JPH04175385A - Method for preparation of hard coat with excellent resistance to scuffing and coating composition - Google Patents

Abstract

PURPOSE:To obtain a hard coat with excellent resistance to scuffing by using a specified compsn. for each of an undercoat and a successive topcoat. CONSTITUTION:A transparent base sheet is under-coated with a compsn. I and is then top-coated with a compsn. II. The compsn. I is a compsn. which consists of a copolymer of the total of 100 pts.wt. consisting of 60-90 pts.wt. at least one of methyl acrylate, ethyl acrylate, etc., and 10-40 pts.wt. at least one of hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, etc., and an org. solvent. The compsn. II is a compsn. with a solid content of 20-30% which consists of a component with the total of 100 pts.wt. consisting of a hydrolyzate and a partial condensate (a) of 75-85 pts.wt. alkoxysilane compd. with a compsn. wherein the molar ratio of R<1> Si(OR<2>)3 to Si(OR<3>)4 (wherein R<1>-R<3> are each a methyl group, etc.,) is 7:3-10:0, 10-20 pts.wt. organosilica sol (b) wherein SiO2 powder is dispersed in an org. solvent and the content is 20-40wt.%, 1-8 pts.wt. copolymer (c) of the compsn. I, 0.5-1.5 pts.wt. epoxy resin (d) having 2 or more epoxy groups and 0.3-1 pt.wt. curing catalyst and an org. solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a hard coat with excellent scratch resistance and a coating composition used in the method.

Prior art and its problems In general, when a hard coat is provided to impart scratch resistance to an infrared absorption filter or the like, a one-component or two-component hard coat has been conventionally used.

However, with a corrugated hard coat, increasing its surface hardness reduces its adhesion to the support, and with a two-component hard coat, increasing its adhesion reduces its surface hardness. There is.

Means for Solving the Problems As a result of intensive research in view of the above-mentioned problems of the prior art, the present inventor coated a coating composition with a high solid content divided into two layers: an undercoat and an overcoat. It has been found that by doing so, scratch resistance can be imparted to the support and the adhesion of the coated film is improved.

That is, the present invention provides the following hard coat manufacturing method and coating composition with excellent scratch resistance.

■60 to 90 parts by weight of at least one ester selected from methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxymethyl methacrylate, hydroxy selected from the group consisting of ethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid, a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid. Solid content: 5-1 consisting of a copolymer consisting of 10-40 parts by weight of at least one type, 100 parts by weight in total, and an organic solvent
5% of Coating Composition I was coated on a transparent resin substrate as an undercoat, and on top of that,
(a) R' Si (OR2)3 and S i (OR3)
4 (However, R1 is a methyl group, ethyl group or propyl group, R2 is a methyl group, ethyl group or propyl group, R3
is a hydrolyzate and partial condensate of 75 to 85 parts by weight of an alkoxysilane compound having a molar ratio of 7=3 to 10:0 with respect to methyl, ethyl, or propyl groups; (b) SiO2 powder is an organic Organosilica sol 10~ dispersed in a solvent and having a content of 20~40% by weight
20 parts by weight, (c) 60 to 90 parts by weight of at least one selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate. , hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid, a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid. A total of 10 to 40 parts by weight of at least one selected from the group 1
(d) 0.5 to 8 parts by weight of a copolymer consisting of 0.00 parts by weight, (d) an epoxy resin having two or more epoxy groups;
Solid content consisting of 1.5 parts by weight and (e) 0.3 to 1 part by weight of curing catalyst, a total of 100 parts by weight, and an organic solvent.
A method for producing a hard coat with excellent scratch resistance, characterized by coating with 0% coating composition II as an overcoat.

■ 60 to 90 parts by weight of at least one ester selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate,
Hydroxypropyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, compounds with an amide group of acrylic acid, compounds with a nitrile group of acrylic acid, compounds with an amide group of methacrylic acid, and compounds with a nitrile group of methacrylic acid A total of 100M of 10 to 40 parts by weight of at least one selected from the group consisting of compounds
Coating for use as an undercoat in the method for producing a hard coat with excellent scratch resistance as described in item 1 above, characterized in that it is made of a copolymer consisting of 50% to 100% and an organic solvent, and has a solid content of 5 to 15%. Composition.

