Method for accelerating curing of oily hydroxyl-containing resin and isocyanate resin mixed glue

Abstract

The invention discloses a method for accelerating curing of oily hydroxyl-containing resin and isocyanate resin mixed glue, which comprises the following steps: (1) brushing, rolling or printing a prime coat connecting layer on the surface of a base layer, the prime coat connecting layer contains a catalyst, and the reaction of hydroxyl resin and isocyanate is promoted through the catalyst; (2) mixed glue of hydroxyl resin and an isocyanate curing agent is coated on the prime coat connecting layer, a catalyst in the prime coat connecting layer is soaked by a solvent in the mixed glue, the catalyst partially permeates into the mixed glue, the prime coat connecting layer is dried to form a coating layer, curing of the mixed glue is accelerated in a continuous heating environment, and the coating layer is formed; therefore, the curing time is shortened, the hardness of the coating is enhanced, and the apparent cohesiveness is improved. According to the technical scheme, the manufacturing cost is low, the curing time is short, the mixed glue of the hydroxyl-containing resin glue and the isocyanate resin is kept relatively stable at normal temperature, and the practicability is good.

Description

Technical Field

[0001] The invention relates to the technical field of resin coating and drying, and in particular to a method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin. Background Art

[0002] The mixed glue of hydroxyl resin and isocyanate is widely used in the coating and coating industry due to its excellent adhesion and weather resistance. However, hydroxyl resin and isocyanate resin can also react slowly at room temperature. The reaction speed can be accelerated by heating, but it takes longer time and higher temperature to react thoroughly. Before the reaction is completed, the coating surface shows a certain degree of adhesion, which is easy to adhere to dust and the finished product is difficult to stack. In order to accelerate the reaction of the mixed glue of hydroxyl resin and isocyanate, a catalyst is generally added to the coating glue to reduce the curing temperature and speed up the curing time. But this will also cause a problem: after the addition of the catalyst, the reaction speed of the glue at room temperature is also accelerated. The amount of glue prepared needs to be accurately controlled according to the production conditions and used up within a certain period of time to ensure the best process state and performance. In order to overcome the disadvantage of poor glue stability at room temperature, people have developed blocked isocyanates to ensure the stability of the prepared glue at room temperature. However, among the same type of isocyanate resins, the cost of blocked isocyanate resins is relatively high. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for accelerating the curing of a mixed glue of oily hydroxyl resin and isocyanate resin, which has low manufacturing cost, short curing time, keeps the mixed glue of hydroxyl resin glue and isocyanate resin relatively stable at room temperature and has good practicality.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin, comprising the following steps: (1) brushing, rolling or printing a primer connecting layer on the surface of the base layer, wherein the primer connecting layer contains a catalyst to promote the reaction between the hydroxyl resin and the isocyanate; (2) A mixed glue of hydroxyl resin and isocyanate curing agent is applied on the primer connecting layer. The catalyst in the primer connecting layer partially penetrates into the mixed glue due to the infiltration of the solvent in the mixed glue. The primer connecting layer is dried to form a coating layer. Under continuous heating, the curing of the mixed glue is accelerated, thereby shortening the curing time, enhancing the hardness of the coating, and improving the apparent adhesion.

[0005] Preferably, the base layer is a paint surface coated with a base resin or a non-coating surface, and the non-coating surface is a PET film surface or an iron plate surface.

[0006] As a preference, the oily hydroxyl-containing resin is an acrylate resin or a polyester resin; the isocyanate resin is biuret, IPDI, HDI or a highly weather-resistant end-NCO grafted modified resin.

[0007] As a preferred embodiment, the catalyst is organic tin, organic bismuth or organic zinc; the content of the catalyst accounts for 0.05-2% of the glue in the primer connecting layer; the drying temperature of the primer connecting layer is 15° C.-150° C.; and the drying time is 0.5-10 min.

[0008] As a preferred embodiment, the primer connecting layer is chloroacetic acid resin, chloroether resin, aldehyde ketone resin, polyvinyl butyral resin, polyester resin or acrylate resin.

[0009] As a preferred embodiment, the thickness of the primer connecting layer is between 0.1 micrometers and 50 micrometers, and the drying temperature of the mixed glue of hydroxyl resin and isocyanate is 70° C.-150° C., and the drying time is 3-8 minutes.

[0010] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention brushes, rolls or prints a primer connecting layer on the surface of the base layer, the primer connecting layer contains a catalyst, and the catalyst is used to promote the reaction of the hydroxyl resin and the isocyanate; a mixed glue of the hydroxyl resin and the isocyanate curing agent is applied on the primer connecting layer, and the catalyst in the primer connecting layer partially penetrates into the mixed glue due to the infiltration of the solvent in the mixed glue, and the primer connecting layer is dried, and the mixed glue is accelerated to cure under a continuous heating environment, thereby shortening the curing time, enhancing the hardness of the coating, and improving the apparent adhesion. In order to accelerate the curing, the mixed glue containing the hydroxyl resin glue and the isocyanate resin is kept relatively stable at room temperature, and the cost can be appropriately controlled, so that the manufacturing cost is low, the curing time is short, and the practicability is good.

