WO2017200139A1 - Urethane-based paint composition and method for preparing self-healing urethane-based paint using same - Google Patents

Abstract

A urethane-based paint composition of the present invention comprises a main agent containing a polyol having a hydroxyl group (-OH) value of 20-120 mgKOH/g and a curing agent containing an isocyanate, wherein the equivalent ratio (NCO/OH) of an isocyanate group (-NCO) of the isocyanate to the hydroxyl group (-OH) of the polyol is 0.30-0.65.

Description

Urethane-based paint composition and method for producing self-recoverable urethane-based paint using the same

The present invention relates to a urethane-based coating composition and a method for producing a self-resilient urethane-based coating using the same, and more particularly, to a urethane-based coating composition comprising a main agent containing a polyol and a curing agent containing an isocyanate and using the same A manufacturing method for producing a urethane-based paint having good self-resilience.

In addition to automobiles, products such as liquid crystals, optical lenses, cosmetics, sporting goods, household appliances, fine musical instruments, furniture and the like are very susceptible to scratches such as scratches on their transportation and use. Since scratches caused by such scratches significantly reduce the appearance of the product, various studies are actively conducted to prevent product damage due to physical and chemical effects from the outside by coating various resin compositions on the surface of such products.

As one method for preventing the above-mentioned scratches, the conventional hard coating product has a problem that the restoration is not restored once scratches are generated. In addition, even a soft coating product has a problem that takes a long time to restore the surface to its original state or require heat treatment. In addition, the material properties such as transparency, bending resistance, MEK (methyl ethyl ketone) resistance, tanol resistance, and fouling resistance are poor, there was a problem that it is difficult to effectively implement in the industrial field.

The present invention is to solve the above problems, the urethane-based coating composition capable of producing a urethane-based paint having excellent self-recovery (self-healing), good appearance and excellent stain resistance and a method for producing a urethane-based paint using the same It aims to provide.

The above and other objects and advantages of the present invention will become more apparent from the following description of the preferred embodiments.

The urethane-based coating composition according to one aspect of the present invention includes a main agent containing a polyol having a hydroxyl group (-OH) value of 20 to 120 mgKOH / g and a curing agent containing an isocyanate, and a hydroxyl group (-OH) of the polyol. It is characterized in that the equivalent ratio (NCO / OH) of the isocyanate group (-NCO) of the isocyanate to () is 0.30 ~ 0.65.

The urethane-based coating composition according to another aspect of the present invention contains a main agent and a curing agent, and the main agent has a hydroxyl value of 20 to 120 mgKOH / g, a glass transition point (Tg) of -20 to 160 ° C, and a weight average molecular weight ( Mw) contains a polycarbonate polyol of 1,000 to 200,000, characterized in that the curing agent contains an isocyanate.

According to still another aspect of the present invention, there is provided a method of preparing a urethane-based paint, the method including: providing a subject containing a polyol having a hydroxyl value of 20 to 120 mgKOH / g; Providing a curing agent containing isocyanate; And blending the main agent and the curing agent such that the equivalent ratio (NCO / OH) of the isocyanate group of the isocyanate to the hydroxyl group of the polyol is 0.30 to 0.65.

Urethane-based paints prepared using the urethane-based paint compositions according to the invention provide very good self-resilience. It also provides excellent material properties as a coating film, such as transparency, flex resistance, MEK (methyl ethyl ketone) resistance, tanol resistance and fouling resistance, and the like.

According to the present invention, a urethane-based paint composition and a method for producing a urethane-based paint using the same will be described below. In the preferred embodiment of the present invention will be described in detail by specifying the type of each component material, which is intended to explain in detail enough to enable those skilled in the art to easily practice the present invention, This does not mean that the technical spirit and scope of the present invention is limited, the scope of the present invention is specified by the claims.

The urethane-based coating composition of the present invention contains a main agent and a curing agent. The main material contains a polyol having a hydroxyl value (-OH) of 20 to 120 mgKOH / g and various additives (curing catalyst, surface conditioner, antifoaming agent, light absorbing agent / ultraviolet absorbing agent, etc.), and the curing agent isocyanate having an isocyanate group (-NCO). It contains.

Examples of the polyol contained in the main material include a polyester polyol, a polyether polyol, a polycarbonate polyol, and an acrylic polyol having a glass transition temperature (Tg) of -20 ° C to 160 ° C and a weight average molecular weight (Mw) of 1,000 to 200,000. Or a combination thereof, but is not limited thereto.

