Photo-curing adhesive, bonding method, epoxy modified polyether amide and preparation method of epoxy modified polyether amide

Abstract

The invention relates to a photocuring adhesive, a bonding method, epoxy modified polyether amide and a preparation method thereof. The photocuring adhesive is prepared from the following components in parts by weight: 40 to 80 parts of epoxy resin, 10 to 40 parts of epoxy modified polyether amide and 1 to 5 parts of cationic photoinitiator, wherein the preparation raw materials of the epoxy modified polyether amide comprise an amino-terminated polyether amide block copolymer and an epoxy compound, the amino-terminated polyether amide block copolymer comprises a polyether segment and a polyamide segment, and the polyamide segment comprises at least one of an alicyclic polyamide segment, a wholly aromatic polyamide segment and a semi-aromatic polyamide segment. The epoxy compound includes a polyfunctional alicyclic epoxy compound. The photocuring adhesive can be used for bonding optical lenses, and high light transmittance and high-temperature and high-humidity resistance are ensured while the impact resistance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of adhesives, in particular to a photocurable adhesive, a bonding method, an epoxy-modified polyetheramide and a preparation method thereof. BACKGROUND

[0002] Optical adhesives are special adhesives used for bonding, sealing or protecting optical elements such as lenses, prisms, optical fibers, optical sensors, etc. They need to have excellent optical properties while ensuring high bonding strength and adapt to complex environmental conditions. For example, in the AR / VR optical application field represented by optical waveguide technology, due to the bonding of multi-layer optical prisms and lenses, the performance requirements of the adhesive are more demanding, such as a transmittance of more than 98%, and the ability to maintain good bonding and protection effects under high temperature and humidity conditions.

[0003] Traditional photocurable optical adhesives mainly include photocurable epoxy adhesives and photocurable acrylic adhesives. The photocurable acrylic ester system is a free radical photopolymerization, which has the disadvantages of strong monomer odor, large shrinkage after curing, and weak adhesion than epoxy systems. Photocurable epoxy adhesives usually use epoxy resin as the main body for cationic photopolymerization, and have good adhesion and heat resistance, and high transparency, but due to the large rigidity of the crosslinked network, the material has large brittleness, poor impact resistance and toughness, and often needs to be toughened. However, traditional toughening modification will lead to a decrease in the transmittance and high temperature and humidity resistance of the cured material, limiting its application in high transmittance, high adhesion and high durability scenarios.

[0004] Therefore, it is urgent to develop a photocurable adhesive that can be used for bonding optical elements, which can improve impact resistance while ensuring high transmittance and high temperature and humidity resistance. SUMMARY

[0005] Based on this, some embodiments of the present application provide a photocurable adhesive that can be used for bonding optical elements, which can improve impact resistance while ensuring high transmittance and high temperature and humidity resistance.

[0006] In addition, some other embodiments of the present application also provide a bonding method for optical elements, an epoxy-modified polyetheramide and a preparation method thereof.

[0007] A photocurable adhesive, by weight fraction, includes: 40-80 parts of epoxy resin, 10-40 parts of epoxy-modified polyetheramide and 1-5 parts of cationic photoinitiator.

[0008] The raw materials for preparing the epoxy-modified polyether amide include an amino-terminated polyether amide block copolymer and an epoxy compound. The amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment. The polyamide segment includes at least one of an alicyclic polyamide segment, a fully aromatic polyamide segment, and a semi-aromatic polyamide segment. The epoxy compound includes a multifunctional alicyclic epoxy compound.

[0009] In some embodiments, the polyamide segment includes an alicyclic polyamide segment.

[0010] In some embodiments, the raw materials for preparing the polyamide segment include an aliphatic dicarboxylic acid and an alicyclic diamine in a molar ratio of (1.02~1.06):1.

[0011] In some embodiments, the aliphatic dicarboxylic acid is C4~C6. 14 Aliphatic dicarboxylic acids.

[0012] In some embodiments, the aliphatic dicarboxylic acid includes one or more of adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, and tetradecanoic acid.

[0013] In some embodiments, the alicyclic diamine includes one or more of 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-phenylenediamine, and norbornenediamine.

[0014] In some embodiments, the alicyclic diamine includes one or more of 4,4'-diaminodicyclohexylmethane and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0015] In some embodiments, the raw materials for preparing the polyamide include alicyclic dicarboxylic acids and aliphatic diamines in a molar ratio of (1.02~1.06):1.

[0016] In some embodiments, the alicyclic dicarboxylic acid includes one or more of 1,2-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and hydrogenated phthalic acid.

[0017] In some embodiments, the aliphatic diamine includes one or more of hexamethylenediamine, nonanediamine, decanediamine, and dodecanediamine.

[0018] In some embodiments, the raw materials for preparing the amino-terminated polyether amide block copolymer include polyether polyol, polyamide, and a capping agent, wherein the end group of the polyamide is a carboxyl group, and in the amino-terminated polyether amide block copolymer, the polyether segment and the polyamide segment are connected by an ester bond.

[0019] In some embodiments, the polyether polyol includes one or more of polyethylene glycol, polypropylene glycol, and polybutanediol.

[0020] In some embodiments, the capping agent includes one or more of aliphatic diamines and alicyclic diamines.

[0021] In some embodiments, the capping agent includes one or more of hexamethylenediamine, nonanediamine, decanediamine, dodecanediamine, 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-phenylenediamine, and norbornenediamine.

[0022] In some embodiments, the capping agent includes one or more of hexamethylenediamine, decanediamine, 4,4'-diaminodicyclohexylmethane, and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0023] In some embodiments, the molar ratio of the polyamide to the polyether polyol is 1:1.

[0024] In some embodiments, the molar amount of the capping agent is 0.1% to 1% of the total molar amount of the polyether polyol and the polyamide.

[0025] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of less than 20,000.

[0026] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of less than 10,000.

[0027] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of 3000-8000.

[0028] In some embodiments, the epoxy compound contains an epoxycyclohexyl group.

[0029] In some embodiments, the epoxy compound includes one or more of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 3,4-epoxycyclohexylmethyl-2′,3′-epoxycyclohexyl ether.

[0030] In some embodiments, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:(4 / n), where n is the number of epoxy groups in the epoxy compound.

[0031] In some embodiments, the epoxy resin includes one or more of alicyclic epoxy resins, hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, and hydrogenated phenolic epoxy resins.

[0032] In some embodiments, the cationic photoinitiator includes one or more of diazonium salts, diaryliodomonium salts, triarylthionium salts, alkylthionium salts, iron aromatic salts, sulfonyloxy ketones, and triarylsiloxanes.

[0033] In some embodiments, the cationic photoinitiator includes one or more of the following: n-6-isopropylbenzeneferrocene hexafluorophosphate, 1-hydroxycyclohexylphenyl ketone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, methyl benzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-isopropylthioxanthrone, benzoin dimethyl ether, dimethylbenzoyl ketal, and benzophenone.

[0034] In some embodiments, the weight ratio of the epoxy resin to the epoxy-modified polyether amide is (2~4):1.

[0035] In some embodiments, the weight ratio of the epoxy resin to the cationic photoinitiator is (16~40):1.

[0036] In some embodiments, the photocurable adhesive further includes one or more of the following: 1 to 20 parts of an accelerator, 1 to 20 parts of an reactive diluent, 1 to 15 parts of a thixotropic modifier, 1 to 5 parts of a coupling agent, and 1 to 5 parts of a functional additive.

