阅读说明：本技术 紫外光固化单体和金属胶粘剂 (Ultraviolet light curing monomer and metal adhesive ) 是由 张少林 刘晓明 王珊 于 2020-12-30 设计创作，主要内容包括：本申请涉及紫外光固化技术领域,提供了一种紫外光固化单体和金属胶粘剂。本申请提供的紫外光固化单体的化学结构如式Ⅰ所示,为一类丙烯酸羟烷酯封端的聚氨酯单体,在紫外光照射下具有良好的反应活性,且在紫外光固化后可形成具有三维网络结构的聚合物,具有高粘结力、高韧性和高交联密度,可以使得材料的耐高温性能得到明显提升。将该紫外光固化单体应用于金属胶粘剂时,对金属元件的附着力强,且可明显提升金属胶粘剂的光固化膜的耐高低温性能,从而使得金属元件之间的固定作用明显增强,有利于提高产品良率。(The application relates to the technical field of ultraviolet curing, and provides an ultraviolet curing monomer and a metal adhesive. The chemical structure of the ultraviolet curing monomer is as shown in formula I, the ultraviolet curing monomer is a polyurethane monomer terminated by hydroxyalkyl acrylate, the ultraviolet curing monomer has good reactivity under ultraviolet irradiation, a polymer with a three-dimensional network structure can be formed after ultraviolet curing, the ultraviolet curing monomer has high cohesive force, high toughness and high crosslinking density, and the high temperature resistance of the material can be obviously improved. When the ultraviolet curing monomer is applied to the metal adhesive, the adhesive force to the metal element is strong, and the high and low temperature resistance of the photocuring film of the metal adhesive can be obviously improved, so that the fixing effect between the metal elements is obviously enhanced, and the product yield is favorably improved.)

1. An ultraviolet light curing monomer is characterized in that the chemical structure of the ultraviolet light curing monomer is as shown in formula I:

2. the uv curable monomer of claim 1, wherein R is aryl or arylalkyl.

3. The UV-curable monomer of claim 2, wherein R isR' is hydrogen atom or alkyl with 1-5 carbon atoms.

4. The UV-curable monomer according to claim 3, wherein Ar is phenyl or substituted phenyl.

5. The UV-curable monomer according to claim 4, wherein the substituent in the substituted phenyl group comprises at least one of a halogen atom and an alkyl group having 1 to 5 carbon atoms.

6. The UV-curable monomer according to claim 5, wherein R is any one of the following groups:

7. a metal adhesive comprising a reactive monomer comprising the uv curable monomer of any one of claims 1 to 6.

8. The metal adhesive of claim 7, wherein the metal adhesive comprises the following components in percentage by weight:

93 to 96 percent of active monomer,

3 to 6 percent of photoinitiator,

0.5 to 2 percent of auxiliary agent.

9. The metal adhesive of claim 8, wherein the photoinitiator is a photoinitiator TPO and the adjuvant comprises a silicone defoamer and/or a polyether siloxane leveling agent.

Technical Field

The application belongs to the technical field of ultraviolet curing, and particularly relates to an ultraviolet curing monomer and a metal adhesive.

Background

At present, the metal adhesive used for fixing metal is mainly a UV light curing adhesive, and the curing principle is that an ultraviolet initiator in glue generates active free radicals after absorbing ultraviolet light under the irradiation of ultraviolet rays, so as to initiate monomer polymerization and generate cross-linking polymerization chemical reaction, so that the metal adhesive is converted from a liquid state to a solid state within seconds or tens of seconds, and thus, a plurality of metal elements are fixed. However, the existing UV light curing adhesive has generally unstable high and low temperature resistance, and when the adhesive is used for fixing metal, the adhesive is prone to cracking, falling and other adverse phenomena, resulting in high product reject ratio.

Disclosure of Invention

The application aims to provide an ultraviolet curing monomer and a metal adhesive, and aims to solve the problems that the high and low temperature resistance of the existing UV curing adhesive is generally unstable, and the existing UV curing adhesive is easy to crack and fall off when being used for fixing metal.

