JPS6352667B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to transparent silica-filled organopolysiloxane coated polycarbonate articles having a silica-filled organopolysiloxane finish that is firmly adhered to a polycarbonate substrate and methods of making the same. In particular, the present invention provides a silica-filled organopolysiloxane having an undercoat layer between the polycarbonate and the silica-filled organopolysiloxane top coat consisting of a UV-curable reaction product of a polyfunctional acrylic ester monomer and a specific organosilicon compound. The present invention relates to coated polycarbonate articles. The method for making the article comprises priming a polycarbonate substrate with an adhesion-promoting, thermosetting basecoat composition comprising a polyfunctional acrylic ester monomer, a specific organosilicon compound, resorcinol monobenzoate, and a photocuring initiator. the basecoat film is cured by exposing it to ultraviolet light, the cured basecoat surface is coated with a silica-filled curable organopolysiloxane topcoat composition, and finally the silica-filled curable organopolysiloxane is applied. It consists of a curing process. It is well known that transparent glass-like plates made of polycarbonate resin are used as structural parts such as windows and windshields. Such polycarbonate resins are easy to mold into desired shapes and have excellent physical and chemical properties, such as lower density than glass and greater resistance to breakage than glass. However, polycarbonate resins have relatively low abrasion, scratch, and scuff resistance. To overcome this disadvantage of relatively low scratch and scuff resistance, polycarbonate resins have been coated with various coatings. U.S. Patent Nos. 3451838, 3986997 and
No. 4,027,073 discloses an organopolysiloxane coating composition and a technique for applying the same to a polycarbonate resin surface. Although these coatings have a number of desirable properties, such as hardness, abrasion resistance, scratch resistance, and solvent resistance, these organopolysiloxane coatings in all cases have the desired degree of uniform adhesion and durability to polycarbonate surfaces. It does not have a certain degree. There is a need for polycarbonate articles with uniformly, strongly and durably adhered scratch, scuff and solvent resistant coatings. A principal object of the present invention is to provide such an article and a relatively simple and economical method of manufacturing it. The present invention provides silica-filled organopolysiloxane coated polycarbonate articles having an adhesion-promoting primer layer and methods of making these articles. In the present invention, prior to applying the silica-filled organopolysiloxane coating to the polycarbonate surface, a UV-curable basecoat composition containing a multifunctional acrylic ester monomer, an organosilicon compound, and a UV photoinitiator is applied. Prime the surface first. This basecoat composition is cured by exposure to ultraviolet light, and then a silica-filled organopolysiloxane coating is applied thereon. In the present invention, the aromatic carbonate polymer has the following formula: It has a repeating unit of wherein each -R- is selected from the group consisting of phenylene, halogen-substituted phenylene, and alkyl-substituted phenylene, and A and B are respectively hydrogen, a hydrocarbon group containing no aliphatic unsaturation, and an adjacent

[Formula] is selected from the group consisting of groups which together with atoms form a cycloalkane group, and the total number of carbon atoms in A and B is 12 or less. Aromatic carbonate polymers suitable for the present invention can be prepared by methods well known in the art, e.g.
