A kind of water-based amino baking varnish and its preparation method and application

Abstract

The present invention discloses a water-based amino baking varnish and a preparation method and application thereof. The water-based amino baking varnish of the present invention comprises the following components in percentage by mass: polyester resin: 25% to 35%; acrylic resin: 5% to 15%; film-forming aid: 10% to 15%; amino resin curing agent: 4% to 5%; adhesion promoter: 1.5% to 2%; wetting agent: 0.2% to 0.3%; defoamer: 0.1% to 0.3%; leveling agent: 0.5% to 1%; pH adjuster: 1% to 1.5%; water: balance. The preparation method of the water-based amino baking varnish of the present invention is very simple, and all components can be mixed evenly in batches. The water-based amino baking varnish of the present invention has the advantages of low volatile component content and simple preparation process. The formed paint film has high adhesion, high gloss, good flexibility, high impact strength, wear resistance, water washing resistance, and no paint falling, and is suitable for metal zipper heads.

Description

Technical Field

[0001] The invention relates to the technical field of water-based metal baking varnish, and in particular to a water-based amino baking varnish and a preparation method and application thereof. Background Art

[0002] Metal zipper heads are a very common type of hardware in daily life, often used in clothing and bags. At present, the zipper paints used in industrial production are mainly solvent-based paints, which contain a large amount of toxic and harmful solvents, which not only harm the health of construction workers, but also cause environmental pollution. In recent years, with the enhancement of people's environmental awareness, zipper paints have gradually developed in the direction of water-based paints, but most of the existing water-based zipper paints have problems such as poor water-washing resistance and difficulty in construction, which makes it difficult to fully meet the requirements of actual applications.

[0003] Therefore, it is of great significance to develop a water-based metal paint with excellent performance, safety and environmental protection. Summary of the invention

[0004] The purpose of the present invention is to provide a water-based amino baking varnish and a preparation method and application thereof.

[0005] The technical solution adopted by the present invention is:

[0006] A water-based amino baking varnish comprising the following components in percentage by mass:

[0007] Polyester resin: 25% to 35%;

[0008] Acrylic resin: 5% to 15%;

[0009] Film-forming aid: 10% to 15%;

[0010] Amino resin curing agent: 4% to 5%;

[0011] Adhesion promoter: 1.5% to 2%;

[0012] Wetting agent: 0.2%~0.3%;

[0013] Defoaming agent: 0.1%~0.3%;

[0014] Leveling agent: 0.5%~1%;

[0015] pH regulator: 1% to 1.5%;

[0016] Water: Balance.

[0017] Preferably, the polyester resin is a water-soluble polyester resin with a solid content of 60% to 70%.

[0018] More preferably, the polyester resin is 50630-B-70 produced by Changxing Chemical Industry (China) Co., Ltd.

[0019] Preferably, the acrylic resin is a water-soluble acrylic resin with a solid content of 60% to 70%.

[0020] More preferably, the acrylic resin is AQUALATE9104 produced by Guangdong Top Synthetic Technology Co., Ltd.

[0021] Preferably, the film-forming aid is at least one of n-butanol, ethylene glycol butyl ether and diethylene glycol butyl ether.

[0022] Preferably, the amino resin curing agent is highly methylated melamine formaldehyde resin.

[0023] Further preferably, the amino resin curing agent is at least one of Cymel 303LF from ALLNEX Corporation of the United States and Cymel MM-100 from ALLNEX Corporation of the United States.

[0024] Preferably, the adhesion promoter is a polyester adhesion promoter.

[0025] Further preferably, the adhesion promoter is 25046 from Jiangxi Longhai Chemical Co., Ltd.

[0026] Preferably, the wetting agent is a silicone wetting agent.

[0027] Further preferably, the wetting agent is at least one of RG-4100 from Changzhou Rongguan Chemical Co., Ltd. and TEGO-4100 from Germany's Digo.

[0028] Preferably, the defoaming agent is a polyether-modified silicone defoaming agent.

[0029] More preferably, the defoaming agent is at least one of TEGO-901w and TEGO-902w from Germany's Digo.

[0030] Preferably, the leveling agent is an acrylic leveling agent.

[0031] More preferably, the leveling agent is at least one of PW 336 produced by Pioneer in Germany and AX50W produced by Pioneer in Germany.

