CN114702909B

CN114702909B - UV-thermal dual-curing adhesive and preparation method thereof

Info

Publication number: CN114702909B
Application number: CN202210482901.3A
Authority: CN
Inventors: 张冠军
Original assignee: Bonotec Electronic Materials Co ltd
Current assignee: Bonotec Electronic Materials Co ltd
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2023-09-15
Anticipated expiration: 2042-05-05
Also published as: CN114702909A

Abstract

The invention discloses a UV-thermal dual-curing adhesive and a preparation method thereof. The UV-thermal dual-curing adhesive comprises the following components: alicyclic epoxy resin, an acrylic ester reactive diluent, terephthalic acid, a photoinitiator, a thermal initiator, a sulfhydryl-containing silane coupling agent, an epoxy-containing silane coupling agent, a polymerization inhibitor, an antioxidant and a thixotropic agent. According to the invention, by adding terephthalic acid, carboxyl on a benzene ring reacts with the alicyclic epoxy resin, so that a flexible chain segment can be introduced into an alicyclic epoxy resin main chain, and the alicyclic epoxy resin with better flexibility can be prepared; the alicyclic epoxy resin is combined with the cationic photoinitiator, so that the reaction activity is high, and the curing performance is excellent; in addition, the epoxy-containing silane coupling agent can improve the adhesion of resin to inorganic surfaces, the mechanical properties of resin-based composite materials and the adhesive strength and water resistance of resin coatings; the hydrosulfide-containing silane coupling agent is combined with the gas silicon to improve the performance of the inorganic filler reinforced elastomer.

Description

UV-thermal dual-curing adhesive and preparation method thereof

Technical Field

The invention belongs to the technical field of adhesives, and particularly relates to a UV-thermal dual-curing adhesive and a preparation method thereof.

Background

With the rapid progress of intelligent hardware, intelligent terminal products such as intelligent mobile phones, electric automobiles and PCs are upgraded, and the requirement on adhesives is strict. Ultraviolet light curing is widely applied to the field of the electronic products because of the characteristics of high-efficiency curing, environmental friendliness and the like. However, the traditional ultraviolet light curing adhesive requires good light transmittance of the material, and has low bonding strength and easy falling off after lamination. In recent years, a dual curing mode using ultraviolet light in combination with other curing modes has been increasingly paid attention to in combination with a production mode of downstream customers.

The current mainstream UV dual curing modes comprise UV-moisture, UV-thermal curing and the like, and the UV-moisture contains a polyurethane system, so that the curing time is long, the initial adhesion is not good, and deep curing is difficult to realize. In recent years, the UV-thermal dual-curing adhesive mainly made of the epoxy resin modified material has the characteristics of high curing speed, high hardness, good adhesion and the like, and is widely applied to the adhesion of electronic products.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a UV-heat dual-curing adhesive and a preparation method thereof, so that the UV-heat dual-curing adhesive has the characteristics of short curing time, strong adhesive force, good oxidation resistance, good flexibility and the like.

The aim of the invention can be achieved by the following scheme:

the invention provides a UV-thermal dual-curing adhesive, which comprises the following components in parts by weight:

preferably, the alicyclic epoxy resin comprises at least one of (3, 4-epoxy) cyclohexyl methyl (3, 4-epoxy) cyclohexyl formate (commercial brand mainly CY179/UVR 6110) and bis (3, 4-epoxy cyclohexyl methyl) adipate (commercial brand UVR 6128).

Preferably, the acrylate reactive diluent comprises a mixture of a monofunctional reactive diluent and a difunctional reactive diluent. Not only satisfies the faster curing speed and the increase of the crosslinking density, but also satisfies the good dilutability. Further preferred, the monofunctional reactive diluents include at least one of HEMA, IBOA, CD550 of the beta-CEA, PHEA, sartomer series, CD551, CD552, CD 553; further preferably, the difunctional reactive diluent comprises at least one of HDDA, DPGDA, TPGDA; further preferably, the ratio of the monofunctional reactive diluent to the difunctional reactive diluent is 1-2:1. The ratio is preferably 1:1;1.5:1; 2:1.

Preferably, the photoinitiator comprises at least one of diaryliodonium salt (CD-1012), triphenylsulfonium chloride, phenylmercaptophenyl diphenylsulfonium chloride (PTDPT).

Preferably, the thermal initiator comprises at least one of tertiary amine thermal initiators (BDMA, BDP-10, BDP-30), imidazole thermal initiators (2-MZ, 2-PZ, 2-4 EMZ), boron trifluoride complex thermal initiators (901, 595, 594). The heat curing agent belongs to a latent medium-temperature curing agent, and the curing temperature is 50-100 ℃.

