Preparation method and application of epoxy glue with high impact resistance and high curing depth

Abstract

The invention discloses a preparation method and application of an epoxy adhesive, and the preparation method comprises the following steps: sequentially weighing epoxy resin, polyol, toughened resin and filler, and uniformly stirring and mixing to obtain a mixture A; adding an initiator and gaseous silicon into the mixture A, and uniformly stirring and mixing to obtain a mixture B; adding an oxidizing agent into the mixture B, vacuumizing, defoaming, uniformly mixing, and discharging to obtain the adhesive. The high-impact-resistance and high-curing-depth epoxy glue disclosed by the invention has the advantages of excellent curing performance, high curing speed and high production efficiency, and the cured packaging glue has high impact resistance and high curing depth performance; the modulus of the epoxy glue with high impact resistance and high curing depth is less than 3.5 GPa; according to the high-impact-resistance and high-curing-depth epoxy glue disclosed by the invention, various base materials are excellently bonded, and the glass-PI bonding force is greater than 10MPa; the epoxy adhesive disclosed by the invention has good application performance and is easy to operate and apply.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy adhesives, and in particular relates to a preparation method and application of a high-impact-resistant and high-curing-depth epoxy adhesive. Background Art

[0002] Epoxy adhesives, referred to as epoxy glue, are a type of bonding material, mainly composed of two parts: epoxy resin and curing agent. They have the characteristics of good adhesion, high adhesive strength, low shrinkage, dimensional stability, excellent electrical properties, resistance to chemical media, easy configuration, simple process, and no pollution to the environment. They are widely used in aviation, construction, machinery and other fields.

[0003] The application of high impact resistance and high curing depth epoxy adhesive in intelligent manufacturing, new energy vehicles, aerospace and other fields will be further expanded. In the future, environmentally friendly and high-performance epoxy adhesives will become the mainstream of the market, meeting stricter environmental protection requirements and higher industrial standards.

[0004] The protective structure of the flexible circuit board needs to be fixed with a specific glue to ensure its complete structure, and the adhesive needs to be able to bend with the FPC, which requires the material to have a relatively high impact resistance; and since the FPC is used for electronic component structures, this type of structure is sensitive to light or heat, so when the adhesive is curing, it is necessary to ensure that the performance of the electronic components is not affected by the curing method; and in the process of protecting the FPC with the adhesive, bubbles as defects will cause serious poor dielectric properties, so it is necessary to control the bubble content and size of the system.

[0005] The packaging of flexible circuit boards with low-temperature epoxy is a typical application form, but since epoxy glue needs to be heated for curing and the curing time is relatively long, a more effective curing method is needed. UV curing has been used in light-transmitting application scenarios due to its advantages such as low energy and high efficiency.

[0006] For the curing of UV epoxy adhesives, typical initiators absorb short-wavelength ultraviolet rays, and the curing depth is shallow. However, for the application of circuit board protection, it is hoped that the curing depth of the adhesive can be increased as much as possible. In summary, the development of an epoxy adhesive with high impact resistance and high curing depth has become an urgent problem to be solved. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for preparing a high-impact and high-curing-depth epoxy adhesive is provided, comprising:

[0011] Weigh epoxy resin, polyol, toughening resin and filler in sequence, stir and mix well to obtain mixture A;

[0012] Adding the initiator and the gas silicon into the mixture A and stirring to obtain a mixture B;

[0013] The oxidant is added to the mixture B, vacuumed and degassed, mixed evenly, and discharged to obtain an adhesive;

[0014] Among them, the epoxy resin is an alicyclic epoxy resin, including one or more of epoxy 2021P, 8010, and 2081; the polyol is a polyether or polyester polyol, including one or more of H-1830, Kflex1-88, and GP-700; the toughening resin is a core-shell structure toughening resin, including one or more of MX533, ​​154, TMS-2670J, and TMS-2672; the filler includes one or more of silica and glass powder; the initiator includes one or more of ferrocene initiator or cationic initiator; the oxidant is an organic peroxide, including isopropylbenzene hydroperoxide.

