TWI848672B - Self-healing polyurethane resin coating material for paint protection film and manufacturing method thereof - Google Patents

Abstract

A self-healing polyurethane resin coating material for paint protection film and manufacturing method thereof are provided. The coating material is formed by a covalent cross-linking reaction of a main agent and a hardener. The main agent is formed by reacting a polyester polyol, a first isocyanate component, and a bisphenol compound. The hardener includes: a second isocyanate component, a bridging agent component and a catalyst component mixed with each other. The covalent bonds of the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, thereby exhibiting a softened and fluid state.

Description

Self-repairing polyurethane resin coating material for car cover film and its manufacturing method

The present invention relates to a resin coating material, in particular to a self-repairing polyurethane resin coating material for car cover film and a manufacturing method thereof.

Paint protection film refers to the use of colored or colorless film materials to cover part or all of the car body with a delicate process, so that the car body can achieve physical protection, sweat resistance, increase the convenience of cleaning, and better maintenance. At the same time, it can also protect the car paint and the car body from being damaged by gravel or stones on the road when driving at high speed. However, the existing car film still has many shortcomings in terms of material properties. For example, scratches formed by scratches on the car film are difficult to repair.

Therefore, the inventors of the present invention felt that the above defects could be improved, and therefore conducted intensive research and applied scientific principles, and finally proposed the present invention which has a reasonable design and effectively improves the above defects.

The technical problem to be solved by the present invention is to provide a self-repairing polyurethane resin coating material for car cover film and a manufacturing method thereof in view of the shortcomings of the prior art.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a method for manufacturing a self-repairing polyurethane resin coating material for car cover film, which comprises: performing a main agent preparation operation, which includes: subjecting a diol component and a dibasic acid component to a first synthesis reaction to form a polyester polyol; subjecting the polyester polyol to a second synthesis reaction with a first isocyanate component to form an intermediate compound having a carbamate structure; and further subjecting the intermediate compound to a third synthesis reaction with a bisphenol compound to form a main agent. A hardener preparation operation is performed, which includes: mixing a second isocyanate component, a bridging agent component, and a catalyst component to form a hardener; and a coating preparation operation is performed, which includes: mixing the main agent and the hardener to form a coating liquid; then the coating liquid is coated and subjected to a covalent crosslinking reaction and hardened to form a polyurethane resin coating material; wherein the covalent bonds in the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, thereby presenting a softened and flowable state.

Preferably, in the main agent preparation process, the diol component is selected from at least one of the material group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol; wherein the dibasic acid component is selected from at least one of the material group consisting of phthalic acid, adipic acid, and halogenated phthalic acid; wherein the diol component and the dibasic acid component are subjected to the first synthesis reaction at a synthesis temperature between 120°C and 220°C to form the polyester polyol.

Preferably, in the main agent preparation operation, the first isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and diphenylmethane diisocyanate (MDI); wherein the bisphenol compound is selected from at least one of the material group consisting of bisphenol A, bisphenol B, bisphenol C, bisphenol E, and bisphenol F.

Preferably, the main agent is a polymer compound, and a weight average molecular weight of the main agent is between 25,000 g/mol and 80,000 g/mol; wherein the main chain constituting the polymer structure of the main agent is the polyester polyol and the first isocyanate component, and the main agent has an excess of hydroxyl groups (-OH groups) at the end of the polymer structure through the introduction of the bisphenol compound, and has a resonant structure; wherein, in the main agent, a molar ratio of the polyester polyol: the first isocyanate component: the bisphenol compound is 1~1.5:1~2:1~2.

Preferably, in the hardener preparation process, the second isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI); wherein the bridging agent component is selected from hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane The present invention relates to a hardener comprising at least one of a material group consisting of a diisocyanate urea ketone trimer; wherein the catalyst component is selected from at least one of a material group consisting of a tin catalyst, a titanium catalyst, a bismuth catalyst, and a zinc catalyst; wherein in the hardener, a weight ratio of the second isocyanate component: the bridge component: the catalyst component is 3-5:1-3:1-2.

Preferably, the predetermined high temperature is between 80°C and 100°C, and the predetermined time is between 5 minutes and 20 minutes.

