Sealing washer UV adhesive capable of being cured on site, sealing washer product and preparation method of sealing washer UV adhesive
By using on-site curable sealing gasket UV glue, traditional sealing gaskets are solved, and sealing gaskets with high elastic modulus and high elongation are achieved, meeting the sealing needs of special-shaped products and improving production efficiency.
Patent Information
- Application Number
- CN202411714812.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-02-25
AI Technical Summary
Existing traditional universal sealing gaskets are difficult to cope with the problem of sealing special-shaped products, especially in small batches, personalized and performance-variable products.
A field-curable sealing gasket UV glue is used, which consists of acrylate prepolymers, thiol modified prepolymers, active monomers, crosslinking agents, photoinitiators and thixotropic agents, and enhances its elastic modulus and elongation through specific formulations and preparation methods.
The sealing gasket has high elastic modulus, high elongation and good weather resistance, which can meet the sealing needs of special-shaped products and improve production efficiency.
Smart Images
Figure CN119505792A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of UV adhesive for sealing gaskets, and mainly to a UV adhesive for sealing gaskets that can be cured on site, a sealing gasket product and a preparation method thereof. Background Art
[0002] A sealing gasket is a component commonly used to prevent fluid or gas leakage. It is usually made of elastic material and installed at the interface of mechanical equipment to prevent fluid or gas leakage from the interface. Conventional sealing gaskets are generally made of rubber materials, can withstand high temperature and high pressure environments, and have good elasticity and corrosion resistance. However, the manufacturing process of this conventional sealing gasket is complicated, the required manufacturing equipment is huge, and the degree of professionalism is high. It is more suitable for large quantities of universal products with fixed shapes. However, for some small-batch, personalized, and performance-different products, especially those involving special-shaped sealing gasket assemblies with large differences that need to be assembled on site, the use of traditional universal sealing gaskets cannot meet the use requirements. Therefore, it is necessary to propose a UV glue that can be used to make sealing gaskets on site to make up for the shortcomings of traditional sealing processes or the limitations of the use of universal sealing gaskets. Therefore, the existing technology still needs to be improved and developed. Summary of the invention
[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a sealing gasket UV glue that can be cured on site, a sealing gasket product and a preparation method thereof, aiming to solve the problem that existing traditional general-purpose sealing gaskets are difficult to seal special-shaped products.
[0004] The technical solution of this application is as follows: In a first aspect, the present application provides a UV adhesive for sealing gaskets that can be cured on site, wherein the adhesive comprises the following components in parts by weight: 40-70 parts of acrylate prepolymer, 10-30 parts of thiol-modified prepolymer, 10-30 parts of first acrylate active monomer, 1-3 parts of crosslinking agent, 1-3 parts of photoinitiator, 3-5 parts of thixotropic agent; The thiol-modified prepolymer is prepared by Michael addition reaction of thiol and a second acrylate active monomer.
[0005] The present application uses a mercaptan-modified prepolymer containing more sulfur elements to enhance its elastic modulus, so that the resilience of the prepared sealing gasket UV glue after curing is greatly improved. The prepared sealing gasket UV glue has low odor, high thixotropy, good leveling performance, no VOC emissions, and is easy to use. The sealing gasket made by the UV glue has the characteristics of high elastic modulus, high elongation, and good weather resistance.
[0006] Furthermore, the method for preparing the thiol-modified prepolymer comprises the following steps: In a reaction container, a quantitative amount of the mercaptan and a catalyst are added, and the second acrylic ester active monomer is added dropwise under nitrogen protection; After the addition is complete, the temperature is raised to 60-70°C and the reaction is continued for 5 hours until the C=C double bond content is below 0.1%; Lowering the temperature to room temperature to obtain the thiol-modified prepolymer; The molar ratio of the total amount of SH bonds of the added thiol to the total amount of double bonds of the added second acrylic ester reactive monomer is (2-2.05):1; During the dropping process, the temperature of the reaction material is kept below 30° C. by controlling the dropping speed; The thiol is one or more of 1,6-hexanedithiol, trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, and 2,2-bis(mercaptomethyl)-1,3-propyldithiol; The second acrylate active monomer is one or more of 2-phenoxyethyl methacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,4-butanediol diacrylate and caprolactone acrylate; The catalyst is dimethylphenylphosphine, and the added amount of the catalyst is 0.1% of the total weight of the mercaptan-modified prepolymer.
