JP3279768B2 - Resin composition having pearl luster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having a pearly luster, having high fluidity and well-balanced thermal and mechanical properties.

[0002]

2. Description of the Related Art In general, in order to obtain a resin composition exhibiting pearl luster without using a highly toxic pearl pigment, it is effective to mix a plurality of transparent resins having remarkably different melt viscosities and different refractive indexes. It is believed that there is. Tokiko 47-16063
As disclosed in the publication, a composition comprising an aromatic polycarbonate resin and an acrylic resin gives a resin composition having pearl luster. However, this composition is disadvantageous in that the high heat resistance, which is one of the advantages of the aromatic polycarbonate resin, is relatively greatly reduced, and the low flowability, which is a disadvantage, is not so much improved. JP-A-2-284949 discloses a composition in which an acrylic resin is used as a copolymer of methyl methacrylate and α-methylstyrene for the purpose of improving the heat resistance, and the composition is mixed with an aromatic polycarbonate resin. I have. However, this composition is inferior in mechanical properties, and the low flowability is not significantly improved. In any of the compositions obtained by adding such an acrylic resin, the flowability is not sufficiently improved unless the acrylic resin is added far beyond the amount required for imparting pearl luster. When it increases, there is a problem that thermal and mechanical properties are greatly reduced. For this reason, the composition has a problem that it is difficult to obtain a large-sized and thin-walled molded product, and its use is limited to decorative articles and other miscellaneous goods.

[0003]

An object of the present invention is to provide a resin composition having pearl luster, high fluidity and well-balanced thermal and mechanical physical properties, and having few restrictions on applications. With the goal.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, by adding an aliphatic polyester having a specific structure different from that of an acrylic resin to an aromatic polycarbonate resin, The inventors have found that the object has been achieved, and have completed the present invention. That is, the present invention provides an aromatic polycarbonate resin, polylactic acid and / or
Or a resin comprising a copolymer of lactic acid and another hydroxycarboxylic acid (hereinafter collectively referred to as a lactic acid-based resin), having a pearl luster, having a high fluidity and well-balanced thermal and mechanical properties. It relates to a composition.

[0005] The aromatic polycarbonate resin used in the present invention is a product produced by reacting a dihydric phenol with a carbonate precursor by a known method such as a solution method and a melting method. Representative dihydric phenols include hydroquinone, resorcinol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, and 2,2-bis (4-hydroxy-3,5- Dimethylphenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4 -Hydroxyphenyl) sulfone and the like. In particular, bis (4-hydroxyphenyl) alkanes are preferable, and 2,2-bis (4-hydroxyphenyl) propane, which is usually called bisphenol A, is particularly preferable. Examples of the carbonate precursor include carbonyl halide, carbonyl ester, and haloformate. Specific examples include phosgene, diphenyl carbonate, and dihaloformate of dihydric phenol. In the production of the polycarbonate resin, an appropriate molecular weight regulator, a branching agent, and other modifiers may be added. Further, each of the dihydric phenol and the carbonate precursor can be used alone or in combination of two or more, and the obtained polycarbonate resin may be used in combination of two or more. In the present invention, a polycarbonate resin containing bisphenol A as a main material gives good results.

[0006] Among the lactic acid-based resins in the present invention, polylactic acid is synthesized from a cyclic dimer of lactic acid, usually called lactide, by ring-opening polymerization.
1,995,970, USP 2,362,511 and USP 2,683,136. Copolymers of lactic acid and other hydroxycarboxylic acids are usually synthesized by ring-opening polymerization from a cyclic ester intermediate of lactide and hydroxycarboxylic acid, and their production methods are described in USP 3,635,956, USP 3,797,49
9 When a lactic acid-based resin is produced by direct dehydration polycondensation instead of ring-opening polymerization, lactic acid and optionally another hydroxycarboxylic acid are preferably azeotroped in the presence of an organic solvent, particularly a phenyl ether-based solvent. A lactic acid-based resin having a degree of polymerization suitable for the present invention by dehydration-condensation, particularly preferably by polymerizing by a method of returning a substantially anhydrous solvent to a reaction system by removing water from a solvent distilled off by azeotropic distillation. Is obtained. L- and L-
Any of D-lactic acid, a mixture thereof, and lactide, which is a dimer of lactic acid, can be used. Other hydroxycarboxylic acids that can be used in combination with lactic acids include glycolic acid and 3-hydroxycarboxylic acid.
Hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid and the like, and furthermore, a cyclic ester intermediate of hydroxycarboxylic acid, for example, glycolide which is a dimer of glycolic acid And ε-caprolactone, which is a cyclic ester of 6-hydroxycaproic acid, can also be used. In the production of the lactic acid-based resin, an appropriate molecular weight regulator, a branching agent, other modifiers, and the like may be added. In addition, any of lactic acids and hydroxycarboxylic acids as a copolymer component can be used alone or in combination of two or more, and the obtained lactic acid-based resins may be used in combination of two or more. In the present invention, polylactic acid, which is a polymer of only lactic acids, is suitably used, and a poly-L-lactic acid resin containing L-lactic acid as a main raw material is particularly preferable.