Preferably, in the coating preparation process, a weight ratio of the main agent to the hardener is between 10-20:1-2; wherein a coating thickness of the polyurethane resin coating material is between 5 microns and 35 microns.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a self-repairing polyurethane resin coating material for car cover film, which is formed by a main agent and a hardener through a covalent crosslinking reaction and hardening; wherein the main agent is formed by a synthetic reaction of a polyester polyol, a first isocyanate component, and a diphenol compound; the polyester polyol is formed by a synthetic reaction of a diol component and a dibasic acid component; wherein the hardener comprises a second isocyanate component, a bridging agent component, and a catalyst component mixed with each other; wherein the covalent bonds in the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, thereby presenting a softened and fluid state.

Preferably, in the main agent, the diol component is selected from at least one of the material group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol; the dibasic acid component is selected from at least one of the material group consisting of phthalic acid, adipic acid, and halogenated phthalic acid; the first isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and diphenylmethane diisocyanate (MDI); wherein the bisphenol compound is selected from at least one of the material group consisting of bisphenol A, bisphenol B, bisphenol C, bisphenol E, and bisphenol F; wherein a weight average molecular weight of the main agent is between 25,000 and 1000. g/mol to 80,000 g/mol; wherein the main chain of the polymer structure constituting the main agent is the polyester polyol and the first isocyanate component, and the main agent has an excess of hydroxyl groups (-OH groups) at the end of the polymer structure through the introduction of the bisphenol compound, and has a resonant structure; in the main agent, the molar ratio of the polyester polyol: the first isocyanate component: the bisphenol compound is 1~1.5:1~2:1~2.

Preferably, in the curing agent, the second isocyanate component is at least one of a material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI); wherein the bridging agent component is at least one of a material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane diisocyanate (MDI). The catalyst component is selected from at least one of the material groups consisting of: a tin catalyst, a titanium catalyst, a bismuth catalyst, and a zinc catalyst; wherein a weight ratio of the second isocyanate component: the bridge component: the catalyst component is 3-5:1-3:1-2.

Preferably, a weight ratio of the main agent to the hardener is between 10-20:1-2; wherein a coating thickness of the polyurethane resin coating material is between 5 microns and 35 microns.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a polyurethane resin coating material, which includes: a main agent, the main agent is formed by a synthesis reaction of a polyester polyol, a first isocyanate component, and a bisphenol compound; the polyester polyol is formed by a synthesis reaction of a diol component and a dibasic acid component; and a hardener, the hardener includes a second isocyanate component, a bridge agent component, and a catalyst component mixed with each other; wherein the main agent and the hardener are stored separately from each other when not in use, and are mixed with each other to perform a covalent crosslinking reaction when in use.

One of the beneficial effects of the present invention is that the self-repairing polyurethane resin coating material for car cover film and the manufacturing method thereof provided by the present invention can enable the polyurethane resin coating material to have the function of reversible covalent self-repairing through the technical solutions of "material preparation of the main agent" and "material preparation of the hardener".

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is a specific embodiment to illustrate the implementation method disclosed by the present invention. The technical personnel in this field can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments. The details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only for simple schematic illustration and are not depicted according to actual size. Please note in advance. The following implementation method will further explain the relevant technical content of the present invention in detail, but the disclosed content is not used to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. may be used in this document to describe various materials or parameters, these materials or parameters should not be limited by these terms. These terms are mainly used to distinguish one material from another material, or one parameter from another parameter. In addition, the term "or" used in this document may include any one or more combinations of the related listed items depending on the actual situation.

[Manufacturing method of self-repairing polyurethane resin coating material for car cover film]

Referring to FIG. 1 , the present invention provides a method for manufacturing a self-repairing polyurethane resin coating material for a car cover film. The manufacturing method comprises steps S110, S120, and S130.

It should be noted that the sequence of steps and the actual operation method described in this embodiment can be adjusted as needed, and the present invention is not limited to the steps described in this embodiment.

The step S110 is to implement a main agent preparation process, and the main agent preparation process includes step S111, step S112, and step S113.

The step S111 includes: subjecting a diol component and a dibasic acid component to a first synthesis reaction (eg, esterification reaction and polycondensation reaction) to form a polyester polyol.

The diol component may be, for example, at least one selected from the group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol. In one embodiment of the present invention, the diol component may be, for example, methyl propanediol, but the present invention is not limited thereto.

The dibasic acid component may be, for example, at least one selected from the group consisting of terephthalic acid, hexanedioic acid, and halophthalic acid. In one embodiment of the present invention, the dibasic acid component may be, for example, adipic acid, but the present invention is not limited thereto.