[0032] Preferably, the pH adjuster is N,N-dimethylethanolamine.

[0033] A method for preparing the water-based amino baking varnish as described above comprises the following steps: dispersing polyester resin, acrylic resin, film-forming aid and pH adjuster in water, then adding amino resin curing agent, adhesion promoter, wetting agent, defoaming agent and leveling agent and mixing and dispersing them to obtain water-based amino baking varnish.

[0034] Preferably, a method for preparing the water-based amino baking varnish as described above comprises the following steps: adding polyester resin, acrylic resin, film-forming aid and pH adjuster into water, adjusting the stirring speed to 300rpm-400rpm, stirring for 3min-5min, then adding amino resin curing agent, adhesion promoter, wetting agent, defoaming agent and leveling agent, adjusting the stirring speed to 800rpm-1000rpm, stirring for 15min-20min, and obtaining water-based amino baking varnish.

[0035] An application of the above-mentioned water-based amino baking varnish in the surface protection of metal products.

[0036] Preferably, the metal product is a metal zipper head.

[0037] The beneficial effects of the present invention are as follows: the water-based amino baking varnish of the present invention has the advantages of low volatile component content, simple preparation process, etc., and the formed paint film has strong adhesion, high gloss, good flexibility, high impact strength, wear resistance, water washing resistance, and no paint peeling, and is suitable for metal zipper heads.

[0038] Specifically:

[0039] 1) The water-based amino baking varnish of the present invention contains polyester resin and acrylic resin. The functional groups such as hydroxyl and carboxyl on the two film-forming resins can undergo curing and cross-linking reaction with the amino resin curing agent at high temperature to form a three-dimensional network macromolecular structure, which gives the paint film high density and mechanical properties as well as good water washing resistance, and is very suitable for application on metal zipper heads;

[0040] 2) The paint film formed by the water-based amino baking varnish of the present invention has good flexibility and high impact strength, and at the same time has a certain hardness and a long water resistance time;

[0041] 3) The water-based amino paint of the present invention is a single-component paint with a simple preparation process and no need for mixing before construction, which simplifies the construction process and reduces the influence of human factors;

[0042] 4) The water-based amino baking varnish of the present invention has a low content of volatile components and is safe and environmentally friendly. DETAILED DESCRIPTION

[0043] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0044] Embodiment 1:

[0045] A water-based amino baking varnish, the composition of which is shown in the following table:

[0046] Table 1 Composition of a water-based amino paint

[0047] raw material Mass percentage (%) Polyester resin 50630-B-70 30 Acrylic resin AQUALATE 9104 10 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 5 Adhesion promoter 25046 2 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1.5 water 40

[0048] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0049] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0050] Embodiment 2:

[0051] A water-based amino baking varnish, the composition of which is shown in the following table:

[0052] Table 2 Composition of a water-based amino paint

[0053] raw material Mass percentage (%) Polyester resin 50630-B-70 25 Acrylic resin AQUALATE 9104 15 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 5 Adhesion promoter 25046 2 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1 water 40.5

[0054] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0055] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0056] Embodiment 3:

[0057] A water-based amino baking varnish, the composition of which is shown in the following table:

[0058] Table 3 Composition of a water-based amino paint

[0059]

[0060]

[0061] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0062] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0063] Embodiment 4:

[0064] A water-based amino baking varnish, the composition of which is shown in the following table:

[0065] Table 4 Composition of a water-based amino paint

[0066] raw material Mass percentage (%) Polyester resin 50630-B-70 30 Acrylic resin AQUALATE 9104 10 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 4 Adhesion promoter 25046 2 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1.5 water 41

[0067] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0068] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0069] Embodiment 5:

[0070] A water-based amino baking varnish, the composition of which is shown in the following table:

[0071] Table 5 Composition of a water-based amino paint

[0072] raw material Mass percentage (%) Polyester resin 50630-B-70 30 Acrylic resin AQUALATE 9104 10 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 5 Adhesion promoter 25046 1.5 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1.5 water 40.5

[0073] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0074] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0075] Comparative Example 1:

[0076] A water-based amino baking varnish, the composition of which is shown in the following table:

[0077] Table 6 Composition of a water-based amino paint

[0078]