[0007] Further, the thiol is 1,6-hexanedithiol; The second acrylic ester active monomer is 1,4-butanediol diacrylate.
[0008] Furthermore, the acrylate prepolymer is one or more of epoxy acrylate, polyurethane acrylate, polyether acrylate and polyester acrylate; The first acrylic acid ester active monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkoxylated nonylphenol acrylate, ethoxyethoxyethyl acrylate, alkoxydodecyl acrylate and caprolactone acrylate; The crosslinking agent is one or more of ethoxylated bisphenol A diacrylate, ethoxylated pentaerythritol tetraacrylate, polyethylene glycol dimethacrylate and ethoxylated trimethylolpropane triacrylate; The photoinitiator is a combination of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the mass ratio of the 1-hydroxycyclohexyl phenyl ketone to 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is 2:1; The thixotropic agent is fumed silica.
[0009] Furthermore, the acrylate prepolymer is one or two of the polyurethane acrylate and the polyether acrylate, and the molecular weight of the acrylate prepolymer is 10000-15000, and the double bond functionality is 1-2.
[0010] Furthermore, the first acrylic ester active monomer is a combination of hydroxyethyl acrylate and alkoxylated nonylphenol acrylate, and the mass ratio of hydroxyethyl acrylate to alkoxylated nonylphenol acrylate is 1:(1-2).
[0011] Furthermore, the cross-linking agent is polyethylene glycol dimethacrylate.
[0012] In a second aspect, the present application further provides a method for preparing the field-curable UV adhesive for sealing gaskets as described in the first aspect, wherein the method comprises the following steps: Weigh the acrylate prepolymer, the first acrylate active monomer, the crosslinking agent, the photoinitiator and the thixotropic agent according to weight, and stir at a temperature of 40-50° C. and a speed of 1200-1500 r / min for 0.5-1 h until the mixture is uniformly mixed to obtain a mixed solution; Weigh the mercaptan-modified prepolymer according to weight, add it to the mixed solution, stir at a speed of 1200-1500 r / min for 30-40 min, and mix evenly; Then vacuuming, filtering and packaging are performed to obtain the sealing gasket UV glue that can be cured on site.
[0013] In a third aspect, the present application further provides a sealing gasket product, wherein the sealing gasket product is prepared by the sealing gasket UV glue that can be cured on site as described in the first aspect.
[0014] In a fourth aspect, the present application further provides a method for preparing the sealing gasket product as described in the third aspect, comprising the following steps: Select UV curing light source; Using manual dispensing or an automated dispensing machine, the UV glue for the sealing gasket that can be cured on site is extruded into a fixed shape and thickness; The sealing gasket UV glue that can be cured on site is irradiated and cured by an ultraviolet curing light source to obtain the sealing gasket product.
[0015] Beneficial effects: The present application can enhance the elastic modulus of the thiol-modified prepolymer containing more sulfur elements, so that the resilience of the prepared sealing gasket UV glue after curing is greatly improved. The prepared sealing gasket UV glue has low odor, high thixotropy, good leveling performance, no VOC emissions, and is easy to use. The sealing gasket made by the UV glue has the characteristics of high elastic modulus, high elongation, and good weather resistance.
[0016] This application utilizes the high curing efficiency of UV glue and flexible formula adjustment to formulate products with a wide performance span, which can significantly improve production efficiency while meeting the performance requirements. It can produce soft sealing gaskets with high elastic modulus and high elongation, which can be widely used in industry to replace traditional rubber gaskets. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the preparation process of the sealing gasket product of the present application.
[0018] Explanation of the symbols: 1. Automatic dispensing machine; 2. UV glue for sealing gaskets that can be cured on site; 3. Ultraviolet curing light source. DETAILED DESCRIPTION
[0019] The present application provides a UV adhesive for sealing gaskets that can be cured on site, sealing gasket products and preparation methods thereof. To make the purpose, technical scheme and effect of the present application clearer and more specific, the present application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0020] The present application provides a UV adhesive for sealing gaskets that can be cured on site, wherein the adhesive comprises the following components in parts by weight: 40-70 parts of acrylate prepolymer, 10-30 parts of thiol-modified prepolymer, 10-30 parts of first acrylate active monomer, 1-3 parts of crosslinking agent, 1-3 parts of photoinitiator, 3-5 parts of thixotropic agent; The mercaptan-modified prepolymer is prepared by the mercaptan-acrylate Michael addition reaction of mercaptan and a second acrylate active monomer.
