JPH02163134A - Polycarbonate resin molded article having improved wear resistance and weatherability and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject molded article useful for the tail lamp of automobile, etc., having excellent wear resistance and weatherability by mixing relatively large amount of an ultraviolet light absorber into a specific monomer mixture. CONSTITUTION:(i) 30-100wt.% multifunctional monomer having at least three (meth)acryloyloxy groups in a molecule, containing >=20wt.% acrylate expressed by formula I (n is 1-4; at least three of X are expressed by formula II, etc., and the rest is OH group) is mixed with (ii) 0-50wt.% urethane acrylate expressed by formula III (R1 is said oxy; R2 is H or methyl; l, m and n are 1-8; y is 0-10) and (iii) 0-50wt.% monomer having OH group or cyclic ether bond, etc., on side chain to obtain a monomer mixture (A). Next, 20-95 pts. the mixture (A) is mixed with (B) 80-5 pts. solid component of colloidal silica containing silica particles having 1-200mmu primary particle diameter and 100 pts. in total of (A) and (B) is coated with covering material containing 0.5-20 pts. ultraviolet light absorber, then active energy rays are irradiated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a polycarbonate resin molded article having improved abrasion resistance and weather resistance, the surface of which is coated with a crosslinked cured film, and a method for producing the same. be.

[Conventional technology]

In general, polycarbonate resins have excellent properties such as transparency, easy moldability, heat resistance, and impact resistance, and are being developed for a wide range of applications. However, due to the lack of surface hardness, the surface is easily damaged, resulting in lower product yield and poor appearance, so there is a strong demand for improved wear resistance.

In addition, polycarbonate resin lacks weather resistance compared to other synthetic resins, and when used outdoors, it suffers from significant appearance deterioration such as decreased transparency, cracks, crazing, and increased yellowish color, making it unsuitable for practical use. Currently, there is no such thing, and there is a strong demand for improvement in weather resistance.

In particular, there is a strong demand for improvements in both abrasion resistance and weather resistance for applications such as cover lenses for automobile headlights, tail lamp covers, and glazing materials for automobiles.

Various proposals have been made to improve the abrasion resistance and weather resistance of polycarbonate resin molded products, but most of them are
It is related to the coat system.

A specific example of a two-coat system is to apply a paint containing an ultraviolet absorber to an acrylic, melamine, urethane, or silicone resin, oligomer or monomer to the surface of a polycarbonate resin molded product. death,
Next, a film is formed by irradiating heat, ultraviolet rays, or active energy rays such as electron beams, and then a coating made of acrylic, melamine, urethane, silicone, etc. There is a method of forming a crosslinked cured film by irradiating active energy rays such as rays.

The feature of this proposal is the undercoat layer (primer layer)
This is intended to improve weather resistance by absorbing ultraviolet rays and other rays that cause deterioration of the resin surface, preventing peeling of the coating and charging.

However, the problem with two-coat systems is not only the adhesion of the undercoat layer film to the surface of the polycarbonate resin molded product, but also the importance of providing sufficient adhesion at the interface between the undercoat layer and topcoat layer (cured film). However, the adhesion between the layers varies greatly depending on the degree of curing of the undercoat layer. In other words, in order to satisfy the performance of both interfacial adhesion and abrasion resistance, it is necessary to set the degree of curing of the undercoat film within a certain range, but this depends on the components forming the film and the processing. In many cases, it is not easy to obtain a product with excellent performance for boat fishing. Furthermore, in the case of the 2-co-F system, not only the processing steps are complicated, but the processing time is also long, and there are many economical disadvantages.

The present inventors were fully aware of the problems with such a two-coat system, and investigated a cured film that provides wear resistance, scratch resistance, and weather resistance with a one-coat system. It has been demonstrated that a coating material composition in which a monomer mixture containing a functional monomer contains an ultraviolet absorber and a specific thermoplastic resin has excellent effects on improving abrasion resistance, scratch resistance, and weather resistance. JP-A-56-127655 to present heading suggestions
Publication No.).

