JPH05255462A - Composition - Google Patents

Abstract

PURPOSE:To obtain a composition comprising a polyfunctional monomer containing acryloyl and methacryloyl and a bifunctional monomer, providing a hard coat having excellent scratching resistance and wear resistance by coating the surface of a molded article of synthetic resin with the composition. CONSTITUTION:(A) 5-65 pts.wt. polyfunctional monomer [e.g. trimethylolpropane tri(meth)acrylate or urethane (meth)acrylate] containing three or more groups of acryloyl and methacryloyl is blended with (B) 5-30 pts.wt. bifunctional monomer (e.g. one of formula II or formula III) of formula I (R<1> is acryloyl or methacryloyl; R<2> is polyethylene oxide having 1,000-7,500 average molecular weight or random copolymer of ethylene oxide and propylene oxide; R<3> is H or methyl) in 100 pts.wt. total amounts to give the objective composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to particular compositions.
The composition provided by the present invention is preferably used for a hard coat or a cured coating film, and the formed hard coat or cured coating film has excellent antistatic property.

[0002]

2. Description of the Related Art Synthetic resins such as polymethylmethacrylate and polycarbonate are advantageous over glass in that they are easier to mold than glass and are inexpensive and lightweight. It is used in a wide range of applications such as optical disc substrates, optical components such as lenses and mirrors, decorative fields such as lighting and displays, and vehicle components such as automobiles.

However, since the synthetic resin molded article has insufficient scratch resistance and abrasion resistance, the surface may be scratched by contact with other objects during or after the molding process. Further, since the synthetic resin molded product has a high insulating property, energy generated by friction with another object is easily accumulated as static electricity and is hardly discharged. Therefore, fine dust easily adheres to the surface of the synthetic resin molded product, and the adhered dust is difficult to remove. If dust adheres to the surface of the synthetic resin molded product, not only the performance will deteriorate, but also the human body may be adversely affected, or electronic parts may be damaged or a fire may occur. Furthermore, since the surface of the above-mentioned synthetic resin molded product is hydrophobic, water tends to be condensed in high humidity, which may deteriorate the performance.

In order to solve the above problems, a method of applying an antistatic agent having a hydrophilic functional group such as a carboxyl group, a sulfonic acid group, a hydroxyl group or an ether bond to the surface of a synthetic resin molded article [conventional method] (1)], a method for forming a thin film by applying an antistatic agent containing the above-mentioned monomer having a hydrophilic functional group onto the surface of a synthetic resin molded article and then copolymerizing the same [conventional method (2)], 4 A method for forming a thin film made of an inorganic polymer by applying a solution containing a hydrolyzate or a partial hydrolyzate such as a functional silicon compound on the surface of a synthetic resin molded article and then curing the same [conventional method (3)]. Forming a thin film of a conductive ceramic such as tin oxide, indium oxide, zinc oxide, or indium-tin oxide on the surface of a synthetic resin molded product by a vacuum deposition method, or
Alternatively, a method of applying the antistatic agent containing the above-mentioned conductive ceramic [Conventional method (4)] is known.

In order to obtain a synthetic resin molded article having a high antistatic property by the conventional method (1), it is necessary to contain an antistatic agent in a high concentration in the coating film formed on the surface. Therefore, the scratch resistance and abrasion resistance of the coating film may decrease. Further, the antistatic agent may be deposited on the surface of the coating film, which may reduce the antistatic property.

In order to obtain a synthetic resin molded article having a high antistatic property by the conventional method (2), it is necessary to make the antistatic agent contain a monomer having a hydrophilic functional group at a high concentration. However, the scratch resistance and abrasion resistance of the coating film may decrease. Further, when an organic solvent is used in order to facilitate the preparation and application of the antistatic agent, it is necessary to sufficiently volatilize the organic solvent before copolymerization, resulting in low productivity.

The coating film formed on the surface of the synthetic resin molded product by the conventional method (3) has low adhesion to the synthetic resin molded product,
The peeling of the coating film may reduce the antistatic property. Further, when a solvent such as an aliphatic alcohol or an alkyl acetate is mixed with the solution to be applied, it is difficult to form a film having high hardness.

