CN115584195B

CN115584195B - Bicomponent coating for helmet and preparation method thereof

Info

Publication number: CN115584195B
Application number: CN202211238907.2A
Authority: CN
Inventors: 李景菲; 徐芸莉; 沈振; 吴东亮
Original assignee: Zhejiang Academy Of Product Quality And Safety
Current assignee: Zhejiang Academy Of Product Quality And Safety
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2023-09-29
Anticipated expiration: 2042-10-11
Also published as: CN115584195A

Abstract

The application discloses a bi-component coating for a helmet and a preparation method thereof, wherein the bi-component coating comprises a component A and a component B; the component A comprises the following components in parts by weight: 100 parts of hydroxyl acrylic resin, 8-35 parts of polyol resin, 2-12 parts of adhesion promoter, 15-45 parts of organic cold pigment, 40-120 parts of first diluent, and at least one of benzimidazolone pigment and phthalocyanine pigment; the component B comprises the following components: 100 parts of isocyanate curing agent and 40-100 parts of second diluent. According to the bi-component coating disclosed by the application, the organic cold pigment is introduced into the formula, so that the infrared reflectivity of the coating is effectively improved, the infrared heat absorption capacity of the coating is greatly reduced, meanwhile, the coating has good adhesion performance with a helmet substrate by matching with the polyol resin and the adhesion promoter, and has good fusion with a finish paint, and the coating is not easy to fall off after being sprayed.

Description

Bicomponent coating for helmet and preparation method thereof

Technical Field

The application belongs to the technical field of paint preparation, and particularly relates to a bi-component paint for a helmet and a preparation method thereof.

Background

Helmets are a safety guard, which is a relatively common and important guard in modern traffic, and the main purpose of the helmet is to protect the head of a driver and passengers when impacted, to reduce the strong impact force caused by a violent collision or to prevent sharp objects from penetrating the head directly, to prevent or reduce injuries and even save lives. In modern transportation, helmets are used more and more frequently, the use amount of the helmets is increased, and the use and the comfort of the helmets are key factors for the consideration of the existing consumers.

In order to improve the competitiveness of the products, in addition to the basic safety protection performance of the helmet, excellent appearance, durability and wearing comfort of the helmet are required. At present, the helmet shell is mainly made of plastic materials, and mainly comprises acrylonitrile-butadiene-styrene (ABS) resin, ABS and Polycarbonate (PC) alloy, glass fiber composite material, carbon fiber composite material and the like. In order to prolong the service life of composite material products such as helmets and the like and prevent the plastic appearance and mechanical property from being attenuated due to thermal oxidation, the protection of spraying paint is a common means.

In terms of coating adhesion, since plastic materials are low-surface energy substances, if the plastic materials are lower than the surface energy of liquid paint, the paint is difficult to wet the surface, and surface defects and poor adhesion are easily caused, so that the helmet shell coating is generally divided into three layers: priming, intermediate coating and top coating. The primer is mainly used for enhancing the surface energy of plastics, has good transition property and has more polar groups, and aims to form good adhesive force on plastic substrates and have good matching property with the intercoat coating.

In terms of wearing comfort, the spectral band of solar radiation striking the earth's ground is in the range of about 295nm to 2500 nm. A wavelength below 400nm, known as uv light, can lead to degradation of the coating and polymer; the wavelengths from 400nm to 760nm are called visible light; other from 760nm to 2500nm are the infrared regions, where long wavelength light is invisible to the human eye, but this region contains half the energy of sunlight reaching the earth, and infrared light is perceived as heat. Because the helmet is used in outdoor places, the infrared light absorbing capacity of the helmet is converted into heat, and wearing comfort is affected.