It can be manufactured as described in No. 3989672. Branched polycarbonates are also encompassed by the invention,
The process involves reacting a polyfunctional aromatic compound with a dihydric phenol and a carbonate precursor to form a thermoplastic randomly branched polycarbonate in which the repeating units of the formula include branching groups. Suitable polycarbonate resins can be derived from the reaction of bisphenol-A and phosgene. Such polycarbonate has the following formula: having 10 to 400 repeating units. The polycarbonate must have an intrinsic viscosity of 0.3 to 1.0, preferably 0.40 to 0.65, measured in methylene chloride at 25°C. The UV-curable undercoat composition consists of (i) a polyfunctional acrylic acid ester monomer, (ii) a specific organosilicon compound, and (iii) a UV-curing initiator. In the present invention, the polyfunctional acrylic acid ester monomer has the general formula: It is expressed as Here, n is an integer of 2 to 8, preferably 2 to 6, particularly preferably 2 to 4,
R ¹ represents an n-valent alkyl group, substituted alkyl group, ether or polyether group, substituted ether or polyether group, alkenyl group, substituted alkenyl group, aryl group, substituted aryl group, alkaryl group or aralkyl group (herein n-valent alkyl, alkenyl, and aryl groups mean hydrogen
means a substituted n-valent aliphatic saturated/unsaturated and aromatic hydrocarbon group). Preferred alkyl groups for R ¹ are those having 1 to about 20 carbon atoms. Examples of suitable alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, isopentyl, 2,2,4-trimethylpentyl,
neopentyl, heptyl, trimethylpropyl,
Examples include hexyl, octyl, and nonyl. Unsubstituted alkyls are preferred, but substituted alkyls can also be used. Alkyl includes halogens such as fluorine, chlorine, bromine and iodine, hydroxyl,
-COOR' group and -OR' group (R' in the formula represents an alkyl group having 1 to 6 carbon atoms), -CN group,
Can be substituted with substituents such as -COOH and -NO ₂ groups. Examples of substituted alkyl include n-propyl chloride, isopropyl chloride, t-butyl bromide, 1-
Bromo-2,2-dimethylpropyl, 1-chloro-2-hydroxy-3-methylbutyl, 1,2-
Dichloro-2-methylbutyl, ethylene chlorohydrin, 3-methyl-2-hydroxybutyl,
Examples include 2,4-dihydroxypentyl, acetonitrile, and t-butyl hydroxide. Preferred alkenyls are those having 2 to about 20 carbon atoms. Examples of suitable alkenyl groups include ethylene, propylene, isobutylene, 2
-Butene, 2-pentene, 3-hexene, 2-heptene, 3-heptene, 3-methyl-2-butene, 3,3-dimethyl-2-butene, 4,4-dimethyl-2-hexene, 2,4 , 4-trimethyl-2-pentene, etc. Unsubstituted alkenyls are preferred, but also substituted alkenyls such as 4-chloro-2-pentene, 4-hydroxy-2-pentene, 3-chloro-3-hydroxy-1-propane, 3-bromo-1-propane, etc. Can be used. Preferred ether groups are those having 2 to about 20 carbon atoms. Examples of ether groups include dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, ethyl propyl ether, diisobutyl ether, propyl isobutyl ether, and the like. Suitable polyether groups contain from 3 to about 20 carbon atoms and have the general formula -( ^R4O- ) _x , where ^R4 represents a lower alkylene group and x is an integer from 2 to about 5. ). Unsubstituted ethers and polyethers are preferred, but substituted ethers and polyethers can also be used. Preferred aryl groups are those having 6 to 18 carbon atoms, namely benzene, naphthalene and anthracene. Although unsubstituted aryl groups are preferred, substituted aryl groups can also be used. Substituted aryl groups are those containing 6 to 18 carbon atoms and 1 to 3 substituents. Examples of substituted aryl groups include bromobenzene, 1,3-dichlorobenzene, nitrobenzene, 1-hydroxy-4-bromobenzene, and the like. Preferred alkaryl and aralkyl groups are 7-
It has about 20 carbon atoms. Examples of alkaryl and aralkyl groups include toluene, ethylbenzene, O-ethyltoluene, xylene,
Examples include 2-phenylpropyl and 1-phenylbutyl. In the present invention, n-valent alkyl, ether and polyether groups are particularly preferred. It should be noted that if substituents are present, they must not significantly interfere with or inhibit photocuring of the multifunctional acrylic ester monomer. Specifically, a difunctional acrylic ester monomer, i.e. diacrylate, is represented by the formula where n is 2, a trifunctional acrylic ester monomer,
That is, triacrylates are represented by the formula where n is 3, and tetrafunctional acrylic ester monomers, ie, tetraacrylates are represented by the formula where n is 4. Preferred examples of polyfunctional acrylic ester monomers of the formula are listed in Table 1. These polyacrylic esters and their production are well known to those skilled in the art. In one method of making di-, tri-, and tetraacrylic acid esters, acrylic acid is reacted with di-, tri-, or tetrahydroxyl compounds to form diesters, triesters, or tetraesters. For example, acrylic acid can be reacted with ethylene glycol to produce ethylene glycol diacrylate (Compound 2 in Table 1). Even if the undercoating composition according to the present invention contains only one type of polyfunctional acrylic acid ester monomer, two
It may also contain a mixture of more than one type of polyfunctional acrylic ester monomer. In certain instances, it is suitable for the basecoat composition to contain a mixture of two multifunctional acrylates. In the present invention, the organosilicon compound is represented by the following formula: R ² _C SiX _{4 --C} . Here, each X independently represents an alkoxy, acyloxy or aryloxy group, R ² represents an organic group having olefinic unsaturation, and c is an integer of 1/3. Preferred alkoxy groups are those having 1 to about 10 carbon atoms.