Preferably, the sulfhydryl-containing silane coupling agent is gamma-mercaptopropyl trimethoxy silane (Silquest A-189); the epoxy-containing silane coupling agent is gamma-glycidyl ether oxypropyl trimethoxy silane (KH 560).

Preferably, the polymerization inhibitor comprises at least one of p-hydroxyphenylmethane and hydroquinone.

Preferably, the antioxidant comprises at least one of antioxidant 1010, antioxidant 1076, antioxidant 264 and antioxidant 164.

Preferably, the thixotropic agent comprises at least one of cabot TS-720, yingzhuang Gu Desai R202 and R972.

Preferably, the curing mode of the adhesive is ultraviolet light-heat dual curing.

The invention also provides a preparation method of the UV-thermal dual-curing adhesive, which comprises the following steps:

(a) Dispersing and mixing 30-50 parts of epoxy resin, 8-35 parts of acrylic ester reactive diluent, 5-10 parts of terephthalic acid, 1-3 parts of photoinitiator, 0.5-7.5 parts of sulfhydryl-containing silane coupling agent, 0.5-7.5 parts of epoxy-containing silane coupling agent, 0.1-0.5 part of polymerization inhibitor, 0.1-0.5 part of antioxidant and the like under the dark condition;

(b) Adding 1-10 parts of thixotropic agent, dispersing, mixing and grinding;

(c) And (3) cooling the mixture to room temperature, adding 1-3 parts of thermal initiator, uniformly mixing under vacuum light-shielding condition, defoaming, and preserving under vacuum low temperature to obtain the UV-thermal dual-curing adhesive.

Preferably, in the step a, the dispersion mixing is carried out for 3-5 min under the rotating speed of 1600 r/min. The dispersion mixture was a high-speed disperser THINKY.

Preferably, in the step b, the dispersion and mixing are carried out by using a high-speed dispersing machine THINKY 1600r/min for fully mixing for 3-5 min, and grinding uniformly by using a three-roll machine.

Preferably, in step c, the control temperature is not higher than 40 ℃. Deaeration was performed using a centrifuge. The temperature of vacuum low-temperature preservation is not higher than 4 ℃.

Compared with the prior art, the invention has the advantages that:

(1) According to the invention, by adding terephthalic acid, carboxyl on a benzene ring reacts with the alicyclic epoxy resin, so that a flexible chain segment can be introduced into an alicyclic epoxy resin main chain, and the alicyclic epoxy resin with better flexibility can be prepared;

(2) The epoxy resin containing alicyclic has reasonable price, high reactivity and excellent curing performance when combined with the cationic photoinitiator;

(3) The epoxy-containing silane coupling agent can improve the adhesion of resin to inorganic surfaces, the mechanical properties of resin-based composite materials and the adhesive strength and water resistance of resin coatings; the sulfhydryl-containing silane coupling agent is combined with the gas silicon to improve the performance of the inorganic filler reinforced elastomer, such as tensile stress, tensile strength, tearing strength, heat resistance and wear resistance.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples, which are presented to provide those of ordinary skill in the art with a detailed description of the invention and to provide a further understanding of the invention, are presented in terms of implementation and operation.

Example 1

1. The composition of the dual-cured epoxy adhesive of this example is shown in table 1.

TABLE 1 composition of adhesive in example 1

2. Preparation method

(1) Placing alicyclic epoxy resin, an acrylic ester reactive diluent, terephthalic acid, a photoinitiator, a silane coupling agent, a polymerization inhibitor and an antioxidant into a high-speed centrifuge and fully mixing under a light-shielding condition; adding thixotropic agent, mixing thoroughly, and grinding uniformly by three rollers.

(2) Cooling to room temperature, adding a thermal initiator, stirring and mixing at the temperature of not higher than 40 ℃, and defoaming to obtain the dual-curing adhesive.

Example 2

1. The composition of the dual cure epoxy adhesive of this example is shown in table 2.

TABLE 2 composition of adhesive in example 2

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6128	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝1:1	20
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	2
			Epoxy group-containing silane coupling agent	KH560	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

UVR6110 was replaced with UVR6128, and the remaining preparation conditions were identical to example 1.