The patent CN114181569A (a heat-insulating reflective coating for helmets and a preparation method thereof) provides a method for adding hollow glass microsphere particles coated by aerogel films into basic emulsion to serve as a heat-insulating reflective material, so that the heat-insulating property of the reflective coating for helmets is improved; the patent CN112094542A (a coating for a reflective helmet and a preparation method thereof) provides a coating which takes glass bead powder, aluminum oxide and silicon dioxide as reflective powder, and adds the reflective powder into transparent resin to improve the reflective effect of the coating; CN111876067a provides a cooling composite coating for helmets, which is formed by sequentially coating a heat radiation cooling layer, a near infrared reflecting layer and an anti-contamination varnish layer from inside to outside, wherein the heat radiation cooling layer contains high-heat reflection titanium dioxide and nanometer far infrared powder, the near infrared reflecting layer contains infrared high-reflection black pigment and high-reflection silver flash slurry, the infrared high-reflection black pigment is black perylene pigment, the adhesive force with a base material is not considered in the coating of the inner layer of the patent, the multilayer structure design leads to complex spraying preparation and coating steps, the energy consumption cost is increased, the bonding degree between different interlayer structures is poor, stripping and falling easily occur between the coating layers, and the sense of a wearer are affected.

Before the helmet shell is sprayed, oil stains, hand sweat, a release agent and the like are commonly spread on the surface of the helmet shell, so that the coating film adhesive force of the sprayed coating can be influenced, and the three patents are designed for heat preservation and heat dissipation of the helmet, but do not consider the adhesive force of the coating and the helmet shell, and the risk that the coating is easy to fall exists.

Disclosure of Invention

The application aims to overcome the defects of the prior art, and provides a bi-component coating for a helmet and a preparation method thereof, so as to solve the technical problems that the existing helmet coating needs to be coated with three layers before being sprayed, the spraying process is complex, the adhesive force between the coating and the helmet is poor, and the helmet is easy to fall off.

In order to achieve the above object, according to a first aspect of the present application, there is provided a two-component coating for helmets, comprising a first component and a second component; the component A comprises the following components in parts by mass:

100 parts of hydroxyl acrylic resin, 8-35 parts of polyol resin, 2-12 parts of adhesion promoter, 15-45 parts of organic cold pigment and 40-120 parts of first diluent, wherein the organic cold pigment is at least one of benzimidazolone pigment and phthalocyanine pigment;

the component B comprises the following components:

100 parts of isocyanate curing agent and 40-100 parts of second diluent.

Further, the organic cold pigment is a coupling agent modified pigment, and the modification process is as follows:

adding the benzimidazolone pigment or the phthalocyanine pigment into a third diluent, and performing ultrasonic dispersion for 0.5-2 h at the temperature of 30-50 ℃;

then adding a coupling agent, and carrying out ultrasonic treatment for 1-3 h at 50-60 ℃; the coupling agent is any one of titanate coupling agent, aluminate coupling agent, fluorosilane modified coupling agent, zirconate coupling agent, aluminum-zirconate coupling agent and aluminum-titanium composite coupling agent.

Further, the coupling agent is added in an amount of 0.1 to 10% by mass of the benzimidazolone-based pigment or the phthalocyanine-based pigment.

Further, the polyol resin is at least one of polyester polyol, polycaprolactone polyol and polyether polyol.

Further, the adhesion promoter is at least one of a modified chlorinated polyolefin or a rosin resin.

Further, the benzimidazolone pigment is at least one of benzimidazolone H3R, benzimidazolone HG, benzimidazolone brown HFR and benzimidazolone reddish brown HFM; and/or

The phthalocyanine pigment is phthalocyanine blue.

Further, each of the first diluent and the second diluent is independently one or a mixture of more than two of the following: aromatic hydrocarbon of C7-C10, ester compound of C3-C8, alcohol compound of C1-C5, ketone compound of C2-C6.

Further, the component A also comprises an auxiliary agent, wherein the auxiliary agent comprises at least one of an inorganic filler, a catalyst, a wetting dispersant, a leveling agent, a defoaming agent and an ultraviolet auxiliary agent.

