CN114874750A - Water-based adhesive for bonding rubber and metal and preparation method thereof - Google Patents
Water-based adhesive for bonding rubber and metal and preparation method thereof Download PDFInfo
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- CN114874750A CN114874750A CN202210681550.9A CN202210681550A CN114874750A CN 114874750 A CN114874750 A CN 114874750A CN 202210681550 A CN202210681550 A CN 202210681550A CN 114874750 A CN114874750 A CN 114874750A
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J195/00—Adhesives based on bituminous materials, e.g. asphalt, tar, pitch
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/04—Non-macromolecular additives inorganic
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/06—Non-macromolecular additives organic
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
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- Adhesives Or Adhesive Processes (AREA)
Abstract
The invention belongs to the technical field of adhesives, and particularly relates to a water-based adhesive for bonding rubber and metal and a preparation method thereof, wherein the water-based adhesive comprises 20-25 parts of deionized water, 8-10 parts of polystyrene, 10-12 parts of glass, 5-7 parts of an emulsifier, 5-7 parts of an initiator, 5-7 parts of a tackifier, 5-7 parts of a thickener, 3-5 parts of a curing agent, 8-12 parts of asphalt, 2-3 parts of an acrylate copolymer, 5-6 parts of a coupling agent, 7-9 parts of kaolin and 4-6 parts of a chloride solution; the invention has the advantages of high curing speed and large bonding area, and can realize stronger bonding speed and strength.
Description
Technical Field
The invention belongs to the technical field of adhesives, and particularly relates to a water-based adhesive for bonding rubber and metal and a preparation method thereof.
Background
The fluororubber adhesive is a special adhesive product taking fluororubber as a main material, has excellent heat resistance, oil resistance and air aging resistance, and is mainly used for bonding fluororubber and metal materials. According to the curing process, the fluororubber adhesive can be divided into a high-temperature vulcanization type and a room-temperature curing type.
The room temperature curing type fluororubber adhesive can complete curing reaction at room temperature under contact pressure, is particularly suitable for working conditions that heating curing cannot be carried out, has poor self-adhesion and mutual adhesion under the condition of no heating, and has the problems of low initial adhesion, low curing speed and low bonding strength in practical application.
Therefore, it is necessary to invent an aqueous adhesive for bonding rubber and metal and a preparation method thereof to solve the above problems.
Disclosure of Invention
In view of the above problems, the present invention provides an aqueous adhesive for bonding rubber and metal and a method for preparing the same, so as to solve the problems mentioned in the background art.
In order to achieve the purpose, the invention provides the following technical scheme: a water-based adhesive for bonding rubber and metal comprises 20-25 parts of deionized water, 8-10 parts of polystyrene, 10-12 parts of glass, 5-7 parts of an emulsifier, 5-7 parts of an initiator, 5-7 parts of a tackifier, 5-7 parts of a thickener, 3-5 parts of a curing agent, 8-12 parts of asphalt, 2-3 parts of an acrylate copolymer, 5-6 parts of a coupling agent, 7-9 parts of kaolin and 4-6 parts of a chloride solution.
Preferably, the coupling agent is a silane coupling agent, and the polystyrene and the glass adopt recycled old tires and old wine bottles.
Preferably, the acrylate copolymer comprises butyl acrylate, isooctyl acrylate, butyl methacrylate and hydroxy acrylate as main components.
Preferably, the silane coupling agent is gamma-epoxypropyletherpropyltrimethoxysilane, gamma-vinyltriethoxysilane, gamma-aminopropyltriethoxysilane, vinyltri-tert-butylperoxysilane, gamma- (methacrylate) propyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane or phenylaminomethyltriethoxysilane.
Preferably, the emulsifier is an anionic emulsifier, in particular ethoxylated nonylphenol sulfosuccinic acid half-ester disodium salt and sodium lauryl sulfate.
Preferably, the chloride ion concentration in the chloride solution is higher than 3 mol/L.
Preferably, the initiator is a persulfate.