This composition is applied to the surface of a polycarbonate resin molded product and then irradiated with ultraviolet rays in an air atmosphere to form a cured film on the surface.The resulting molded product has been tested in weather resistance tests such as accelerated exposure and outdoor exposure. It also had good yellowing resistance, transparency, gloss retention, etc., and was excellent in weather resistance.

[Problem to be solved by the invention]

However, it is necessary to add a relatively large amount of ultraviolet absorber to the above-mentioned coating material composition to prevent deterioration of the surface of the polycarbonate resin molded product, and in this case, the crosslinking density of the cured film is lower than that without the addition of ultraviolet absorber. Because the wear resistance and scratch resistance are more likely to deteriorate than those of other types, even higher levels of abrasion resistance and scratch resistance are desired.

[Means to solve the problem]

Therefore, the present inventors conducted intensive studies to improve the abrasion resistance and scratch resistance of the cured film in the presence of a relatively large amount of ultraviolet absorber. We have discovered that the above-mentioned problems can be solved by forming a coating composition consisting of a monomer mixture, a specific yy component, and an ultraviolet absorber on the surface of a polycarbonate resin molded product as a crosslinked cured coating, and the present invention has been made. I have reached the point where I have completed the .

The gist of the present invention is the following general formula (1)% formula% (wherein n is a positive integer of 1 to 4, and at least 3 or more X are OH, -CH-000 - group or on, -
o(am,)coo- group, and the rest are 10H groups. ) 30 to 100% by weight of a polyfunctional monomer (a) having 3 or more (meth)acryloyloxy groups in one molecule, containing 20% by weight or more of polypentaerythritol poly(meth)acrylate represented by The following general formula (II) R2 ■ R1-0HI OTi 0-CO1'IN (OHI
)z-NHOOOf(OHI)]1l1)-000-
(C"rin 000V (CHZ) m 0001)N -
(Orit) 穐-NII100OOH-OH, -R.

(II) (In the formula, R1 is an acryloyloxy group or a methacryloyloxy group, R1 is hydrogen or a methyl group, 1.m and n are positive integers of 1 to 8, and y is 0 to
It is a positive integer of 10. ) Urethane acrylate (b) 0 to 50% by weight having two (meth)acryloyl IW oxyV groups in one molecule, and a hydroxyl group and/or a cyclic ether bond and/or a chain ether bond in the side chain Monomer mixture a) consisting of 0 to 50% by weight of a monomer (c) having one (meth)acryloyl μoxy group in one molecule having
~95 parts by weight, and a solid content of colloidal silica (B) containing silica particles with a missing particle size of 1 to 200 millimicrons: 80~
A cross-linked cured film containing 15 to 20 parts by weight of ultraviolet absorber (0) per 100 parts by weight of the total amount including 5 parts by weight is formed on the surface of the molded product to improve wear resistance and weather resistance. A polycarbonate resin molded article and a method for producing the same.

In the present invention, the polyfunctional monomer (a) having five or more (meth)acryloyloxy groups in one molecule has the effect of improving the abrasion resistance, scratch resistance, and surface hardness of the cured film, and Even in the presence of a large amount of ultraviolet absorber, it has the effect of improving the hardening of the film during ultraviolet irradiation, and even when the exposure atmosphere is air, nitrogen, argon,
Shows the same hardenability as in inert gas such as hypochlorite dioxide,
The obtained cured film has good appearance such as transparency, and has good adhesion to the molded article substrate.

The polyfunctional monomer used in the present invention has the following general formula (
I) (wherein, n is a positive integer of 1 to 4, and at least three of X are OH, -0'H-Coo- groups, or 0 = O
(013) is a Coo- group, and the rest are -OR groups.

) Polypentaerythritol poly(meth)acrylic V-), such as diventaerythritol μtri(meth)
Acrylate, dipentaerythritol tetra(meth)
Acrylate, dipentaerythritol penta(meth)
Acrylate, dipentaerythritol hexa(meth)
Acrylic V-) and the like are particularly preferred.

Polypentaerythritol polyacrylate of general formula (1) can be used alone as the polyfunctional monomer (a) component without any particular problem, but when the cured film is made relatively thick, In order to prevent the occurrence of taps,
It is preferable to use a polyfunctional monomer having three or more (meth)acryloyloxy V groups in one molecule. As these monomers, the compounds described in JP-A No. 63-92675 can be used, but in the present invention, the following general formula is used: !=cu-co.