In a second aspect of the present application, there is provided a method of preparing a two-component coating for a helmet, comprising the steps of:

preparing a component A: taking all raw materials of the component A according to the mass ratio, sequentially adding hydroxyl acrylic resin, polyol resin, adhesion promoter and organic cold pigment into a first diluent under stirring, pre-dispersing, grinding until the particle fineness is less than or equal to 5 microns, and filtering;

preparing a component B: uniformly mixing an isocyanate curing agent and a second diluent according to a mass ratio, and filtering;

and the component A and the component B are respectively stored after being prepared, and are mixed according to a proportion when in use, so that the bi-component coating for the helmet is obtained.

Further, when in use, the component A and the component B are used according to the mass ratio of isocyanate groups in the component B to hydroxyl groups in the component A of 0.6 to 1.5: 1.0.

Compared with the prior art, the application has the following technical effects:

according to the bi-component coating for the helmet, the organic cold pigment is introduced into the formula, so that the infrared reflectivity of the coating is effectively improved, the infrared heat absorption capacity of the coating is greatly reduced, meanwhile, the coating and the helmet base material have good adhesion performance and good fusion with the finish paint by matching with the polyol resin and the adhesion promoter, and the coating is not easy to fall off after spraying.

The bi-component coating for the helmet has good adhesive force with the helmet base material, can replace the primer coating and the middle coating in the original process, combines the primer coating and the middle coating into one, simplifies the production process, is more environment-friendly, solves the complex problem of the prior process, has simple construction and low cost, can realize industrial production, and is favorable for popularization and application.

The preparation method of the bi-component coating for the helmet is simple, the preparation conditions are stable and controllable, and the large-scale production is easy to realize.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In the present application, the term "and/or" describes an association relationship of an association object, which means that three relationships may exist, for example, a and/or B may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

It should be understood that, in various embodiments of the present application, the sequence number of each process described above does not mean that the execution sequence of some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weights of the relevant components mentioned in the description of the embodiments of the present application may refer not only to the specific contents of the components, but also to the proportional relationship between the weights of the components, so long as the contents of the relevant components in the description of the embodiments of the present application are scaled up or down within the scope of the disclosure of the embodiments of the present application. Specifically, the mass described in the specification of the embodiment of the application can be mass units known in the chemical industry field such as mu g, mg, g, kg.

The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated for distinguishing between objects such as substances from each other. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In a first aspect, embodiments of the present application provide a two-component coating for a helmet, comprising a first component and a second component; the component A comprises the following components in parts by weight:

100 parts of hydroxyl acrylic resin, 8-35 parts of polyol resin, 2-12 parts of adhesion promoter, 15-45 parts of organic cold pigment, 40-120 parts of first diluent, and at least one of benzimidazolone pigment and phthalocyanine pigment;

the component B comprises the following components:

100 parts of isocyanate curing agent and 40-100 parts of second diluent.

In the component A of the embodiment of the application, the hydroxy acrylic resin is matrix resin with more polar groups, can increase the adhesive force with a plastic substrate, and has good matching property with common finish paint. Preferably, the hydroxyl acrylic resin has a solid content of 20% -70%, a hydroxyl value of 25-120 mg KOH/g, an acid value of less than or equal to 10.0mg KOH/g and a viscosity of 1000-5000cps/25 ℃.

The polyol resin is one or more than two of polyester polyol, polycaprolactone polyol and polyether polyol. The polyol resin contains a longer flexible chain structure, the shrinkage of the coating film is small, and meanwhile, the coating film and the substrate form hydrogen bonds to contribute to the adhesion of the coating. The polyol resin is preferably an ester-group-containing polycaprolactone polyol or polyether polyol, the acid value of the polyol is less than or equal to 10.0mg KOH/g, the hydroxyl content is 1.0-5.0%, the water content is less than or equal to 0.1%, and the hydroxyl content and the water content are all mass percent. The polyol resin in the embodiment of the application is polyester polyol DESMOPHEN1652, polyester polyol DESMOPHEN1150 or PasteCapa 3031 polycaprolactone polyol produced by Germany Bayer company, and Dow CASE polyether polyol 3003LM.