[0037] In some embodiments, the promoter comprises an oxetane monomer.

[0038] In some embodiments, the reactive diluent includes butyl glycidyl ether, neodecanoic acid glycidyl ether, C 12 ~C 14 One or more of alkyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0039] In some embodiments, the thixotropic modifier comprises fumed silica.

[0040] In some embodiments, the coupling agent includes one or more of γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane.

[0041] In some embodiments, the functional additives include one or more of leveling agents and antioxidants.

[0042] A method for bonding optical elements, comprising the following steps:

[0043] The optical element is bonded using a light-curing adhesive, wherein the light-curing adhesive is the aforementioned light-curing adhesive.

[0044] In some embodiments, the optical element includes one or more of a lens, a prism, an optical fiber, and a sensor.

[0045] In some embodiments, the optical element is made of one or more of glass, polycarbonate, polymethyl methacrylate, nylon, cyclic olefin copolymers, cyclic olefin homopolymers, and silicon carbide.

[0046] An epoxy-modified polyether amide, wherein the raw materials for preparing the epoxy-modified polyether amide include an amino-terminated polyether amide block copolymer and an epoxy compound, wherein the amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment, wherein the polyamide segment includes at least one of an alicyclic polyamide segment, a fully aromatic polyamide segment, and a semi-aromatic polyamide segment, and wherein the epoxy compound includes a multifunctional alicyclic epoxy compound.

[0047] In some embodiments, the polyamide segment includes an alicyclic polyamide segment.

[0048] In some embodiments, the raw materials for preparing the polyamide segment include an aliphatic diacid and an alicyclic diamine in a molar ratio of (1.02~1.06):1, or the raw materials for preparing the polyamide include an alicyclic diacid and an aliphatic diamine in a molar ratio of (1.02~1.06):1.

[0049] In some embodiments, in the amino-terminated polyether amide block copolymer, the polyether segment is connected to the polyamide segment via an ester bond.

[0050] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of less than 20,000.

[0051] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of less than 10,000.

[0052] In some embodiments, the amino-terminated polyether amide block copolymer has a weight-average molecular weight of 3000-8000.

[0053] In some embodiments, the epoxy compound contains an epoxycyclohexyl group.

[0054] In some embodiments, the epoxy compound includes one or more of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 3,4-epoxycyclohexylmethyl-2′,3′-epoxycyclohexyl ether.

[0055] In some embodiments, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:(4 / n), where n is the number of epoxy groups in the epoxy compound.

[0056] A method for preparing epoxy-modified polyether amide includes the following steps:

[0057] The epoxy-modified polyether amide block copolymer is prepared by reacting an amino-terminated polyether amide block copolymer with an epoxy compound.

[0058] The amino-terminated polyether amide block copolymer comprises a polyether segment and a polyamide segment, wherein the polyamide segment comprises at least one of an alicyclic polyamide segment, a fully aromatic polyamide segment, and a semi-aromatic polyamide segment, and the epoxy compound comprises a multifunctional alicyclic epoxy compound.

[0059] In some embodiments, the reaction temperature is 40°C to 60°C and the reaction time is 4h to 6h in the step of reacting the amino-terminated polyether amide block copolymer with the epoxy compound.

[0060] In some embodiments, the amino-terminated polyether amide block copolymer is prepared by the following steps: under the action of a catalyst and a protective atmosphere, polyamide, polyether polyol and capping agent are mixed and reacted at 240°C to 300°C for 6 to 8 hours, wherein the end group of the polyamide is a carboxyl group.

[0061] In some embodiments, the polyamide is prepared by the following steps: under a protective atmosphere, a diacid and a diamine are reacted at 160°C to 240°C for 2 to 4 hours, wherein at least one of the diacid and the diamine is alicyclic or aromatic and the molar ratio is (1.02 to 1.06):1.

[0062] The photocurable adhesive of some embodiments of this application includes a certain proportion of epoxy resin, epoxy-modified polyether amide, and cationic photoinitiator. The raw materials for preparing the epoxy-modified polyether amide include amino-terminated polyether amide block copolymers and epoxy compounds. The epoxy groups contained therein can undergo cationic photocuring, thereby linking the polyether amide segments to the epoxy resin and improving its resistance to damp heat. Furthermore, the epoxy-modified polyether amide contains a large number of aliphatic or aromatic ring structures, which greatly improves the light transmittance of the cured product. The flexible polyether segments and polar polyamide segments give the cured product of the photocurable adhesive excellent flexibility, impact resistance, high adhesion, and high resistance to damp heat. Therefore, the above-mentioned photocurable adhesive can be used for bonding optical components, exhibiting excellent light transmittance, adhesion, and high-temperature and high-humidity reliability. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0064] Figure 1 This is a schematic diagram of a process flow diagram for preparing epoxy-modified polyether amide according to some embodiments of this application. Detailed Implementation

[0065] To facilitate understanding of this application, a more comprehensive description of the application will be provided below in conjunction with specific embodiments. Preferred embodiments of the application are given in the specific embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0067] Unless otherwise stated or in case of conflict, the terms or phrases used in this application shall have the following meanings:

[0068] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features.

[0069] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0070] In this application, "one or more" refers to any one, two, or more of the listed items. "Multiple" refers to any two or more of the listed items.

[0071] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0072] In this application, terms such as "further," "even more," "particularly," "for example," "like," "example," and "exemplary" are used for descriptive purposes to indicate a connection in the coverage of different technical solutions presented earlier and later, but should not be construed as limiting the preceding technical solution or restricting the scope of protection herein. Unless otherwise specified herein, A (e.g., B) indicates that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0073] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "present" or "absent." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain." "Optional component X" indicates whether component X exists or does not exist, or whether component X is contained or not.

[0074] When a numerical range is disclosed in this application, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed in this application should be understood to include any and all subranges to which they are included.

[0075] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0076] The terms "comprising" and "having," and any variations thereof, used in the embodiments of this application, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to such processes, methods, products, or devices.

[0077] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0078] In the flowchart of this application, although the steps are shown sequentially according to the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps. They can be executed in other orders. Moreover, at least some of the steps in the diagram may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. Their execution order is not necessarily sequential, but can be performed alternately or in turn with at least some of other steps or other sub-steps or stages.

[0079] The first aspect of this application provides an epoxy-modified polyether amide, wherein the raw materials for preparing the epoxy-modified polyether amide include an amino-terminated polyether amide block copolymer and an epoxy compound. The amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment. The polyamide segment includes at least one of an alicyclic polyamide segment, a fully aromatic polyamide segment, and a semi-aromatic polyamide segment. The epoxy compound includes a multifunctional alicyclic epoxy compound.

[0080] The raw materials for preparing the aforementioned epoxy-modified polyether amide include amino-terminated polyether amide block copolymers and epoxy compounds. The epoxy groups contained within can undergo cationic photocuring. When used in photocurable adhesives, this allows the polyether amide segments to be linked to the epoxy resin, improving resistance to damp heat. Furthermore, the epoxy-modified polyether amide contains a large number of aliphatic or aromatic ring structures, significantly increasing the light transmittance of the cured product. The flexible polyether segments and polar polyamide segments give the cured product excellent flexibility, impact resistance, high adhesion, and high resistance to damp heat. Without the addition of epoxy compounds, the polyether amide can only be cured by heating. It cannot cure during the photocuring process of optical adhesives, resulting in weak bonding with the epoxy resin matrix. It is prone to failure in humid and hot environments, reducing adhesive strength and causing the photocurable adhesive to lose its toughening effect.