The molecular weight of the aromatic polycarbonate resin and lactic acid resin used in the present invention is not particularly limited. Generally, an aromatic polycarbonate resin has a much higher melt viscosity than a lactic acid-based resin. For example, even if the aromatic polycarbonate resin has a weight average molecular weight of about 50,000 used for normal injection molding, and the weight average molecular weight of the lactic acid-based resin is 100,000, which is twice that of the lactic acid-based resin, melting at a temperature within the molding processing range is possible. The viscosity of the aromatic polycarbonate resin is about several tens to several hundreds times larger than that of the aromatic polycarbonate resin, and there is no hindrance to the expression of pearl luster and the effect of improving the fluidity. Therefore, it is preferable that the molecular weight of the lactic acid-based resin is large from the viewpoint of thermal and mechanical properties, and specifically, a resin having a weight average molecular weight of 30,000 or more is suitable. In the composition of the present invention, the aromatic polycarbonate resin and the lactic acid-based resin are used in an arbitrary ratio, but in order to better express the pearl luster, which is a feature of the present invention, the former is 10 to 90% by weight, and the latter is the latter. However, a proportion of 90 to 10% by weight gives good results.
In terms of thermal and mechanical properties, the former is 50-90% by weight,
It can be said that the latter is particularly preferably in the range of 50 to 10% by weight.

In the above composition, various elastomers, plasticizers, pigments, stabilizers, mold release agents, flame retardants, other additives and fillers are used for the purpose and application as long as the properties of the present invention are not impaired. It can be used appropriately according to the requirements. The method for producing the resin composition of the present invention is not particularly limited, and a generally known method can be employed. That is, after the aromatic polycarbonate resin, lactic acid-based resin and other necessary components are uniformly mixed with a high-speed stirrer or the like, a single-screw or multi-screw extruder having sufficient kneading ability, a mixing roll, a kneader, a Brabender, etc. It can be produced by a method such as melt kneading. It is also effective to dissolve and swell both components in chloroform or another suitable solvent, stir mechanically or by using ultrasonic waves, and then evaporate the solvent to concentrate.

[0009]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the description, “%”, “part”, and “molecular weight” are based on weight unless otherwise specified. The weight average molecular weight was measured by gel permeation chromatography, and was shown as a value in terms of polystyrene. Examples 1-3
By the methods disclosed in Japanese Patent publication flat 4-504731, dried
In a 500 ml round bottom flask, put 56 g of L-lactic acid,
Flow nitrogen continuously through the inlet and outlet of the stopper
The mixture was heated under a stopper at 123 to 129 ° C. for about 1 hour.
The melt was swirled to mix thoroughly. catalyst
The solution was prepared by azeotropic distillation and dried. That is, 10 ml
Stannous octoate was dissolved in 60 ml of toluene. Very small amount
10 ml of toluene along with water was vented through the drying tube.
Distilled into a Dee Stark trap. 0.20ml
Pipette the stannous octoate solution into the melt with a pipette.
Mix thoroughly. Continue purging with nitrogen and heat to 123
Continued at 127127 ° C. for 20-24 hours. Cool mixture to room temperature
And cool the flask further with liquid nitrogen from behind the shield
After that, a colorless and transparent polymer was obtained. Manufacturing the weight average molecular weight 110,000 poly L- lactic acid resin (hereinafter abbreviated as "lactic acid resin 1") and polycarbonate resin (Teijin Kasei Co., Ltd.,
Panlite L-1225) was blended in the proportions shown in Table 1 and then thoroughly mixed with a tumbler mixer to obtain a screw diameter of 37 m.
The mixture was melt-mixed at a melting temperature of 250 ° C. and a screw rotation speed of 80 rpm by a twin screw extruder with m / L / D = 32 and extruded to obtain a pellet-shaped molding material composition. The composition obtained by the above method is
Molded into test pieces with an injection molding machine set at 280-250 ° C,
Each physical property was measured. Table 1 shows the results. It was possible to impart pearl luster while maintaining high fluidity and well-balanced physical properties.