The adhesion promoter is a low molecular compound such as modified chlorinated polyolefin or rosin resin, and is generally a high molecular solution without silicone, and can form a molecular bridge between the coating film and the substrate through chemical reaction or physical action to adhere the two together.

The organic cold pigment is reflective in the infrared region, meaning that less solar energy is absorbed, i.e., less heat is absorbed, and can effectively reduce the heat absorption at the helmet surface. The organic cold pigment of the embodiment of the application is one or two of benzimidazolone pigments and phthalocyanine pigments. Benzimidazolone-based pigments include, but are not limited to, one or more of benzimidazolone H3R, benzimidazolone HG, benzimidazolone brown HFR, benzimidazolone red brown HFM. The phthalocyanine-based pigment is a pigment having a phthalocyanine skeleton, and includes a phthalocyanine coordinated with various metals. The examples of the present application use amorphous phthalocyanine pigments and blue pigments such as phthalocyanine blue. The particle size of the organic cold pigment used in the embodiment of the application is 0.01-0.20 microns.

Further, the organic cold pigment of the embodiment of the application is a coupling agent modified pigment, and the modification process is as follows:

adding benzimidazolone pigment or the phthalocyanine pigment into a third diluent, and performing ultrasonic dispersion for 0.5-2 h at 30-50 ℃; the mass ratio of the benzimidazolone pigment or the phthalocyanine pigment to the third diluent is selected as 100: (20-60);

The coupling agent improves the surface polarity of the organic cold pigment, improves the compatibility of the organic cold pigment and matrix resin, reduces the particle agglomeration phenomenon, improves the performances of the pigment in the aspects of wettability, dispersibility and the like, more effectively plays a radiation refrigeration effect, further enhances the adhesive force between the paint and a helmet base material, and ensures that the sprayed coating is less prone to falling off, so that the helmet is more weather-resistant.

In the embodiment of the application, the addition amount of the coupling agent is 0.1-10% of the mass of the benzimidazolone pigment or the phthalocyanine pigment. Preferably 0.3% -5%, if the addition amount is less than 0.1%, the organic cold pigment cannot be completely treated, the fusion of the organic cold pigment and the matrix resin is affected, and if the addition amount is more than 10%, the residual functional coupling agent migrates to the surface, the adhesion of the coating and the substrate is affected, and the infrared reflection of the organic cold pigment is weakened.

In the component B, the isocyanate curing agent is non-yellowing, gloss-retaining and chalking-resistant aliphatic isocyanate, preferably one or a mixture of more than two of isophorone diisocyanate (IPDI) trimer, hexamethylene Diisocyanate (HDI) biuret and Hexamethylene Diisocyanate (HDI) trimer.

In the component A and the component B of the embodiment of the application, the first diluent and the second diluent can reduce the surface tension of the coating, adjust the viscosity of the coating and the application and storage time, generate a certain degree of swelling effect on the surface of the substrate, do not damage the smoothness of the surface of the substrate, and improve the adhesive force and the final coating performance. The first diluent, the second diluent and the third diluent are respectively and independently one or more than two of the following: aromatic hydrocarbon of C7-C10, ester compound of C3-C8, alcohol compound of C1-C5, ketone compound of C2-C6.

Further, each of the first diluent, the second diluent and the third diluent is independently one or a mixture of more than two of the following: toluene, xylene, n-butyl acetate, propylene methyl ether acetate, methyl formate, butyl formate, methyl glycol, methanol, n-butanol, butanone, ketone, cyclohexanone; the specific components can be used in a matching way according to the performance and practical application condition of the paint, and more preferably one or more than two of the following components are mixed: toluene, xylene, methyl formate, butyl formate, propylene glycol methyl ether acetate, and butanone.

