Ultrahigh-film-thickness two-component polyurethane yellow finish paint and application thereof

Abstract

The invention provides two-component polyurethane yellow finish paint with ultrahigh film thickness and application thereof, and belongs to the technical field of paint. The two-component polyurethane yellow finish paint comprises a main agent and a curing agent which are independently subpackaged, and the main agent comprises the following components in percentage by mass: 30-50% of PA-3332 waterborne polyurethane resin, 1-2% of a dispersing agent, 5-15% of precipitated barium sulfate, 20-40% of covering yellow, 5-15% of rutile titanium dioxide, 3-20% of water, 0.2-0.5% of a thickening agent, 0.2-1% of a wetting defoaming agent, 0.1-1% of a wetting agent and 5-8% of a cosolvent; the curing agent comprises the following components in percentage by mass: 60-90% of a 3900 curing agent and 10-40% of propylene glycol methyl ether acetate. The yellow paint prepared by matching the PA-3332 waterborne polyurethane resin with the 3900 isocyanate curing agent can achieve the effect that a dry film does not generate prickly heat bubbles within 180 microns.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a two-component polyurethane yellow topcoat with ultra-high film thickness and application thereof. Background Art

[0002] In rail transit coatings, the existing polyurethane topcoat has a blister film thickness of 60 to 80 μm, and some as high as around 110 μm. The covering power of some bright yellow topcoats is not very good, and spraying is often thick, especially at the junction of spraying, the dry film thickness may be 160 μm, so it is easy to form blisters in this place, so these blisters need to be polished clean, which is a lot of work. If the polishing does not reach the middle coating, there will be pinholes, which brings a lot of trouble to the workers. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a two-component polyurethane yellow topcoat with ultra-high film thickness and its application. The two-component polyurethane yellow topcoat of the present invention can achieve a bubble-free film thickness of 180 μm.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a two-component polyurethane yellow topcoat with ultra-high film thickness, comprising a main agent and a curing agent which are packaged separately.

[0006] The main agent includes the following components in mass percentage: 30-50% PA-3332 waterborne polyurethane resin, 1-2% dispersant, 5-15% precipitated barium sulfate, 20-40% covering yellow, 5-15% rutile titanium dioxide, 3-20% water, 0.2-0.5% thickener, 0.2-1% wetting defoamer, 0.1-1% wetting agent, and 5-8% cosolvent;

[0007] The curing agent comprises the following components in percentage by mass: 60-90% of 3900 curing agent and 10-40% of propylene glycol methyl ether acetate.

[0008] Preferably, the main agent includes the following components in mass percentage: 32% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 18.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

[0009] Preferably, the main agent includes the following components in mass percentage: 37% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 13.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

[0010] Preferably, the main agent includes the following components in mass percentage: PA-3332 waterborne polyurethane resin 42%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 8.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, and cosolvent 5%.

[0011] Preferably, the main agent includes the following components in mass percentage: PA-3332 waterborne polyurethane resin 47%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 3.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, and cosolvent 5%.

[0012] Preferably, the mass ratio of the main agent to the curing agent is 3:1.

[0013] Preferably, the thickness of the two-component polyurethane yellow topcoat is 140-180 μm.

[0014] Preferably, the thickness of the two-component polyurethane yellow topcoat is 150-160 μm.

[0015] Preferably, the curing agent comprises the following components in percentage by mass: 85% of 3900 curing agent and 15% of propylene glycol methyl ether acetate.

[0016] The present invention also provides the use of the ultra-high film thickness two-component polyurethane yellow topcoat described in the above technical solution in the field of rail transportation.