Examples of suitable alkoxy groups include methoxy, propoxy, butoxy, pentoxy, heptoxy, and the like. Preferred acyloxy groups are those having 2 to about 10 carbon atoms. Examples of suitable acyloxy groups include acetoxy, propionoxy, butyroxy, pentanoxy, hexanoxy, and the like. A preferred aryloxy group is phenoxy. ^R2 is a thermal compound that can react with a multifunctional acrylate monomer of the formula in the presence of a UV photoinitiator when exposed to UV light to improve the adhesion of the organopolysiloxane to the polycarbonate substrate. Indicates an organic group containing olefinic unsaturation that forms a cured reaction product.
R ² is the general formula: ^{acryloxyalkyl} and methacryloxyalkyl, as well as the following formula: (R ³ in the formula represents the same alkylene group as above)
selected from the group consisting of alkylmaleamidic acids represented by The undercoat composition according to the invention may contain only one organosilicon compound of the formula or a mixture of two or more, preferably two different organosilicon compounds. Thus, for example, the basecoat composition may contain two different formula compounds, two different formula compounds,
or may contain compounds of one formula and compounds of one formula. Generally, the basecoat compositions of the present invention contain, excluding solvent, about 10-90% by weight polyfunctional acrylic ester monomer or mixture thereof and about 90-10% by weight organosilicon compound, preferably about 20
~80% by weight polyfunctional acrylic ester monomer and about 80-20% by weight organosilicon compound, particularly preferably about 30-70% by weight polyfunctional acrylic ester monomer and about 70-30% by weight %
Contains organic silicon compounds. The photocurable basecoat composition also contains a photoinitiating amount, ie, an amount effective to effect photocuring of the coating composition, of a photoinitiator. Usually this amount will be about 0.01 to 10%, preferably about 0.1 to 5% by weight of the photocurable basecoat composition (excluding solvent). This additive and its curing methods are well known in the art. Examples of UV photosensitizers include ketones such as benzophenone, acetophenone, benzyl, benzyl methyl ketone; benzoin and substituted benzoins such as benzoin methyl ether, α-hydroxymethylbenzoin isopropyl ether; halogen-containing compounds such as α-bromoacetate. Phenone, p-bromoacetophenone, α-chloromethylnaphthalene; sulfur compounds such as aromatic disulfides;
and other photosensitizers, such as azides, thioketones, or mixtures or synergistic mixtures thereof;
diaryl peroxides; hydroperoxides; peracids and peresters; azo compounds; or other known free radical initiators such as di-t-butyl peroxide, benzoyl peroxide, 2,
Examples include 4-dichlorobenzoyl peroxide, t-butyl hydroperoxide, peroxyacetic acid, peroxybenzoic acid, t-butyl peroxypivalate, t-butyl peracetate, and azobisisobutyronitrile. The undercoat composition according to the invention further contains resorcinol monobenzoate. The resorcinol monobenzoate is preferably unsubstituted, although lower alkyl substituted resorcinol monobenzoates can also be used. Usually resorcinol monobenzoate is present in an amount of about 1-10% by weight.
