WO2017056141A1

WO2017056141A1 - Crosslinked coating film having scratch resistance and flexibility, and resin composition

Info

Publication number: WO2017056141A1
Application number: PCT/JP2015/077232
Authority: WO
Inventors: 亮介五十嵐; 堅二高野
Original assignee: 帝国インキ製造株式会社
Priority date: 2015-09-28
Filing date: 2015-09-28
Publication date: 2017-04-06
Also published as: CN108291113A; TW201712056A

Abstract

[Problem] To provide a crosslinked coating film which has excellent scratch resistance, high elongation properties, and suitability for pressure/vacuum forming, in-mold molding, etc. [Solution] A crosslinked coating film obtained by crosslinking a crosslinkable resin composition, characterized by having a glass transition temperature of -30 to 60°C,having storage moduli, as measured by a dynamic viscoelasticity test, of 0.1-1,000 MPa in the range of -30 to -10°C and of 0.01-5 MPa in the range of 80 to 150°C, and having a degree of elongation in a 25°C atmosphere of 30% or higher.

Description

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

The present invention relates to a car interior / exterior board and a plastic molded article surface, and relates to a crosslinked coating useful for moldability and scratch resistance, and a resin composition for forming the crosslinked coating.

Since plastic materials have excellent processability, they are molded into various shapes and widely used in many industrial fields as plastic molded products. However, plastic materials generally have a lower hardness than glass, metal, etc., and have a drawback that their surfaces are easily scratched. For this reason, various techniques for improving the above-described drawbacks have been developed by forming a coating film having excellent scratch resistance on the surface of a plastic molded product. In addition, even in a material having high hardness such as glass or metal, in a field where a high degree of design is required, a coating film having excellent scratch resistance may be formed like a plastic molded product. is there.

Conventionally, as a method for improving defects in a plastic molded product, as a method for imparting scratch resistance to the surface of the plastic molded product, an active energy ray-curable resin mainly composed of a polyfunctional acrylate such as dipentaerythritol hexaacrylate. A method of forming a hard coat film by applying the composition onto the surface of a plastic film and curing it with an active energy ray such as an ultraviolet ray or an electron beam has been practiced. This method is to improve the surface hardness and scratch resistance by increasing the crosslink density, but the hard coat film has a characteristic that the volumetric shrinkage of the paint film during curing tends to increase the internal strain. have.
As a result, once the coating film is scratched, peeling or cracking occurs from the site, and in some cases, the crack extends to the molded body itself. In addition, when secondary processing (film insert injection molding, in-mold molding) is performed, there is also a defect that cracks tend to occur because the stress during molding cannot be withstood.
Because of this problem, a scratch-resistant and flexible coating film, that is, compatibility between scratch resistance and flexibility (extension) is required.

In response to the problem of achieving both scratch resistance and flexibility, the coating film having flexibility and extensibility is a so-called self-healing rubber that recovers scratches on the surface over time. An elastic coating film is known.

For example, a coating film that combines flexibility and toughness, has excellent substrate adhesion, and self-repairs even if the coating film surface is damaged has been proposed. (See Patent Document 1) Further, a curable solvent-based paint containing a lipophilic polyrotaxane has been proposed as having a superior scratch resistance and chipping property and capable of forming a coating film in which cracks and the like are unlikely to occur. (Refer patent document 2) Moreover, the coating material which improved the coating-film hardness in the polyurethane-type soft coat and the restoring property of a coating film is also proposed. (See Patent Document 3)

However, there has been no cross-linked coating film that has an excellent balance of physical properties such as scratch resistance, flexibility, and blocking resistance, has high extensibility, and is suitable for compressed air / vacuum molding and in-mold molding.

JP 2012-121985 A JP 2010-43261 A JP 2006-328252 A

The present invention has been made in view of the above problems, and an object thereof is to provide a crosslinked coating film having excellent scratch resistance, high extensibility, and suitability for compressed air / vacuum molding and in-mold molding. is there. Another object of the present invention is to provide a crosslinked coating film having a so-called self-repairing property, in which the scratch disappears in a short time at room temperature or slight heating even when the scratch is attached.