[0017] The invention provides a two-component polyurethane yellow topcoat with ultra-high film thickness, comprising a main agent and a curing agent which are independently packaged, wherein the main agent comprises the following components in mass percentage: 30-50% of PA-3332 waterborne polyurethane resin, 1-2% of dispersant, 5-15% of precipitated barium sulfate, 20-40% of covering yellow, 5-15% of rutile titanium dioxide, 3-20% of water, 0.2-0.5% of thickener, 0.2-1% of wetting defoamer, 0.1-1% of wetting agent and 5-8% of cosolvent; and the curing agent comprises the following components in mass percentage: 60-90% of 3900 curing agent and 10-40% of propylene glycol methyl ether acetate.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The yellow paint made of PA-3332 waterborne polyurethane resin and 3900 isocyanate curing agent can achieve a dry film thickness of less than 180 μm without causing prickly heat blisters. DETAILED DESCRIPTION

[0020] The present invention provides a two-component polyurethane yellow topcoat with ultra-high film thickness, comprising a main agent and a curing agent which are packaged separately.

[0021] The main agent includes the following components in mass percentage: 30-50% PA-3332 waterborne polyurethane resin, 1-2% dispersant, 5-15% precipitated barium sulfate, 20-40% covering yellow, 5-15% rutile titanium dioxide, 3-20% water, 0.2-0.5% thickener, 0.2-1% wetting defoamer, 0.1-1% wetting agent, and 5-8% cosolvent;

[0022] The curing agent comprises the following components in percentage by mass: 60-90% of 3900 curing agent and 10-40% of propylene glycol methyl ether acetate.

[0023] In the present invention, unless otherwise specified, the raw materials used are all commercially available products in the art.

[0024] In the present invention, the main agent preferably includes the following components in mass percentage:

[0025] PA-3332 waterborne polyurethane resin 32%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 18.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, cosolvent 5%;

[0026] Or including the following components in percentage by mass: PA-3332 waterborne polyurethane resin 37%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 13.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, cosolvent 5%;

[0027] Or including the following components in percentage by mass: PA-3332 waterborne polyurethane resin 42%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 8.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, cosolvent 5%;

[0028] Or including the following components in percentage by mass: PA-3332 waterborne polyurethane resin 47%, dispersant 2%, precipitated barium sulfate 8%, covering yellow 25%, rutile titanium dioxide 8%, water 3.7%, thickener 0.3%, wetting defoamer 0.8%, wetting agent 0.2%, and cosolvent 5%.

[0029] In the present invention, the PA-3332 waterborne polyurethane resin is preferably purchased from Guangzhou Guanzhi New Material Technology Co., Ltd.

[0030] In the present invention, the dispersant is preferably 6208 dispersant (U.S. Allnex dispersant VXW6208).

[0031] In the present invention, the thickener is preferably thickener WT-102.

[0032] In the present invention, the wetting agent is preferably wetting agent 4100.

[0033] In the present invention, the wetting and defoaming agent is preferably 104E wetting and defoaming agent.

[0034] In the present invention, the water is preferably deionized water.

[0035] In the present invention, the cosolvent is preferably dipropylene glycol butyl ether (DPNB).

[0036] In the present invention, the mass ratio of the main agent to the curing agent is preferably 3:1.

[0037] In the present invention, the thickness of the two-component polyurethane yellow topcoat is preferably 140-180 μm, more preferably 150-160 μm, specifically 140, 150, 160, 170 or 180 μm.

[0038] In the present invention, the curing agent preferably includes the following components in mass percentage: 85% 3900 curing agent, 15% propylene glycol methyl ether acetate (PMA)

[0039] In the present invention, the 3900 curing agent is preferably Covestro Desmodur N3900 HDI-based curing agent.

[0040] The present invention has no special limitation on the preparation method of the ultra-high film thickness two-component polyurethane yellow topcoat, and it can be prepared by a preparation method of a composition well known to those skilled in the art.

[0041] In the present invention, the preparation method of the main agent preferably comprises pre-mixing, grinding and blending performed in sequence.

[0042] In the present invention, part of water, part of wetting defoamer, dispersant, rutile titanium dioxide, covering yellow and precipitated barium sulfate are preferably mixed for pre-refining to obtain pre-refined material.

