JP2000264977A - Polycarbonate resin molding product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarbonate resin molding product improved and prevented in coloring property due to weather resistance and high-temperature processing, or the like, by molding a cover layer and a core layer to both of which a triazine-based light stabilizer having a specific structure is added by co-extrusion. SOLUTION: When a core layer comprising a thermoplastic aromatic polycarbonate resin and a cover layer comprising a thermoplastic aromatic polycarbonate resin which exists on at least one face of the core layer are subjected to co-extrusion to provide a molding product, a resin obtained by adding 0.1-25 pts.wt. triazine-based light stabilizer of the formula (R1 is a 1-17C alkyl; R2 is H or a 1-4C alkyl) to 100 pts.wt. thermoplastic aromatic polycarbonate is used as the cover layer. Furthermore, it is preferable that the thickness of the cover layer is 5-100 μm. A polymer carbonate of bisphenol is preferable as the thermoplastic aromatic polycarbonate resin used. The resultant molding product is useful as a molding product for food packaging vessels, automobile interior and exterior materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article of a thermoplastic aromatic polycarbonate having improved weather resistance and coloring properties, and more particularly, to a core layer made of a thermoplastic aromatic polycarbonate resin and at least one surface of the core layer. In a polycarbonate resin molded product in which a cover layer made of a thermoplastic aromatic polycarbonate resin that is present is coextruded, the cover layer contains a triazine-based light stabilizer and has improved lightfastness and improved coloring properties due to high-temperature processing and the like. The present invention relates to a molded article of a polycarbonate resin used for food packaging containers, interior and exterior materials for automobiles, various molded products such as various precision machines, films, building materials, and the like.

[0002]

2. Description of the Related Art Polycarbonate resins have high strength and rigidity, and are excellent in abrasion resistance, chemical resistance, and transparency. Widely used for food packaging containers, automobile parts, various precision machine parts, etc. However, the polycarbonate resin has insufficient weather resistance,
For example, in outdoor use or indoor use under fluorescent lamp irradiation, the use has been significantly restricted due to discoloration or reduction in strength of the product. For this reason, various light stabilizers have heretofore been used alone or in combination of several kinds. In particular, benzotriazole-based light stabilizers are generally used because their effects are relatively large, but with regard to weather resistance, Although the effect is recognized to some extent, the problem of the coloring property due to the high-temperature processing is still insufficient, and further improvement is required.

Further, the surface of a polycarbonate resin is easily damaged by strong ultraviolet irradiation, and the surface of a naturally glossy polycarbonate is fogged by a number of extremely fine cracks. Therefore, in order to protect the surface of the polycarbonate resin, a resin molded product in which a cover layer containing an ultraviolet absorber is formed by co-extrusion is disclosed in
It has been proposed in JP-A-101360. Further, in Japanese Patent Application Laid-Open No. 1-165419, although fogging due to irradiation with ultraviolet rays has been solved to some extent, after adding a large amount of an ultraviolet absorbent, a molded article is co-extruded at a very high temperature of 300 ° C. or more into two layers. Due to the molding process, there is a problem that the resin is colored. Further, British Patent 2290745
In the publication, a co-extruded polycarbonate resin molded product containing a triazine-based ultraviolet absorber in a cover layer is described, but sufficient weather resistance cannot be obtained due to poor compatibility with a resin component.

Accordingly, an object of the present invention is to provide a polycarbonate resin molded article in which a core layer and a cover layer are formed by co-extrusion, and have improved weatherability and coloring properties due to high-temperature processing and the like.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that in a polycarbonate resin molded product in which a core layer and a cover layer are formed by co-extrusion, a triazine having a specific structure is formed on the cover layer. It has been found that a polycarbonate resin molded product to which a system light stabilizer is added can achieve the above object.

The present invention has been made on the basis of the above findings, and has a polycarbonate having a core layer made of a thermoplastic aromatic polycarbonate resin and a cover layer present on at least one surface of the core layer and formed by co-extrusion. In the resin molded product, the cover layer is formed as follows:
Provided is a polycarbonate resin molded product comprising a thermoplastic aromatic polycarbonate resin containing 0.1 to 25 parts by weight of a triazine-based light stabilizer represented by the general formula (1) (same as the above [Chemical formula 1]). Things.

[0007]

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[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a polycarbonate resin molded product of the present invention will be described in detail based on preferred embodiments.