In order to solve such problems and objects, the present invention developed by the present inventors is as follows.
(1) A crosslinked coating film obtained by crosslinking a crosslinkable resin composition,
The crosslinked coating film has a glass transition temperature of −30 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., 0.01 to 5 MPa in the range of 80 to 150 ° C.,
A cross-linked coating film characterized by having an elongation of 30% or more in an atmosphere at 25 ° C.

(2) The crosslinking method in the crosslinked coating film is one or more selected from urethane crosslinking, ene / thiol reaction crosslinking, cation crosslinking, radical polymerization crosslinking, and melamine crosslinking (1) The crosslinked coating film according to 1.
(3) The crosslinked coating film obtained by reacting the polyol (A) with the polyisocyanate compound (B), wherein the number average molecular weight (Mn) of the polyol (A) is 500 to 10,000. The hydroxyl value is 50 to 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. The crosslinked coating film according to (1) or (2), wherein the crosslinked coating film is 5.

(4) The crosslinked coating film according to any one of (1) to (3), wherein the crosslinked coating film has a haze value of 1.0% or less.
(5) A laminate comprising the crosslinked coating film according to any one of (1) to (4) and a base material, wherein the base material is polycarbonate resin, polyethylene terephthalate resin, ABS resin, polypropylene resin, imide A laminate having a crosslinked coating layer, which is formed of any one of resin, glass, and vinyl chloride resin, and wherein the crosslinked coating is applied to the substrate with a thickness of 300 μm or less.

(6) The glass transition temperature is −30 to 60 ° C., and the storage modulus in the dynamic viscoelasticity test is 0.1 to 1,000 MPa in the range of −30 to −10 ° C., and the range of 80 to 150 ° C. A crosslinkable resin composition that forms a cross-linked coating film having an elongation of 0.01 to 5 MPa and an elongation rate of 30% or more in an atmosphere of 25 ° C.,
The crosslinkable resin composition contains a polyol (A) and a polyisocyanate compound (B),
The polyol (A) has a number average molecular weight (Mn) of 500 to 10,000, a hydroxyl value of 50 to 250 (mmol / g),
A crosslinkable resin composition wherein the number of moles of isocyanate groups in the polyisocyanate compound (B) / number of moles of hydroxyl groups in the polyol (A) is 0.7 to 1.5.

According to the present invention, it is possible to provide a crosslinked coating film having excellent scratch resistance and high extensibility, which is suitable for vacuum forming or in-mold forming. In addition, since it is characterized by suppressing shrinkage due to crosslinking and increasing the crosslinking density, it has surprisingly high pencil hardness, good solvent resistance, and blocking resistance, A positioned crosslinked coating is obtained. Furthermore, even if a scratch is formed, a crosslinked coating film having a so-called self-healing performance in which the scratch disappears in a short time at room temperature or a little heating is obtained.

The glass transition temperature of the crosslinked coating film is preferably −30 to 60 ° C., more preferably −10 to 50 ° C. When the glass transition temperature of the crosslinked coating is less than −30 ° C., when the molded article having the crosslinked coating layer is packaged with a plastic film or the like, the contact portion of the plastic film is stuck on the crosslinked coating layer of the molded product. There is a possibility that it will be attached, and it tends to be inferior in terms of anti-blocking performance. Moreover, when the glass transition temperature of a coating film exceeds 60 degreeC, molecular motion performance falls and there exists a tendency for the damage | wound produced on the crosslinked coating-film layer surface to be hard to recover even if it applies heat.

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., the pressure 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., problems such as insufficient hardness and easy stickiness may occur. Although there is no restriction | limiting in particular about the upper limit of the storage elastic modulus in this temperature range, The value which a normal plastic can take is to about 1,000 MPa.
When it is less than 0.01 MPa in the range of 80 to 150 ° C., the rubber elasticity is too low and the scratches tend not to be recovered. If it exceeds 5 MPa, the crosslink density is too high and the elongation tends to decrease.

The elongation of the present invention is 30% or more, more preferably 100% or more in an atmosphere at 25 ° C. If it is less than 30%, it is close to the performance of a general hard coat treatment, and the characteristics as a 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 carrying. If the elongation is 30% or more, it is possible to obtain a crosslinked coating film that does not cause whitening and cracks in various molding processes such as compressed air / vacuum molding and injection molding.

Examples of the method for crosslinking the crosslinkable resin composition include urethane crosslinking, ene / thiol reaction crosslinking, cation crosslinking, radical polymerization crosslinking, and melamine crosslinking. Among these, urethane crosslinking, ene / thiol reaction crosslinking, and cationic crosslinking are preferable from the viewpoint of volumetric 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 rate and pot life. If it exceeds 10,000, the crosslink 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. If it is less than 50 mmol / g, the crosslinking density tends to decrease and the scratch resistance tends to decrease. If it exceeds 250 mmol / g, there may be a problem in handling in terms of reaction rate and pot life.

Examples of these polyols include bifunctional or higher functional polyols such as acrylic polyol, polycaprolactone diol, polycaprolactone triol, polycaprolactone tetraol, polycarbonate diol, polyester polyol, polyvinyl alcohol, cellulose resin, and polyvinyl butyral.

The number of moles of isocyanate groups in the polyisocyanate compound (B) / 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, Preferably, it is 1.0 to 1.2. When the NCO / OH ratio is less than 0.7, the scratch resistance and solvent resistance tend to decrease. On the other hand, if the NCO / OH ratio exceeds 1.5, the scratch resistance tends to decrease.

Examples of these polyisocyanates include hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylene diisocyanate, and low molecular polyol adducts of diphenylmethane diisocyanate.

Urethane crosslinking can be obtained by performing a thermosetting reaction of polyol and polyisocyanate compound in an atmosphere of 80 ° C. or more for 30 minutes or more.
When a polyol having a high hydroxyl value is used, the crosslinking reaction can be rapidly advanced by using a catalyst. As the type of catalyst, a normal curing catalyst such as a metal catalyst such as dibutyltin dilaurate or zinc naphthenate or an amine catalyst such as triethylenediamine or N-methylmorpholine can be used. By doing so, it becomes possible to improve the reaction rate, lower the reaction temperature, shorten the reaction time, and the like.
The addition amount of the curing catalyst is preferably 0.005 to 0.10% by mass with respect to the isocyanate-terminated urethane prepolymer. If it is less than 0.005% by mass, the effect of promoting the crosslinking reaction cannot be obtained, and if it exceeds 0.10% by mass, the pot life is hindered.
About the temperature in thermosetting reaction, a crosslinking reaction advances rapidly by setting reaction temperature higher than 80 degreeC.

Further, when the reaction temperature is set to 100 ° C. or higher, a blocked isocyanate obtained by modifying polyisocyanate with a blocking agent can also be used. The blocking agent blocks the isocyanate group of the polyisocyanate, thereby preventing reaction with active hydrogen groups such as moisture and hydroxyl groups and making it one-component. Further, the blocked polyisocyanate is a latent curing agent that reacts with an active hydrogen group when the blocking agent is dissociated by heating and the isocyanate group is activated again. The blocked isocyanate compound is not particularly limited as long as it is an isocyanate compound whose isocyanate group is protected with ε-caprolactam, MEK oxime, or the like. Specifically, the isocyanate group of the isocyanate compound is blocked with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, 3,5-dimethylpyrazole, diisopropylamine, diethyl malonate, ethyl acetoacetate, phenol, etc. Is mentioned.

The ene / thiol crosslinking is obtained by an ultraviolet curing reaction of a polymer diene compound and a trifunctional or higher functional low molecular thiol compound. As an example, such a polymer diene compound can be obtained by (meth) acryloyl-modifying the end of a polyol used in urethane crosslinking. However, even if it is another diene compound, the elasticity and elongation specified in the present invention are also obtained. If it is obtained, it is preferably used.

As an example, the cationic crosslinking is obtained by an ultraviolet curing reaction using a cationic polymerization initiator for an epoxy compound obtained by epoxidizing or oxetanylating the end of a polyol used in urethane crosslinking. Also, other compounds are preferably used as long as they can be cationically polymerized and can obtain the elasticity and elongation specified in the present invention.

When using a crosslinkable resin composition as a clear coating film, it is preferable that a haze value is 1.0% or less. When it is 1.0% or more, the use application is limited, and there is a possibility that it cannot be used from the viewpoint of optical product use and design. However, when a colored or matte coating film is required, the haze value may be adjusted to 1.0% or more using a coloring pigment, matting agent, extender pigment, brightening agent, or the like.
The matting agent and extender pigment are provided with anti-glare properties or blocking resistance by forming irregularities on the surface. As organic particles, styrene beads, acrylic beads, styrene-acrylic beads, melamine beads, benzoguanamine beads, Examples include polycarbonate beads, polyethylene beads, silicone beads, fluorine beads, vinylidene fluoride beads, polyvinyl chloride beads, epoxy beads, nylon beads, phenol beads, polyurethane beads, and the like. Inorganic particles include silica, talc, mica, kaolin, swellable fluoromica, montmorillonite, hectorite, calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, sodium silicate, aluminum hydroxide, iron oxide, oxidation Examples include zirconium, barium sulfate, and titanium oxide.
The amount of the matting agent and extender is 0.1 to 50 parts by mass with respect to 100 parts by mass of the crosslinkable composition.

Examples of the substrate to which the crosslinked coating film of the present invention can be applied include polycarbonate resin, polyethylene terephthalate resin, ABS resin, polypropylene resin, polyimide resin, glass, sapphire glass, polyvinyl chloride resin, and other substrates. Stainless steel, phosphate-treated steel, zinc steel, iron, copper, aluminum, brass, glass, acrylic resin, polyethylene naphthalate resin, polybutylene phthalate resin, polystyrene resin, AS resin, 6-nylon resin, 6,6- Nylon resin, MXD6 nylon resin, polyvinyl alcohol resin, polyurethane resin, phenol resin, melamine resin, polyacetal resin, chlorinated polyolefin resin, polyamide resin, polyether ether ketone resin, polyphenylene sulfide resin, NBR Fat, chloroprene resin, SBR resin, material in shaped substrates such as SEBS resins, such as those of their surface has been subjected to corona discharge treatment and resin coating treatment. In order to obtain adhesiveness to each, it is appropriately selected and adjusted by an appropriate crosslinking method, selection of an organic solvent, combined use of a coupling agent, and the like.

In addition, the crosslinked coating film obtained by the present invention is applied on the surface of the substrate by a known method such as spraying, brushing, dipping, printing, etc., and then heat-dried and / or active energy rays such as ultraviolet rays and electron beams. A crosslinked coating film is formed through the curing step.
Specifically, the film thickness of the formed cross-linked coating film is in the range of 1 μm to 300 μm. When a coating film of 100 μm or more is formed, the film is once applied to the substrate and subjected to a curing process, and then further overlapped. Application can be performed to obtain a desired film thickness. In the case of a thermosetting reaction, it may be performed at room temperature or may be heated. In the case of heating, it can be usually carried out at 40 to 200 ° C. for 1 to 300 minutes.

In the case of a curing reaction using active energy rays, infrared rays, ultraviolet rays, X rays, α rays, β rays, γ rays, electron beams, and the like can be used as the active energy rays to be irradiated. Among these, ultraviolet rays are most preferably used from the viewpoint of industrial properties such as safety and reaction efficiency. The wavelength of the ultraviolet rays used is preferably 200 to 400 nm, and preferable irradiation conditions are, for example, an illuminance of 1 to 1000 mW / cm ² and an integrated light quantity of 0.1 to 10000 mJ / cm ² . As an active energy ray irradiation device, for example, a lamp light source such as a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or an excimer lamp, a pulse such as an argon ion laser or a helium neon laser, a continuous laser light source, or an LED light source is used. It is possible.