[0015] As a preferred embodiment of the preparation method of the present invention, the epoxy resin comprises 20 to 50 parts, the polyol comprises 10 to 30 parts, the toughening resin comprises 5 to 20 parts, the filler comprises 5 to 20 parts, the initiator comprises 0.5 to 2 parts, the silica gel comprises 0.5 to 2 parts and the oxidant comprises 0.5 to 2 parts.

[0016] As a preferred embodiment of the preparation method of the present invention, the epoxy resin comprises 25 to 45 parts, the polyol comprises 15 to 25 parts, the toughening resin comprises 5 to 15 parts, the filler comprises 10 to 20 parts, the initiator comprises 1 to 2 parts, the silica gel comprises 1 to 2 parts and the oxidant comprises 1 to 2 parts.

[0017] As a preferred embodiment of the preparation method of the present invention, the epoxy resin comprises a difunctional or polyfunctional epoxy resin, and the structural glycidyl ether is directly connected to the ester ring skeleton.

[0018] As a preferred embodiment of the preparation method of the present invention, the initiator is composed of ferrocene and iodonium salt.

[0019] As a preferred embodiment of the preparation method of the present invention, the stirring speed is 1000-2000 rpm, and the stirring time is 10-30 min.

[0020] Another object of the present invention is to overcome the deficiencies in the prior art and provide a high impact resistant and high curing depth epoxy adhesive.

[0021] As a preferred embodiment of the high impact resistant and high curing depth epoxy adhesive of the present invention, the high impact resistant and high curing depth epoxy adhesive is cured in the visible light region, the curing wavelength is greater than 430nm, and the curing depth is greater than 10mm.

[0022] As a preferred solution of the high impact resistant and high curing depth epoxy adhesive of the present invention, the modulus of the high impact resistant and high curing depth epoxy adhesive is less than 3.5 GPa.

[0023] Another object of the present invention is to overcome the deficiencies in the prior art and provide a high impact resistant and high curing depth epoxy adhesive for use in the preparation of flexible circuit boards.

[0024] Beneficial effects of the present invention:

[0025] 1. The high impact resistance and high curing depth epoxy adhesive of the present invention has excellent curing performance, fast curing speed, high production efficiency, and the cured encapsulation adhesive has high impact resistance and high curing depth performance;

[0026] 2. The modulus of the high impact resistance and high curing depth epoxy adhesive of the present invention is less than 3.5 GPa.;

[0027] 3. The high impact resistance and high curing depth epoxy adhesive of the present invention has excellent bonding to various substrates, and the glass-PI bonding strength is greater than 10MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0029] Figure 1 This is a measurement diagram of the curing depth of the epoxy adhesive in Example 1 of the present invention.

[0030] Figure 2 This is a measurement diagram of the curing depth of the epoxy adhesive in Example 2 of the present invention.

[0031] Figure 3 This is a measurement diagram of the curing depth of the epoxy adhesive in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] The raw materials and reagents used in the present invention are shown in Table 1:

[0036] Table 1

[0037]

[0038] The performance test method of the high impact resistance and high curing depth epoxy adhesive prepared in each embodiment and comparative example of the present invention is as follows:

[0039] Shock test:

[0040] The sample was dotted on a 25*25mm glass into a circular ring shape with a width of 2mm and a diameter of 15mm by a dispensing machine, and covered on the glass with a 25*12.5 aluminum plate, and the thickness of the glue layer was controlled by a 100um spacer. The sample was irradiated vertically from top to bottom for 300s with visible light of 450nm wavelength and power of 350mW / cm2. After being placed at room temperature for 24 hours, an impact test was performed using a DuPont impact tester. After obtaining the height, the impact potential energy obtained per unit glue area was calculated and calculated as the impact strength.

