KR20100135089A - Manufacturing method of scratch self-recovering composition - Google Patents

Abstract

PURPOSE: A scratch self-recovering coating agent composition is provided to ensure transparent coating film and strong elasticity and to recovery weak scratch caused by strong elasticity in a short time. CONSTITUTION: A method for preparing a scratch self-recovering coating agent composition comprises the steps of: (S100) preparing a polyurethane prepolymer by reacting a reactant including trimethylene oxide; (S102) preparing a polyester prepolymer by reacting a reactant including chitosan; and (S104) mixing 20 ~ 60 parts by weight of the polyurethane prepolymer prepared by (S100) step with 100.0 parts by weight of the polyurethane prepolymer prepared by (S102) step.

Description

Manufacturing method of scratch self-recovering composition

The present invention relates to a method for preparing a scratch self-healing coating, and more particularly, to add a trimerylene oxide and chitosan to a polyurethane compound and a polyester compound to allow scratches caused by external stress to heal and restore itself. The scratch self-healing coating solves the problem that the self-healing of the scratches was no longer possible because the molecular structure was completely destroyed beyond the scratch recovery threshold, so that the broken molecular structure formed new intermolecular bonds, even for relatively strong scratches, to prevent the strong scratches. The present invention relates to a method for preparing a scratch self-healing coating, in which scratches can be restored and healed up to scratching.

In the prior art, Korean Patent Registration No. 10-0691858 discloses a ladder structure of silicone-acrylic-urethane when it reacts with isocyanate by containing silicone-acrylic in the molecule to form a strong elastomeric structure, thereby restoring the ability to resist external stress. It is adopted in the mechanism to recover the scratches by scratch, but it shows the phenomenon that the scratches are partially recovered and repaired for light scratches, including the alcohol rubbing resistance of coating water, chemical resistance, mechanical strength, hardness, cosmetic resistance, and drying speed delay. The mechanical and physicochemical basic properties of the coating material and the processing properties such as drying are poor, making it difficult to use effectively in the industry.

In addition, the Republic of Korea Patent No. 10-0643335 attempts to improve the scratch self-healing performance due to the urethane molecular structure formed by the reaction of acryl, aliphatic polyester, silicone-acrylate and isocyanate, but chemical resistance including low coating hardness Compared to the existing products, the back was significantly lowered, and the drying rate was lowered, resulting in poor industrial coating.

In Japanese Laid-Open Patent Publication No. 2000-293895, in order to improve the problem of preventing scratches such as scratches, it is possible to improve scratch resistance by using a surface treated silica and a photocurable acrylate. Self-recovery and self-healing not only showed, but also the introduction of silica revealed a problem of deterioration of optical properties and surface contamination of the surface appearance. In Japanese Patent Laid-Open Publication No. 11-293159, which attempts to improve scratch resistance and stain resistance at the same time, the purpose of improving the stain resistance by adding a fluorine-based compound can be achieved, whereas the coating film is deteriorated, indicating problems such as surface scratches. When coating, there is a problem that the compatibility with the base coat is lowered.

The technical problem to be achieved by the present invention is to heal the external weak scratches due to strong elasticity in a short time when scratching of the coating surface occurs, as well as to heal through the new bond between the scratch molecules for strong scratches enough to break the molecular chain. It is to provide a method of producing a scratch self-healing coating having a performance and a coating.

Method for producing a scratch self-healing coating agent according to the present invention for achieving the above technical problem,

(a) preparing a polyurethane prepolymer by reacting with trimethylene oxide, (b) preparing a polyester prepolymer by reacting with chitosan, and (c) preparing in step (b) It characterized in that it comprises a step of mixing 20 to 60 parts by weight of the polyurethane prepolymer prepared in step (a) based on 100 parts by weight of the polyester prepolymer.

The scratch self-healing coating agent according to the present invention is very transparent and strong in coating coating, and when scratches of the coating surface caused by external force occur, the weak elastic scratches caused by the strong elasticity are restored within a short time, and the degree of breaking the molecular chain is short. Even for strong scratches, the new bonds between the intermolecular molecules result in restorative healing. In addition, there is an effect that can exhibit excellent coating properties even in the chemical resistance, weather resistance, cosmetic resistance, etc. that has been pointed out as a problem of the conventional self-healing coating agent without lowering the gloss characteristics.

Figure 1 is a simplified flow diagram of the main process for producing a scratch self-healing coating according to the present invention. Referring to FIG. 1, first, a reaction is performed including trimethylene oxide to prepare a polyurethane prepolymer (step S100). Preferably one selected from cyclonuclear diisocyanate, isophorone diisocyanate, nuxa methylene diisocyanate, or a combination thereof, trimethylene oxide, neopentyl glycol, 1,6-nucleic acid diol, trimethylol glycol, ethylene propylene block Polyol or the like is reacted to prepare a polyurethane prepolymer such that a hydroxyl group is present at the terminal.

The step (S100) is, for example, using at least one cyclonucleic acid diisocyanate, isophorone diisocyanate, nucleomethylene diisocyanate and in the absence of a catalyst or in the presence of tributyltin catalyst or tertiary amine catalyst, trimethylene oxide, neopentyl Polyurethane prepolymers can be prepared by reacting glycol, 1,6-nucleic acid diol, and trimethylol glycol at a temperature of about 60 to 100 ° C. for 4 to 8 hours. The equivalence ratio between isocyanate and glycol is maintained at about 0.7 to 0.8 so that the intramolecular urethane structure is formed, and the hydroxy molecular structure comes to the end. At least one cyclohexanoic acid diisocyanate, isophorone diisocyanate, nucleomethylene diisocyanate or the like is preferably used during the reaction, and in the case of trimethylene oxide, neopentyl glycol, 1,6 nucleic acid diol and trimethylol glycol, trimethylene Preference is given to using at least one polyol comprising oxides. The content of trimethylene oxide is preferably used 2 to 10 parts by weight of the total polyurethane prepolymer content. If the trimethylene oxide compound is used in an amount less than 2 parts by weight, the scratch self-healing due to strong scratches is not only reduced, but also the chemical resistance is lowered. When the trimethylene oxide compound is used in an amount of more than 10 parts by weight, a problem may occur that may damage the elasticity of the urethane. have.

On the other hand, by including chitosan to react to prepare a polyester prepolymer (step S102). Preferably adipic acid, sebacic acid. Maleic acid and chitosan are reacted with ethylene-propylene block polyol to prepare a polyester prepolymer such that a hydroxyl group is present at the terminal.

In the step (S102), for example, adipic acid, sebacic acid, maleic acid, and chitosan are reacted with ethylene-propylene block polyol to prepare a polyester prepolymer of a long chain chain having an unsaturated group. When preparing the polyester prepolymer, the polymerization temperature of the polymerization reactor is maintained at 140-220 degrees to synthesize the condensation reaction for at least 8 hours. The content of chitosan to be used is preferably 1 to 5% by weight of the total polyester prepolymer content. If the chitosan content is less than 1%, scratch recovery is lowered. If it exceeds 5%, the processability and optical properties of the coating agent are deteriorated.

Next, 20 to 60 parts by weight of the polyurethane prepolymer prepared in step (S100) is mixed with respect to 100 parts by weight of the polyester prepolymer prepared in step (S012) to prepare a polyurethane-polyester hybrid resin (step S104) and to prepare a scratch self-healing coating according to the present invention by prescribing additives such as dispersants, leveling agents, viscosity regulators, etc. (step S106) in order to improve the processing performance of the coating agent and the physical properties at the surface and the interface.

On the other hand, in order to promote the reaction of the polyester prepolymer, metal catalysts such as acid catalysts and triphenyl phosphates may be used alone or in combination. The hydroxyl value of the prepared polyester prepolymer is preferably between 50 and 100 mg kOH / g. When the preparation of the polyester prepolymer is completed, the reactor temperature is lowered to 60 degrees to add a xylene solvent while maintaining a constant temperature to maintain a solid content of 50%. Thereafter, 20 to 60 parts by weight of the polyurethane prepolymer prepared above was slowly stirred into the reactor for about 1 hour with respect to 100 parts by weight of polyester prepolymer, thereby obtaining a hybridized viscous polyurethane-polyester compound. Thereafter, in order to improve the appearance and processing properties of the coating agent, a dispersant, a leveling agent, a viscosity regulator, and a crosslinking agent may be prescribed to obtain a coating agent having excellent scratch self-healing properties.

Hereinafter, embodiments for obtaining the polyurethane-polyester compound resin of the hybridized viscous form will be described in more detail.

Example 1

■ Preparation of Type 1 Polyurethane Prepolymers

140 g of isophorone diisocyanate, 18 g of trimethylene oxide, 120 g of ethylene propylene block polyol, 20 g of neopentyl glycol were placed in a xylene 120 g reactor and stirred for 8 hours while maintaining the temperature at 80 ° C. under a nitrogen atmosphere to have an intramolecular urethane structure. The hydroxy group was added to obtain a polyurethane prepolymer having a hydroxy value of 60 mg.KOH / g.

■ Preparation of Type 1 Polyester-Polyurethane Hybrid Resin

41 g of adipic acid, 18 g of maleic anhydride, 3.5 g of chitosan, 70 g of ethylene propylene block polyol, and 62 g of neopentyl glycol were added to the reactor and stirred for 1 hour while maintaining the temperature at 140 ° C., and then the reactor temperature was reached at 200 ° C. After the reaction was carried out until the acid value was maintained at 5 or less while maintaining the temperature, the mixture was cooled and the temperature was maintained at 60 ° C., while maintaining 50% solid content by adding xylene solvent, 20 to 60 parts by weight of the first type polyurethane prepolymer The mixture was stirred for about 1 hour in the reactor to prepare a polyester-polyurethane resin in a hybrid form.

The scratch porcelain of Example 1 was charged with 400 parts by weight of an isocyanate curing agent, 7 parts by weight of a leveling agent, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent based on 980 parts by weight of the first type polyester-polyurethane hybrid resin thus prepared. Prepare healing coatings.

[Example 2]

■ Preparation of Type 2 Polyurethane Prepolymers

50 g of cyclonucleic acid diisocyanate, 154 g of isophorone diisocyanate, 13 g of trimethylene oxides, and 40 g of 1,6-nucleic acid diols. Neopentylglycol 21g was put into a xylene 120g reactor and stirred for 8 hours while maintaining the temperature at 80 ° C under a nitrogen atmosphere to have an intramolecular urethane structure, and a hydroxyl group was formed at the end thereof to give a hydroxyl value of 65 mg.KOH / g. A polymer was obtained.

■ Preparation of Type 2 Polyester-Polyurethane Hybrid Resin

40 g of adipic acid, 17 g of maleic anhydride, 2.5 g of chitosan, 24 g of 1,6-nucleic acid diol, and 52 g of neopentylglycol were added to the reactor, followed by stirring for 1 hour while maintaining 140 ° C. Thereafter, the reactor temperature was raised to 200 ° C. and the reaction was carried out until the acid value was maintained at 5 or less, the temperature was cooled to 60 ° C., and 50% solid content was added to the xylene solvent to maintain the second type polyurethane prepolymer. 20 to 60 parts by weight and stirred in the reactor for about 1 hour to prepare a polyester-polyurethane resin in a hybrid form.

The scratch self-healing of Example 2 was carried out by adding 400 parts by weight of an isocyanate curing agent, 7 parts by weight of a leveling agent, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent to 980 parts by weight of the second type polyester-polyurethane hybrid resin thus prepared. Prepare a coating.

Example 3

400 parts by weight of isocyanate curing agent and leveling agent based on 500 parts by weight of the first type polyester-polyurethane hybrid resin and 980 parts by weight of the polyester-polyurethane hybrid resin mixed with 480 parts by weight of the second type polyester-polyurethane hybrid resin Part by weight, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent were prepared to prepare the scratch self-healing coating agent of Example 3.

Example 4

400 parts by weight of isocyanate curing agent and leveling agent based on 980 parts by weight of polyester-polyurethane hybrid resin mixed with 400 parts by weight of the first type polyester-polyurethane hybrid resin and 580 parts by weight of the second type polyester-polyurethane hybrid resin Part by weight, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent were prepared to prepare the scratch self-healing coating agent of Example 4.

Comparative Example 1

■ Preparation of Type 3 Polyurethane Prepolymers

120 g of isophorone diisocyanate, 22 g of 1,6-nucleic acid diols. 20 g of neopentyl glycol and 100 g of xylene were placed in a reactor and stirred for 8 hours while maintaining the temperature at 80 ° C. under a nitrogen atmosphere to obtain a polyurethane prepolymer.

■ Preparation of Third Type Polyester Polyurethane Hybrid Resin

41 g of adipic acid, 18 g of maleic anhydride, 70 g of ethylene propylene block polyol, and 62 g of neopentylglycol were added to the reactor, and the mixture was stirred at 140 ° C. for 1 hour. Thereafter, the reactor temperature was raised to 200 ° C. and the reaction was carried out until the acid value was maintained at 5 or less, followed by cooling to 60 ° C. to maintain 50% solids by adding xylene solvent, followed by 20 to 60 weight of the third type polyurethane prepolymer. The mixture was stirred in the reactor for about 1 hour to prepare a polyester-polyurethane resin in a hybrid form.

400 parts by weight of an isocyanate curing agent, 7 parts by weight of a leveling agent, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent were added to 980 parts by weight of the third type polyester-polyurethane resin of the hybridized form obtained by the above process. The scratch self-healing coating agent of Comparative Example 1 was prepared.