Group or 01)! , =O(OI(3)Coo- group, and the rest are -Fi, hydroxyl group, amino group, and alkylene group are substituted alkylene groups, J*n@.

ns* “4 e”1 * m1# ms and m4
is 0%1′! or 2, and X is a positive integer from 1 to 10. ), such as malonic acid/trimethylolethane/acrylic acid, malonic acid/trimethylolpropane/acrylic acid, succinic acid/trimethylolethane/acrylic acid, succinic acid/trimethylolpropane/acrylic acid, adipic acid/ Ester compounds synthesized from combinations of compounds such as trimethylo-ethane/acrylic acid or adipic acid/trimethylo-μpropane/acrylic acid; (acryloyl μoxine ester lv) isocyanurate, tris(methacryloyloxyethyl)isocyanurate, cabrolactone-modified tris(acryloyloxy group thiA/)isocyanurate, caprolactone-modified tris(methacryloyloxyethyl/1/)isocyanurate Compounds such as the following general formula (V) (where n is a positive integer of 1 to 8, or at least two CH = aU-○O- groups or OR, =O(O
B,) Coo- group, the rest am, =ca-coo-(
cH,), -oco- group or an, -c(c horse)-o
oo- (ouma), -000- group. )(V) (where n is a positive integer of 1 to 8, R is a hydrogen atom or a methyl group, and X is cH1=oi-coo-oH, - group or 01)1. −
0 (OHρ-000-C-group), for example, polyisonanate synthesized from 3 moles of hexamethylene diisocyanate and one -OH group and two polymerization activities in one molecule. A compound synthesized from a monomer having an unsaturated group shown in the formula below (where n is a positive integer of 1 to 8, R is a hydrogen atom or a methyl group, and X is 0H8 =aH-coo-c horse- group or C horse=o (anρcoo-oH, - group), for example, hexamethylene diyrananate 17μ and one 10 in one molecule. Examples include urethane (meth)acrylates, which are compounds synthesized from a monomer having an H group and two unsaturated groups exhibiting polymerization activity.These can be used singly or in combination of two or more. However, if the polybentaerythritone μ polyacrylate of general formula (1) is less than 20% by weight of component (a), the curability will decrease. As a result, wrinkles may occur in the cured film, resulting in reduced transparency or reduced adhesion to the molded article substrate.

In the present invention, in order to improve the heat resistance of the cured film,
V-thane acrylate (b) having two (meth)acryloyloxy groups in one molecule represented by the general formula (I) is used in the monomer mixture (4) in an amount up to 50% by weight. However, if the amount exceeds 50% by weight, a decrease in curability is observed, and transparency and adhesion to the molded product substrate may also decrease. The urethane acrylate represented by the general formula (n) is a difunctional fl polyester urethane acrylate synthesized by a conventional method from a saturated dibasic acid, a dihydric alcohol-μ, a divalent isocyanate, and a hydroxyl group-containing acrylic ester. The acid is selected from succinic acid, adipic acid and sepacic acid, and the divalent alcohol is 1,4-butanediol 1.
6-hexanediol, the divalent isocyanate is hexamethylene diisocyanate, and the hydroxyl group-containing acrylic ester is synthesized from 2-hydroxyethyl acrylate or 2-hydroxypropyl acrylate V-). In more detail, it can also be synthesized using compounds described in JP-A-63-851)7.

Furthermore, in the present invention, hydroxyl groups and/or A monomer (C) having one (meth)acryloyl oxy V group in one molecule having a cyclic ether bond and/or a chain ether bond is mixed into a monomer mixture (
4) It can be used within the range of up to 50 weight Is, but if it exceeds 50 weight Is, it may damage the surface of the molded product.
In some cases, transparency may be reduced.

As this monomer (C), the monomers described in JP-A-63-831)7 can be used, but in the present invention, 2-hydroxyethyl-acryV-), 2
-Hydroxypropyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, ethoxyethyl acrylate, ethyl power! Monofunctional monomers having a hydroxyl group and/or a cyclic ether bond and/or a chain ether bond in the side chain of the monomer, such as pitol acrylate, tetrahydrofurfuryloxyethyl acrylate, and cabrocuctone-modified tetrahydrofurfuryl acrylate. is preferred.

