hours, within 72 hours, testing;

6 can use with some mixed with resin, as urea-formaldehyde resin, resol, melamine resin etc., to improve self not water tolerance and creep properties etc.

Claims (1)

1. a production method for white glue with vinyl, is characterized in that comprising the following steps:

(1) pva powder is dissolved in deionized water filter completely, drop into reactor, then add emulsifying agent, stir and make it to mix;

(2) add in reactor by 15% of polyvinyl acetate (PVA) monomer total amount with 40% of Potassium Persulphate formula ratio, continue to stir and start to heat up, stop heating when temperature is raised to 60-65 DEG C;

(3) while adding Vinyl Acetate Monomer, also add initiator, add-on per hour is 4.5% of formula ratio, and vinyl acetate and initiator add in 8h, adds water coolant to control temperature of reaction not higher than 80 DEG C in reacting kettle jacketing;

(4) open water coolant, when reactor temperature is dropped to below 50 DEG C, add sodium bicarbonate aqueous solution and dibutyl phthalate, pH value is transferred to 6 ~ 7;

(5) stirring of reactor can not stop all the time, upon cooling to room temperature, obtains white glue with vinyl finished product.