The diol component and the dibasic acid component are subjected to the first synthesis reaction at a synthesis temperature between 120°C and 220°C, and preferably between 140°C and 200°C.

It is worth mentioning that the polyester polyol formed in step S111 has an excess of hydroxyl groups (-OH groups). In other words, the molecular structure of the polyester polyol has more hydroxyl groups at its end.

Next, the step S112 comprises: subjecting the polyester polyol formed in the step S111 to a second synthesis reaction with a first isocyanate component to form an intermediate compound. Specifically, in the step S112, the excess hydroxyl group on the polyester polyol reacts with the isocyanate group (-NCO group) of the first isocyanate component to form the intermediate compound having a carbamate structure.

The first isocyanate component may be, for example, at least one selected from the group consisting of hexamethylene di-isocyanate (HDI), 4,4'-diisocyanato dicyclohexylmethane (HMDI) and methylene diphenyl di-isocyanate (MDI).

In one embodiment of the present invention, the first isocyanate component may be, for example, hexamethylene diisocyanate (HDI), but the present invention is not limited thereto.

It is worth mentioning that the intermediate compound formed in step S112 has an excess of isocyanate groups (-NCO groups). In other words, the terminal of the molecular structure of the intermediate compound has more isocyanate groups.

Next, the step S113 comprises: further subjecting the intermediate compound having a carbamate structure formed in the step S112 to a third synthesis reaction with a bisphenol compound to form a main agent (also referred to as agent A).

Specifically, in the step S113, the excess isocyanate group on the intermediate compound reacts with the hydroxyl group (-OH group) of the bisphenol compound to complete the preparation of the main agent.

The bisphenol compound may be, for example, bisphenol A (also known as bisphenol methane, bisphenol A, BPA), but the present invention is not limited thereto. The bisphenol compound may also be other bisphenol compounds with similar structures.

For example, the bisphenol compound may be at least one selected from the group consisting of bisphenol A, bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), and bisphenol F (BPF).

It is worth mentioning that the main agent formed in step S113 has an excess of hydroxyl groups (-OH groups). In other words, the terminal reaction site of the molecular structure of the main agent has more hydroxyl groups.

The main agent is a polymer compound, and the main chain of the polymer structure of the main agent is the polyester polyol and the first isocyanate component (such as HDI), and the main agent has excessive/multiple hydroxyl groups (-OH groups) at the terminal reaction site of the polymer structure through the introduction of the bisphenol compound (such as bisphenol A), and can have a resonant structure. Thus, the main agent formed by the step S110 can provide a reversible covalent self-repairing function.

In some embodiments of the present invention, the weight average molecular weight (Mw) of the main agent is preferably between 25,000 g/mol and 80,000 g/mol, and particularly preferably between 28,000 g/mol and 77,000 g/mol.

In some embodiments of the present invention, the molar ratio of the polyester polyol, the first isocyanate component (such as HDI), and the bisphenol compound (such as bisphenol A) in the main agent may be [polyester polyol: first isocyanate component: bisphenol compound] = [1~1.5:1~2:1~2], for example, [1:2:2] or [1:1.5:1.5] or [1.5:1:1].

According to the above configuration, the material characteristics of the main agent can make the finally formed polyurethane resin coating material have excellent self-repairing effect.

Please continue to refer to FIG. 1 , the step S120 is to implement a hardener preparation operation, which includes: mixing a second isocyanate component, a bridge agent component, and a catalyst component to form a hardener (also referred to as agent B).

The second isocyanate component may be, for example, at least one selected from the group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI).

In one embodiment of the present invention, the second isocyanate component may be, for example, hexamethylene diisocyanate (HDI), but the present invention is not limited thereto.

The bridge agent component (also referred to as a crosslinking agent component) may be, for example, at least one of a material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-MDI uretidinone trimer. The bridge agent component has a highly active isocyanate group (-NCO), which can generate a bridge reaction in a synthesis reaction.

In one embodiment of the present invention, the crosslinking agent component may be, for example, a trimer of hexamethylene diisocyanate (HDI-trimer), but the present invention is not limited thereto.

Furthermore, the catalyst component may be, for example, a metal catalyst or an organic metal catalyst. In one embodiment of the present invention, the catalyst component may be, for example, at least one of a material group consisting of a tin catalyst, a titanium catalyst, a bismuth catalyst, and a zinc catalyst, but the present invention is not limited thereto. In one embodiment of the present invention, the catalyst component may be, for example, a tin catalyst (e.g., dibutyltin dilaurate), but the present invention is not limited thereto.