Next, the colloidal/L/V lica containing silica particles with a primary particle size of 1 to 200 millimicrons used in the present invention is
When used in combination with monomer mixture (A), the surface hardness, abrasion resistance, or scratch resistance of the cross-linked cured film is significantly improved, and the performance of the cured film is improved even when a relatively large amount of ultraviolet absorber is blended. It exhibits the effect of not reducing the

colloid of the present invention)vV! J-force (Bl) is a colloidal solution of ultrafine particles of silicic anhydride, and the dispersion medium is water, alcohol such as methanol, ethanol, iso-propanol, n-propanol, iso-butanol, n-butanol, etc. Ketones such as methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene,
Common organic solvents such as ethyl acetate and n-butyl acetate, 2-
Examples include monomers such as hydroxyethyl acrylate and 2-hydroxypropyl acrylate, but in the present invention, colloidal silica using an alcoholic solvent such as methanol, iso-propanol, or iso-butanol as a dispersion medium is preferred.

Silica other than the colloidal silica used in the present invention, for example, fine powder silica with a particle size of several millimicrons to several tens of microns manufactured by a transfer method or a wet method, has problems with dispersion stability in the coating material composition. This is undesirable because it can cause phase separation, form hard precipitates, and furthermore, the silica can form secondary agglomerations with each other, making the crosslinked cured film matte and reducing its transparency. .

The amount of colloidal silica ■) is S10! When calculated as a solid content, it is preferably in the range of 5 to 80 parts by weight, more preferably 20 to 60 parts by weight, based on 100 parts by weight of the solid content of components (A) and (B). If more than 80 parts by weight is used, although the surface hardness is improved in a favorable direction, the appearance of the crosslinked cured film, especially the smoothness or transparency, may deteriorate, and the adhesion between the substrate and the film may also be affected. This is not preferable because it becomes defective. If the amount is less than 5 parts by weight, the effect of the combined use with component (A) will be reduced and excellent surface hardness will not be exhibited in severe wear tests, which is not preferable.

These colloidal silicas are produced by well-known methods and are commercially available. It is preferable to use particles with a diameter of 1 to 200 millimeters, particularly preferably 5 to 80 millimeters. If the particle size is less than 1 millimicron, the stability of the dispersion state is poor and it is difficult to obtain a product of consistent quality, and if the particle size exceeds 200 millimicrons, the transparency of the coating will be poor, resulting in turbidity. You can only get big things.

In the present invention, the ultraviolet absorber (c) plays the role of improving the weather resistance of the cured film and preventing the occurrence of scratches. also includes light stabilizers for polymers, such as hindered amines, which can be used as long as they are uniformly dispersed in the cured film of the present invention and have good weather resistance. From the viewpoint of improved dispersibility and weather resistance, compounds derived from benzophenone, benzotriacy, phenyl salicylate or phenyl benzoate, and cyanoacrylates with a maximum absorption wavelength in the range of 240 to 380 nm are used. Certain UV absorbers are preferred.

Specific examples of the ultraviolet absorber (c) include 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2.4-)hydroxybenzophenone, and 2-hydroxybenzophenone.
-Hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 4-dobucyloxy-2-hydroxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, λ2'-
Dihydroxy-4-methoxybenzophenone, 2.2'
-! /hydroxy-4.4-dimethoxybenzophenone, phenyl salicylate V-), p-tert-phenyl salicylate), p-(1゜1.45-tetramethylbutyA/) phenyl salicylate, 3-hydroxy-V phenyl salicylate 〃Benzoate, phenylene-1,3-dibenzoate, 2-(2-hydroxy V-5-methylphenylene 1%/)
Benzotriacy μ, 2-(2-hydroxy-5-to
h-butylphenyl A/)-5-chlorobenzotriacy μ, 2-(2-hydroxy-5-di-tart-butylphenyN)benzotriacy μ, 2-(2-hydroxy-5-tart-butylphenyl) Examples thereof include phenylene (benzo) lyazole, 2-(2-hydroxy-4-octyloxyphene A/)penztriazole, and the like. These ultraviolet absorbers may be used alone or in combination of two or more (and may also be used in combination with a hindered amine light stabilizer. As a hindered amine light stabilizer, Compounds such as those described in JP-A-63-86763 can be used.