In order to solve the technical problem, the technical scheme adopted by the application is as follows:

in a first aspect, the present application provides an ultraviolet curing monomer, which has a chemical structure as shown in formula i:

the ultraviolet curing monomer has a chemical structure shown in formula I, is a polyurethane monomer terminated by hydroxyalkyl acrylate, has good reaction activity under ultraviolet irradiation, can form a polymer with a three-dimensional network structure after ultraviolet curing, has high cohesive force, high toughness and high crosslinking density, and can obviously improve the high temperature resistance of the material. When the ultraviolet curing monomer is applied to the metal adhesive, the adhesive force to the metal element is strong, and the high and low temperature resistance of the photocuring film of the metal adhesive can be obviously improved, so that the fixing effect between the metal elements is obviously enhanced, and the product yield is favorably improved.

In a second aspect, the present application provides a metal adhesive, which includes a reactive monomer, wherein the reactive monomer includes the above ultraviolet light curing monomer.

The metal adhesive provided by the application comprises the ultraviolet curing monomer. Tests show that the metal adhesive has excellent high and low temperature resistance after being used for fixing metal elements, can be used for circulating 600 times under the high and low temperature circulating condition of-40-120 ℃, does not have the undesirable phenomena of cracking, falling and the like, and can play a role in effectively fixing metals.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The embodiment of the application provides an ultraviolet curing monomer, and the chemical structure of the ultraviolet curing monomer is as shown in formula I:

as shown in formula i, the ultraviolet curing monomer provided in the embodiments of the present application is a hydroxyalkyl acrylate-terminated polyurethane monomer, specifically, a hydroxyethyl acrylate-terminated polyurethane, where the polyurethane is formed by polymerizing 4 molecules of isocyanate, and R of each molecule of the isocyanate is connected with 2 molecules of isocyanate (-NCO) and 1 molecule of hydroxyl (-OH). The ultraviolet curing monomer can form a polymer with a three-dimensional network structure after being cured by ultraviolet light, has high cohesive force, high toughness and high crosslinking density, and can obviously improve the high temperature resistance of the material.

In some embodiments, R is aryl or arylalkyl. Specifically, aryl is a class of groups derived from simple aromatic rings, including, but not limited to, phenyl, naphthyl, anthracenyl, biphenyl, and the like. When R is an aryl group, 3 carbon atoms of the aryl group are connected to the chemical structure of the ultraviolet curing monomer by a carbon-carbon single bond (C-C), and in addition, other carbon atoms of the aryl group can be connected with a substituent, wherein the substituent includes but is not limited to a halogen atom, an alkyl group with the carbon atom number of less than 10, and the like. The aryl alkyl group is a group containing both aryl and alkyl groups, the alkyl group is a group containing only C, H atoms, when R is aryl alkyl group, the aryl alkyl group can be connected in the chemical structure of the ultraviolet curing monomer through an aryl part, can also be connected in the chemical structure of the ultraviolet curing monomer through an alkyl part, and can also be connected in the chemical structure of the ultraviolet curing monomer through an aryl part and an alkyl part.

On the basis of the above embodiment, preferably R isR' is hydrogen atom or alkyl with 1-5 carbon atoms. Therefore, the R is connected in the chemical structure of the ultraviolet curing monomer by an aryl part, so that the heat resistance and stability of the product are further improved, and the product has excellent high and low temperature resistance. Specifically, the alkyl group having 1 to 5 carbon atoms includes, but is not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl and the like.

In further embodiments, Ar is phenyl or substituted phenyl. Preferably, the substituent in the substituted phenyl group includes at least one of a halogen atom and an alkyl group having a carbon number of 1 to 5. Specifically, the alkyl group having 1 to 5 carbon atoms includes, but is not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl and the like.