Resorcinol monobenzoates or substituted resorcinol monobenzoates are generally not considered to directly participate in the reaction of polyfunctional acrylic ester monomers with silicon-containing compounds, and therefore are not expected to directly participate in the reaction of polyfunctional acrylic ester monomers with silicon-containing compounds. Although not expected to be directly incorporated into the cured crosslinked polymer structure formed by the resorcinol monobenzoates, these resorcinol monobenzoates nevertheless improve the durability of adhesion to the base coat layer of silica-filled organopolysiloxane finishes. It acts to promote and increase the amount of light, especially when the coated polycarbonate article is exposed to light. More specifically, when curing the undercoat layer by the action of ultraviolet light,
The resorcinol monobenzoate present in this layer is converted to dihydroxybenzophenone by UV radiation. The dihydroxybenzophenone acts as a UV absorber in the cured basecoat layer, improving the adhesion and durability of the silica-filled organopolysiloxane finish to the basecoat layer. The basecoat compositions according to the invention can also contain various matting agents, surfactants and thixotropic agents, if desired. All these additives and their uses are well known in the art and require no detailed explanation. Therefore, although only a few will be mentioned, any compound that has the ability to function as a matting agent, surfactant, etc., may have a detrimental effect on the photocuring of the basecoat composition or may reduce the transparency of the coated polycarbonate article. As long as it doesn't have a negative impact on sex,
Any one can be used. A variety of surfactants, including anionic, cationic, and nonionic surfactants, are available from Kirk-Othmer
Encyclopedia of Chemical Technology,
Vol.19, Interscience Publishers, New York,
1969, p.507-593 and Encyclopedia of
Polymer Science and Technology, Vol.13,
Intersciense Publishers, New York, 1969,
Described on p.477-486. In practicing the present invention, the polyfunctional acrylic ester monomer, organosilicon compound, ultraviolet photoinitiator, resorcinol monobenzoate, and optionally any of the other additives described above are first combined. Then, a photocurable undercoat composition is blended. Additionally, organic solvents can be incorporated into the formulation if it is desired to reduce the viscosity of the basecoat composition or to promote dissolution of the organosilicon compound. The amount of solvent normally present in the composition must be selected such that the solvent evaporates before any adverse effects due to the aggressiveness (in the sense of chemical etching) of the basecoat composition develop on the substrate. . The various components are thoroughly mixed to form a substantially uniform basecoat composition. The basecoat solution is then applied in a thin, uniform film onto the polycarbonate surface by any known means such as dipping, spraying, roll coating, etc. Typically, the basecoat composition is approximately 0.05 to 0.5 mil thick;
Preferably enough is applied to form a cured film of about 0.1 to 0.3 mil. Next, the primer film is coated with a wavelength of 1849 in an inert atmosphere, such as a nitrogen atmosphere.
Cured by ~4000 Å UV irradiation. The lamp apparatus used to generate such ultraviolet light consists of an ultraviolet light bulb consisting of a discharge lamp, which has a range from as low as a few milliTorr to about 10 mTorr.
Xenon, metal halide, metal arc, low pressure or high pressure mercury vapor discharge lamps with operating pressures up to high values such as atmospheric pressure can be used. After UV curing, a transparent subbing layer is obtained on the surface of the polycarbonate and adhered thereto. This ultraviolet curable undercoat layer is a reaction product of the above-mentioned polyfunctional acrylic ester monomer and an organosilicon compound. Without wishing to be bound by any particular theory, it is believed that curing of this basecoat composition occurs through the following reaction. (i) Mutual polymerization of polyfunctional acrylic acid ester monomers, (ii) Mutual polymerization of organosilicon compounds, and
(iii) Reaction of polyfunctional acrylic ester monomers and/or polymers with organosilicon compounds and/or polymers due to olefinic unsaturation. The resulting reaction product is a thermoset resin that is firmly adhered to the polycarbonate substrate. A silica-filled organopolysiloxane coating is applied over this UV-cured basecoat layer. In the present invention, a silica-filled organopolysiloxane coating composition containing a curable organopolysiloxane and colloidal silica is applied to a cured subbing layer and then cured to form a thermoset silica-filled organopolysiloxane coating. The silica-filled curable organopolysiloxane finish coating composition has the following formula: R ⁵ Si(OH) ₃ (wherein R ⁵ is an alkyl group having 1 to 3 carbon atoms, a vinyl group, a 3,3,3- trifluoropropyl group, α-glycidoxypropyl group and α-methacryloxypropyl group), wherein at least 70% by weight of the silanol is CH ₃ Si
Consists of a dispersion of colloidal silica in an aqueous aliphatic alcohol partial condensate of (OH) ₃ . The composition typically contains solids from 10 to 50% by weight, with the solids content being primarily about 10 to 70% by weight.
of colloidal silica and about 30-90% by weight of a partial condensate of silanol. All partial condensates of silanol, i.e. siloxanol,
Preferably produced by condensation of CH ₃ Si (OH) ₃ , partial condensates can be prepared by combining the main part obtained from the condensation of CH ₃ Si (OH) ₃ with monoethyltrisilanol, monopropyltrisilanol, monovinyltrisilanol, It can also be constituted with auxiliary moieties obtained from the condensation of silanol, mono α-methacryloxypropyltrisilanol, mono α-glycidoxypropyltrisilanol or mixtures thereof.