The amount of the ultraviolet absorber (c) used is in the range of 0.5 to 20 parts by weight based on 100 parts by weight of the total amount of the monomer mixture (5) and the solid content of colloidal silica (B1). If the amount of (c) used is less than α5 parts by weight, the effect of improving the weather resistance of the cured film itself, that is, preventing the occurrence of cracking of the film, will decrease, while if it exceeds 20 parts by weight, the curability of the film will decrease. The transparency and adhesion to molded products decrease.

Furthermore, in the present invention, an organic solvent may be added to the coating material composition for the purpose of further improving the smoothness and uniformity of the coating. The organic solvent is not particularly limited as long as it satisfies the above performance. Moreover, two or more types of organic solvents may be used in combination.

Specific examples of organic solvents include ethanol, iso-propanol, n-propanol, iso-butano-p, etc.
Aromatic hydrocarbons such as carbon, benzene, ) toluene, xylene, and ethylbenzene, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethers such as dioxane, ethyl acetate, n-butyl acetate, and iso-amyl acetate. , esters such as methyl propionate and ethyl propionate, ethylene glycol monomethyl ether, ethyl glycol monoethyl ether,
, polyhydric alcohol-N derivatives such as ethylene glycol monomethyl ether, N,N-dimethylformamide F, and the like. In addition, methyl acrylate, as long as it satisfies the same conditions and has the same effects as organic solvents,
Polymerizable monomers such as ethyl acrylate, methyl methacrylate, and styrene can be used as one type of organic solvent.

The proportion of organic solvent used is polyfunctional monomer (aNo.

The range is preferably 0 to 2000 parts by weight,
If more than 2,000 parts by weight is used, the thickness of the crosslinked cured film will decrease, and the surface hardness, abrasion resistance, and scratch resistance of the film will become insufficient.

The coating composition of the present invention can be applied to the surface of a polycarbonate resin molded product by brush coating, flow coating,
Methods such as spray coating, spin coating, or dip coating are employed, but dip coating is particularly preferred in terms of workability of coating composition, smoothness and uniformity of the coating, and adhesion of the coating to the substrate. preferable.

The polycarbonate resin molded products used in the present invention include sheet-like molded products, film-like molded products, rod-like molded products molded from bisphenol type polycarbonate), aliphatic polycarbonate, diethylene glycol bisallyl carbonate, etc., and various injection molded products. Specific examples include molded products.

The coating amount of the coating material composition is such that the thickness of the cured film is 1 to 1.
30 μm, preferably in the range of 2 to 20 μm. If the film thickness is less than 1 μm, sufficient surface hardness, abrasion resistance, and scratch resistance will not be obtained, and weather resistance will not be sufficient. If the film thickness exceeds 30 μm, the adhesion to the substrate may decrease or Cracks may occur more easily.

As a means for crosslinking and curing the coating material composition, usually 20 to
An electron beam extracted from a 2000 kV electron beam accelerator,
Although it is possible to irradiate with active energy rays such as β rays, β rays, and γ rays, in order to cure easily and economically, a wavelength of 1
It is preferable to use ultraviolet light having a wavelength of 00 to 500 nm.

Although an inert gas such as nitrogen, carbon dioxide, or argon gas may be used as the exposure atmosphere for ultraviolet irradiation, the component (a) of the present invention has excellent polymerization activity by ultraviolet rays in an air atmosphere, and is therefore economical. A comfortable atmosphere is preferred.