[0041] Curing ability and curing depth test: inject glue into a black PE tube with a diameter of 5mm and a depth of 20mm, and irradiate it vertically from top to bottom for 300s with visible light of 450nm wavelength and power of 350mW / cm2. After irradiation, cut the PE tube with a utility knife, take out the sample, soak it in ethanol for 1 minute, and wipe off the gel part of the glue with a dust-free cloth. Measure the length of the remaining part to obtain the curing depth data.

[0042] Adhesion test: refer to GB / T 7124-86, the aluminum substrates used for testing are scrubbed with ethanol to remove oil, the glue sample is applied to the surface to be bonded, and then the thickness of the glue layer is controlled with a 125μm iron wire; after the treatment, the surface of the aluminum substrate is covered with glass, and then irradiated vertically from top to bottom with visible light of 450nm wavelength and power of 350mW / cm2 for 300s. Take out the sample, place it at room temperature for 24 hours, and then test it on a tensile testing machine.

[0043] Aging test: Refer to the adhesion test method. After preparing the shear sample, place the sample in an environment of 65℃ / 95% humidity. After 7 days, take out the sample, place it at room temperature for 1 hour, and perform a tensile test on a tensile testing machine. The data obtained is compared with the data before aging to determine the degree of adhesion retention and obtain data.

[0044] Example 1

[0045] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0046] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0047] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0048] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0049] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as Adhesive 1.

[0050] 2. Performance Testing

[0051] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 13.6mJ / mm 2 , the bonding strength is 13.8MPa, it can be cured at a wavelength of 450nm, and the curing depth is Figure 1 As shown, for 10mm, the aging adhesion retention value after 60℃ / 90% / 7days is 95%.

[0052] Example 2

[0053] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0054] (1) Weigh 50 parts of epoxy 2021P, 10 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0055] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0056] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0057] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuum-treated for degassing, and stirred three times to obtain an adhesive, which was recorded as Adhesive 2.

[0058] 2. Performance Testing

[0059] Adhesive 2 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 2 was 14.8mJ / mm 2 , the bonding strength is 12.3MPa, it can be cured at a wavelength of 450nm, and the curing depth is Figure 2 As shown, for 10 mm, the aging adhesion retention value after 60°C / 90% / 7 days is 110%.

[0060] Example 3

[0061] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0062] (1) Weigh 20 parts of epoxy 2021P, 40 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0063] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0064] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0065] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as Adhesive 3.

[0066] 2. Performance Testing

[0067] Adhesive 3 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 3 was 15.3mJ / mm 2 The bonding strength is 13.2MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 89%.

[0068] Example 4

[0069] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0070] (1) Weigh 20 parts of epoxy 2021P, 40 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0071] (2) After the mixture cools to room temperature, 0.5 parts of ferrocene initiator GR-261, 1.5 parts of cationic initiator GR-IS051, and 2 parts of gas silica TS720 are added in sequence, and mechanically stirred at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0072] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0073] (4) The mixture was stirred at a speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated 3 times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as Adhesive 4.

[0074] 2. Performance Testing

[0075] Adhesive 4 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 4 was 12.8mJ / mm 2 The bonding strength is 13.2MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 95%.

[0076] Comparative Example 1

[0077] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0078] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0079] (2) After the mixture cools to room temperature, 2 parts of ferrocene initiator GR-261 and 2 parts of gas silica TS720 are added in sequence, and the mixture is mechanically stirred at a speed of 1000 rpm for 25 minutes and mixed uniformly;

[0080] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0081] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 1.

[0082] 2. Performance Testing

[0083] Comparative adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of comparative adhesive 1 was 2.1mJ / mm 2 The bonding strength is 3.3MPa. It can be cured at a wavelength of 450nm. The curing speed is slow and it is gel-like. The curing depth is as Figure 3 As shown, it is 5mm, and the aging adhesion retention value after 60℃ / 90% / 7days is 30%.