In still further embodiments, R is any one of the following:

in summary, the embodiment of the present application provides an ultraviolet curing monomer having a chemical structure as shown in formula i, which has good reactivity under ultraviolet irradiation, and can form a polymer having a three-dimensional network structure after ultraviolet curing, and has high adhesion, high toughness and high crosslinking density, so that the high temperature resistance of the material can be significantly improved, and the monomer can be used for preparing various photocuring products, including but not limited to adhesives, paints, coatings, inks, and the like, so as to be applied to a plurality of technical fields such as medical devices, security devices, digital electronics, electrician and electrical.

Tests show that when the ultraviolet curing monomer is applied to the adhesive, the adhesive has good adhesive force to various base materials, and compared with other adhesives, the adhesive prepared by the method has stronger adhesive force to metal elements.

The preparation method of the ultraviolet curing monomer can refer to the conventional technology in the field. In some embodiments, the uv curable monomer is synthesized as follows:

s01 synthetic isocyanate prepolymer

Wherein R is

S02 blocking with hydroxyalkyl acrylate

In step S01, a reaction between two groups, i.e., a hydroxyl group (-OH) and an isocyanate group (-NCO), is mainly performed, and specifically, an isocyanate prepolymer is synthesized by an addition reaction between a hydroxyl group and an isocyanate group.

In order to promote the reaction, it is often necessary to add a catalyst during the synthesis of the isocyanate prepolymer, and the catalyst may be selected from conventional urethane catalysts, such as amine catalysts including, but not limited to, N-dimethylcyclohexylamine, bis (2-dimethylaminoethyl) ether, N ' -tetramethylalkylenediamine, triethylamine, N-dimethylbenzylamine, solid amine, N-ethylmorpholine, N-methylmorpholine, N ' -diethylpiperazine, triethanolamine, DMEA, pyridine, N ' -dimethylpyridine, etc., and organic metal catalysts including, but not limited to, dibutyltin dilaurate, organic bismuth, etc. In some embodiments, the catalyst is selected to be dibutyltin dilaurate.

In order to accelerate the reaction, heating is often required during the synthesis of the isocyanate prepolymer. In some embodiments, the reaction temperature is from 50 ℃ to 100 ℃ and the reaction time is from 2 to 10 hours.

In one embodiment, 100g of ultraviolet curing monomer is added into a four-neck flask, dibutyltin dilaurate catalyst is added, the temperature is raised to 60 ℃, the temperature is kept for 30 minutes, the temperature is raised to 80 ℃, and the temperature is kept for 2 hours, so that the isocyanate prepolymer is obtained.

In step S02, hydroxyethyl acrylate is mainly used for the end capping, and the reaction involved is also mainly an addition reaction between two groups, i.e., a hydroxyl group (-OH) and an isocyanate group (-NCO).

In order to promote the reaction, it is often necessary to add a catalyst during the blocking process of the hydroxyalkyl acrylate, and the added catalyst can be referred to step S01, which is not described herein.

To facilitate the reaction, heating is often required during the capping of the hydroxyalkyl acrylate. In some embodiments, the reaction temperature is from 50 ℃ to 100 ℃ and the reaction time is from 2 to 10 hours.

In one embodiment, 1mol of isocyanate prepolymer and 4.5-6mol of hydroxyethyl acrylate are added into a four-neck flask, triethylamine catalyst is added, the temperature is raised to 60 ℃, the temperature is maintained for 30 minutes, the temperature is raised to 80 ℃, and the temperature is maintained for 2-4 hours.

Based on the technical scheme, the embodiment of the application provides the metal adhesive, which comprises the active monomer, wherein the active monomer comprises the ultraviolet curing monomer.

The composition of the metal adhesive can refer to the conventional composition in the field, for example, the metal adhesive consists of an active monomer, a photoinitiator and an auxiliary agent, under the irradiation of ultraviolet light, the photoinitiator in the adhesive generates active free radicals to initiate the ultraviolet curing monomer to perform a cross-linking polymerization reaction, so that the adhesive can be converted from a liquid state to a solid state within seconds or tens of seconds, and a plurality of metal elements are fixed.

The comprehensive performance of the metal adhesive disclosed by the embodiment of the application can be optimized by adjusting and optimizing the using amount of the metal adhesive and the material types of the components.