In addition, when using ultraviolet rays as active energy rays,
In consideration of practical curing, it is preferable to incorporate a small amount of a photopolymerization initiator into the coating material composition. Specific examples of photopolymerization initiators include benzophenone, benzoin methyl ether, benzoin ethyl ether, and penzoin isopropyl ester! , benzoin isobutyl ether, acetoin, butyroin, toluoin, benzophenone, p-methoxybenzophenone, jetoxyacetophenone, α,α-dimethoxyα-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxyle), 4. 4'-bis(dimethyA/aminobenzophenone), 2-hydroxy-2-methyl-1-
Phenylpropan-1-one, 1-hydroquinecyclohexyketone, 1-(4-isopropyphene A/)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1( Carbonyl compounds such as 4-(methylthio)phenyl-2-morpholino-propan-1-one;
Sulfur compounds such as ram monosulfide; azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethybronitrile; peroxide compounds such as benzoyl peroxide and diternary petite μ peroxide; Can be mentioned. These may be used alone or in combination of two or more.

The amount of the photopolymerization initiator added to the coating material composition is preferably up to 10 parts by weight based on the monomer mixture of the head component. If the amount of the photopolymerization initiator is too large, the weather resistance of the cured film may Deterioration of color and discoloration are more likely to occur.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to examples. In addition, the evaluation in Examples was based on the following method.

1. Abrasion resistance, abrasion resistance (1) Steel war/L' scratch resistance φ0 Steel Ku, A/ (Japan Steel Woo product, trade name: Bonstar) was attached to a 25 φ circular pad and subjected to a rotary abrasion test. This pad was pressed against the surface of the sample held on the machine stand and was worn 50 times at a rotation speed of 8 Orpm under a load of 5 hours. This sample was washed using a neutral detergent, and the haze value was measured using a haze meter. Steel cool abrasion resistance is expressed as (haze value after abrasion - haze value before abrasion).

(2) Taper wear test A8'l'M According to D-1044, 3 at a load of 500f
After 00 cycles of wear, the samples were washed with a mild detergent and then cleaned with a cloth impregnated with iso-propyl alcohol.

The haze value of this was measured using a haze meter. Taper abrasion resistance is expressed as (haze value after abrasion - haze value before abrasion).

λ Adhesion Make scratches on the sample surface vertically and horizontally with a razor at 1.5-inch intervals and make 100 squares. Apply cellophane tape 25 m wide (manufactured by Chiban Co., Ltd.) to the squares. Crimp it and peel it off sharply upwards.

five appearances (1) Transparency of film It is indicated by haze value (4) using a haze meter.

(2) Crack Regarding cracks in the coating, the following judgments were made.

○: No cracks are observed even under 100x magnification.

Δ: Cracks are observed under 100x magnification, but no cracks are observed visually.

×...Cracks are visually observed.

(3) Yellowing degree Evaluation was made according to J Engineering 8K 7103.

4. Accelerated exposure test Sunshine Weather Meter (Suga Test Instruments W1eL)
-EIUN-DC! ) wo-use e-c, black panel temperature 63℃, 12 minutes rain-dry cycle 1
Weather resistance was evaluated after exposure for 000 hours and 2000 hours.

i Use a heat resistance test gear open and leave the specimen in it for 1 hour.
Cracks in the coating were observed. The heat resistance temperature was determined by visually observing the occurrence of cracks.

Examples 1 to 9 Coating material compositions shown in Table 1 were prepared. A 3cm thick test specimen obtained by injection molding a polycarbonate resin (product of General Electric Company; trade name: Lexan, grade L8-2, color tone 1)1) was immersed in this for 30 seconds.
A film was formed by pulling at a pulling speed ranging from α1 to El 5 ex/sea. After this test specimen was left for 3 minutes in a room temperature atmosphere, a high-pressure mercury lamp (I-Graphics product; output 120 W/, ozone type) was used to irradiate the test specimen in air at intervals of 155 I for 10 to 10 minutes from both sides of the test specimen. It was irradiated for 20 seconds. Table 2 shows the evaluation results of the obtained polycarbonate resin molded products. The thickness of the obtained cured film was 4 to 5 microns.

Examples 10 to 15 Coating material compositions shown in Table 5 were prepared. Using this, the pulling speed of the test specimen was set in the range of 1) to 15-78θC,
The experiment was conducted in the same manner as in Example 1 except that the standing time at room temperature was 5 minutes.

The results are shown in Table 4. The thickness of the obtained cured film was 8 to 10 microns.