A method for preparing the water-based adhesive for bonding rubber and metal comprises the following steps:
the method comprises the following steps: cleaning the recycled tires and wine bottles, respectively crushing the recycled tires and wine bottles, adding the crushed tires into deionized water, adding No. 120 solvent oil, heating and stirring the mixture to dissolve the tires and the wine bottles to form mucilage, wherein the heating temperature is 100 ℃;
step two: adding an initiator, the crushed wine bottle and asphalt into the mucilage formed in the step one, heating to form the mixture, and adding a silane coupling agent, wherein the heating temperature is 70-75 ℃;
step three: then adding emulsification, a tackifier, a thickening agent, a curing agent and an acrylate copolymer, and fully stirring for 1 hour;
step four: finally, the kaolin and the acid liquor are evenly added into the mixture formed in the third step, and the mixture is shaped after being fully stirred for 2 hours, so that the finished adhesive is formed.
The invention has the technical effects and advantages that: the invention has the advantages of high curing speed and large bonding area, and can realize stronger bonding speed and strength.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a flow chart of the preparation process of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort belong to the protection scope of the present invention;
in the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Further, in the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
Example one
A water-based adhesive for bonding rubber and metal comprises 22.5 parts of deionized water, 9 parts of polystyrene, 9 parts of glass, 6 parts of an emulsifier, 6 parts of an initiator, 6 parts of a tackifier, 6 parts of a thickener, 4 parts of a curing agent, 10 parts of asphalt, 2.5 parts of an acrylate copolymer, 5.5 parts of a coupling agent and 8 parts of kaolin.
Preferably, the coupling agent is a silane coupling agent, and the polystyrene and the glass adopt recycled old tires and old wine bottles.
Preferably, the acrylate copolymer comprises butyl acrylate, isooctyl acrylate, butyl methacrylate and hydroxy acrylate as main components.
Preferably, the silane coupling agent is gamma-epoxypropyletherpropyltrimethoxysilane, gamma-vinyltriethoxysilane, gamma-aminopropyltriethoxysilane, vinyltri-tert-butylperoxysilane, gamma- (methacrylate) propyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane or phenylaminomethyltriethoxysilane.
Preferably, the emulsifier is an anionic emulsifier, in particular ethoxylated nonylphenol sulfosuccinic acid half-ester disodium salt and sodium lauryl sulfate.
Preferably, the chloride ion concentration in the chloride solution is higher than 3 mo/L.
Preferably, the initiator is a persulfate.
Example two
A water-based adhesive for bonding rubber and metal comprises 22.5 parts of deionized water, 9 parts of polystyrene, 9 parts of glass, 6 parts of an emulsifier, 6 parts of an initiator, 6 parts of a tackifier, 6 parts of a thickening agent, 4 parts of a curing agent, 10 parts of asphalt, 2.5 parts of an acrylate copolymer, 5.5 parts of a coupling agent, 8 parts of kaolin and 5 parts of a chloride solution.
Preferably, the coupling agent is a silane coupling agent, and the polystyrene and the glass adopt recycled old tires and old wine bottles.
Preferably, the acrylate copolymer comprises butyl acrylate, isooctyl acrylate, butyl methacrylate and hydroxy acrylate as main components.
Preferably, the silane coupling agent is gamma-epoxypropyletherpropyltrimethoxysilane, gamma-vinyltriethoxysilane, gamma-aminopropyltriethoxysilane, vinyltri-tert-butylperoxysilane, gamma- (methacrylate) propyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane or phenylaminomethyltriethoxysilane.
Preferably, the emulsifier is an anionic emulsifier, in particular ethoxylated nonylphenol sulfosuccinic acid half-ester disodium salt and sodium lauryl sulfate.
Preferably, the chloride ion concentration in the chloride solution is higher than 3 mo/L.
Preferably, the initiator is a persulfate.