[0021] The present application uses a mercaptan-modified prepolymer containing more sulfur elements to enhance its elastic modulus, so that the resilience of the prepared UV adhesive for sealing gaskets after curing is greatly improved. The prepared UV adhesive for sealing gaskets has low odor, high thixotropy, good leveling performance, no VOC emissions, and is easy to use. The sealing gaskets made with the UV adhesive have the characteristics of high elastic modulus, high elongation, and good weather resistance.
[0022] Furthermore, the preparation method of the mercaptan-modified prepolymer comprises the following steps: In a reaction container, a quantitative amount of mercaptan is added, then a catalyst is added, and a second acrylic ester active monomer is added dropwise under nitrogen protection; After the addition is complete, the temperature is raised to 60-70°C and the reaction is continued for 5 hours until the C=C double bond content is below 0.1%; The temperature is lowered to room temperature to obtain a mercaptan-modified prepolymer; During the dropping process, the temperature of the reaction material is kept below 30° C. by controlling the dropping speed.
[0023] Furthermore, in the reaction system, the molar ratio of the total amount of SH bonds of the added thiol to the total amount of double bonds of the added second acrylate active monomer is (2-2.05): 1. In the present application, by using a slightly excessive amount of SH groups, the molecular chains of the thiol-modified prepolymer are provided with SH groups at both ends, which can not only increase the surface drying speed, but also obtain higher resilience when the SH groups are cross-linked during curing.
[0024] The present application uses mercaptan and a second acrylate active monomer as raw materials, and obtains a mercaptan-modified prepolymer through an addition reaction. Through the preparation method of the mercaptan-modified prepolymer provided, the substance obtained by the reaction is a polythiol prepolymer, and its molecular weight is controlled at 3000-4000. In the present application, it is more appropriate to control the molecular weight of the mercaptan-modified prepolymer to 3000-4000. If the molecular weight is too small, the obtained product chain is short, and the cohesive strength and tensile strength are relatively low. If the molecular weight is too high, although the tensile strength will be improved, the viscosity of the UV adhesive prepared will be too high, which is not conducive to industrial use.
[0025] The molecular weight of the mercaptan-modified prepolymer is controlled at a moderate range of 3000-4000. This is mainly because if the molecular weight is too small, the product chain length will be short, and the cohesive strength and tensile strength will be relatively low; if the molecular weight is too high, although the tensile strength is good, the viscosity of the UV glue will be too high, which is not conducive to industrial use.
[0026] Furthermore, the thiol is one or more of 1,6-hexanedithiol, trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, and 2,2-bis(mercaptomethyl)-1,3-propyldithiol.
[0027] Preferably, the thiol is 1,6-hexanedithiol. In the present application, the preferred thiol has a simple structure, a small molecular weight, a high reactivity, a strong controllability, and is easier to produce a polymer with a relatively narrow molecular weight.
[0028] Furthermore, the second acrylic ester reactive monomer is one or more of 2-phenoxyethyl methacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,4-butanediol diacrylate and caprolactone acrylate.
[0029] Preferably, the second acrylate active monomer is 1,4-butanediol diacrylate. In the present application, the preferred 1,4-butanediol diacrylate has a good linear structure and is easier to prepare a polymer with a higher elongation.
[0030] Furthermore, the catalyst is dimethylphenylphosphine, and the amount of the catalyst added is 0.1% of the total weight of the thiol-modified prepolymer (total weight of the product).
[0031] Specifically, taking the raw materials of 1,6-hexanedithiol, 1,4-butanediol diacrylate and dimethylphenylphosphine as an example, the reaction process is as follows:
[0032] Among them, n is 7-10.
[0033] Specifically, in the present application, the thiol-modified prepolymer prepared by the selected raw materials and preparation method has the following characteristics: (1) Highly efficient surface curing performance: Under the condition of low concentration of initiator, the UV glue of the sealing gasket containing the thiol-modified prepolymer can still obtain a surface effect with good surface drying. (2) Moderate curing speed: The thiol-modified prepolymer can play the role of transferring active free radicals, making the overall curing speed slow, and avoiding the excessive reaction speed leading to concentrated heat release. (3) Good resilience: Since the thiol contains more sulfur elements, its elastic modulus can be enhanced, so that the resilience of the cured sealing gasket product is greatly improved. (4) Lower hardness and high elongation: Since the thiol-modified prepolymer is a linear structure, it determines that it has high elongation and low hardness, so that the final product sealing ring has better sealing and peelability.