In some embodiments of the present invention, a weight ratio of the second isocyanate component (e.g., HDI), the crosslinker component (e.g., HDI-trimer), and the catalyst component (e.g., tin catalyst) in the hardener may be, for example, [second isocyanate component:crosslinker component:catalyst component] = [3~5:1~3:1~2], for example, [3:3:1].

In the embodiment of the present invention, the bridging agent component (such as HDI-trimer) is used to adjust the soft segment ratio and bridging degree of the polyurethane coating. More specifically, reducing the amount of the bridging agent component can increase the soft segment ratio and reduce bridging, and the hardener within the above-mentioned dosage ratio range can make the final polyurethane coating have a better self-repairing effect.

Please continue to refer to FIG. 1 . The step S130 is to implement a coating preparation operation, which includes: mixing the main agent (also referred to as agent A) prepared in the step S110 and the hardener (also referred to as agent B) prepared in the step S120 to form a coating liquid; then, applying the coating liquid and subjecting it to a covalent cross-linking reaction to form a polyurethane resin coating material.

In an embodiment of the present invention, the coating liquid formed by mixing the main agent and the hardener can be coated on a base film layer of a paint protection film to form a polyurethane resin coating material on the base film layer. Alternatively, the coating liquid can also be coated on a polyurethane (PU) skin.

According to the above configuration, the polyurethane resin coating material can have a reversible covalent self-healing function. More specifically, the main agent (ie, agent A) and the hardener (ie, agent B) will begin to produce a covalent cross-linking reaction after mixing, so that the coating hardens.

The polyurethane resin coating material is heated at a predetermined high temperature (e.g., 80-100° C.) for a predetermined time (e.g., 5-20 minutes) to at least partially break the covalent bonds in the polyurethane resin coating material (e.g., at least 50% broken), so that the coating presents a softened and fluid state, thereby achieving a scratch self-repairing effect. As described above, the main agent can have an excess of hydroxyl groups (-OH groups) at the end of the polymer structure and a resonant structure through the introduction of the above-mentioned bisphenol compound (e.g., bisphenol A). Thereby, the main agent can provide a reversible covalent self-repairing function in the polyurethane resin coating material.

That is, when the polyurethane resin coating material is scratched and forms a scratch, the scratch of the polyurethane resin coating material can be softened and flowed by heating at a predetermined high temperature (such as 80-100° C.) for a predetermined time (such as 10-20 minutes), so that the scratch can be automatically repaired.

In some embodiments of the present invention, a weight ratio between the main agent (agent A) and the hardener (agent B) may be, for example, [main agent: hardener] = [10~20:1~2], for example, [10:1], [10:2], [15:1], [15:2], [20:1], or [20:2].

In some embodiments of the present invention, the coating thickness of the polyurethane resin coating material may be, for example, between 5 micrometers and 35 micrometers, preferably between 10 micrometers and 30 micrometers, and particularly preferably between 12 micrometers and 18 micrometers, but the present invention is not limited thereto.

[Self-repairing polyurethane coating material for car cover]

The above is a detailed description of the method for manufacturing the self-repairing polyurethane resin coating material for car cover film of an embodiment of the present invention. Another embodiment of the present invention also provides a self-repairing polyurethane resin coating material for car cover film.

The polyurethane resin coating material is formed by a main agent and a hardener through a covalent crosslinking reaction and hardening. The main agent is formed by a polyester polyol, a first isocyanate component, and a diphenol compound undergoing a synthetic reaction. The polyester polyol is formed by a diol component and a dibasic acid component undergoing a synthetic reaction.

In some embodiments of the present invention, the diol component is selected from at least one of the material group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol. The dibasic acid component is selected from at least one of the material group consisting of phthalic acid, adipic acid, and halogenated phthalic acid. The first isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and diphenylmethane diisocyanate (MDI). The bisphenol compound is selected from at least one of the material group consisting of bisphenol A, bisphenol B, bisphenol C, bisphenol E, and bisphenol F. The weight average molecular weight of the main agent is between 25,000 and 80,000 g/mol.