In order to enable the obtained coating to have a certain covering power on the substrate, the component A of the two-component coating can further comprise an auxiliary agent, wherein the auxiliary agent comprises at least one of an inorganic filler, a catalyst, a wetting dispersing agent, a leveling agent, a defoaming agent and an ultraviolet auxiliary agent.

The inorganic filler of the embodiment of the application is preferably one or a mixture of more than two of rutile type titanium dioxide, chromia black, nickel titanate yellow, iron oxide red, iron oxide yellow or ultramarine. Further, it is preferably one or a mixture of two or more of titanium white, carbon black, iron oxide red, iron oxide yellow and ultramarine. The particle size of the inorganic filler is 1-15 mu m.

In addition, a catalyst can be added to improve the reaction rate of the polyisocyanate at room temperature; in order to enhance the lyophilicity of the pigment, improve the mechanical milling efficiency and prevent flooding, a wetting dispersant can be added; to obtain a smooth, even coating film, a leveling agent can be added; to suppress or eliminate bubbles generated during the coating process, an antifoaming agent may be added.

The catalyst may be one or a mixture of more than two of a tertiary amine catalyst, a metal compound catalyst, a preferred catalyst being a metal compound catalyst particularly suitable for increasing the reaction rate of aliphatic isocyanates, most preferably zinc isooctanoate or dibutyltin dilaurate.

The wetting dispersant is generally a copolymer containing acidic groups or a high molecular weight block copolymer solution with pigment affinic groups, preferably BYK-163 or BYK-9010 manufactured by the German Bick chemical Co.

The leveling agent is preferably polyester or polyether modified polydimethylsiloxane polymer, and can reduce the surface tension of the paint, increase the wettability of the paint to a substrate and greatly improve the adhesive force of the paint on the surface of plastic products. BYK-371 manufactured by Bick chemical Co., ltd. Germany is preferred.

The defoaming agent is an organosilicon defoaming agent, the consumption of the defoaming agent or the type of the defoaming agent is selected improperly, so that defects such as shrinkage cavity, shrinkage edge, pinholes and the like of a coating film can be caused, and the water resistance and the adhesive force of the coating film can be reduced, so that attention is paid to selecting the type and the addition amount of the defoaming agent. Silicone based defoamers such as polydimethylsiloxane are preferred.

The ultraviolet auxiliary agent comprises an ultraviolet absorber and a hindered amine light stabilizer; the ultraviolet absorbent is benzophenone and/or benzotriazole.

In a second aspect of the embodiments of the present application, there is provided a method for preparing a two-component coating for a helmet, comprising the steps of:

(1) Preparing a component A: taking all raw materials of the component A according to the mass ratio, sequentially adding hydroxyl acrylic resin, polyol resin, adhesion promoter and organic cold pigment into a first diluent under stirring, pre-dispersing, grinding until the particle fineness is less than or equal to 5 microns, and filtering; if necessary, an auxiliary agent can be added into the component A;

(2) Preparing a component B: uniformly mixing an isocyanate curing agent and a second diluent according to a mass ratio, and filtering;

(3) The component A and the component B are respectively stored after being prepared, and are mixed according to a proportion when in use, thus obtaining the bi-component coating for the helmet. Further, when in use, the mass ratio of the isocyanate groups in the component A to the hydroxyl groups in the component B is 0.6 to 1.5: 1.0. Preferably 0.8 to 1.2:1.0 Mixing, more preferably 1.0 to 1.2:1, most preferably at 1.0: 1.0. The component A and the component B are proportioned and mechanically mixed uniformly to prepare the mixed coating, the mixed coating can be directly sprayed on the helmet shell, and the helmet shell is prepared by baking at 50-80 ℃ for 30-120 min. The thickness of the coating is generally from 10 to 50. Mu.m.

