CN108977032B - Water-based dual-component high-gloss finish paint for helmet and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a water-based double-component high-gloss finish paint for a helmet and a preparation method thereof. The finish paint consists of paint and a cross-linking agent according to a weight ratio of 100 (16-19); the paint consists of a water-based hydroxy acrylic copolymer dispersoid, a leveling agent, a dispersant BYK-190, a pH value regulator, a film-forming auxiliary agent, conductive carbon black, a nonionic associative thickener, an alkali swelling thickener and deionized water; the cross-linking agent consists of hydrophobic HDI tripolymer, hydrophilic polyether modified aliphatic polyisocyanate based on HDI and propylene glycol monomethyl ether acetate. The finish paint provided by the invention has the characteristics of long working life, high hardness and good thixotropy, has the thickness of a wet film of more than 65 mu m without sagging and the defects of miliaria and hidden bubbles, and solves the technical problems of poor fullness and appearance of water-based paint caused by low solid content in construction.

Description

Water-based dual-component high-gloss finish paint for helmet and preparation method thereof

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a water-based double-component high-gloss finish paint for a helmet and a preparation method thereof.

Background

The composite material is a novel engineering material developed in recent decades, has the advantages of high specific strength, high specific stiffness and low relative density, and is particularly widely applied to the fields of motorcycle helmets, fire helmets and the like, such as ABS resin, glass fiber composite materials, carbon fiber composite materials and the like.

However, the composite material is subjected to the combined action of factors such as humid gas in the air, salt fog, rain, sunshine and the like in nature, so that the composite material generates an aging phenomenon, and the appearance and the mechanical property of the composite material are deteriorated. For example, unprotected ABS resin and glass fiber reinforced composites may undergo significant appearance changes under atmospheric conditions, surface tarnish, color change, cracking and peeling of the resin, or damage phenomena such as fiber bare oxidation. Therefore, in order to prolong the service life of composite material products such as helmets and the like, a paint film is required to be coated on the surface of the composite material products. Since the overall effect after coating is exhibited by the top-coat film, the top-coat film is required to have the characteristics of high gloss, good fullness, good medium resistance, excellent weather resistance, high hardness and strong adhesion.

Due to national environmental policy and increasingly stringent emission control of Volatile Organic Compounds (VOCs), solvent-based coatings have rapidly shifted to environmentally friendly waterborne coatings. The water-based finish paint used in many factories has the problems of slow drying, poor fullness and easy sagging during construction. But the drying speed is improved, and the defects of miliaria, dark bubbles and the like are easily generated when the water-based finish paint is baked; because the solid content of the water-based paint is generally 40-50% lower than that of a solvent-based paint in the construction process, the fullness is improved through the coating thickness, and the defect of sagging occurs; and the pot life of the two-component water-based paint is very sensitive to the thickening agent, and if the selection and the formula design of the thickening agent are not proper, the pot life is shortened rapidly after paint mixing, so that the workability is influenced. The high-grade helmet not only requires the coating to have good construction performance, but also requires the coating to have good appearance, decoration, comprehensive mechanical property, water resistance and aging resistance. At present, the existing two-component water-based finish paint can not meet the coating requirements, and serious sagging occurs when the thickness of one-time thick coating exceeds 45 mu m.

Disclosure of Invention

In order to solve the problems in the prior art (such as the defects of low drying speed, poor fullness, easy sagging during construction, easy prickly heat and hidden bubbles generation of a paint layer and the like) the invention provides the aqueous two-component high-gloss finish paint for the helmet, which has the characteristics of long service life, high hardness and good thixotropy, does not sag when the wet film is more than 65 mu m in thickness, does not have the defects of prickly heat and hidden bubbles, and solves the technical problem of poor fullness and appearance caused by low solid content during construction of the aqueous paint.