[0034] Further, the acrylate prepolymer is one or more of epoxy acrylate, polyurethane acrylate, polyether acrylate and polyester acrylate. The amount of the acrylate prepolymer is controlled at 40-70 parts. Preferably, the acrylate prepolymer is one or more of polyurethane acrylate and polyether acrylate, the molecular weight of the acrylate prepolymer is 10000-15000, and the double bond functionality is 1-2. By using the preferred acrylate prepolymer, the obtained sealing gasket has higher elastic modulus, high elongation and good weather resistance.
[0035] Specifically, in the present application, by selecting high molecular weight acrylate prepolymers, the molecular chains are relatively long, which can provide a skeleton for the entire polymer of the reaction, so that the cured UV glue has good flexibility and tensile strength. Due to the high molecular weight of the acrylate prepolymer, by maintaining the double bond density therein, it is also possible to avoid a large shrinkage, which is conducive to ensuring the sealing effect of the UV glue. Moreover, it is also conducive to maintaining the crosslinking degree of the SH bonds between the mercaptan-modified prepolymers, and the cured UV glue can maintain good resilience. Among them, the low double bond density will have a certain influence on the elastic modulus, and the elastic modulus can be appropriately improved by adding an appropriate amount of crosslinking agent according to performance requirements.
[0036] Furthermore, the first acrylate active monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkoxylated nonylphenol acrylate, ethoxyethoxyethyl acrylate, alkoxydodecyl acrylate and caprolactone acrylate. The double bond functionality of the first acrylate active monomer is low, which can ensure that the UV glue of the sealing gasket has a low hardness, is easy to fit and seal with a workpiece of a special shape, and has low odor and high elongation.
[0037] Preferably, the first acrylic ester active monomer is a combination of hydroxyethyl acrylate and alkoxylated nonylphenol acrylate, and the mass ratio of hydroxyethyl acrylate to alkoxylated nonylphenol acrylate is 1:(1-2). In the present application, the selected alkoxylated nonylphenol acrylate contains more alkyl groups, which can give the UV adhesive product softness and make the sealing tighter; and adding a certain amount of hydroxyethyl acrylate, because its molecular chain contains hydroxyl (-OH) groups, can enhance the adhesion to the substrate and improve the tensile strength, so that the product has a high tensile strength while maintaining softness.
[0038] Further, the photoinitiator is a combination of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, and the mass ratio of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide is 2:1. Among them, the selected 1-hydroxycyclohexyl phenyl ketone can accelerate deep curing without yellowing. The selected 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide has good surface drying performance, but yellowing occurs, and the dosage should be moderate. By controlling the appropriate mass ratio, the curing performance and surface drying performance of the UV glue can be improved.
[0039] Further, the crosslinking agent is one or more of ethoxylated bisphenol A diacrylate, ethoxylated pentaerythritol tetraacrylate, polyethylene glycol dimethacrylate and ethoxylated trimethylolpropane triacrylate. Among them, the selected crosslinking agent has a fast curing speed and small shrinkage, and the amount used is 1-3 parts. Preferably, the crosslinking agent is polyethylene glycol dimethacrylate, which effectively improves the double bond crosslinking density and accelerates the reaction speed, while not greatly affecting the flexibility and elongation properties of the product.
[0040] Furthermore, the thixotropic agent is fumed silica, wherein the thixotropic agent can be selected from fumed silica of corresponding brands commercialized on the market according to the rheological requirements of use, and fumed silica can shape the UV glue into various shapes and prevent it from flowing, and the usage amount is 3-5 parts.
[0041] The UV glue for sealing gaskets that can be cured on site provided by this application has low odor, high thixotropy, good leveling performance, no VOC emissions, and is easy to use; the sealing gaskets produced have the characteristics of high elastic modulus, high elongation, good weather resistance, etc. Whether in static sealing or dynamic sealing applications, it can meet product requirements and is comparable to traditional rubber sealing rings.
[0042] The present application also provides a method for preparing the above-mentioned UV adhesive for sealing gaskets that can be cured on site, which comprises the following steps: Weigh the acrylate prepolymer, the first acrylate active monomer, the crosslinking agent, the photoinitiator and the thixotropic agent according to weight, stir at 40-50° C. and 1200-1500 r / min for 0.5-1 h until the mixture is uniformly mixed to obtain a mixed solution; Weigh the mercaptan-modified prepolymer according to weight, add it to the mixed solution, stir at a speed of 1200-1500 r / min for 30-40 min, and mix evenly; Then vacuum, filter and package to obtain the sealing gasket UV glue that can be cured on site.