The main chain of the polymer structure of the main agent is polyester polyol and the first isocyanate component. The main agent has an excess of hydroxyl groups (-OH groups) at the reaction site at the end of the polymer structure and has a resonant structure through the introduction of the bisphenol compound. In the main agent, the molar ratio of polyester polyol: first isocyanate component: bisphenol compound is 1-1.5: 1-2: 1-2.

The hardener comprises a second isocyanate component, a bridge component, and a catalyst component which are mixed with each other. In some embodiments of the present invention, the second isocyanate component is at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI). The bridge component is at least one of the material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane diisocyanate ureidinone trimer. In addition, the catalyst component is at least one selected from the group consisting of tin catalyst, titanium catalyst, bismuth catalyst, and zinc catalyst. The weight ratio of the second isocyanate component: the bridge component: the catalyst component is 3-5:1-3:1-2.

In some embodiments of the present invention, a weight ratio of the main agent to the hardener is between 10-20:1-2. In addition, a coating thickness of the polyurethane resin coating material is between 5 microns and 35 microns.

The covalent bonds in the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, thereby presenting a softened and fluid state.

It is worth mentioning that although the embodiment of the present invention mixes the main agent (agent A) and the hardener (agent B) to form a coating, the present invention is not limited thereto.

For example, the main agent (agent A) and the hardener (agent B) in the polyurethane resin coating material can be stored separately from each other when not in use, and are mixed and applied when needed to perform a covalent cross-linking reaction.

[Experimental data and test results]

Hereinafter, the contents of the present invention will be described in detail with reference to Examples 1 to 3 and Comparative Example 1. However, the following examples are only provided to help understand the present invention, and the scope of the present invention is not limited to these examples.

Example 1: Methyl propanediol and adipic acid are subjected to esterification and polycondensation to form a polyester polyol (Mn = 4,000 g/mol); the polyester polyol is subjected to synthesis reaction with isocyanate HDI, and further subjected to synthesis reaction with bisphenol A to complete the preparation of the main agent. The molar ratio of polyester polyol: HDI: bisphenol A is 1:2:2. The weight average molecular weight of the main agent is 41,000 g/mol. Then, isocyanate HDI, bridge agent HDI-trimer, and tin catalyst (dibutyltin dilaurate) are mixed in a weight ratio of 3:3:1 to complete the preparation of the hardener. Finally, 15 parts by weight of the main agent and 1 part by weight of the hardener are mixed to form a coating liquid, and the coating liquid is applied on the PU skin to form a polyurethane resin coating layer having a coating thickness of about 15 microns.

Example 2: The preparation conditions are substantially the same as those of Example 1, except that in the preparation of the main agent, the molar ratio of polyester polyol: HDI: bisphenol A is 1:1.5:1. The weight average molecular weight of the main agent is 77,000 g/mol. The remaining conditions of Example 2 are the same as those of Example 1.

Example 3: The preparation conditions are substantially the same as those of Example 1, except that in the preparation of the main agent, the molar ratio of polyester polyol: HDI: bisphenol A is 1.5:2:1. The weight average molecular weight of the main agent is 28,000 g/mol. The remaining conditions of Example 3 are the same as those of Example 1.

Comparative Example 1: The biggest difference from Example 1 is that bisphenol A is not used in the main agent. In the preparation of the main agent, the molar ratio of polyester polyol: HDI: bisphenol A is 1:1.5:0. The weight average molecular weight of the main agent is 16,200.

Next, the self-repairing effect of the polyurethane resin coatings prepared in Examples 1 to 3 and Comparative Example 1 was tested. The test method includes: forming a scratch (e.g., a scratch with a length of 5 to 15 cm and a depth of 5 to 12 μm) on the surface of the polyurethane resin coating, and then baking the polyurethane resin coating at a heating temperature (e.g., 80 to 100° C.) for a period of time to observe under what conditions the scratch can be repaired or cannot be repaired.

