An acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength post-growth and preparation method and application thereof

Abstract

The present invention discloses an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength and a preparation method and application thereof. The adhesive is a multi-polymer prepared by emulsion polymerization using acrylic monomers, benzene ring-containing functional monomers and cross-linking monomers. The present invention introduces benzene ring-containing functional monomers through structural design, and the rigid benzene ring increases the cohesion of the pressure-sensitive adhesive. At the same time, the functional groups such as chloromethyl, methoxy, tert-butyl and fluoro groups on the benzene ring can also effectively increase the bonding performance of the pressure-sensitive adhesive, thereby effectively achieving the effective unification of cohesion and adhesion. In addition, a cross-linking monomer is introduced into the polymer structure of the pressure-sensitive adhesive, and the introduction of the cross-linking monomer further changes the cross-linking density of the pressure-sensitive adhesive system, thereby making it show a more excellent performance in inhibiting the post-growth of peel strength. Finally, by optimizing and regulating the ratio and composition of the raw materials, the requirements of different application fields can be met, and the application prospects are broad.

Description

Technical Field

[0001] The invention belongs to the technical field of functional water-based polymer materials, and in particular relates to an acrylic emulsion pressure-sensitive adhesive that effectively inhibits the post-growth of peel strength, and a preparation method and application thereof. Background Art

[0002] During the transportation, storage, processing and assembly of goods, it is often necessary to protect the surface of materials and parts. One of the common methods is to stick a protective film on the surface of the protected object, that is, surface protective film. The main function of surface protective film is to protect the surface of the goods to a certain extent. It is also called protective tape or pressure-sensitive protective film. Generally, polymer plastic film or special paper is used as the base material, and rubber, silicone, polyurethane and polyacrylate are used as pressure-sensitive adhesives (usually referred to as pressure-sensitive adhesives). It is processed by coating and drying. The main properties that the protective film should have are: first, it can have suitable adhesion to the surface of different protected materials, and the protective film will not warp or fall off during the material handling and processing. There is no pressure-sensitive adhesive residue when peeling off the protective film; secondly, it is inert to the surface of the protected material, does not react with it, does not corrode, and does not pollute the surface of the material. At present, protective films have been widely used in machinery, instrumentation, electronics, home appliances, ships, construction and automobile manufacturing.

[0003] At present, the pressure-sensitive adhesives for protective films mainly include rubber, acrylate, silicone and polyurethane. Among them, acrylate pressure-sensitive adhesives are pressure-sensitive in themselves, and they have the advantages of uniform adhesive layer components, colorless, transparent, antioxidant and good low-temperature resistance, so they occupy an important position in the field of pressure-sensitive adhesives. Acrylic pressure-sensitive adhesives are used in various forms such as solvent-based, emulsion-based, hot-melt and radiation-cured. Among them, the most widely used are solvent-based and emulsion-based acrylate pressure-sensitive adhesives. Compared with solvent-based pressure-sensitive adhesives, emulsion-based pressure-sensitive adhesives are green and environmentally friendly, low-cost, and have a simple, safe and easy-to-control preparation process. Therefore, emulsion-based acrylate pressure-sensitive adhesives are increasingly used to replace solvent-based pressure-sensitive adhesives. Among the various types of pressure-sensitive adhesives currently produced in my country, acrylate emulsion pressure-sensitive adhesive tapes account for about 50%. At the same time, the balance between initial adhesion, peel strength and sustained adhesion, high temperature resistance, water resistance and weather resistance of emulsion-based acrylic pressure-sensitive adhesives cannot reach the level of solvent-based acrylic pressure-sensitive adhesives, which to a certain extent limits the further development of emulsion-based acrylic pressure-sensitive adhesives. Therefore, modifying emulsion-based acrylic pressure-sensitive adhesives to prepare high-performance emulsion-based acrylic pressure-sensitive adhesives can no longer meet the needs of application scenarios, customer differences, and time and space changes. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention proposes an acrylic emulsion pressure-sensitive adhesive capable of effectively inhibiting the post-growth of peel strength, and a preparation method and application thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength is prepared by emulsion polymerization of acrylic monomers, benzene ring-containing functional monomers and cross-linking monomers; the mass ratio of the acrylic monomers, benzene ring-containing functional monomers and cross-linking monomers is (30-40): (5-10): (0.5-2).