The composition further contains sufficient acid to have a PH in the range of 3.0 to 6.0. Maintaining the PH in this range is to prevent premature gelling of the silica-filled organopolysiloxane topcoat composition, increase shelf life, and optimize the properties of the cured coating. Suitable acids include both organic and inorganic acids, such as hydrochloric acid, chloroacetic acid, acetic acid, citric acid,
These include benzoic acid, formic acid, propionic acid, maleic acid, oxalic acid, and glycolic acid. The acid can be added to the silane (the silane hydrolyzes to form the silanol component of the composition) or to the hydrosol before mixing the two components, silane and silica hydrosol. The trisilanol component of the topcoat composition according to the invention is produced in situ by adding the corresponding trialkoxysilane to an aqueous dispersion of colloidal silica. Suitable trialkoxysilanes include methoxy, ethoxy, isopropoxy and t-
Contains a butoxy substituent. During the production of silanols in acidic aqueous media, the hydroxyl substituents condense to form -Si-O-Si- bonds. The condensation is not complete; rather, the siloxane retains a significant amount of silicon-bonded hydroxyl groups, which makes the organopolysiloxane polymer soluble in water-alcoholic solvents. This soluble partial condensate can be characterized as a siloxanol polymer having at least one silicon-bonded hydroxyl group for every three --SiO-- units. During curing of the topcoat composition on the basecoat layer, these residual hydroxyl groups condense to form sesxyloxane.
Forms R ⁵ SiO _3/2 . The silica component of the topcoat composition is present in the form of colloidal silica. Aqueous colloidal silica dispersions typically have particle sizes ranging from 5 to 150 millimicrons in diameter. These silica dispersions are made by methods well known in the art and are commercially available. In order to increase the stability of the dispersion and to form a top coat with excellent optical properties, it is preferred to use colloidal silica having a particle size in the range of 10 to 30 millimicrons in diameter. To make the silica-filled organopolysiloxane topcoat composition, trialkoxysilane is added to a colloidal silica hydrosol and then acid is added to adjust the PH to a range of 3.0 to 6.0. As previously mentioned, the acid may be added to either the silane or the silica hydrosol prior to mixing the two components. Alcohol is produced during the hydrolysis of trialkoxysilane to trisilanol. Additional alcohol, water or water-miscible solvents can be added depending on the solids percentage desired in the final coating composition. Suitable alcohols are lower aliphatic alcohols such as methanol, ethanol, isopropanol, t-butanol and mixtures thereof. Generally, the solvent system must contain about 20-75% alcohol by weight to ensure dissolution of the siloxanols formed by condensation of silanols. If desired, small amounts of additional water-miscible polar solvents, such as acetone, butyl cellosolve, etc., can be added to the water-alcohol solvent system. Typically, add enough alcohol or water-alcohol solvent to approx.
70% by weight colloidal silica and about 30-90% by weight
Solid content of approximately 10 silanol partial condensates
The composition contains ~50% by weight. The composition is aged for a short period of time to ensure the formation of partial condensates of silanols, ie, siloxanols. This condensation occurs through the hydroxyl substituent in an acidic aqueous medium.
Occurs when silanols form -O-Si bonds. The condensation is not complete, resulting in a siloxane having a significant amount of silicon-bonded hydroxyl groups. This aged silica-filled curable organopolysiloxane topcoat composition is then applied to the primed polycarbonate by any known method, such as dipping, spraying, flow coating, and the like. After the topcoat composition is applied to the primed polycarbonate, the entire polycarbonate substrate is air-dried to evaporate the volatile solvent from the topcoat composition. Heat is then applied to harden the finish coat. During curing, residual hydroxyl groups of the siloxane condense to form sesxyloxane R ⁵ SiO _3/2
occurs. The resulting silica-filled crosslinked organopolysiloxane finish adheres strongly to the polycarbonate substrate and has excellent scratch, scuff, abrasion and solvent resistance. Finish coats typically contain about 10-70% silica and about 30-90% silica by weight.