The invention provides a water-based double-component high-gloss finish paint for helmets, which is prepared from the following raw materials in parts by weight: painting, namely 100 (16-19) of a cross-linking agent;

the paint is prepared from the following raw materials in percentage by weight: 60-68% of water-based hydroxyl acrylic copolymer dispersoid, 0.1-0.2% of flatting agent, 0.0-2.0% of dispersing agent BYK-1901.5, 0.4-0.6% of pH value regulator, 1.5-2.0% of film-forming assistant, 4-5% of conductive carbon black, 0.2-0.3% of nonionic associative thickener, 3-5% of alkali swelling thickener and the balance of deionized water to 100%;

the cross-linking agent is prepared from the following raw materials in percentage by weight: 35-40% of hydrophobic HDI trimer, 45-50% of hydrophilic polyether modified aliphatic polyisocyanate based on HDI, and the balance of propylene glycol monomethyl ether acetate is 100%.

Preferably, the hydroxyl content of the aqueous hydroxy acrylic copolymer dispersoid is 3.8-4.2%, the solid content is 45-50%, and the particle size is less than or equal to 60 nm. The waterborne hydroxyl acrylic copolymer dispersion is Bayhydrol A XP2770 (the brand is Bayer, and the model is Bayhydrol A XP 2770).

Preferably, the leveling agent is Borchi Gen0451 (brand Borchers OM Group, model number Borchi Gen 0451).

Preferably, the pH modifier is AMP-95 (dow brand, model No. AMP-95), preferably, the coalescing agent is TEXANO L esterol (TEXANO model No. L), preferably, the nonionic associative thickener is TEGO3060 (dixano brand, model no 3060), preferably, the alkali swelling thickener is rheovisis AS1130 (basofv brand, model No. Rheovis AS1130), preferably, the hydrophobic HDI trimer is TPA-100 (asa brand, model No. TPA-100), preferably, the HDI-based hydrophilic polyether-modified aliphatic polyisocyanate is Bayhydur XP2547 (Bayhydur brand, model No. XP 2547).

The dispersant BYK-190 is named Bike and is of a model number BYK-190. The conductive carbon black is high-pigment conductive carbon black, the average particle size of the conductive carbon black is less than 30nm, and the conductive carbon black is VXC-72, the brand of which is Kabot and the model of which is VXC-72. Correspondingly, the invention also provides a preparation method of the waterborne two-component high-gloss finish paint for the helmet, which specifically comprises the following steps:

s1, putting deionized water, a dispersant BYK-190 and a pH value regulator into a dispersion cylinder according to the formula ratio, uniformly dispersing, slowly adding conductive carbon black, performing pre-dispersion for 20-30 min at the rotating speed of 300-500 rpm, and grinding the pre-dispersed mixture to be less than 8 microns by using a sand mill to obtain color paste;

s2, putting the aqueous hydroxyl acrylic copolymer dispersoid, the leveling agent and the film-forming assistant in the formula ratio into a paint preparation cylinder for uniform dispersion, then adding color paste, dispersing for 10-20 min at the rotating speed of 600-800 rpm, then adding the alkali swelling thickener and the nonionic associative thickener, dispersing for 5-10 min, and filtering to obtain a paint;

s3, taking the hydrophobic HDI tripolymer, the hydrophilic polyether modified aliphatic polyisocyanate based on HDI and propylene glycol monomethyl ether acetate according to the formula amount, mixing uniformly, and filtering to obtain the cross-linking agent;

and S4, adding the paint and the cross-linking agent into a dispersion cylinder in proportion, and dispersing for 3-5 min at the rotating speed of 200-300 rpm to obtain the water-based double-component high-gloss finish paint for the helmet.

The invention concept of the water-based double-component high-gloss finishing coat for the helmet is as follows: firstly, the invention adopts the higher solid content water-based hydroxyl acrylic copolymer dispersoid with the hydroxyl content of 3.8-4.2% and the particle size of less than or equal to 60nm as the base resin, can improve the drying speed, the glossiness and the fullness of the coating, and simultaneously, the obtained coating has the advantages of high hardness and good adhesive force with the base material.

