TW202035599A - Method for coating water-based paint capable of quickly drying the paint and significantly reducing equipment costs and production time - Google Patents

Abstract

A method for coating a water-based paint, which includes the following steps of: forming a water-based paint on a substrate in a coating manner; subjecting the water-based paint to natural drying within 3 minutes at room temperature to form a primer coat when indoor room temperature is greater than 18 DEG C, wherein the TG point (glass transition temperature) of the water-based resin selected for the water-based paint must be controlled between 50 DEG C and 100 DEG C, and within 3 minutes of natural drying of the water-based paint, a lacquer coat is formed on the primer coat; when at least two or more water-based resins are selected, the TG point is at least one of 35-80 DEG C, the TG point is at least one of 80-120 DEG C, and the average value of the TG point of the mixed water-based resins is between 50 DEG C and 100 DEG C.

Description

Coating method of water-based paint

The present invention relates to a coating method, and particularly relates to a coating method of water-based paint.

Generally on various buildings or various furniture, decorations, electronic products, daily necessities and other objects, in order to have a more beautiful appearance and a sense of value, various colors and graphics are often painted with paint on the exterior to have a higher The sense of value and more beautiful visual experience.

The commonly used paint is oil-based paint. The oil-based paint mainly contains eight heavy metals (lead, antimony, arsenic, barium, cadmium, chromium, mercury, selenium), which can be diluted with banana water or pine perfume solvent when it is used. On buildings or various decorations, furniture, electronic products, daily necessities, etc. However, the oil-based paint itself is toxic due to the heavy metals contained in it, and the banana water or pine perfume (ie toluene, xylene) used for its dilution is also toxic, which will not only cause health problems to the constructors or users Great influence, and because the above-mentioned components have combustion-supporting properties, a little carelessness in construction will cause fire hazards. At the same time, because the components are all extracted from petroleum, under the influence of the current gradual shortage of energy It is urgent to find alternative raw materials.

Nowadays, many paints tend to be water-based paints, which can improve the hazards of toxic substances in oil-based paints. For example, a patent document (application number: TW 097150813) discloses a water-based coating composition, which includes a water-soluble resin and a bridging agent. The above water-soluble resin is uniformly dispersed in a water-soluble solvent after amination, and the water-soluble resin is selected from one of the following or any combination thereof: acrylic resin, alkyd resin, epoxy resin, polyurethane resin and polyester Resin. The above-mentioned bridging agent has at least the function of promoting the reaction and bridging the water-soluble resin and the coating, and the function of the bridging agent is to force the water-soluble resin to dry or dry naturally. The above patent documents further disclose a method for coating the surface of a substrate, which includes: Coating the water-based coating composition on the surface of the substrate; and performing a drying process to dry the water-based coating composition.

However, if the above-mentioned water-based paint is dried in a natural drying manner, the natural drying time of the water-based paint often needs more than 10 minutes before the next coating process can be performed. As a result, the natural drying time of the water-based paint that exceeds 10 minutes will delay the process of the next coating.

Therefore, there is a need for a coating method that can quickly dry the water-based paint naturally, which can solve the aforementioned problems.

One of the objects of the present invention is to provide a coating method which can quickly and naturally dry water-based paint.

According to the above objective, the present invention provides a coating method for water-based paint, which includes the following steps: forming a water-based paint on a substrate by coating; and when the temperature in a room is greater than 18 degrees Celsius, the water-based paint Dry naturally at the room temperature and within 3 minutes to form a primer coating, wherein the TG point (glass transition temperature) of the water-based resin selected for the water-based paint must be controlled between 50°C and 100°C; and Within 3 minutes of natural drying of the water-based paint, a top coat layer is formed on the primer coat layer.

The coating method of the water-based paint of the present invention can quickly and naturally dry the water-based paint of the primer coating, and the next topcoat coating process can be carried out. Since the drying method of the primer coating uses natural drying and does not need to use forced drying (such as low-temperature baking and medium-high temperature baking), the coating method of the water-based paint of the present invention can greatly reduce equipment cost and process time.

According to the coating method of the water-based paint of the present invention, the water-based paint of the primer coating can be quickly dried at room temperature and naturally within 3 minutes, and the next topcoat coating process can be carried out. In this way, the natural drying time of the water-based paint within the above 3 minutes will not delay the process of the next topcoat coating.