[Table 1 Experimental conditions and test results] Embodiment 1 Embodiment 2 Embodiment 3 Comparison Example 1 [Main agent] Polyester polyol: HDI: Bisphenol A (molar ratio) 1:2:2 1:1.5:1 1.5:2:1 1:1.5:0 Weight average molecular weight of main agent (g/mol) 41000 77000 28000 16200 [Hardener] HDI: HDI-trimer: tin catalyst (weight ratio) 3:3:1 3:3:1 3:3:1 3:3:1 [Coating liquid] Weight ratio of main agent and hardener 15:1 15:1 15:1 15:1 Coating thickness (micrometers) 15 15 15 15 Self-repair effect ranking 2 1(lowest temperature) 3 NA Self-repairing effect of coating (heat repair temperature and time of scratches) 90℃*10min can be repaired 80℃*10min can be repaired 100℃*10min can be repaired 120℃*10min cannot be repaired

It can be seen from the experimental results that the scratches on the polyurethane resin coating of Example 1 can be repaired by baking at a heating temperature of 90°C for 10 minutes. The scratches on the polyurethane resin coating of Example 2 can be repaired by baking at a heating temperature of 80°C for 10 minutes. The scratches on the polyurethane resin coating of Example 3 can be repaired by baking at a heating temperature of 100°C for 10 minutes. That is to say, ranked according to the repair effect, Example 2 has the best repair effect because it only needs to be baked at a heating temperature of 80°C for 10 minutes to complete the thermal repair. Figure 2 is an experimental photograph of the polyurethane resin coating surface of Example 2 with scratches, and Figure 3 is an experimental photograph of the polyurethane resin coating surface of Figure 2 after thermal repair. The heat repair condition is 80℃*10min. As shown in Figure 3, the scratches on the surface of the polyurethane resin coating (as shown in Figure 2) have been successfully repaired after heat repair (as shown in Figure 3).

Furthermore, since Comparative Example 1 does not use bisphenol A as the main agent, the scratches on the polyurethane resin coating of Comparative Example 1 cannot be repaired even though it is baked at a high temperature of 120° C. for 10 minutes.

[Beneficial Effects of Embodiments]

One of the beneficial effects of the present invention is that the self-repairing polyurethane resin coating material for car cover film and the manufacturing method thereof provided by the present invention can enable the polyurethane resin coating material to have a reversible covalent self-repairing function (such as: baking at 80°C for 10 minutes to restore to the original scratch-free state) through the technical solutions of "material preparation of the main agent" and "material preparation of the hardener".

Furthermore, the polyurethane resin coating material provided by the embodiment of the present invention can resist scratches such as those caused by keys, and can achieve a self-repairing effect, and the repairing effect can be repeated and convenient (such as using heat repair). In addition, the polyurethane resin coating material has high light transmittance, transparent color, and low surface gloss, and has basic anti-fouling and anti-scratch properties.

The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

FIG. 1 is a flow chart of a method for manufacturing a self-repairing polyurethane resin coating material for a car cover film according to an embodiment of the present invention.

FIG. 2 and FIG. 3 are experimental photographs of the polyurethane resin coating of the embodiment of the present invention.

Claims (12)