Example 16, Comparative Examples 1 to 3 The coating material compositions shown in Table 5 were prepared, and experiments were conducted in the same manner as in Example 1. The results are shown in Table-6. The thickness of the obtained cured film was 4 to 5 microns.

From the results in Table 6, the case (Comparative Example 1) that does not contain the ultraviolet absorber (c) of the present invention has insufficient weather resistance;
At 0 hours, the coating was observed to be scratchy, and yellowing and adhesion were significantly reduced. When colloidal silica ω) was not included (Comparative Example 2), the wear resistance was insufficient, causing taper wear and high loads. In terms of steel wool abrasion resistance, the results showed that the scratches were large and the haze value was high, and the case of monomer mixture (4) alone (Comparative Example 3) had insufficient abrasion resistance and weather resistance. I understand.

〔Effect of the invention〕

The polycarbonate resin molded product of the present invention not only has excellent abrasion resistance, scratch resistance, and surface hardness, but also has excellent transparency, gloss retention, and film adhesion in weather resistance tests such as accelerated exposure and outdoor exposure. It has good retention properties, good yellowing resistance, and excellent weather resistance, and is particularly useful as lens covers for automobile headlights, tail lamps, side lamps, etc.

In addition, the polycarbonate resin molded product of the present invention can be produced in a one-coat system, which is advantageous both economically and in terms of equipment.
Industry 1: Excellent effects.

Claims (2)

[Claims] (1) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, n is a positive integer from 1 to 4, and at least 3 x's are CH_2=CH- COO- group or CH_2=C(CH_3)COO- group, and the rest are -OH groups.) 3 or more in one molecule containing 20% by weight or more of polypentaerythritol poly(meth)acrylate 30 to 100% by weight of a polyfunctional monomer (a) having a (meth)acryloyloxy group of It is an oxy group or a methacryloyloxy group, R_2 is hydrogen or a methyl group, l, m and n are positive integers of 1 to 8, and y is a positive integer of 0 to 10.) 0 to 50% by weight of urethane acrylate (b) having two (meth)acryloyloxy groups in the molecule, and having a hydroxyl group and/or a cyclic ether bond and/or a chain ether bond in the side chain. A monomer having one (meth)acryloyloxy group in (
c) Monomer mixture (A) consisting of 0 to 50% by weight 20
Solid content of colloidal silica (B) containing ~95 parts by weight and silica particles with a primary particle size of 1 to 200 millimicrons is 80~
A cross-linked cured film containing 0.5 to 20 parts by weight of the ultraviolet absorber (C) per 100 parts by weight of the total amount of UV absorber (C) and 5 parts by weight is formed on the surface of the molded product to provide wear resistance and weather resistance. Improved polycarbonate resin molded product. (2) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, n is a positive integer from 1 to 4, and at least 3 or more COO- group or CH_2=C(CH_3)COO- group, and the rest are -OH groups. ) Polyfunctional monomer (a) having an acryloyloxy group
30 to 100% by weight, the following general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (II) (In the formula, R_1 is an acryloyloxy group or a methacryloyloxy group, and R_2 is a hydrogen or methyl group. , l, m and n are positive integers of 1 to 8, and y is a positive integer of 0 to 10.) Urethane acrylate having two (meth)acryloyloxy groups in the molecule (b) A monomer having 0 to 50% by weight and one (meth)acryloyloxy group in one molecule having a hydroxyl group and/or a cyclic ether bond and/or a chain ether bond in the side chain (
6) Monomer mixture (A) consisting of 0 to 50% by weight 20
Solid content of colloidal silica (B) containing ~95 parts by weight and silica particles with a primary particle size of 1 to 200 millimicrons is 80~
A coating material composition containing 0.5 to 20 parts by weight of the ultraviolet absorber (C) per 100 parts by weight of the total amount including 5 parts by weight is applied to the surface of the polycarbonate resin molded product, and then active energy is applied to the surface of the polycarbonate resin molded product. A method for producing a polycarbonate resin molded article with improved wear resistance and weather resistance, the method comprising forming a crosslinked cured film on the surface of the molded article by irradiating the molded article with radiation.