■(a) R' S i (OR2)3 and S i (OR
3) 4 (However, R1 is a methyl group, ethyl group or propyl group, R2 is a methyl group, ethyl group or propyl group,
(b) SiO powder is dispersed in an organic solvent and the content is 20 to 40% by weight.
20 parts by weight, (c) 60 to 90 parts by weight of at least one selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate. , hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid, a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid. A total of 10 to 40 parts by weight of at least one selected from the group 1
(d) 0.5 to 8 parts by weight of a copolymer consisting of 0.00 parts by weight, (d) an epoxy resin having two or more epoxy groups;
1.5 parts by weight and (e) curing catalyst 0.3 to 1 part by weight, totaling 100 parts by weight, and an organic solvent, and the solid content thereof is 20 to 30%. A coating composition used for an overcoat in a hard coat manufacturing method with excellent scratch resistance.

The present invention will be explained in detail below.

First, in the production of coating composition I, a copolymer used therein is synthesized. This includes 60 to 90 parts by weight of at least one ester selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxymethyl methacrylate. , hydroxyethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid,
At least 10 to 40 parts by weight of at least one selected from the group consisting of a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid, making up a total of 100 parts by weight. After adding a polymerization regulator in an organic solvent, a polymerization initiator is added in the presence of nitrogen gas to carry out polymerization.

The above copolymer has a solid content of 30 to 40% and a viscosity of 5.
It is preferable to set it as 00-3000cps (30 degreeC).

Next, an organic solvent is further added to the obtained copolymer to adjust the solid content to 5 to 15%, and the resulting copolymer is used as coating composition I.

As the organic solvent, known organic solvents can be used, such as ketones such as acetone, methyl acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, butylone, methyl amyl ketone, and methyl butyl ketone, methyl ether, ethyl ether, and isopropyl ether. , ethers such as methyl cellosolve, methyl carpitol, anisole, tetraethylene glycol dimethyl ether, propylene oxide, dioxane, tetrahydrofuran, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, tertiary amyl alcohol, n-octyl alcohol, Examples include alcohols such as ethylene glycol, benzyl alcohol, cyclohexanol, and tetrahydrofurfuryl alcohol.

As a method for producing coating composition (1), first, Si
An organosilica sol in which O2 powder is dispersed in an organic solvent to have a content of 20 to 40% by weight is used. It is preferable to use Si02 powder having a particle size of 5 to 30 μm. Also, specific examples of organic solvents that can be used here include methanol, ethanol, isopropanol,
Examples include n-propanol, n-butanol, methyl ethyl ketone, and toluene.

Next, an alkoxysilane compound is added to this, and hydrolysis is carried out by mixing and stirring in an acidic aqueous solution such as hydrochloric acid at about 20 to 30°C for about 45 minutes.
By stirring at a temperature of about 3 hours, a partial condensate of the alkoxysilane compound can be obtained. The alkoxysilane compound mentioned above includes R' Si (OR2)3 and S
i (OR3)4 (However, R' is a methyl group, ethyl group or propyl group, R2 is a methyl group, ethyl group or propyl group, R3 is a methyl group, ethyl group or propyl group)
A mixture of alkoxysilane compounds having a molar ratio of 7:3 to 10:0 is used.

Next, the copolymer of coating composition (1) is synthesized by a conventional method. This is at least one ester selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate.
90 parts i, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, compounds having an amide group of acrylic acid, compounds having a nitrile group of acrylic acid, methacrylic acid At least one selected from the group consisting of a compound having an amide group and a compound having a nitrile group of methacrylic acid.
A total of 100 parts by weight of 40 parts by weight can be obtained by the same synthesis method as for the copolymer of coating composition (1).

Coating composition II is obtained by mixing the obtained copolymer and the above alkoxysilane compound together with an epoxy resin having two or more epoxy groups and a curing catalyst in an acidic aqueous solution such as acetic acid and stirring. The above copolymer has a solid content of 30 to 40% and a viscosity of 5000 to 20%.
It is preferable to use the temperature as 000Cps (30°C).

Further, the above-mentioned epoxy resin is not particularly limited as long as it has two or more epoxy groups, and any known resin can be used. Specific examples of the curing catalyst include epoxy curing catalysts and alkali catalysts such as sodium acetate, caustic soda, amines, and alcohol amines.

These contents range from 75 to 85 alkoxysilane compounds.
10 to 20 parts by weight of organosilica sol, 1 to 8 parts by weight of the above copolymer, and 0.5 to 1.0 parts by weight of epoxy resin.
5 parts by weight and 0.3 to 1 part by weight of the above curing catalyst to make a total of 100 parts by weight, and an organic solvent was added to make the solid content 20 to 30%, preferably 23 to 27%. Coating composition ■. The above organic solvent is
Those similar to those used in coating composition I can be used.

Coating compositions I and II obtained as described above are coated on a transparent resin substrate according to a conventional method. As the transparent resin substrate used in the present invention, known resins such as acrylic resin, methacrylic resin, and polycarbonate resin can be used.