The amount of the substance of hydroxyl group (OH) in the A component can be calculated from the hydroxyl value in the hydroxyacrylic acid contained in the A component. The hydroxyl number of the hydroxy acrylic resin is typically directly identified on the commodity package or may be self-detected.

The amount of the isocyanate group (NCO) substance in the b component can be calculated from the NCO content (mass percent) in the isocyanate curing agent contained in the b component. The NCO value in the isocyanate curing agent is also a commodity identification parameter or can be detected by self.

Materials of the helmet shell include but are not limited to ABS, ABS\PC, PP and glass fiber rigid body; in the injection molding process of the helmet base material, oil stains such as a release agent and a guide rail oil are adhered to the surface of a workpiece due to the use of the release agent, so that the problems of oil points, oil spots, pinholes, craters and the like appear on the surface after spraying, and the quality is greatly influenced, so that wiping is performed before coating. The helmet shell is easy to form internal stress in the forming process, and the coating is cracked due to the action of the stress after spraying, so that the helmet shell is annealed, and the internal stress of the helmet shell is released conveniently. The annealing mode is that the annealing is carried out for 120-60min under the temperature of 60-12 ℃. The helmet shell is easy to generate static electricity, fine dust and the like in the air can be adsorbed on the surface of a plastic product, and the static electricity is difficult to clean by using conventional blowing treatment, so that the static electricity is removed by high-pressure plasma airflow, and dust removal treatment is carried out.

The following examples illustrate a two-component coating for helmets and a method of making the same according to embodiments of the present application.

Example 1

The embodiment 1 of the application provides a bi-component coating for a helmet and a preparation method thereof, and the bi-component coating comprises the following steps:

100g of butanone is placed in a container in parts by mass, 100g of hydroxy acrylic resin MR7323E (the hydroxyl value is 33mg KOH/g), 8g of polyester polyol DESMOPHEN1652,2g of adhesion promoter ADK,15g of benzimidazolone H3R,0.01g of catalyst zinc isooctanoate, 0.69g of wetting dispersant BYK-163, 24g of rutile type titanium dioxide and 1g of carbon black are sequentially added under low-speed stirring, 1g of carbon black is pre-dispersed, then grinding is carried out by a sand mill until the particle fineness is less than or equal to 5 microns, 0.3g of flatting agent BYK310 is added, after uniform mixing, viscosity is adjusted, and filtering is carried out, thus obtaining the A component pigment slurry; 50g of isophorone diisocyanate (IPDI) trimer (NCO content 37.5%) was uniformly mixed with 20g of xylene and 30g of butyl formate, and filtered to obtain a second component;

the molar ratio of the component A to the component B is 1.2:1.0, spraying the mixture on an ABS helmet shell in a spraying manner, wherein the spraying amount is 100g/m ² Drying and leveling for 8min at 25 ℃ and curing and drying for 50min at 70 ℃ under the spraying pressure of 0.35 MPa.

Example 2

The embodiment 2 of the application provides a bi-component coating for a helmet and a preparation method thereof, and the bi-component coating comprises the following steps:

placing 50g of dimethylbenzene in a container, sequentially adding 100g of hydroxy acrylic resin RS-5605 (with a hydroxyl value of 100mg KOH/g), 30g of polycaprolactone polyol Capa3031, 10g of adhesion promoter ADK,40g of benzimidazolone H3R,0.1g of catalyst dibutyltin dilaurate, 1.68g of wetting dispersant BYK-163, 25g of titanium dioxide and 3g of nano silicon dioxide under low-speed stirring, grinding by a sand mill until the particle fineness is less than or equal to 5 microns, adding 0.1g of flatting agent BYK310, uniformly mixing, adjusting the viscosity, and filtering to obtain a first component pigment slurry; 60g of Hexamethylene Diisocyanate (HDI) trimer (NCO content 19.6%) and 50g of toluene were uniformly mixed and filtered to obtain a component B;

the molar ratio of the component A to the component B is 1.0:1.0, spraying the mixture on an ABS helmet shell in a spraying manner, wherein the spraying amount is 100g/m ² Drying and leveling for 8min at 25 ℃ and curing and drying for 50min at 70 ℃ under the spraying pressure of 0.35 MPa.