Secondly, the non-ionic associative thickener and the alkali swelling thickener are compounded, and the alkali swelling thickener is mainly used for improving the viscosity of the paint; the strong pseudoplastic nonionic associative thickener is used as an auxiliary, so that the paint has high thixotropy, and the workability cannot be influenced by the sharp increase of the viscosity of the paint after the paint is prepared. Meanwhile, the conductive carbon black is used as a toning pigment, is favorable for the atomization uniformity of the coating by adopting an electrostatic spraying process, and can be used for one-time thick coating.

Furthermore, the hydrophobic HDI tripolymer and the hydrophilic polyether modified aliphatic polyisocyanate based on HDI are compounded to be used as a cross-linking agent, and the viscosity and the thixotropy of paint after paint preparation are improved by utilizing the faster reaction speed of the hydrophilic polyether modified aliphatic polyisocyanate based on HDI and the aqueous hydroxy acrylic copolymer dispersion, so that sagging during initial construction of paint preparation is avoided; but the viscosity and the thixotropy of the hydrophilic curing agent in the later period of paint preparation are reduced, and the viscosity and the thixotropy of the hydrophobic HDI trimer in the later period of paint preparation are synergistically improved. Therefore, the pot life of the coating formula system is longer than 5h, the coating has proper viscosity, thixotropy and good construction performance in the pot life after paint preparation, and the coating does not sag and has high surface drying speed even if the coating is constructed under the low-temperature and high-humidity environment conditions that the temperature is 5-15 ℃ and the humidity is higher than 95%.

Therefore, compared with the prior art, the invention has the following advantages:

(1) the VOC of the water-based double-component high-gloss finish paint for the helmet is less than 80 g/L, so that the water-based double-component high-gloss finish paint is more environment-friendly, has high construction solid content, moderate viscosity and good thixotropy, can be subjected to one-time thick coating by adopting electrostatic spraying and air spraying, has the wet film thickness of more than 65 mu m without sagging and the defects of miliaria and dark bubbles, and solves the technical problems of poor fullness and appearance of the water-based paint caused by low construction solid content.

(2) The water-based dual-component high-gloss finish paint for the helmet has the characteristics of long applicable period, high hardness and good thixotropy, can be thickly coated on the surface of a helmet and other complex shapes made of glass fiber reinforced plastics and ABS resin without sagging, has flat surface state of a paint film and high gloss and fullness, is suitable for air spraying and disc and rotary cup electrostatic production line coating processes, can not sag even if being constructed under the condition of low-temperature and high-humidity environment, has higher surface drying speed, and is simple and convenient to construct and low in cost.

(3) The water-based double-component high-gloss finishing coat for the helmet has good wetting, leveling and interlayer adhesion with a middle coat and a primer, can be directly coated on base materials such as ABS resin and the like, has excellent impact resistance, weather resistance and water resistance, can meet the good application on the helmet, and prolongs the service life of the helmet.

(4) The preparation method of the water-based dual-component high-gloss finish paint for the helmet is simple, stable in process, controllable in conditions, capable of realizing industrial production and beneficial to popularization and application.

Detailed Description

The present invention will be described in further detail with reference to specific examples. Examples, aqueous two-component high gloss topcoat for helmets of the invention and preparation thereof

As shown in table 1 below, a weight ratio table is presented for 6 examples of topcoats of the invention.