[0007] Furthermore, the following raw materials are included, calculated by weight: 30-40 parts of acrylic monomer, 5-10 parts of benzene ring-containing functional monomer, 0.5-2 parts of cross-linking monomer, 0.3-0.7 parts of emulsifier, 0.1-0.3 parts of initiator, 0.8-1.5 parts of defoaming agent and 50-60 parts of deionized water.

[0008] Furthermore, the acrylic monomer is one or more combinations of acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate and isooctyl acrylate.

[0009] Furthermore, the benzene ring-containing functional monomer is one or a combination of p-chloromethylstyrene, pentafluorostyrene, p-methoxystyrene and p-tert-butylstyrene.

[0010] Furthermore, the cross-linking monomer is one or a combination of diethyl diallyl malonate, dipropylene terephthalate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate and neopentyl glycol dimethacrylate.

[0011] Furthermore, the emulsifier is one or a combination of nonylphenol polyoxyethylene ether ammonium sulfate, alkyl alcohol alkoxylated sulfate sodium salt, nonylphenol ethoxylated sulfate ammonium salt, alkyl alcohol ethoxylated sulfate sodium salt, sodium dodecyl sulfate, allyloxy nonylphenol polyoxyethylene ether ammonium sulfate and sodium vinyl sulfonate.

[0012] Furthermore, the initiator is one or more combinations of ammonium persulfate, potassium persulfate and sodium persulfate.

[0013] The present invention also provides a method for preparing the acrylic emulsion pressure-sensitive adhesive having high efficiency in inhibiting the post-growth of peel strength, comprising the following steps:

[0014] 1) mixing a portion of an emulsifier and a portion of deionized water, adding an initiator and stirring evenly, and then sequentially adding an acrylic monomer and a benzene ring-containing functional monomer for emulsification to obtain a pre-emulsion;

[0015] 2) Mix the remaining emulsifier and deionized water and heat to 80°C, then start to drop the pre-emulsion after heating, add the cross-linking monomer after the addition is completed, continue to heat to 85°C, keep warm for 1 hour, then cool to 30-40°C, adjust the pH value to weak alkaline (about 7-8) with ammonia water, add defoaming agent, filter and remove impurities, and obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0016] The present invention also provides an application of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth as a protective film for household appliances, aluminum profiles, carbon profiles and plastic profiles.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] (1) The present invention introduces a benzene ring-containing functional monomer through structural design. The rigid benzene ring increases the cohesion of the acrylic emulsion pressure-sensitive adhesive. At the same time, the functional groups such as chloromethyl, methoxy, tert-butyl and fluorine on the benzene ring can also effectively increase the bonding performance of the pressure-sensitive adhesive, thereby achieving an effective unification of cohesion and adhesion. In addition, the cross-linking monomer is introduced into the structure of the acrylic pressure-sensitive adhesive, which further changes the cross-linking density of the pressure-sensitive adhesive system, thereby making it show a more efficient performance of inhibiting the growth of peel strength.

[0019] (2) The present invention relates to an acrylic emulsion pressure-sensitive adhesive that efficiently inhibits the post-peel strength growth, and can meet the needs of different application fields by optimizing and regulating the ratio and composition of the raw materials.

[0020] (3) The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth of the present invention is an emulsion system with water as solvent, which does not involve organic solvents such as acetone and xylene. At the same time, no other small molecule curing agent needs to be added during the curing process. It is green and environmentally friendly and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 This is the synthesis route of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength involved in Example 1. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0025] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0026] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] The raw materials used in the following examples of the present invention are all commercially available.

[0029] In order to solve the deficiencies of the prior art, the primary purpose of the present invention is to provide an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth, and the present invention also provides a method for preparing the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth.

[0030] Another object of the present invention is to provide an application of an acrylic emulsion pressure-sensitive adhesive that can effectively inhibit the post-peel strength growth, which is specifically applied to protective films in the fields of home appliances, aluminum profiles, carbon profiles, and plastic profiles.