The detailed reason why the coating film of the present invention exhibits a self-repairing function is not known, but by controlling the degree of crosslinking at the glass transition temperature of the present invention within the elastic modulus range of the present invention, a sea-island structure is formed in the resin film. This is thought to be due to the formation of It is estimated that this island structure is formed larger than before by highly crosslinking the coating film. Thus, it is considered that the tackiness of the sea structure in the conventional coating film is greatly suppressed, the slip property is exhibited, and the excellent elongation performance is obtained by the existing sea structure.

In addition, the coating film of the present invention has higher pencil hardness than the conventional self-repairing coating film, but the effect is presumed to be due to the above-described island structure.
Furthermore, the excellent solvent resistance obtained by the present invention can be obtained by highly crosslinking the degree of crosslinking at the glass transition temperature of the present invention within the elastic modulus range of the present invention.
Moreover, the urethane cross-linking of the present invention also has an effect of low shrinkage at the time of curing, which could not be predicted by the prior art.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Various characteristics were measured as follows.
(Glass transition temperature: Tg)
Using a differential scanning calorimeter (DSC), the temperature was measured from −50 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./min, and determined according to the provisions of JIS K7121.
(Storage modulus)
Using a rheometer, the storage elastic modulus (G ′) when dynamic viscoelasticity measurement was performed under the conditions of a sinusoidal frequency of 1 Hz and a temperature increase rate of 3 ° C./min from −30 ° C. to 150 ° C. was obtained.

(Adhesiveness)
In accordance with JIS K 5600-5-6 adhesion (cross-cut method), a coating film prepared on an ABS substrate was subjected to a cellophane peeling test using 25 1 mm squares. At this time, the number of grids adhered without peeling off the coating film was evaluated.
5: No peeling 4: Peeling within 5% 3: Peeling between 5% and less than 15% 2: Peeling between 15% and less than 35% 1: Peeling at 35% or more Passing level: 4 or more

(transparency)
The 10 μm coating film prepared on the glass substrate was peeled, and the haze value of the coating film was measured using an ultraviolet-visible spectrophotometer (V-570, manufactured by JASCO Corporation).
5: Less than 0.5% 4: 0.5% or more and less than 0.8% 3: 0.8% or more and less than 1.0% 2: 1.0% or more and less than 2.0% 1: 2.0% or more Pass level 3 or higher

(Solvent resistance)
A rubbing wear evaluation of 200 reciprocations with a load of 500 g was performed on a coating film prepared on an ABS base material using a nell that had been infiltrated with ethanol. The state of the coating film at this time was evaluated.
5: no trace 4: some swelling trace 3: some scar 2: large scar 1: substrate exposure pass level 4 or more

(Curl resistance)
The curl height at the four corners when placed on a horizontal surface was measured for a coating film prepared on a PET film substrate having a size of 10 cm × 10 cm and a thickness of 100 μm, and was determined according to the following criteria.
5: Less than 5 mm 4: 5 mm or more but less than 10 mm 3: 10 mm or more but less than 30 mm 2: 30 mm or more but less than 50 mm 1: 50 mm or more Passing level 3 or more

(Blocking resistance)
After the coating film prepared on the ABS base material is cut into 200 mm × 200 mm, a polycarbonate base material is overlaid on the coating film, and a load of 4 kg is further placed thereon, and after standing at 25 ° C. for 1 hour. The state when peeled was confirmed.
5: No blocking 4: Blocking slightly 3: Blocking to the extent that no force is required for peeling 2: Blocking to the extent that slightly force is required for peeling 1: Passing level of blocking to the extent that force is required for peeling 3 or more