In some embodiments, the metal adhesive comprises the following components in percentage by weight:

93 to 96 percent of active monomer,

3 to 6 percent of photoinitiator,

0.5 to 2 percent of auxiliary agent.

Specifically, the weight percentage content of the active monomer in the metal adhesive is 93-96%, specifically 93%, 94%, 95% or 96%; the weight percentage of the photoinitiator in the metal adhesive is 3-6 percent, specifically 3 percent, 4 percent, 5 percent or 6 percent; the weight percentage of the auxiliary agent in the metal adhesive is 0.5-2%, specifically 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8% or 2%.

In a further embodiment, the photoinitiator is a photoinitiator TPO (herein named trimethyl benzoyl diphenyl phosphine oxide) and the auxiliaries comprise an organosilicon defoamer and/or a polyether siloxane leveling agent. In one embodiment, the defoamer is selected as silicone defoamer BYK-024 from Bike, Germany and the leveling agent is selected as leveling agent TEGO Glide 432.

Tests show that the metal adhesive has excellent high and low temperature resistance after being used for fixing metal elements, can be used for circulating 600 times under the high and low temperature circulating condition of-40-120 ℃, does not have the undesirable phenomena of cracking, falling and the like, and can play a role in effectively fixing metals.

The practice of the present invention is illustrated by the following examples.

Example 1

The embodiment provides an ultraviolet curing monomer, and the preparation method thereof comprises the following steps:

(1) synthesis of isocyanate prepolymer

100g of monomer is added into a four-neck flask, dibutyltin dilaurate catalyst is added, the temperature is raised to 60 ℃, the temperature is kept for 30 minutes, the temperature is raised to 80 ℃, and the temperature is kept for 2 hours, so that the isocyanate prepolymer is obtained.

The reaction formula involved in this step is as follows:

wherein R is

(2) Hydroxyalkyl acrylate capping

Adding 1mol of isocyanate prepolymer and 4.5-6mol of hydroxyethyl acrylate into a four-mouth flask, adding triethylamine catalyst, heating to 60 ℃, preserving heat for 30 minutes, heating to 80 ℃, and preserving heat for 2-4 hours.

The reaction formula involved in this step is as follows:

example 2

The embodiment provides a metal adhesive which comprises the following components in parts by weight:

96 parts of active monomer, namely 96 parts of active monomer,

3 parts of a photoinitiator,

1 part of an auxiliary agent, namely,

wherein the active monomer is the ultraviolet curing monomer prepared in the embodiment 1, the photoinitiator is a photoinitiator TPO, and the auxiliary agents are an organic silicon defoamer BYK-024 and a flatting agent TEGO Glide 432 in Bike Germany.

Example 3

This example provides a metal adhesive which differs from example 2 in that: the metal adhesive comprises the following components in parts by weight:

95 parts of active monomer, namely, the monomer,

4 parts of a photoinitiator,

and 1 part of an auxiliary agent.

Example 4

This example provides a metal adhesive which differs from example 2 in that: the metal adhesive comprises the following components in parts by weight:

94 parts of an active monomer, namely,

4 parts of a photoinitiator,

and 2 parts of an auxiliary agent.

Example 5

This example provides a metal adhesive which differs from example 2 in that: the metal adhesive comprises the following components in parts by weight:

93 parts of an active monomer, namely a vinyl monomer,

6.5 parts of a photoinitiator,

0.5 part of an auxiliary agent.

The metal adhesive of example 2 was used as a test sample, which was coated on the surface of a metal plate having a threaded hole and the surface of a screw, respectively, the screw was fixed to the metal plate, and then irradiated under ultraviolet light for 50 seconds, and then a high-low temperature test was performed according to standard GB/T2423.22-2002 to test the high-low temperature resistance of a photo-cured film of the metal adhesive.

Tests show that after the photocuring film of the metal adhesive is cycled for 600 times under the high-low temperature cycle condition of-40-120 ℃, the adverse phenomena of cracking, falling and the like can not occur, and the metal part can be effectively fixed.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.