Example 3

The embodiment 3 of the application provides a bi-component coating for a helmet and a preparation method thereof, and the bi-component coating comprises the following steps:

placing 50g of propylene glycol methyl ether acetate in a container, sequentially adding 100g of hydroxy acrylic resin MR7323E (hydroxyl value is 33mg KOH/g), 15g of polyether polyol 3003LM,8g of adhesion promoter ADK,35g of phthalocyanine blue, 0.1g of catalyst zinc iso-octoate, 1.6g of wetting dispersant BYK-163, 15g of titanium dioxide and 5g of carbon black under low-speed stirring, pre-dispersing, grinding by a sand mill until the particle fineness is less than or equal to 5 microns, adding 0.1g of flatting agent BYK310, uniformly mixing, adjusting viscosity, and filtering to obtain a component A pigment slurry; 50g of Hexamethylene Diisocyanate (HDI) biuret (NCO content 16.5%) and 50g of butyl formate were uniformly mixed and filtered to obtain a component B;

the molar ratio of the component A to the component B is 1.0:1.0, and spraying the mixture on AB in a spraying modeOn the S-material helmet shell, the paint spraying amount is 100g/m ² Drying and leveling for 8min at 25 ℃ and curing and drying for 50min at 70 ℃ under the spraying pressure of 0.35 MPa.

Example 4

The difference from example 1 is that the coupling agent modified benzimidazolone H3R is added into the component A, and the modification process is as follows: 100g of benzimidazolone H3R is added into 60g of butanone, and the mixture is subjected to ultrasonic dispersion for 1H at 40 ℃; then, 0.3g of titanate coupling agent is added, ultrasonic treatment is carried out for 2 hours at 50 ℃, and the modified benzimidazolone H3R is obtained after filtration and drying. Other procedures were the same as in example 1.

Example 5

The difference from example 3 is that the coupling agent is added to the component A to modify the phthalocyanine blue, the modification process is as follows: 100g of phthalocyanine blue is added into 50g of propylene glycol methyl ether acetate, and the mixture is subjected to ultrasonic dispersion for 1h at 40 ℃; then, 0.5g of fluorosilane modified coupling agent is added, ultrasonic treatment is carried out for 2 hours at 50 ℃, and modified phthalocyanine blue is obtained after filtration and drying. Other procedures were the same as in example 3.

Comparative example 1

This differs from example 1 in that the polyester polyol desmoplen 1652 was not added to the a component, and the other processes were the same as in example 1.

Comparative example 2

This differs from example 1 in that the polyester polyol DESMOPHEN1652 and the adhesion promoter ADK were not added to the a component, and the other processes were the same as in example 1.

Comparative example 3

This differs from example 3 in that the polyether polyol 3003LM was not added to the a component, and the other process was the same as in example 3.

Comparative example 4

This differs from example 4 in that no modified benzimidazolone H3R was added to the A component, and the other procedures were the same as in example 4.

Comparative example 5

This differs from example 5 in that modified phthalocyanine blue is not added to the A component, and the other processes are the same as in example 5.

The adhesive force test evaluation was performed on the helmet shells sprayed according to the present application of examples 1 to 5, comparative examples 1 to 3, and the evaluation criteria were performed according to ISO-2409-2007, and the test results are shown in table 1 below.

TABLE 1

As can be seen from table 1 above, the coatings prepared in examples 1-5 of the present application all have good adhesion to the helmet shell; compared with the examples 1 and 3, the examples 4 and 5 show that the adhesive force between the coating system and the helmet shell can be further improved by adding the organic cold pigment modified by the coupling agent into the component A of the coating, and the coating is less prone to falling off; comparative examples 1-3 demonstrate that the addition of a polyol resin and an adhesion promoter to a coating system helps to enhance the adhesion between the coating and the helmet shell.