Comparative example
A water-based adhesive for bonding rubber and metal comprises 20-25 parts of deionized water, 8-10 parts of polystyrene, 10-12 parts of glass, 5-7 parts of an emulsifier, 5-7 parts of an initiator, 5-7 parts of a tackifier, 5-7 parts of a thickener, 3-5 parts of a curing agent, 8-12 parts of asphalt, 2-3 parts of an acrylate copolymer and 5-6 parts of a coupling agent;
experimental procedure
The adhesives of the first and second examples were selected to bond rubber and metal respectively under the same conditions, and the rubber and metal of the first and second examples were subjected to shear strength tests, the results of which are shown in table 1 below:
shear strength | 30 | 40 | 50 | 60 | 80 | 100 |
Example one | Not broken | Not broken | Not broken | Not broken | Not broken | Fracture of |
Example two | Not broken | Not broken | Fracture of | - | - | - |
TABLE 1
The adhesives of the first and the comparative examples were used to bond rubber and metal under the same conditions, respectively, and the curing rates were measured, and the results are shown in Table 2 below
Time | 1 | 2 | 3 | 4 | 5 | 6 |
Example one | Not cured | Not cured | Not cured | Curing | - | - |
Example two | Not cured | Not cured | Not cured | Not cured | Not cured | Curing |
TABLE 2
Comparing the test results in tables 1 and 2 shows that:
1. after kaolin is added, the curing speed of the adhesive can be obviously accelerated, the filler is added into the adhesive to improve the viscosity, the bonding strength, the heat resistance and the wear resistance and reduce the thermal expansion coefficient and the curing shrinkage rate, the filler can improve the cohesive strength of the adhesive and ensure that the adhesive solution has a certain thickness during pressure curing. The kaolin is used as a filler and acts together with the silane coupling agent pair, and the polar groups at two ends of the molecule of the silane coupling agent can firmly combine the organic adhesive and an adherend together, so that the adhesive strength and the mechanical property of the adhesive can be improved.
2. After the chloride solution is added, the shearing strength of the adhesive can be obviously improved, and the chloride solution plays a role in corroding the metal surface, so that the metal surface is rougher, the bonding area of the adhesive and the metal is larger, and the bonding strength of the adhesive and the metal is improved.
Referring to fig. 1, a method for preparing the above-mentioned aqueous adhesive for rubber and metal bonding, which comprises the steps of,
the method comprises the following steps: the recycled tires and wine bottles are cleaned, then are respectively crushed, the crushed tires are added into deionized water, then 120 # solvent oil is added, and the mixture is heated and stirred to be dissolved to form mucilage, wherein the heating temperature is 100 ℃.
Step two: and (2) adding an initiator, the crushed wine bottle and the asphalt into the mucilage formed in the step one, heating to form the mixture, and adding a silane coupling agent, wherein the heating temperature is 70-75 ℃.
Step three: then adding emulsification, a tackifier, a thickening agent, a curing agent and an acrylate copolymer, and fully stirring for 1 hour.
Step four: finally, the kaolin and the acid liquor are evenly added into the mixture formed in the third step, and the mixture is shaped after being fully stirred for 2 hours, so that the finished adhesive is formed.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. An aqueous adhesive for bonding rubber and metal, characterized in that: the adhesive comprises 20-25 parts of deionized water, 8-10 parts of polystyrene, 10-12 parts of glass, 5-7 parts of an emulsifier, 5-7 parts of an initiator, 5-7 parts of a tackifier, 5-7 parts of a thickening agent, 3-5 parts of a curing agent, 8-12 parts of asphalt, 2-3 parts of an acrylate copolymer, 5-6 parts of a coupling agent, 7-9 parts of kaolin and 4-6 parts of a chloride solution.
2. The aqueous adhesive for rubber and metal bonding according to claim 1, wherein: the coupling agent is silane coupling agent, and polystyrene and glass adopt recycled old tires and old wine bottles.
3. The aqueous adhesive for bonding rubber and metal according to claim 1, wherein: the main components of the acrylate copolymer are butyl acrylate, isooctyl acrylate, butyl methacrylate and hydroxyl acrylate.
4. The aqueous adhesive for bonding rubber and metal according to claim 1, wherein: the silane coupling agent is gamma-epoxypropyl ether propyl trimethoxy silane, gamma-vinyl triethoxy silane, gamma-aminopropyl triethoxy silane, vinyl tri-tert-butyl peroxy silane, gamma- (methacrylate) propyl trimethoxy silane, gamma-mercaptopropyl trimethoxy silane or phenylaminomethyl triethoxy silane.
