JPS6053702B2 - coated polyester molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyester moldings coated with specific polymers.

More specifically, the present invention relates to a polyester molded article whose surface performance is significantly improved by coating it with a polymer mainly composed of a specific melamine group-containing (meth)acrylate. Polyesters synthesized from aromatic dicarboxylic acids and aliphatic diols, typified by polyethylene terephthalate, have excellent physical properties such as mechanical and electrical properties, and are used as molded products such as fibers, films, sheets, and plastics. It is an important polymer compound with a wide range of uses.

However, since such a polyester molded product also has a flexible surface, its abrasion resistance is low, and the surface is easily damaged by dirt, dust, scratches, etc.

The fine scratch marks thus generated on the surface cause the surface to become cloudy, resulting in loss of transparency and surface smoothness of the molded product itself. This phenomenon often significantly reduces or eliminates the practical value of molded products such as films, sheets, and plastics.
Various methods have been proposed to date to improve the abrasion resistance of polyester molded products.

As such methods, vapor deposition of inorganic glass, SiO2, etc., and surface coating with condensates of organosiloxane, polysilicic acid, etc. are mainly known. However, polyester generally has high crystallinity and poor adhesion, so there are still very few polyesters that have high abrasion resistance, adhesion, flexibility, dimensional stability, workability, etc. I can't see it. As a result of intensive research in order to solve the drawbacks of such polyester molded products without impairing the inherent desirable properties of polyester, the present inventor discovered that a specific (meth)acrylate containing a melamine group in the molecule By coating the surface of the polyester molded product with the main polymer, the abrasion resistance is significantly improved, and the coated molded product satisfies the above requirements and has excellent durability, especially moisture resistance and water resistance. The present invention was achieved by discovering that the present invention is superior. That is, the present invention provides the following general formula (1) [wherein Rll, Rl2, Rl3 are each independently a hydrogen atom or a methyl group; R2l, R22. R23 is each independently an alkylene group having 2 to 10 carbon atoms,
R3l, R,2, R33 are hydrogen atoms, carbon atoms 1 to 1
0, in the formula RlO is a hydrogen atom or a methyl group, and R
2.

is an alkylene group having 2 to 10 hydrogen atoms. ) is a group selected from the group consisting of groups represented by ] This is a polyester molded product coated with a vinyl polymer mainly composed of melamine group-containing (meth)acrylate.

The features of the coated polyester molded product of the present invention, including its manufacturing process, will be explained in more detail as follows.

(1) High hardness is exhibited because a high-order network structure is formed based on a polyfunctional acrylate polymer.

However, despite this high network structure, polymerization shrinkage is small because the monomer has a so-called star-shaped structure and a bulky heterocycle is located at the center. Therefore, it has high dimensional stability and can suppress the curling phenomenon that often occurs when sewing thin or sheet-like coverings. (2) Since it is an organic coating, it is highly flexible and can withstand excessive deformation such as bending and elongation associated with thin materials, and does not cause cracks.

(3) Since it is a (meth)acrylate type, dipole-dipole interaction with the ester bond of the polyester material,
Since the coating has an aromatic heterocycle, it exhibits high affinity with the polyester and therefore high adhesion, probably due to interaction based on dispersion force with the aromatic ring of the base polyester. (4) Since radical reactions are used, the reaction is fast and can be cured at low temperatures.

Therefore, the process can be easily made continuous, which is advantageous for long products. On the other hand, condensation-based coatings such as organosiloxane and polysilicic acid react slowly and require long-term treatment at high temperatures, making them unsuitable for long objects. Also low temperature,
Attempts have been made to add acid, base, or metal catalysts to shorten the processing time, but the use of such catalysts causes deterioration of other physical properties and durability. Also, in the case of vapor-deposited coatings, it takes time to make the coating thick enough to exhibit abrasion resistance, thus affecting cost. (5) Since it is an acrylate type, thermal polymerization using a radical initiator is possible, and photopolymerization using a sensitizer is also possible.

Moreover, it is a polyfunctional acrylate and is air-curable in most cases, which is extremely advantageous. (6) Based on the fact that the melamine group-containing (meth)acrylate does not have methylolmelamine type active methylene, it has excellent durability, especially water resistance,
Excellent moisture resistance.