Contains organopolysiloxane present as sesxyloxane R ⁵ SiO _3/2 . The thickness of the topcoat generally depends on the application method and the weight percent solids present in the silica-filled curable organopolysiloxane topcoat composition. Generally, the higher the solids percentage and the longer the application time, the greater the thickness of the topcoat. The thickness of the cured finish is about 0.1 to 0.5 mil, preferably about 0.15 to 0.4 mil, and most preferably about 0.2 mil.
~0.25 mil is preferred. The present invention also provides a method for making scratch-, abrasion-, abrasion- and solvent-resistant polycarbonate articles. In this method, (i) a polyfunctional acrylic ester monomer represented by at least one formula, (b) an organic compound having at least one olefinically unsaturated organic group represented by the formula applying an ultraviolet curable basecoat composition containing a silicon compound, (c) an ultraviolet photoinitiator, and (d) resorcinol monobenzoate; and (ii) applying ultraviolet light of sufficient intensity for a period sufficient to cure the basecoat composition. ,
A cured undercoat containing a reaction product of a polyfunctional acrylic acid ester monomer and an organosilicon compound, and further containing a photoreaction product of resorcinol monobenzoate, an alkyl-substituted resorcinol monobenzoate, or a mixture thereof, on the polycarbonate substrate. (iii) the cured undercoat layer has the formula R ⁵ Si(OH) ₃ (wherein R ⁵ is a carbon atom number of 1 to
A partial condensation product of silanol of three alkyl groups (selected from among vinyl group, 3,3,3-trifluoropropyl group, α-glycidoxypropyl group and α-methacryloxypropyl group); so that at least 70% by weight of the silanol is CH ₃ Si
applying a silica-filled curable organopolysiloxane topcoat composition comprising a dispersion of colloidal silica in a lower aliphatic alcohol-aqueous solution of (OH) ₃ ; and (iv) removing a volatile solvent from the topcoat composition. and (v) applying heat to the topcoat composition to cure it to form a silica-filled heat-cured organopolysiloxane, ie, a sesxyloxane. In order to further clarify the understanding of the present invention, examples of the present invention are shown below. These examples are not intended to limit the invention. Example 1 By reacting 2,2-bis(4-hydroxyphenyl)propane with phosgene in the presence of an acid acceptor and a molecular weight regulator, the intrinsic viscosity was 0.57.
aromatic polycarbonate. The product is then fed to an extruder, which is operated at about 265°C. The extrudate is shredded into pellets. Next, the pellets are injection molded at about 315°C to
The test panel shall be 4 inches x 1/8 inch (thickness). Perform an abrasion test on the test panel. In this abrasion test, the abrasion resistance of a test panel with a 1/4 inch diameter hole drilled in the center is evaluated using a taper abrasion tester. The surface of the CS-10F worn wheel attached to the Taber abrasion tester is regenerated by polishing it every 200 cycles with an S-11 resurfacing disk for 25 cycles.
The weights used in combination with the CS-10F wear ring are 500g weights (multiple). Initial haze (%) is measured using a Gardner haze meter at four points around the trailing wear trajectory of the sample. Abrade the sample for 500 cycles, wash with isopropanol, and remeasure haze (%) at the same four points as above. The difference in the degree of haze (%) at the four points is calculated, and these are averaged to obtain the difference in degree of haze (%). The results are shown in Table 1. Example 2 A basecoat composition is made. For this reason, 1,6 of 50g
-Hexanediol diacrylate, 50g N-
50% ethanolic solution of [3-(triethoxysilyl)propyl]maleamidic acid (aged, i.e. long standing), 1.5 g α,α-diethoxyacetophenone, 7.5 g resorcinol monobenzoate and 750 g of isobutanol. Add 250 g of isobutanol to 250 g of this solution. This basecoat composition is applied in a thin film to the polycarbonate test panel prepared in Example 1. The polycarbonate panel is passed through a hybrid Linde light curing device to cure the film. Light curing equipment is mainly used for 2537Å, 3150Å
A variable speed conveyor runs through a room containing germicidal mercury vapor discharge lamps emitting at 3605 Å and 3605 Å, the nitrogen pressure is 25 psi nitrogen, and the conveyor speed is 30 feet per minute. After this treatment, the film is tack-free and cured. Example 3 A basecoat composition is made. For this reason, 1 of 250g,
6-hexanediol diacrylate, 125 g of a 50% ethanolic solution of N-[3-(triethoxysilyl)propyl]maleamic acid (aged), 7.5 g of α,α-diethoxyacetophenone, 1.2 g of Blend resorcinol monobenzoate and 600 g isobutanol. Dilute 250 g of this solution with 1900 g of isobutanol.