[0081] In this application, alicyclic polyamides refer to a class of polyamides whose main chain contains alicyclic structural units (non-aromatic cyclic structures). The raw materials for preparing alicyclic polyamides include diamines and diacids, where at least one of the diamine and diacid is alicyclic. For example, the diamine is an alicyclic diamine and the diacid is an aliphatic diacid; or, the diamine is an aliphatic diamine and the diacid is an alicyclic diacid; or, the diamine is an alicyclic diamine and the diacid is also an alicyclic diacid.

[0082] Semi-aromatic polyamides refer to polyamides whose main chain contains both aromatic rings and aliphatic chains (or aliphatic rings), linked by amide bonds. Specifically, the raw materials for preparing semi-aromatic polyamides include diamines and diacids, where one of the diamines and diacids is aromatic and the other is aliphatic or alicyclic.

[0083] Fully aromatic polyamides refer to polyamides whose main chain consists entirely of aromatic rings and amide bonds. Specifically, the raw materials for preparing aromatic polyamides include diamines and diacids, both of which are aromatic.

[0084] Alicyclic polyamides, fully aromatic polyamides, or semi-aromatic polyamides, compared to aliphatic polyamides, exhibit higher light transmittance when used in UV-curable adhesives. Optionally, in some embodiments, the polyamide segment includes alicyclic polyamides. Fully aromatic or semi-aromatic polyamides, compared to alicyclic polyamides, exhibit slightly lower yellowing resistance when used in UV-curable adhesives. Therefore, from the perspective of further optimizing yellowing resistance, the polyamide segment preferably includes an alicyclic polyamide segment. It is understood that in other embodiments, if the requirement for yellowing resistance in the UV-curable adhesive is not high, fully aromatic or semi-aromatic polyamides can also be selected.

[0085] In some embodiments, the raw materials for preparing the polyamide segment include a diacid and a diamine in a molar ratio of (1.02~1.06):1. By using an excess of diacid, the polyamide end groups are capped with carboxyl groups, allowing it to subsequently react with the hydroxyl groups in the polyether polyol to obtain a block copolymer.

[0086] In some embodiments, the raw materials for preparing the polyamide segment include an aliphatic diacid and an alicyclic diamine in a molar ratio of (1.02~1.06):1. For example, the molar ratio of the aliphatic diacid and the alicyclic diamine may be, but is not limited to, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, or any range of two of these values. Optionally, the molar ratio of the aliphatic diacid and the alicyclic diamine is (1.02~1.04):1.

[0087] Specifically, aliphatic dicarboxylic acids are C4~C6. 14 Aliphatic dicarboxylic acids. In some embodiments, the aliphatic dicarboxylic acids include one or more of adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, and tetradecanoic acid.

[0088] Specifically, the alicyclic diamines include one or more of 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-phenylenediamine, and norbornenediamine. In some embodiments, the alicyclic diamines include one or more of 4,4'-diaminodicyclohexylmethane and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0089] In other embodiments, the raw materials for preparing the polyamide segment include alicyclic dicarboxylic acids and aliphatic diamines in a molar ratio of (1.02~1.06):1.

[0090] Optionally, the alicyclic dicarboxylic acid includes one or more of 1,2-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and hydrogenated phthalic acid. The alicyclic diamine includes one or more of hexamethylenediamine, nonanediamine, decanediamine, and dodecanediamine.

[0091] In some embodiments, the raw materials for preparing the amino-terminated polyether amide block copolymer include polyether polyol, polyamide, and a capping agent. The end group of the polyamide is a carboxyl group. In the amino-terminated polyether amide block copolymer, the polyether segment and the polyamide segment are connected by an ester bond.

[0092] Specifically, polyether polyols include one or more of polyethylene glycol, polypropylene glycol, and polybutanediol.

[0093] Specifically, the weight-average molecular weight of polyether polyols is 500 to 3000.

[0094] Specifically, the weight-average molecular weight of polyamide is 500 to 10,000.

[0095] Specifically, the weight-average molecular weight of the amino-terminated polyether amide block copolymer is less than 20,000. Optionally, the weight-average molecular weight of the amino-terminated polyether amide block copolymer is less than 10,000. Optionally, the weight-average molecular weight of the amino-terminated polyether amide block copolymer is 3,000 to 8,000.

[0096] Specifically, the molar ratio of polyamide to polyether polyol is 1:1. This means that the carboxyl groups in the polyamide react with the hydroxyl groups in the polyether polyol, resulting in a 1:1 molar ratio. In practice, the molar ratio can fluctuate within a certain error range, for example, ±5%, meaning the molar ratio of polyamide to polyether polyol fluctuates within the range of 1:(0.95~1.05).

[0097] Specifically, the end-capping agent includes one or more of aliphatic and alicyclic diamines. Specifically, the end-capping agent includes one or more of hexamethylenediamine, nonanediamine, decanediamine, dodecanediamine, 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-phenylenediamine, and norbornenediamine. In some embodiments, the end-capping agent includes one or more of hexamethylenediamine, decanediamine, 4,4'-diaminodicyclohexylmethane, and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0098] In some embodiments, the molar amount of the capping agent is 0.1% to 1% of the total molar amount of the polyether polyol and polyamide. For example, the percentage of the molar amount of the capping agent to the total molar amount of the polyether polyol and polyamide may be, but is not limited to, 0.1%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, or any combination of these values.

[0099] In some embodiments, the raw materials for preparing the amino-terminated polyether amide block copolymer further include a catalyst. Specifically, the catalyst includes one or more selected from phosphoric acid, phosphates, titanates, and zirconates. Optionally, the catalyst includes one or more selected from phosphoric acid, sodium phosphite, and tetrabutyl zirconate.

[0100] In some embodiments, the molar amount of catalyst is 0.01% to 0.1% of the total molar amount of polyether polyol and polyamide. For example, the percentage of the molar amount of catalyst to the total molar amount of polyether polyol and polyamide may be, but is not limited to, 0.01%, 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, or any combination of these values.

[0101] In some embodiments, in a multifunctional alicyclic epoxy compound, multifunctionality means that the number of epoxy groups is multiple. Specifically, a multifunctional alicyclic epoxy compound refers to an alicyclic epoxy compound with two or more epoxy groups.

[0102] In some embodiments, the epoxy compound contains an epoxycyclohexyl group. Specifically, the epoxy compound includes one or more of difunctional cyclohexyl-containing epoxy compounds and trifunctional cyclohexyl-containing epoxides. Optionally, the epoxy compound includes a difunctional cyclohexyl-containing epoxy compound. In some embodiments, the epoxy compound includes one or more of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 3,4-epoxycyclohexylmethyl-2′,3′-epoxycyclohexyl ether. The above epoxy compounds enable cationic photocuring reactions.

[0103] In some embodiments, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:(4 / n), where n is the number of epoxy groups in the epoxy compound. n is an integer, such as 2, 3, 4, etc. For example, if the epoxy compound contains two epoxy groups, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:2; or if the epoxy compound contains four epoxy groups, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:1. It can be understood that a molar ratio of 1:(4 / n) for the amino-terminated polyether amide block copolymer to the epoxy compound means that the amino-terminated polyether amide block copolymer has two amino groups and four active hydrogen groups, which can react with four epoxy groups. Therefore, the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:(4 / n). In practice, the molar ratio can fluctuate within a certain error range, for example, ±5%.