RlO-Rl3, R2O-R2 of the melamine group-containing (meth)acrylate of the general formula used in the present invention
3 and R3l to R33, RlO,R
l,,Rl.

and Rl3 each independently represent a hydrogen atom or a methyl group. R2O, R22. R22 and R23 are each independently a linear or branched alkylene group having 2 to 10 hydrogen atoms, preferably 2 to 6 hydrogen atoms. Preferred alkylene groups include -+. CH2+-2~6, [-゛
1℃H2・d-CH2- is mentioned--C month-. C-th
-1.

Also, ゞH2゛0H2- and R. ,Up. - is the most suitable example considering the availability of raw materials. R3l, R3
2 and R33 are each independently a hydrogen atom, carbon atom number 1
~10 hydrocarbon groups and the following formula [wherein Rl. ,R2
O is as defined above. The hydrocarbon group is preferably an aliphatic, alicyclic, or aromatic hydrocarbon group having 1 to 8 carbon atoms. Those preferably used include aliphatic hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, neopentyl, hexyl, and benzyl; alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl; phenyl and tolyl. Examples include aromatic hydrocarbon groups such as.

Moreover, such a hydrocarbon group may have a substituent such as a halogen. The melamine group-containing (meth)acrylate of the present invention is a melamine obtained by, for example, a dehydrochlorination reaction between a primary and/or secondary amine having a hydroxyl group and cyanuric chloride, or an addition reaction between melamine and an epoxy compound. Easily synthesized by reacting a group-containing polyol with (meth)acrylic acid and/or (meth)acrylic acid derivatives such as (meth)acrylic anhydride, (meth)acrylic acid chloride, and (meth)acrylic acid ester. can do.

During the synthesis of the (meth)acrylate represented by the above general formula, various side reaction products may be obtained depending on the reaction conditions, etc., but if the amount of the by-products is small compared to the target product, the reaction may be delayed. The mixture can be used for the purpose of the present invention as is.

The polyester referred to in the present invention is not particularly limited, but even if the polyester of the present invention has low adhesiveness, for example, 85 mol% or more of its 7 repeating units is composed of an aromatic dicarboxylic acid and an aliphatic diol, it has good adhesiveness. It is particularly effective to apply the present invention to such polyesters because of their properties.

Examples of aromatic dicarboxylic acids include terephthalic acid, j-isophthalic acid, 4,4″-diphenyldicarboxylic acid, and 2.6″-diphenyldicarboxylic acid.
-naphthalene dicarboxylic acid, etc., preferably terephthalic acid and 2,6-naphthalene dicarboxylic acid.

succinic acid in a proportion of less than 15 mol% of the dicarboxylic acid component;
Dicarboxylic acids such as adipic acid, sebacic acid and hexahydroterephthalic acid, and oxycarboxylic acids such as ε-oxycaproic acid and oxybenzoic acid may be contained.

The diol component of the polyester is an aliphatic diol, such as ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanedimethanol, etc., with ethylene glycol and tetramethylene glycol being particularly preferred. As the polyester of the present invention, polyethylene terephthalate and polybutylene terephthalate are particularly preferred.

The term "polyester molded product" as used in the present invention refers to all molded products made of polyester, preferably films, sheets, or plastics.

The coated polyester molded product of the present invention can be obtained by applying a coating solution containing melamine group-containing (meth)acrylate as a main component to the surface of the polyester molded product and polymerizing it on the surface of the molded product. It will be done.

The coating liquid comprises at least one compound selected from the (meth)acrylates represented by the above general formula, a polymerization initiator, a polymerization inhibitor as a storage stabilizer, and various other additives as necessary, It can also be used after being diluted with a suitable organic solvent. Such a solvent is used for the purpose of adjusting the viscosity of the coating liquid and improving the "wetting" of the molded article.