10‧‧‧Water-based paint

10’‧‧‧ Primer coating

11‧‧‧Water-based paint

11’‧‧‧Top paint coating

12‧‧‧Substrate

S100~S300‧‧‧Step

Fig. 1 is a flowchart of a coating method of water-based paint according to an embodiment of the present invention.

2 is a schematic cross-sectional view of a coating method of a water-based paint according to an embodiment of the present invention, which shows that the water-based paint is formed on a substrate and the water-based paint is formed into a primer coating.

3 is a schematic cross-sectional view of a coating method of a water-based paint according to an embodiment of the present invention, which shows that a topcoat layer is formed on the primer coating layer.

In order to make the above-mentioned objectives, features and characteristics of the present invention more obvious and understandable, the relevant embodiments of the present invention are described in detail below in conjunction with the drawings.

Please refer to FIG. 1, which shows a flow chart of a coating method of a water-based paint according to an embodiment of the present invention. The coating method includes the following steps: referring to FIG. 2, in step S100, an aqueous coating 10 is formed on a substrate 12 by coating. The water-based paint 10 includes water-based resin, paint additives, color paste, and the balance is water. For example, the water-based resin may be selected from one or two of acrylic resin, polyurethane dispersion resin and water-based polyurethane (PUD) resin. The coating additive is selected from one of the following or any combination thereof: water-based defoaming agent, water-based leveling agent, water-based wetting and dispersing agent, water-based thickening agent, adhesion agent, de-pinhole additives, neutralizing agent, matting Powder, antibacterial auxiliary and anti-settling agent.

The water-based defoamer can be selected from one of: polyether-siloxane copolymer emulsion (containing white smoke), xylene polysiloxane emulsion (containing white smoke) and polyether-siloxane copolymer emulsion or Two types (without silicon dioxide). The water-based leveling agent can be selected from one or two of polyether-siloxane copolymers, fluorine-modified leveling agents and organic modified polysiloxanes. The water-based wetting and dispersing agent can be selected from one or two of silicone surfactants, polyhydroxy-amide composition and polyacrylate sodium salt dispersing agent. The water-based thickener can be selected from one or two of swelling thickeners, non-ionic polyurethane thickeners and associative polyurethane (PU) thickeners. The adhesive may be a polyester copolymer.

The coating method adopts bar coating, sloping coating, curtain coating and spray coating. coating). Preferably, when spray coating is adopted as the coating method, it has better leveling properties. The substrate can be a plastic material or a metal material. For example, the plastic material is at least one of acrylonitrile-butadiene-styrene copolymer (Acrylonitrile-Butadine-Styrene, ABS) or polypropylene (Polypropylene, PP).

Please refer to Figure 2 again. In step S200, when an indoor temperature is greater than 18 degrees Celsius, the water-based paint 10 is naturally dried (that is, without baking) at the indoor temperature and within 3 minutes to form a bottom Lacquer coating 10'. The film thickness of the primer coating 10' can be controlled below 25 m.

The TG point (glass transition temperature) of the water-based resin selected for the water-based paint 10 must be controlled between 50°C and 100°C. When the TG point (glass transition temperature) of the water-based resin is less than 50°C, the water-based paint 10 will exceed 3 minutes of natural drying time due to slow drying; when the TG point (glass transition temperature) of the water-based resin is greater than 100°C, the Although the water-based paint 10 dries quickly, the surface is rough. When the water-based paint 10 is mixed with at least two or more water-based resins, at least one of the TG point (glass transition temperature) is between 35℃ and 80℃, and at least one TG point (the glass transition temperature) is between 80℃ and 120℃. The average value of the TG point (glass transition temperature) of the resin is between 50°C and 100°C, and it can be used together as needed to adjust the drying speed and surface hardness. More preferably, the average value of the TG point (glass transition temperature) of the water-based resins of the water-based paint 10 is between 65°C and 90°C.

For example, when the indoor temperature is greater than 18 degrees Celsius, the water-based paint 10 can naturally dry within 3 minutes to form the primer coating 10'. As the indoor temperature is higher, the time for the water-based paint 10 to dry naturally is shorter. The following two water-based paint formulations can achieve the above-mentioned effects: The formulation of the first water-based paint: the first water-based resin (such as acrylic resin) 50KG, the second water-based resin (such as polyurethane dispersion resin) 50KG, the first antifoaming agent (such as polyether-silicone copolymer Emulsion) 0.4KG, adhesive 2KG, matting powder 4KG, second defoamer (e.g. xylene polysiloxane emulsion) 1.2KG, reverse osmosis (RO) water 4KG, pinhole removal aid 0.5KG, black Color paste 11KG. The second water-based paint formulation: reverse osmosis (RO) water 10KG, defoamer (such as polyether-silicone copolymer emulsion) 0.2KG, silver color paste 3.4KG, first water-based resin (such as acrylic resin Grease) 41KG, second water-based resin (for example, polyurethane dispersion resin) 41KG, anti-settling agent 2.6KG, and adhesion agent 2KG.