(Elongation)
The 1 mm coating film created on the glass substrate was peeled, cut to 25 mm × 100 mm, and stretched using a universal tensile tester (Orientec STM-T-50BP). The elongation when it was torn was determined.
5: Elongation rate 100% or more 4: Elongation rate 50% or more and less than 100% 3: Elongation rate 30% or more and less than 50% 2: Elongation rate 5% or more and less than 30% 1: Elongation rate 5% or less Pass level 3 or more

(Abrasion resistance)
A rubbing wear evaluation of 20 reciprocations at a load of 500 g using a steel wool of # 0000 is applied to a coating film prepared on a polycarbonate substrate having a haze value of 1.0% and a thickness of 0.5 mm. went. The haze value of the coated material at this time was measured.
5: Haze value of the polycarbonate substrate + within 0.2% 4: Haze value of the polycarbonate substrate + 0.2% to less than 0.5% 3: Haze value of the polycarbonate substrate + 0.5% to 1.0 Less than% 2: Haze value of the polycarbonate substrate + 1.0% or more and less than 5.0% 1: Haze value of the polycarbonate substrate + 5.0% or more Pass level 3 or more

<Raw materials>
The following composition was used as the polyol (A) component.
A-1: Polycarbonate diol (Duranol T-5650E manufactured by Asahi Kasei Chemicals Corporation: molecular weight 500, hydroxyl value 225)
A-2: Polycarbonate diol (Duranol T-5562 manufactured by Asahi Kasei Chemicals Corporation: molecular weight 2000, hydroxyl value 56)
A-3: polycaprolactone triol (Praccel 308: molecular weight 850, hydroxyl value 195 manufactured by Daicel Corporation)
A-4: Acrylic polyol (varnish) (Excell PX41-11 made by Asia Chemical Industries, molecular weight 10,000, hydroxyl value 40)
A-5: acrylic polyol (varnish) (Asia Chemical Industrial Excell 450: molecular weight 11,000, hydroxyl value 24)

The composition shown below was used as an isocyanate compound (B) component.
B-1: XDI polyisocyanate (Takenate D-110N manufactured by Mitsui Chemicals, Inc.)
B-2: IPDI polyisocyanate (Duranate MHG-80B manufactured by Asahi Kasei Chemical Co., Ltd.)
B-3: HDI polyisocyanate (Duranate E402-80B manufactured by Asahi Kasei Chemical Co., Ltd.)
B-4: MDI-based polyisocyanate (BASF INOAC Polyuretan Corporation Lupranate M20S)

The following composition was used as the other component (C).
C-1: Urethane acrylate (Daicel Ornex Co., Ltd. EB
ECRYL8402)
C-2: Acrylate monomer (Kyoeisha Chemical Co., Ltd. Light acrylate DPE-6A)
C-3: Urethane-modified polyester resin (Byron U manufactured by Toyobo Co., Ltd.)
R-6100)
C-4: Cellulose acetate butyrate (EASTMAN CHEMI
CAB-381-0.5 manufactured by CAL)
C-5: Silica (MIZUKASIL P-5 manufactured by Mizusawa Chemical Co., Ltd.)
26)

The composition shown below was used as an additive (D) component.
D-1: Leveling agent (BYK-333 manufactured by BYK)
D-2: Photopolymerization initiator (Irgacure 184 manufactured by BASF)

Example 1
<Manufacture of crosslinkable resin composition>
60 parts by mass of polycarbonate diol (Duranor T-5650E manufactured by Asahi Kasei Chemicals Corporation), 39.5 parts by mass of ethylene glycol monobutyl ether acetate (butyl cellosolve acetate manufactured by Daishin Chemical Co., Ltd.), leveling agent (BYK-333 manufactured by BYK) 5 parts by mass and XD
88 parts by mass of I-based polyisocyanate (Takenate D-110N manufactured by Mitsui Chemicals, Inc.) was stirred and mixed to obtain a crosslinkable resin composition.
Next, the 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. It was.
However, for the elongation test, a coating film having a thickness of 1 mm was formed.
The obtained test pieces were evaluated as described above, and the test results are shown in Table 1.