A method for manufacturing a self-repairing polyurethane resin coating material for car cover film, comprising: performing a main agent preparation operation, which includes: subjecting a diol component and a dibasic acid component to a first synthesis reaction to form a polyester polyol; performing a second synthesis reaction on the polyester polyol and a first isocyanate component to form an intermediate compound having a urethane structure; and further performing a third synthesis reaction on the intermediate compound and a bisphenol compound to form a main agent; performing a hardener preparation operation, which includes: mixing a second isocyanate component, a bridge agent component, and a catalyst component to form a hardener; wherein the bridge agent component is a catalyst component; and the bridge agent component is a catalyst component. The bridging agent component is selected from at least one of the material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane diisocyanate ureidinone trimer; and a coating preparation operation is performed, which includes: mixing the main agent and the hardener to form a coating liquid; then applying the coating liquid and subjecting it to a covalent crosslinking reaction and hardening to form a polyurethane resin coating material; wherein the covalent bonds in the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, so that the polyurethane resin coating material is softened and flowable. The manufacturing method as described in claim 1, wherein, in the main agent preparation operation, the diol component is selected from at least one of the material group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol; wherein the dibasic acid component is selected from at least one of the material group consisting of phthalic acid, adipic acid, and halogenated phthalic acid; wherein the diol component and the dibasic acid component are subjected to the first synthesis reaction at a synthesis temperature between 120°C and 220°C to form the polyester polyol. The manufacturing method as described in claim 1, wherein, in the main agent preparation operation, the first isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and diphenylmethane diisocyanate (MDI); wherein the bisphenol compound is selected from at least one of the material group consisting of bisphenol A, bisphenol B, bisphenol C, bisphenol E, and bisphenol F. The manufacturing method as described in claim 1, wherein the main agent is a polymer compound, and the weight average molecular weight of the main agent is between 25,000 g/mol and 80,000 g/mol; wherein the main chain constituting the polymer structure of the main agent is the polyester polyol and the first isocyanate component, and the main agent has an excess of hydroxyl groups (-OH groups) at the end of the polymer structure through the introduction of the bisphenol compound, and has a resonant structure; wherein, in the main agent, the molar ratio of the polyester polyol: the first isocyanate component: the bisphenol compound is 1~1.5:1~2:1~2. The manufacturing method as described in claim 1, wherein, in the hardener preparation operation, the second isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI); wherein the catalyst component is selected from at least one of the material group consisting of tin catalyst, titanium catalyst, bismuth catalyst and zinc catalyst; wherein in the hardener, the weight ratio of the second isocyanate component: the bridge component: the catalyst component is 3~5:1~3:1~2. A manufacturing method as described in claim 1, wherein the predetermined high temperature is between 80°C and 100°C, and the predetermined time is between 5 minutes and 20 minutes. The manufacturing method as described in claim 1, wherein in the coating preparation operation, a weight ratio between the main agent and the hardener is between 10~20:1~2; wherein a coating thickness of the polyurethane resin coating material is between 5 microns and 35 microns. A self-repairable polyurethane resin coating material for car cover film, which is formed by a main agent and a hardener through a covalent crosslinking reaction and hardening; wherein the main agent is formed by a synthetic reaction of a polyester polyol, a first isocyanate component, and a bisphenol compound; the polyester polyol is formed by a synthetic reaction of a diol component and a dibasic acid component; wherein the hardener contains a second isocyanate component, a bridging agent, and a second isocyanate component mixed with each other. component, and a catalyst component; wherein the bridging agent component is selected from at least one of the material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane diisocyanate ureidinone trimer; wherein the covalent bonds in the polyurethane resin coating material are at least partially broken when heated at a predetermined high temperature for a predetermined time, so that the polyurethane resin coating material is softened and flowable. The polyurethane resin coating material as described in claim 8, wherein in the main agent, the diol component is selected from at least one of the material group consisting of ethylene glycol, propylene glycol, methyl propanediol, pentaerythritol, and 1,4-butanediol; the dibasic acid component is selected from at least one of the material group consisting of phthalic acid, adipic acid, and halogenated phthalic acid; the first isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and diphenylmethane diisocyanate (MDI); wherein the bisphenol compound is selected from bisphenol A , bisphenol B, bisphenol C, bisphenol E, and bisphenol F, at least one of the material group; wherein the weight average molecular weight of the main agent is between 25,000 g/mol and 80,000 g/mol; wherein the main chain of the polymer structure of the main agent is the polyester polyol and the first isocyanate component, and the main agent has an excess of hydroxyl groups (-OH groups) at the end of the polymer structure through the introduction of the bisphenol compound, and has a resonant structure; in the main agent, the molar ratio of the polyester polyol: the first isocyanate component: the bisphenol compound is 1~1.5:1~2:1~2. The polyurethane resin coating material as described in claim 8, wherein in the hardener, the second isocyanate component is selected from at least one of the material group consisting of hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and diphenylmethane diisocyanate (MDI); wherein the catalyst component is selected from at least one of the material group consisting of tin catalyst, titanium catalyst, bismuth catalyst and zinc catalyst; wherein the weight ratio of the second isocyanate component: the bridge component: the catalyst component is 3~5:1~3:1~2. The polyurethane resin coating material as described in claim 8, wherein the weight ratio between the main agent and the hardener is between 10~20:1~2; wherein the coating thickness of the polyurethane resin coating material is between 5 microns and 35 microns. A self-repairable polyurethane resin coating material for car cover film, comprising: a main agent, the main agent is formed by a synthetic reaction of a polyester polyol, a first isocyanate component, and a bisphenol compound; the polyester polyol is formed by a synthetic reaction of a diol component and a dibasic acid component; and a hardener, the hardener comprises a second isocyanate component, a bridge component, and a catalyst component mixed with each other; wherein the bridge component is selected from at least one of the material group consisting of hexamethylene diisocyanate trimer (HDI-trimer) and 4,4-diphenylmethane diisocyanate ureidinone trimer; wherein the main agent and the hardener are stored separately from each other when not in use, and are mixed with each other to perform a covalent crosslinking reaction when in use.