[0043] In a specific embodiment of the present invention, it is preferred to first add the portion of water, start stirring, and the dispersion frequency is 200 to 500 rpm, then add the portion of wetting defoamer, stir for 2 to 3 minutes, and then add the dispersant, rutile titanium dioxide, covering yellow and precipitated barium sulfate in sequence, stirring for 3 to 5 minutes after each addition before adding the next item, and increase the stirring speed to 300 to 700 rpm. After adding, continue stirring for 15 minutes to complete the pre-refining.

[0044] After obtaining the pre-mixed material, the pre-mixed material is ground, and then flushed with the remaining water to obtain a grinding slurry.

[0045] The present invention has no particular limitation on the ratio of the partial water to the remaining water, and any ratio may be used.

[0046] In the present invention, the particle size of the polishing slurry is preferably ≤15 μm, more preferably ≤10 μm.

[0047] In the present invention, the grinding is preferably carried out in a sand mill, and the cooling water and slurry flow rates are adjusted so that the grinding temperature is preferably <50°C, the grinding pressure is preferably <0.2MPa, and monitoring and recording are preferably performed every 20 minutes; the grinding is carried out in an inverted cylinder, and the fineness is self-checked and recorded each time. After grinding to less than 15μm, samples are taken for inspection. If the fineness is qualified, the obtained pre-refined slurry is poured into a blending cylinder and ground with the remaining water to obtain a grinding slurry.

[0048] After obtaining the grinding slurry, the present invention mixes the grinding slurry, PA-3332 waterborne polyurethane resin, a wetting agent, a residual wetting defoaming agent, a thickener and a cosolvent to obtain the main agent.

[0049] The present invention has no particular limitation on the ratio of the partial wetting defoamer to the remaining wetting defoamer, and any ratio may be used.

[0050] In a specific embodiment of the present invention, the PA-3332 waterborne polyurethane resin and the wetting agent are preferably added to a mixing cylinder containing a grinding slurry, dispersed at a speed of 300 to 700 rpm for 5 minutes, and then the remaining wetting and defoaming agent is added, the stirring speed is increased to 500 to 900 rpm, stirred for 60 to 90 minutes, the stirring speed is adjusted to 300 to 700 rpm, and then the thickener and the cosolvent are added in turn, stirring for 3 to 5 minutes after each addition, and then adding the next item, and finally stirring for 20 minutes, and sampling for inspection.

[0051] The present invention also provides the use of the ultra-high film thickness two-component polyurethane yellow topcoat described in the above technical solution in the field of rail transportation.

[0052] The present invention has no particular limitation on the specific manner of the application, and any manner familiar to those skilled in the art may be used.

[0053] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Example 1

[0055] Preparation process of the main agent of ultra-high film thickness two-component polyurethane yellow topcoat:

[0056] First add the part of water, start stirring, the dispersion frequency is 500 rpm, then add the wetting defoamer, stir for 3 minutes, then add part of the wetting defoamer, dispersant, rutile titanium dioxide, covering yellow and precipitated barium sulfate in sequence, stir for 5 minutes after each addition, then add the next item, increase the stirring speed to 700 rpm, continue stirring for 15 minutes after adding, and complete the pre-refining; grind the obtained pre-refined material, pass it through a sand mill, adjust the cooling water and slurry flow rate, make the grinding temperature 40°C, the grinding pressure 0.15MPa, monitor and record every 20 minutes, grind in an inverted cylinder, self-check the fineness each time and record , grind to less than 15μm, take samples for inspection, if the fineness is qualified, put the obtained pre-refined slurry into the mixing cylinder, grind with the remaining water to obtain the grinding slurry; add PA-3332 water-based polyurethane resin and wetting agent into the mixing cylinder containing the grinding slurry, disperse at 700 rpm for 5 minutes, then add the remaining wetting defoamer, increase the stirring speed to 900 rpm, stir for 90 minutes, adjust the stirring speed at 700 rpm, and then add the thickener and co-solvent in turn, stir for 5 minutes after each addition, and finally stir for 20 minutes, take samples for inspection, and obtain the main agent of the ultra-high film thickness two-component polyurethane yellow topcoat.