[0043] The present application also provides a sealing gasket product, wherein the sealing gasket product is prepared by the sealing gasket UV glue that can be cured on site as described above. In the present application, the provided sealing gasket UV glue that can be cured on site can be used to prepare sealing gasket products of various shapes, and can be sealed according to actual needs, perfectly making up for the shortcomings of traditional sealing processes, and also having good rework performance, which can save material costs and improve production efficiency.
[0044] Reference Figure 1 (Step S1 is not Figure 1 As shown in the figure), the present application also provides a method for preparing the sealing gasket product as described above, which comprises the following steps: S1, select ultraviolet curing light source 3; S2, using manual dispensing or an automated dispensing machine 1, extrude the sealing gasket UV glue 2 that can be cured on site into a fixed shape and thickness; S3, using the ultraviolet curing light source 3 to irradiate and cure the sealing gasket UV glue 2 that can be cured on site, to obtain a sealing gasket product.
[0045] Among them, a glue groove that meets the use requirements can be set first, and then the sealing gasket UV glue 2 that can be cured on site can be dispensed into the glue groove. The ultraviolet curing light source 3 can be selected with a suitable power, which can irradiate and cure the sealing gasket UV glue 2 that can be cured on site, and specifically, an LED ultraviolet curing light source 3 with a wavelength of 365nm can be used.
[0046] The technology for making sealing gasket products provided in this application is suitable for on-site construction, has an automated process, can be designed in special shapes, has fast forming, and has high production efficiency. This type of sealing gasket production method is gradually becoming the first choice in many industries.
[0047] The invention is further described below by means of specific examples.
[0048] Some of the raw materials in the examples are from the following sources: Polyurethane acrylate: Sartomer CN966H90 NS; Alkoxylated nonylphenol acrylate: Sartomer SR614 NS; Polyethylene glycol dimethacrylate: Sartomer SR603 OP; Thixotropic agent: Degussa R202.
[0049] Example 1 The method for preparing the mercaptan-modified prepolymer of Example 1 comprises the following steps: In a reaction container, add a certain amount of 1,6-hexanedithiol, then add the catalyst dimethylphenylphosphine, and then add 1,4-butanediol diacrylate dropwise under nitrogen protection; After the addition is complete, the temperature is raised to 65°C and the reaction is continued for 5 hours until the C=C double bond content is below 0.1%; The temperature was lowered to room temperature to obtain the thiol-modified prepolymer of Example 1.
[0050] The amount of dimethylphenylphosphine added is 0.1% of the total weight of the thiol-modified prepolymer; the molar ratio of 1,6-hexanediol to 1,4-butanediol diacrylate is 2:1, and the dropping speed is controlled to keep the temperature of the reaction material below 30°C.
[0051] The UV adhesive for sealing gaskets that can be cured on site in Example 1 comprises the following components in parts by mass: 50 parts of polyurethane acrylate, 25 parts of thiol-modified prepolymer, 6 parts of hydroxyethyl acrylate, 12 parts of alkoxylated nonylphenol acrylate, 1 part of polyethylene glycol dimethacrylate, 2 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 3 parts of thixotropic agent.
[0052] Weigh polyurethane acrylate, hydroxyethyl acrylate, alkoxylated nonylphenol acrylate, polyethylene glycol dimethacrylate, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and thixotropic agent according to weight, stir at 45°C and 1500 r / min for 1 hour until the mixture is uniformly mixed to obtain a mixed solution; Weigh the mercaptan-modified prepolymer according to weight, add it to the mixed solution, stir at 1500 r / min for 30 min, and mix well; Then vacuumize, filter and package to obtain the sealing gasket UV glue that can be cured on site in Example 1.
[0053] The basic properties of the UV adhesive for sealing gaskets that can be cured on site in Example 1 are shown in Table 1: Table 1 Appearance Colorless turbid liquid Viscosity 32000-35000cps (25℃) Shore Hardness 5A (GB / T 2411-2008) The sealing gasket UV adhesive curable on site of Example 1 is prepared into a sealing gasket product, comprising the following steps: Select an LED ultraviolet curing light source with a power of 48w and a wavelength of 365nm; Using an automated glue dispensing machine, extrude the UV glue for sealing gaskets that can be cured on site in Example 1 into a fixed shape and thickness; The sealing gasket product of Example 1 was obtained by irradiating and curing with a selected ultraviolet curing light source for 2 minutes.