Specifically, hydrocarbons such as benzene, toluene, xylene, ethylbenzene, n-hexane, heptane, petroleum ether, ligroin, cyclohexane, methylcyclohexane, methylene chloride, chloroform, trichloride, etc. ethylene dichloride, perchloride, 1,1,1-
Halogenated hydrocarbons such as trichloroethane, 1,1,2,2-tetrachloroethane, propylene dichloride, chlorobenzene, bromoethane, bromoform, etc., methanol, ethanol, iso-1propanol, n-butanol, Sec-butanol, amyl alcohol , alcohols such as methyl amyl alcohol, cyclohexanol, ethylene glycol, trimethylene glycol, propylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone,
Ketones such as cyclohexanone, ethers such as ethyl ether, propyl ether, butyl ethyl ether, isoamyl ether, diethylene glycol dimethyl ether, trimethylene glycol dimethyl ether, tetrahydrofuran, dioxane, anisole, phenethole, acetonitrile, propylnitrile, and pronitrile Nitriles such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, amyl acetate, methyl benzoate, ethyl benzoate and other esters, N,N-dimethylformamide, Examples include aprotic polar solvent systems such as N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and water. These solvents can be used alone or in combination of two or more. The polymerization initiator used varies depending on the curing method. In the case of ultraviolet curing, benzoin such as benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, etc. Ethers; benzyl, benzyl dimethyl ketal, benzyl diethyl ketal, and other benzyl ketals; 2-alkylanthraquinones, diacetyl, etc.; in the case of heat curing, azo compounds such as azobisisobutyronitrile; benzoyl peroxide, Examples include peroxides such as lauryl peroxide, di-tert-butyl peroxide, dicumyl peroxide, and cumene hydroperoxide. When ultraviolet rays and heat are used together, polymerization initiators can also be used in combination.Amount used is usually 0 for the (meth)acrylate.
．． It is in the range of 0.01 to 1 slag weight%. Furthermore, when using gamma rays, electron beams, or the like as a curing means, it is not necessarily necessary to add a polymerization initiator. Polymerization inhibitors as storage stabilizers are not necessarily required, but include, for example, hydroquinone, hydroquinone monomethyl ether, catechol, 2,6-di-tert-butylphenol, N-nitron diphenylamine, phenothiazine, etc. Usually, the (meth)acrylate 10 to 1000 ppm is used.

As various other additives, for example, stabilizers such as ultraviolet absorbers and antioxidants, pigments, optical brighteners, fillers such as glass fibers, glass powders, clays, magnetic materials, and carbon may be added.

Moreover, the coating liquid is represented by the general formula (meth)
Conventional vinyl monomers can be added to an extent that does not impair the abrasion resistance of the cured acrylic ester product and its excellent adhesion to polyester molded products.

Such monomers include styrene, methyl methacrylate, acrylonitrile, acrylic acid, vinyl acetate, methacrylamide, 2-hydroxylethyl acrylate, tetrahydrofurfuryl methacrylate, 2-ethylhexyl methacrylate, tetramethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene Examples include glycol dimethacrylate, trimethylolpropane triacrylate, bisallyl carbonate, diallyl phthalate, and n-butyl allyl ether. The coating solution can be applied (coated) to the polyester molded product by dipping it in the coating solution, spraying, applying with a brush, doctor knife, percoater, coal, etc., and roll transfer. The method is also preferably used.

Further, in order to further improve the adhesion to the polyester molded product, the surface of the polyester may be treated.

Examples of such surface treatments include pretreatments such as corona discharge treatment, plasma treatment, glow discharge treatment, flame treatment, ultraviolet ray or electron beam treatment, ozone oxidation treatment, and hydrolysis treatment, and a method of coating an adhesive layer. When the coating liquid is diluted with a solvent, the polyester molded article coated with the coating liquid can first be heated to remove the solvent, or if it does not contain a solvent, it can be directly polymerized.

Polymerization (curing) is carried out by ultraviolet light, heat, gamma rays, electron beams, or a combination thereof, preferably by ultraviolet light, heat, or a combination thereof. Most of the (meth)acrylates represented by the above general formula are air-curable (not inhibited by oxygen in the air), so they can be polymerized using an inert gas such as nitrogen or under reduced pressure. In many cases, it is not necessary to block the air with a film, glass, etc. The thus obtained coated polyester molded product of the present invention has excellent surface performance, particularly excellent abrasion resistance, and furthermore, the coated product has extremely excellent adhesion to the polyester molded product. In addition, the coating does not peel off even under usage conditions such as bending or bending.