First, 0.0% coating composition (2) was applied onto a transparent resin substrate.
Coating with a film thickness of 5-1.5 μm, 60-10 μm
Dry and harden at about 0°C for about 10 to 60 minutes. Furthermore, coating composition II was coated to a thickness of 3 to 6 μm, and dried at about 80 to 120°C for about 1 to 2 hours.
By curing, the hard coat of the present invention is obtained.

Effects of the Invention According to the hard coat manufacturing method and coating composition with excellent scratch resistance of the present invention, scratch resistance can be imparted to the support by using a coating composition with a high solid content. It also improves the adhesion between the support and the coating film, and eliminates bubbles (bubbles, etc.).
An excellent hard coat with few coating defects such as small protrusions etc. can be obtained.

EXAMPLES Examples will be shown below to further clarify the features of the present invention.

Example 1 1) Production of prefabricated material for coating (a) Synthesis of copolymer 142 g of methyl methacrylate, 36 g of 2-hydroxyethyl methacrylate, 0.15 g of polymerization regulator (dodecyl mercaptan) and organic solvent (methyl ethyl ketone (MEK)) Put 118 g into a four-eye flask, attach a cooler, stirrer, and thermometer, add a polymerization initiator (azobisisobutyronitrile) in the presence of nitrogen gas, and polymerize.
While adding an organic solvent (MEK) during the reaction, the solid content was reduced to 31
% copolymer was obtained.

(b) Production of coating composition (2) Based on the solid content value of the above copolymer,
K) to obtain a coating composition (2) with a solid content of 9.1%.

2) Production of coating composition (a) Synthesis of copolymer 142 g of methyl methacrylate, 36 g of 2-hydroxyethyl methacrylate, 0.15 g of polymerization regulator dodecyl mercaptan, 27 g of MEK, and 9 g of dioxane.
Put 1 g into a four-eye flask, attach a cooling tube, stirrer, and thermometer, add 0.15 g of azobisisobutyronitrile as a polymerization initiator in the presence of nitrogen gas, and polymerize. During the reaction, add an organic solvent (MEK). During the addition, a copolymer with a solids content of 35% was obtained.

(b) Production of Coating Composition H 85 g of a 0.02N HC,Q aqueous solution and 46 g of IPA silica sol are placed in a four-eye flask and cooled on ice to below 30°C. A mixed solution of 189 g of methyltriethoxysilane and 48.1 g of tetramethoxysilane was added dropwise to the solution for hydrolysis. After the dropwise addition was completed, stirring was continued at 50° C. for 3 hours.

After stirring, 92.7 g of the above copolymer and 19.6 g of acetic acid were added to this.
g., 1.1 g of leveling agent, 3 g of epoxy resin and 1.4 g of curing catalyst were added and stirred thoroughly to reduce the solid content to 24.g.
A 9% coating composition II was obtained.

3) Coating composition application and curing diameter 78n
A OE polycarbonate lens was used as a transparent resin substrate, immersed in coating composition I, and pulled up at a rate of 0.
, 4 cm/see, and immediately heated at 90°C for 15 to 4 cm/see.
It was dried for 5 minutes to give a film thickness of 1.0 μm. Thereafter, the substrate was allowed to cool sufficiently, and then dipped in coating composition (2) to a film thickness of 4.5 cm at a pulling rate of 0.4 cm/see.
The coating was applied to a coating weight of 0 gm, and immediately dried and cured at 110° C. for 2 hours.

4) Evaluation method The obtained hard coat treated substrate (sample No. 1) was subjected to the following tests to evaluate the physical properties of the hard coat.

A test was conducted using steel wool with a0 surface hardness. This exam is #
The evaluation was made as follows, based on the number of scratches when a 1 kg load was reciprocated 10 times using No. 000 steel wool.

Good...Number of scratches 0-2 Normal...Number of scratches 3-5 Unsatisfactory...Number of scratches 6 or more, cross-cut at 1mm intervals with an adhesive cutter knife (IOXI
A cellophane tape (Cellotape J No. 405 manufactured by Chiban Co., Ltd.) with a tape width of 18 mm was used to peel off the hard coat coated with O (total of 100) five times. It was evaluated as follows.

Good...Film remaining 100/100 Normal...Film remaining 90-99/100 Unsatisfactory...Film remaining 89 or less/100 C9 hot water resistance Check for abnormalities when immersed in 85℃ hot water for 30 minutes. Examined.

d. Appearance The presence or absence of air bubbles, cloudiness, whitening, unevenness, etc. was examined.

Examples 2 to 12 The composition of the copolymer of coating composition (1) was as shown in Table 1, the composition of the copolymer of coating composition (H) was as shown in Table 2, and the composition of coating composition II was as shown in Table 1. The present invention was prepared by making the composition as shown in Table 3, and combining the resulting coating composition (1) and coating composition (II) as shown in Table 4, and operating in the same manner as in Example 1. Hard coat treated substrates (Samples Nos. 2 to 12) were obtained.

Furthermore, the obtained hard coat was subjected to a physical property evaluation test in the same manner as in Example 1. The results are also shown in Table 4.

Comparative Example 1 Coating composition with hard coating
Treatment was performed only with BJ. Other than that, the same operation as in Example 1 was performed.

Regarding the obtained hard coat (Sample No. 13), a physical property evaluation test was conducted in the same manner as in Example 1.

The results are shown in Table 5.

Comparative Example 2 The same operation as in Example 1 was performed except that the hard coating was treated with a two-component hard coating agent.

The obtained hard coat (sample No. 14) was subjected to a physical property evaluation test in the same manner as in Example 1.

The results are shown in Table 5.

Comparative Example 3 The same operation as in Example 1 was performed except that the hard coating was treated with a one-component hard coating agent.

The obtained hard coat (sample No. 15) was subjected to a physical property evaluation test in the same manner as in Example 1.

The results are shown in Table 5.

Claims (3)

[Claims] (1) 60 to 90 parts by weight of at least one ester selected from methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxymethyl methacrylate. , hydroxyethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid, a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid. 10 to 40 parts by weight of at least one species, total 100
Solid content consisting of 5 parts by weight of copolymer and organic solvent
15% of coating composition I was coated on a transparent resin substrate as an undercoat, and on top of that, (a) R^1Si(OR^2)_3 and Si(OR^3)
_4 (However, R^1 is a methyl group, ethyl group or propyl group, R^2 is a methyl group, ethyl group or propyl group,
(b) SiO_2 Organosilica sol 10 whose powder is dispersed in an organic solvent and whose content is 20 to 40% by weight
~20 parts by weight, (c) 60 to 90 parts by weight of at least one selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl. From acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, compounds having an amide group of acrylic acid, compounds having a nitrile group of acrylic acid, compounds having an amide group of methacrylic acid, and compounds having a nitrile group of methacrylic acid. A total of 10 to 40 parts by weight of at least one selected from the group consisting of 1
(d) 0.5 to 8 parts by weight of a copolymer consisting of 0.00 parts by weight, (d) an epoxy resin having two or more epoxy groups;
Solid content consisting of 1.5 parts by weight and (e) 0.3 to 1 part by weight of curing catalyst, a total of 100 parts by weight, and an organic solvent.
A method for producing a hard coat with excellent scratch resistance, characterized by coating with 0% coating composition II as an overcoat. (2) 60 to 90 parts by weight of at least one ester selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxymethyl methacrylate. , hydroxyethyl methacrylate, hydroxypropyl methacrylate, a compound having an amide group of acrylic acid, a compound having a nitrile group of acrylic acid, a compound having an amide group of methacrylic acid, and a compound having a nitrile group of methacrylic acid. 10 to 40 parts by weight of at least one species, total 100
The undercoat in the method for producing a hard coat with excellent scratch resistance according to claim 1, characterized in that the undercoat is made of a copolymer consisting of parts by weight and an organic solvent, and has a solid content of 5 to 15%. Coating composition used. (3) (a) R^1Si(OR^2)_3 and Si(OR
^3)_4 (However, R^1 is a methyl group, ethyl group or propyl group, R^2 is a methyl group, ethyl group or propyl group, R^
(b) SiO_2 powder is Organosilica sol 10 dispersed in an organic solvent and having a content of 20 to 40% by weight
~20 parts by weight, (c) 60 to 90 parts by weight of at least one selected from esters consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, and hydroxymethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl. From acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, compounds having an amide group of acrylic acid, compounds having a nitrile group of acrylic acid, compounds having an amide group of methacrylic acid, and compounds having a nitrile group of methacrylic acid. A total of 10 to 40 parts by weight of at least one selected from the group consisting of 1
(d) 0.5 to 8 parts by weight of a copolymer consisting of 0.00 parts by weight, (d) an epoxy resin having two or more epoxy groups;
1.5 parts by weight and (e) curing catalyst 0.3 to 1 part by weight, totaling 100 parts by weight, and an organic solvent, and the solid content thereof is 20 to 30%. A coating composition for use in an overcoat in the method for producing a hard coat with excellent scratch resistance as described in 1.