[0079] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0080] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 327, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0081] Comparative Example 2:

[0082] A water-based amino baking varnish, the composition of which is shown in the following table:

[0083] Table 7 Composition of a water-based amino paint

[0084]

[0085]

[0086] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0087] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent ET-581, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0088] Comparative Example 3:

[0089] A water-based amino baking varnish, the composition of which is shown in the following table:

[0090] Table 8 Composition of a water-based amino paint

[0091] raw material Mass percentage (%) Polyester resin 50630-B-70 40 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 5 Adhesion promoter 25046 2 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1.5 water 40

[0092] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0093] Add polyester resin 50630-B-70, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0094] Comparative Example 4:

[0095] A water-based amino baking varnish, the composition of which is shown in the following table:

[0096] Table 9 Composition of a water-based amino paint

[0097] raw material Mass percentage (%) Polyester resin 50630-B-70 30 Acrylic resin AQUALATE 9104 10 Ethylene glycol butyl ether 2 Diethylene glycol butyl ether 5 n-Butanol 3 Amino resin curing agent Cymel 303LF 7 Adhesion promoter 25046 2 Wetting agent RG-4100 0.3 Defoaming agent TEGO-902w 0.2 Leveling agent AX50W 1 N,N-Dimethylethanolamine 1.5 water 38

[0098] The preparation method of the above-mentioned water-based amino baking varnish comprises the following steps:

[0099] Add polyester resin 50630-B-70, acrylic resin AQUALATE 9104, ethylene glycol butyl ether, diethylene glycol butyl ether, n-butanol and N,N-dimethylethanolamine into water, adjust the stirring speed to 300 rpm, stir for 5 minutes, then add amino resin curing agent Cymel 303LF, adhesion promoter 25046, wetting agent RG-4100, defoaming agent TEGO-902w and leveling agent AX50W, adjust the stirring speed to 1000 rpm, stir for 20 minutes to obtain a water-based amino baking paint.

[0100] Performance Test:

[0101] The performance test results of the water-based amino paint in Examples 1 to 5 and Comparative Examples 1 to 4 are shown in the following table:

[0102] Table 10 Performance test results of water-based amino paint

[0103]

[0104]

[0105] Note:

[0106] Production process of paint film samples and zipper pull samples:

[0107] 1) Dilute the water-based amino paint with water to a viscosity of less than 30s, and then let it stand to defoam;

[0108] 2) Preparation of paint film sample: Spray the water-based amino paint on the tinplate with a spray gun at a pressure of 0.6MPa and a spacing of 35cm, then dry it at room temperature for 5min (avoid bubbles generated by high temperature), then bake it in an oven at 160℃ for 25min, and cool it to room temperature to obtain a paint film sample (the thickness of the paint film is 23μm±3μm).

[0109] 3) Preparation of zipper head samples: Place the surface treated zinc-aluminum alloy zipper head into a roller spray machine, start the roller, and then spray the water-based amino paint with a spray gun at a pressure of 0.6 MPa and a spacing of 35 cm for 20s to 30s, then dry the surface at room temperature for 3min, and then place it in an oven to bake at 160℃ for 10min, cool to room temperature, repeat the above operation 6 to 8 times, and bake for the last time for 25min to obtain the zipper head sample.

[0110] Adhesion: Tested in accordance with "GB / T 9286-1998 Cross-cut test for paint and varnish films";

[0111] Flexibility: Tested in accordance with "GB / T 1731-1993 Determination of paint film flexibility";

[0112] Impact strength: Tested with reference to "GB / T 1732-1993 Determination of impact resistance of paint film";

[0113] Pencil hardness: Test according to "GB / T 6739-2006 Paint and varnish pencil method for determination of paint film hardness";

[0114] Wet adhesion: Soak the paint film sample in a 1% laundry detergent solution for 5 days, then take it out and wipe it dry to test the adhesion;

[0115] Washing performance: Refer to "ASTM D2057-2005 Test method for color fastness of zippers to washing" to test the color fastness of zipper head to washing.

[0116] From Table 10, we can see that:

[0117] 1) The flexibility of the paint films formed by the water-based amino paints in Examples 1 to 5 can reach 1 mm, the impact strength can reach 100 kg·cm, and the pencil hardness can reach H or F. However, the paint films formed by the water-based amino paints in Comparative Examples 1 and 2 have high hardness, but poor flexibility and impact strength. The reason is that: low-methyl etherified melamine formaldehyde resin Cymel 327 and high-imino melamine formaldehyde resin ET-581 are added to Comparative Examples 1 and 2 respectively. These two resins contain more methylol and imino groups. When a cross-linking reaction occurs at a high temperature, a self-condensation reaction also occurs, and the cross-linking density is reduced. Therefore, the flexibility of the paint film formed is worse;

[0118] 2) Compared with Example 1, Example 2 and Example 3 change the ratio of the two film-forming resins, and change the mass ratio of polyester resin to acrylic resin to 25:15 and 35:5. It can be seen that when the mass ratio of polyester resin to acrylic resin is within the range of 25 to 30:10, the hardness of the paint film can reach H, the flexibility can reach 1mm, the impact strength can reach 100kg·cm, the wet adhesion can reach Level 2, and the color fastness to water washing can be achieved. When the mass ratio of polyester resin to acrylic resin is 35:5, the mechanical properties are slightly worse, but the color fastness to water washing can also be achieved. The reason is that different film-forming resins have different molecular structure characteristics, which will eventually lead to different properties of the paint film. Generally, in the amino paint system, polyester resin has better flexibility but lower hardness, and acrylic resin has higher hardness but slightly worse flexibility. Therefore, when no acrylic resin is added to Comparative Example 3, the hardness is low and the washing performance is slightly poor, which cannot meet the performance requirements;

[0119] 3) In Example 4, based on Example 1, the dosage of the amino resin curing agent is changed from 5% to 4%, and there is no obvious difference in the properties of the paint film, indicating that when the dosage of the curing agent is in the range of 4% to 5%, the degree of curing and crosslinking of the system is not much different. When the dosage of the curing agent is increased to 7% in Comparative Example 4, the water resistance of the paint film deteriorates and the water washing performance is very poor. This is mainly because the excess curing agent cannot react and remains in the paint film, affecting the density of the paint film. In Example 5, based on Example 1, the dosage of the adhesion promoter 25046 is changed from 2% to 1.5%, and there is no obvious change in the adhesion of the paint film, indicating that the dosage of the adhesion promoter in the range of 1.5% to 2% can play a good role in improving the adhesion of the paint film.

[0120] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A water-based amino baking varnish, characterized in that: The following components are included in mass percentage: Polyester resin: 25%~35%; Acrylic resin: 5% to 15%; Film-forming aid: 10% to 15%; Amino resin curing agent: 4% to 5%; Adhesion promoter: 1.5% to 2%; Wetting agent: 0.2%~0.3%; Defoaming agent: 0.1%~0.3%; Leveling agent: 0.5%~1%; pH adjuster: 1% to 1.5%; Water: balance; The polyester resin is 50630-B-70 from Changxing Chemical Industry (China) Co., Ltd.; The acrylic resin is AQUALATE 9104 produced by Guangdong Top Synthetic Technology Co., Ltd.; The amino resin curing agent is Cymel 303LF from ALLNEX Corporation of the United States; The adhesion promoter is 25046 from Jiangxi Longhai Chemical Co., Ltd.

2. The water-based amino baking varnish according to claim 1, characterized in that: The film-forming aid is at least one of n-butanol, ethylene glycol butyl ether and diethylene glycol butyl ether.

3. The water-based amino baking varnish according to claim 1, characterized in that: The wetting agent is an organosilicon wetting agent; the defoaming agent is a polyether-modified organosilicon defoaming agent; and the leveling agent is an acrylate leveling agent.

4. The water-based amino baking varnish according to claim 1, characterized in that: The pH regulator is N,N-dimethylethanolamine.

5. A method for preparing a water-based amino baking varnish as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: The polyester resin, acrylic resin, film-forming aid and pH adjuster are dispersed in water, and then the amino resin curing agent, adhesion promoter, wetting agent, defoaming agent and leveling agent are added and mixed and dispersed to obtain a water-based amino baking varnish.

6. Use of the water-based amino baking varnish as claimed in any one of claims 1 to 4 in the surface protection of metal products.

Images