Comparative Example 2

■ Preparation of Type 4 Polyurethane Prepolymers

78 g of 1,6-nucleodiol diisocyanate, 14 g of propylene glycol, 20 g of neopentyl glycol and 100 g of xylene were added to a reactor and stirred for 8 hours while maintaining the temperature at 80 ° C. under a nitrogen atmosphere to obtain a polyurethane prepolymer.

■ Preparation of the fourth type polyester-polyurethane hybrid resin

30 g of adipic acid, 14 g of sebacic acid, 17 g of maleic anhydride, 70 g of ethylene propylene block polyol, and 62 g of neopentyl glycol were added to the reactor and stirred for 1 hour while maintaining the temperature at 140 ° C., and then the reactor temperature was raised to 200 ° C. While reacting until the acid value is maintained at 5 or less, and then cooled to 60 ° C. while maintaining 50% solids by adding xylene solvent, adding 4 type polyurethane prepolymer with 20 to 60 parts by weight and stirring in the reactor for about 1 hour. To prepare a polyester-polyurethane resin in a hybrid form.

400 parts by weight of an isocyanate curing agent, 7 parts by weight of a leveling agent, 13 parts by weight of a sunscreen stabilizer, and 550 parts by weight of a solvent were added to 980 parts by weight of the fourth type polyester-polyurethane resin of the hybridized form obtained by the above process. The scratch self-healing coating agent of Comparative Example 2 was prepared.

Comparative Example 3

400 parts by weight of isocyanate curing agent, 7 parts by weight of leveling agent, 13 parts by weight of sunscreen stabilizer, and a solvent based on 490 parts by weight of the third type polyester-polyurethane hybrid resin and 490 parts by weight of the fourth type polyester-polyurethane hybrid resin. 550 parts by weight was prepared to prepare a scratch self-healing coating agent of Comparative Example 3.

Preparation of Specimen

Mixing the compound obtained from the first to fourth examples and the first to third comparative examples and the additive for improving the physical properties of the coating agent and uniformly for 30 minutes using a dispersion stirring device with a composition as shown in Table 1 below The coating was prepared by mixing. The prepared coating agent was adjusted to a coating viscosity pod cup 12 seconds, sprayed onto a polycarbonate specimen at room temperature, and then dried and cured at 80 ° C. for 60 minutes to prepare specimens having a thickness of 20 μm.

Item Invention Comparative example Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Poly
Urethane-Poly
Ester Hybrid Resin First type
980 500 400 Second type
980 480 580 3rd type
980 490 4th type
980 490 Isocyanate
Hardener 400 400 400 400 400 400 400 Leveling agent 7 7 7 7 7 7 7 Sunscreen stabilizer 13 13 13 13 13 13 13 solvent 550 550 550 550 550 550 550

[Physical Measurement Evaluation]

The physical properties of each of the surface coating coating specimens obtained by Examples 1 to 4 and Comparative Examples 1 to 3 were measured, and the measurement results are shown in Table 2 below.

Item Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 scratch
Self-healing
○
○
○
○
△
△
△ Polish 92 92 91 92 91 92 92 Chemical resistance 250 ↑ 250 ↑ 250 ↑ 250 ↑ 100 92 125 Cosmetic resistance Good Good Good Good Swelling Swelling Swelling Weatherability Good Good Good Good crack crack crack

-Scratch resistance evaluation

Scratch resistance, such as scratch prevention, was subjected to linear reciprocating motion for 60 seconds with a 1kgf load with a metal brush, and the degree of scratches such as scratches on the surface was evaluated through microscopic observation. The degree was measured cross with a gloss tester.

-Scratch Natural Healing Assessment

In addition, the change in the surface glossiness sensitization, which appears as the restoration treatment of surface scratches, was measured cross. Gloss was measured using a glossmeter 60 °, and chemical resistance was measured more than 250 round trips by dropping methanol under 500g load on the pencil eraser. After washing for 24 hours, washed after washing. Weatherability was measured 2000 hours using a QUV tester. In addition, the adhesiveness with the base was measured by 2mmX-Cutting the specimen after leaving the specimen in an 80 × 80 ° C constant temperature humidifier for 48 hours.

1 is a flow chart showing the main process of the method for producing a scratch self-healing coating according to the present invention.

Claims (2)

(a) reacting the trimethylene oxide to produce a polyurethane prepolymer; (b) reacting to include chitosan to prepare a polyester prepolymer; And (c) mixing 20 to 60 parts by weight of the polyurethane prepolymer prepared in step (a) with respect to 100 parts by weight of the polyester prepolymer prepared in step (b); Method for preparing self-healing coating. A scratch self-healing coating prepared by the method of claim 1.

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