This basecoat composition is applied in a thin film to the polycarbonate test panel prepared in Example 1.
The primed panel is passed through the Linde light curing apparatus described in Example 2 to cure the film. Example 4 A basecoat composition is made. For this reason, 1 of 250g,
6-hexanediol diacrylate, 125 g α-methacryloxypropyltrimethoxysilane, 62 g trimethylolpropane triacrylate, 7.5 g α,α-diethoxyacetophenone, 36.5 g resorcinol monobenzoate and 600 g isobutanol. Blend. Add 1900 g of isobutanol to 250 g of this solution. Example 5 Commercially available aqueous colloidal silica dispersion (particle size approx.
2.5% by weight (containing 14 mm _SiO2 )
of methyltrimethoxysilane acidified by the addition of glacial acetic acid to prepare a silica-filled organopolysiloxane topcoat composition containing 37% by weight solids consisting of 50% _SiO2 . This composition was mixed for 4 hours and then further glacial acetic acid was added.
Adjust to PH3.9. This acidified composition is diluted to 18% solids by the addition of isopropanol and aged for 4 days to ensure the formation of a partial condensate of CH ₃ Si(OH) ₃ . Example 6 A polycarbonate panel prepared according to Example 1 is flow coated without a primer with the silica-filled organopolysiloxane topcoat composition prepared in Example 5. 30 panels coated without these primers
Air dry for 1 minute to evaporate the solvent, then
Bake for a period of time to cure the curable organopolysiloxane. These unprimed and primed painted panels described below were subjected to various tests to determine the durability of the coating on the substrate. One of the durability tests is a weather test, in which the paint sample is exposed to a 6KW xenon arc weatherometer (Weather-O-Meter, a trademark of Atlas Electric's weather test machine). Adhesion tests are performed on painted samples after exposure for a specified time in a Weatherometer. For the adhesion test, parallel grooves approximately 1 mm apart were cut through the coating into the substrate using a multi-blade tool, the sample was rotated 90° and the cutting operation was performed again, thus cutting 1 mm into the coating. Create a square grid pattern, apply adhesive tape to the grid area, and quickly peel off the tape. The sample fails the adhesion test if even one square in the plaid area peels off. The results of the weathering test and adhesion test are shown in Table 1. As another test to measure the durability of silica-filled organopolysiloxane coatings on substrates,
Perform a wetness test on the paint sample. In this test, the sample is subjected to a number of wet oven cycles, and after each cycle the sample is subjected to the adhesion test described above. 1
For 1 humid oven cycle, the sample was heated to a relative humidity of 99
% and placed in a chamber maintained at a temperature of 80-85〓, the temperature was raised to 140〓, the temperature was maintained at 140〓 for 6 hours,
After that, lower the temperature to 80~85〓. At this point 1
At the end of the cycle, remove the sample and perform an adhesion test. The test results are shown in Table 1. Another test to ascertain the adhesion and durability of silica-filled organopolysiloxane coatings on substrates is the sun lamp aging test. In this exam,
The sample is exposed to large amounts of ultraviolet light. In the solar lamp aging test, the paint sample is exposed to RS-sun lamp.