[0104] A second aspect of this application provides a method for preparing epoxy-modified polyether amide, comprising the following steps:

[0105] An epoxy-modified polyether amide block copolymer was prepared by reacting an amino-terminated polyether amide block copolymer with an epoxy compound.

[0106] The amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment. The polyamide segment includes at least one of an alicyclic polyamide segment, a fully aromatic polyamide segment, and a semi-aromatic polyamide segment. The epoxy compound includes a multifunctional alicyclic epoxy compound.

[0107] In some embodiments, in the step of reacting the amino-terminated polyetheramide block copolymer with the epoxy compound, the reaction temperature is 40°C to 60°C, and the reaction time is 4h to 6h. For example, the reaction temperature of the amino-terminated polyetheramide block copolymer with the epoxy compound can be, but is not limited to, 40°C, 42°C, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C, or any combination thereof. The reaction time can be, but is not limited to, 4h, 4.5h, 5h, 5.5h, 6h, or any combination thereof.

[0108] Specifically, the specific substances of the epoxy compound and its molar ratio with the amino-terminated polyether amide block copolymer are the same as those in the first aspect mentioned above, and will not be repeated here.

[0109] In some embodiments, the amino-terminated polyether amide block copolymer is prepared by the following steps: polyamide, polyether polyol, and a capping agent are mixed under the action of a catalyst and a protective atmosphere, and reacted at 240°C to 300°C for 6 to 8 hours, wherein the end groups of the polyamide are carboxyl groups. For example, the reaction temperature of the polyamide, polyether polyol, and capping agent can be, but is not limited to, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, or any combination thereof. The reaction time can be, but is not limited to, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, or any combination thereof.

[0110] Specifically, the composition and dosage ratio of the polyether polyol, end-capping agent, and catalyst are the same as those in the first aspect mentioned above, and will not be repeated here.

[0111] In some embodiments, the polyamide is prepared by the following steps: reacting a diacid with a diamine at 160°C to 240°C for 2 to 4 hours under a protective atmosphere, wherein at least one of the diacid and the diamine is alicyclic or aromatic, and the molar ratio is (1.02 to 1.06):1. For example, the reaction temperature of the diacid with the diamine can be, but is not limited to, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, or any combination thereof. The reaction time can be, but is not limited to, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, or any combination thereof.

[0112] Specifically, the composition and dosage ratio of the dicarboxylic acid and diamine are the same as those in the first aspect mentioned above, and will not be repeated here.

[0113] Specifically, in some embodiments, please refer to Figure 1 The preparation method of epoxy-modified polyether amide includes the following steps:

[0114] Step S110: Under a protective atmosphere, a diacid and a diamine are reacted at 160℃~240℃ for 2h~4h to prepare polyamide. At least one of the diacid and the diamine is alicyclic or aromatic and the molar ratio is (1.02~1.06):1.

[0115] Step S120: Under the action of a catalyst and a protective atmosphere, polyamide, polyether polyol and capping agent are mixed and reacted at 240℃~300℃ for 6h~8h to prepare amino-capped polyether amide block copolymer.

[0116] Step S130: React the amino-terminated polyether amide block copolymer and the epoxy compound at 40℃~60℃ for 4h~6h to prepare epoxy-modified polyether amide.

[0117] The third aspect of this application provides a photocurable adhesive, comprising, by weight parts: 40 to 80 parts of epoxy resin, 10 to 40 parts of epoxy-modified polyether amide block copolymer, and 1 to 5 parts of cationic photoinitiator;

[0118] The raw materials for preparing epoxy-modified polyether amide include amino-terminated polyether amide block copolymers and epoxy compounds. The amino-terminated polyether amide block copolymers include polyether segments and polyamide segments. The polyamide segments include at least one of alicyclic polyamide segments, fully aromatic polyamide segments, and semi-aromatic polyamide segments. The epoxy compounds include multifunctional alicyclic epoxy compounds.

[0119] The photocurable adhesive of some embodiments of this application includes a certain proportion of epoxy resin, epoxy-modified polyether amide, and cationic photoinitiator. The raw materials for preparing the epoxy-modified polyether amide include amino-terminated polyether amide block copolymers and epoxy compounds. The epoxy groups contained therein can undergo cationic photocuring, thereby linking the polyether amide segments to the epoxy resin and improving its resistance to damp heat. Furthermore, the epoxy-modified polyether amide contains a large number of aliphatic or aromatic ring structures, which greatly improves the light transmittance of the cured product. The flexible polyether segments and polar polyamide segments give the cured product of the photocurable adhesive excellent flexibility, impact resistance, high adhesion, and high resistance to damp heat. Therefore, the above-mentioned photocurable adhesive can be used for bonding optical components, exhibiting excellent light transmittance, adhesion, and high-temperature and high-humidity reliability.

[0120] Specifically, the preparation of epoxy-modified polyether amide is the same as described above, and will not be repeated here.

[0121] In some embodiments, the epoxy-modified polyether amide is present in the UV-curable adhesive in the amount of 10 to 40 parts by weight. For example, the amount of epoxy-modified polyether amide in the UV-curable adhesive may be, but is not limited to, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, or any combination of these values.

[0122] In some embodiments, the epoxy resin includes one or more of alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, and hydrogenated phenolic epoxy resin.

[0123] In some embodiments, the epoxy resin comprises 40 to 80 parts by weight in the UV-curable adhesive. For example, the weight percentage of epoxy resin in the UV-curable adhesive may be, but is not limited to, 40, 45, 50, 55, 60, 65, 70, 75, 80 parts, or any combination thereof. Optionally, the epoxy resin comprises 40 to 70 parts by weight in the UV-curable adhesive.

[0124] In some embodiments, the cationic photoinitiator includes one or more of diazonium salts, diaryliodomonium salts, triarylthionium salts, alkylthionium salts, iron aromatic salts, sulfonyloxy ketones, and triarylsiloxanes. Specifically, the cationic photoinitiator includes one or more of n-6-isopropylbenzylferrocene hexafluorophosphate, 1-hydroxycyclohexylphenyl ketone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, methyl benzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-isopropylthioxanthraphenone, benzoin dimethyl ether, dimethylbenzoyl ketal, and benzophenone.

[0125] In some embodiments, the cationic photoinitiator is present in the photocurable adhesive in the amount of 1 to 5 parts by weight. For example, the amount of cationic photoinitiator in the photocurable adhesive by weight may be, but is not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or any combination of these values.

[0126] In some embodiments, the weight ratio of epoxy resin to epoxy-modified polyether amide is (2~4):1. For example, the weight ratio of epoxy resin to epoxy-modified polyether amide may be, but is not limited to, 2:1, 2.5:1, 3:1, 3.5:1, 4:1 or any combination of these values.

[0127] In some embodiments, the weight ratio of epoxy resin to cationic photoinitiator is (16~40):1. For example, the weight ratio of epoxy resin to cationic photoinitiator may be, but is not limited to, 16:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1, 32:1, 35:1, 38:1, 40:1, or any range of two of these values.

[0128] In some embodiments, the photocurable adhesive further includes one or more of the following: 1 to 20 parts of an accelerator, 1 to 20 parts of an reactive diluent, 1 to 15 parts of a thixotropic modifier, 1 to 5 parts of a coupling agent, and 1 to 5 parts of a functional additive.

[0129] In some embodiments, the accelerator includes an oxetane monomer.