The conductive ceramic used in the conventional method (4) is inferior in transparency and has a problem that the synthetic resin molded product is colored. Further, when a film is formed by a vacuum vapor deposition method, there arises a problem that productivity becomes low, and when an antistatic agent is applied, it is difficult to uniformly disperse the conductive ceramic, and Since the light is scattered by the ceramic, there arises a problem that the surface of the synthetic resin molded product is fogged.

An object of the present invention is to provide a composition which gives a hard coat or a cured coating film having excellent antistatic property. Another object of the present invention is to apply a hard coat or a cured coating film having excellent scratch resistance, abrasion resistance, antistatic property and antifogging property by applying it to the surface of a synthetic resin molded article and then curing it. To provide a composition for forming.

[0010]

According to the present invention, the above object has three or more groups selected from the group consisting of an acryloyl group and a methacryloyl group (hereinafter, these are referred to as (meth) acryloyl groups). A polyfunctional monomer (A) and the following general formula (I)

[Chemical 2] [In the formula, R ¹ is a (meth) acryloyl group, R ² is both polyethylene oxide having an average molecular weight of 1000 to 7500, a random copolymer of ethylene oxide and propylene oxide, and a block copolymer of ethylene oxide and propylene oxide. It is a group selected from the group consisting of residues obtained by removing a hydroxyl group from the terminal, and R ³ is a hydrogen atom or a methyl group. ] It is achieved by providing the composition characterized by including the bifunctional monomer (B) shown by these.

Polyfunctional monomer constituting the composition of the present invention
Examples of (A) include trimethylolpropane tri
(Meth) acrylate, pentaerythritol tri (meth) acrylate
A) acrylate, pentaerythritol tetra (meth)
A) acrylate, pentaglycerol tri (meth) a
Acrylate, glycerin tri (meth) acrylate, di
Pentaerythritol tri (meth) acrylate, dipe
Intaerythritol tetra (meth) acrylate, dipe
Intaerythritol penta (meth) acrylate, dipe
Intaerythritol hexa (meth) acrylate, dipe
N-taerythritol hexa (meth) acrylate
(Meth) acrylate, 3 or more (meth) acrylates per molecule
Urethane (meth) acryl having an acryloyl group
For example, Where (meth) acrylate
Is a general term for acrylate and methacrylate. Many
As the functional monomer (A), two kinds of these monomers are used.
The above may be mixed and used. In addition, polyfunctional monomer
The content in the composition of (A) is 100 weight% of the composition.
It is important to set within the range of 5 to 65 parts by weight with respect to parts.
Excellent scratch and abrasion resistance for hard coats or cured coatings
Able to impart abrasion resistance, easy to apply, synthetic tree
Preferable from the viewpoint of high adhesion to oil molded products.
Yes.

More specific examples of the bifunctional monomer (B) constituting the composition of the present invention are as follows.

[Chemical 3] Here, R ² is polyethylene oxide having an average molecular weight of 1000 to 7500, a random copolymer of ethylene oxide and propylene oxide, or a residue obtained by removing a hydroxyl group from both ends of a block copolymer of ethylene oxide and propylene oxide. It is a group selected from the group consisting of In addition, the following general formula (I)