The thermoplastic aromatic polycarbonate resin used in the present invention is preferably a high molecular carbonate ester of bisphenol. Examples of the bisphenol used here include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as “bisphenol-A”) 2,2-bis (4-hydroxy -3-methylphenyl) propane,
4,4-bis (hydroxyphenyl) heptane, 2,2
-Bis (4-hydroxy-3,5-dichlorophenyl)
Bisphenols such as propane, 2,2 bis (4-hydroxy-3,5-dibromophenyl) propane; bis (4-hydroxyphenyl) ether, bis (3,5
Dihydric phenol ethers such as -dichloro-4-hydroxyphenyl) ether; dihydroxydiphenyl such as p, p'-dihydroxydiphenyl, 3,3'-dichloro-4,4'-dihydroxydiphenyl;
Bis (4-hydroxyphenyl) sulfone, bis (3
Dihydroxyarylsulfones such as 5-dimethyl-4-hydroxyphenyl) sulfone; dihydroxybenzenes such as 1,4-dihydroxy-2,5-dichlorobenzene and 1,4-dihydroxy-3-methylbenzene; resorcinol; Hydroquinone, halo and alkyl substituted dihydroxybenzene, and bis (4-hydroxyphenyl) sulfoxide, bis (3,5-dibromo-4)
-Hydroxyphenyl) sulfoxide and the like. In addition, various bisphenols and trisphenols other than the above are also used to obtain the above polycarbonate resin. Further, in order to prepare the polycarbonate resin, a mixture of the above-mentioned bisphenol and the like can be used.

The thermoplastic aromatic polycarbonate resin is prepared, for example, by reacting a dihydric phenol with a carbonate precursor. As the carbonate precursor, carbonyl halide, carbonate ester or haloformate is used. Examples of the carbonyl halide include carbonyl bromide, carbonyl chloride, and mixtures thereof. Examples of the carbonate ester include diphenyl carbonate, di (chlorophenyl) carbonate, di (tolyl carbonate, dinaphthyl carbonate, and a mixture thereof. Examples of the haloformate include hydroquinone bischloroformate And glycol haloformates such as ethylene glycol haloformate, among which carbonyl chloride, known as phosgene, is particularly preferred.

The thermoplastic aromatic polycarbonate resin is prepared by using a molecular weight modifier and an acid acceptor, such as phenol, cyclohexanol, methanol, p-tert-butylphenol and p-bromophenol. And the like, and p-tert-butylphenol is preferably used. Examples of the acid acceptor include an organic or inorganic acid acceptor. Examples of the organic acid acceptor include pyridine, triethylamine, and dimethylaniline.Examples of the inorganic acid acceptor include an alkali or alkaline earth metal. Hydroxide, carbonate, bicarbonate or phosphate.

In the triazine-based light stabilizer represented by the general formula (1) used in the present invention, the alkyl group represented by R ₁ may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl. , Tertiary butyl, pentyl, second pentyl, tertiary pentyl, hexyl, isohexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl, nonyl, decyl, isodecyl, undecyl,
Dodecyl, tridecyl, tetradecyl and the like.

Examples of the alkyl group represented by R ₂ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl.

As the triazine light stabilizer represented by the general formula (1), more specifically, the following compound No.
1 to No. 6 and the like.

[0015]

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[0016]

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[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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The method for synthesizing the triazine-based light stabilizer represented by the general formula (1) is not particularly limited, and any commonly used method for synthesizing a triaryltriazine compound may be used. For example, Compound No. 1 is 2
-(2,4-dihydroxyphenyl) -4,6-di-
The desired product can be obtained by esterifying (2,4-diphenyl) triazine.

The polycarbonate resin molded product of the present invention comprises:
A molded article of a polycarbonate resin in which a core layer made of the thermoplastic aromatic polycarbonate resin and a cover layer made of the thermoplastic aromatic polycarbonate resin present on at least one surface of the core layer are co-extruded.

The polycarbonate resin molded product of the present invention comprises:
A thermoplastic aromatic polycarbonate resin plasticized by blending additives required in advance is press-fitted as a core layer and a cover layer by using one or more extruders to form a core layer and a cover layer.
It is co-extruded at a temperature between 400C and 400C. Since both the core layer and the cover layer are thermoplastic aromatic polycarbonate resins, the two layers have equal extensibility, so that even under stress, increased crack formation in the cover layer does not occur and adhesion after extrusion is achieved. Good nature.