[0130] In some embodiments, the accelerator is present in the UV-cured adhesive in the amount of 1 to 20 parts by weight. For example, the amount of accelerator in the UV-cured adhesive may be, but is not limited to, 1 part, 2 parts, 5 parts, 8 parts, 10.5 parts, 12 parts, 15 parts, 18 parts, 20 parts, or any combination of these values.

[0131] In some embodiments, the reactive diluent includes butyl glycidyl ether, neodecanoic acid glycidyl ether, C 12 ~C 14 One or more of alkyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0132] In some embodiments, the reactive diluent is present in the UV-curable adhesive in the amount of 1 to 20 parts by weight. For example, the amount of reactive diluent in the UV-curable adhesive may be, but is not limited to, 1 part, 2 parts, 5 parts, 8 parts, 10.5 parts, 12 parts, 15 parts, 18 parts, 20 parts, or any combination of these values.

[0133] In some embodiments, the thixotropic modifier includes fumed silica.

[0134] In some embodiments, the thixotropic modifier is present in the UV-curable adhesive in the amount of 1 to 15 parts by weight. For example, the amount of thixotropic modifier in the UV-curable adhesive may be, but is not limited to, 1 part, 2 parts, 4 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, or any combination of these values.

[0135] In some embodiments, the coupling agent comprises a silane coupling agent. Specifically, the coupling agent comprises one or more of γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane.

[0136] In some embodiments, the coupling agent is present in 1 to 5 parts by weight of the UV-curable adhesive. For example, the weight of the coupling agent in the UV-curable adhesive may be, but is not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or any combination of these values.

[0137] In some embodiments, the functional additives include one or more of leveling agents and antioxidants. Specifically, the leveling agents include one or more of leveling agents BYK 3565, BYK 3566, and BYK 3567. The antioxidants include one or more of antioxidants 1010, 1076, and 1098.

[0138] In some embodiments, the functional additive is present in the UV-curable adhesive in the amount of 1 to 5 parts by weight. For example, the amount of functional additive in the UV-curable adhesive may be, but is not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or any combination of these values.

[0139] In some embodiments, the photocurable adhesive comprises, by weight, 40 to 80 parts of epoxy resin, 10 to 40 parts of epoxy-modified polyether amide, 1 to 5 parts of cationic photoinitiator, 1 to 20 parts of accelerator, 1 to 20 parts of reactive diluent, 1 to 15 parts of thixotropic modifier, 1 to 5 parts of coupling agent, and 1 to 5 parts of functional additives.

[0140] In some embodiments, the method for preparing the photocurable adhesive includes: mixing 40 to 80 parts of epoxy resin, 10 to 40 parts of epoxy-modified polyether amide, 1 to 5 parts of cationic photoinitiator, 1 to 20 parts of accelerator, 1 to 20 parts of reactive diluent, 1 to 15 parts of thixotropic modifier, 1 to 5 parts of coupling agent, and 1 to 5 parts of functional additive to prepare the photocurable adhesive.

[0141] It is understood that some embodiments of this application do not have particular limitations on the specific stirring and mixing method, as long as the components are mixed evenly.

[0142] The fourth aspect of this application provides a method for bonding optical elements, comprising the following steps:

[0143] Optical components are bonded using a light-curing adhesive, which is the aforementioned light-curing adhesive.

[0144] In some embodiments, the optical element includes one or more of a lens, a prism, an optical fiber, and an optical sensor.

[0145] In some embodiments, the optical element is made of one or more of glass, polycarbonate (PC), polymethyl methacrylate (PMMA), nylon, cyclic olefin copolymer (COC), cyclic olefin homopolymer (COP), and silicon carbide.

[0146] Specifically, the steps for bonding optical components with a light-curing adhesive include: applying the light-curing adhesive to the optical component and curing it with light.

[0147] This application utilizes photocurable adhesives from some embodiments to bond optical components. The photocurable adhesives contain epoxy-modified polyetheramides capable of cationic photocuring, thereby attaching polyetheramide segments to the epoxy resin during the photocuring process, improving resistance to damp heat. Furthermore, the epoxy-modified polyetheramides contain numerous aliphatic or aromatic ring structures, significantly increasing the light transmittance of the cured product. The flexible polyether segments and polar polyamide segments give the cured product of the photocurable adhesive excellent flexibility, impact resistance, high adhesion, and high resistance to damp heat, making it suitable for bonding various optical lens substrates such as glass, PC, PMMA, nylon, COC, COP, and silicon carbide.

[0148] To make the objectives and advantages of this application clearer, the following detailed description of the photocurable adhesive and its effects, in conjunction with specific embodiments, is provided. It should be understood that the specific embodiments described herein are for illustrative purposes only and should not be construed as limiting the scope of this application. Unless otherwise specified, the following embodiments do not include components other than unavoidable impurities. Unless otherwise specified, the drugs and instruments used in the embodiments are conventional choices in the art. Experimental methods not specifying specific conditions in the embodiments were implemented under conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.

[0149] The main raw materials and reagents used in the following embodiments and comparative examples of this application are as follows. Unless otherwise specified, all other materials and reagents were purchased from commercially available sources.

[0150] Adipic acid: Huafeng Group Co., Ltd., refined adipic acid, industrial grade;

[0151] Sebacic acid: Hengshui Jinghua Chemical Co., Ltd., industrial grade;

[0152] Dodecanoic acid: Shandong Kaisai Biotechnology Co., Ltd., 99.7% purity, industrial grade;

[0153] 4,4'-Diaminodicyclohexylmethane: BASF, industrial grade;

[0154] 3,3'-Dimethyl-4,4'-Diaminodicyclohexylmethane: BASF, industrial grade;

[0155] Polyethylene glycol: Shanghai Aladdin Biochemical Technology Co., Ltd., industrial grade;

[0156] Polypropylene glycol: Shanghai Haohong Biomedical Technology Co., Ltd., industrial grade;

[0157] Polybutanediol: Shanghai Haohong Biomedical Technology Co., Ltd., industrial grade;

[0158] Tetrabutyl zirconate: Shanghai Aladdin Biochemical Technology Co., Ltd., analytical grade;

[0159] Phosphoric acid and sodium phosphite: Beijing Innocare Technology Co., Ltd., analytical grade;

[0160] 4,5-Epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester: Daicel, Japan, industrial grade;

[0161] 3,4-Epoxycyclohexylmethyl-2′,3′-Epoxycyclohexyl ether: Daicel, Japan, industrial grade;

[0162] Hydrogenated bisphenol A epoxy resin: Ningbo Zhilun New Materials Co., Ltd., industrial grade;

[0163] Hydrogenated bisphenol F epoxy resin: Ningbo Zhilun New Materials Co., Ltd., industrial grade;

[0164] Alicyclic epoxy resin 3150: Daicel, Japan, industrial grade;

[0165] The main performance testing methods used in the following embodiments and comparative examples of this application are as follows:

[0166] 1. Shear strength: Using electronic glass as the substrate, after double-sided bonding and curing of an adhesive with an area of ​​10mm×10mm and a thickness of 1mm, the shear strength of the device is tested using a universal tensile testing machine (shear strength = shear stress / bonded area).

[0167] 2. Aging treatment: Using electronic glass as the substrate, a 10mm×10mm thick adhesive is bonded and cured on both sides, and then placed in an aging chamber at 85℃ and 85% relative humidity for 500 hours.