The coating method of the water-based paint of the present invention can quickly and naturally dry the water-based paint of the primer coating, and the next topcoat coating process can be carried out. Since the drying method of the primer coating uses natural drying and does not need to use forced drying (such as low-temperature baking and medium-high temperature baking), the coating method of the water-based paint of the present invention can greatly reduce equipment cost and process time.

Referring to FIG. 3, in step S300, within 3 minutes when the water-based paint is naturally dried, a top coat 11' is formed on the primer coat 10'. In this embodiment, the top coat 11' uses another water-based paint 11 and is formed on the primer coat 10' by coating. The composition ratio of the water-based paint 11 used in the topcoat layer 11' can be similar to that of the aforementioned water-based paint 10. The coating method adopts at least one of bar coating, slidc coating, curtain coating, and spray coating. Preferably, when spray coating is adopted as the coating method, it has better leveling properties. In another embodiment, the topcoat layer 11' can be a solvent-based coating and is formed on the primer coating layer 10' by coating. The drying method of the topcoat 11' can be natural drying or forced drying (such as low-temperature baking and medium-high temperature baking).

After the top coat 11' and the primer coat 10' are cured, the adhesion test can be performed. The adhesion between the primer coating 10' and the substrate 12 is 5b (that is, the two cannot be peeled off). The adhesion between the top coat 11' and the primer coat 10' is also 5b, that is, the two cannot be peeled off.

According to the coating method of the water-based paint of the present invention, the water-based paint of the primer coating can be quickly dried at room temperature and naturally within 3 minutes, and the next topcoat coating process can be carried out. In this way, the natural drying time of the water-based paint within the above 3 minutes will not delay the process of the next topcoat coating.

To sum up, it only describes the preferred implementations or examples of the technical means adopted by the present invention to solve the problems, and is not used to limit the scope of implementation of the patent of the present invention. That is to say, everything that is consistent with the scope of the patent application of the present invention, or according to The equal changes and modifications made to the scope of the patent of the present invention are all covered by the scope of the patent of the present invention.

S100~S300‧‧‧Step

Claims (10)

A coating method of water-based paint, including the following steps: forming a water-based paint on a substrate in a coating manner; when an indoor temperature is greater than 18 degrees Celsius, the water-based paint is carried out at the indoor temperature and within 3 minutes Naturally dry to form a primer coating, wherein the TG point (glass transition temperature) of the water-based resin selected for the water-based paint must be controlled between 50°C and 100°C; and within 3 minutes when the water-based paint is naturally dried , Form a top coat of paint on the primer coat. For the coating method of water-based paint described in item 1 of the scope of patent application, when the water-based paint is mixed with at least two or more water-based resins, the TG point (glass transition temperature) is at least one of 35℃~80℃, and the TG point ( Glass transition temperature) is at least one of 80°C~120°C, and the average value of the TG point (glass transition temperature) of the mixed water-based resin is between 50°C and 100°C. The coating method of water-based paint as described in item 2 of the scope of patent application, wherein the average TG point (glass transition temperature) of the water-based resins of the water-based paint is between 65°C and 90°C. The coating method of water-based paint as described in the first item of the scope of patent application, wherein the topcoat layer uses another water-based paint and is formed on the primer coating layer by coating. The coating method of water-based paint as described in item 4 of the scope of patent application, wherein the above-mentioned coating method adopts spray coating. According to the application method of the water-based paint described in the first item of the scope of the patent application, the top coat layer uses a solvent-based paint and is formed on the primer coat by coating. The coating method of water-based paint as described in item 6 of the scope of patent application, wherein the above-mentioned coating method adopts spray coating. The coating method of water-based paint as described in item 1 of the scope of patent application, wherein the bottom The adhesion between the lacquer coating and the substrate is 5b. The coating method of water-based paint as described in item 8 of the scope of patent application, wherein the adhesion between the top coat and the primer coat is also 5b. The coating method of water-based paint as described in item 1 of the scope of patent application, wherein the substrate is a plastic material or a metal material.

Images