[0054] The performance data of the sealing gasket product prepared in Example 1 are shown in Table 2: Table 2 Product size 5cm*0.5cm*0.5cm Radiation Intensity <![CDATA[1600mj / cm 2 ]]> Curing time 2min Volume shrinkage 0.4% (GB / T 24148.9-2014) Shore Hardness 5A (GB / T 2411-2008) Elongation at break 850% (GB / T 528) Elastic modulus 3MPa (HG / T3321-2012)
[0055] Example 2 The method for preparing the mercaptan-modified prepolymer of Example 2 comprises the following steps: In a reaction container, add a certain amount of 1,6-hexanedithiol, then add a catalyst, and then dropwise add 1,4-butanediol diacrylate under nitrogen protection; After the addition is complete, the temperature is raised to 65°C and the reaction is continued for 5 hours until the C=C double bond content is below 0.1%; The temperature was lowered to room temperature to obtain the thiol-modified prepolymer of Example 2.
[0056] The amount of dimethylphenylphosphine added is 0.1% of the total weight of the mercaptan-modified prepolymer; the molar ratio of 1,6-hexanedithiol to 1,4-butanediol diacrylate is 2: 1, and the dropwise addition rate is controlled to keep the temperature of the reaction material below 30° C. The field-curable sealing gasket UV adhesive of Example 2 includes the following components in terms of mass fraction: 50 parts of polyurethane acrylate, 23 parts of thiol-modified prepolymer, 9 parts of hydroxyethyl acrylate, 9 parts of alkoxylated nonylphenol acrylate, 1 part of polyethylene glycol dimethacrylate, 2 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 5 parts of thixotropic agent.
[0057] Weigh polyurethane acrylate, hydroxyethyl acrylate, alkoxylated nonylphenol acrylate, polyethylene glycol dimethacrylate, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and thixotropic agent according to weight, stir at 45°C and 1500 r / min for 1 hour until the mixture is uniformly mixed to obtain a mixed solution; Weigh the mercaptan-modified prepolymer according to weight, add it to the mixed solution, stir at 1500 r / min for 30 min, and mix well; Then vacuumize, filter and package to obtain the sealing gasket UV glue that can be cured on site in Example 2.
[0058] The basic properties of the UV adhesive for sealing gaskets that can be cured on site in Example 2 are shown in Table 3: Table 3 Appearance Colorless turbid liquid Viscosity 40000-50000cps (25℃) Shore Hardness 8A (GB / T 2411-2008) The sealing gasket UV adhesive curable on site of Example 2 is prepared into a sealing gasket product, comprising the following steps: Select an LED ultraviolet curing light source with a power of 48w and a wavelength of 365nm; Using an automated dispensing machine, extrude the UV glue for sealing gaskets that can be cured on site in Example 2 into a fixed shape and thickness; The sealing gasket product of Example 2 is obtained by irradiating and curing with a selected ultraviolet curing light source for 2 minutes.
[0059] The performance data of the sealing gasket product prepared in Example 2 is shown in Table 4: Table 4 Product size 5cm*0.5cm*0.5cm Radiation Intensity <![CDATA[1600mj / cm 2 ]]> Curing time 2min Volume shrinkage 0.5% (GB / T 24148.9-2014) Shore Hardness 8A (GB / T 2411-2008) Elongation at break 530% (GB / T 528) Elastic modulus 6.4MPa (HG / T3321-2012) The embodiments of the present application use thiol-modified prepolymers, preferably other materials according to the required performance of the sealing gasket product, and reasonably match the dosage of each component to achieve a relatively balanced comprehensive effect of the elastic modulus and elongation of the sealing gasket product. By using ultraviolet radiation curing, sealing gasket products with performance comparable to traditional rubber sealing rings can be obtained, which can greatly improve production efficiency and expand industrial applications.
[0060] It should be understood that the application of the present application is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made according to the above description, and all these improvements and changes should fall within the scope of protection of the present application.
