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Preparation method of a water-based polyacrylate block copolymer pressure sensitive adhesive 2

In this embodiment, the water-based polyacrylate block copolymer pressure sensitive adhesive, the pressure sensitive adhesive solid content of 60% is a water-based polyacrylate block copolymer, water-based polyacrylate block copolymer multi-block structure, including hard monomer: isobornyl acrylate 10kg, methyl methacrylate 12kg; Soft monomer: butyl acrylate 50kg, isooctyl acrylate 25kg; Functional monomer: hydroxyethyl methacrylate 1.5kg; Crosslinking monomer, N  hydroxymethyl acrylamide 1. 5 kg.

The preparation method of the above water-based polyacrylate block copolymer pressure sensitive adhesive includes the following steps:

S1, 0.8kg sodium dodecyl sulfate was dissolved in 66.67kg deionized water to obtain the aqueous phase, 0.08kg hexadecyl alcohol and 0.08kg trithiocarbonate (Z group is phenyl, the R group is nitrile-isopropyl) were dissolved in the soft monomer successively and added to the aqueous phase. After mixing evenly, the pH of the mixture was adjusted to 10. Then the mixture was dispersed ultrasonically for 20min to obtain the soft monomer pre-emulsification solution.

S2, add the soft monomer pre-emulsion into the reaction kettle, add 0.12kg dibenzoyl peroxide, stir evenly, and heat the reaction solution to 75℃ for polymerization reaction;

S3, after polymerization for 2 hours, hard monomers, functional monomers, and crosslinked monomers were added, stirred evenly and block copolymerization was initiated at 75℃. For S4, after copolymerization for 2h, 0.03kg azodicyanopentonic acid was added and kept at 80℃ for 2h before discharge, to obtain water-based polyacrylate block copolymer pressure sensitive adhesive. When using, the pressure sensitive adhesive emulsion is directly coated on the PET base film of 50μm, the thickness of the dry adhesive is 10μm, and the PET base film is placed in the oven at 125℃ for 3min.

A solvent-based conductive pressure-sensitive adhesive preparation method 3

(1) The expanded graphite was dispersed in an ethanol solution with 20 times the mass fraction of the expanded graphite, stirred at 200rpm for 12h, ultrasonic dispersed at 80kHz for 12h, filtered, and washed with deionized water until the lotion was neutral, and graphite sheets were obtained; The graphite sheet was mixed with sodium hydroxide solution with 10 times the mass fraction of the graphite sheet and 10% of the mass fraction. The graphite sheet was ultrasonically dispersed at 80kHz for 4h, and then the stannous chloride hydrochloric acid solution with 3 times the mass fraction of the graphite sheet was added.

After 1h reaction, Add palladium chloride hydrochloric acid solution (10% mass fraction of graphite sheet) and boric acid solution (0% mass fraction of graphite sheet), continue to react for 3h, filter, and wash with deionized water for 8 times, and transfer to silver ammonia solution (20% mass fraction of graphite sheet).

Formaldehyde solution with a mass fraction of 10% was added at 7ml/min below 100rpm while stirring, and the mass ratio of formaldehyde solution to silver ammonia solution was 5:1. After the drip was finished, it was left to stand for 8h, filtered, washed with deionized water for 5 times, and transferred to a drying oven and dried at 100℃ for 6h to prepare silver-plated nano graphite sheets. Butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, acrylic acid, methyl methylate acrylate, and silver-plated nano graphite sheets were mixed in a stirring kettle according to a mass ratio of 35:30:1:5:3:3:1:1.5 for mixing and stirring operation. The temperature was adjusted to 30℃ for continuous mixing and stirring for 15min to prepare the pressure-sensitive adhesive mixture.

(2) In the nitrogen atmosphere, heat diamino propyl tetramethyl disiloxane to 95℃, add diamino propyl tetramethyl disiloxane 0.015 times the mass of tetramethyl disiloxane, reaction 1.5 h later, add diamino propyl tetramethyl disiloxane mass of 2.2 times the methyl phenyl siloxane ring body, continue to react for 10h, temperature rise to 140℃.