Example 4 A poly-DL-lactic acid resin having a weight average molecular weight of 110,000 (hereinafter abbreviated as "lactic acid-based resin 2") was similarly evaluated. Table 2 shows the results. In this case, good results were obtained. Example 5 Similarly, a copolymer resin having a weight average molecular weight of 100,000 (hereinafter abbreviated as “lactic acid-based resin 3”) comprising 80 parts of L-lactic acid and 20 parts of glycolic acid was similarly evaluated. Table 2 shows the results. In this case, good results were obtained. Example 6 Similarly, a copolymer resin having a weight average molecular weight of 100,000 and consisting of 80 parts of L-lactic acid and 20 parts of 6-hydroxycaproic acid (hereinafter abbreviated as “lactic acid resin 4”) was similarly evaluated. Table 2 shows the results. In this case, good results were obtained.

Comparative Examples 1 to 3 Instead of the lactic acid resins 1 to 4 used in Examples 1 to 6, a high-flow type acrylic resin (Kuraray Co., Ltd., Parapet GF1000, hereinafter referred to as "acrylic resin 1") (Abbreviation). Table 3 shows the results. In this case, if the amount of the acrylic resin 1 is small, the effect of improving the fluidity is poor, and if the amount is large, the impact value, tensile rupture strength, tensile rupture elongation, heat deformation temperature, etc. are inferior. Comparative Examples 4 to 6 Instead of the lactic acid-based resins 1 to 4 used in Examples 1 to 6, a high-flow-type styrene-acrylic copolymer resin (manufactured by Daicel Chemical Industries, Ltd., Sebian MAS30, hereinafter referred to as “acrylic resin”) 2 "). Table 4 shows the results. In this case, if the amount of the acrylic resin 2 is small, the effect of developing pearl luster and the effect of improving the fluidity are poor, and if the amount is large, the impact value, tensile rupture strength, tensile rupture elongation, heat deformation temperature, etc. are inferior. . Comparative Example 7 This is the result of performing the same evaluation using the polycarbonate resin alone. Table 4 shows the results.

In the above Examples and Comparative Examples, each physical property was evaluated in the following manner. (1) Izod impact test (impact value) It was based on JIS-K7110. (2) Tensile test (tensile breaking strength, breaking elongation) It was based on JIS-K7113. (3) Bending test (flexural modulus, bending yield strength) It was based on JIS-K7113. (4) Heat deformation temperature Based on JIS-K7207. (5) Spiral flow flow length Archimedes-type spiral mold (flow thickness 1 mm, flow width
The flow length was measured under the conditions of a resin temperature of 280 ° C. and a mold temperature of 100 ° C. Further, when the flow length is 3 times or more the flow length of the aromatic polycarbonate resin alone at the same injection pressure, the flowability improving effect is large, and when the flow length is 2 to 3 times, it is small.
Two times or less was rated as insufficient improvement. (6) Pearl Gloss It was determined visually. Here, those having a clear pearl luster were regarded as having a pearl luster, and the following three grades were used: those having insufficient pearl luster and those having no pearl luster.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

[Table 4]

[0017]

The resin composition having pearl luster of the present invention can impart pearl luster while having a high degree of fluidity and well-balanced thermal and mechanical properties, and can be used as a conventional pearlescent resin. Applications are not limited to various applications, and applications to various fields are possible.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-49-53948 (JP, A) JP-A-49-129748 (JP, A) JP-A-50-19852 (JP, A) JP-A-2- 284949 (JP, A) JP-A-54-142049 (JP, A) JP-A-49-16742 (JP, A) JP-B-47-1663 (JP, B1) JP-B-49-33103 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 67/04 C08L 69/00

Claims (1)

(57) [Claims] 1. A resin composition comprising an aromatic polycarbonate resin and a copolymer of polylactic acid and / or lactic acids and another hydroxycarboxylic acid.