Claims
1. A UV adhesive for sealing gaskets that can be cured on site, characterized in that: According to weight parts, it includes the following components: 40-70 parts of acrylate prepolymer, 10-30 parts of thiol-modified prepolymer, 10-30 parts of first acrylate active monomer, 1-3 parts of crosslinking agent, 1-3 parts of photoinitiator, 3-5 parts of thixotropic agent; The thiol-modified prepolymer is prepared by Michael addition reaction of thiol and a second acrylate active monomer.
2. The UV adhesive for sealing gaskets curable on site according to claim 1, characterized in that: The method for preparing the mercaptan-modified prepolymer comprises the following steps: In a reaction container, a quantitative amount of the mercaptan and a catalyst are added, and the second acrylic ester active monomer is added dropwise under nitrogen protection; After the addition is complete, the temperature is raised to 60-70°C and the reaction is continued for 5 hours until the C=C double bond content is below 0.1%; Lowering the temperature to room temperature to obtain the thiol-modified prepolymer; The molar ratio of the total amount of SH bonds of the added thiol to the total amount of double bonds of the added second acrylic ester reactive monomer is (2-2.05):1; During the dropping process, the temperature of the reaction material is kept below 30° C. by controlling the dropping speed; the thiol is one or more of 1,6-hexanedithiol, trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, and 2,2-bis(mercaptomethyl)-1,3-propyldithiol; The second acrylate active monomer is one or more of 2-phenoxyethyl methacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,4-butanediol diacrylate and caprolactone acrylate; The catalyst is dimethylphenylphosphine, and the added amount of the catalyst is 0.1% of the total weight of the mercaptan-modified prepolymer.
3. The UV adhesive for sealing gaskets curable on site according to claim 2, characterized in that: The thiol is 1,6-hexanedithiol; The second acrylic ester active monomer is 1,4-butanediol diacrylate.
4. The UV adhesive for sealing gaskets curable on site according to claim 1, characterized in that: The acrylate prepolymer is one or more of epoxy acrylate, polyurethane acrylate, polyether acrylate and polyester acrylate; The first acrylic acid ester active monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkoxylated nonylphenol acrylate, ethoxyethoxyethyl acrylate, alkoxydodecyl acrylate and caprolactone acrylate; The crosslinking agent is one or more of ethoxylated bisphenol A diacrylate, ethoxylated pentaerythritol tetraacrylate, polyethylene glycol dimethacrylate and ethoxylated trimethylolpropane triacrylate; The photoinitiator is a combination of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the mass ratio of the 1-hydroxycyclohexyl phenyl ketone to 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is 2:1; The thixotropic agent is fumed silica.
5. The UV adhesive for sealing gaskets curable on site according to claim 4, characterized in that: The acrylate prepolymer is one or two of the polyurethane acrylate and the polyether acrylate, the acrylate prepolymer has a molecular weight of 10000-15000, and a double bond functionality of 1-2.
6. The UV adhesive for sealing gaskets curable on site according to claim 4, characterized in that: The first acrylic ester active monomer is a combination of hydroxyethyl acrylate and alkoxylated nonylphenol acrylate, and the mass ratio of the hydroxyethyl acrylate to the alkoxylated nonylphenol acrylate is 1:(1-2).
7. The UV adhesive for sealing gaskets curable on site according to claim 4, characterized in that: The cross-linking agent is polyethylene glycol dimethacrylate.
8. A method for preparing the UV adhesive for sealing gaskets that can be cured on site as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Weigh the acrylate prepolymer, the first acrylate active monomer, the crosslinking agent, the photoinitiator and the thixotropic agent according to weight, and stir at a temperature of 40-50° C. and a speed of 1200-1500 r / min for 0.5-1 h until the mixture is uniformly mixed to obtain a mixed solution; Weigh the mercaptan-modified prepolymer according to weight, add it to the mixed solution, stir at a speed of 1200-1500 r / min for 30-40 min, and mix evenly; Then vacuuming, filtering and packaging are performed to obtain the sealing gasket UV glue that can be cured on site.
9. A sealing gasket product, characterized in that: The sealing gasket product is made of the sealing gasket UV glue that can be cured on site as described in any one of claims 1 to 7.
10. A method for preparing a sealing gasket product according to claim 9, characterized in that: The following steps are involved: Select UV curing light source; Using manual dispensing or an automated dispensing machine, the UV glue for the sealing gasket that can be cured on site is extruded into a fixed shape and thickness; The sealing gasket UV glue that can be cured on site is irradiated and cured by an ultraviolet curing light source to obtain the sealing gasket product.