[0168] 3. Curing shrinkage rate: The density of the adhesive before curing (a1) is characterized by weighing with a graduated cylinder, and the density of the adhesive after curing (a2) is characterized by the displacement volume method. The volume shrinkage rate is calculated as (a2-a1) / a2.

[0169] 4. Impact strength: The impact strength of the sample is characterized according to the test standard GB / T 6328-1999;

[0170] 5. Light transmittance: The adhesive is cured into a 100μm thick film, and the light transmittance is characterized using a transmittance tester.

[0171] Synthesis Example 1

[0172] This synthetic example provides an epoxy-modified polyether amide a, the preparation method of which includes the following steps:

[0173] (1) Weigh 1.02 mol of dodecanoic acid and 1 mol of 4,4'-diaminodicyclohexylmethane and add them to the reactor. Maintain an inert environment inside the reactor and set the reaction temperature to 200℃. After reacting for 3 hours, polyamide oligomer a with a weight average molecular weight of 5250 is obtained.

[0174] (2) Weigh 1 mol of the above polyamide oligomer a, 1 mol of polyethylene glycol (weight average molecular weight of 500), 0.0002 mol of phosphoric acid and 0.002 mol of hexamethylenediamine and add them to the reactor. Maintain an inert environment in the reactor and set the reaction temperature to 270℃. After reacting for 7 hours, amino-terminated polyether amide block copolymer a is obtained.

[0175] (3) Weigh 1 mol of the above amino-terminated polyether amide block copolymer a and 2 mol of 4,5-epoxycyclohexane-1,2-diglycidyl ester and add them to the reactor. Set the reaction temperature to 50℃ and react for 5 h to obtain epoxy-modified polyether amide a.

[0176] Synthesis Example 2

[0177] This synthetic example provides an epoxy-modified polyether amide b, the preparation method of which includes the following steps:

[0178] (1) Weigh 1.03 mol sebacic acid and 1 mol 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and add them to the reactor. Maintain an inert environment inside the reactor and set the reaction temperature to 160℃. After reacting for 4 hours, polyamide oligomer b with a weight average molecular weight of 10,000 is obtained.

[0179] (2) Weigh 1 mol of the above polyamide oligomer b, 1 mol of polypropylene glycol (weight average molecular weight of 3000), 0.001 mol of sodium phosphite and 0.01 mol of decanediamine and add them to the reactor. Maintain an inert environment in the reactor and set the reaction temperature to 240℃. After reacting for 8 hours, amino-terminated polyether amide block copolymer b is obtained.

[0180] (3) Weigh 1 mol of the above amino-terminated polyether amide block copolymer b and 2 mol of 3,4-epoxycyclohexylmethyl-2′,3′-epoxycyclohexyl ether and add them to the reactor. Set the reaction temperature to 40°C and react for 6 h to obtain epoxy-modified polyether amide b.

[0181] Synthesis Example 3

[0182] This synthetic example provides an epoxy-modified polyether amide c, the preparation method of which includes the following steps:

[0183] (1) Weigh 1.04 mol of adipic acid and 1 mol of 4,4'-diaminodicyclohexylmethane and add them to the reactor. Maintain an inert environment inside the reactor and set the reaction temperature to 240℃. After reacting for 2 hours, polyamide oligomer C with a weight average molecular weight of 500 is obtained.

[0184] (2) Weigh 1 mol of the above polyamide oligomer c, 1 mol of polybutanediol (weight average molecular weight of 1750), 0.002 mol of tetrabutyl zirconate and 0.02 mol of 4,4'-diaminodicyclohexylmethane and add them to the reactor. Maintain an inert environment in the reactor and set the reaction temperature to 300℃. After reacting for 6 hours, amino-terminated polyether amide block copolymer c is obtained.

[0185] (3) Weigh 1 mol of the above amino-terminated polyether amide block copolymer c and 2 mol of 4,5-epoxycyclohexane-1,2-diglycidyl ester and add them to the reactor. Set the reaction temperature to 60℃ and react for 4 h to obtain epoxy-modified polyether amide c.

[0186] Synthetic Comparative Example 1

[0187] Comparative Example 1 provides an epoxy-modified polyether amide d, which is prepared in a similar manner to that of Synthetic Example 1, except that in step (1), the 4,4'-diaminodicyclohexylmethane in Synthetic Example 1 is replaced with an aliphatic diamine hexamethylenediamine. The other steps are the same as those in Synthetic Example 1 and will not be repeated here.

[0188] Synthetic Comparative Example 2

[0189] Comparative Example 2 provides an epoxy-modified polyether amide e, which is prepared in a similar manner to that of Synthetic Example 1, except that in step (3), an aliphatic epoxy compound such as 1,4-butanediol glycidyl ether is used to replace the 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester in Synthetic Example 1. The other steps are the same as those in Synthetic Example 1 and will not be repeated here.

[0190] Example 1

[0191] This embodiment provides a photocurable adhesive, which is composed of the following components in parts by weight: 60 parts of hydrogenated bisphenol A type epoxy resin, 20 parts of epoxy-modified polyether amide a, 10.5 parts of accelerator OXT-101, 10.5 parts of diluent neodecanoic acid glycidyl ether, 8 parts of thixotropic agent fumed silica, 3 parts of coupling agent γ-mercaptopropyltrimethoxysilane, 3 parts of antioxidant 1010, and 3 parts of blocked hexafluoroantimonate photoinitiator.

[0192] The preparation method of the photocurable adhesive in this embodiment includes the following steps: the above components are stirred evenly using a homogenizer to obtain the photocurable adhesive.

[0193] Example 2

[0194] This embodiment provides a photocurable adhesive, which is composed of the following components in parts by weight: 60 parts of alicyclic epoxy resin, 20 parts of epoxy-modified polyether amide a, 10.5 parts of accelerator OXT-101, 10.5 parts of diluent neodecanoic acid glycidyl ether, 8 parts of thixotropic agent fumed silica, 3 parts of coupling agent γ-mercaptopropyltrimethoxysilane, 3 parts of antioxidant 1010, and 3 parts of blocked hexafluoroantimonate photoinitiator.

[0195] The preparation method of the photocurable adhesive in this embodiment includes the following steps: the above components are stirred evenly using a homogenizer to obtain the photocurable adhesive.

[0196] Example 3

[0197] This embodiment provides a photocurable adhesive and its preparation method, which is composed of the following components in parts by weight: 60 parts of hydrogenated bisphenol F type epoxy resin, 20 parts of epoxy modified polyether amide a, 10.5 parts of accelerator OXT-101, 10.5 parts of diluent neodecanoic acid glycidyl ether, 8 parts of thixotropic agent fumed silica, 3 parts of coupling agent γ-mercaptopropyltrimethoxysilane, 3 parts of antioxidant 1010, and 3 parts of blocked hexafluoroantimonate photoinitiator.

[0198] The preparation method of the photocurable adhesive in this embodiment includes the following steps: the above components are stirred evenly using a homogenizer to obtain the photocurable adhesive.

[0199] Example 4

[0200] This embodiment provides a photocurable adhesive, which is composed of the following components in parts by weight: 40 parts alicyclic epoxy resin, 10 parts epoxy-modified polyether amide b, 1 part accelerator OXT-1, 1 part diluent ethylene glycol diglycidyl ether, 1 part thixotropic agent fumed silica, 1 part coupling agent γ-glycidyl etheroxypropyltrimethoxysilane, 1 part leveling agent BYK3566, and 1 part blocked hexafluoroantimonate photoinitiator.