(Examples 2 to 8)
In Example 1, the kind of crosslinkable resin composition and those contents were changed, and the crosslinked coating film was created. For Example 8, the drying was preliminarily dried at 60 ° C. for 5 minutes, and then irradiated with 800 mJ / cm ² with a high-pressure mercury lamp to form a coating film. The obtained test pieces were evaluated as described above, and the test results are shown in Table 1.

(Comparative Examples 1 to 3)
In Example 1, the kind of crosslinkable resin composition and those contents were changed, and the crosslinked coating film was created. For Comparative Example 3, the coating was preliminarily dried at 60 ° C. for 5 minutes and then irradiated with 800 mJ / cm ² with a high-pressure mercury lamp to form a coating film. About each obtained test piece, evaluation shown above was performed and the test result was shown in Table 1.

As shown in Table 1 below, the crosslinked coating films according to Examples 1 to 8 have both scratch resistance and elongation properties, and are excellent in various physical properties such as solvent resistance and curl resistance. Moreover, the anti-blocking property also has a relationship with the Tg of the coating film, and a tendency that the higher the Tg is, the better it is. For self-healing performance due to scratch resistance, if the Tg of the crosslinked coating is lower than the test temperature for scratch resistance, the scratches disappear immediately after the test, but the Tg of the crosslinked coating is higher than the test temperature for scratch resistance. In the test, the scratches disappeared by heating to a temperature at which the Tg of the crosslinked coating film was reached after the test.
In contrast, 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 elongation and curl resistance were significantly reduced.

Claims

A crosslinked coating film obtained by crosslinking a crosslinkable resin composition,
The crosslinked coating film has a glass transition temperature of −30 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., 0.01 to 5 MPa in the range of 80 to 150 ° C.,
A cross-linked coating film characterized by having an elongation of 30% or more in an atmosphere at 25 ° C.
The crosslinking method in the crosslinked coating film is one type or two or more types selected from urethane crosslinking, ene / thiol reaction crosslinking, cationic crosslinking, radical polymerization crosslinking, and melamine crosslinking. Cross-linked coating.
The crosslinked coating film is a crosslinked coating film obtained by reacting the polyol (A) and the polyisocyanate compound (B), and the number average molecular weight (Mn) of the polyol (A) is in the range of 500 to 10,000. Yes, the hydroxyl value is 50 to 250 (mmol / g), the number of moles of isocyanate group in the polyisocyanate compound (B) / the number of moles of hydroxyl group in the polyol (A) is 0.7 to 1.5. The crosslinked coating film according to claim 1 or 2, wherein
The crosslinked coating film according to any one of claims 1 to 3, wherein the crosslinked coating film is a clear coating film and has a haze value of 1.0% or less.
A laminate comprising the crosslinked coating film according to any one of claims 1 to 4 and a substrate, wherein the substrate is a polycarbonate resin, a polyethylene terephthalate resin, an ABS resin, a polypropylene resin, an imide resin, glass, chloride A laminate having a crosslinked coating layer, which is formed of any one of vinyl resins, and the crosslinked coating layer is applied to the substrate with a thickness of 300 μm or less.
The glass transition temperature is −30 to 60 ° C., and 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 is 0.00 in the range of 80 to 150 ° C. A crosslinkable resin composition that forms a crosslinked coating film having an elongation of from 30 to 30% in an atmosphere having an elongation of 25 ° C. of 01 to 5 MPa,
The crosslinkable resin composition contains a polyol (A) and a polyisocyanate compound (B),
The polyol (A) has a number average molecular weight (Mn) of 500 to 10,000, a hydroxyl value of 50 to 250 (mmol / g),
Number of moles of isocyanate group in the polyisocyanate compound (B) /
A crosslinkable resin composition wherein the number of moles of hydroxyl groups in the polyol (A) is 0.7 to 1.5.