Curing catalysts as additives that may be contained in the subject include, but are not limited to, metal-based (inorganic) curing catalysts based on tin, zirconium, aluminum, and zinc or amine (organic) curing catalysts. The surface modifier improves the coating property and level of the coating film and prevents bubbles from remaining in the coating film. The surface modifier may be polysiloxane, acrylic resin, fluorocarbon resin, or modified substances thereof, but is not limited thereto. As the light absorbing agent, hindered amine light absorbing agents (HALS) may be used. As the ultraviolet light absorbing agent, ultraviolet absorbers such as imides, benzotriazoles, benzophenones, triazines, and hydrazines may be used. no. In addition, the additive contained in the subject matter is not limited to a curing catalyst, a surface conditioner, a light stabilizer and an ultraviolet absorber, and it is conventionally known in the art that the antioxidant, the wetting agent, and the like may optionally and additionally contain other additives. It will be obvious to the technician.

Isocyanate contained in the curing agent may be a compound as described in the table below, but is not limited thereto.

Example  1 to 4

In Examples 1 to 4 of the present invention, the main ingredient and the curing agent are blended while changing the equivalent ratio (NCO / OH) of the hydroxyl group of the polyol contained in the main ingredient and the isocyanate group of the isocyanate contained in the curing agent within the range of 0.30 to 0.65. It was. The urethane-based paint formulation thus obtained was diluted with an organic solvent and coated on a substrate, followed by heat drying. The self restoring property, appearance, and stain resistance of the urethane coating film thus obtained were evaluated.

More specifically, in Examples 1 to 4 of the present invention, as an example of the polyol, 1,6-hexamethylene diisocyanate (HDI) as a main ingredient containing a polycarbonate polyol having a hydroxyl value of 20 to 120 mgKOH / g and an example of isocyanate ) Was blended so that the equivalent ratio (NCO / OH) of the isocyanate group and the hydroxyl group was in the range of 0.30 to 0.65 as shown in Table 2 below. The urethane-based paint was diluted by diluting 81.4 parts by weight of the urethane-based paint compound blended with 18.6 parts by weight of an aromatic organic solvent. The amount of the additive in the paint formulation was 1.4 parts by weight relative to 80 parts by weight of the paint formulation.

Example	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
NCO / OH ratio	0.33	0.48	0.54	0.65	0.21	0.25	0.75

The urethane-based paint thus obtained was applied by a spray method on a transparent acrylic plate (PMMA plate) having a thickness of 1.0 mm and a PET transparent film having a thickness of 100 um with a predetermined thickness (thickness which can have a thickness of 15 um after drying) at 75 ° C. Heat dried for 30 minutes. After 7 days after the heat drying, the appearance, self-resilience and fouling resistance of the coated urethane-based coating was evaluated, and the results are summarized in Table 3.

Example	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3
NCO / OH ratio	0.33	0.48	0.54	0.65	0.21	0.25	0.75
Appearance Evaluation	○	○	○	○	△ (sticky)	△ (sticky)	○
Transparency	○	○	○	○	△ (cloudy)	○	○
Cross Cut Test (1mm)	100/100	100/100	100/100	100/100	100/100	100/100	100/100
Flex resistance (PET film)	○	○	○	○	○	○	○
Resiliency	○	○	○	○	×	×	×
MEK resistance	○	○	○	○	×	△	×
5% ethanol	○	○	○	○	×	△	×
Artificial Sweat (Alkali pH 8.0)	○	○	○	○	×	×	△
Artificial sweat (acidic pH 5.5)	○	○	○	○	×	×	△
Magic resistance	○	○	○	○	×	×	△

As can be seen from Table 3, in Examples 1 to 4 included in the equivalent ratio (NCO / OH) range of the present invention, appearance evaluation, transparency, cross cut test, bending resistance, stability, In all evaluation items such as methyl ethyl ketone, ethanol, sweat, etc., all of the evaluation items showed good to excellent results, but especially in the comparative examples where the equivalent ratio (NCO / OH) was outside the range of 0.30 to 0.65, There was a problem in the surface area, and there was also a problem in appearance evaluation and contamination resistance.