[0084] Comparative Example 2

[0085] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0086] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0087] (2) After the mixture cools to room temperature, add 2 parts of cationic initiator GR-IS051 and 2 parts of gas silicon TS720 in sequence, and stir mechanically at a speed of 1000 rpm for 25 minutes until the mixture is uniformly mixed;

[0088] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0089] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times to mix evenly to obtain an adhesive, which was recorded as comparative adhesive 2.

[0090] 2. Performance Testing

[0091] Comparative Adhesive 2 was subjected to various performance tests including impact resistance test, curing ability and curing depth test, and adhesion test. Comparative Adhesive 2 could not be cured at a wavelength of 450nm.

[0092] Comparative Example 3

[0093] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0094] (1) Weigh 60 parts of epoxy 2021P, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer until they are uniform;

[0095] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0096] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0097] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated 3 times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 3.

[0098] 2. Performance Testing

[0099] Comparative adhesive 3 was tested for impact resistance, curing ability and curing depth, and bonding strength. The impact strength of comparative adhesive 3 was 6.7mJ / mm 2 The bonding strength is 18MPa. It can be cured at a wavelength of 450nm. The curing speed is very slow. The curing depth is 10mm. The aging bonding strength retention value after 60℃ / 90% / 7day is 110%.

[0100] Comparative Example 4

[0101] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0102] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of talcum powder in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0103] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0104] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0105] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 4.

[0106] 2. Performance Testing

[0107] Comparative adhesive 4 was tested for impact resistance, curing ability and curing depth, and bonding strength. The impact strength of comparative adhesive 4 was 10.9 mJ / mm 2 The bonding strength is 10MPa, it can be cured at a wavelength of 450nm, the curing depth is 3mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 105%.

[0108] Comparative Example 5

[0109] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0110] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, and 16 parts of MX533 toughening resin in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer until they are uniformly mixed;

[0111] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0112] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0113] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 5.

[0114] 2. Performance Testing

[0115] Comparative adhesive 5 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of comparative adhesive 5 was 11.9mJ / mm 2 The bonding strength is 10MPa, it can be cured at a wavelength of 450nm, the curing depth is 5mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 60%.

[0116] Comparative Example 6

[0117] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0118] (1) Weigh 30 parts of epoxy 2021P, 30 parts of polyol Kflex1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0119] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0120] (3) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 6.

[0121] 2. Performance Testing

[0122] Comparative adhesive 6 was tested for impact resistance, curing ability and curing depth, and bonding strength. The impact strength of comparative adhesive 6 was 13.7 mJ / mm 2 The bonding strength is 10MPa. It can be cured at a wavelength of 450nm. The curing speed is very slow. The curing depth is 3mm. The aging bonding strength retention value after 60℃ / 90% / 7day is 95%.

[0123] The performance test results of the high impact resistant and high curing depth epoxy adhesives prepared in various embodiments and comparative examples are shown in Table 2.

[0124] Table 2

[0125]

[0126]

[0127] The results are shown in Table 2. Through the experiments of Comparative Example 1, Comparative Example 2, Comparative Example 6 and Example 1, it was found that cationic initiators, free radical initiators and peroxides need to work together to form a high curing depth. The initiation of a single initiator leads to a shallower curing depth, <5mm; by comparing Comparative Example 3 with Example 1, it can be seen that the introduction of polyols can greatly increase the curing speed. Moreover, the introduction of polyols can enhance the impact resistance of the adhesive. By comparing Comparative Example 4 with Example 1, it can be seen that transparent fillers can effectively increase the curing depth, while light-shielding fillers will greatly affect the curing depth. By comparing Comparative Example 5 with Example 1, it can be seen that the addition of fillers can effectively improve the aging performance of the adhesive bonding force.

[0128] Example 5

[0129] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0130] (1) Weigh 50 parts of Daicel 8010, 10 parts of polyol Kflex 1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0131] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0132] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0133] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 5.