[0201] The preparation method of the photocurable adhesive in this embodiment includes the following steps: the above components are stirred evenly using a homogenizer to obtain the photocurable adhesive.

[0202] Example 5

[0203] This embodiment provides a photocurable adhesive, which is composed of the following components in parts by weight: 80 parts of hydrogenated bisphenol F type epoxy resin, 40 parts of epoxy modified polyether amide c, 20 parts of accelerator OXT-221, 20 parts of diluent 1,4-butanediol diglycidyl ether, 15 parts of thixotropic agent fumed silica, 5 parts of coupling agent vinyltrimethoxysilane, 5 parts of antioxidant 1098, and 5 parts of blocked hexafluoroantimonate photoinitiator.

[0204] The preparation method of the photocurable adhesive in this embodiment includes the following steps: the above components are stirred evenly using a homogenizer to obtain the photocurable adhesive.

[0205] Comparative Example 1

[0206] Comparative Example 1 provides a light-curing adhesive, which is similar to the light-curing adhesive of Example 1, except that the weight of epoxy-modified polyether amide a is 0. Other components, dosages and preparation steps are the same as in Example 1, and will not be repeated here.

[0207] Comparative Example 2

[0208] Comparative Example 2 provides a photocurable adhesive, which is similar to the photocurable adhesive of Example 1, except that the weight parts of epoxy-modified polyether amide a are 0 parts, the weight parts of hydrogenated bisphenol A type epoxy resin are 0 parts, and the weight parts of alicyclic epoxy resin are 60 parts. The other components, dosages and preparation steps are the same as those in Example 1, and will not be repeated here.

[0209] Comparative Example 3

[0210] Comparative Example 3 provides a photocurable adhesive, similar to the photocurable adhesive of Example 1, except that the weight percentages of epoxy-modified polyether amide a are 0 parts, hydrogenated bisphenol A type epoxy resin is 0 parts, and hydrogenated bisphenol F type epoxy resin is 60 parts. Other components, amounts, and preparation steps are the same as in Example 1 and will not be repeated here.

[0211] Comparative Example 4

[0212] Comparative Example 4 provides a photocurable adhesive, similar to the photocurable adhesive of Example 1, except that the epoxy-modified polyetheramide a in Example 1 is replaced with the amino-terminated polyetheramide block copolymer a prepared in Example 1. Other components, amounts, and preparation steps are the same as in Example 1 and will not be repeated.

[0213] Comparative Example 5

[0214] Comparative Example 5 provides a photocurable adhesive, similar to the photocurable adhesive of Example 1, except that the epoxy-modified polyetheramide a in Example 1 is replaced with the epoxy-modified polyamide d prepared in Comparative Example 1. Other components, amounts, and preparation steps are the same as in Example 1 and will not be repeated.

[0215] Comparative Example 6

[0216] Comparative Example 6 provides a photocurable adhesive, similar to the photocurable adhesive of Example 1, except that the epoxy-modified polyetheramide a in Example 1 is replaced with the epoxy-modified polyamide e prepared in Comparative Example 2. Other components, amounts, and preparation steps are the same as in Example 1 and will not be repeated.

[0217] The photocurable adhesives prepared in Examples 1 to 5 and Comparative Examples 1 to 6 were subjected to the following performance tests, and the results are shown in Table 1:

[0218] Table 1. Performance test results of the photocurable adhesives in each embodiment and comparative example.

[0219]

[0220] By measuring the shear strength, impact strength, curing shrinkage, and shear strength after aging at 85°C and 85%RH for 500 hours, it can be seen that both the comparative example and the embodiment successfully prepared photocurable adhesives. The photocurable adhesive of Comparative Example 1, without the addition of epoxy-modified polyether amide a component, showed a decrease in light transmittance from 99.6% to 92.3% compared to Example 1; a decrease in impact strength from 52 J / m to 10 J / m, with a reduction in toughness of 81%; an increase in volume shrinkage from 0.31% to 1.2%; and a decrease in shear strength from 12.3 MPa to 3.7 MPa after aging at 85°C and 85%RH for 500 hours, with the failure mode changing from cohesive failure to interfacial failure. These results indicate that adding an epoxy-modified polyether amide component to a photocurable adhesive can simultaneously introduce flexible polyether segments and polar cyclic amide segments into the system, improving the adhesive's toughness and light transmittance while helping to maintain its strength under high-temperature and high-humidity aging conditions.

[0221] The UV-curable adhesive in Comparative Example 2 did not contain epoxy-modified polyetheramide component A, and is a conventional alicyclic epoxy UV-curable adhesive. Compared with Example 1, its light transmittance decreased from 99.6% to 93.2%, its impact strength decreased from 52 J / m to 5 J / m, and its shear strength after aging at 85°C and 85%RH for 500 hours decreased from 12.3 MPa to 2.4 MPa. Moreover, its failure mode changed from cohesive failure to interfacial failure, which cannot meet the long-term use requirements in the bonding process of optical lenses.

[0222] The photocurable adhesive in Comparative Example 3 did not contain epoxy-modified polyetheramide component a, and is a conventional hydrogenated bisphenol F type epoxy photocurable adhesive. Compared with Example 1, its light transmittance decreased from 99.6% to 91.7%, and its impact strength decreased from 52 J / m to 12 J / m, which cannot meet the application scenarios with higher optical performance requirements.

[0223] In the photocurable adhesive of Comparative Example 4, the epoxy-modified polyetheramide a in Example 1 was replaced with an amino-terminated polyetheramide block copolymer a. Compared with the photocurable adhesive of Example 1, all properties were significantly reduced. In the photocurable adhesives of Comparative Examples 5 and 6, the epoxy-modified polyamides prepared in Comparative Examples 1 and 2 were used for toughening. Compared with the photocurable adhesive of Example 1, all properties were significantly reduced.

[0224] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0225] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A photocurable adhesive, characterized by, By weight parts, including: epoxy resin 40~80 parts, epoxy modified polyether amide 10~40 parts and cationic photoinitiator 1~5 parts; The raw material of the amino-terminated polyether amide block copolymer comprises a polyether segment and a polyamide segment, the polyamide segment comprises at least one of an alicyclic polyamide segment, a wholly aromatic polyamide segment and a semi-aromatic polyamide segment, and the epoxy compound comprises a multi-function alicyclic epoxy compound.

2. The photocurable adhesive according to claim 1, wherein The polyamide segment comprises an alicyclic polyamide segment, and one of the following conditions is met: (1) the raw material of the polyamide segment comprises an aliphatic dibasic acid and an alicyclic diamine in a molar ratio of (1.02~1.06):1; Optionally, the aliphatic diacid is a C4-C 14 aliphatic diacid; optionally, the aliphatic diacid includes one or more of adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and tetradecanedioic acid; Optionally, the alicyclic diamine comprises one or more of 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-xylylenediamine and norbornene diamine; optionally, the alicyclic diamine comprises one or more of 4,4'-diaminodicyclohexylmethane and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane; (2) the raw material of the polyamide segment comprises an alicyclic dibasic acid and an aliphatic diamine in a molar ratio of (1.02~1.06):1; Optionally, the alicyclic dibasic acid comprises one or more of 1,2-cyclopentane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid and hydrogenated phthalic acid; Optionally, the aliphatic diamine comprises one or more of hexamethylene diamine, nonamethylene diamine, decamethylene diamine and dodecamethylene diamine.