TABLE 1 topcoat formulations of inventive examples 1-6

The preparation method of examples 1 to 6 is as follows:

s1, putting deionized water, a dispersant BYK-190 and a pH value regulator into a dispersion cylinder according to the formula ratio, uniformly dispersing, slowly adding conductive carbon black, performing pre-dispersion for 25min at the rotating speed of 400rpm, and grinding the pre-dispersed mixture to be below 8 mu m by using a sand mill to obtain color paste;

s2, putting the aqueous hydroxyl acrylic copolymer dispersoid, the leveling agent and the film-forming assistant in the formula ratio into a paint preparation cylinder for uniform dispersion, then adding the color paste, dispersing for 20min at the rotating speed of 700rpm, then adding the alkali swelling thickener and the nonionic associative thickener, dispersing for 5min, and filtering to obtain a paint;

s3, taking the hydrophobic HDI tripolymer, the hydrophilic polyether modified aliphatic polyisocyanate based on HDI and propylene glycol monomethyl ether acetate according to the formula amount, mixing uniformly, and filtering to obtain the cross-linking agent;

s4, adding the paint and the cross-linking agent into a dispersion cylinder according to a proportion, and dispersing for 3min at the rotating speed of 300rpm to obtain the water-based two-component high-gloss finish paint for the helmet.

Test example I Performance testing of aqueous two-component high gloss topcoat for helmets in accordance with the invention

Examples 1-6 tests on the performance of the topcoat and the coatings thereof showed the results shown in Table 2 below.

Table 2 Performance test results of the topcoats of the examples

From table 2 above, it can be seen that:

(1) the water-based double-component high-gloss finish paint for the helmet has high construction solid content, proper viscosity and good thixotropy, the thickness of a wet film is more than 65 mu m, the water-based double-component high-gloss finish paint does not sag, does not have the defects of miliaria, hidden bubbles and the like, the working life reaches more than 5h, the water-based double-component high-gloss finish paint still has proper viscosity, thixotropy and good construction performance in the working life after paint preparation, and the water-based double-component high-gloss finish paint does not sag and has higher surface drying speed even if the water-based double-component high-gloss finish paint.

(2) The aqueous bi-component high-gloss paint film for the helmet has the advantages of flat and smooth surface state, high glossiness and fullness, high hardness, strong adhesive force, excellent impact resistance, weather resistance and water resistance, and can meet the good application on the helmet. In examples 1-6, the overall performance of the topcoat paint of example 5 is the best, so example 5 is the best embodiment of the invention.

Test example II, influence of different raw materials and proportions on the performance of the waterborne dual-component high-gloss finishing coat for the helmet

Comparative example 1: the comparative example differs from example 5 only in that: bayhydrol a 2470 was used as the starting material in place of Bayhydrol a XP 2770.

Comparative example 2: the comparative example differs from example 5 only in that: the raw material TEGO 3030 was used in place of TEGO 3060.

Comparative example 3: the comparative example differs from example 5 only in that: the dosage of Rheovis AS1130 was adjusted to 0.24kg and the dosage of TEGO3060 was adjusted to 4.0 kg.

Comparative example 4: the comparative example differs from example 5 only in that: TPA-100 was replaced with the feedstock Desmodur N3900.

Comparative example 5: the comparative example differs from example 5 only in that: bayhydur XP 254784 kg and propylene glycol methyl ether acetate 16kg were formulated as a cross-linker.

Comparative example 6: the comparative example differs from example 5 only in that: TPA-10048 kg, Bayhydur XP254736kg, and propylene glycol methyl ether acetate 16kg were formulated as a cross-linker.

The preparation methods of comparative examples 1 to 6 refer to the examples of the present invention, and the performances of the topcoats and coatings thereof of comparative examples 1 to 6 are tested by referring to the method of test example one, and the results are shown in table 3 below.

