CN-122010787-A - Modified dicyandiamide curing agent, preparation method and application

Abstract

The invention discloses a modified dicyandiamide curing agent, a preparation method and application thereof, wherein the modified dicyandiamide curing agent is synthesized by at least 10 to 20 parts by mass of dicyandiamide and 12 to 24 parts by mass of styrene. According to the modified dicyandiamide curing, the dicyandiamide is modified by using the styrene, so that the polarity among molecules of the modified dicyandiamide curing agent is reduced, the distribution of active sites is more uniform, the curing of a cured product is more complete, and the structural consistency is higher. The structure of the styrene enables the modified dicyandiamide curing agent to have larger substituent groups, and the movable rotation capacity of chain links is limited. Short branching increases the chain spacing, increases the free volume, prevents intermolecular slip, and can improve the toughness of the cured product.

Inventors

• WANG YIFANG
• WANG YURONG

Assignees

• 苏州高泰电子技术股份有限公司

Dates

Publication Date

20260512

Application Date

20260130

Claims (10)

1. 1. A modified dicyandiamide curing agent characterized by being synthesized from at least 10 to 20 parts by mass of dicyandiamide and 12 to 24 parts by mass of styrene, the modified dicyandiamide curing agent having a structural formula: 。
2. 2. A method of preparing the modified dicyandiamide curing agent of claim 1, comprising: Weighing 10 to 20 parts by mass of dicyandiamide and dissolving the dicyandiamide in N, N-dimethylformamide to obtain a first reaction liquid; Weighing 12 to 24 parts by mass of styrene and dissolving in toluene to obtain a second reaction solution; dropwise adding the second reaction solution into the first reaction solution in a titration mode, and continuously preserving heat after the dropwise adding is finished to obtain a curing agent solution; And after the reaction of the first reaction liquid and the second reaction liquid is completed, evaporating, cleaning and drying the solvent in the curing agent solution to obtain the modified dicyandiamide curing agent.
3. 3. The method for producing a modified dicyandiamide curing agent according to claim 2, wherein the amount of the N, N-dimethylformamide is 100 to 120 parts by mass.
4. 4. The method for producing a modified dicyandiamide curing agent according to claim 2, wherein the toluene is used in an amount of 100 to 150 parts by mass.
5. 5. The method of preparing a modified dicyandiamide curing agent according to claim 2, wherein the reaction temperature and the holding temperature of the second reaction liquid and the first reaction liquid are 70 to 80 ℃.
6. 6. The method of preparing a modified dicyandiamide curing agent according to claim 2, wherein the second reaction liquid and the first reaction liquid react under ultrasonic conditions.
7. 7. The method of preparing a modified dicyandiamide curing agent according to claim 2, wherein the second reaction liquid has a dropping speed of 30 to 42 drops/min.
8. 8. A method for preparing a non-silicon heat conducting material, comprising the steps of: Mixing 1 to 1.5 parts by mass of the modified dicyandiamide curing agent prepared by the preparation method of any one of claims 3 to 7, 2 to 6 parts by mass of N, N-dimethylformamide, 6 to 10 parts by mass of acrylic resin and 88 to 93 parts by mass of aluminum powder, heating to 95 to 105 ℃ and stirring to obtain a mixture; and uniformly coating the mixture on a release film, and obtaining the non-silicon heat conducting material after shaping.
9. 9. The method of preparing a non-silicon heat conducting material according to claim 8, wherein the acrylic resin is selected from one or more of pure acrylic resin, styrene acrylic resin and silicone acrylic resin.
10. 10. A non-silicon thermally conductive material prepared using the preparation method of claim 9.

Description

Modified dicyandiamide curing agent, preparation method and application Technical Field The invention belongs to the technical field of polymers, and particularly relates to a modified dicyandiamide curing agent, a preparation method and application thereof. Background The acrylic resin has excellent mechanical properties, good weather resistance and electrical insulation, is widely applied to the fields of paint and adhesive, and is one of the most commonly used resins in high-performance resin matrix composite materials. Meanwhile, because the acrylic resin contains carbon-carbon double bonds and ester groups, the acrylic resin has thermosetting property, can form various cured products with excellent performances with various curing agents, catalysts and additives, and can also generate substitution or addition reaction with various compounds containing active hydrogen to form a reticular structure through curing and crosslinking. The acrylic resin can completely avoid the problems of volatilization, overflow and the like of silicone oil of the traditional heat conducting material in the non-silicon heat conducting material, and simultaneously has high compressibility, so that a heat source can be in closer contact with the heat conducting material, and higher deformation is realized. The non-silicon heat conduction material needs to be kept unchanged for 1000 hours at 130 ℃ in the aging process, however, the cross-linked network skeleton is high in rigidity in the curing process, the relative sliding among molecular chains is difficult, the accumulation of internal stress of a coating in the drying process is easy to cause the cracking of the coating, the toughness is relatively poor, the hardness after curing is high, and the non-ideal selection is realized in an application scene needing high impact resistance. At present, toughening agents such as core-shell rubber, thermoplastic resin, hyperbranched resin and the like are mainly introduced to the toughening of acrylic resin, or an interpenetrating network polymer is formed when the acrylic resin is cured, so that the toughening effect is achieved, and the mechanical property is improved. However, most of the toughening processes are complex in operation, high in system viscosity and long in curing time at present, and the application of the toughening materials in non-silicon heat conducting materials is difficult to meet. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Disclosure of Invention The object of the present invention is to provide a modified dicyandiamide curing agent which can make the curing of a cured product more complete and can improve the toughness of the cured product. In order to achieve the above object, a specific embodiment of the present invention provides a modified dicyandiamide curing agent, which is synthesized from at least 10 to 20 parts by mass of dicyandiamide and 12 to 24 parts by mass of styrene, and has a structural formula as follows: 。 the invention further provides a preparation method of the modified dicyandiamide curing agent, which comprises the steps of weighing 10-20 parts by mass of dicyandiamide and dissolving the dicyandiamide in N, N-dimethylformamide to obtain a first reaction solution, weighing 12-24 parts by mass of styrene and dissolving the styrene in toluene to obtain a second reaction solution, dropwise adding the second reaction solution into the first reaction solution in a titration mode, continuously preserving heat after dropwise adding is completed to obtain a curing agent solution, and evaporating, cleaning and drying a solvent in the curing agent solution after the first reaction solution and the second reaction solution react to obtain the modified dicyandiamide curing agent. In one or more embodiments of the present invention, the N, N-dimethylformamide is used in an amount of 100 to 120 parts by mass. In one or more embodiments of the present invention, the toluene is used in an amount of 100 to 150 parts by mass. In one or more embodiments of the present invention, the reaction temperature and the soak temperature of the second reaction liquid and the first reaction liquid are 70 to 80 ℃. In one or more embodiments of the invention, the second reaction liquid and the first reaction liquid react under ultrasonic conditions. In one or more embodiments of the present invention, the second reaction liquid has a dropping speed of 30 to 42 drops/min. Compared with the prior art, the preparation method of the modified dicyandiamide curing agent utilizes styrene to modify dicyandiamide, so that the polarity among molecules of the modified dicyandiamide curing agent is reduced, the distribution of active sites is more uniform, the curing