From the above, the urethane-based coating film of the present invention prepared by blending a polyol-containing main agent and an isocyanate-containing curing agent such that the equivalent ratio (NCO / OH) of the isocyanate group to the hydroxyl group is within the range of 0.30 to 0.65 does not apply heat or the like. Even if it does not have excellent self-healing resistance to scratches, it can be seen that other appearance and contamination resistance is excellent.

Hereinafter, each quality item and evaluation criteria shown in the said Table 3 are demonstrated.

-"Appearance Evaluation" item is a visual evaluation of whether the coating film has gloss, stains, wrinkles, bends, grains, and stickiness. "○" represents "no abnormality", "△" represents "slightly abnormal", "x" represents "ideal", and the same also applies to other evaluation items below.

-"Transparency" item is a visual evaluation of the presence of flow, stains, etc. on the transparent PMMA plate coated surface.

-The `` Cross Cut Test (1mm) '' item is an ISO (International Organization for Standardization) that cuts the coated coating film into a lattice shape (checker board) and attaches and removes the tape to the coating film to test whether the coating film is separated from the substrate. ) According to 2409, it is evaluated to be good when 'film remaining number / 100 eyes = 100/100'.

-"Bending resistance (PET film)" item is evaluated through the cylindrical mandrel bending test according to ISO 1519. That is, the peeling or coating abnormality was confirmed and evaluated by using a bending tester employing a mandrel having a diameter of 2 mm for the coated PET film.

-"Resiliency" item is to evaluate the resiliency when the coating brush is reciprocated 10 times by applying 500g weight to the brass brush.

-"MEK (methyl ethyl ketone) resistance" item is a surface rubbing test after 30 rubbing tests with gauze moistened with MEK.

-"5% Ethanol" item is to evaluate the surface condition after performing the friction test 30 times with gauze containing 5% ethanol.

-"Artificial sweat (alkaline pH 8.0)" item is prepared by dropping artificial sweat (alkaline) on the surface, left for 4 hours, and then wiped and evaluated the surface condition.

-"Artificial sweat (acidic pH 5.5)" item is prepared by dropping artificial sweat (acidic) on the surface, left for 4 hours, wiped off, and then evaluated the surface condition.

-"Magic Resistance" item is to evaluate the surface condition after contaminating the coating film with oily magic (black), wiping it with alcohol after 1 hour.

In Examples 1 to 4 of the present invention, although a main agent containing polycarbonate polyol and a curing agent containing 1,6-hexamethylene diisocyanate (HDI) were used, other materials such as polyester polyol, polyether polyol, acrylic polyol and the like were used. It will be apparent to those skilled in the art that polyols and other isocyanate curing agents shown in Table 1 may optionally be used as needed.

In addition, the present embodiment is based on the premise that a two-part type curing agent containing a main ingredient and an isocyanate containing a polyol and an additive is not limited thereto.

Example  5 to 8

In the present examples, a urethane-based coating was prepared by mixing a main body and a 1,6-hexamethylene diisocyanate (HDI) curing agent in a predetermined equivalent ratio while changing the type of the polyol, and evaluated the resilience and appearance of the prepared urethane-based coating. .

Specifically, a main body containing polyester polyol and an additive (Example 5), a main body containing a polyether polyol and an additive (Example 6), a main body containing a polycarbonate polyol and an additive (Example 7), an acrylic polyol And the main ingredient (Example 8) containing an additive were blended so that the equivalent ratio of a 1, 6- hexamethylene diisocyanate (HDI) hardener, an isocyanate group, and a hydroxyl group might be about 0.48, respectively. 81.6 parts by weight of this urethane paint composition was diluted with 18.4 parts by weight of an aromatic organic solvent. Dilute urethane-based paints were spray-coated on a substrate as in Examples 1 to 4, and thermally dried to evaluate appearance and recoverability. The evaluation results are summarized in Table 4 below.

	Example 5	Example 6	Example 7	Example 8
Polyols in the Theme	Polyester polyol	Polyether polyols	Polycarbonate polyol	Acrylic polyol
Hardener	HDI	HDI	HDI	HDI
NCO / OH	0.48	0.48	0.48	0.48
Appearance evaluation	○	○	○	○
Cross Cut Test (1mm)	100/100	100/100	100/100	100/100
Stability 20 ° C (sec)	15-20	10-15	<1	<3

As can be seen from Table 4, the urethane-based coating films prepared from the urethane-based coating compositions of Examples 5 to 8 all had excellent to good appearance and excellent cross-cut test results. In addition, the restoring properties were all excellent to good. Among them, urethane-based paints prepared using the main material containing polycarbonate polyols showed the best resilience.