Example 3

1. The composition of the dual cure epoxy adhesive of this example is shown in table 3.

TABLE 3 composition of adhesive in example 3

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝2:1	30
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	2
			Epoxy group-containing silane coupling agent	KH560	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

The ratio of acrylate reactive diluent was increased to 30 and HEMA: tpgda=2:1, the remaining preparation conditions were identical to example 1.

Example 4

1. The composition of the dual cure epoxy adhesive of this example is shown in table 4.

TABLE 4 composition of the adhesive in example 4

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	CD553:TPGDA＝1:1	20
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	2
			Epoxy group-containing silane coupling agent	KH560	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

HEMA: tpgda=1:1 was changed to CD553: tpgda=1:1, and the remaining preparation conditions were identical to example 1.

Example 5

1. The composition of the dual cure epoxy adhesive of this example is shown in table 5.

TABLE 5 composition of adhesive in example 5

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	45
Reactive diluents for acrylic esters	CD553:TPGDA＝1:1	30
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	2
			Epoxy group-containing silane coupling agent	KH560	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

The remaining preparation conditions were identical to example 1, except that the UVR6110 weight component was changed to 45, and the cd 553:tpgda=1:1 weight component was changed to 30.

Comparative example 1

1. The composition of the dual-cured epoxy adhesive of this comparative example is shown in Table 6, comparative example 1, with no terephthalic acid added.

TABLE 6 composition of adhesive in comparative example 1

2. Preparation method

Terephthalic acid was not added, and the other preparation conditions were the same as in example 1.

Comparative example 2

1. The composition of the dual-cured epoxy adhesive of this comparative example is shown in Table 7, comparative example 1, in which terephthalic acid was replaced with other organic acids such as salicylic acid.

TABLE 7 composition of adhesive in comparative example 2

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝1:1	20
			Salicylic acid	Salicylic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	2
			Epoxy group-containing silane coupling agent	KH560	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

Terephthalic acid was replaced with salicylic acid, and the remaining preparation conditions were the same as in example 1.

Comparative example 3

1. The composition of the dual-cured epoxy adhesive of this comparative example is shown in Table 8, comparative example 1, without the addition of a mercapto group-containing silane coupling agent.

TABLE 8 composition of adhesive in comparative example 3

2. Preparation method

The other preparation conditions were the same as in example 1 without adding a mercapto group-containing silane coupling agent.

Comparative example 4

1. The composition of the dual-cured epoxy adhesive of this comparative example is shown in Table 9, comparative example 1, in which no epoxy group-containing silane coupling agent was added.

TABLE 9 composition of the adhesive in comparative example 4

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝1:1	20
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Mercapto-containing silane coupling agent	Silquest A-189	4
			Polymerization inhibitor	Hydroquinone (HQ)	0.2
Antioxidant	1010	0.2
			Thixotropic agent	TS 720	5

2. Preparation method

The other preparation conditions were the same as in example 1 without adding the epoxy group-containing silane coupling agent.

Comparative example 5

1. The composition of the dual-cured epoxy adhesive of this comparative example is shown in Table 10, and comparative example 1, in which any silane coupling agent was not added, increases the composition of the reactive diluent of acrylic acid ester to 24.

Table 10 composition of the adhesive in comparative example 5

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝1:1	24
			Terephthalic acid	Terephthalic acid	8
Photoinitiator	PTDPT	2
			Thermal initiator	2-MZ	2
Polymerization inhibitor	Hydroquinone (HQ)	0.2
			Antioxidant	1010	0.2
Thixotropic agent	TS 720	5

2. Preparation method

Any silane coupling agent was not added, and the other preparation conditions were the same as in example 1.

Comparative example 6

1. The composition of the dual-cured epoxy adhesive of this example is shown in Table 11, and comparative example 1, in which no terephthalic acid was added and no silane coupling agent was added, increases the acrylate reactive diluent component to 32.

TABLE 11 composition of adhesive in comparative example 6

Component (A)	Name of the name	Weight component
			Cycloaliphatic epoxy resins	UVR6110	35
Reactive diluents for acrylic esters	HEMA:TPGDA＝1:1	32
			Photoinitiator	PTDPT	2
Thermal initiator	2-MZ	2
			Polymerization inhibitor	Hydroquinone (HQ)	0.2
Antioxidant	1010	0.2
			Thixotropic agent	TS 720	5

2. Preparation method

Terephthalic acid and any silane coupling agent were not added, and the other preparation conditions were the same as in example 1.