[Chemical 4] [Wherein, R ¹ is a (meth) acryloyl group, R ² is polyethylene oxide having an average molecular weight of 1000 to 7500, a random copolymer of ethylene oxide and propylene oxide, and a block copolymer of ethylene oxide and propylene oxide. R ³ is a group selected from the group consisting of a residue obtained by removing a hydroxyl group from both ends of
Is a hydrogen atom or a methyl group. ] The hard coat or cured coating film obtained by the composition in which the residual R ² of the bifunctional monomer (B) has an average molecular weight of less than 1000 is inferior in antistatic property and antifogging property, ^The hard coat or cured coating film obtained from the composition having an average molecular weight of ² of more than 7500 is inferior in antistatic property, antifogging property, scratch resistance and abrasion resistance. The average molecular weight of the residue R ² is more preferably 1500 to 3000. Further, when the residue R ² is a polyethylene glycol residue, the hard coat or cured coating film of the obtained composition is more antistatic and antifogging than when the residue R ² is a polypropylene glycol residue. It is preferable because it has excellent properties, scratch resistance, and abrasion resistance. When the residue R ² is a residue of a random copolymer or a block copolymer of ethylene oxide and propylene oxide, the residue R ²
The hard coat or cured coating film obtained from the composition having an ethylene oxide content of less than 20 weight percent is inferior in antistatic property, antifogging property, scratch resistance and abrasion resistance. The content of ethylene oxide in the residue R ² is preferably 40% by weight or more. Further, the composition obtained from the acryloyl compound is preferable because it has a higher curing rate than the composition obtained from the methacryloyl compound. As the monomer (B), two or more kinds of the above monomers may be mixed and used. The content of the monomer (B) in the composition may be set in the range of 5 to 30 parts by weight relative to 100 parts by weight of the composition so that the hard coat or the cured coating film has excellent antistatic property and antifogging property. Is preferable from the standpoints of imparting durability, scratch resistance and abrasion resistance, and obtaining high adhesion to synthetic resin molded products.

When the composition of the present invention is used as a composition for hard coat or cured coating film, N-vinyl-2-
Pyrrolidone, tetrahydrofurfuryl (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate, morpholine (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2- Ethylhexyl (meta)
Polymerizable monomers such as acrylate, ethylene oxide modified bisphenol A diacrylate, ethylene oxide modified bisphenol F diacrylate, or
A mixture of non-polymerizable solvents such as benzene, toluene, isopropyl alcohol, isobutyl alcohol, methyl ethyl ketone, and ethyl cellosolve facilitates coating work, has a uniform thickness, and is a synthetic resin molded product. It is preferable from the standpoint that a hard coat or a cured coating film having high adhesion with is obtained. Here, the content of these polymerizable monomers in the composition is the composition 1
50 parts by weight or less relative to 00 parts by weight, and the content of the non-polymerizable solvent in the composition should be 200 parts by weight or less so that the scratch resistance of the hard coat or cured coating film And it is preferable in that the abrasion resistance is not lowered. When using a non-polymerizable solvent, it is necessary to remove the non-polymerizable solvent by performing a treatment such as room temperature drying, warm air drying or infrared irradiation before curing the composition. It is preferable because the scratch resistance and abrasion resistance of the cured coating film are not deteriorated.

As a method for applying the composition of the present invention to the surface of a synthetic resin molded article, a method such as a spin coating method, a brush coating method, a dip coating method, a spray coating method, a flow coating method and a bar coating method is adopted. To be done. It is preferable to employ the spin coating method, the dip coating method or the bar coating method because the coating work is easy and a film having a uniform thickness and a smooth film can be obtained.

When the hard coat layer or the cured coating film has a thickness in the range of 1 to 30 μm, it has sufficient scratch resistance and abrasion resistance and cracks inside. It is preferable in that a hard coat or a cured coating film with less occurrence of is obtained. Further, it is more preferable to apply the hard coat or the cured coating so that the thickness thereof is in the range of 3 to 15 μm. In order to obtain a hard coat or a cured coating film having a thickness in the range of 1 to 30 μm, it is preferred to prepare and use the composition so that the viscosity at 20 ° C. is in the range of 5 to 1000 centipoise.

The method of curing the composition of the present invention includes:
The method of irradiating with ultraviolet rays is preferable from the viewpoint of obtaining high productivity. The wavelength of ultraviolet rays is preferably in the range of 100 to 500 nm. It is preferable to use ultraviolet rays emitted from a high-pressure mercury lamp or a metal halide lamp for curing because the above composition can be efficiently cured in a nitrogen gas, an inert gas such as an argon gas, or in the atmosphere.