The coating films formed after the coating materials prepared in the application examples 1 to 5 and the coating materials prepared in the comparative examples 4 to 5 were subjected to infrared reflectance test by the following methods: the film was placed in a Perkin Elmer, lambda 950 type UV/Vis/NIR Spectrometer (ultraviolet/visible/near infrared spectrophotometer) to measure the reflectance of the film in the wavelength range of 400 to 2500nm with a measurement interval of 1nm. The average value of the reflectivity of the film in the 400-2500 nm band is taken as the reflectivity R of the film. The test results are shown in table 2 below.

TABLE 2

From the above table 2, the coating film formed after the coating prepared in the examples 1-5 of the application is sprayed has the reflectivity of more than 70% to infrared light, and comparative examples 4 and 5 show that the reflectivity of the coating to infrared light can be obviously enhanced by adding the modified organic cold pigment into the coating system, so that the absorption of the helmet to infrared light is reduced, the temperature of the helmet is reduced, and the wearing comfort of the helmet is improved.

Claims

1. A two-component coating for helmets is characterized by comprising a component A and a component B; the component A comprises the following components in parts by mass:

100 parts of hydroxyl acrylic resin, 8-35 parts of polyol resin, 2-12 parts of adhesion promoter, 15-45 parts of organic cold pigment and 40-120 parts of first diluent, wherein the polyol resin is at least one of polyester polyol and polyether polyol; the adhesion promoter is at least one of modified chlorinated polyolefin or rosin resin; the organic cold pigment is at least one of benzimidazolone pigment and phthalocyanine pigment; the benzimidazolone pigment is at least one of benzimidazolone H3R, benzimidazolone HG, benzimidazolone brown HFR and benzimidazolone reddish brown HFM; and/or

The phthalocyanine pigment is phthalocyanine blue;

the component B comprises the following components:

100 parts of isocyanate curing agent and 40-100 parts of second diluent;

the organic cold pigment is a coupling agent modified pigment, and the modification process is as follows:

adding the benzimidazolone pigment or the phthalocyanine pigment into a third diluent, and performing ultrasonic dispersion at 30-50 ℃ for 0.5-2 h;

then adding a coupling agent, and carrying out ultrasonic treatment at 50-60 ℃ for 1-3 h; the coupling agent is any one of titanate coupling agent, aluminate coupling agent, fluorosilane modified coupling agent, zirconate coupling agent, aluminum-zirconate coupling agent and aluminum-titanium composite coupling agent.

2. The two-component paint for helmets according to claim 1, wherein the coupling agent is added in an amount of 0.1 to 10% by mass of the benzimidazolone-based pigment or the phthalocyanine-based pigment.

3. A two-component coating for helmets according to claim 1, wherein the polyester polyol is a polycaprolactone polyol.

4. A two-component coating for helmets according to claim 1, wherein each of said first diluent, said second diluent and said third diluent is independently one or a mixture of two or more of the following: aromatic hydrocarbon of C7-C10, ester compound of C3-C8, alcohol compound of C1-C5, ketone compound of C2-C6.

5. A two-component coating for helmets according to any one of claims 1 to 4, wherein the component a further comprises an auxiliary agent comprising at least one of an inorganic filler, a catalyst, a wetting dispersant, a leveling agent, an antifoaming agent, and an ultraviolet auxiliary agent.

6. A method of preparing a two-component coating for helmets according to any one of claims 1 to 5, comprising the steps of:

and the component A and the component B are respectively stored after being prepared, and are mixed according to a proportion when in use, so that the double-component coating for the helmet is obtained.

7. The method for preparing a two-component coating for helmets according to claim 6, wherein the ratio of the amounts of the isocyanate groups in the component a and the hydroxyl groups in the component b is 0.6 to 1.5: 1.0.