Results testing:

(1) Tensile Strength experiment

The UV-thermosetting adhesives prepared in the examples 1-5 and the comparative examples 1-5 are respectively coated in dumbbell-shaped molds prepared according to GB/T1040, cured for 1min in a state of 574w by a UV 365nm curing machine, then cured for 30min at 100 ℃ in an oven, cooled to room temperature, and the obtained sample is tested for tensile strength according to GB/T1040 by a CMT4304 universal tensile machine;

(2) Thrust experiment

The UV-thermosetting adhesives prepared in examples 1-5 and comparative examples 1-5 were coated on 3X 3mm small PC sheets, carefully re-attached to the PC sheets, cured for 1min with a UV 365nm curing machine 574w (first attached and then irradiated), then cured for 30min at 100℃in an oven, cooled to room temperature, and subjected to a thrust test in a DAGA 4000 thrust machine according to GB/T2792;

the results are shown in Table 12:

TABLE 12 adhesive performance test results as described above

As can be seen from Table 12, according to the embodiment of the invention, the performance of the UV-thermosetting adhesive such as temperature resistance, adhesive force, tensile strength, flexibility and the like can be improved by adding terephthalic acid, a mercapto-containing silane coupling agent and an epoxy-containing silane coupling agent to compound and modify the alicyclic epoxy resin. Wherein, terephthalic acid added in the embodiment of the invention is combined with alicyclic epoxy resin, so that the flexibility is improved, meanwhile, the adhesive force is not negatively influenced, and after salicylic acid is used for replacing terephthalic acid, the adhesive force is not greatly changed, but the flexibility is poor; the silane coupling agent containing sulfhydryl is added to improve the physical and mechanical properties of the glue; the addition of the epoxy-containing silane coupling agent plays a role in improving the adhesive force, and the adhesive force is not affected under the high-temperature condition.

It will be apparent to those skilled in the art from this disclosure that various other changes and modifications can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The UV-thermal dual-curing adhesive is characterized by comprising the following components in parts by weight:

30-50 parts of alicyclic epoxy resin;

8-35 parts of acrylic ester reactive diluent;

5-10 parts of terephthalic acid;

1-3 parts of photoinitiator;

1-3 parts of a thermal initiator;

0.5 to 7.5 portions of sulfydryl-containing silane coupling agent;

0.5 to 7.5 portions of epoxy group-containing silane coupling agent;

0.1 to 0.5 part of polymerization inhibitor;

0.1 to 0.5 part of antioxidant;

1-10 parts of thixotropic agent;

the sulfhydryl-containing silane coupling agent is gamma-sulfhydryl propyl trimethoxy silane; the epoxy group-containing silane coupling agent is gamma-glycidyl ether oxypropyl trimethoxy silane; the thixotropic agent comprises at least one of cabot TS-720, yingchuang Gu Desai R202 and R972;

the photoinitiator comprises at least one of diaryl iodonium salt, triphenyl sulfonium chloride and phenylmercapto phenyl diphenyl sulfonium chloride; the thermal initiator comprises at least one of tertiary amine thermal initiator, imidazole thermal initiator and boron trifluoride complex thermal initiator.

2. The UV-thermal dual-cure adhesive of claim 1, wherein the cycloaliphatic epoxy resin comprises at least one of (3, 4-epoxy) cyclohexylmethyl (3, 4-epoxy) cyclohexyl carboxylate and bis (3, 4-epoxycyclohexylmethyl) adipate.

3. The UV-thermal dual cure adhesive of claim 1, wherein the acrylate reactive diluent comprises a mixture of mono-functional reactive diluents and di-functional reactive diluents.

4. The UV-thermal dual-cure adhesive of claim 1, wherein the polymerization inhibitor comprises at least one of p-hydroxyphenylmethane and hydroquinone.

5. The UV-thermal dual-cure adhesive of claim 1, wherein the antioxidant comprises at least one of antioxidant 1010, antioxidant 1076, antioxidant 264, and antioxidant 164.

6. A method of preparing the UV-thermal dual-cure adhesive according to claim 1, comprising the steps of:

(a) 30 to 50 parts of alicyclic epoxy resin, 8 to 35 parts of acrylic ester reactive diluent, 5 to 10 parts of terephthalic acid, 1 to 3 parts of photoinitiator, 0.5 to 7.5 parts of sulfydryl-containing silane coupling agent, 0.5 to 7.5 parts of epoxy-containing silane coupling agent, 0.1 to 0.5 part of polymerization inhibitor, 0.1 to 0.5 part of antioxidant and light-shielding condition are dispersed and mixed;

(b) Adding 1-10 parts of thixotropic agent, dispersing, mixing and grinding;