The thermoplastic aromatic polycarbonate resin as the core layer may contain, if necessary, additives usually used, for example, light stabilizers, heat stabilizers, antioxidants, fillers, pigments, antistatic agents and the like. Can be added.

Although the thickness of the core layer is not particularly limited, it has a thickness of 2 mm to 10 mm for normal use. Typically, the core layer is flat, but may be corrugated, domed, or otherwise three-dimensionally shaped. Further, the core layer may contain one or more hollow chambers.

The cover layer is provided so as to cover at least one surface of the core layer, and is made of a thermoplastic aromatic polycarbonate resin containing a triazine light stabilizer represented by the above general formula (1). It is.

The amount of the triazine-based light stabilizer represented by the general formula (1) is 0.1 to 100 parts by weight of the thermoplastic aromatic polycarbonate resin in the cover layer.
It is 25 parts by weight, preferably 0.5 to 15 parts by weight.

When the amount of the above-mentioned triazine-based light stabilizer is 0.
If the amount is less than 1 part by weight, sufficient effects on the weather resistance of the polycarbonate resin cannot be obtained. Conversely, if the amount exceeds 20 parts by weight, there is a problem such as bleeding, and further effects cannot be expected.

If necessary, other antioxidants, light stabilizers, fillers, pigments, antistatic agents and the like can be added to the cover layer.

The thickness of the cover layer is preferably 5 to 100 μm, more preferably 20 to 50 μm. When the thickness is less than 5 μm, there is a possibility that the effect as the cover layer may not be obtained. When the thickness exceeds 100 μm, the cover layer is too thick with respect to the core layer, so that more additives than necessary are required. It may be uneconomical to be blended.

The polycarbonate resin molded product of the present invention comprises:
It is appropriately used for food packaging containers, automobile interior and exterior materials, various molded products such as various precision machines, films, building materials, and the like.

[0033]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The synthesis examples of the compounds used in the examples are shown below.

Synthesis Example: Compound No. Synthesis of 2 47 g (0.3 mol) of benzamidine hydrochloride and 33 g (0.14 mol) of phenyl resorcinate were added to ethanol 1
Dissolved in 95 g, 58 g (0.3 mol) of a 28% by weight sodium methylate solution was added, and the reaction mixture was heated to 78 ° C. while stirring to distill off methanol.
After the removal of methanol, the mixture was stirred at 78 ° C for 20 hours, cooled to 5 ° C, and filtered to obtain a solid. The obtained solid was washed with methanol and water to obtain 18.4 g (yield) of pale yellow crystals [2- (2,4-dihydroxyphenyl) -4,6-diphenyl-4,6-diphenyl-s-triazine]. Rate 37.7
%).

The obtained 2- (2,4-dihydroxyphenyl) -4,6-diphenyl-4,6-diphenyl-s
To 17.0 g (0.05 mol) of triazine, 94.8 g (0.75 mol) of 2-bromoethanol and dimethylformamide were added, and a 48% by weight NaOH aqueous solution 2 was added at 85 ° C.
9.2 g (0.35 mol) was added dropwise, reacted at 85 ° C. for 10 hours, cooled, neutralized with concentrated hydrochloric acid, and the precipitate was separated by filtration, washed with water,
After drying, 15.4 g of 2-hydroxy-4- (2-hydroxyethyloxy) phenyl-4,6-diphenyl-s-triazine (hereinafter referred to as “HETr”) (yield: 8).
0%). To 15 g (0.039 mol) of the obtained HETr, 10 g (0.116 mol) of methacrylic acid, xylene and 0.6 g of p-toluenesulfonic acid were added.
For 10 hours. After washing with water, recrystallization from a xylene / methanol (1: 3) solvent gave 16.9 g (85% yield) of a pale yellow solid having a melting point of 109 ° C.

The ¹ H-NMR chemical shift (proton number, assignment) of the obtained compound was 0.8-2.5 (15H,
Octyl _{group), 4.2-4.6 (4H, -OCH 2} CH
₂ O-), 6.5-6.8 (2H, Ar-H (Ar-O
), 7.4-7.8 (6H, Ar-H (Ar-
H), 8.4-8.8 (5H, Ar-H (Ar
Adjacent to -T: T is triazine)) 13.5 (1H, -O
H (hydrogen bonding)). The infrared absorption spectrum was 3300-3500 cm ⁻¹ , 2800-3200
^{cm -1, 1720cm -1, 1630cm -1} , 1590c
^{m -1, 1530cm -1, 1440cm -1} , 1420cm
^-1 , 1370 cm ^-1 , 1350 cm ^-1 , 1260c
It showed an absorption peak at m ^-1 and 1180 cm ^-1 .

Example 1 A bisphenol A polycarbonate powder having an intrinsic viscosity of 0.57 (in dioxane, 30 ° C.) is used as a core layer material. In addition, a bisphenol A polycarbonate powder having an intrinsic viscosity of 0.57 (in dioxane, at 30 ° C.) was used as a sample compound to obtain compound No. 1 which is a triazine-based light stabilizer represented by the general formula (1). 1 to 1
0% by weight was added and mixed in an extruder at 280 ° C. and 80 rpm to granulate the extrudate. This is used as a cover layer material. The core layer material and the cover layer material were co-extruded simultaneously at 280 ° C., and the corresponding surfaces were brought into contact with each other immediately after the extrusion to prepare a test piece having a thickness of 2 mm (core layer) +50 μm (cover layer). Using the above test piece, AS
The degree of yellowness was measured in accordance with TM D 1925, its YI was determined, and the colorability was evaluated. Further, using this test piece, 1 was measured using a sunshine weather meter (with rain).
The color difference ΔYI after the ultraviolet irradiation for 000 hours was measured, and the weather resistance was evaluated. Table 1 shows the results.

(Examples 2 to 7) The types of the sample compounds were designated Compound No. 2-No. Example 1 except for changing to 7
A test piece was prepared in the same manner as described above, and the same evaluation was performed. Table 1 shows the results.

Comparative Example 1 A coextruded test piece of a polycarbonate resin was prepared in the same manner as in Example 1 without mixing the sample compound in the cover layer, and the same evaluation was performed. Table 1 shows the results.

(Comparative Examples 2-3) The sample compounds to be mixed in the cover layer were the following Comparative Compound Nos. 1 (Comparative Example 2), Comparative Compound No. A test piece was prepared and evaluated in the same manner as in Example 1 except that the test piece was changed to 2 (Comparative Example 3). Table 1 shows the results.

[0041]

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[0042]

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[0043]

[Table 1]

As shown in Table 1, when a triazine-based light stabilizer having a specific structure (the above-mentioned general formula (1)) according to the present invention is used (Example), coloring and weather resistance can be achieved without impairing the appearance of the polycarbonate resin. It was confirmed that the property was improved at the same time. On the other hand, when a triazine-based light stabilizer having no ester structure was used (Comparative Example 2), there was a problem in coloring immediately after processing and in coloring by ultraviolet irradiation as compared with the examples of the present invention. Furthermore, when a triazine-based light stabilizer having an ester structure but a different number of substituents was used (Comparative Example 3), there was also a problem in coloring immediately after processing and coloring by ultraviolet irradiation.

Therefore, when the triazine-based light stabilizer according to the present invention was contained in the polycarbonate resin (Example), the case where a conventionally known triazine-based light stabilizer was used (Comparative Example) was used. Coloration by high temperature processing,
It is clear that the weather resistance is remarkably excellent.

[0046]

The polycarbonate resin molded product of the present invention has improved weather resistance and coloring properties due to high-temperature processing and the like.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keishi Ayabe 5-2-13-1 Shirahata, Urawa-shi, Saitama Asahi Denka Kogyo Co., Ltd. (72) Inventor Saiko Kawaki 5-2-13-Shirahata, Urawa-shi, Saitama Asahi Denka Kogyo Co., Ltd. GL00 GM00 GN00

Claims (2)

[Claims] 1. A molded article of a polycarbonate resin in which a core layer made of a thermoplastic aromatic polycarbonate resin and a cover layer made of a thermoplastic aromatic polycarbonate resin present on at least one surface of the core layer are formed by co-extrusion. The cover layer is composed of a resin obtained by adding 0.1 to 25 parts by weight of a triazine-based light stabilizer represented by the following general formula (1) to 100 parts by weight of a thermoplastic aromatic polycarbonate resin. Resin molding. Embedded image 2. The thickness of the cover layer is 5 to 100 μm.
The polycarbonate resin molded product according to claim 1, which is: