CN108291113A - Crosslinking film and resin combination with marresistance and flexibility - Google Patents

Abstract

The project of the present invention is to provide a kind of excellent scratch resistance and extensibility is high, to the adaptable crosslinking film such as pressure sky, vacuum forming, in-molded.The solution that the present invention solves the above subject is a kind of crosslinking film, it is characterized in that, it is by being crosslinked film obtained by being crosslinked crosslinkable resin composition, the glass transition temperature of the crosslinking film is 30~60 DEG C, dynamic viscoelastic experiment in store elastic modulus 30~10 DEG C ranging from 0.1~1,000MPa, in 80~150 DEG C of ranging from 0.01~5MPa, and elongation is 30% or more under 25 DEG C of atmosphere.

Description

Cross-linked coating film having scratch resistance and flexibility, and resin composition

technical field

The present invention relates to interior and exterior decorative panels for automobiles and the surface of plastic molded products, to a crosslinked coating film useful for formability and scratch resistance, and to a resin composition for forming the crosslinked coating film.

Background technique

Since plastic materials have excellent processability, they are molded into various shapes and are widely used in various industrial fields as plastic molded products. However, in general, plastic materials have a lower hardness than glass, metal, etc., and have a disadvantage that scratches are easily generated on the surface. Therefore, various techniques have been developed to improve the above disadvantages by forming a coating film excellent in scratch resistance on the surface of plastic molded articles. In addition, even materials with high hardness such as glass and metal may form a coating film with excellent scratch resistance like plastic molded products in fields requiring a high level of designability.

Conventionally, as a method of improving the defects of plastic molded products, that is, a method of imparting scratch resistance to the surface of the plastic molded product, the following method has been implemented: the active energy of polyfunctional acrylate such as dipentaerythritol hexaacrylate as the main component The radiation-curable resin composition is coated on the surface of a plastic film and cured by active energy rays such as ultraviolet rays and electron rays to form a hard coating film. This method improves the surface hardness and scratch resistance by increasing the crosslinking density, but the hard coating film has a characteristic that the volume shrinkage of the coating film is large during curing and the internal strain tends to increase.

As a result, once the coating film is scratched, peeling and cracks occur from the site, and depending on the situation, the cracks may spread to the molded body itself. In addition, when secondary processing (film insert injection molding, in-mold molding) is performed, it cannot withstand the stress during molding and cracks are likely to occur.

According to this problem, a flexible coating film having excellent scratch resistance, that is, a balance between scratch resistance and flexibility (extensibility) is demanded.

In response to the problem of achieving both scratch resistance and flexibility, the so-called self-healing rubber is known as a soft and extensible coating film that recovers scratches generated on the surface over time. Elastic coating.

For example, a coating film has been proposed that has both flexibility and toughness, is excellent in substrate adhesion, and self-heals even if the coating film surface is scratched (see Patent Document 1). In addition, curable solvent-based paints containing lipophilic polyrotaxanes have been proposed as paints capable of forming a coating film that has excellent scratch resistance and chipping properties and is less prone to cracking (see Patent Document 2). In addition, paints having improved coating film hardness and coating film restorability in polyurethane-based soft coatings have also been proposed (see Patent Document 3).

However, there has been no cross-linked coating film with excellent balance of physical properties such as scratch resistance, flexibility, and blocking resistance, high elongation, and adaptability to air pressure, vacuum forming, and in-mold forming.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2012-121985

Patent Document 2: Japanese Patent Laid-Open No. 2010-43261

Patent Document 3: Japanese Patent Laid-Open No. 2006-328252

Contents of the invention

The problem to be solved by the invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a crosslinked coating film having excellent scratch resistance, high elongation, and adaptability to air pressure, vacuum forming, and in-mold forming. Furthermore, an object thereof is to provide a so-called self-healing crosslinked coating film having so-called self-healing properties such that even if scratched, the scratch disappears in a short time at room temperature or slightly heated.

method used to solve the problem

In order to solve such problems and objects, the present invention developed by the inventors of the present application is as follows.

(1) A crosslinked coating film, characterized in that it is a crosslinked coating film obtained by crosslinking a crosslinkable resin composition,

The glass transition temperature of the cross-linked coating film is -30～60°C,

The storage elastic modulus in the dynamic viscoelasticity test is 0.1 to 1,000 MPa in the range of -30°C to -10°C, and 0.01 to 5 MPa in the range of 80 to 150°C.

In addition, the elongation is 30% or more in an atmosphere of 25°C.

(2) The cross-linked coating film as described in (1), wherein the cross-linking method in the cross-linked coating film is selected from urethane cross-linking, ene/thiol reaction cross-linking, cationic cross-linking One or more of crosslinking, radical polymerization crosslinking, and melamine crosslinking.

(3) The cross-linked coating film as described in (1) or (2), wherein the cross-linked coating film is a cross-linked coating obtained by reacting polyol (A) and polyisocyanate compound (B). In the film, the number average molecular weight (Mn) of the polyol (A) is in the range of 500 to 10,000, the hydroxyl value is 50 to 250 (mmol/g), and the number of moles of isocyanate groups in the polyisocyanate compound (B)/polyol ( The number of moles of the hydroxyl group in A) is 0.7-1.5.

(4) The crosslinked coating film according to any one of (1) to (3), wherein the haze value of the crosslinked coating film is 1.0% or less.

(5) A laminated body, characterized in that it is a laminated body comprising the crosslinked coating film described in any one of (1) to (4) and a substrate, and the substrate is made of polycarbonate resin, Any one of polyethylene terephthalate resin, ABS resin, polypropylene resin, imide resin, glass, and vinyl chloride resin is formed, and the cross-linked coating film is coated on the surface with a thickness of 300 μm or less. on the above substrate.

(6) A crosslinkable resin composition, characterized in that it is a crosslinkable resin composition forming a crosslinked coating film, the glass transition temperature of the crosslinked coating film is -30 to 60°C, and the dynamic The storage elastic modulus in the viscoelasticity test is 0.1 to 1,000 MPa in the range of -30 to -10°C, and 0.01 to 5 MPa in the range of 80 to 150°C, and the elongation is 30% or more in the atmosphere of 25°C ,

This crosslinkable resin composition contains polyol (A) and polyisocyanate compound (B),

The number average molecular weight (Mn) of the polyol (A) is 500-10,000, the hydroxyl value is 50-250 (mmol/g),

The number of moles of isocyanate groups in the polyisocyanate compound (B)/the number of moles of hydroxyl groups in the polyol (A) is 0.7 to 1.5.

Invention effect

According to the present invention, it is possible to provide a crosslinked coating film having excellent scratch resistance, high elongation, and adaptability to vacuum forming and in-mold forming. In addition, since it is characterized by suppressing shrinkage due to crosslinking and increasing crosslinking density, it surprisingly has high pencil hardness, good solvent resistance, and anti-blocking properties, and can be positioned as moldable. Cross-linked coating film of hard coat material. Furthermore, even if scratched, it is possible to obtain a crosslinked coating film having so-called self-healing performance that the scratch disappears in a short time at room temperature or under slight heating.

Detailed ways

The glass transition temperature of the crosslinked coating film is preferably -30°C to 60°C, more preferably -10 to 50°C. When the glass transition temperature of the cross-linked coating film is lower than -30°C, when a molded product having a cross-linked coating film layer is packaged with a plastic film, etc., the contact portion of the plastic film may be attached to the cross-linked part of the molded product. Coated film layers tend to be poor in anti-blocking properties. In addition, when the glass transition temperature of the coating film exceeds 60° C., the molecular mobility decreases, and it tends to be difficult to restore the scratches formed on the surface of the crosslinked coating film layer by heating.

In addition, the storage elastic modulus in the dynamic viscoelasticity test is 0.1 to 1,000 MPa in the range of -30 to -10°C. In the range of 80 to 150°C, it is preferably 0.01 to 5 MPa, more preferably 0.1 to 2 MPa. If it is less than 0.1 MPa in the range of -30 to -10°C, there may be problems that the hardness cannot be obtained and stickiness is likely to occur. There is no particular limitation on the upper limit of the storage elastic modulus in this temperature range, but common plastics can obtain a value up to about 1,000 MPa.

When the temperature is less than 0.01 MPa in the range of 80 to 150° C., the rubber elasticity tends to be too low, and the scratches tend not to recover. When it exceeds 5 MPa, the crosslinking density tends to be too high and the elongation tends to decrease.

In addition, the elongation in the present invention is 30% or more, more preferably 100% or more, in an atmosphere at 25°C. When it is less than 30%, the performance of the general hard coat treatment is close, and the characteristics of the crosslinked coating film of the present invention cannot be obtained. When a coating film is formed on a flexible sheet, there is a possibility of cracking during handling. When the elongation is 30% or more, it is possible to form a crosslinked coating film that does not cause whitening or cracks during various molding processes such as compression molding, vacuum molding, and injection molding.

Examples of the method for crosslinking the crosslinkable resin composition include urethane crosslinking, ene/thiol reaction crosslinking, cationic crosslinking, radical polymerization crosslinking, and melamine crosslinking. Among them, urethane crosslinking, ene/thiol reaction crosslinking, and cationic crosslinking are preferable from the viewpoint of volume shrinkage of the coating film during curing.

When urethane crosslinking is selected, the number average molecular weight (Mn) of the polyol (A) is preferably in the range of 500 to 10,000, more preferably 500 to 5,000. When the number average molecular weight (Mn) is less than 500, there are problems of reaction speed and pot life. When it exceeds 10,000, the crosslinking density tends to decrease and the scratch resistance tends to decrease.

The hydroxyl value of the polyol (A) is preferably 50 mmol/g to 250 mmol/g, more preferably 100 mmol/g to 250 mmol/g. When it is less than 50 mmol/g, the crosslinking density tends to decrease and the scratch resistance tends to decrease. When it exceeds 250 mmol/g, there may be problems with handling in terms of reaction speed and pot life.

Examples of these polyols include acrylate polyol, polycaprolactone diol, polycaprolactone triol, polycaprolactone tetraol, polycarbonate diol, polyester polyol, polyvinyl alcohol , Cellulose-based resins, polyvinyl butyral and other bifunctional or higher polyols.

The number of moles of isocyanate groups in the polyisocyanate compound (B)/the number of moles of hydroxyl groups in the diol polymer (A) (hereinafter referred to as NCO/OH ratio) is preferably 0.7 to 1.5, more preferably 1.0 to 1.2 . When this NCO/OH ratio is less than 0.7, there exists a tendency for abrasion resistance and solvent resistance to fall. Moreover, when the NCO/OH ratio exceeds 1.5, there exists a tendency for abrasion resistance to fall.

Examples of these polyisocyanates include low-molecular-weight polyol adducts of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylylene isocyanate, and diphenylmethane diisocyanate.

The urethane crosslinking is obtained by subjecting a polyol and a polyisocyanate compound to a thermal curing reaction in an atmosphere of 80° C. or higher for 30 minutes or longer.

When a polyhydric alcohol with a high hydroxyl value is used, the crosslinking reaction can be rapidly advanced by using a catalyst. As the type of catalyst, metal-based catalysts such as dibutyltin dilaurate and zinc naphthenate, or general curing catalysts such as amine-based catalysts such as triethylenediamine and N-methylmorpholine, can be used. These catalysts can increase the reaction rate, lower the reaction temperature, shorten the reaction time, and the like.

It is preferable that the addition amount of a curing catalyst is 0.005-0.10 mass % by solid content ratio with respect to an isocyanate-terminated urethane prepolymer. If it is less than 0.005% by mass, the effect of accelerating the crosslinking reaction cannot be obtained, and if it exceeds 0.10% by mass, the pot life will be impaired.

Regarding the temperature in the thermosetting reaction, by setting the reaction temperature higher than 80° C., the crosslinking reaction proceeds rapidly.

Moreover, when the reaction temperature is 100 degreeC or more, the blocked isocyanate obtained by modifying polyisocyanate with a blocking agent can also be used. The blocking agent can block the isocyanate group of polyisocyanate to prevent the reaction with active hydrogen groups such as water and hydroxyl groups, and realize single liquefaction. Furthermore, the blocked polyisocyanate is a latent curing agent, and when heated, the blocking agent is dissociated, the isocyanate group is reactivated, and the active hydrogen group reacts. The blocked isocyanate compound is not particularly limited as long as the isocyanate group is protected by ε-caprolactone, MEK oxime, or the like. Specifically, ε-caprolactone, MEK oxime, cyclohexanone oxime, pyrazole, 3,5-dimethylpyrazole, diisopropylamine, diethyl malonate, ethyl acetoacetate, A compound in which the isocyanate group of the above-mentioned isocyanate compound is blocked, such as phenol, and the like.