After irradiation for a predetermined period, the sample is taken out and an adhesion test is performed. The test results are shown in Table 1. Example 7 A primed polycarbonate panel is prepared according to Example 2 and then flow coated with a silica-filled organopolysiloxane topcoat composition prepared according to Example 5. The panels were air dried for 30 minutes to evaporate the solvent and then baked at 250°C for 1 hour to cure the curable organopolysiloxane. These base coated and top coated panels are subjected to the weathering test, wetness test, abrasion test and solar lamp aging test described above. The results are shown in Tables 1, 2, 3 and 4. Example 8 A primed polycarbonate panel is prepared according to Example 3 and then flow coated with a silica-filled organopolysiloxane topcoat composition prepared according to Example 5. The panels were air dried for 30 minutes to evaporate the solvent and then baked at 250°C for 1 hour to cure the curable organopolysiloxane. These primed and finished coated panels are subjected to the weathering test, wetness test, abrasion test and solar lamp aging test described above. The results are shown in Tables 1, 2, 3 and 4.

【table】

[Table] Table Abrasion resistance examples Difference in haze (%) 1 34 7 4.1 8 2.3

[Table] In addition, the samples prepared according to Example 7 are subjected to an abrasion test after being exposed to a weatherometer for about 1000 hours. The haze difference (%) of the sample exposed to this weathering condition is 4.2, which is almost the same as the haze difference (%) 4.1 of the sample not exposed to the weathering condition as shown in the table. As is clear from the Examples and Tables above, the durability of a silica-filled organopolysiloxane finish applied to a primed polycarbonate substrate in accordance with the present invention is superior to that of the same finish applied to an unprimed polycarbonate substrate. This is a huge improvement compared to painting. The above description is not intended to limit the present invention, and various changes can be made without departing from the gist of the present invention.

Claims (1)

[Scope of Claims] 1. A polycarbonate substrate comprising (i) (a) at least one polyfunctional acrylic ester monomer and (b) the following formula: R ² _C SiX _4-C [wherein X is alkoxy] , represents an acyloxy or aryloxy group, c is an integer of 1 to 3, and R ² is an acryloxyalkyl group represented by the following formula: CH ₂ =CH-COO-R ³ -, the following formula: A methacryloxyalkyl group represented by or the following formula: an ultraviolet curable undercoat layer containing a photoreaction product of at least one organosilicon compound represented by an alkyl-substituted maleamic acid group (in which R ³ is a lower alkylene group); (ii) a polycarbonate article coated with a cured topcoat containing a colloidal silica-filled thermoset organopolysiloxane coated on the basecoat layer. 2. The polycarbonate article of claim 1, wherein the cured basecoat layer further contains a photochemical reaction product of a resorcinol monobenzoate, an alkyl-substituted resorcinol monobenzoate, or a mixture thereof. 3 The polyfunctional acrylic acid ester monomer has the following formula: [H ₂ C=CH—COO—] _o R (n in the formula is an integer of 2 to 4, and R is n-valent alkyl, substituted alkyl, ether , substituted ether, polyether, substituted polyether, alkenyl, substituted alkenyl, aryl, substituted aryl,
3. The article according to claim 2, which is an alkaryl or aralkyl group. 4. The article according to claim 3, wherein R represents an n-valent alkyl, ether, polyether, alkenyl, aryl, alkaryl, or aralkyl group. 5. The article according to claim 4, wherein R represents an n-valent alkyl, ether or polyether group. 6. The polyether group according to claim 5, wherein the polyether group is represented by the formula -( _R ¹ O- ⁾ Goods. 7. The article according to claim 1, wherein the R ³ group is a propylene group. 8. The article according to claim 7, wherein X is an alkoxy group and c is 1. 9. The article according to claim 8, wherein the alkoxy group is an ethoxy group. 10. The article according to claim 8, wherein the alkoxy group is a methoxy group. 11 The thermosetting organopolysiloxane has the following formula: R ⁴ Si(OH) ₃ (R ⁴ in the formula is an alkyl group having 1 to 3 carbon atoms, a vinyl group, a 3,3,3-trifluoropropyl group, A condensation product of a silanol having α-glycidoxypropyl group or α-methacryloxypropyl group, in which at least 70% by weight of the silanol is CH ₃ Si(OH) ₃ Articles described in paragraph 2. 12 The thermosetting organopolysiloxane is
12. The article of claim 11, which is a condensation product of _CH3Si (OH) ₃ . 13. The article of claim 11, wherein said top coat contains about 10-70% by weight colloidal silica and about 30-90% by weight silanol condensation product.