After 1.5h of reaction, cooling to room temperature, reducing pressure to 10mmHg, warming to 160℃, and holding for 6h, terminal aminopropyl polymethyl phenyl siloxane was prepared. Under a nitrogen atmosphere, ammonia will end with propyl methyl phenyl siloxane and N, N  dimethyl formamide mixed in quality than 1:15 stir until dissolved, after joining the ammonia propyl methyl phenyl siloxane quality 0. 28 times are benzene tetracarboxylic acid two poles, continue to stir until dissolved, after let stand for 30 h, produce self-adhesive;

(3) The mass ratio of phenol, epichlorohydrin, and potassium hydroxide was 5:20: 2 Mixed and heated in a water bath to 80℃, stirred at 100rpm for 8h, added epichlorohydrin with 0.2 times the mass of potassium hydroxide, heated to 90℃, continued to stir for 8h, and filtered with 300 mesh filter while hot and steamed for 2 ~ 3h, then filtered again with 300 mesh filter to obtain aryl epichlorohydrin; The mass ratio of aroxyepichlorohydrin, phenol, formaldehyde, and ammonia water with the mass fraction of 5 ~ 10% is 1:8:3: After stirring at 200rpm for 5h, pressure reduction distillation for 8h was carried out at 0.004mpa at the same temperature. After vacuum distillation, the heating was stopped.

When cooling to 40℃, anhydrous ethyl alcohol with a mass of 0.6 aryl oxyepxychlorohydrin was added, and viscosifying resin was prepared by stirring evenly. The pressure-sensitive glue mixture is divided into two parts: pressure-sensitive glue mixture A and pressure-sensitive glue mixture A. The pressure-sensitive glue mixture A is introduced into another stirring kettle, and the pressure-sensitive glue mixture mass is 0.02 times benzoyl peroxide, the pressure-sensitive glue mixture mass is 0.08 times viscosifying resin, and pressure sensitive glue mixture mass 0.15 times self-made crosslinking agent are added.

The temperature is raised to 80℃. After the reaction for 50min, add pressure-sensitive adhesive mixture A to mix the stirring raw materials, cool down to 75℃, react for 5h, and stand for 1.5h, solvent type conductive pressure-sensitive adhesive is prepared.

Adhesives are widely used in People’s Daily life, providing a variety of conveniences for people’s life. Pressure Sensitive Adhesive (PSA) is a very important adhesive. Psa is very sensitive to pressure and can be strongly bonded to the adhesive by applying mild pressure without the need for solvent, heat, or other means.

Since the last century, the research and application of pressure-sensitive adhesive have been rapidly developed and has been widely used in all walks of life. Rubber-type pressure sensitive adhesive (RPSAs) is made of rubber elastomer as a matrix, with appropriate viscosifying resin, filler, softener, crosslinking agent, solvent, and so on. It is a kind of adhesive that can be closely bonded with the adhesive with small pressure.

It is widely used in single and double side adhesive tape, trademarks, labels, medical supplies and electronic products, and other fields. So far, there are several theories to explain the bonding mechanism, including adsorption theory, mechanical interlock theory, diffusion theory, and electrostatic theory. The bonding mechanism of pressure-sensitive adhesive is as follows: it will have viscous flow after being subjected to external pressure and can fully contact the substrate surface.

When the pressure-sensitive adhesive has sufficient wettability to the substrate surface, the molecules between the interface can contact closely and generate intermolecular force to achieve adsorption equilibrium and generate strong adhesion. The molecular weight of the rubber is usually higher, so it is necessary to add other additives, such as viscosities, softener, and solvent, to reduce the viscosity of rubber and increase the adhesive property of rubber. However, there are still some problems with rubber pressure-sensitive adhesive.

For example, rubber generally has a high molecular weight, so its viscosity is higher, despite the addition of a large number of viscosifying resins and softeners, but its initial viscosity is low; There are still unreacted double bonds in rubber elastomers, which are easy to age under the action of light and heat despite the addition of antioxidant. The glass transition temperature of some rubber is relatively high, and it is easy to fail at low temperatures. At the same time, after the preparation of the existing rubber pressure-sensitive glue, the edge of the PET film is partially coated with glue and partially without glue due to the uneven coating of pressure-sensitive glue. Therefore, the area not coated with pressure-sensitive glue needs to be cut and removed. However, the width of the cutting can not be determined according to the actual distribution of pressure sensitive adhesive, resulting in the normal part being cut, resulting in waste.

It is very important to develop a new type of pressure-sensitive adhesive which can be used in a high and low-temperature environment.

Adhesives are widely used in People’s Daily life, providing a variety of conveniences for people’s life. Pressure Sensitive Adhesive (PSA) is a very important adhesive. Psa is very sensitive to pressure and can be strongly bonded to the adhesive by applying mild pressure without the need for solvent, heat, or other means. Since the last century, the research and application of pressure-sensitive adhesive have been rapidly developed and has been widely used in all walks of life. Acrylate pressure-sensitive adhesive is the most widely used pressure-sensitive adhesive in the market at present.

It is the copolymer of acrylate monomers and other vinyl monomers, with good bonding strength, aging resistance, weather resistance, good transparency, medium resistance, no phase separation and migration, and other excellent properties. The bonding mechanism of pressure-sensitive adhesive is as follows: it will have viscous flow after being subjected to external pressure and can fully contact with the substrate surface.

When the pressure-sensitive adhesive has sufficient wettability to the substrate surface, the molecules between the interface can contact closely and generate intermolecular force to achieve adsorption equilibrium and generate strong adhesion. Therefore, the pressure-sensitive adhesive must have good viscoelasticity and good wettability to the substrate in order to produce sufficient adhesion. However, at low temperatures, when the temperature is close to or lower than the glass transition temperature (Tg) of the pressure-sensitive adhesive, the molecular chain segment movement of the polymer in the pressure-sensitive adhesive is limited, and the pressure-sensitive adhesive cannot fully contact with the substrate, resulting in bonding failure.

At high temperatures, the solvent in the pressure-sensitive adhesive may volatilize, resulting in the failure of the pressure-sensitive adhesive; At the same time, at high temperatures, the molecular chain of the pressure-sensitive adhesive becomes soft, unable to provide enough cohesion, resulting in the decline of bonding performance. In recent years, the research of high-temperature or low-temperature resistant pressure-sensitive adhesives has made some progress, but these preparation methods are usually more complex, and can not take into account the high and low-temperature resistance. Therefore, it is very important to develop a new type of pressure-sensitive adhesive which can be used in high and low-temperature environments.

With the development of the economy and information technology, online shopping has become a way of life. Most of the goods we receive are packed in paper express boxes. As the number of online shoppers grows, so does the use of paper packaging boxes for express delivery. The traditional carton packaging is based on the layer winding of BOPP single-sided tape. The tape usage of a single carton is large.

Because BOPP film is difficult to degrade in the environment, the burden on the environment is greater. In recent years, the carton cover is pre-fitted with double-sided cotton paper tape.

When users use it, they only need to open the release paper and press it together by hand to complete the solid packaging of the carton, which effectively avoids the large use of BOPP sealing tape. The existing carton with double-sided tape in the winter in the north, most of the tape at low-temperature conditions pressure sensitivity is poor, can not be effectively bonded, individual at low-temperature conditions can effectively bond, but the carton is easy to tear traceless, and can not play the role of anti-theft. In the process of transportation, when encountering a high-temperature environment, it is easy to pop open, resulting in the failure of the sealing box, which brings great loss to users.

To achieve the purpose of the good bonding effect that is not easy to bounce off now offers the following technical scheme: a wide WenYu using pressure sensitive adhesive, including the following materials: 100 copies, acrylic polymers solution viscosity resin 10 -15, 25, 1 -polybutylene crosslinking agent 1 -3 copies. Step 1 Prepare acrylic polymer solution: In a blender, thermometer, nitrogen import, reflux condenser tube, and dropping funnel of the investment in the reaction vessel as the monomer composition-BA and 2 EHA, AA, 2-HEA, as a polymerization solvent of ethyl acetate, the import of nitrogen stirring for 1 hour at the same time, in such a way to remove oxygen inside the polymerization system, and then add AIBN as a polymerization initiator.

The solution of acrylic polymer was obtained by heating polymerization.

Step two, make the pressure-sensitive adhesive solution before coating: in the acrylic polymer solution prepared in step one, viscosifying resin, polymethyl butene, and necessary diluent, and then add isocyanate crosslinking agent and stir mixing, so as to make the pressure-sensitive adhesive solution to be coated;

Step 3: Make double-sided tape: the pressure-sensitive adhesive is coated on the release paper, dried to form a pressure-sensitive adhesive layer, and then transferred to the cotton paper substrate. In addition, the same pressure-sensitive adhesive layer formed by drying is transferred to the other side of the cotton paper substrate, and cooked at 40 ℃ for 3 days in the drying room to obtain the double-sided tape;

Step 4: Performance test: Cut the double-sided tape into splines 15mm wide and 300mm long for use, and then paste the prepared tape on the cartons in different temperature environments. After a certain period of time, check the ripping state of the tape.