3. The photocurable adhesive according to claim 1, wherein The raw material of the amino-terminated polyether amide block copolymer comprises a polyether segment and a polyamide segment, the polyamide segment comprises at least one of an alicyclic polyamide segment, a wholly aromatic polyamide segment and a semi-aromatic polyamide segment, and the epoxy compound comprises a multi-function alicyclic epoxy compound. Optionally, one or more of the following conditions is met: (1) the polyether polyol comprises one or more of polyethylene glycol, polypropylene glycol and polybutylene glycol; (2) the end-capping agent comprises one or more of an aliphatic diamine and an alicyclic diamine; optionally, the end-capping agent comprises one or more of hexamethylene diamine, nonamethylene diamine, decamethylene diamine, dodecamethylene diamine, 5-amino-1,3,3-trimethylcyclohexylmethylamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, hydrogenated m-xylylenediamine and norbornene diamine; optionally, the end-capping agent comprises one or more of hexamethylene diamine, decamethylene diamine, 4,4'-diaminodicyclohexylmethane and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane; (3) the molar ratio of the polyamide to the polyether polyol is 1:1; (4) the molar amount of the end-capping agent is 0.1% to 1% of the total molar amount of the polyether polyol and the polyamide; (5) the weight average molecular weight of the amino-terminated polyether amide block copolymer is 20,000 or less; optionally, the weight average molecular weight of the amino-terminated polyether amide block copolymer is 10,000 or less; optionally, the weight average molecular weight of the amino-terminated polyether amide block copolymer is 3,000 to 8,000.

4. The photocurable adhesive according to claim 1, wherein the epoxy compound contains an epoxy cyclohexyl group; optionally, the epoxy compound includes one or more of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 3,4-epoxycyclohexylmethyl-2',3'-epoxycyclohexyl ether; and / or, the molar ratio of the amino-terminated polyether amide block copolymer and the epoxy compound is 1:(4 / n), n is the number of epoxy groups in the epoxy compound.

5. The photocurable adhesive according to any one of claims 1 to 4, characterized in that, The photocurable adhesive satisfies one or more of the following conditions: (1) the epoxy resin includes one or more of alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, and hydrogenated phenol-aldehyde epoxy resin; (2) the cationic photoinitiator includes one or more of diazonium salt, diaryliodonium salt, triarylsulfonium salt, alkylsulfonium salt, iron arene salt, sulfonyloxy ketone, and triarylsilyl ether; optionally, the cationic photoinitiator includes one or more of η6-isopropylbenzene ferrocenium hexafluorophosphate, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-(trimethylbenzoyl) diphenyl phosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-phenylbenz-2-dimethylamine-1-(4-morpholinobenzylphenyl) butanone, methyl benzoylformate, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, 2-isopropylthioxanthone, benzoin dimethyl ether, dimethyl benzil ketal, and benzophenone; (3) the weight ratio of the epoxy resin to the epoxy-modified polyether amide is (2 to 4):1; (4) the weight ratio of the epoxy resin to the cationic photoinitiator is (16 to 40):

1.

6. The photocurable adhesive according to any one of claims 1 to 4, wherein The photocurable adhesive further includes one or more of accelerator 1 to 20 parts, active diluent 1 to 20 parts, thixotropy regulator 1 to 15 parts, coupling agent 1 to 5 parts, and functional additive 1 to 5 parts; Optionally, one or more of the following conditions are satisfied: (1) the accelerator includes an oxetane monomer; (2) the reactive diluent comprises one or more of butyl glycidyl ether, neodecanoic acid glycidyl ether, C 12 ~C 14 alkyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and polypropylene glycol diglycidyl ether; (3) the thixotropy regulator includes fumed silica; (4) the coupling agent includes one or more of γ-mercaptopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, γ-ureidopropyl triethoxysilane, γ-glycidyl ether propyl trimethoxysilane, vinyl triethoxysilane, vinyl trimethoxysilane, γ-methacryloyl propyl trimethoxysilane, and γ-mercaptopropyl trimethoxysilane; (5) the functional additive includes one or more of leveling agent and antioxidant.

7. An optical element bonding method characterized by, comprises the following steps: The optical element is bonded with a photocuring adhesive, the photocuring adhesive is the photocuring adhesive according to any one of claims 1-6. Optionally, the optical element comprises one or more of a lens, a prism, an optical fiber, and an optical sensor. Optionally, the material of the optical element comprises one or more of glass, polycarbonate, polymethyl methacrylate, nylon, cyclic olefin copolymer, cyclic olefin homopolymer, and silicon carbide.

8. An epoxy-modified polyetheramide characterized by, The raw materials for preparing the epoxy-modified polyether amide include an amino-terminated polyether amide block copolymer and an epoxy compound, the amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment, the polyamide segment includes at least one of an alicyclic polyamide segment, a wholly aromatic polyamide segment, and a semi-aromatic polyamide segment, and the epoxy compound includes a multi-functional alicyclic epoxy compound.

9. The epoxy-modified polyetheramide of claim 8, wherein, One or more of the following conditions are met: (1) the polyamide segment includes an alicyclic polyamide segment; optionally, the raw materials for preparing the polyamide segment include an aliphatic dibasic acid and an alicyclic dibasic amine in a molar ratio of (1.02-1.06):1, or the raw materials for preparing the polyamide include an alicyclic dibasic acid and an aliphatic dibasic amine in a molar ratio of (1.02-1.06):1; (2) in the amino-terminated polyether amide block copolymer, the polyether segment is connected to the polyamide segment through an ester bond; (3) the weight average molecular weight of the amino-terminated polyether amide block copolymer is less than 20,000; optionally, the weight average molecular weight of the amino-terminated polyether amide block copolymer is less than 10,000; optionally, the weight average molecular weight of the amino-terminated polyether amide block copolymer is 3,000-8,000; (4) the epoxy compound contains an epoxy cyclohexyl group; optionally, the epoxy compound includes one or more of 4,5-epoxycyclohexane-1,2-diglycidyl ester and 3,4-epoxycyclohexylmethyl-2',3'-epoxycyclohexyl ether; (5) the molar ratio of the amino-terminated polyether amide block copolymer to the epoxy compound is 1:(4 / n), and n is the number of epoxy groups in the epoxy compound.

10. A process for the preparation of an epoxy-modified polyetheramide, characterized in that, The method comprises the following steps: reacting an amino-terminated polyether amide block copolymer and an epoxy compound to prepare the epoxy-modified polyether amide block copolymer; wherein the amino-terminated polyether amide block copolymer includes a polyether segment and a polyamide segment, the polyamide segment includes at least one of an alicyclic polyamide segment, a wholly aromatic polyamide segment, and a semi-aromatic polyamide segment, and the epoxy compound includes a multi-functional alicyclic epoxy compound; Optionally, the preparation method meets one or more of the following conditions: (1) in the step of reacting the amino-terminated polyether amide block copolymer and the epoxy compound, the reaction temperature is 40-60°C, and the reaction time is 4-6 hours; (2) the amino-terminated polyether amide block copolymer is prepared by the following steps: mixing a polyamide, a polyether polyol, and an end-capping agent under the action of a catalyst and in a protective atmosphere, and reacting at 240-300°C for 6-8 hours, and the end group of the polyamide is a carboxyl group. (3) the polyamide is prepared by the following steps: reacting a dibasic acid and a dibasic amine under a protective atmosphere at 160°C-240°C for 2h-4h, at least one of the dibasic acid and the dibasic amine being alicyclic or aromatic, the molar ratio being (1.02-1.06):1.

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