[0031] In order to solve the problems existing in the prior art and achieve the technical purpose of the present invention, the present invention designs and prepares an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength based on the molecular structure design of acrylic emulsion pressure-sensitive adhesive and the bonding mechanism of adhesive. The specific technical scheme is as follows:

[0032] The invention discloses an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength. The adhesive is prepared by emulsion polymerization of acrylic monomers, benzene ring-containing functional monomers and cross-linking monomers, and is a multi-component copolymer. The mass ratio of the acrylic monomers, benzene ring-containing functional monomers and cross-linking monomers is (30-40): (5-10): (0.5-2).

[0033] In some preferred embodiments, the highly efficient post-peel strength growth inhibiting acrylic emulsion pressure-sensitive adhesive of the present invention comprises the following raw materials, measured by weight: 30-40 parts of acrylic monomer, 5-10 parts of benzene ring-containing functional monomer, 1-3 parts of cross-linking monomer, 0.3-0.7 parts of emulsifier, 0.1-0.3 parts of initiator, 0.8-1.5 parts of defoaming agent and 50-60 parts of deionized water.

[0034] In some preferred embodiments, the acrylic monomer is one or more combinations of acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate and isooctyl acrylate. More preferably, it is one or more combinations of acrylic acid, methyl methacrylate and isooctyl acrylate (all purchased from Yantai Wanhua, with a purity greater than 97%).

[0035] In some preferred embodiments, the benzene ring-containing functional monomer is one or a combination of p-chloromethylstyrene, pentafluorostyrene, p-methoxystyrene and p-tert-butylstyrene, and more preferably one or a combination of p-chloromethylstyrene and pentafluorostyrene (both analytically pure).

[0036] In some preferred embodiments, the crosslinking monomer is one or a combination of diallyl malonate, diallyl terephthalate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate. More preferably, it is one or a combination of two of diallyl malonate and diallyl terephthalate (both are analytically pure).

[0037] In some preferred embodiments, the emulsifier (reactive type) is an anionic emulsifier, specifically one or more combinations of nonylphenol polyoxyethylene ether ammonium sulfate, alkyl alcohol alkoxylated sulfate sodium salt, nonylphenol ethoxylated sulfate ammonium salt, alkyl alcohol ethoxylated sulfate sodium salt, sodium lauryl sulfate, allyloxy nonylphenol polyoxyethylene ether ammonium sulfate and sodium vinyl sulfonate. More preferably, one or more combinations of nonylphenol polyoxyethylene ether ammonium sulfate (CO436, Rhodia), alkyl alcohol alkoxylated sulfate sodium (AS801, Dow Chemical), allyloxy nonylphenol polyoxyethylene ether ammonium sulfate (DNS86, Double Bond Chemistry) and sodium vinyl sulfonate.

[0038] In some preferred embodiments, the initiator is one or more combinations of ammonium persulfate, potassium persulfate and sodium persulfate, more preferably one or two combinations of ammonium persulfate and potassium persulfate, and the initiator is used in the form of a 25% initiator aqueous solution.

[0039] In some preferred embodiments, the defoaming agent is 0.8-1.5 parts.

[0040] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth prepared by emulsion polymerization of acrylic acid, methyl methacrylate, isooctyl acrylate, p-chloromethylstyrene and diethyl diallylmalonate has a structure of formula (I):

[0041]

[0042] The present invention also provides a method for preparing the acrylic emulsion pressure-sensitive adhesive having high efficiency in inhibiting the post-growth of peel strength, comprising the following steps:

[0043] 1) Add 80wt% (80wt% refers to the added amount, i.e., add 80% of the total mass of the emulsifier first, and add the remaining 20% ​​later) of emulsifier and 40wt% of deionized water into a pre-emulsification reactor, then add an initiator aqueous solution with a mass concentration of 25%, stir evenly, then add acrylic monomers and benzene ring-containing functional monomers in sequence, emulsify for 0.5-1h, and obtain a pre-emulsion;

[0044] 2) Add the remaining emulsifier and deionized water into the polymerization reactor, stir and heat to 80°C, start to drop the pre-emulsion after heating, control the dropping time to 3.5-4h, add the cross-linking monomer at one time after the dropping is completed, continue to heat to 85°C, keep warm for 1h, then cool to 30-40°C, adjust the pH value to weak alkaline (about 7-8) with ammonia water, add defoaming agent, filter and remove impurities with a 180-mesh filter, and obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0045] The present invention also provides an application of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth as a protective film for household appliances, aluminum profiles, carbon profiles and plastic profiles.