TABLE 3 Performance test results for various comparative topcoats

Item	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6
							Viscosity/s	45.9	31.7	27.9	38.7	38.3	31.9
Pot life/h	3	3.5	3	2.5	4	4.5
							Thixotropic index	1.65	2.30	2.58	1.69	2.15	2.27
Sagging/. mu.m	40	54	55	43	57	60
							Gloss 60 degree ∠	86.2	88.5	84.0	85.5	90.1	90.5
Hardness of pencil	HB	2H	H	HB	H	H
							Adhesion/grade	3	1	2	3	2	1

From table 3 above, it can be seen that: on the basis of the example 5 of the invention, the variety or the proportion of individual raw materials is changed, and the reduction of partial or even all performances is accompanied, so that the coating is a complex system, and the change of all factors can influence the performances of the coating. Therefore, the invention obtains the aqueous two-component high-gloss finishing coat for the helmet, which has excellent performance, particularly good thixotropy, long service life and a wet film thickness of more than 65 mu m, does not sag and does not have the defects of miliaria, dark bubbles and the like through the combination of specific raw materials.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims (7)

1. The water-based double-component high-gloss finish paint for the helmet is characterized by being prepared from the following raw materials in parts by weight: painting, namely 100 (16-19) of a cross-linking agent;

the paint is prepared from the following raw materials in percentage by weight: 60-68% of water-based hydroxyl acrylic copolymer dispersoid, 0.1-0.2% of flatting agent, 0.0-2.0% of dispersing agent BYK-1901.5, 0.4-0.6% of pH value regulator, 1.5-2.0% of film-forming assistant, 4-5% of conductive carbon black, 0.2-0.3% of nonionic associative thickener, 3-5% of alkali swelling thickener and the balance of deionized water to 100%;

the cross-linking agent is prepared from the following raw materials in percentage by weight: 35-40% of hydrophobic HDI trimer, 45-50% of hydrophilic polyether modified aliphatic polyisocyanate based on HDI and 100% of propylene glycol monomethyl ether acetate;

the hydroxyl content of the aqueous hydroxy acrylic copolymer dispersoid is 3.8-4.2%, the solid content is 45-50%, and the particle size is less than or equal to 60 nm; the nonionic associative thickener is TEGO 3060; the alkali swelling thickener is Rheovis AS 1130.

2. The waterborne two-component high gloss topcoat for helmets according to claim 1, wherein the leveling agent is Borchi Gen 0451.

3. The waterborne two-part high gloss topcoat for helmets according to claim 1, wherein the pH adjuster is AMP-95.

4. The waterborne two-part high gloss topcoat for helmets according to claim 1, wherein the coalescent is TEXANO L ester alcohol.

5. The waterborne two-part high gloss topcoat for helmets according to claim 1, wherein the hydrophobic HDI trimer is TPA-100.

6. The waterborne two-part high gloss topcoat for helmets according to claim 1, wherein the HDI-based hydrophilic polyether-modified aliphatic polyisocyanate is Bayhydur XP 2547.

7. The method for preparing the aqueous two-component high-gloss topcoat for helmets according to any one of claims 1 to 6, comprising the steps of:

s1, putting deionized water, a dispersant BYK-190 and a pH value regulator into a dispersion cylinder according to the formula ratio, uniformly dispersing, slowly adding conductive carbon black, performing pre-dispersion for 20-30 min at the rotating speed of 300-500 rpm, and grinding the pre-dispersed mixture to be less than 8 microns by using a sand mill to obtain color paste;

s2, putting the aqueous hydroxyl acrylic copolymer dispersoid, the leveling agent and the film-forming assistant in the formula ratio into a paint preparation cylinder for uniform dispersion, then adding color paste, dispersing for 10-20 min at the rotating speed of 600-800 rpm, then adding the alkali swelling thickener and the nonionic associative thickener, dispersing for 5-10 min, and filtering to obtain a paint;

s3, taking the hydrophobic HDI tripolymer, the hydrophilic polyether modified aliphatic polyisocyanate based on HDI and propylene glycol monomethyl ether acetate according to the formula amount, mixing uniformly, and filtering to obtain the cross-linking agent;

and S4, adding the paint and the cross-linking agent into a dispersion cylinder in proportion, and dispersing for 3-5 min at the rotating speed of 200-300 rpm to obtain the water-based double-component high-gloss finish paint for the helmet.