The ene/thiol cross-linking is obtained by ultraviolet curing reaction between a polymer diene compound and a trifunctional or higher molecular weight thiol compound. Such a polymer diene compound, as an example, can be obtained by modifying the terminal of a polyol used in urethane crosslinking with a (meth)acryloyl group, but even other diene compounds, It can also be suitably used as long as the elasticity and elongation specified by this invention can be obtained.

Cationic crosslinking, as an example, is obtained by epoxidizing or oxetanylizing the terminals of polyols used in urethane crosslinking to obtain epoxy compounds, The epoxy compound is subjected to an ultraviolet curing reaction using a cationic polymerization initiator. Also, other compounds can be suitably used as long as cationic polymerization is possible and the elasticity and elongation specified in the present invention can be obtained.

When a crosslinkable resin composition is used as a clear coating film, the haze value is preferably 1.0% or less. When it is 1.0% or more, the application is limited, and there is a possibility that it cannot be used from the viewpoint of optical product application and design property. However, when a colored or matte coating film is required, it can be used after adjusting the haze value to 1.0% or more using a colored pigment, a matting agent, an extender, a glitter, or the like.

The matting agent and the extender pigment form unevenness on the surface to impart anti-glare or anti-blocking properties. Examples of organic particles include styrene beads, acrylic beads, styrene-acrylate beads, melamine beads, and benzoguanamine beads. , polycarbonate beads, polyethylene beads, silicone beads, fluorine beads, vinylidene fluoride beads, vinyl chloride beads, epoxy beads, nylon beads, phenol beads, polyurethane beads, etc. Examples of inorganic particles include silica, talc, mica, kaolin, swellable fluoromica, montmorillonite, hectorite, calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, sodium silicate, hydrogen Aluminum oxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, etc.

The compounding quantity of these matting agents and extender pigments is 0.1-50 mass parts with respect to 100 mass parts of crosslinkable compositions.

Examples of substrates to which the crosslinked coating film of the present invention can be applied include polycarbonate resins, polyethylene terephthalate resins, ABS resins, polypropylene resins, polyimide resins, glass, and sapphire glass. , polyvinyl chloride resin, etc., as other substrates, stainless steel, phosphate-treated steel, zinc steel, iron, copper, aluminum, brass, glass, acrylic resin, polyethylene naphthalate resin, polyethylene Butylene naphthalate resin, polystyrene resin, AS resin, 6-nylon resin, 6,6-nylon resin, MXD6 nylon resin, polyvinyl alcohol resin, polyurethane resin, phenolic resin, melamine resin, polyacetal resin, chlorinated polyolefin resin, polyamide resin, polyether ether ketone resin, polyphenylene sulfide resin, NBR resin, chloroprene resin, SBR resin, SEBS resin and other materials; Substrates with corona discharge treatment or resin coating treatment applied to the surface, etc. In order to obtain the adhesiveness with each base material, it can select and adjust suitably by an appropriate crosslinking method, selection of an organic solvent, combined use of a crosslinking agent, etc.

In addition, the crosslinked coating film obtained according to the present invention is coated on the substrate surface by known methods such as spraying, brushing, dipping, and printing, and then dried by heat and/or ultraviolet rays, electron rays, etc. The curing process by active energy rays forms a cross-linked coating film.

Specifically, the film thickness of the formed cross-linked coating film is in the range of 1 μm to 300 μm. When forming a coating film of 100 μm or more, the substrate can be coated and cured once, and then overcoated to obtain the obtained cross-linked coating film. desired film thickness. The thermosetting reaction may be performed at room temperature or may be heated. In the case of heating, it can usually be performed at 40 to 200° C. for 1 to 300 minutes.

When the curing reaction is performed by active energy rays, infrared rays, ultraviolet rays, X-rays, α rays, β rays, γ rays, electron rays, etc. can be used as the irradiated active energy rays. Among them, ultraviolet rays are most preferably used from industrial viewpoints such as safety and reaction efficiency. The wavelength of the ultraviolet rays to be used is preferably 200 to 400 nm, and preferred irradiation conditions are, for example, an illuminance of 1 to 1000 mW/cm ² and a cumulative light intensity of 0.1 to 10000 mJ/cm ² . As an irradiation device for active energy rays, for example, light sources such as high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and excimer lamps; pulsed or continuous laser light sources such as argon ion lasers and helium-neon lasers; LED light sources, etc. can be used.

The detailed reason why the coating film of the present invention exhibits the self-healing function has not yet been elucidated, but it is considered that by controlling the degree of crosslinking at the glass transition temperature of the present invention within the range of the elastic modulus of the present invention, the resin film can form an island structure. It is presumed that the island structure was formed larger than before by highly crosslinking the coating film. Accordingly, it is considered that the tackiness of the sea structure in the conventional coating film is greatly suppressed, lubricity is exhibited, and excellent elongation performance can be obtained due to the existing sea structure.

In addition, the coating film of the present invention can obtain higher hardness than conventional self-healing coating films in terms of pencil hardness, and this effect is presumed to be caused by the above-mentioned island structure.

Furthermore, the excellent solvent resistance obtained in the present invention is obtained by highly crosslinking the degree of crosslinking at the glass transition temperature of the present invention to the elastic modulus range of the present invention.

In addition, the urethane crosslinking of the present invention also has the effect of less shrinkage during curing, which was unexpected in the prior art.

Example

Hereafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

Each characteristic was measured as follows.

(Glass transition temperature: Tg)

Using a differential scanning calorimeter (DSC), it measures at -50 degreeC - 200 degreeC on conditions of a temperature increase rate of 10 degreeC/min, and obtain|requires based on the regulation of JISK7121.

(storage elastic modulus)

Using a rheometer, the dynamic viscoelasticity was measured at -30°C to 150°C under the conditions of a sinusoidal frequency of 1 Hz and a heating rate of 3°C/min, and the storage elastic modulus (G') at this time was obtained.

(adhesive)

For the coating film prepared on the ABS substrate, according to the method of JIS K 5600-5-6 adhesion (cross-section method), 25 cellophane tape peeling tests of 1 mm square were performed. At this time, the number of squares where the coating film adhered without peeling was evaluated.

5: No peeling

4: Peeling within 5%

3: more than 5% and less than 15% peeling off

2: More than 15% and less than 35% peeling off

1: More than 35% peeling off

Qualification standard 4 or above

(transparency)

The 10-micrometer coating film prepared on the glass base material was peeled off, and the haze value was measured using the ultraviolet-visible spectrophotometer (V-570 by JASCO Corporation) of this coating film.

5: Less than 0.5%

4: More than 0.5% and less than 0.8%

3: More than 0.8% and less than 1.0%

2: More than 1.0% and less than 2.0%

1: 2.0% or more

Qualified standard 3 or more

(solvent resistance)

With respect to the coating film prepared on the ABS base material, 200 reciprocating frictional wear evaluations were performed with a load of 500 g force using flannel soaked with ethanol. The state of the coating film at this time was evaluated.

5: no trace

4: There are some swelling marks

3: There are some scars

2: Large scars

1: The base material is exposed

Qualification standard 4 or above

(curl resistance)

For the coating film prepared on a PET film substrate with a thickness of 100 μm in a size of 10 cm×10 cm, the height of the curl at the four corners when placed on a horizontal plane was measured and judged based on the following criteria.

5: Less than 5mm

4: More than 5mm and less than 10mm

3: More than 10mm and less than 30mm

2: More than 30mm and less than 50mm

1: More than 50mm

Qualified standard 3 or more

(anti-blocking)

The coating film prepared on the ABS substrate was cut into 200mm×200mm, and the polycarbonate-based substrate was superimposed on the coating film, and a load of 4 kgf was placed on it, and after standing at 25°C for 1 hour, it was confirmed that The state at the time of stripping.

5: no adhesion

4: slightly sticky

3: Adhesion to the extent that no force is required for peeling

2: Adhesion to the extent that a little force is required for peeling

1: Adhesion to the extent that force is required for peeling

Qualified standard 3 or more

(extensibility)

The 1 mm coating film prepared on the glass substrate was peeled off, cut into 25 mm × 100 mm, and the coating film was elongated using a universal tensile testing machine (STM-T-50BP manufactured by Orientec Co., Ltd.) to obtain the elongation when the coating film was broken. Rate.

5: More than 100% elongation

4: The elongation is more than 50% and less than 100%

3: The elongation is more than 30% and less than 50%

2: The elongation is more than 5% and less than 30%

1: The elongation is less than 5%

Qualified standard 3 or more

(scratch resistance)

A coating film was prepared on a transparent polycarbonate substrate with a haze of 1.0% and a thickness of 0.5 mm. Using #0000 steel wool, the coating film was subjected to 20 round-trip friction and abrasion evaluations with a load of 500 grams. The haze value of the coating material at this time was measured.

5: The haze value of the polycarbonate substrate is within +0.2%

4: The haze value of the polycarbonate substrate is +0.2% or more and less than 0.5%

3: The haze value of the polycarbonate substrate is +0.5% or more and less than 1.0%

2: The haze value of the polycarbonate base material is +1.0% or more and less than 5.0%

1: The haze value of the polycarbonate base material is +5.0% or more

Qualified standard 3 or more

<Used raw materials>

As a polyol (A) component, the composition shown below was used.

· a-1: polycarbonate diol (DURANOL T-5650E manufactured by Asahi Kasei Chemical Co., Ltd.: molecular weight 500, hydroxyl value 225)

a-2: polycarbonate diol (DURANOL T-5652 manufactured by Asahi Kasei Chemical Co., Ltd.: molecular weight 2000, hydroxyl value 56)

a-3: polycaprolactone triol (PLACCEL 308 manufactured by Daicel Co., Ltd.: molecular weight 850, hydroxyl value 195)

a-4: Acrylic polyol (varnish) (Ekuseroru PX41-11 (Ekuseroru PX41-11, manufactured by Asia Chemical Industry Co., Ltd.): molecular weight 10,000, hydroxyl value 40)

・a-5: Acrylic ester polyol (varnish) (Ekuseroru 450 manufactured by Asia Chemical Industry Co., Ltd.: Molecular weight 11,000, hydroxyl value 24)

As an isocyanate compound (B) component, the composition shown below was used.

b-1: XDI-based polyisocyanate (TAKENATE D-110N manufactured by Mitsui Chemicals, Inc.)

b-2: IPDI-based polyisocyanate (DURANATE MHG-80B manufactured by Asahi Kasei Chemical Co., Ltd.)

b-3: HDI-based polyisocyanate (DURANATE E402-80B manufactured by Asahi Kasei Chemical Co., Ltd.)

b-4: MDI-based polyisocyanate (BASF INOAC Poly Urethane Co., Ltd. LUPRANATE M20S)

As other component (C)component, the composition shown below was used.

c-1: Urethane acrylate (EBECRYL8402 manufactured by Daicel-Allnex Corporation)

c-2: Acrylic ester monomer (Light Acrylate DPE-6A manufactured by Kyoeisha Chemical Co., Ltd.)

c-3: Urethane-modified polyester resin (VYLON UR-6100 manufactured by Toyobo Co., Ltd.)

c-4: Cellulose acetate butyrate (CAB-381-0.5 manufactured by EASTMAN CHEMICAL)

c-5: Silica (MIZUKASIL P-526 manufactured by Mizusawa Chemical Industry Co., Ltd.)

As an additive (D) component, the composition shown below was used.

d-l: leveling agent (BYK-333 manufactured by BYK company)

· d-2: Photopolymerization initiator (IRGACURE 184 manufactured by BASF Corporation)

(Example 1)

<Manufacture of cross-linkable resin composition>

60 parts by mass of polycarbonate diol (DURANOL T-5650E manufactured by Asahi Kasei Chemical Co., Ltd.), 39.5 parts by mass of ethylene glycol monobutyl ether acetate (butyl cellosolve acetate manufactured by Daishin Chemical Co., Ltd.), and leveled 0.5 parts by mass of agent (BYK-333 manufactured by BY K) and 88 parts by mass of XDI-based polyisocyanate (TAKENATE D-110N manufactured by Mitsui Chemicals, Inc.) were stirred and mixed to obtain a crosslinkable resin composition.

Next, the above-mentioned crosslinkable resin composition was applied to various substrates with a bar coater so that the film thickness after drying was 10 μm, and dried at 100° C. for 60 minutes to form a coating film. This was made into a test piece.

However, regarding the elongation test, a coating film having a film thickness of 1 mm was formed.

The obtained test pieces were evaluated as described above, and the experimental results are shown in Table 1.

Embodiment 2-8

In Example 1, the type and content of the crosslinkable resin composition were changed to prepare a crosslinked coating film. In Example 8, drying was pre-dried at 60° C. for 5 minutes, and then irradiated with a high-pressure mercury lamp at 800 mJ/cm ² to form a coating film. The above evaluations were performed on each of the obtained test pieces, and the test results are shown in Table 1.

Comparative example 1-3

In Example 1, the type and content of the crosslinkable resin composition were changed to prepare a crosslinked coating film. In Comparative Example 3, after drying was pre-dried at 60° C. for 5 minutes, 800 mJ/cm ² was irradiated with a high-pressure mercury lamp to form a coating film. The above evaluations were performed on each of the obtained test pieces, and the test results are shown in Table 1.

As shown in Table 1 below, the crosslinked coating films according to Examples 1 to 8 had both scratch resistance and elongation properties, and were excellent in various physical properties such as solvent resistance and curl resistance. In addition, blocking resistance is seen to be correlated with the Tg of the coating film, and it can be seen that the higher the Tg, the better it tends to be. Regarding the self-healing performance due to scratch resistance, when the Tg of the cross-linked coating film is lower than the test temperature for scratch resistance, the scratch disappears immediately after the test, and the Tg of the cross-linked coating film is higher than that of the scratch resistance In the case of a scratch test temperature, the scratches disappear by heating after the test to the temperature of Tg of the crosslinked coating film.

On the other hand, Comparative Example 1 was inferior in scratch resistance and solvent resistance. In Comparative Example 2, although the scratch resistance was good, the decrease in blocking resistance was remarkable. In Comparative Example 3, although the scratch resistance was good, the decrease in elongation and curl resistance was remarkable.

Table 1

Claims (6)

1. A crosslinked coating film, characterized in that it is a crosslinked coating film obtained by crosslinking a crosslinkable resin composition, The glass transition temperature of the cross-linked coating film is -30～60°C, The storage elastic modulus in the dynamic viscoelasticity test is 0.1 to 1,000 MPa in the range of -30 to -10 °C, and 0.01 to 5 MPa in the range of 80 to 150 °C. In addition, the elongation is 30% or more in an atmosphere of 25°C. 2. cross-linked coating film as claimed in claim 1, is characterized in that, the cross-linking method of described cross-linked coating film is selected from carbamate cross-linking, alkene/thiol reaction cross-linking, cationic cross-linking, One or more of radical polymerization crosslinking and melamine crosslinking. 3. the cross-linked coating film as claimed in claim 1 or 2, is characterized in that, described cross-linked coating film is the cross-linked coating film that makes polyol A and polyisocyanate compound B react, and the number of polyol A The average molecular weight Mn is in the range of 500 to 10,000, the hydroxyl value is 50 mmol/g to 250 mmol/g, and the number of moles of isocyanate groups in polyisocyanate compound B/number of moles of hydroxyl groups in polyol A is 0.7 to 1.5. 4. The cross-linked coating film according to any one of claims 1-3, characterized in that the cross-linked coating film is a transparent coating film with a haze value of 1.0% or less. 5. A laminated body with a crosslinked coating film layer, characterized in that it is a laminated body comprising the crosslinked coating film according to any one of claims 1 to 4 and a substrate, and the substrate is made of a polymer Carbonate resin, polyethylene terephthalate resin, ABS resin, polypropylene resin, imide resin, glass, vinyl chloride resin, and the cross-linked coating film has a thickness of 300 μm or less coated on the substrate. 6. A crosslinkable resin composition, characterized in that it is a crosslinkable resin composition forming a crosslinked coating film, The glass transition temperature of the cross-linked coating film is -30°C to 60°C, the storage elastic modulus in the dynamic viscoelasticity test is 0.1 to 1,000 MPa in the range of -30 to -10°C, and 0.1 to 1,000 MPa in the range of 80 to 150°C. The range is 0.01 ~ 5MPa, and the elongation is more than 30% in the atmosphere of 25 ℃, The crosslinkable resin composition comprises polyol A and polyisocyanate compound B, The number average molecular weight Mn of the polyol A is 500-10,000, the hydroxyl value is 50mmol/g-250mmol/g, The number of moles of the isocyanate group in the polyisocyanate compound B/the number of moles of the hydroxyl group in the polyol A is 0.7 to 1.5.