When the composition of the present invention is cured by irradiation with ultraviolet rays, it is preferable that a photopolymerization initiator is mixed in the composition. Suitable photopolymerization initiators include 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-t-
Acetophenones such as butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -Based photopolymerization initiators, benzoin methyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, and other benzoin-based photopolymerization initiators, benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-
Benzophenone-based photopolymerization initiators such as 4′-methyldiphenyl sulfide, thioxanthones such as thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, and 2,4-diethylthioxanthone A photopolymerization initiator or the like is used. The content of the photopolymerization initiator in the composition should be adjusted to 10 parts by weight or less with respect to 100 parts by weight of the composition so that the scratch resistance and abrasion resistance of the hard coat or the cured coating film can be improved. Is preferable because it does not decrease.

As a synthetic resin molded article on which a hard coat or a cured coating film formed from the composition of the present invention is formed, injection molding made of polymethylmethacrylate resin, polycarbonate resin, polystyrene resin, polyvinyl chloride resin, ABS resin or the like. Products, sheet-shaped molded products or film-shaped molded products. In particular, molded products made of polymethylmethacrylate resin or polycarbonate resin are used in fields utilizing their optical or mechanical properties, and are required to have high performance in scratch resistance, abrasion resistance, antistatic property and antifogging property. In many cases, it is preferable to form a hard coat or a cured coating film on the surface by using the composition of the present invention.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples. The evaluation methods in the examples are as follows.

1. Scratch resistance and abrasion resistance (1) Hardness test ... JIS K 5400-197
Pencil scratch test specified in 9. (2) Abrasion test ... JIS K 7204-197
7 is a wear test using a tester specified in No. 7, and the change amount of reflectance after 100 rotations with a load of 250 g applied to the wear wheel CS-10 was measured using He-Ne laser light. Shows the value (%) obtained by the following formula. {(Reflectance before abrasion test)-(Reflectance after abrasion test)}
/ (Reflectance before abrasion test) x 100 (3) Scratch test ...- Mounting # 0000 steel wool on a 30 mm square metal rod and applying a load of 900 g to the coating film surface 50 reciprocations After making it, haze meter (manufactured by Japan Precision Optical Co., Ltd., SEP-HS-30D
Type) is used to measure the increase in haze value before and after the scratch test, and this is expressed as a percentage. Here, the moving speed when the metal rod is reciprocated is 10 mm / sec, and the moving distance is 70 mm. (4) Adhesion test: Using a cutter knife, cuts that reach the synthetic resin molded product are provided at 11-mm intervals in 11 rows and 11 rows, and a total of 100 substrates are made. After sticking cellophane tape on it, peel it off abruptly and count the number of bases on which the coating film has peeled off. The criteria for judgment are as follows. ○ ・ ・ ・ ・ When there are 0 bases from which the coating has peeled △ ・ ・ ・ ・ When 1 to 50 bases from which the coating has peeled × ・ ・ ・ ・ ・ ・ 51 bases from which the coating has peeled ~ 100 cases 2. Antistatic property (1) Half-life measurement: The half-life (seconds) of the generated charged potential is measured using a static Honest meter manufactured by Shishido Electrostatic Co., Ltd. The measurement is performed under conditions of an applied voltage of 8 kV and an application time of 30 seconds under a constant temperature and humidity of 20 ° C. and 50% humidity. (2) Surface resistivity measurement ... The surface resistance value (Ω) is measured using a super insulation resistance / micro ammeter TR-8601 and a measurement sample box TR-42 manufactured by Advantest Corporation.
The measurement is carried out under the conditions of an applied voltage of 100 V and an applied time of 1 minute under a constant temperature and humidity of 20 ° C. and a humidity of 50%. 3. Anti-fog property Anti-fog property test: After allowing the test piece to stand at 0 ° C for 30 minutes, it is moved to a constant temperature and humidity of 20 ° C and a humidity of 60% and the state of dew condensation is observed. The criteria for judgment are as follows. ○ ・ ・ ・ ・ No condensation. △ ... ・ Slightly condensed. × ・ ・ ・ ・ Condensation is severe. 4. Durability High temperature / humidity test: The test piece is left for 1000 hours under constant temperature and humidity at a temperature of 80 ° C. and a humidity of 85%, and then the appearance is observed. The criteria for judgment are as follows. ○ ・ ・ ・ ・ No change in appearance. Δ: slight clouding and unevenness are observed. × ... ・ Rainy cloudiness and unevenness are observed.