[0134] 2. Performance Testing

[0135] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 12.9mJ / mm 2 The bonding strength is 18.3MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 110%.

[0136] Example 6

[0137] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0138] (1) Weigh 40 parts of epoxy 2021P, 20 parts of H-1830, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0139] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0140] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0141] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 6.

[0142] 2. Performance Testing

[0143] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 16.7mJ / mm 2 The bonding strength is 16.8MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 98%.

[0144] Example 7

[0145] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0146] (1) Weigh 40 parts of epoxy 2021P, 20 parts of GMP-700, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0147] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0148] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0149] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuum-treated for degassing, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 7.

[0150] 2. Performance Testing

[0151] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 13.2mJ / mm 2 The bonding strength is 13.1MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 93%.

[0152] Example 8

[0153] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0154] (1) Weigh 24 parts of epoxy 2021P, 24 parts of Daicel 8010, 10 parts of polyol Kflex1-88, 10 parts of GMP-700, 8 parts of TMS-2672 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir at 1000 rpm for 30 min with a mechanical stirrer and mix them uniformly;

[0155] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0156] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0157] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 8.

[0158] 2. Performance Testing

[0159] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 15.2mJ / mm 2 The bonding strength is 14.2MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 102%.

[0160] Example 9

[0161] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0162] (1) Weigh 45 parts of epoxy 2021P, 25 parts of GMP-700, 16 parts of toughening resin MX533, ​​and 10 parts of PLV6 in order by mass, stir them at 1000 rpm for 30 minutes with a mechanical stirrer until they are uniform;

[0163] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0164] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0165] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed to degas, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 9.

[0166] 2. Performance Testing

[0167] Adhesive 1 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of adhesive 1 was 14.2mJ / mm 2 The bonding strength is 13.1MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 97%.

[0168] Example 10

[0169] 1. This embodiment provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0170] (1) Weigh 50 parts of Daicel 2081, 10 parts of polyol Kflex 1-88, 16 parts of MX533 toughening resin, and 20 parts of silica MC9809 filler in order by mass, stir them at a speed of 1000 rpm for 30 minutes with a mechanical stirrer and mix them uniformly;

[0171] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0172] (3) Add 1 part CHP and mix uniformly after mechanical stirring for 10 min;

[0173] (4) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuum-treated for degassing, and stirred three times until the mixture was evenly mixed to obtain an adhesive, which was recorded as Adhesive 10.

[0174] 2. Performance Testing

[0175] The adhesive 10 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of the adhesive 10 was 13.2 mJ / mm 2 The bonding strength is 18.5MPa, it can be cured at a wavelength of 450nm, the curing depth is 10mm, and the aging bonding strength retention value after 60℃ / 90% / 7days is 105%.

[0176] Comparative Example 7

[0177] 1. This comparative example provides a method for preparing a high impact resistant and high curing depth epoxy adhesive.

[0178] (1) Weigh 76 parts of epoxy 2021P and 20 parts of silica MC 9809 in order by mass, stir them at 1000 rpm for 30 min with a mechanical stirrer until they are uniformly mixed;

[0179] (2) After the mixture cools to room temperature, add 1 part of ferrocene initiator GR-261, 1 part of cationic initiator GR-IS051, and 2 parts of gas silica TS720 in sequence, and mechanically stir at a speed of 1000 rpm for 25 minutes to mix uniformly;

[0180] (3) The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, vacuumed and degassed, and the stirring was repeated three times. The mixture was mixed evenly and discharged to obtain an adhesive, which was recorded as comparative adhesive 7.

[0181] 2. Performance Testing

[0182] Comparative adhesive 7 was subjected to impact resistance test, curing ability and curing depth test, and bonding strength test. The impact strength of comparative adhesive 7 was 5.4mJ / mm 2 The bonding strength is 17MPa. It can be cured at a wavelength of 450nm. The curing speed is relatively slow. The curing depth is 4mm. The aging bonding strength retention value after 60℃ / 90% / 7days is 98%.