[0011] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of coating of an embodiment of the present invention; DETAILED DESCRIPTION

[0013] In the description of this embodiment, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore, cannot be understood as limiting the present invention. In addition, if the terms "first", "second", and "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0014] See also Figure 1 The present invention discloses a method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin, comprising the following steps: (1) brushing, rolling or printing a primer connecting layer 2 on the surface of the base layer 1, wherein the primer connecting layer contains a catalyst 4, and the catalyst 4 promotes the reaction between the hydroxyl resin and the isocyanate; (2) A mixed glue of hydroxyl resin and isocyanate curing agent is applied on the primer connecting layer 2. The catalyst 4 in the primer connecting layer 2 partially penetrates into the mixed glue due to the infiltration of the solvent in the mixed glue. The primer connecting layer 2 is dried to form a coating layer 3. Under continuous heating, the curing of the mixed glue is accelerated, thereby shortening the curing time, enhancing the hardness of the coating, and improving the apparent adhesion.

[0015] The base layer 1 is a car paint surface coated with a base resin or a non-coating surface, and the non-coating surface is a PET film surface or an iron plate surface.

[0016] The oily hydroxyl-containing resin is an acrylate resin or a polyester resin; the isocyanate resin is a biuret, IPDI, HDI or a highly weather-resistant end-NCO grafted modified resin.

[0017] The catalyst 4 is organic tin, organic bismuth or organic zinc; the content of the catalyst 4 accounts for 0.05-2% of the glue in the primer connecting layer; the drying temperature of the primer connecting layer 2 is 15° C.-150° C.; the drying time is 0.5-10 min.

[0018] The primer connecting layer 2 is chloroacetic acid resin, chloroether resin, aldehyde ketone resin, polyvinyl butyral resin, polyester resin or acrylate resin.

[0019] The thickness of the primer connecting layer 2 is between 0.1 micrometers and 50 micrometers, and the drying temperature of the mixed glue of hydroxyl resin and isocyanate is 70° C.-150° C., and the drying time is 3-8 minutes.

[0020] In actual application, a protective layer is applied on the surface of PET to improve weather resistance. A primer connection layer (VC40 chloroether resin, 20% solid content) is printed by gravure printing. 0.8% of dibutyltin dilaurate is added as a catalyst in 100 parts. After drying, a mixed resin of hydroxy acrylate resin and isocyanate resin is applied (B86 resin and HDI biuret are mixed at a ratio of 100:15, and 5 parts of ethyl acetate are added, totaling 120 parts). The mixture is dried at 90°C for 2 minutes, and then at 145°C for 3 minutes. The coating thickness after glue drying is 20 microns, and the surface is non-adhesive. If there is no printed connection layer, it takes 145°C to dry for 120 minutes to achieve the effect of non-adhesive surface. If 0.2 parts of catalyst are added directly to 120 parts of the mixed glue of B86 and HDI biuret, the effective use time of the mixed resin at room temperature is shortened from 15 hours without catalyst to 3 hours with catalyst.

[0021] The above technical scheme, brush, roll or print a layer of primer connecting layer on the surface of the base layer, the primer connecting layer contains a catalyst, and the catalyst is used to promote the reaction of hydroxyl resin and isocyanate; a mixed glue of hydroxyl resin and isocyanate curing agent is applied on the primer connecting layer, the catalyst in the primer connecting layer is infiltrated by the solvent in the mixed glue, and the catalyst partially penetrates into the mixed glue, and the primer connecting layer is dried, and the mixed glue is accelerated in a continuously heated environment, thereby shortening the curing time, enhancing the coating hardness, and improving the apparent adhesion. In order to accelerate the curing, the mixed glue containing hydroxyl resin glue and isocyanate resin is kept relatively stable at room temperature, and the cost can be properly controlled, so that the manufacturing cost is low, the curing time is short and the practicability is good. The specific description of the present invention in the above embodiment is only used to further illustrate the present invention, and cannot be understood as limiting the scope of protection of the present invention. Technical engineers in this field make some non-essential improvements and adjustments to the present invention based on the content of the above invention, which fall within the scope of protection of the present invention.

Claims

1. A method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin, characterized in that: The following steps are involved: (1) brushing, rolling or printing a primer connecting layer on the surface of the base layer, wherein the primer connecting layer contains a catalyst to promote the reaction between the hydroxyl resin and the isocyanate; (2) A mixed glue of hydroxyl resin and isocyanate curing agent is applied on the primer connecting layer. The catalyst in the primer connecting layer partially penetrates into the mixed glue due to the infiltration of the solvent in the mixed glue. The primer connecting layer is dried to form a coating layer. Under continuous heating, the curing of the mixed glue is accelerated, thereby shortening the curing time, enhancing the hardness of the coating, and improving the apparent adhesion.

2. The method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin according to claim 1, characterized in that: The base layer is a car paint surface coated with a base resin or a non-coating surface, and the non-coating surface is a PET film surface or an iron plate surface.

3. The method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin according to claim 2, characterized in that: The oily hydroxyl-containing resin is an acrylate resin or a polyester resin; the isocyanate resin is a biuret, IPDI, HDI or a highly weather-resistant end-NCO grafted modified resin.

4. The method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin according to claim 3, characterized in that: The catalyst is organic tin, organic bismuth or organic zinc; the content of the catalyst accounts for 0.05-2% of the glue in the primer connecting layer; the drying temperature of the primer connecting layer is 15° C.-150° C.; and the drying time is 0.5-10 minutes.

5. The method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin according to claim 4, characterized in that: The primer connecting layer is chloroacetic acid resin, chloroether resin, aldehyde ketone resin, polyvinyl butyral resin, polyester resin or acrylate resin.

6. The method for accelerating the curing of a mixed glue of an oily hydroxyl-containing resin and an isocyanate resin according to claim 5, characterized in that: The thickness of the primer connecting layer is between 0.1 micrometers and 50 micrometers, and the drying temperature of the mixed glue of hydroxyl resin and isocyanate is 70° C.-150° C., and the drying time is 3-8 minutes.

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