Therefore, the coated polyester molded product of the present invention can be applied to a wide range of uses as an abrasion-resistant film, sheet, and plastics. EXAMPLES Hereinafter, the present invention will be explained with reference to Examples, but the present invention is not limited thereto in any way. In addition, all parts in the examples mean parts by weight.

Example 1 A solution consisting of 184.4 parts of cyanuric chloride and 41 m of dioxane was poured into 60 CH of ice water with vigorous stirring to obtain a slurry.

Diethanolamine 316. ? was added dropwise to the slurry while externally cooling the reaction system to a temperature of 3 degrees or less. After the dropwise addition, several drops of the phenolphthalein solution were added, and the reaction system was gradually heated to reflux temperature, which was further maintained under reflux for 2 hours. During the heating and refluxing period, a solution consisting of 1 part of sodium hydroxide and 3 (1) parts of water was added dropwise while paying attention to coloration of phenolphthalein in the reaction system. The reaction mixture was then cooled and the solvent was removed to dryness. The reaction mixture was extracted with n-butanol and directly recrystallized to obtain hexakis(hydroxyethyl)melamine 24CB in the form of needles. 39.1 parts of hexakis(hydroxyethyl)melamine and 0.03 m of p-methoxyphenol were dissolved in 10 parts of acrylic acid, and a part of acrylic anhydride was added dropwise to the solution at room temperature while stirring, and then 40 parts of acrylic anhydride was added dropwise to the solution at room temperature with stirring. The reaction was carried out at ~5CfC for 5 hours. The reaction was poured into 12(1) parts of water under vigorous stirring and the organic layer was separated. Add 2 (1) parts of ethyl acetate to the organic layer, wash twice with an aqueous sodium carbonate solution, repeat the washing with water three times, separate the organic layer, add (9) parts of magnesium sulfate to the organic layer, and after drying, remove the solvent. was distilled off under reduced pressure to obtain a viscous liquid of hexakis (acryloyloxyethyl) melamine.The infrared absorption spectrum of this material shows the characteristic absorption of the ester group at 1730c!n-1, 162h-1, 16ao-1 Characteristic absorption of C-C was observed in 1540, 1490, and 805a-1. Also, the magnetic resonance absorption spectrum showed δ3.8ppm (triplet) and 4.4ppm.
(Tripled) to one CH2-CH2, 5.7 to 6.7
A characteristic absorption of CH2=CH was observed at ppm.

Moreover, the elemental analysis values were as shown below, and were in good agreement with the theoretical values.

A coating solution consisting of 5 parts of the above melamine group-containing acrylate, 0.5 parts of benzyl methyl ketal, and 5 parts of methyl isobutyl ketone was prepared.

The coating liquid was coated for 75 minutes using a percoater (#5).
Coated on a μ-thick polyester terephthalate film stretched 3 times in the longitudinal direction and 3 times in the transverse direction, and dried with hot air at 120°C.
K. W. UV curing was performed using a high-pressure mercury lamp. The cured film had a thickness of 3 μm and adhered well to the substrate. The sharpness of the coated surface was 100%, and no scratches appeared even when rubbed vigorously with steel wool (#0000). Further, as a result of a sand drop test (#80 carborundum 500y), the polyethylene terephthalate surface had a haze value of 50 to 60%, whereas the coated surface had a haze value of 3% or less. Example 2 3 (1) parts of hexakis(2-hydroxypropyl)melamine was obtained in the same manner as in Example 1 except that 40 parts of diisopropanolamine was used in place of 316.2 parts of dithaleramine.

Hexakis(2-hydroxypropyl)melamine47.
5 parts and 0.0 parts of p-methoxyphenol. Add the name part to 8 parts of dissolved acrylic anhydride at room temperature while stirring,
The reaction temperature was then maintained at 40-50'C for 6 hours.