Therefore, it can be seen that it is most preferable to employ a polycarbonate polyol as the polyol included in the subject matter in terms of resilience.

As described above, the present invention has been described by means of specific embodiments, but the present invention is not limited to these embodiments, and it is within the equivalent scope of the spirit and claims of the present invention by those skilled in the art. It should be understood that various modifications and variations can be made in the present invention. In addition, it should be understood that various such modifications and variations fall within the scope of the present invention.

Since the urethane-based coating film prepared by the urethane-based coating composition of the present invention has excellent self-resilience, transparent appearance and excellent stain resistance, it can be used very effectively as a coating material for a wide range of products such as automobiles, liquid crystals, optical lenses, home appliances, etc. have.

Claims (13)

1. A urethane-based coating composition comprising a main agent containing a polyol having a hydroxyl group (-OH) value of 20 to 120 mgKOH / g and a curing agent containing an isocyanate,

   The urethane-based coating composition, characterized in that the equivalent ratio (NCO / OH) of the isocyanate group (-NCO) of the isocyanate to the hydroxyl group (-OH) of the polyol is 0.30 to 0.65.
2. The method of claim 1,

   The said polyol is 1 type, or 2 or more types of polyester polyol, polyether polyol, polycarbonate polyol, and acrylic polyol whose glass transition point (Tg) is -20 degreeC-160 degreeC, and a weight average molecular weight (Mw) is 1,000-200,000. Urethane-based paint composition comprising a.
3. The method according to claim 1 or 2,

   The isocyanate of the curing agent is one or two of 1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and 4,4-diphenylmethane diisocyanate (MDI). Urethane type coating composition containing the above.
4. The method according to claim 1 or 2,

   The subject is a urethane-based coating composition further comprising a metal-based curing catalyst, or an amine-based curing catalyst mainly composed of tin (Sn), zirconium (Zr), aluminum or zinc.
5. The method according to claim 1 or 2,

   The said subject further contains the urethane type coating composition which contains the surface modifier containing polysiloxane, an acrylic resin, a fluororesin, or these modified bodies.
6. The method according to claim 1 or 2,

   The said subject is a urethane type coating composition which further contains a hindered amine light stabilizer (HALS) and an amide type, a benzotriazole type, a benzophenone type, a triazine type, or a hydrazine type ultraviolet absorber.
7. As a urethane type coating composition containing a main body and a hardening | curing agent,

   The subject contains a polycarbonate polyol having a hydroxyl value of 20 to 120 mgKOH / g, a glass transition point (Tg) of -20 to 160 ° C, and a weight average molecular weight (Mw) of 1,000 to 200,000,

   The curing agent is a urethane-based coating composition, characterized in that it contains isocyanate.
8. The method of claim 7, wherein

   Urethane-based paint composition, characterized in that the equivalent ratio (NCO / OH) of the isocyanate group of the isocyanate to the hydroxyl group of the polycarbonate polyol is 0.30 ~ 0.65.
9. The method according to claim 7 or 8,

   The isocyanate is selected from one, two or more of 1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and 4,4-diphenylmethane diisocyanate (MDI). Urethane-based paint composition comprising a.
10. The method according to claim 7 or 8,

    The subject is a urethane-based coating composition further comprising a metal-based curing catalyst, or an amine-based curing catalyst mainly composed of tin (Sn), zirconium (Zr), aluminum or zinc.
11. The method according to claim 7 or 8,

    The said subject further contains the urethane type coating composition which contains the surface modifier containing polysiloxane, an acrylic resin, a fluororesin, or these modified bodies.
12. The method according to claim 7 or 8,

    The said subject is a urethane type coating composition which further contains a hindered amine light stabilizer (HALS) and an amide type, a benzotriazole type, a benzophenone type, a triazine type, or a hydrazine type ultraviolet absorber.
13. Providing a subject containing a polyol having a hydroxyl value of 20-120 mgKOH / g;

    Providing a curing agent containing isocyanate; And

    Blending the main agent and the curing agent such that the equivalent ratio (NCO / OH) of the isocyanate group of the isocyanate to the hydroxyl group of the polyol is 0.30 to 0.65

    Method of producing a urethane-based paint comprising a.