[0057] The main agent formulas of Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Table 1. The resin in Examples 1 to 4 is PA-3332 waterborne polyurethane resin (purchased from Guangzhou Guanzhi New Material Technology Co., Ltd.), the resin in Comparative Example 1 is 2033 resin (purchased from Wanhua Chemical Group Co., Ltd.), and the resin in Comparative Example 2 is 2403 resin (purchased from United Curing Chemical Group).

[0058] The preparation processes of Examples 2 to 4 and Comparative Examples 1 to 2 are the same as those of Example 1, except that the types and amounts of raw materials are different.

[0059] Table 1 Main agent formula (wt%) of Examples 1 to 4 and Comparative Examples 1 to 2

[0060]

[0061]

[0062] The curing agent of the embodiment and the comparative example is the following components in mass percentage: 3900 curing agent (Covestro Desmodur N3900 HDI-based curing agent) 85%, PMA 15%

[0063] In the two-component polyurethane yellow topcoat of the embodiment and the comparative example, the mass ratio of the main agent to the curing agent is 3:1.

[0064] Performance Test:

[0065] The highest dry film thickness test without prickly heat blisters:

[0066] The maximum film thickness of the dry film of the non-prickly heat foam of Example 1 is 150 μm, the maximum film thickness of the dry film of the non-prickly heat foam of Example 2 is 180 μm, the maximum film thickness of the dry film of the non-prickly heat foam of Example 3 is 160 μm, the maximum film thickness of the dry film of the non-prickly heat foam of Example 4 is 160 μm, the maximum film thickness of the dry film of the non-prickly heat foam of Example 5 is 120 μm, and the maximum film thickness of the dry film of the non-prickly heat foam of Example 6 is 130 μm. It can be seen that the film thickness of the non-prickly heat foam of the experimental data of the embodiment is the highest.

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A two-component polyurethane yellow topcoat with ultra-high film thickness, characterized in that: Including independent packaging of main agent and curing agent, The main agent includes the following components in mass percentage: 30-50% PA-3332 waterborne polyurethane resin, 1-2% dispersant, 5-15% precipitated barium sulfate, 20-40% covering yellow, 5-15% rutile titanium dioxide, 3-20% water, 0.2-0.5% thickener, 0.2-1% wetting defoamer, 0.1-1% wetting agent, and 5-8% cosolvent; The curing agent comprises the following components in percentage by mass: 60-90% of 3900 curing agent and 10-40% of propylene glycol methyl ether acetate.

2. The two-component polyurethane yellow topcoat according to claim 1, characterized in that: The main agent includes the following components in percentage by mass: 32% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 18.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

3. The two-component polyurethane yellow topcoat according to claim 1, characterized in that: The main agent includes the following components in percentage by mass: 37% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 13.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

4. The two-component polyurethane yellow topcoat according to claim 1, characterized in that: The main agent includes the following components in percentage by mass: 42% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 8.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

5. The two-component polyurethane yellow topcoat according to claim 1, characterized in that: The main agent includes the following components in percentage by mass: 47% PA-3332 waterborne polyurethane resin, 2% dispersant, 8% precipitated barium sulfate, 25% covering yellow, 8% rutile titanium dioxide, 3.7% water, 0.3% thickener, 0.8% wetting defoamer, 0.2% wetting agent, and 5% cosolvent.

6. The two-component polyurethane yellow topcoat according to any one of claims 1 to 5, characterized in that: The mass ratio of the main agent to the curing agent is 3:

1.

7. The two-component polyurethane yellow topcoat according to any one of claims 1 to 5, characterized in that: The thickness of the two-component polyurethane yellow topcoat is 140-180 μm.

8. The two-component polyurethane yellow topcoat according to claim 7, characterized in that: The thickness of the two-component polyurethane yellow topcoat is 150-160 μm.

9. The two-component polyurethane yellow topcoat according to claim 1, characterized in that: The curing agent comprises the following components in percentage by mass: 85% of 3900 curing agent and 15% of propylene glycol methyl ether acetate.

10. Use of the ultra-high film thickness two-component polyurethane yellow topcoat according to any one of claims 1 to 9 in the field of rail transportation.

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