During this time, the reaction system changed from a slurry to a homogeneous solution. The resulting reaction mixture was poured into 80 g of water with vigorous stirring, and the organic layer was separated. From the obtained organic layer, 71 parts of a viscous liquid of hexakis(2-acryloyloxypropyl)melamine was obtained in the same manner as in Example 1. A coating solution consisting of the above melamine group-containing acrylate (50 W), benzyl dimethyl ketal (0.5 part) and isopropyl alcohol (50 W) was prepared.

The coating solution was applied onto an unstretched polyethylene terephthalate film (250 μm thick), dried at 50° C., and cured with ultraviolet rays to obtain a polyester molded product having a 3 μm thick coating. The molded product has good adhesion to the coating and the base, is transparent and smooth, and the coating surface is hardly scratched even when rubbed vigorously with steel wool, and the sand drop test (500y) shows no haze. The value was 3-4%.
This coated molded product was immersed in 8 generations of hot water for 8 days, but there was no change in appearance or performance. In addition, the surface side of the polyester was attacked and devitrified by organic solvents such as acetone, methylene chloride, toluene, and dioxane, but the coated surface was not attacked by these solvents at all and no change in transparency was observed.Example 3 to 6, Comparative Example 1 In the same manner as in Example 1, four types of melamine group-containing (meth)acrylates of formula (1) shown in Table 1 below were synthesized.

For comparison, an acrylate derived from hexamethylolmelamine was synthesized by the following procedure.

Hexamethylolmelamine 45.3f, 2-hydroxyethyl acrylate 200f. ．． 500ml of p-methoxyphenol and 8y of concentrated sulfuric acid were stirred for 1 hour at 3C)C. The resulting mixture was extracted with ethyl acetate/n-hexane, washed with a saturated aqueous solution of sodium bicarbonate, washed with water, and the organic layer was concentrated to obtain an acrylate (compound A) represented by the following formula.
A viscous liquid was obtained. 1 part of benzoin isobutyl ether and 4 parts of methyl isobutyl ketone were mixed with 50 parts of each of the above five (meth)acrylates, and 5 parts of methyl isobutyl ketone were mixed.
Various coating solutions were prepared.

The coating was applied onto a 100 μm thick polyethylene terephthalate stretched film (3 times the length and 3 times the width) using a Pa-J coater (#5), dried with hot air at 120° C., and then cured with ultraviolet rays.

For each coated molded product obtained, the adhesion, abrasion resistance,
Moisture resistance was evaluated. Adhesion: Cross cut test Abrasion resistance: Falling sand test (JIST-814 pier) force
- Borundum (#80) Haze value after falling 500f (%) Moisture resistance: Moisture resistance test 5 (generations), 20 days under 100% relative humidity
After being left for a while, the appearance and abrasion resistance were evaluated.

i Appearance and abrasion resistance do not change or hardly change.

2 Appearance remains unchanged, but wear resistance slightly decreases.

3 Appearance remains unchanged, but wear resistance decreases.

4 Both appearance and wear resistance change.

5. Both appearance and abrasion resistance change significantly.

Example 7 A coating solution consisting of part melamine group-containing acrylate (a) of Example 1, 1 part lauroyl peroxide, and 5 parts isopropyl alcohol was prepared, applied onto a sheet made of polybutylene terephthalate, and dried at 120°C. Then, heat curing was performed at 1500C.

The coated surface of the obtained polyester coated molding was hardly scratched even when rubbed with steel wool (#0000).
Moreover, the evaluation result of the moisture resistance was 2.

Claims (1)

[Claims] The following general formula ▲ includes numerical formulas, chemical formulas, tables, etc. ▼ [However, in the formula, R_1_1, R_1_2, R_1_3 are each independently a hydrogen atom or a methyl group;
_2_2 and R_2_3 each independently have 2 to 10 carbon atoms
is an alkylene group; R_3_1, R_3_2, R_
3_3 is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, and a formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula R
_1_0 is a hydrogen atom or a methyl group, and R_2_0 is an alkylene group having 2 to 10 carbon atoms. ) is a group selected from the group consisting of groups represented by ]
A polyester molded product coated with a vinyl polymer mainly composed of a melamine group-containing (meth)acrylate represented by: