TWI510557B - Oligomer, pressure sensitive adhesives composition and method for manufacturing pressure sensitive adhesive - Google Patents

Description

Oligomer, pressure sensitive adhesive composition, and method for forming pressure sensitive adhesive

The present invention relates to an oligomer, more particularly to a pressure sensitive adhesive composition formed therewith and a method of forming a pressure sensitive adhesive.

Pressure sensitive adhesives (PSAs) are pressure-sensitive adhesives that are adhesives that can be adhesively applied under light pressure. Generally, traditional pressure sensitive adhesives are mainly made of a large amount of petroleum products, which not only causes waste of resources, but also cannot be recycled after use, which also causes waste disposal problems and improves environmental load. In recent years, due to the high price of petroleum raw materials and the importance of green environmental protection issues, the use of biomass resources to replace traditional petrochemical raw materials has become an active research and development direction.

An oligomer according to an embodiment of the present invention is obtained by copolymerizing 100 parts by weight of a soybean oil derivative with 10 to 50 parts by weight of a polyfunctional carboxylic acid, wherein the polyfunctional carboxylic acid is itaconic acid A combination of succinic acid and a weight ratio of itaconic acid to succinic acid of between 1:1 and 3:1.

A pressure sensitive adhesive composition according to an embodiment of the present invention comprises: 100 parts by weight of an oligomer; and 1 to 5 parts by weight of an initiator, wherein the oligomer comprises the above oligomer.

A method for forming a pressure sensitive adhesive according to an embodiment of the present invention comprises: mixing 100 parts by weight of an oligomer with 3 to 20 parts by weight of a first surfactant to form a first reaction solution, wherein the oligomer comprises the above Oligomer; mixing 325 to 665 parts by weight of water and 3 to 20 parts by weight of the second surfactant to form a second reaction solution; adding the second reaction solution to the first reaction solution and heating to form an emulsified solution; The initiator is added to the emulsified solution, and the emulsified solution is heated to carry out a thermal crosslinking reaction; the emulsified solution is coated on the substrate to form a film; and the film is dried to form a pressure sensitive adhesive.

A method for forming a pressure sensitive adhesive according to an embodiment of the present invention comprises: mixing 100 parts by weight of an oligomer with 3 to 20 parts by weight of a first surfactant to form a first reaction solution, wherein the oligomer comprises the above-mentioned oligomer Polymer; mixing 325 to 665 parts by weight of water and 3 to 20 parts by weight of the second surfactant to form a second reaction solution; adding the photoinitiator to the first reaction solution or the second reaction solution; The reaction solution is added to the first reaction solution and heated to form an emulsified solution; the emulsified solution is coated on the substrate to form a film; and the film is dried and irradiated to form a pressure sensitive adhesive.

In one embodiment, the oligomer can be formed by polymerizing a soybean oil derivative with a polyfunctional carboxylic acid having a reactive double bond. The soybean oil derivative may include epoxidized soybean oil, acidified soybean oil, acrylic soybean oil, or the like. The polyfunctional carboxylic acid can be itaconic acid or itaconic acid (itaconic) Acid) in combination with succinic acid. Taking epoxidized soybean oil as an example, it has low Tg characteristics, and has a reactive epoxy functional group at the end of the molecular chain. By the action of the catalyst, the epoxy functional group of the epoxidized soybean oil will produce a ring opening reaction. The co-acid and succinic acid react to form a colloidal molecular oligomer with high adhesion.

The above oligomer is prepared by adding 10 to 50 parts by weight of a polyfunctional carboxylic acid, and 0.4 to 1.5 parts by weight of a catalyst, and 0.0625 to 0.25 parts by weight of an inhibitor based on 100 parts by weight of the soybean oil derivative. It is dissolved in 40 to 70 parts by weight of a solvent and heated to 70 to 90 ° C for 6 to 24 hours. The acid value can be measured during the reaction. When the acid value is no longer decreased, it means that the ring-opening grafting reaction of the epoxidized soybean oil with the polyfunctional carboxylic acid ends. If the amount of the polyfunctional carboxylic acid is too high, the reaction cannot be completed completely, and the unreacted polyfunctional carboxylic acid precipitates after completion of the reaction, which affects subsequent applications. If the amount of the polyfunctional carboxylic acid is too low, the oligomer has a low viscosity. If the temperature of the heating reaction is too high and/or the reaction time is too long, the double bond in the oligopolymer will cause chain polymerization due to high temperature or excessive reaction time, causing the oligopolymer to form a crosslinked macromolecular structure, affecting Subsequent pressure sensitive adhesive preparation. If the temperature of the heating reaction is too low and/or the reaction time is too short, the temperature is too low or the time is too short, so that the epoxy functional group of the epoxy soy oil and the carboxylic acid functional group of itaconic acid or succinic acid cannot be completely completed. Ring-opening grafting reaction. The weight ratio of itaconic acid to succinic acid in the polyfunctional carboxylic acid is between 1:1 and 3:1. If the proportion of itaconic acid is too high, the epoxidized soybean oil/itaconic acid oligopolymer has too many single molecular double bonds, resulting in excessive crosslinkability and loss of adhesion when the subsequent polymerization of the pressure sensitive molecules. If the proportion of itaconic acid is too low, it will greatly reduce the sense of follow-up because it cannot provide enough hydrophilic functional groups (such as carboxylic acid functional groups). Adhesive adhesion. The catalyst may be an organophosphorus compound such as triphenylphosphine (TTP). The inhibitor can be 4-methoxyphenol (MEHQ). The solvent may be a polar organic solvent such as isopropyl alcohol (IPA), 2-ethyl ketone (Methyl Ethyl Ketone), N-methylpyrrolidone (NMP), ethanol (EtOH), or a combination thereof. The oligomer formed has a number average molecular weight of between 5,000 and 9,000, each oligomer molecule has 3 to 12 double bond functional groups, and the adhesion is between 5 gf and 1000 gf, and The fast tack (Tack) is between 50gf and 600gf. In the above oligomer, if the ratio of the double bond is too high, the oligomer is easily self-crosslinked in the process of producing the pressure sensitive adhesive, resulting in loss of viscosity; if the ratio of the double bond is too low, it is easy to make The pressure sensitive adhesive produced is low in viscosity. If the number average molecular weight of the oligomer is too high, it means that the epoxidized soybean oil itself undergoes ring-opening polymerization to reduce the graft amount of itaconic acid and/or succinic acid. If the number average molecular weight of the oligomer is too low, it means that the graft reaction of the epoxidized soybean oil with itaconic acid and/or succinic acid does not occur.

In one embodiment, the above oligomers can be used in a pressure sensitive adhesive. For example, the pressure sensitive adhesive composition may include a total of 100 parts by weight of the oligomer, 1 to 6 parts by weight of the initiator, and 30 to 50 parts by weight of the solvent, and the oligomer includes the above oligomer ( It is made up of soybean oil derivative, itaconic acid, and succinic acid). In an embodiment of the invention, the pressure sensitive adhesive may further comprise from 10 to 100 parts by weight of other oligomers, such as oligomers formed by copolymerization of a soybean oil derivative with itaconic acid. The starter may include an oily or aqueous photoinitiator or a hot starter. The aqueous hot starter can be sodium persulfate. The oily thermal initiator can be 2,2'-Azobis (2-methylpropionitrile, AIBN) and Benzoyl Peroxide (BPO). The aqueous photoinitiator can be 2,2-2-B 2,2-Diethoxyacetophenone. The oily photoinitiator can be 1-hydroxy-cyclohexyl-phenyl-ketone. The solvent may be a polar organic solvent such as isopropyl alcohol (IPA), 2-ethyl ketone (Methyl Ethyl Ketone), N-methylpyrrolidone (NMP), ethanol (EtOH), or a combination thereof. It is worth noting that if the oligomer is synthesized by a solvent method, an aqueous initiator will not be used.

The pressure sensitive adhesive composition may further comprise a surfactant, including an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant (anionic and nonionic mixed, cationic and nonionic) One of the types is mixed, a biotype surfactant, or a combination thereof. Anionic surfactants such as sodium dodecyl sulfate (SDS, available from Acros), sodium benzenesulfonate (from Acros), dioctyl sodium sulfosuccinate (AEROSOL OT) -75, purchased from Acros). Cationic surfactants such as cetyltrimethylammonium bromide (CTAB, available from Acros), cetyltrimethylammonium chloride (CTAC, available from Acros). Nonionic surfactants such as nonyl phenol-40 mole ethylene oxide aduct (NP-40, purchased from Sino-Japanese Synthetic), or linear alcohol ethoxylate (linear alcohol) Ethoxylate, purchased from Sino-Japanese Synthetic). The biotype surfactant may be sodium lauryl ether sulphate.

The above pressure sensitive adhesive composition can be used to form a pressure sensitive adhesive, and the preparation method is divided into an aqueous phase or a solvent phase.

In an embodiment of the solvent phase preparation, 1 to 6 parts by weight of the initiator and 30 to 50 parts by weight of the organic solvent are added based on 100 parts by weight of the oligomer. After the agent is uniformly stirred, it is coated on a substrate to form a coating. The oligomer includes the above oligomer (made of a soybean oil derivative, itaconic acid, and succinic acid). In an embodiment of the present invention, the solvent phase may further be added with 10 to 100 parts by weight of other oligomers, such as an oligomer formed by copolymerization of a soybean oil derivative with itaconic acid. In the preparation of the solvent phase, whether the initiator is a photoinitiator or a hot initiator, it is an oil phase initiator. If a hot initiator is used, the mixture may be heated and stirred before coating to form a crosslinking reaction, and the crosslinked oligomer solution is coated on the substrate to form a coating, followed by drying. The coating forms a pressure sensitive adhesive. If a photoinitiator is used, the uniformly stirred mixture can be applied to the substrate, and after drying the coating, the oligomer can be crosslinked, that is, a pressure sensitive adhesive is formed. The substrate can be paper, polypropylene, polyvinyl chloride, polyethylene, polyethylene terephthalate (PET), polyimine (PI), or cloth fibers.

In one embodiment, if the substrate is a permeable material such as paper, 3.5 to 6 parts by weight of a rocking agent such as fumed cerium oxide, precipitated dioxide is further added based on 100 parts by weight of the oligomer.矽 and/or organic bentonite to prevent the coating from wetting the substrate.

In one embodiment of the aqueous phase preparation, the aqueous phase solution and the oil phase solution are separately prepared. The aqueous phase solution may include 325 to 665 parts by weight of water, 3 to 20 parts by weight of a surfactant, and 0.06 to 0.12 parts by weight of an antifoaming agent, based on 100 parts by weight of the oligomer. The oil phase solution may include 100 parts by weight of the oligomer, 0.5 to 3 parts by weight of the co-stabilizer, and 3 to 20 parts by weight of the surfactant. The oligomer includes the above oligomer (made of a soybean oil derivative, itaconic acid, and succinic acid). In an embodiment of the present invention, the oil phase solution may further be added with 10 to 100 parts by weight of other oligomers, such as the oligomer formed by the copolymerization of the soybean oil derivative and itaconic acid. Polymer. Then, the mini-emulsion preparation is carried out, the aqueous phase solution is added to the oil phase solution, the temperature in the reactor is raised to between 30 ° C and 35 ° C, and then stirred and mixed for 30 minutes to 1 hour to form a pre-emulsion, and then a homogenizer is used to form a mini. Emulsion. Next, the aforementioned mini emulsion was introduced into the reactor, heated to between 65 ° C and 85 ° C in a hot water bath, and nitrogen gas was introduced for 10 to 30 minutes to remove oxygen dissolved in the emulsion. The hot starter solution (aqueous or oily) is then added to the reactor to initiate free radical addition polymerization, and the pH is adjusted to between 6.5 and 7.5 with aqueous ammonia, and the temperature is maintained at 65 ° C during the reaction. Between 85 ° C, while the stirring rate is maintained at 150 rpm to 250 rpm, the reaction is continued for 2 to 8 hours to crosslink the oligomer. Finally, it was cooled again and the oversized particles were removed with 40 mesh (0.42 mm) and 200 mesh (0.074 mm) screens, attached to the stirrer, thermometer, and reactor wall, and collected as much as possible. The resulting pressure-sensitive adhesive composition has a theoretical solid content of 35 to 50% by weight. Finally, the above pressure sensitive adhesive composition is coated on a substrate, and after drying in an oven, a pressure sensitive adhesive is formed. The surfactant of the above aqueous phase solution may be an anionic surfactant such as sodium dodecyl sulfate (SDS), sodium benzenesulfonate or dioctyl sodium sulfosuccinate. (AEROSOL OT-75). The antifoaming agent of the above aqueous phase solution may be an organic antifoaming agent such as BYK 024. The co-stabilizer of the above oil phase solution may be Stearyl methacrylate (SMA). The surfactant of the above oil phase solution may be a nonionic surfactant such as Nonyl phenol-40 mole ethylene oxide aduct (NP-40), linear alcohol ethoxylate. (Linear alcohol ethoxylate). The above aqueous hot starter may be sodium persulfate (SPS). The above oily thermal initiator may be AIBN or BPO.

In an embodiment of the aqueous phase preparation, the aqueous phase solution and the oil phase solution are separately prepared, and the aqueous phase solution may include 325 to 665 parts by weight of water and 3 to 20 parts by weight based on 100 parts by weight of the oligomer. The surfactant, and 0.06 to 0.12 parts by weight of an antifoaming agent. The oil phase solution may include 100 parts by weight of the oligomer, 0.5 to 3 parts by weight of the co-stabilizer, and 3 to 20 parts by weight of the surfactant. If the photoinitiator is aqueous, the photoinitiator can be added to the aqueous phase solution. If the photoinitiator is oily, the photoinitiator can be added to the oil phase solution. The photoinitiator is used in an amount of 2 to 5 parts by weight based on 100 parts by weight of the oligomer. The oligomer includes the above oligomer (made of a soybean oil derivative, itaconic acid, and succinic acid). In an embodiment of the invention, the oligomer may further comprise other oligomers, such as oligomers formed by copolymerization of a soybean oil derivative with itaconic acid. Then, the mini-emulsion preparation is carried out, the aqueous phase solution is added to the oil phase solution, the temperature in the reactor is raised to between 30 ° C and 35 ° C, and then stirred and mixed for 30 minutes to 1 hour to form a pre-emulsion, and then a homogenizer is used to form a mini-emulsion. . Finally, the oversized particles were removed with 40 mesh (0.42 mm) and 200 mesh (0.074 mm) screens, attached to the stirrer, thermometer and reactor wall, and collected as much as possible. The resulting pressure-sensitive adhesive composition has a theoretical solid content of 35 to 50% by weight. Finally, the pressure sensitive adhesive composition is applied onto a substrate, dried, and then irradiated to crosslink the oligomer to form a pressure sensitive adhesive. The surfactant of the above aqueous phase solution may be an anionic surfactant such as sodium dodecyl sulfate (SDS), sodium benzenesulfonate or dioctyl sodium sulfosuccinate. (AEROSOL OT-75). The antifoaming agent of the above aqueous phase solution may be an organic antifoaming agent such as BYK 024. The co-stabilizer of the above oil phase solution may be stearyl methacrylate (SMA). The surfactant of the above oil phase solution may be Nonionic surfactants such as nonyl phenol-40 mole ethylene oxide aduct (NP-40), linear alcohol ethoxylate. The above aqueous photoinitiator can be 2,2-Diethoxyacetophenone. The above oily photoinitiator can be Ciba® IRGACURE® 184 or Ciba® IRGACURE® 819. The aforementioned drying and illuminating steps may use a UV dryer at a drying rate of about 3 to 6 m/min.

The oligomer of the present invention can adjust the desired adhesive property by adjusting the graft ratio of the soybean oil derivative to itaconic acid and succinic acid; further, by mixing different oligomers and different The preparation method comprises the control of a pressure sensitive adhesive having different adhesive properties, the adhesion of which is between 5gf and 1000gf, and the rapid viscosity (Tack) is between 50gf and 600gf. The pressure sensitive adhesive of the invention can be applied to various types of adhesive tapes, such as sealing tape, double-sided tape, kraft paper tape, foam tape, sticky note, or stationery tape.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

Example

In the following examples, the molecular weight of the oligomer was measured using a gel chromatography apparatus: the oligomer obtained by the following examples appropriately diluted with DMF was previously prepared, and injected into a gel chromatograph to DMF is blended with the extract, and the standard molecular weight solution (Standard) can read the molecular weight of the product after different UV polymerization from the computer. After testing and analysis, the number average molecular weight of the oligomer is 5000 to 9000.

In the following examples, the amount of adhesion and adhesion test (Tack) of oligomer, epoxidized soybean oil/itaconic acid/succinic acid mixture, pressure sensitive adhesive, etc. The test methods are ASTM D3330 and ASTM D6195: the oligomers obtained in the following Example 1, Example 2 and Comparative Example 1, the epoxidized soybean oil/itaconic acid/succinic acid mixture were directly added to the UV light initiator ( Light starter type: 284, usage amount: 3%), after being uniformly stirred, coated on the surface of the PET substrate with a 60 μm doctor blade, and after drying, UV drying rate (UV curing rate 5 m/min) was applied. A pressure-sensitive adhesive film having a film thickness of about 25 μm and having adhesive properties was formed. Then, adhesion and fast tack (Tack) tests were performed using ASTM D3330 and ASTM D6195, respectively.

In the following examples, the colloidal particle size measurement of the greening pressure sensitive adhesive was measured using a laser light scattering particle size analyzer (Otsuka, Photal LPA-3000/3100).

Example 1 (oligomer)

Itaconic acid was added in a ratio of 12.5 to 50 parts by weight based on 100 parts by weight of epoxidized soybean oil (CP CIZER B-22, Changchun Petrochemical Co., Ltd.). Further adding 0.4 parts by weight of triphenylphosphine (TPP) as a catalyst, 0.0625 to 0.25 parts by weight of 4-methoxyphenol (MEHQ) as an inhibitor, and dissolving in 41.67 parts by weight of ethanol (EtOH), isopropanol (IPA), methyl ethyl ketone (MEK), N-methylpyrrolidone (NMP) and other organic solvent. It was first heated to 70 ° C and stirred for 1 hour to completely dissolve. It was then heated to 90 ° C and allowed to react for 24 hours. The reacted oligomer was tested for adhesion and rapid viscosity. The test results are shown in Table 1. Among them, No. 1E4I, itaconic acid was added in an amount of 50 parts by weight to 100 parts by weight of epoxidized soybean oil, and after completion of the reaction, a portion of itaconic acid was precipitated, indicating that the proportion of itaconic acid added was excessive.

From the results of FTIR analysis, it was observed from the spectrum that the absorption peak of the epoxy group at about 840 cm ^{-1 was} observed because the itaconic acid was added and the grafting reaction was produced, so that the absorption peak was significantly reduced; the ester at 940 cm ^-1 was similar. The absorption peak, and the hydroxyl absorption peak in the range of 3470 cm ^-1 , because the itaconic acid was added and reacted, the FTIR absorption peak here increased. In addition, there is an absorption peak of a carbon-carbon double bond in the vicinity of 1640 cm ^-1 , which indicates that itaconic acid does not cause the double bond functional group to be destroyed by the ring-opening reaction with the epoxidized soybean oil at a high temperature. The subsequent polymerization of the pressure sensitive colloidal molecules could not be carried out.

As a result of NMR analysis, it was observed from the spectrum that the hydrogen position of the epoxy functional group near 3 disappeared after the graft reaction, and the hydrogen position map on itaconic acid appeared near 6-7. By comparison of the NMR analysis, it was confirmed that itaconic acid had successfully reacted with the epoxy functional group of the epoxidized soybean oil; and the double bond functional group of the itaconic acid molecule was retained.

Example 2 (oligomer)

Based on 100 parts by weight of epoxidized soybean oil (CP CIZER B-22, Changchun Petrochemical Co., Ltd.), itaconic acid and succinic acid are added to the epoxidized ratio at a ratio of 12.5 to 50 parts by weight of the total weight of the two. Mix in soybean oil. Further adding 0.4 parts by weight of Triphenylphosphine (TPP) as a catalyst, 0.0625 To 0.25 parts by weight of 4-methoxyphenol (MEHQ) as an inhibitor, it was dissolved in 41.67 parts by weight of isopropyl alcohol. It was first heated to 70 ° C and stirred for 1 hour to completely dissolve. It was then heated to 90 ° C and allowed to react for 24 hours. The reacted oligomer was tested for adhesion and rapid viscosity. The test results are shown in Table 2. Wherein, compared with the first embodiment, the number 1E3I1S, the total weight of both itaconic acid and succinic acid is 50 parts by weight, and 100 parts by weight of the epoxidized soybean oil is mixed and reacted to complete the cooling, not only without itaconic acid or succinic acid. Precipitating, and the viscosity and fast viscosity of the obtained oligomers are greatly improved, indicating that the addition of succinic acid helps to increase the reaction amount of the polyfunctional carboxylic acid with the epoxidized soybean oil, thereby improving the adhesion of the oligomer and Fast viscosity.

From the results of FTIR analysis, it was observed from the spectrum that the absorption peak of the epoxy group at about 840 cm ^{-1 was} observed because the itaconic acid was added and the grafting reaction was produced, so that the absorption peak was significantly reduced; the ester at 940 cm ^-1 was similar. The absorption peak, and the hydroxyl absorption peak in the range of 3470 cm ^-1 , because itaconic acid and succinic acid were added, and the reaction was made, the FTIR absorption peak here increased. In addition, there is an absorption peak of carbon-carbon double bond near 1640 cm ^-1 , which shows that itaconic acid and succinic acid do not react with epoxidized soybean oil at high temperature to make it double-bonded. The base is destroyed, and subsequent polymerization of the pressure sensitive colloidal molecules cannot be performed.

As a result of NMR analysis, it was observed from the spectrum that the hydrogen position of the epoxy functional group near 3 disappeared after the graft reaction, and the hydrogen position map on itaconic acid appeared near 6-7. By comparison of NMR analysis, it was confirmed that itaconic acid and succinic acid have been successfully reacted with the epoxy functional group of the epoxidized soybean oil; and the double bond functional groups of the itaconic acid and succinic acid molecules are still retained.

Comparative Example 1 (epoxidized soybean oil/itaconic acid/succinic acid mixture)

The itaconic acid and succinic acid were added to the epoxidized soybean oil in a ratio of 25 parts by weight based on 100 parts by weight of the epoxidized soybean oil, and dissolved in 41.67 parts by weight of isopropyl alcohol. The results of the adhesion test (shown in Table 2) show that the epoxidized soybean oil/itaconic acid/succinic acid mixture which has not undergone polymerization to form an oligomer is not sticky.

Example 3 Solvent phase sensitive adhesive

The soybean oil oligomer 1E3I1S obtained from the isopropanol solvent phase obtained in Example 2 was mixed with the butanone (MEK) solvent phase soybean oil oligomer 1E2IM obtained in Example 1 in a different ratio, and a shaker was added ( AEROSIL® R805 EVONIK-degus, 6wt%), then add UV light initiator (Ciba® IRGACURE® 184, usage: 3wt%), stir evenly, apply with 60μm doctor blade, apply after UV coating through UV dryer After drying (UV curing rate 5 m/min), a pressure-sensitive adhesive film having a film thickness of about 25 μm and having adhesive properties was formed. The pressure sensitive adhesive which completed the reaction was tested for adhesion and quick adhesion. The test results are shown in Table 3.

Example 4 (thermal polymerization aqueous phase pressure sensitive adhesive)

The aqueous phase and the oil phase solution are separately prepared. The aqueous phase solution is 665 g of water, 7 g of anionic surfactant sodium dodecyl sulfate (SDS), and 7 g of defoamer BYK 024 (Berke, Germany, 0.1- 1% (total)) Stir well. The oil phase solution was 100 g of the epoxidized soybean oil oligomer (1E1I1S, 1E2I1S, 1E3I1S) prepared in Example 2, and 5 g of the stabilizer octadecyl methacrylate (SMA, available from Mitsubishi Rayon). About 5% (accumulating oil phase), 7 g of surfactant 287 (medium-day synthesis, about 14% (oil phase)) is stirred evenly.

Prepare a mini emulsion, slowly add the aqueous phase solution to the oil phase solution in the reaction tank at room temperature, then raise the temperature inside the reactor to 70 ° C, and then use a mechanical stirrer to separate the aqueous phase and the oil phase at 800 rpm. Mix well for 1 hour. Subsequently, the resulting pre-emulsion was further homogenized by a homogenizer for 1 hour. Next, the formed miniemulsion was added to the reactor and heated to 80 ° C in a hot water bath. Nitrogen gas was introduced into the reactor feed liquid for 10 minutes to remove oxygen dissolved therein, and then 3 g of an aqueous hot starter sodium persulfate (SPS) aqueous solution was added to the reactor to initiate free radical addition. The polymerization reaction was carried out, and the pH was adjusted to 6.5 to 7.5 with ammonia water. The temperature was maintained at about 80 ° C during the reaction, while the stirring rate was maintained at about 200 rpm, and the reaction was continued for 4 hours. Finally, the latex product is cooled and 40mesh respectively. The (0.42mm) and 200mesh (0.074mm) screens remove excess particles, and the filter residue attached to the mixer, thermometer and reactor wall is also collected as much as possible. The resulting aqueous phase sensitizing composition has a theoretical solids content of 35-50%.

The aqueous phase pressure sensitive adhesive composition was applied onto a PET substrate with a 60 μm doctor blade, and dried in an oven at 60 ° C to form a green pressure sensitive adhesive film having a film thickness of about 10 μm . The pressure sensitive adhesive which completed the reaction was tested for adhesion and quick adhesion, and the test results are shown in Table 4.

Example 5 (UV polymerization aqueous phase pressure sensitive adhesive)

The aqueous phase and the oil phase solution are separately disposed. The aqueous phase solution is 665 g of water, 7 g of an anionic surfactant sodium dodecyl sulfate (SDS), 0.4 g of defoamer BYK 024 (Berke, Germany, 0.1 -1% (total)) Stir well. The oil phase solution is 100 g of the epoxidized soybean oil oligomer (1E1I1S, 1E2I1S, 1E3I1S) prepared in Example 2, and 5 g of the stabilizer octadecyl methacrylate (SMA, available from Mitsubishi Rayon, about 5). % (accumulating oil phase)), 7 g of surfactant 287 (Chinese-Japanese synthesis, about 14% (oil phase)), and 3 g of oily photoinitiator Ciba® IRGACURE® 184 are evenly mixed.

Prepare a mini emulsion and slowly add the aqueous phase solution at room temperature. The oil phase solution in the tank should be raised, then the temperature in the reactor was raised to 70 ° C, and the aqueous phase and the oil phase were thoroughly mixed at 800 rpm for 1 hour with a mechanical stirrer. Subsequently, the resulting pre-emulsion is further homogenized using a homogenizer for a period of between 30 minutes and 1 hour. Finally, the oversized particles were removed with 40mesh (0.42mm) and 200mesh (0.074mm) filters, and the filter residue attached to the agitator, thermometer and reactor wall was collected as much as possible. The resulting aqueous phase sensitizing composition has a theoretical solids content of 35-50%.

The aqueous sensitizing pressure-sensitive adhesive composition was applied onto a PET substrate with a 60 μm doctor blade, and dried by a UV dryer (UV curing rate: 5 m/min) to form a green sensitized pressure-sensitive adhesive film having a film thickness of about 10 μm. The pressure-sensitive adhesives obtained by the reaction were tested for adhesion and quick-adhesion, and the test results are shown in Table 5.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

Claims (13)

An oligomer obtained by copolymerizing 100 parts by weight of a soybean oil derivative with 10 to 50 parts by weight of a polyfunctional carboxylic acid, wherein the polyfunctional carboxylic acid is a combination of itaconic acid and succinic acid, and The weight ratio of itaconic acid to succinic acid is between 1:1 and 3:1. The oligomer of claim 1, wherein the oligomer has a number average molecular weight of 5,000 to 9,000. The oligomer of claim 1, wherein the oligomer contains 3 to 12 double bond functional groups per molecule. A pressure sensitive adhesive composition comprising: 100 parts by weight of an oligomer, and the oligomer comprises the oligomer according to claim 1; 1 to 5 parts by weight of an initiator; and 30 to 50 Parts by weight of organic solvent. The pressure sensitive adhesive composition of claim 4, further comprising 10 to 100 parts by weight of an oligomer of soybean oil derivative and itaconic acid. The pressure sensitive adhesive composition of claim 4, wherein the oligomer has a number average molecular weight of 5,000 to 9,000. The pressure sensitive adhesive composition of claim 4, wherein the oligomer contains 3 to 12 double bond functional groups per molecule. The pressure sensitive adhesive composition of claim 4, wherein the organic solvent comprises isopropanol, methyl ethyl ketone, N-methylpyrrolidone, ethanol, or a combination thereof. For example, the pressure sensitive adhesive composition described in claim 4 of the patent scope includes 325 to 665 parts by weight of water and 3 to 20 parts by weight of a surfactant. A method for forming a pressure sensitive adhesive comprising: mixing 100 parts by weight of an oligomer with 3 to 20 parts by weight of a first surfactant to form a first reaction solution, wherein the oligomer includes the first item of the patent application scope The oligo; mixing 325 to 665 parts by weight of water and 3 to 20 parts by weight of the second surfactant to form a second reaction solution; adding the second reaction solution to the first reaction solution and heating, Forming an emulsified solution; adding a hot starter to the emulsified solution, and heating the emulsified solution to perform a thermal crosslinking reaction; coating the emulsified solution on a substrate to form a film; and drying the film to form A pressure sensitive adhesive. The method for forming a pressure sensitive adhesive according to claim 10, wherein after the step of heating the second reaction solution into the first reaction solution, a homogenization step is further included. A method for forming a pressure sensitive adhesive comprising: mixing 100 parts by weight of an oligomer with 3 to 20 parts by weight of a first surfactant to form a first reaction solution, wherein the oligomer includes the first item of the patent application scope The oligomer; mixing 325 to 665 parts by weight of water and 3 to 20 parts by weight of the second surfactant to form a second reaction solution; adding a photoinitiator to the first reaction solution or the first In the second reaction solution; The second reaction solution is added to the first reaction solution and heated to form an emulsified solution; the emulsified solution is coated on a substrate to form a film; and the film is dried and irradiated to form a pressure sensitive adhesive. The method for forming a pressure sensitive adhesive according to claim 12, wherein after the step of heating the second reaction solution into the first reaction solution, a homogenization step is further included.