CN-121991356-A - Modifier and epoxy resin condensate, preparation method thereof and application thereof in cover surface of image capturing device

Abstract

The invention discloses a modifier for toughening epoxy resin, which is characterized in that the modifier is a blend composed of epoxy group partially end-capped polydimethylsiloxane and bisphenol A epoxy resin, and the content of the bisphenol A epoxy resin in the modifier is more than 10%. The invention also discloses a preparation method of the modifier, an epoxy resin condensate adopting the modifier, a preparation method of the epoxy resin condensate and application of the epoxy resin condensate in an image capturing device cover surface. Compared with the prior art, the modifier can improve the toughness, impact strength and tensile strength of the epoxy resin cured product and can be stored for a long time.

Inventors

• XIN FENGGUANG
• TU YINGFENG
• YANG YUXIN
• CHEN PENG
• LU HUA

Assignees

• 宁波堇山新材料有限公司
• 宁波堇天材料科技有限公司

Dates

Publication Date

20260508

Application Date

20260410

Claims (10)

1. 1. A modifier for toughening epoxy resin is characterized in that the modifier is a blend composed of epoxy group partially end-capped polydimethylsiloxane and bisphenol A type epoxy resin, and the epoxy group partially end-capped polydimethylsiloxane has a general formula: wherein n is 6 to 40, the sum of a and b is 2 and a <1.5; the content of the bisphenol A type epoxy resin in the modifier is more than 10 percent.
2. 2. A preparation method of the modifier of claim 1, which is characterized by comprising the steps of dissolving aminopropyl terminated polydimethylsiloxane and bisphenol A epoxy resin in a solvent, heating to react, controlling the reaction temperature to be 40-60 ℃, controlling the reaction concentration to be 0.1-0.5 g/mL, and the reaction time to be 1-18 h; The feeding mole ratio of the amino group to the epoxy group of the aminopropyl terminated polydimethylsiloxane to the bisphenol A epoxy resin is 1:1-1:20.
3. 3. The method of claim 2, wherein the aminopropyl terminated polydimethylsiloxane has a molecular weight ranging from 600 g/mol to 3000 g/mol.
4. 4. The method according to claim 2, wherein the bisphenol A type epoxy resin has an epoxy value of 0.1 to 0.6; The bisphenol A type epoxy resin is at least one of BE-188EL, E-51, E-44, E-20 and E-12.
5. 5. The method of claim 2, wherein the solvent is at least one of dichloromethane, chloroform, tetrahydrofuran and toluene.
6. 6. An epoxy resin cured product using the modifier according to claim 1, wherein said epoxy resin cured product is obtained by adding said modifier to an epoxy resin and curing.
7. 7. A method for preparing an epoxy resin cured product according to claim 6, which comprises the steps of mixing an epoxy resin with a modifier, adding a curing agent and a defoaming agent, uniformly mixing, and heating for curing to obtain the required epoxy resin cured product.
8. 8. The method according to claim 7, wherein the epoxy resin is at least one of bisphenol A type, bisphenol F type, glycidylamine type and alicyclic epoxy resin; The curing agent is at least one of ethylenediamine, diphenylmethane diamine, diethylenetriamine, triethylenetetramine and isophorone diamine; the defoaming agent is at least one of organic silicon defoaming agent, acrylic ester defoaming agent and polyether defoaming agent.
9. 9. Use of the cured epoxy resin of claim 6 on an image capture device cover.
10. 10. The application of claim 9, wherein the image capturing device cover comprises A cover body (1) made of the epoxy resin solidified material, a front side wall mounting hole (11) of the cover body (1) with a hollow interior and an open rear side, and And the transparent panel (2) is arranged in the mounting hole (11) of the cover surface body (1).