[0046] The following examples serve as further illustrations of the technical solutions of the present invention.

[0047] Example 1

[0048] The invention discloses an acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water into a pre-emulsification reaction kettle, then adding 2 kg of a 25 wt% ammonium persulfate aqueous solution, stirring to make the mixture uniform, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate and 20 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsion; then, adding the pre-emulsion into a polyurethane emulsion; Add 90kg of deionized water and 0.3kg of CO436 into the reaction kettle, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diethyl diallyl malonate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0049] Example 2

[0050] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of pentafluorostyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diethyl diallyl malonate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0051] Example 3

[0052] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-methoxystyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diallyl malonate diethyl ester at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0053] Example 4

[0054] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-tert-butyl styrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diallyl malonate diethyl ester at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0055] Example 5

[0056] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of dipropylene terephthalate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0057] Example 6

[0058] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of pentafluorostyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 4kg of dipropylene terephthalate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0059] Example 7

[0060] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-methoxystyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 4kg of dipropylene terephthalate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0061] Example 8

[0062] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-tert-butyl styrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 4kg of dipropylene terephthalate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0063] Example 9

[0064] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 20 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsion; then in a polymerization reactor, Add 90kg of deionized water and 0.3kg of CO436 into the reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 1.5kg of trimethylolpropane trimethacrylate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h, then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0065] Example 10 (Compared with Example 1, the amount of chloromethylstyrene used is changed)

[0066] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate, and 25 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of CO436 into the polymerization reactor, stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diallyl malonate diethyl ester at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0067] Example 11 (Compared with Example 10, the type of emulsifier is changed)

[0068] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength post-growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of alkyl alcohol alkoxylated sodium sulfate (AS801) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 65 kg of isooctyl acrylate, and 25 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then Add 90kg of deionized water and 0.3kg of AS801 into the polymerization reactor, stir and heat to 80°C, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diallyl malonate diethyl ester at one time after the dripping is completed, then heat to 85°C, keep the reaction for 1h and then cool to 40°C, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth.

[0069] Example 12

[0070] An acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength post-growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of allyloxy nonylphenol polyoxyethylene ether ammonium sulfate (DNS86) and 60 kg of deionized water to a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 65 kg of isooctyl acrylate, and 25 kg of p-chloromethylstyrene, emulsifying for 1 hour to obtain a pre-emulsion; then in a polymerization reaction kettle, Add 90kg of deionized water and 0.3kg of ammonium sulfate of nonylphenol polyoxyethylene ether (CO436) into the kettle, stir and heat to 80°C, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diethyl diallyl malonate at one time after the dripping is completed, then heat to 85°C, keep the reaction for 1h and then cool to 40°C, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0071] Example 13

[0072] An acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength and a preparation method thereof, comprising the following steps: adding 1.2 kg of allyloxy nonylphenol polyoxyethylene ether ammonium sulfate (DNS86) and 60 kg of deionized water into a pre-emulsification reactor, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 65 kg of isooctyl acrylate, and 25 kg of pentafluorostyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then in a polymerization reactor Add 90kg of deionized water and 0.3kg of ammonium sulfate of nonylphenol polyoxyethylene ether (CO436), stir and heat to 80℃, start to drip the pre-emulsion, control the dripping time to 4h, add 3kg of diethyl diallyl malonate at one time after the dripping is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0073] Embodiment 14

[0074] An acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-growth of peel strength and a preparation method thereof, comprising the following steps: adding 0.6 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436), 0.6 kg of allyloxy nonylphenol polyoxyethylene ether ammonium sulfate (DNS86), and 60 kg of deionized water into a pre-emulsification reactor, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to mix evenly, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 65 kg of isooctyl acrylate, and 25 kg of pentafluorostyrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then add 90kg of deionized water and 0.3kg of ammonium sulfate of nonylphenol polyoxyethylene ether (CO436) into the polymerization reactor, stir and heat to 80°C, start to drip the pre-emulsion, control the dripping time to 4h, add 1.5kg of trimethylolpropane trimethacrylate at one time after the dripping is completed, then heat to 85°C, keep the reaction temperature for 1h and then cool to 40°C, adjust the pH value to weak alkalinity (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0075] Comparative Example 1

[0076] The invention discloses an acrylic emulsion pressure-sensitive adhesive capable of effectively inhibiting the post-growth of peeling strength and a preparation method thereof. The invention comprises the following steps: adding 1.2 kg of ammonium sulfate of nonylphenol polyoxyethylene ether (CO436) and 60 kg of deionized water into a pre-emulsification reaction kettle, then adding 2 kg of 25% ammonium persulfate aqueous solution, stirring to make the mixture uniform, then sequentially adding 4 kg of acrylic acid, 41 kg of methyl methacrylate and 70 kg of isooctyl acrylate, emulsifying for 1 hour to obtain a pre-emulsified liquid; then adding 90 kg of deionized water and 0.3 kg of CO436 into a polymerization reaction kettle, stirring and heating to 80 DEG C, starting to drip the pre-emulsion, controlling the dripping time to be 4 hours, then heating to 85 DEG C, keeping the temperature for reaction for 1 hour, then cooling to 40 DEG C, adjusting the pH value to be weakly alkaline (about 7-8) with ammonia water, finally adding 2.5 kg of defoamer, filtering and removing impurities with a 180-mesh filter, and obtaining the acrylic emulsion pressure-sensitive adhesive capable of effectively inhibiting the post-growth of peeling strength.

[0077] Comparative Example 2

[0078] The invention discloses an acrylic emulsion pressure-sensitive adhesive capable of effectively inhibiting the post-growth of peeling strength and a preparation method thereof. The invention comprises the following steps: adding 1.2 kg of ammonium sulfate of nonylphenol polyoxyethylene ether (CO436) and 60 kg of deionized water into a pre-emulsification reaction kettle, then adding 2 kg of a 25% aqueous solution of ammonium persulfate, stirring to make the mixture uniform, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate and 25 kg of styrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then adding 90 kg of deionized water and 0.3 kg of CO436 into a polymerization reaction kettle, stirring and heating to 80 DEG C, starting to drip the pre-emulsion, controlling the dripping time to be 4 hours, then heating to 85 DEG C, keeping the temperature for reaction for 1 hour, then cooling to 40 DEG C, adjusting the pH value to be weakly alkaline (about 7-8) with ammonia water, finally adding 2.5 kg of a defoaming agent, filtering and removing impurities with a 180-mesh filter, and obtaining the acrylic emulsion pressure-sensitive adhesive capable of effectively inhibiting the post-growth of peeling strength.

[0079] Comparative Example 3

[0080] The invention discloses an acrylic emulsion pressure-sensitive adhesive with high efficiency and inhibition of peel strength growth and a preparation method thereof, comprising the following steps: adding 1.2 kg of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 60 kg of deionized water into a pre-emulsification reaction kettle, then adding 2 kg of a 25% ammonium persulfate aqueous solution, stirring to make the mixture uniform, then sequentially adding 4 kg of acrylic acid, 16 kg of methyl methacrylate, 70 kg of isooctyl acrylate and 25 kg of styrene, emulsifying for 1 hour to obtain a pre-emulsified liquid; then, adding the pre-emulsified liquid into a polyurethane emulsion; Add 90kg of deionized water and 0.3kg of CO436 into the reaction kettle, stir and heat to 80℃, start to add the pre-emulsion, control the adding time to 4h, add 3kg of diethyl diallyl malonate at one time after the adding is completed, then heat to 85℃, keep the reaction for 1h and then cool to 40℃, adjust the pH value to weak alkaline (about 7-8) with ammonia water, finally add 2.5kg of defoamer, filter and remove impurities with a 180-mesh filter to obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

[0081] Performance Testing

[0082] The performance test of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth involved in the present invention includes the performance of the pressure-sensitive adhesive such as appearance, stability, emulsion particle size and distribution, etc. Among them, due to the high solid content of the pressure-sensitive adhesive, the particle size and distribution of all acrylic emulsion pressure-sensitive adhesives of the present invention are the strength particle size results after dilution 100 times and 1000 times, as shown in Table 1.

[0083] Table 1 Particle size and distribution of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength growth according to the present invention

[0084]

[0085] Most of the commercially available acrylic emulsion pressure-sensitive adhesives are milky white liquids, and the stability generally requires that the adhesive should not be stratified for six months, and the particle size is basically between 100-200nm. The present invention adopts pre-emulsification polymerization technology, and utilizes acrylic functional monomers, benzene ring-containing functional monomers and cross-linking monomers to prepare a kind of high-efficiency anti-peel strength rear growth acrylic emulsion through emulsion polymerization. The result shows that after the acrylic emulsion prepared by the present invention introduces the cross-linking functional monomer, the test result shows that its stability is still excellent, and it is not stratified for six months. Taking Example 14 as an example, after the introduction of the cross-linking monomer of the trifunctionality, the viscosity of the system rises significantly, in order to effectively inhibit the gel and improve the storage stability of the emulsion, it is necessary to appropriately reduce the amount of the cross-linking monomer. At the same time, compared with Comparative Examples 1 and 2, the emulsion particle size of the present invention has a tendency to increase due to cross-linking, and the particle size distribution is widened, and the overall particle size is also between 150-240nm, and the particle size distribution is also narrow, all between 0.15-0.40, so it is also very suitable for use as an emulsion pressure-sensitive adhesive.

[0086] The performance test and characterization of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth prepared by the present invention mainly include the following: (1) testing the initial adhesion performance of the pressure-sensitive tape according to GB / T4852-2002, (2) testing the 180° peel strength of the pressure-sensitive tape according to GB / T2792-1998, and (3) testing the shear resistance of the pressure-sensitive tape according to GB / T4851-1998. The specific test results are shown in Table 2.

[0087] Table 2 Adhesive properties of acrylic emulsion pressure-sensitive adhesives with high efficiency in inhibiting peel strength growth prepared in the embodiments of the present invention

[0088]

[0089] The results show that compared with Comparative Examples 1 and 2, Comparative Example 1 only involves acrylic functional monomers, so its initial adhesion is large, but the cohesive energy of the system is small, resulting in low sustained adhesion; Comparative Example 2 adds styrene hard monomers on the basis of Comparative Example 1, thereby improving the cohesive energy of the system and improving its sustained adhesion. Overall, the initial adhesion, 180° peel strength and sustained adhesion of the systems of Comparative Examples 1 and 2 are poor, and there are deficiencies such as weak adhesion and glue falling. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth prepared by the present invention is prepared based on traditional functional acrylic functional monomers and supplemented with benzene ring-containing functional monomers and functional cross-linking monomers, which effectively realizes the effective unification of cohesive force and adhesive force, and thus exhibits excellent initial adhesion, 180° peel strength and sustained adhesion.

[0090] In addition, the test of the post-peel strength growth performance of the pressure-sensitive adhesive was carried out in accordance with GB / T2792-1998 for testing the 180° peel strength of the pressure-sensitive adhesive tape, i.e., the aluminum plate was selected as the substrate, the pressure-sensitive adhesive was coated on the black and white film with a 30-wire coating rod and the glue amount was controlled to 15g, and then pressed onto the aluminum plate, and then the 180° peel strength at the initial stage, 7d, 14d, 30d, 90d and 180d was measured respectively. The results are shown in Table 3.

[0091] Table 3 Adhesive properties of acrylic emulsion pressure-sensitive adhesives with high efficiency in inhibiting peel strength growth prepared in the embodiments of the present invention

[0092]

[0093] In Comparative Example 1, there is no benzene ring-containing functional monomer in the polymerized monomer, in Comparative Example 2, only styrene is used as a benzene ring-containing functional monomer, and there is no other functional group on the benzene ring. In Comparative Example 3, a cross-linking monomer is added on the basis of Comparative Example 2. The results show that although Comparative Example 1 shows relatively good bonding performance, its 180° peel strength continues to increase with time, so that when the film is applied for too long, the protective film cannot be easily peeled off, which seriously affects the performance of the protective film. Comparative Example 2 introduces styrene monomer on the basis of Comparative Example 1. Although the introduction of benzene ring increases the cohesion of the system and can inhibit the growth of peel strength to a certain extent, the effect is not obvious, and the introduction of rigid benzene ring also leads to a decrease in its bonding strength. Comparative Example 3 introduces a cross-linking monomer on the basis of Example 2. The introduction of the cross-linking monomer further increases the cohesion of the adhesive system, but also significantly reduces the bonding strength of the system, thereby limiting its further application.

[0094] The present invention introduces a benzene ring-containing functional monomer through structural design. The rigid benzene ring increases the cohesion of the acrylic emulsion pressure-sensitive adhesive. At the same time, the functional groups such as chloromethyl, methoxy, tert-butyl and fluorine on the benzene ring can also effectively increase the bonding performance of the pressure-sensitive adhesive, thereby achieving an effective unification of cohesion and adhesion. In addition, a cross-linking monomer is introduced into the structure of the acrylic emulsion pressure-sensitive adhesive, which further changes the cross-linking density of the pressure-sensitive adhesive system, thereby making it exhibit a more excellent performance in inhibiting the growth of peel strength.

[0095] The highly efficient post-peel strength growth inhibiting acrylic emulsion pressure-sensitive adhesive of the present invention can also meet the requirements of different application fields by optimizing and regulating the ratio and composition of the raw materials. In addition, the highly efficient post-peel strength growth inhibiting acrylic emulsion pressure-sensitive adhesive of the present invention is an emulsion system with water as a solvent, without involving organic solvents such as acetone and xylene, and at the same time, no other small molecule curing agent needs to be added during the curing process, which is green and environmentally friendly and has broad application prospects.

[0096] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth, characterized in that: The invention is prepared by emulsion polymerization using acrylic monomers, benzene ring-containing functional monomers and crosslinking monomers; the mass ratio of the acrylic monomers, benzene ring-containing functional monomers and crosslinking monomers is (30-40):(5-10):(0.5-2); the benzene ring-containing functional monomers are one or a combination of p-chloromethylstyrene, pentafluorostyrene, p-methoxystyrene and p-tert-butylstyrene.

2. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength post-growth according to claim 1, characterized in that: The raw materials include, by weight: 30-40 parts of acrylic monomer, 5-10 parts of benzene ring-containing functional monomer, 0.5-2 parts of cross-linking monomer, 0.3-0.7 parts of emulsifier, 0.1-0.3 parts of initiator, 0.8-1.5 parts of defoamer and 50-60 parts of deionized water.

3. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength post-growth according to claim 2, characterized in that: The acrylic monomer is one or more combinations of acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate and isooctyl acrylate.

4. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting post-peel strength growth according to claim 2, characterized in that: The cross-linking monomer is one or a combination of diethyl diallyl malonate, dipropylene terephthalate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate and neopentyl glycol dimethacrylate.

5. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength post-growth according to claim 2, characterized in that: The emulsifier is one or a combination of nonylphenol polyoxyethylene ether ammonium sulfate, alkyl alcohol alkoxylated sulfate sodium salt, nonylphenol ethoxylated sulfate ammonium salt, alkyl alcohol ethoxylated sulfate sodium salt, sodium dodecyl sulfate, allyloxy nonylphenol polyoxyethylene ether ammonium sulfate and sodium vinyl sulfonate.

6. The acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting peel strength post-growth according to claim 2, characterized in that: The initiator is one or more combinations of ammonium persulfate, potassium persulfate and sodium persulfate.

7. A method for preparing an acrylic emulsion pressure-sensitive adhesive having high efficiency in inhibiting the post-growth of peel strength as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: 1) mixing a portion of an emulsifier and a portion of deionized water, adding an initiator and stirring evenly, and then sequentially adding an acrylic monomer and a benzene ring-containing functional monomer for emulsification to obtain a pre-emulsion; 2) Mix the remaining emulsifier and deionized water and heat to 80°C, then start to drop the pre-emulsion after heating, add the cross-linking monomer after the addition is completed, continue to heat to 85°C, keep warm for 1 hour, then cool to 30-40°C, adjust the pH to 7-8 with ammonia water, add defoaming agent, filter and remove impurities, and obtain an acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the growth of peel strength.

8. Use of the acrylic emulsion pressure-sensitive adhesive with high efficiency in inhibiting the post-peel strength growth as claimed in any one of claims 1 to 6 as a protective film for household appliances, aluminum profiles, carbon profiles and plastic profiles.

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