5. The aqueous adhesive for bonding rubber and metal according to claim 1, wherein: the emulsifier is an anionic emulsifier, and specifically is ethoxylated nonylphenol sulfosuccinic acid half-ester disodium salt and sodium dodecyl sulfate.
6. The aqueous adhesive for bonding rubber and metal according to claim 1, wherein: the chloride ion concentration in the chloride solution is higher than 3 mol/L.
7. The aqueous adhesive for bonding rubber and metal according to claim 1, wherein: the initiator is persulfate.
8. A method for preparing the aqueous adhesive for bonding rubber and metal according to any one of claims 1 to 7, characterized in that: the method comprises the following steps:
the method comprises the following steps: cleaning the recycled tires and wine bottles, respectively crushing the recycled tires and wine bottles, adding the crushed tires into deionized water, adding No. 120 solvent oil, heating and stirring the mixture to dissolve the tires and the wine bottles to form mucilage, wherein the heating temperature is 100 ℃;
step two: adding an initiator, the crushed wine bottle and asphalt into the mucilage formed in the step one, heating to form the mixture, and adding a silane coupling agent, wherein the heating temperature is 70-75 ℃;
step three: then adding emulsification, a tackifier, a thickening agent, a curing agent and an acrylate copolymer, and fully stirring for 1 hour;
step four: finally, the kaolin and the acid liquor are evenly added into the mixture formed in the third step, and the mixture is shaped after being fully stirred for 2 hours, so that the finished adhesive is formed.
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1563238A (en) * | 2004-04-12 | 2005-01-12 | 谢兆坤 | Multifunctional environmental protection type adhesive and preparation method |
CN102304333A (en) * | 2011-07-18 | 2012-01-04 | 上海乘鹰新材料有限公司 | Single-component ultraviolet light self-crosslinking type acrylate copolymer emulsion pressure-sensitive adhesive and synthetic method thereof as well as application thereof |
CN106590527A (en) * | 2016-12-17 | 2017-04-26 | 浦北县建业胶合板有限责任公司 | Multifunctional environmentally friendly adhesive and preparation method thereof |
CN110183981A (en) * | 2019-05-30 | 2019-08-30 | 惠州市科域新材料科技有限公司 | Glass plate processing procedure protective film after tearing without residue glue |
CN112175560A (en) * | 2020-09-27 | 2021-01-05 | 湖南安翔科技有限公司 | Water-based adhesive for building material bonding and preparation method thereof |
CN113755103A (en) * | 2021-09-18 | 2021-12-07 | 烟台德邦科技股份有限公司 | Epoxy adhesive with initial pressure sensitivity and preparation method thereof |
-
2022
- 2022-06-16 CN CN202210681550.9A patent/CN114874750A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1563238A (en) * | 2004-04-12 | 2005-01-12 | 谢兆坤 | Multifunctional environmental protection type adhesive and preparation method |
CN102304333A (en) * | 2011-07-18 | 2012-01-04 | 上海乘鹰新材料有限公司 | Single-component ultraviolet light self-crosslinking type acrylate copolymer emulsion pressure-sensitive adhesive and synthetic method thereof as well as application thereof |
CN106590527A (en) * | 2016-12-17 | 2017-04-26 | 浦北县建业胶合板有限责任公司 | Multifunctional environmentally friendly adhesive and preparation method thereof |
CN110183981A (en) * | 2019-05-30 | 2019-08-30 | 惠州市科域新材料科技有限公司 | Glass plate processing procedure protective film after tearing without residue glue |
CN112175560A (en) * | 2020-09-27 | 2021-01-05 | 湖南安翔科技有限公司 | Water-based adhesive for building material bonding and preparation method thereof |
CN113755103A (en) * | 2021-09-18 | 2021-12-07 | 烟台德邦科技股份有限公司 | Epoxy adhesive with initial pressure sensitivity and preparation method thereof |
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