Description

Modifier and epoxy resin condensate, preparation method thereof and application thereof in cover surface of image capturing device Technical Field The invention relates to the technical field of epoxy resin, in particular to a modifier for toughening epoxy resin, an epoxy resin condensate, a preparation method thereof and application thereof in an image capturing device cover surface. Background With the rapid development of digital technology, network technology, and the like, concepts of everything interconnection, smart cities, safe cities, and the like are continuously proposed and implemented, and terminal image capturing devices such as cameras and monitors as "eyes" are increasingly becoming important. The terminal image capturing device is arranged at each corner of a city, a district, a garden, a factory and a river, collects real-time images of the areas, provides image data for each department of the society, is used for monitoring natural disasters, monitoring operation of the factory, monitoring natural resources and the like, and provides reference basis for safety of aspects of the society. It can be said that the degree of clear image expression determines the degree of safety of a certain area within a certain range. For the cover of the image capturing device, the cover body is generally made of thermosetting resin. Epoxy resin is one of the most widely used thermosetting materials, has the advantages of high strength and high modulus, low curing shrinkage, good adhesion performance, excellent electrical insulation property, corrosion resistance and the like, and plays an important role in the fields of adhesives, electronic packaging, insulating materials, anticorrosive coatings, aerospace and the like. However, the cured epoxy resin has a highly crosslinked structure, so that the movement of a molecular chain is limited, and the problems of high brittleness, poor cracking resistance, poor shock resistance and the like of the cured epoxy resin exist, which limit the application and development of the epoxy resin. Therefore, toughening modification of epoxy resins has been a research hotspot. The polysiloxane has the advantages of excellent flexibility, high and low temperature resistance, hydrophobicity, weather resistance, chemical stability and the like, and the polysiloxane is used for toughening modification research of epoxy resin, so that the toughness of the epoxy resin cured product can be improved, the overall performance of the epoxy resin cured product can be improved, and the application range of the epoxy resin is further widened. The literature 'preparation and performance research of amino silicone oil modified epoxy resin' (plastics, 2008, 37 (05): 1-3) utilizes amino silicone oil modified epoxy resin, and under the condition that a solvent system is not used, the obtained modified epoxy resin has more holes, is easy to form stress concentration points, and has insignificant improvement of mechanical properties. And adding acetone as a solvent, reacting, removing the solvent, and adding a curing agent to perform injection molding curing to obtain the epoxy resin with obviously improved toughness. However, it is necessary to add a relatively large amount of amino silicone oil (5%), and its molecular weight is relatively low (amino value 0.4 mol/100 g). In addition, the system needs to react at a higher temperature (the temperature of the reaction after adding acetone is 140 ℃ and the boiling point of acetone is only 56 ℃), and the specific mechanism is not particularly clear because primary amine can react with acetone to generate Schiff base or carry out Mannich reaction and also can open ring epoxy resin. Patent CN201410452968.8 discloses a polydimethylsiloxane polymer containing tetraepoxy groups and a preparation method thereof, wherein the polydimethylsiloxane polymer is prepared by reacting amino-terminated polydimethylsiloxane with bisphenol A glycidyl ether, precipitating in frozen acetonitrile, filtering and drying. On one hand, the method has high yield, but consumes a large amount of organic solvent in the preparation process, and is not friendly to the environment. On the other hand, since hydroxyl groups can also initiate ring opening of epoxy groups (but slower than amine groups), the resulting tetrafunctional polydimethylsiloxane has poor product stability and is difficult to store and use because of the high concentration of hydroxyl groups and epoxy end groups, which are prone to react to crosslink. The patent does not describe whether it can toughen and modify the epoxy resin. The literature 'mechanical properties and thermal properties of different side group polysiloxane modified epoxy resins' (thermosetting resins, 2024, 39 (06): 1-7) prepares modified epoxy resins by catalyzing hydroxyl-terminated polydimethylsiloxane and epoxy resins with bismuth isooctanoate. With the increase of the addition amount of the hydroxyl-terminated polydimethylsiloxane, th