The monomers, non-polymerizable solvents and photopolymerization initiators constituting the composition are shown by the following abbreviations. Monomer PE-4A: Pentaerythritol tetraacrylate PE-3A: Pentaerythritol triacrylate

[Chemical 5] [Here, A is a residue obtained by removing a hydroxyl group from both ends of a random copolymer of 50 parts by weight of ethylene oxide and 50 parts by weight of propylene oxide having an average molecular weight of 3500. ]

[Chemical 6] [Here, A is a residue obtained by removing a hydroxyl group from both ends of a block copolymer having 75 parts by weight of ethylene oxide having an average molecular weight of 5000 and 25 parts by weight of propylene oxide. ] THF-A: tetrahydrofurfuryl acrylate NVP: N-vinyl-2-pyrrolidone non-polymerizable solvent EC: ethyl cellosolve photopolymerization initiator HCHPK: 1-hydroxycyclohexyl phenyl ketone

Examples 1 to 5 and Comparative Examples 1 to 5 The resin compositions shown in Table 1 were prepared, and a methacrylic resin plate having a thickness of 2 mm (Kuraray Co., Ltd., trade name Paragrass) was spin-coated. It was applied by. Then, using a high-pressure mercury lamp having an intensity of 120 W / cm on the coated surface, ultraviolet rays were irradiated at a irradiation distance of 15 cm in the atmosphere.
Irradiation was carried out for 0 seconds to form a cured coating film. The results of various evaluation tests performed on the obtained cured coating film are also shown in Table 1.

[Table 1] As is clear from Table 1, the cured coating films obtained from the compositions of the present invention in Examples 1 to 5 are excellent in scratch resistance, abrasion resistance, antistatic property and antifogging property,
Moreover, it is understood that these performances are maintained even after the exposure test under high temperature and high humidity. On the other hand, the average molecular weight of the group R ² in the monomer (B) is 1
The cured coating films of Comparative Examples 1 and 2 obtained from compositions of less than 000 are inferior in antistatic property and antifogging property,
The average molecular weight of the group R ² in the monomer (B) is 7500
The cured coating film of Comparative Example 3 obtained with the larger composition was inferior in scratch resistance, abrasion resistance, adhesion and durability under high temperature and high humidity. Moreover, among the compositions of the present invention, Comparative Example 4 obtained from a composition to which the monomer (B) was not added
The cured coating film of No. 1 is inferior in antistatic property and antifogging property, and in Comparative Example 5 in which the composition of the present invention is not applied as a cured coating film, it is excellent in all of scratch resistance, abrasion resistance, antistatic property and antifogging property. I was taking it.

[0023]

INDUSTRIAL APPLICABILITY According to the present invention, a composition which provides a hard coat or a cured coating film having excellent antistatic property is provided. Further, according to the present invention, a hard coat or a cured coating film having excellent scratch resistance, abrasion resistance, antistatic property and antifogging property is formed by applying it on the surface of a synthetic resin molded article and then curing it. A composition is provided.

Claims (1)

[Claims] 1. A polyfunctional monomer (A) having three or more groups selected from the group consisting of an acryloyl group and a methacryloyl group, and the following general formula (I): [In the formula, R ¹ is an acryloyl group or a methacryloyl group, R ² is polyethylene oxide having an average molecular weight of 1000 to 7500, a random copolymer of ethylene oxide and propylene oxide, and a block copolymer of ethylene oxide and propylene oxide. R ³ is a group selected from the group consisting of a residue obtained by removing a hydroxyl group from both ends, and R ³ is a hydrogen atom or a methyl group. ] The bifunctional monomer (B) shown by these, and the composition characterized by the above-mentioned.