[0183] The performance test results of the high impact resistant and high curing depth epoxy adhesives prepared in various embodiments and comparative examples are shown in Table 3.

[0184] Table 3

[0185]

[0186]

[0187] The results are shown in Table 3. Epoxy 2081 and 8010 in Examples 5 and 10 are alicyclic epoxies; H-1830 in Example 6 is a hydrogenated castor oil type polyol, and GMP-700 in Example 7 is a polyether type polyol. Under the same substitution, the requirements of adhesion, curing depth, impact resistance and other performances can be met. Different toughening agents are used in Examples 8 and 9. Compared with Comparative Example 7, it can be experimentally proved that the core-shell structure can effectively improve the toughness of the material.

[0188] In summary, the epoxy adhesive prepared by the synergistic effect of the cationic initiator and the peroxide in the present invention achieves the performance of curing under long wavelength, and the curing depth can reach more than 10mm, and a high-toughness UV-type epoxy adhesive is achieved by using polyols and toughening resins.

[0189] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a high impact resistant and high curing depth epoxy adhesive, characterized in that: include, Weigh epoxy resin, polyol, toughening resin and filler in sequence, stir and mix well to obtain mixture A; Adding the initiator and the gas silicon into the mixture A and stirring to obtain a mixture B; The oxidant is added to the mixture B, vacuumed and degassed, mixed evenly, and discharged to obtain an adhesive; Among them, the epoxy resin is an alicyclic epoxy resin, including one or more of epoxy 2021P, 8010, and 2081; the polyol is a polyether or polyester polyol, including one or more of H-1830, Kflex 1-88, and GP-700; the toughening resin is a core-shell structure toughening resin, including one or more of MX533, ​​154, TMS-2670J, and TMS-2672; the filler includes one or more of silica and glass powder; the initiator includes one or more of ferrocene initiator or cationic initiator; the oxidant is an organic peroxide, including isopropylbenzene hydroperoxide.

2. The preparation method according to claim 1, characterized in that: Calculated by weight of raw materials, the epoxy resin is 20-50 parts, the polyol is 10-30 parts, the toughening resin is 5-20 parts, the filler is 5-20 parts, the initiator is 0.5-2 parts, the gas silicon is 0.5-2 parts and the oxidant is 0.5-2 parts.

3. The preparation method according to claim 1, characterized in that: Calculated by mass of raw materials, the epoxy resin is 25-45 parts, the polyol is 15-25 parts, the toughening resin is 5-15 parts, the filler is 10-20 parts, the initiator is 1-2 parts, the gas silicon is 1-2 parts and the oxidant is 1-2 parts.

4. The preparation method according to claim 1, characterized in that: The epoxy resin includes a difunctional or polyfunctional epoxy resin, and the structural glycidyl ether is directly connected to the ester ring skeleton.

5. The preparation method according to claim 1, characterized in that: The initiator consists of ferrocene and iodonium salt.

6. The preparation method according to claim 1, characterized in that: The stirring speed is 1000-2000 rpm, and the stirring time is 10-30 min.

7. The high impact resistant and high curing depth epoxy adhesive prepared by the preparation method according to claims 1 to 6.

8. The high impact resistant and high curing depth epoxy adhesive as claimed in claim 7, characterized in that: The high impact resistance and high curing depth epoxy adhesive is cured in the visible light region, with a curing wavelength greater than 430 nm and a curing depth greater than 10 mm.

9. The high impact resistant and high curing depth epoxy adhesive as claimed in claim 7, characterized in that: The high impact resistance and high curing depth epoxy adhesive has a modulus of less than 3.5 GPa.

10. Use of the epoxy adhesive as claimed in claim 7 in the preparation of a flexible circuit board.

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